Fabrication and capacitive performance of cement-based electrode for structural supercapacitor

Fabrication and capacitive performance of cement-based electrode for structural supercapacitor | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Short Report Fabrication and capacitive performance of cement-based electrode for structural supercapacitor Yuhao Shen, Guangyuan Zhao, Ting Deng, Huangyi Deng, Limei Zhang, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6868638/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 11 You are reading this latest preprint version Abstract As traditional energy sources continue to deplete, the development of electrodes aimed at improving energy storage has become a promising approach to mitigate the energy crisis. Additionally, the cement-based electrode possesses advantages such as low cost and easy fabrication, which contribute to its promising potential for applications in batteries, capacitors, and especially supercapacitors. However, cement-based electrode also has the disadvantages of large resistance and unclear fitting circuit, which limit its practical use. Two types of cement-based carbon-doped electrodes were prepared by blending conductive activated carbon with ordinary cement. In one approach, gold was deposited onto the electrode surface, while in another, polytetrafluoroethylene (PTFE) was used to adhere the electrode to aluminum foil. The electrode treated with PTFE-coated aluminum foil shows a lower specific capacitance of 0.045 F/cm² at 10 mA/cm² and a higher resistance (15.7 Ω·cm²). However, it is surprising that the surface gold-sprayed electrode displays superior electrochemical performance, exhibiting a specific capacitance of 0.058 F/cm² at 10 mA/cm² and a low resistance (6.4 Ω·cm²). More importantly, at the higher current density of 50 mA cm − 2 , 95% of the capacitance is retained. This result provides an ideal host for the practical application of cement-based carbon-doped electrodes. Cement Activated carbon Electrochemical performance Supercapacitors Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 1. Introduction Nowadays, with the continuous depletion of traditional energy sources, fabricating an electrode designed to improve energy storage has become a promising method to alleviate the energy crisis. Compared with dielectric capacitors and batteries, supercapacitors have ultra-high-power performance, that is, short charging time, making them a popular direction for existing energy storage systems [ 1 – 3 ]. The performance of electrochemical capacitors composed of electrode, electrolyte and separator depends on many factors, but the electrode material is the main factor that determines the electrochemical performance [ 4 ]. Electrochemical energy storage devices can be categorised into three main types: electric double-layer energy storage devices, pseudo-capacitor energy storage devices, and hybrid-capacitor energy storage devices based on their charge storage mechanism [ 5 , 6 ]. In the electric double layer energy storage device, when the electrode is immersed in the electrolyte with carbon aerogel, graphene, carbon black and other carbon materials as the main materials, the negative ions and positive ions in the electrolyte are attracted to migrate to the positive and negative electrodes respectively to form an electric double layer, so it has a high-power density [ 7 – 9 ]. Whereas the capacitor or battery in which the electrode materials in pseudo-capacitor energy storage devices (Nickel, cobalt and other metal oxides, conductive polymers) are underpotentially deposited in a two-dimensional space on its surface or inside, and the energy is usually stored by a rapid reversible redox reaction (several times more than electric double-layer energy storage devices) [ 10 , 11 ]. However, compared with electric double layer energy storage devices, its low conductivity and ion diffusion rate are more difficult to meet the actual needs. Furthermore, the material of pseudo-capacitor energy storage devices itself often greatly shortens its service life due to the redox reaction in the electrochemical test [ 12 ]. For electric double-layer energy storage devices, it is of great research potential to improve its energy density, which depends on the specific capacitance and voltage window of the electrode material [ 13 , 14 ]. Whereas, specific capacitance form electric double-layer energy storage devices largely depends on the large specific surface area, light weight, good structural stability and the functionality of a single surface or whole in the nano-domains of the electrode materials [ 15 , 16 ]. Water and cement, as electrodes or electrolytes, have been proved to be used in electric double-layer energy storage devices in a wide range of studies, and have certain results on their specific capacitance and energy density [ 8 , 17 – 21 ]. The carbon-doped electrodes which have the characteristics of porous, good electrochemical stability and low price have been maturely used in electrochemical energy storage structures [ 22 – 25 ]. The rich pore structure in general building materials can accommodate metal salts and water to form pore solutions, which are pores [ 26 ]. Because the movement of the porous solution provides sufficient paths. This ionic conductor characteristic enhances the design potential of cement as an electrochemical energy storage device for building structure [ 27 ]. The application of cement in electrochemistry can not only alleviate the energy problem, but also put forward the new development direction of the industry in combination with architecture and electrochemistry. Thus, the aim of this study is to evaluate the electrochemical performance and microscopic mechanism of the electrodes which are made by dry mixing of cement, water and conductive activated carbon under gold spraying on its surface or polytetrafluoroethylene (PTFE) bonding its surface to aluminum foil. Herein, the production of 14% carbon-doped cement from being cast into a silicone flexible mold is reported. Furthermore, the impedance fitting circuit diagram, charge and discharge performance and specific capacitance, microscopic surface morphology, composition uniformity and other physical and electrochemical properties of electrodes of 14% carbon-doped cement is under-taken. As the carrier of energy storage device, cement can not only alleviate the energy problem, but also put forward the new development direction of the industry in combination with architecture and electrochemistry. 2. Experimental 2.1. Preparation of cement-carbon composite material The activated carbon is supplied by KURARAY from Japan whose model is YP-80F.The ordinary portland cement is produced in Mianyang, Sichuan, China. Materials were prepared as a dry mix of China cement powder and activated carbon, at defined AC-to-C mass rations (14%wt). Water was under continuous stirring to obtain a target water-to-cement mass ratio. The fresh cement-carbon paste was cast into a silicone flexible mold of 10*10*5 (mm) cube, which defined the geometric area (A = 1 cm 2 ) of the electrodes. The samples were immersed in a lime/water solution during the hydration process. Hardened samples were demolded after at least 28 days, following standard concrete engineering protocols [ 8 ]. After the surface of the block was polished with a sequence of SiC papers of decreasing abrasiveness, the sample pieces were completed. The preparation process of the carbon-cement electrode is schematically illuminated in Fig. 1 . 2.2. Electrode preparation The surface of the samples was treated by two methods to make the adsorption of electrons on the electrode surface stronger. The gold coating influences the current response by modifying both the surface chemistry and morphology of the material [ 28 – 30 ]. The prepared electrode samples were put into the gold sprayer, and the complete electrode sheet was obtained after 10 times of 30 s gold spray treatment (The prepared electrodes are called SE). The coated area per electrode was about 1cm 2 . The binder treatment method, which involves the use of PTFE and the addition of conductive activated carbon powder as a conductive agent (with a solid-to-liquid ratio of 1:1), has been widely employed in the preparation of electrodes by pasting the current collector (aluminum foil) onto the surface of the sample [ 5 , 7 ] (The prepared electrodes are called PE). For electrochemical measurements, the electrode is thoroughly cleaned and dried following surface treatment, then saturated in a 1 M KCl electrolyte solution. It is subsequently placed in a measurement device to serve as the working electrode. Selection of KCl as the electrolyte is advantageous for our electrode performance. Ag/AgCl (3M KCl) and Carbon Stick electrodes were used as reference and counter electrodes, respectively. 2.3. Characterization of the electrode sample X-ray diffraction (XRD) measurements were conducted using a PANalytical X'Pert PRO system, with Cu Kα radiation (wavelength λ = 1.54187 Å) for the structural characterization of the carbon-doped cement specimens. The surface morphology of the carbon-cement specimens was analyzed by Field emission scanning electron microscope (FE-SEM, Carl Zeiss Ultra 55). And element mapping of the specimens was obtained using an Energy Dispersive X-ray Spectrometer (EDX) with the TESCAN MAIA3LMU system [ 31 , 32 ]. X-ray photoelectron spectroscopy (XPS, Thermo Fisher Scientific ESCALAB 250Xi) investigation was carried out to illuminate the composition and chemical state of the element. The reaction thermal stability of carbon-cement specimens was tested by simultaneous thermogravimetry-differential scanning calorimetry (TG/DSC, NETZSCH 449F5). The AutoPore V 9600 automatic mercury porosimeter (maximum working pressure 60,000 psia, measurable pore size 3-1100000 nm) was used to test pore size distribution, pore structure, Mercury advance and retreat curves of carbon-doped cement specimen. 2.4. Electrochemical measurements The electrochemical performance of carbon cement electrode at room temperature was studied by electrochemical workstation (CHI660E) in three electrode configurations. The electrochemical performance of the carbon-doped electrode was obtained by cyclic voltammetry. All the samples were electrochemically activated through cyclic voltammetry tests at scan rates of 20/50/100/200/500 (mVs -1 ). The voltage window was adjusted from − 1 V to 0 V vs. Ag / AgCl (3M KCl). The specific capacitance and other properties are obtained and calculated by constant current charge and discharge test which was carried out for 8 cycles at a current of 10 / 20 / 50 mA· cm 2 . The specific capacitance (Cs) were calculated from GCD measurements with the following equation: Where I (A) represents the current, t (s) represents the discharge time, A (cm²) is the cross-sectional area, and V (V) is the total voltage window. Impedance and other information are provided by AC impedance test. In the frequency range of 0.01 Hz ~ 10 k Hz, the electrochemical impedance spectroscopy ( EIS ) test was carried out using a 5 mV AC frequency amplitude to investigate the equivalent series resistance and phase angle. 3. Results and discussion 3.1 Micro-structure and composition analysis 3.1.1. The thermal stability of carbon-cement specimen The samples of 1.7-2.0 mg were accurately weighed and placed in an alumina crucible. The sample was then heated from 35°C to 300°C in a nitrogen atmosphere at a heating rate of 10°C min − 1 and a nitrogen flow rate of 60 mL min − 1 [ 33 , 34 ]. Thermogravimetry variations of 28-day Carbon-cement specimen with increase of temperature is shown in Fig. 2 . The TG-DTG curves show that one weight-loss stage occur in microsphere sample. As can be seen, there is obvious weight loss in the range of 40–240℃, which may be due to the thermal decomposition of C-S-H structural water [ 36 ]. The thermal decomposition process can be divided into three parts (A, B, C). In the A-B process, the main decomposition is adsorbed water, and the decomposition rate decreases with the decomposition. After passing point B, the B-C process is mainly C-S-H dehydration, and the decomposition rate increases with the decomposition. After passing point C, C-H begins to dehydrate, resulting in a stable thermal decomposition rate. Once the temperature exceeds 240℃, the TG-DTG curves of the carbon-cement sample tends to be smooth. Moreover, it is also observed that the weight loss of the Carbon-cement sample is 12.045% of 100–200℃ in this stage. As for DTG curve, the maximum weight loss rate was 0.15% · ℃ −1 . 3.1.2. Morphological characterization of carbon-cement specimen The SEM images of carbon-cement electrode are shown in Fig. 3 . Figure 3 a and 3 b reveal bulk and strip mixed colloidal structure with a large number of various pores. In addition, Fig. 3 c illustrates the 3D interconnected microporous structure of carbon and cement, confirming that the cement block is interconnected by a carbon network [ 37 ]. On the other hand, Fig. 3 d shows the magnification of the carbon-cement samples, revealing the important role of carbon in the random network of a slightly inhomogeneous porous texture. Figure 3 f, Fig. 3 g and Fig. 3 h are the distribution of C, O, Si, which show the uniform distribution of C on the surface of the sample. Therefore, the interconnected 3D porous channel morphology (Fig. 3 c) and relatively uniform carbon distribution (Fig. 3 f) observed in the specimens are expected to facilitate rapid electrolyte diffusion and enhance charge transfer, thereby promoting the performance of carbon-doped cement blocks in energy storage devices [ 38 ]. 3.1.3. Structural characterization of carbon-cement specimen Figure 4 shows the XRD pattern of carbon-cement samples after hydration. As can be seen in this figure, there are three main characteristic peaks. The most obvious diffraction peaks at 2θ of about 29.3°, which is consistent with CaCO 3 (PDF#00–005–0586),Ca(OH) 2 (PDF#00–004–0733) and Ca 3 SiO 5 (PDF#00–014–0693). The diffraction peaks at 2θ of about 32.2°is assigned to Ca 3 SiO 5 (PDF#00–014–0693). The diffraction peaks at 2θ of about 39.4° belongs to CaCO 3 (PDF#00–005–0586). This proves from the diffraction level that the cement-based sample contains Ca, O, Si, which is consistent with the SEM-EDS results, and is well hydrated. However, Since the activated carbon used is amorphous, no corresponding diffraction peak is observed in the XRD pattern. 3.1.4. Pore structure and pore size distribution of carbon-cement electrode The characteristic parameters of mercury intrusion porosimetry (MIT) are shown in Table 2 and Table 3 . Figure 5 shows the mercury advance and retreat curve, pore volume distribution. According to the pore classification scheme of scholar Bout, the pores of cement-based materials are divided into four types: macropores (> 1000 nm), capillary pores (100 nm-1000 nm), transition pores (10 nm-100 nm) and gel pores (< 10 nm) [ 39 ]. It can be seen that the mercury advance and retreat curve of the carbon-cement electrode can be divided into five parts from Fig. 3 a. The 1–3 stage mainly reflects the process of filling the large pore volume, in which the absorption rate of mercury decreases with the increase of pressure. The absorption rate of mercury in the 3–4 stage is greatly reduced by comparison, and the specimen is compressed at this time. In the 4–5 stage, as the pressure increases further, the transition hole begins to be injected with mercury. After stage 5, even the gel pores are gradually filled with pressure. For the Carbon-cement electrode, in Table 3 , Table 4 and Fig. 3 b, the average pore diameter is 26.44nm, which belongs to the transition pore, which is consistent with the image that the main peak appears in 10 nm − 100 nm in the pore volume-pore size distribution curve, indicating that the transition pore contributes the most to the pore volume, with a contribution rate of 42.3%. The transition pore is the transport channel for electrolyte ions to diffuse into the gel pore, and the pore with appropriate pore size is the main place to form the electric double layer of the capacitor [ 40 ]. It can be seen from Table 3 that the large pores contribute 39.51% of the pore volume, which will lead to the poor retention of electrons in the cement-based material, which is characterized by capacitance performance. Table 1 List of carbon-cement specimen and mix design (m is the mass of carbon, m w is the mass of water and m c is the mass of cement) m w / m c m/ m c m c (kg/m 3 ) m w (kg/m 3 ) 0.6 0.14 421 253 Table 2 Characteristic parameters of pore structure of carbon-cement electrode Total intrusion volume (mL/g) Total pore area(m 2 /g) Porosity (%) Average pore diameter (nm) 0.2365 35.78 27.49 26.44 Table 3 Pore size distribution of pore structure of carbon-cement electrode Proportion of pore volume (%) Gel pores( 1000nm) 5.13 42.3 13.06 39.51 Table 4 Atomic ratios of the carbon-cement specimen powders obtained based on XPS measurement Elements C (%) O (%) Si (%) Ca (%) wt% 46.11 40.92 3.86 8.10 3.1.5. Element composition of carbon-cement specimen The chemical composition and elemental chemical state of the samples were analyzed by XPS technique the samples were analyzed by XPS technique [ 41 ]. It can be seen that the XPS spectra of carbon-cement specimen is presented in Fig. 6 and the content of each element is shown in Table 3 . In Fig. 6 and Table 3 , the presence of all the chemical component of the carbon-cement specimen were detected from the survey XPS spectra. The high-resolution XPS spectra for C, O, Si, and Ca reveal distinct photoelectron peaks corresponding to the composition of each spin-orbit component, respectively in Fig. 6 b. As seen from Table 3 , the carbon content is 46.11%, which provides a basis for the use of carbon-cement electrodes in an electrochemical environment. 3.2. Electrochemical property of carbon-cement electrodes 3.2.1. Electrochemical analysis The CV curves at scan rates of 20, 50, 100, 200, 500 mV s − 1 over the carbon-cement electrodes are shown in Fig. 5 . Compared with Fig. 5 b, it shows a quasi-rectangular shape and has a more obvious cyclic reversibility. Generally, the CV curves can be used to estimate the ability of ion diffusion/transfer within the carbon-droped structure when curves are quasi-rectangular [ 42 ]. It proves that this carbon-doped porous structure enables the electrode to exchange electrons and ions in the electrolyte. The CV curves of carbon-cement electrodes in Fig. 5 a at different scan rates reveal the superb capacitive behavior even under the high scan rate of 500 mV s − 1 . Moreover, the cyclic voltammetry test curve of the carbon-doped cement-based electrode, with PTFE as the binder in the surface treatment of aluminum foil, reveals a smaller enclosed area compared to that of the gold-sprayed carbon-doped cement-based electrode. This suggests that the gold-sprayed electrode possesses a larger specific capacitance and superior electrochemical performance. Spray-gold treatment can interduce more active sites, which promote the transfer of electrons, leading to a smoother behavior of electron motion in the electrode, strengthened the ability of electron transfer, and thus lowering the internal resistance. 3.2.2. Galvanostatic charge-discharge (GCD) The GCD curves at a current density of 10、20、50 (see Fig. 6 a, 6 b) exhibit the Isosceles-like triangle feature of the two surface-treated carbon-cement electrodes, revealing mixed electrical double and layer and pseudocapacitive contributions. Furthermore, the curve of the gold-sprayed carbon-doped cement electrode has a small deviation from linearity. In the two electrode surface treatments, the aluminum in the aluminum foil paper is more likely to react chemically in the KCl electrolyte than the gold alloy film sprayed with gold. Moreover, it is shown that the carbon-cement electrodes under the two surface treatments can be normal charge and discharge. Besides, according to Eq. ( 1 ), the specific capacitance of gold-sprayed carbon-cement electrode (14%wt) at 10 mA cm − 2 is obtained, Cs = 0.058F/cm 2 . The specific capacitance reached 0.058F/cm 2 at 10 mA cm − 2 and dropped to 0.055 F/cm 2 at 50 mA cm − 2 in Fig. 5 a, but the specific capacitance of the other surface treatment electrode reached 0.045F/cm 2 at 10 mA cm − 2 and dropped to 0.035 F/cm 2 at 50 mA cm − 2 in Fig. 5 b. The diffusion limit of electrolyte ions makes it impossible for ions to reach the inner surface area of the micropores of the carbon-cement electrode, resulting in insufficient utilization of the entire porous active material, resulting in a lower specific capacitance at high current than at low current [ 43 , 44 ]. The PTFE-treated electrode surface will block the tiny voids of the electrode and affect the movement of ions and electrons, resulting in a smaller specific capacitance than the gold-sprayed electrode, which is consistent with the cyclic voltammetry test curve. The capacitance performance of cement-based electrode is consistent with the pore size distribution of MIT test results. The superior electrochemical performance of the gold-sprayed electrode can be attributed to its ability to enhance the electron adsorption capacity of the electrode surface, without compromising the integrity of the electrode's porous structure. 3.2.3. Electrochemical impedance spectroscopy test (EIS) To advance the analysis of the kinetic properties of electrode materials, the electrochemical impedance spectra of the Car-bon-cement samples were examined as shown in Fig. 7 . EIS analysis can be used to determine the resistance to charge transfer and the efficiency of charge separation. The arc of the EIS Nyquist is the high frequency reaction zone, representing electron transfer. In general, the small radius of the Nyquist circle represents that the charge transfer resistance is low. The straight line of the EIS Nyquist is a low frequency reaction zone, representing ion transfer [ 45 ]. The EIS Nyquist plot is also presented in terms of the equivalent circuit model (the inset of Fig. 7 ). Furthermore, the arc projection sizes of gold-spraying electrode and aluminum foil electrode are obtained, R 2 = 6.9 Ω and R 2 = 15.7 Ω, respectively, which prove gold-spraying electrode has smaller resistances. Moreover, this is consistent with the results of cyclic voltammetry test curve. Using the method of spraying gold to deal with the contact surface between the carbon cement electrode and the electrode clamp can make the resistance lower, which proves that the cement-based material has potential in the energy storage equipment. 4. Conclusion In summary, the carbon-cement electrodes, fabricated using two different surface treatment methods, have been successfully applied in the field of electrochemistry. The microscopic physical form and electrochemical properties of these two carbon-doped cement electrodes (14%wt) were investigated. The results show that this carbon cement electrode has a large number of transition pores, and the surface of the electrode has sufficient and sufficient carbon as a conductive agent in terms of distribution and content, which provides conditions for electrochemical testing of the electrode. Both carbon-cement electrodes can be successfully charged and discharged which have a stable electrochemical cycle in the electrochemical system. Furthermore, these two electrodes both can make electrons adsorb on the electrode surface, so that the GCD curve shows pseudocapacitance characteristics. The superior electrochemical performance of the gold-sprayed electrode can be attributed to its ability to enhance the electron adsorption capacity of the electrode surface, without compromising the integrity of the electrode’s porous structure. At the same time, the fitting circuit of the AC impedance spectrum of the electrode was successfully revealed. This indicates that carbon-cement electrode is a promising candidate for large quantity, low price capacitors, while the electrode under the spray gold treatment has better electrochemical performance and more potential. Declarations Author Contribution Y wrote the manuscript G(2), T collated the data H, L prepared the chart C, J revised the chartG(8) , L(9),L(10) revised the graph All authors reviewed the manuscript Acknowledgements This work was supported by the National Natural Science Foundation of China [No. 52378263 and No. 52178254]. References T. Liu, G. Liu (2019) Block copolymers for supercapacitors, dielectric capacitors and batteries. J Condens Matter Phys 31:233001.https://doi.org/10.1088/1361-648X/ab0d77 D. G. Wang, Z. Liang, S. Gao, C. Qu, R. Zou (2020) Metal-organic framework-based materials for hybrid supercapacitor application. Coordin Chem Rev 404:213093-213093. https://doi.org/10.1016/j.ccr.2019.213093 B. Jim, B. Sofiane, K. Igor, S. Mark, Y. Gleb (2014) Multifunctional CNT-polymer composites for ultra-tough structural supercapacitors and desalination devices. Adv Mater 1606-1606.https://doi.org/10.1002/adma.201301317 H.A. Khan, M. Tawalbeh, B. Aljawrneh, W. Abuwatfa, A.A. Othman, H. Sadeghifar, A.G. Olabi (2024) A comprehensive review on supercapacitors: Their promise to flexibility, high temperature, materials, design, and challenges. Energy 295:131043. https://doi.org/10.1016/j.energy.2024.131043 C. Amrane, K. E. Bouhidel (2018) Integrated diffusion dialysis precipitation - cementation for selective recovery of leaching chemicals and metal values from electroplating sludge. Hydrometallurgy 177:34-40. https://doi.org/10.1016/j.hydromet.2018.02.011 P. Zhu, Z. Zhang, P. Zhao, B. Zhang, X. Cao, J. Yu, J. Cai, Y. Huang, Z. Yang (2019) Rational design of intertwined carbon nanotubes threaded porous CoP @ carbon nanocubes as anode with superior lithium storage. Carbon 142:269-277. https://doi.org/10.1016/j.carbon.2018.10.066 X. Liu, H. Mi, P. Chen (2017) A dual functional wrapping layer for enhanced cyclic performance of high-loading silicon anodes. Electrochimi Acta 240:1-6.https://doi.org/10.1016/j.electacta.2017.04.036 N. Chanut, D. Stefaniuk, J.C. Weaver, Y. Zhu, Y. Shao-Horn, A. Masic, F.-J. Ulm (2023) Carbon–cement supercapacitors as a scalable bulk energy storage solution. P Natl A Sci 120.https://doi.org/10.1073/pnas.2304318120 L.E. Asp, E.S. Greenhalgh (2014) Structural power composites. Compos Sci Technol 101:41-61.https://doi.org/10.1016/j.compscitech.2014.06.020 Y. Xu, W. Lu, G. Xu, T. Chou (2021) Structural supercapacitor composites: A review. Compos Sci Technol 204:108636.https://doi.org/10.1016/j.compscitech.2020.108636 D.D.L. Chung (2018) Development, design and applications of structural capacitors. Appl Energy 231:89-101.https://doi.org/10.1016/j.apenergy.2018.09.132 X. Luo, D.D.L. Chung (2001) Carbon-fiber/polymer-matrix composites as capacitors. Compos Sci Technol 61:885-888.https://doi.org/10.1016/S0266-3538(00)00166-4 S. Natasha, Q. Hui, H. Matthieu, J. H. G. Steinke, A. R. J. Kucernak, Q. P. V. Fontana, E. S. Greenhalgh, B. Alexander, M. S. P. Shaffer (2014) Multifunctional structural energy storage composite supercapacitors. Faraday Discuss 172:81-103.https://doi.org/10.1039/C4FD00055B E. Greenhalgh, J. Ankersen, L. Asp, A. Bismarck, Q. Fontana, M. Houlle, G. Kalinka, A. Kucernak, M. Mistry, S. Nguyen, H. Qian, M. Shaffer, N. Shirshova, J. Steinke, M. Wienrich (2015) Mechanical, electrical and microstructural characterisation of multifunctional structural power composites. J Compos Mater 49:1823-1834.https://doi.org/10.1177/0021998314554125 K. Wang, L. Li, Y. Li, L. Tao, L. Wang, S. Yuan, H. Yan, G. Chao (2024) Preparation of graphene carbon nanotube supercapacitor electrode materials for new energy vehicles Mater Technol 39. https://doi.org/10.1016/j.jmat.2016.01.001 M. Serwar, R. Sadiq, U.A. Rana, H.M. Siddiqi, A. Adomkevicius, J. A. C. Clemente, F. Braga, L. J. Hardwick (2025) Porous nitrogen-doped carbons derived from poultry feathers for electrochemical capacitors. J Phys Chem Solid 196:112393-112393.https://doi.org/10.1016/j.jpcs.2024.112393 Z. Tang, Q. Shi, Y. Fu (2006) Research progress of electrically conductive concrete. KSCE J Civ Eng 1:135-139. G. Song (2000) Equivalent circuit model for AC electrochemical impedance spectroscopy of concrete. Cement Concrete Res 30:1723-1730.https://doi.org/10.1016/S0008-8846(00)00400-2 A. Bediwy, M. Bassuoni (2017) Resistivity, penetrability and porosity of poncrete: a tripartite relationship. J Test Eval 46:20160374-20160374.https://doi.org/10.1520/JTE20160374 Z. Liu, Y. Zhang, Q. Jiang (2014) Continuous tracking of the relationship between resistivity and pore structure of cement pastes. Constr Build Mater 53:26-31.https://doi.org/10.1016/j.conbuildmat.2013.11.067 X. Hu, C. Shi, X. Liu, Z. Zhang (2020) Studying the effect of alkali dosage on microstructure development of alkali-activated slag pastes by electrical impedance spectroscopy (EIS). Constr Build Mater 261:119982.https://doi.org/10.1016/j.conbuildmat.2020.119982 Z. Liu, P. Feng, R. Liu, L. Yuan, X. Meng, G. Tao, J. Chen, Q. Ran, J. Hong, J. Liu, C. Miao (2024) Integration of zinc anode and cement: unlocking scalable energy storage. Natl Sci Rev 11.https://doi.org/10.1093/nsr/nwae309 H. Xu, S. Zhong, C. Yuan, X. Zheng, S. Wang (2024) Honeycomb-like N, S dual-doped porous carbons derived from pomelo peel by effective exogenous doping strategy for supercapacitor electrodes. Diam Relat Mater 150:111768-111768.https://doi.org/10.1016/j.diamond.2024.111768 B. Tan, H. Li, Q. Yuan, F. An (2024) Optimizing activated carbon electrodes and improving their electrochemical performance through nitrogen doping and HNO 3 modification. Mater Today Commun 41:110459-110459.https://doi.org/10.1016/j.mtcomm.2024.110459 J. Li, D. Wang, F. Meng, G. Wang (2025) Nitrogen and sulfur co-doped porous carbon obtained from direct carbonization of a renewable biomass for counter electrode of efficient dye-sensitized solar cells. Mater Sci Eng B- Adv 311:117778-117778.https://doi.org/10.1016/j.mseb.2024.117778 B.A. Salami, T.A. Oyehan, A. Tanimu, A.B. Olabintan, M. Ibrahim, M.O. Sanni Anibire, S.A. Nafiu, O. Arowojolu, T.A. Saleh (2022) Cement-based batteries design and performance. A review. Environ Chem Lett 20:1-24.https://doi.org/10.1007/s10311-022-01389-x Wang, D. Zhang (2022) Structural supercapacitor constructed by SnO2/graphene coated nickel foam electrode and synchronously synthesized polymer cement electrolyte at room temperature. Mater Chem Phys 277:125488.https://doi.org/10.1016/j.matchemphys.2021.125488 S.V. Lokesh, B.S. Sherigara, Jayadev, H.M. Mahesh, R.J. Mascarenhas (2008) Electrochemical reactivity of C60 modified carbon paste electrode by physical vapor deposition method. Int J Electrochem Sc 3: 578-587.https://doi.org/10.1016/S1452-3981(23)15545-3 K.M. Metz, P.E. Colavita, K.Y. Tse, R.J. Hamers (2011) Nanotextured gold coatings on carbon nanofiber scaffolds as ultrahigh surface-area electrodes. J Power Sources 198:393-401.https://doi.org/10.1016/j.jpowsour.2011.09.098 F.D.A.D.S. Silva, M.G.A.D. Silva, P.R. Lima, M.R. Meneghetti, L.T. Kubota, M.O.F. Goulart (2013) A very low potential electrochemical detection of l-cysteine based on a glassy carbon electrode modified with multi-walled carbon nanotubes/gold nanorods. Biosens Bioelectron 50:202-209.https://doi.org/10.1016/j.bios.2013.06.036 T. Deng, J. Li, G. Zhao, Y. Fu, J. Yuan, R. Xie, H. Huang, L. Su, H. Liu (2024) Visible-light photoelectric performance and bending stability of flexible LaCoO 3 /Mica thin films. Ceram Int 50:27165-27175.https://doi.org/10.1016/j.ceramint.2024.05.014 J. Wang, J. Wang, Y. Mao, R. Peng, F. Nie (2022) The surface activation of boron to improve ignition and combustion characteristic. Def Technol18:1679-1687.https://doi.org/10.1016/j.dt.2021.09.012 J. Wang, Y. Mao, J. Chen, Z. Li, J. Wang, F. Nie (2022) Surface engineering boron/graphite fluoride composite with enhanced ignition and combustion performances. Fuel 323.https://doi.org/10.1016/j.fuel.2022.124374 J. Wang, J. Chen, Y. Mao, Y. Deng, W. Cao, F. Nie, J. Wang (2024) Construct a 3D microsphere of HMX/B/Al/PTFE to obtain the high energy and combustion reactivity. Def Technol 32:45-54.https://doi.org/10.1016/j.dt.2023.07.016 C. Schlumberger, C. Scherdel, M. Kriesten, P. Leicht, A. Keilbach, H. Ehmann, P. Kotnik, G. Reichenauer, M. Thommes (2022) Reliable surface area determination of powders and meso/macroporous materials: Small-angle X-ray scattering and gas physisorption. Micropor Mesopor Mat 329:111554.https://doi.org/10.1016/j.micromeso.2021.111554 F. Chen, J. Wen, Y. Li, L. Liu, Y. Shi, Y. Lyu, B. Xing, J. Yang (2025) Effects of the modified expanded perlite materials on magnesium phosphate cement-based fireproof mortars: mechanical property. thermal conductivity and microstructure Case Stud Constr Mat 22:e04140.https://doi.org/10.1016/j.cscm.2024.e04140 Z. Liu, T. Huang, Y. Cao, C. Liu (2024) Permeability test and meso-structure analysis of biochar-cement soil. Rock Soil Mech 45:2929-2936.https://doi.org/10.16285/j.rsm.2023.1907 M. David, L. Zhi, Z.W. Xu, X.H. Tan, H.L. Wang, H. Chris, S. Tyler (2013) Mesoporous nitrogen-rich carbons derived from protein for ultra-high capacity battery anodes and supercapacitors. Energy Environ Sci 1:513-513.https://doi.org/10.1039/C2EE23599D W. She, Y. Zhang, C. Miao, J. Hong, S. Mu (2019) Water transport in foam concrete: visualisation and numerical modelling. Mag Concrete Res 72:734-746.https://doi.org/10.1680/jmacr.18.00190 Y. Wang, S. Zuo (2016) Electrochemical properties of phosphorus-pontaining activated carbon electrodes on electrical double-layer capacitors. Acta Phys-Chim Sin 32:481-492.https://doi.org/10.3866/PKU.WHXB201511041 T.P. Mokoena, Z.P. Tshabalala, K.T. Hillie, H.C. Swart, D.E. Motaung (2020) The blue luminescence of p-type NiO nanostructured material induced by defects: H 2 S gas sensing characteristics at a relatively low operating temperature, Appl Surf Sci 525: 146002.https://doi.org/10.1016/j.apsusc.2020.146002 H. Zhong, F. Xu, Z. Li, R. Fu, D. Wu (2013) High-energy supercapacitors based on hierarchical porous carbon with an ultrahigh ion-accessible surface area in ionic liquid electrolytes. Nanoscale 5:4678-4682.https://doi.org/10.1039/C3NR00738C F. Wu, M. Zhang, Y. Bai, X. Wang, R. Dong, C. Wu (2019) Lotus seedpod-derived hard carbon with hierarchical porous structure as stable anode for sodium-ion batteries. ACS Appl Mater Interfaces, 11:12554-12561.https://doi.org/10.1021/acsami.9b01419 D. M. Sayed, M.M. Taha, L.G. Ghanem, M.S. Deab, N.K. Allam (2020) Hybrid supercapacitors: A simple electrochemical approach to determine optimum potential window and charge balance . J Power Sources 480: 229152.https://doi.org/10.1016/j.jpowsour.2020.229152 Y. Qiu, J. Lu, Y. Yan, J. Niu (2022) Enhanced visible-light-driven photocatalytic degradation of tetracycline by 16% Er 3+ -Bi 2 WO 6 photocatalyst.J. Hazardous Mater 422:126920. https://doi.org/10.1016/j.jhazmat.2021.126920 Additional Declarations No competing interests reported. Supplementary Files GraphicalAbstract.tif.jpg Graphical abstract Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 27 Jun, 2025 Reviews received at journal 27 Jun, 2025 Reviews received at journal 23 Jun, 2025 Reviews received at journal 23 Jun, 2025 Reviewers agreed at journal 13 Jun, 2025 Reviewers agreed at journal 12 Jun, 2025 Reviewers agreed at journal 12 Jun, 2025 Reviewers invited by journal 12 Jun, 2025 Editor assigned by journal 11 Jun, 2025 Submission checks completed at journal 11 Jun, 2025 First submitted to journal 11 Jun, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6868638","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Short Report","associatedPublications":[],"authors":[{"id":470800523,"identity":"030550d6-7bd6-4d69-b0d2-48882cd50179","order_by":0,"name":"Yuhao Shen","email":"","orcid":"","institution":"Southwest University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Yuhao","middleName":"","lastName":"Shen","suffix":""},{"id":470800527,"identity":"38c366f7-1115-4f13-a404-9ac9f4847168","order_by":1,"name":"Guangyuan Zhao","email":"","orcid":"","institution":"Southwest University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Guangyuan","middleName":"","lastName":"Zhao","suffix":""},{"id":470800529,"identity":"26020377-7338-4eda-895e-1aad417e41ae","order_by":2,"name":"Ting Deng","email":"","orcid":"","institution":"Southwest University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Ting","middleName":"","lastName":"Deng","suffix":""},{"id":470800531,"identity":"fb6a958b-4cd7-4ee3-aac7-c25d78446e6f","order_by":3,"name":"Huangyi Deng","email":"","orcid":"","institution":"Southwest University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Huangyi","middleName":"","lastName":"Deng","suffix":""},{"id":470800532,"identity":"295cc68d-b374-4f67-90a7-830082018a02","order_by":4,"name":"Limei Zhang","email":"","orcid":"","institution":"Southwest University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Limei","middleName":"","lastName":"Zhang","suffix":""},{"id":470800534,"identity":"0f22f4b6-a15d-49ae-a063-385d36a69aa2","order_by":5,"name":"Chuanbei Liu","email":"","orcid":"","institution":"Southwest University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Chuanbei","middleName":"","lastName":"Liu","suffix":""},{"id":470800535,"identity":"667462e8-c0f0-450a-917d-a918b96e2c14","order_by":6,"name":"Jianwu Wen","email":"","orcid":"","institution":"Southwest University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Jianwu","middleName":"","lastName":"Wen","suffix":""},{"id":470800536,"identity":"2e797e4d-5fe8-4e6c-9400-71f4476906da","order_by":7,"name":"Gaoyin Zhang","email":"","orcid":"","institution":"Southwest University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Gaoyin","middleName":"","lastName":"Zhang","suffix":""},{"id":470800537,"identity":"7e0bbf52-96dd-43a2-8c9d-1716aba4a98e","order_by":8,"name":"Lihua Zhang","email":"","orcid":"","institution":"Southwest University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Lihua","middleName":"","lastName":"Zhang","suffix":""},{"id":470800538,"identity":"1aa28529-e1fd-409e-ae12-14d582ec4c7a","order_by":9,"name":"Haifeng Liu","email":"data:image/png;base64,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","orcid":"","institution":"Southwest University of Science and Technology","correspondingAuthor":true,"prefix":"","firstName":"Haifeng","middleName":"","lastName":"Liu","suffix":""},{"id":470800539,"identity":"0a48d8e6-dd2c-441e-ac6a-048e89d6153b","order_by":10,"name":"Laibao Liu","email":"","orcid":"","institution":"Southwest University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Laibao","middleName":"","lastName":"Liu","suffix":""}],"badges":[],"createdAt":"2025-06-11 06:53:27","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6868638/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6868638/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":84762018,"identity":"17d6dbb9-e0b7-48a3-9613-bd5ca1c3de39","added_by":"auto","created_at":"2025-06-17 06:14:35","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":106918,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic diagram for preparation process of the carbon-cement electrodes\u003c/p\u003e","description":"","filename":"Fig1.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6868638/v1/4ca402139f2703654dde1507.jpg"},{"id":84761235,"identity":"c1f0bc36-e960-449b-850c-689b020f02c8","added_by":"auto","created_at":"2025-06-17 06:06:35","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":103935,"visible":true,"origin":"","legend":"\u003cp\u003eTG-DTG curves of the carbon-cement specimen\u003c/p\u003e","description":"","filename":"Fig2.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6868638/v1/6f4e016ae5e04591e26c3e23.jpg"},{"id":84762019,"identity":"c2659375-bfc3-41d0-99c5-e9121ea775f5","added_by":"auto","created_at":"2025-06-17 06:14:35","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":143730,"visible":true,"origin":"","legend":"\u003cp\u003eSEM images and EDS elemental maps of thecarbon-cement specimen: (a-d) SEM images, (e-h) energy spectrum image of the selected frame region.\u003c/p\u003e","description":"","filename":"Fig3.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6868638/v1/3fdb36c1ee83ec16507b61d2.jpg"},{"id":84761243,"identity":"8fea7c83-a4ea-4463-8ab8-b2ddadb9405b","added_by":"auto","created_at":"2025-06-17 06:06:36","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":89425,"visible":true,"origin":"","legend":"\u003cp\u003eXRD patterns of the carbon-cement specimen\u003c/p\u003e","description":"","filename":"Fig4.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6868638/v1/3564e1b82863afed2fd456cc.jpg"},{"id":84761239,"identity":"29ba7acf-69df-42a6-81fe-b2c7f02b7f43","added_by":"auto","created_at":"2025-06-17 06:06:35","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":76319,"visible":true,"origin":"","legend":"\u003cp\u003eMercury injection porosity curve: (a) mercury advance and retreat isotherms (b) pore size-pore volume distribution\u003c/p\u003e","description":"","filename":"Fig5.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6868638/v1/6a9573b3682cb58973135b5c.jpg"},{"id":84761314,"identity":"d0d68241-ada4-492e-960d-b55a9dbd9ca8","added_by":"auto","created_at":"2025-06-17 06:07:26","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":102612,"visible":true,"origin":"","legend":"\u003cp\u003eXPS spectra of the carbon-cement specimen: (a) survey spectra, (b) high-resolution spectra of C, Si, O, Ca\u003c/p\u003e","description":"","filename":"Fig6.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6868638/v1/97170db746070b3c48e436cb.jpg"},{"id":84761240,"identity":"4b07832a-329e-4a38-9c60-1a67c062a3ce","added_by":"auto","created_at":"2025-06-17 06:06:35","extension":"jpg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":108695,"visible":true,"origin":"","legend":"\u003cp\u003eCyclic voltammogram of three electrodes: (a) SE, (b) PE\u003c/p\u003e","description":"","filename":"Fig7.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6868638/v1/493b62a05d75ed96d0a4cfbb.jpg"},{"id":84761319,"identity":"ec91a94e-cdc3-43b7-8f0f-2a4fdd4f2f5d","added_by":"auto","created_at":"2025-06-17 06:07:28","extension":"jpg","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":89662,"visible":true,"origin":"","legend":"\u003cp\u003eCharging and discharging test by constant current: (a) SE, (b) PE\u003c/p\u003e","description":"","filename":"Fig8.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6868638/v1/1217d12564248e3fb7b524ec.jpg"},{"id":84761317,"identity":"9198be13-7048-478c-a69b-3bc424d58da9","added_by":"auto","created_at":"2025-06-17 06:07:27","extension":"jpg","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":71784,"visible":true,"origin":"","legend":"\u003cp\u003eAC impedance test of three electrodes: (a) SE, (b) PE\u003c/p\u003e","description":"","filename":"Fig9.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6868638/v1/b20da4110738e98d657346c0.jpg"},{"id":84762204,"identity":"86ce9611-bd50-4696-b88b-434ae983e874","added_by":"auto","created_at":"2025-06-17 06:22:36","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1788229,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6868638/v1/fb94fb1b-eb50-4e19-aa19-276e39317215.pdf"},{"id":84761313,"identity":"90cc2b4b-8d8d-4a0f-9792-342b1357a4a6","added_by":"auto","created_at":"2025-06-17 06:07:05","extension":"jpg","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":5243380,"visible":true,"origin":"","legend":"\u003cp\u003eGraphical abstract\u003c/p\u003e","description":"","filename":"GraphicalAbstract.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6868638/v1/56ad0b983518bd4750bca6f4.jpg"}],"financialInterests":"No competing interests reported.","formattedTitle":"Fabrication and capacitive performance of cement-based electrode for structural supercapacitor","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eNowadays, with the continuous depletion of traditional energy sources, fabricating an electrode designed to improve energy storage has become a promising method to alleviate the energy crisis. Compared with dielectric capacitors and batteries, supercapacitors have ultra-high-power performance, that is, short charging time, making them a popular direction for existing energy storage systems [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. The performance of electrochemical capacitors composed of electrode, electrolyte and separator depends on many factors, but the electrode material is the main factor that determines the electrochemical performance [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Electrochemical energy storage devices can be categorised into three main types: electric double-layer energy storage devices, pseudo-capacitor energy storage devices, and hybrid-capacitor energy storage devices based on their charge storage mechanism [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. In the electric double layer energy storage device, when the electrode is immersed in the electrolyte with carbon aerogel, graphene, carbon black and other carbon materials as the main materials, the negative ions and positive ions in the electrolyte are attracted to migrate to the positive and negative electrodes respectively to form an electric double layer, so it has a high-power density [\u003cspan additionalcitationids=\"CR8\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Whereas the capacitor or battery in which the electrode materials in pseudo-capacitor energy storage devices (Nickel, cobalt and other metal oxides, conductive polymers) are underpotentially deposited in a two-dimensional space on its surface or inside, and the energy is usually stored by a rapid reversible redox reaction (several times more than electric double-layer energy storage devices) [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. However, compared with electric double layer energy storage devices, its low conductivity and ion diffusion rate are more difficult to meet the actual needs. Furthermore, the material of pseudo-capacitor energy storage devices itself often greatly shortens its service life due to the redox reaction in the electrochemical test [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFor electric double-layer energy storage devices, it is of great research potential to improve its energy density, which depends on the specific capacitance and voltage window of the electrode material [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Whereas, specific capacitance form electric double-layer energy storage devices largely depends on the large specific surface area, light weight, good structural stability and the functionality of a single surface or whole in the nano-domains of the electrode materials [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Water and cement, as electrodes or electrolytes, have been proved to be used in electric double-layer energy storage devices in a wide range of studies, and have certain results on their specific capacitance and energy density [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan additionalcitationids=\"CR18 CR19 CR20\" citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. The carbon-doped electrodes which have the characteristics of porous, good electrochemical stability and low price have been maturely used in electrochemical energy storage structures [\u003cspan additionalcitationids=\"CR23 CR24\" citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. The rich pore structure in general building materials can accommodate metal salts and water to form pore solutions, which are pores [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Because the movement of the porous solution provides sufficient paths. This ionic conductor characteristic enhances the design potential of cement as an electrochemical energy storage device for building structure [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. The application of cement in electrochemistry can not only alleviate the energy problem, but also put forward the new development direction of the industry in combination with architecture and electrochemistry.\u003c/p\u003e \u003cp\u003eThus, the aim of this study is to evaluate the electrochemical performance and microscopic mechanism of the electrodes which are made by dry mixing of cement, water and conductive activated carbon under gold spraying on its surface or polytetrafluoroethylene (PTFE) bonding its surface to aluminum foil. Herein, the production of 14% carbon-doped cement from being cast into a silicone flexible mold is reported. Furthermore, the impedance fitting circuit diagram, charge and discharge performance and specific capacitance, microscopic surface morphology, composition uniformity and other physical and electrochemical properties of electrodes of 14% carbon-doped cement is under-taken. As the carrier of energy storage device, cement can not only alleviate the energy problem, but also put forward the new development direction of the industry in combination with architecture and electrochemistry.\u003c/p\u003e"},{"header":"2. Experimental","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1. Preparation of cement-carbon composite material\u003c/h2\u003e \u003cp\u003eThe activated carbon is supplied by KURARAY from Japan whose model is YP-80F.The ordinary portland cement is produced in Mianyang, Sichuan, China. Materials were prepared as a dry mix of China cement powder and activated carbon, at defined AC-to-C mass rations (14%wt). Water was under continuous stirring to obtain a target water-to-cement mass ratio. The fresh cement-carbon paste was cast into a silicone flexible mold of 10*10*5 (mm) cube, which defined the geometric area (A\u0026thinsp;=\u0026thinsp;1 cm\u003csup\u003e2\u003c/sup\u003e) of the electrodes. The samples were immersed in a lime/water solution during the hydration process. Hardened samples were demolded after at least 28 days, following standard concrete engineering protocols [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. After the surface of the block was polished with a sequence of SiC papers of decreasing abrasiveness, the sample pieces were completed. The preparation process of the carbon-cement electrode is schematically illuminated in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2. Electrode preparation\u003c/h2\u003e \u003cp\u003eThe surface of the samples was treated by two methods to make the adsorption of electrons on the electrode surface stronger. The gold coating influences the current response by modifying both the surface chemistry and morphology of the material [\u003cspan additionalcitationids=\"CR29\" citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. The prepared electrode samples were put into the gold sprayer, and the complete electrode sheet was obtained after 10 times of 30 s gold spray treatment (The prepared electrodes are called SE). The coated area per electrode was about 1cm\u003csup\u003e2\u003c/sup\u003e. The binder treatment method, which involves the use of PTFE and the addition of conductive activated carbon powder as a conductive agent (with a solid-to-liquid ratio of 1:1), has been widely employed in the preparation of electrodes by pasting the current collector (aluminum foil) onto the surface of the sample [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] (The prepared electrodes are called PE). For electrochemical measurements, the electrode is thoroughly cleaned and dried following surface treatment, then saturated in a 1 M KCl electrolyte solution. It is subsequently placed in a measurement device to serve as the working electrode. Selection of KCl as the electrolyte is advantageous for our electrode performance. Ag/AgCl (3M KCl) and Carbon Stick electrodes were used as reference and counter electrodes, respectively.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3. Characterization of the electrode sample\u003c/h2\u003e \u003cp\u003eX-ray diffraction (XRD) measurements were conducted using a PANalytical X'Pert PRO system, with Cu Kα radiation (wavelength λ\u0026thinsp;=\u0026thinsp;1.54187 \u0026Aring;) for the structural characterization of the carbon-doped cement specimens. The surface morphology of the carbon-cement specimens was analyzed by Field emission scanning electron microscope (FE-SEM, Carl Zeiss Ultra 55). And element mapping of the specimens was obtained using an Energy Dispersive X-ray Spectrometer (EDX) with the TESCAN MAIA3LMU system [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. X-ray photoelectron spectroscopy (XPS, Thermo Fisher Scientific ESCALAB 250Xi) investigation was carried out to illuminate the composition and chemical state of the element. The reaction thermal stability of carbon-cement specimens was tested by simultaneous thermogravimetry-differential scanning calorimetry (TG/DSC, NETZSCH 449F5). The AutoPore V 9600 automatic mercury porosimeter (maximum working pressure 60,000 psia, measurable pore size 3-1100000 nm) was used to test pore size distribution, pore structure, Mercury advance and retreat curves of carbon-doped cement specimen.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.4. Electrochemical measurements\u003c/h2\u003e \u003cp\u003eThe electrochemical performance of carbon cement electrode at room temperature was studied by electrochemical workstation (CHI660E) in three electrode configurations. The electrochemical performance of the carbon-doped electrode was obtained by cyclic voltammetry. All the samples were electrochemically activated through cyclic voltammetry tests at scan rates of 20/50/100/200/500 (mVs\u003csup\u003e-1\u003c/sup\u003e). The voltage window was adjusted from \u0026minus;\u0026thinsp;1 V to 0 V vs. Ag / AgCl (3M KCl). The specific capacitance and other properties are obtained and calculated by constant current charge and discharge test which was carried out for 8 cycles at a current of 10 / 20 / 50 mA\u0026middot; cm\u003csup\u003e2\u003c/sup\u003e. The specific capacitance (Cs) were calculated from GCD measurements with the following equation:\u003c/p\u003e\u003cp\u003e\u003cimg src=\"data:image/png;base64,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\" width=\"564\" height=\"64\"\u003e\u003c/p\u003e \u003cp\u003eWhere I (A) represents the current, t (s) represents the discharge time, A (cm\u0026sup2;) is the cross-sectional area, and V (V) is the total voltage window.\u003c/p\u003e \u003cp\u003eImpedance and other information are provided by AC impedance test. In the frequency range of 0.01 Hz\u0026thinsp;~\u0026thinsp;10 k Hz, the electrochemical impedance spectroscopy ( EIS ) test was carried out using a 5 mV AC frequency amplitude to investigate the equivalent series resistance and phase angle.\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Results and discussion","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e3.1 Micro-structure and composition analysis\u003c/h2\u003e \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e \u003ch2\u003e3.1.1. The thermal stability of carbon-cement specimen\u003c/h2\u003e \u003cp\u003eThe samples of 1.7-2.0 mg were accurately weighed and placed in an alumina crucible. The sample was then heated from 35\u0026deg;C to 300\u0026deg;C in a nitrogen atmosphere at a heating rate of 10\u0026deg;C min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and a nitrogen flow rate of 60 mL min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e, \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. Thermogravimetry variations of 28-day Carbon-cement specimen with increase of temperature is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. The TG-DTG curves show that one weight-loss stage occur in microsphere sample. As can be seen, there is obvious weight loss in the range of 40\u0026ndash;240℃, which may be due to the thermal decomposition of C-S-H structural water [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]. The thermal decomposition process can be divided into three parts (A, B, C). In the A-B process, the main decomposition is adsorbed water, and the decomposition rate decreases with the decomposition. After passing point B, the B-C process is mainly C-S-H dehydration, and the decomposition rate increases with the decomposition. After passing point C, C-H begins to dehydrate, resulting in a stable thermal decomposition rate. Once the temperature exceeds 240℃, the TG-DTG curves of the carbon-cement sample tends to be smooth. Moreover, it is also observed that the weight loss of the Carbon-cement sample is 12.045% of 100\u0026ndash;200℃ in this stage. As for DTG curve, the maximum weight loss rate was 0.15% \u0026middot; ℃\u003csup\u003e\u0026minus;1\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section3\"\u003e \u003ch2\u003e3.1.2. Morphological characterization of carbon-cement specimen\u003c/h2\u003e \u003cp\u003eThe SEM images of carbon-cement electrode are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. Figure\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea and \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eb reveal bulk and strip mixed colloidal structure with a large number of various pores. In addition, Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ec illustrates the 3D interconnected microporous structure of carbon and cement, confirming that the cement block is interconnected by a carbon network [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. On the other hand, Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ed shows the magnification of the carbon-cement samples, revealing the important role of carbon in the random network of a slightly inhomogeneous porous texture. Figure\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ef, Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eg and Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eh are the distribution of C, O, Si, which show the uniform distribution of C on the surface of the sample. Therefore, the interconnected 3D porous channel morphology (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ec) and relatively uniform carbon distribution (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ef) observed in the specimens are expected to facilitate rapid electrolyte diffusion and enhance charge transfer, thereby promoting the performance of carbon-doped cement blocks in energy storage devices [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section3\"\u003e \u003ch2\u003e3.1.3. Structural characterization of carbon-cement specimen\u003c/h2\u003e \u003cp\u003eFigure\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e shows the XRD pattern of carbon-cement samples after hydration. As can be seen in this figure, there are three main characteristic peaks. The most obvious diffraction peaks at 2θ of about 29.3\u0026deg;, which is consistent with CaCO\u003csub\u003e3\u003c/sub\u003e (PDF#00\u0026ndash;005\u0026ndash;0586),Ca(OH)\u003csub\u003e2\u003c/sub\u003e (PDF#00\u0026ndash;004\u0026ndash;0733) and Ca\u003csub\u003e3\u003c/sub\u003eSiO\u003csub\u003e5\u003c/sub\u003e (PDF#00\u0026ndash;014\u0026ndash;0693). The diffraction peaks at 2θ of about 32.2\u0026deg;is assigned to Ca\u003csub\u003e3\u003c/sub\u003eSiO\u003csub\u003e5\u003c/sub\u003e (PDF#00\u0026ndash;014\u0026ndash;0693). The diffraction peaks at 2θ of about 39.4\u0026deg; belongs to CaCO\u003csub\u003e3\u003c/sub\u003e (PDF#00\u0026ndash;005\u0026ndash;0586). This proves from the diffraction level that the cement-based sample contains Ca, O, Si, which is consistent with the SEM-EDS results, and is well hydrated. However, Since the activated carbon used is amorphous, no corresponding diffraction peak is observed in the XRD pattern.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section3\"\u003e \u003ch2\u003e3.1.4. Pore structure and pore size distribution of carbon-cement electrode\u003c/h2\u003e \u003cp\u003eThe characteristic parameters of mercury intrusion porosimetry (MIT) are shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e and Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. Figure\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e shows the mercury advance and retreat curve, pore volume distribution. According to the pore classification scheme of scholar Bout, the pores of cement-based materials are divided into four types: macropores (\u0026gt;\u0026thinsp;1000 nm), capillary pores (100 nm-1000 nm), transition pores (10 nm-100 nm) and gel pores (\u0026lt;\u0026thinsp;10 nm) [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e]. It can be seen that the mercury advance and retreat curve of the carbon-cement electrode can be divided into five parts from Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea. The 1\u0026ndash;3 stage mainly reflects the process of filling the large pore volume, in which the absorption rate of mercury decreases with the increase of pressure. The absorption rate of mercury in the 3\u0026ndash;4 stage is greatly reduced by comparison, and the specimen is compressed at this time. In the 4\u0026ndash;5 stage, as the pressure increases further, the transition hole begins to be injected with mercury. After stage 5, even the gel pores are gradually filled with pressure. For the Carbon-cement electrode, in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eb, the average pore diameter is 26.44nm, which belongs to the transition pore, which is consistent with the image that the main peak appears in 10 nm \u0026minus;\u0026thinsp;100 nm in the pore volume-pore size distribution curve, indicating that the transition pore contributes the most to the pore volume, with a contribution rate of 42.3%. The transition pore is the transport channel for electrolyte ions to diffuse into the gel pore, and the pore with appropriate pore size is the main place to form the electric double layer of the capacitor [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]. It can be seen from Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e that the large pores contribute 39.51% of the pore volume, which will lead to the poor retention of electrons in the cement-based material, which is characterized by capacitance performance.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eList of carbon-cement specimen and mix design (m is the mass of carbon, m\u003csub\u003ew\u003c/sub\u003e is the mass of water and m\u003csub\u003ec\u003c/sub\u003e is the mass of cement)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003em\u003csub\u003ew\u003c/sub\u003e/ m\u003csub\u003ec\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003em/ m\u003csub\u003ec\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003em\u003csub\u003ec\u003c/sub\u003e(kg/m\u003csup\u003e3\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003em\u003csub\u003ew\u003c/sub\u003e(kg/m\u003csup\u003e3\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e421\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e253\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCharacteristic parameters of pore structure of carbon-cement electrode\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal intrusion volume (mL/g)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTotal pore area(m\u003csup\u003e2\u003c/sup\u003e/g)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePorosity\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAverage pore diameter (nm)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e0.2365\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e35.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e27.49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e26.44\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePore size distribution of pore structure of carbon-cement electrode\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c4\" namest=\"c1\"\u003e \u003cp\u003eProportion of pore volume (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGel pores(\u0026lt;\u0026thinsp;10nm)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTransitional\u003c/p\u003e \u003cp\u003epore (10nm-100nm)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCapillary\u003c/p\u003e \u003cp\u003eopening (10nm-100nm)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMacropore (\u0026gt;\u0026thinsp;1000nm)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e42.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e39.51\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAtomic ratios of the carbon-cement specimen powders obtained based on XPS measurement\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eElements\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eO (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSi (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCa (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ewt%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e46.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e40.92\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8.10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section3\"\u003e \u003ch2\u003e3.1.5. Element composition of carbon-cement specimen\u003c/h2\u003e \u003cp\u003eThe chemical composition and elemental chemical state of the samples were analyzed by XPS technique the samples were analyzed by XPS technique [\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e]. It can be seen that the XPS spectra of carbon-cement specimen is presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e and the content of each element is shown in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. In Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e and Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, the presence of all the chemical component of the carbon-cement specimen were detected from the survey XPS spectra. The high-resolution XPS spectra for C, O, Si, and Ca reveal distinct photoelectron peaks corresponding to the composition of each spin-orbit component, respectively in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eb. As seen from Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, the carbon content is 46.11%, which provides a basis for the use of carbon-cement electrodes in an electrochemical environment.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003e3.2. Electrochemical property of carbon-cement electrodes\u003c/h2\u003e \u003cdiv id=\"Sec15\" class=\"Section3\"\u003e \u003ch2\u003e3.2.1. Electrochemical analysis\u003c/h2\u003e \u003cp\u003eThe CV curves at scan rates of 20, 50, 100, 200, 500 mV s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e over the carbon-cement electrodes are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e. Compared with Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eb, it shows a quasi-rectangular shape and has a more obvious cyclic reversibility. Generally, the CV curves can be used to estimate the ability of ion diffusion/transfer within the carbon-droped structure when curves are quasi-rectangular [\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]. It proves that this carbon-doped porous structure enables the electrode to exchange electrons and ions in the electrolyte. The CV curves of carbon-cement electrodes in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ea at different scan rates reveal the superb capacitive behavior even under the high scan rate of 500 mV s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. Moreover, the cyclic voltammetry test curve of the carbon-doped cement-based electrode, with PTFE as the binder in the surface treatment of aluminum foil, reveals a smaller enclosed area compared to that of the gold-sprayed carbon-doped cement-based electrode. This suggests that the gold-sprayed electrode possesses a larger specific capacitance and superior electrochemical performance. Spray-gold treatment can interduce more active sites, which promote the transfer of electrons, leading to a smoother behavior of electron motion in the electrode, strengthened the ability of electron transfer, and thus lowering the internal resistance.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section3\"\u003e \u003ch2\u003e3.2.2. Galvanostatic charge-discharge (GCD)\u003c/h2\u003e \u003cp\u003eThe GCD curves at a current density of 10、20、50 (see Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ea, \u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eb) exhibit the Isosceles-like triangle feature of the two surface-treated carbon-cement electrodes, revealing mixed electrical double and layer and pseudocapacitive contributions. Furthermore, the curve of the gold-sprayed carbon-doped cement electrode has a small deviation from linearity. In the two electrode surface treatments, the aluminum in the aluminum foil paper is more likely to react chemically in the KCl electrolyte than the gold alloy film sprayed with gold. Moreover, it is shown that the carbon-cement electrodes under the two surface treatments can be normal charge and discharge. Besides, according to Eq.\u0026nbsp;(\u003cspan refid=\"Equ1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), the specific capacitance of gold-sprayed carbon-cement electrode (14%wt) at 10 mA cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e is obtained, Cs\u0026thinsp;=\u0026thinsp;0.058F/cm\u003csup\u003e2\u003c/sup\u003e. The specific capacitance reached 0.058F/cm\u003csup\u003e2\u003c/sup\u003e at 10 mA cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e and dropped to 0.055 F/cm\u003csup\u003e2\u003c/sup\u003e at 50 mA cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ea, but the specific capacitance of the other surface treatment electrode reached 0.045F/cm\u003csup\u003e2\u003c/sup\u003e at 10 mA cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e and dropped to 0.035 F/cm\u003csup\u003e2\u003c/sup\u003e at 50 mA cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eb. The diffusion limit of electrolyte ions makes it impossible for ions to reach the inner surface area of the micropores of the carbon-cement electrode, resulting in insufficient utilization of the entire porous active material, resulting in a lower specific capacitance at high current than at low current [\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e, \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e]. The PTFE-treated electrode surface will block the tiny voids of the electrode and affect the movement of ions and electrons, resulting in a smaller specific capacitance than the gold-sprayed electrode, which is consistent with the cyclic voltammetry test curve. The capacitance performance of cement-based electrode is consistent with the pore size distribution of MIT test results. The superior electrochemical performance of the gold-sprayed electrode can be attributed to its ability to enhance the electron adsorption capacity of the electrode surface, without compromising the integrity of the electrode's porous structure.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section3\"\u003e \u003ch2\u003e3.2.3. Electrochemical impedance spectroscopy test (EIS)\u003c/h2\u003e \u003cp\u003eTo advance the analysis of the kinetic properties of electrode materials, the electrochemical impedance spectra of the Car-bon-cement samples were examined as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e. EIS analysis can be used to determine the resistance to charge transfer and the efficiency of charge separation. The arc of the EIS Nyquist is the high frequency reaction zone, representing electron transfer. In general, the small radius of the Nyquist circle represents that the charge transfer resistance is low. The straight line of the EIS Nyquist is a low frequency reaction zone, representing ion transfer [\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e]. The EIS Nyquist plot is also presented in terms of the equivalent circuit model (the inset of Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e). Furthermore, the arc projection sizes of gold-spraying electrode and aluminum foil electrode are obtained, R\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;6.9 Ω and R\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;15.7 Ω, respectively, which prove gold-spraying electrode has smaller resistances. Moreover, this is consistent with the results of cyclic voltammetry test curve. Using the method of spraying gold to deal with the contact surface between the carbon cement electrode and the electrode clamp can make the resistance lower, which proves that the cement-based material has potential in the energy storage equipment.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003eIn summary, the carbon-cement electrodes, fabricated using two different surface treatment methods, have been successfully applied in the field of electrochemistry. The microscopic physical form and electrochemical properties of these two carbon-doped cement electrodes (14%wt) were investigated. The results show that this carbon cement electrode has a large number of transition pores, and the surface of the electrode has sufficient and sufficient carbon as a conductive agent in terms of distribution and content, which provides conditions for electrochemical testing of the electrode. Both carbon-cement electrodes can be successfully charged and discharged which have a stable electrochemical cycle in the electrochemical system. Furthermore, these two electrodes both can make electrons adsorb on the electrode surface, so that the GCD curve shows pseudocapacitance characteristics. The superior electrochemical performance of the gold-sprayed electrode can be attributed to its ability to enhance the electron adsorption capacity of the electrode surface, without compromising the integrity of the electrode\u0026rsquo;s porous structure. At the same time, the fitting circuit of the AC impedance spectrum of the electrode was successfully revealed. This indicates that carbon-cement electrode is a promising candidate for large quantity, low price capacitors, while the electrode under the spray gold treatment has better electrochemical performance and more potential.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eY wrote the manuscript G(2), T collated the data H, L prepared the chart C, J revised the chartG(8) , L(9),L(10) revised the graph All authors reviewed the manuscript\u003c/p\u003e\u003ch2\u003eAcknowledgements\u003c/h2\u003e \u003cp\u003eThis work was supported by the National Natural Science Foundation of China [No. 52378263 and No. 52178254].\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eT. Liu, G. Liu (2019) Block copolymers for supercapacitors, dielectric capacitors and batteries. J Condens Matter Phys 31:233001.https://doi.org/10.1088/1361-648X/ab0d77\u003c/li\u003e\n\u003cli\u003eD. G. Wang, Z. Liang, S. Gao, C. Qu, R. Zou (2020) Metal-organic framework-based materials for hybrid supercapacitor application. Coordin Chem Rev 404:213093-213093. https://doi.org/10.1016/j.ccr.2019.213093\u003c/li\u003e\n\u003cli\u003eB. Jim, B. Sofiane, K. Igor, S. Mark, Y. Gleb (2014) Multifunctional CNT-polymer composites for ultra-tough structural supercapacitors and desalination devices. Adv Mater 1606-1606.https://doi.org/10.1002/adma.201301317\u003c/li\u003e\n\u003cli\u003eH.A. Khan, M. Tawalbeh, B. Aljawrneh, W. Abuwatfa, A.A. Othman, H. Sadeghifar, A.G. Olabi (2024) A comprehensive review on supercapacitors: Their promise to flexibility, high temperature, materials, design, and challenges. Energy 295:131043. https://doi.org/10.1016/j.energy.2024.131043\u003c/li\u003e\n\u003cli\u003eC. Amrane, K. E. Bouhidel (2018) Integrated diffusion dialysis precipitation - cementation for selective recovery of leaching chemicals and metal values from electroplating sludge. Hydrometallurgy 177:34-40. https://doi.org/10.1016/j.hydromet.2018.02.011\u003c/li\u003e\n\u003cli\u003eP. Zhu, Z. Zhang, P. Zhao, B. Zhang, X. Cao, J. Yu, J. Cai, Y. Huang, Z. Yang (2019) Rational design of intertwined carbon nanotubes threaded porous CoP @ carbon nanocubes as anode with superior lithium storage. Carbon 142:269-277. https://doi.org/10.1016/j.carbon.2018.10.066\u003c/li\u003e\n\u003cli\u003eX. Liu, H. Mi, P. Chen (2017) A dual functional wrapping layer for enhanced cyclic performance of high-loading silicon anodes. Electrochimi Acta 240:1-6.https://doi.org/10.1016/j.electacta.2017.04.036\u003c/li\u003e\n\u003cli\u003eN. Chanut, D. Stefaniuk, J.C. Weaver, Y. Zhu, Y. Shao-Horn, A. Masic, F.-J. Ulm (2023) Carbon\u0026ndash;cement supercapacitors as a scalable bulk energy storage solution. P Natl A Sci 120.https://doi.org/10.1073/pnas.2304318120\u003c/li\u003e\n\u003cli\u003eL.E. Asp, E.S. Greenhalgh (2014) Structural power composites. Compos Sci Technol 101:41-61.https://doi.org/10.1016/j.compscitech.2014.06.020\u003c/li\u003e\n\u003cli\u003eY. Xu, W. Lu, G. Xu, T. Chou (2021) Structural supercapacitor composites: A review. Compos Sci Technol 204:108636.https://doi.org/10.1016/j.compscitech.2020.108636\u003c/li\u003e\n\u003cli\u003eD.D.L. Chung (2018) Development, design and applications of structural capacitors. Appl Energy 231:89-101.https://doi.org/10.1016/j.apenergy.2018.09.132\u003c/li\u003e\n\u003cli\u003eX. Luo, D.D.L. Chung (2001) Carbon-fiber/polymer-matrix composites as capacitors. Compos Sci Technol 61:885-888.https://doi.org/10.1016/S0266-3538(00)00166-4\u003c/li\u003e\n\u003cli\u003eS. Natasha, Q. Hui, H. Matthieu, J. H. G. Steinke, A. R. J. Kucernak, Q. P. V. Fontana, E. S. Greenhalgh, B. Alexander, M. S. P. Shaffer (2014) Multifunctional structural energy storage composite supercapacitors. Faraday Discuss 172:81-103.https://doi.org/10.1039/C4FD00055B\u003c/li\u003e\n\u003cli\u003eE. Greenhalgh, J. Ankersen, L. Asp, A. Bismarck, Q. Fontana, M. Houlle, G. Kalinka, A. Kucernak, M. Mistry, S. Nguyen, H. Qian, M. Shaffer, N. Shirshova, J. Steinke, M. Wienrich (2015) Mechanical, electrical and microstructural characterisation of multifunctional structural power composites. J Compos Mater 49:1823-1834.https://doi.org/10.1177/0021998314554125\u003c/li\u003e\n\u003cli\u003eK. Wang, L. Li, Y. Li, L. Tao, L. Wang, S. Yuan, H. Yan, G. Chao (2024) Preparation of graphene carbon nanotube supercapacitor electrode materials for new energy vehicles Mater Technol 39. https://doi.org/10.1016/j.jmat.2016.01.001\u003c/li\u003e\n\u003cli\u003eM. Serwar, R. Sadiq, U.A. Rana, H.M. Siddiqi, A. Adomkevicius, J. A. C. Clemente, F. Braga, L. J. Hardwick (2025) Porous nitrogen-doped carbons derived from poultry feathers for electrochemical capacitors. J Phys Chem Solid 196:112393-112393.https://doi.org/10.1016/j.jpcs.2024.112393\u003c/li\u003e\n\u003cli\u003eZ. Tang, Q. Shi, Y. Fu (2006) Research progress of electrically conductive concrete. KSCE J Civ Eng 1:135-139.\u003c/li\u003e\n\u003cli\u003eG. Song (2000) Equivalent circuit model for AC electrochemical impedance spectroscopy of concrete. Cement Concrete Res 30:1723-1730.https://doi.org/10.1016/S0008-8846(00)00400-2\u003c/li\u003e\n\u003cli\u003eA. Bediwy, M. Bassuoni (2017) Resistivity, penetrability and porosity of poncrete: a tripartite relationship. J Test Eval 46:20160374-20160374.https://doi.org/10.1520/JTE20160374\u003c/li\u003e\n\u003cli\u003eZ. Liu, Y. Zhang, Q. Jiang (2014) Continuous tracking of the relationship between resistivity and pore structure of cement pastes. Constr Build Mater 53:26-31.https://doi.org/10.1016/j.conbuildmat.2013.11.067\u003c/li\u003e\n\u003cli\u003eX. Hu, C. Shi, X. Liu, Z. Zhang (2020) Studying the effect of alkali dosage on microstructure development of alkali-activated slag pastes by electrical impedance spectroscopy (EIS). Constr Build Mater 261:119982.https://doi.org/10.1016/j.conbuildmat.2020.119982\u003c/li\u003e\n\u003cli\u003eZ. Liu, P. Feng, R. Liu, L. Yuan, X. Meng, G. Tao, J. Chen, Q. Ran, J. Hong, J. Liu, C. Miao (2024) Integration of zinc anode and cement: unlocking scalable energy storage. Natl Sci Rev 11.https://doi.org/10.1093/nsr/nwae309\u003c/li\u003e\n\u003cli\u003eH. Xu, S. Zhong, C. Yuan, X. Zheng, S. Wang (2024) Honeycomb-like N, S dual-doped porous carbons derived from pomelo peel by effective exogenous doping strategy for supercapacitor electrodes. Diam Relat Mater 150:111768-111768.https://doi.org/10.1016/j.diamond.2024.111768\u003c/li\u003e\n\u003cli\u003eB. Tan, H. Li, Q. Yuan, F. An (2024) Optimizing activated carbon electrodes and improving their electrochemical performance through nitrogen doping and HNO\u003csub\u003e3\u003c/sub\u003e modification. Mater Today Commun 41:110459-110459.https://doi.org/10.1016/j.mtcomm.2024.110459\u003c/li\u003e\n\u003cli\u003eJ. Li, D. Wang, F. Meng, G. Wang (2025) Nitrogen and sulfur co-doped porous carbon obtained from direct carbonization of a renewable biomass for counter electrode of efficient dye-sensitized solar cells. Mater Sci Eng B- Adv 311:117778-117778.https://doi.org/10.1016/j.mseb.2024.117778\u003c/li\u003e\n\u003cli\u003eB.A. Salami, T.A. Oyehan, A. Tanimu, A.B. Olabintan, M. Ibrahim, M.O. Sanni Anibire, S.A. Nafiu, O. Arowojolu, T.A. Saleh (2022) Cement-based batteries design and performance. A review. Environ Chem Lett 20:1-24.https://doi.org/10.1007/s10311-022-01389-x\u003c/li\u003e\n\u003cli\u003eWang, D. Zhang (2022) Structural supercapacitor constructed by SnO2/graphene coated nickel foam electrode and synchronously synthesized polymer cement electrolyte at room temperature. Mater Chem Phys 277:125488.https://doi.org/10.1016/j.matchemphys.2021.125488\u003c/li\u003e\n\u003cli\u003eS.V. Lokesh, B.S. Sherigara, Jayadev, H.M. Mahesh, R.J. Mascarenhas (2008) Electrochemical reactivity of C60 modified carbon paste electrode by physical vapor deposition method. Int J Electrochem Sc 3: 578-587.https://doi.org/10.1016/S1452-3981(23)15545-3\u003c/li\u003e\n\u003cli\u003eK.M. Metz, P.E. Colavita, K.Y. Tse, R.J. Hamers (2011) Nanotextured gold coatings on carbon nanofiber scaffolds as ultrahigh surface-area electrodes. J Power Sources 198:393-401.https://doi.org/10.1016/j.jpowsour.2011.09.098\u003c/li\u003e\n\u003cli\u003eF.D.A.D.S. Silva, M.G.A.D. Silva, P.R. Lima, M.R. Meneghetti, L.T. Kubota, M.O.F. Goulart (2013) A very low potential electrochemical detection of l-cysteine based on a glassy carbon electrode modified with multi-walled carbon nanotubes/gold nanorods. Biosens Bioelectron 50:202-209.https://doi.org/10.1016/j.bios.2013.06.036\u003c/li\u003e\n\u003cli\u003eT. Deng, J. Li, G. Zhao, Y. Fu, J. Yuan, R. Xie, H. Huang, L. Su, H. Liu (2024) Visible-light photoelectric performance and bending stability of flexible LaCoO\u003csub\u003e3\u003c/sub\u003e/Mica thin films. Ceram Int 50:27165-27175.https://doi.org/10.1016/j.ceramint.2024.05.014\u003c/li\u003e\n\u003cli\u003eJ. Wang, J. Wang, Y. Mao, R. Peng, F. Nie (2022) The surface activation of boron to improve ignition and combustion characteristic. Def Technol18:1679-1687.https://doi.org/10.1016/j.dt.2021.09.012\u003c/li\u003e\n\u003cli\u003eJ. Wang, Y. Mao, J. Chen, Z. Li, J. Wang, F. Nie (2022) Surface engineering boron/graphite fluoride composite with enhanced ignition and combustion performances. Fuel 323.https://doi.org/10.1016/j.fuel.2022.124374\u003c/li\u003e\n\u003cli\u003eJ. Wang, J. Chen, Y. Mao, Y. Deng, W. Cao, F. Nie, J. Wang (2024) Construct a 3D microsphere of HMX/B/Al/PTFE to obtain the high energy and combustion reactivity. Def Technol 32:45-54.https://doi.org/10.1016/j.dt.2023.07.016\u003c/li\u003e\n\u003cli\u003eC. Schlumberger, C. Scherdel, M. Kriesten, P. Leicht, A. Keilbach, H. Ehmann, P. Kotnik, G. Reichenauer, M. Thommes (2022) Reliable surface area determination of powders and meso/macroporous materials: Small-angle X-ray scattering and gas physisorption. Micropor Mesopor Mat 329:111554.https://doi.org/10.1016/j.micromeso.2021.111554\u003c/li\u003e\n\u003cli\u003eF. Chen, J. Wen, Y. Li, L. Liu, Y. Shi, Y. Lyu, B. Xing, J. Yang (2025) Effects of the modified expanded perlite materials on magnesium phosphate cement-based fireproof mortars: mechanical property. thermal conductivity and microstructure Case Stud Constr Mat 22:e04140.https://doi.org/10.1016/j.cscm.2024.e04140\u003c/li\u003e\n\u003cli\u003eZ. Liu, T. Huang, Y. Cao, C. Liu (2024) Permeability test and meso-structure analysis of biochar-cement soil. Rock Soil Mech 45:2929-2936.https://doi.org/10.16285/j.rsm.2023.1907\u003c/li\u003e\n\u003cli\u003eM. David, L. Zhi, Z.W. Xu, X.H. Tan, H.L. Wang, H. Chris, S. Tyler (2013) Mesoporous nitrogen-rich carbons derived from protein for ultra-high capacity battery anodes and supercapacitors. Energy Environ Sci 1:513-513.https://doi.org/10.1039/C2EE23599D\u003c/li\u003e\n\u003cli\u003eW. She, Y. Zhang, C. Miao, J. Hong, S. Mu (2019) Water transport in foam concrete: visualisation and numerical modelling. Mag Concrete Res 72:734-746.https://doi.org/10.1680/jmacr.18.00190\u003c/li\u003e\n\u003cli\u003eY. Wang, S. Zuo (2016) Electrochemical properties of phosphorus-pontaining activated carbon electrodes on electrical double-layer capacitors. Acta Phys-Chim Sin 32:481-492.https://doi.org/10.3866/PKU.WHXB201511041\u003c/li\u003e\n\u003cli\u003eT.P. Mokoena, Z.P. Tshabalala, K.T. Hillie, H.C. Swart, D.E. Motaung (2020) The blue luminescence of p-type NiO nanostructured material induced by defects: H\u003csub\u003e2\u003c/sub\u003eS gas sensing characteristics at a relatively low operating temperature, Appl Surf Sci 525: 146002.https://doi.org/10.1016/j.apsusc.2020.146002\u003c/li\u003e\n\u003cli\u003eH. Zhong, F. Xu, Z. Li, R. Fu, D. Wu (2013) High-energy supercapacitors based on hierarchical porous carbon with an ultrahigh ion-accessible surface area in ionic liquid electrolytes. Nanoscale 5:4678-4682.https://doi.org/10.1039/C3NR00738C\u003c/li\u003e\n\u003cli\u003eF. Wu, M. Zhang, Y. Bai, X. Wang, R. Dong, C. Wu (2019) Lotus seedpod-derived hard carbon with hierarchical porous structure as stable anode for sodium-ion batteries. ACS Appl Mater Interfaces, 11:12554-12561.https://doi.org/10.1021/acsami.9b01419\u003c/li\u003e\n\u003cli\u003eD. M. Sayed, M.M. Taha, L.G. Ghanem, M.S. Deab, N.K. Allam (2020) Hybrid supercapacitors: A simple electrochemical approach to determine optimum potential window and charge balance . J Power Sources 480: 229152.https://doi.org/10.1016/j.jpowsour.2020.229152\u003c/li\u003e\n\u003cli\u003eY. Qiu, J. Lu, Y. Yan, J. Niu (2022) Enhanced visible-light-driven photocatalytic degradation of tetracycline by 16% Er\u003csup\u003e3+\u003c/sup\u003e-Bi\u003csub\u003e2\u003c/sub\u003eWO\u003csub\u003e6\u003c/sub\u003e photocatalyst.J. Hazardous Mater 422:126920. https://doi.org/10.1016/j.jhazmat.2021.126920\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"ionics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":" Learn more about [Ionics](https://www.springer.com/journal/11581) ","snPcode":"11581","submissionUrl":"https://mc.manuscriptcentral.com/ionics","title":"Ionics","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Cement, Activated carbon, Electrochemical performance, Supercapacitors","lastPublishedDoi":"10.21203/rs.3.rs-6868638/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6868638/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eAs traditional energy sources continue to deplete, the development of electrodes aimed at improving energy storage has become a promising approach to mitigate the energy crisis. Additionally, the cement-based electrode possesses advantages such as low cost and easy fabrication, which contribute to its promising potential for applications in batteries, capacitors, and especially supercapacitors. However, cement-based electrode also has the disadvantages of large resistance and unclear fitting circuit, which limit its practical use. Two types of cement-based carbon-doped electrodes were prepared by blending conductive activated carbon with ordinary cement. In one approach, gold was deposited onto the electrode surface, while in another, polytetrafluoroethylene (PTFE) was used to adhere the electrode to aluminum foil. The electrode treated with PTFE-coated aluminum foil shows a lower specific capacitance of 0.045 F/cm\u0026sup2; at 10 mA/cm\u0026sup2; and a higher resistance (15.7 Ω\u0026middot;cm\u0026sup2;). However, it is surprising that the surface gold-sprayed electrode displays superior electrochemical performance, exhibiting a specific capacitance of 0.058 F/cm\u0026sup2; at 10 mA/cm\u0026sup2; and a low resistance (6.4 Ω\u0026middot;cm\u0026sup2;). More importantly, at the higher current density of 50 mA cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e, 95% of the capacitance is retained. This result provides an ideal host for the practical application of cement-based carbon-doped electrodes.\u003c/p\u003e","manuscriptTitle":"Fabrication and capacitive performance of cement-based electrode for structural supercapacitor","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-17 05:50:30","doi":"10.21203/rs.3.rs-6868638/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-06-27T15:07:24+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-27T14:21:47+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-24T01:53:33+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-23T10:47:50+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"120881609841166885442601791966961468673","date":"2025-06-13T08:48:36+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"136268316193689673854586546720640286616","date":"2025-06-13T00:44:28+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"91148457306763729782017244408784172497","date":"2025-06-12T14:28:37+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-06-12T11:23:59+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-06-11T23:39:17+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-06-11T23:38:09+00:00","index":"","fulltext":""},{"type":"submitted","content":"Ionics","date":"2025-06-11T06:45:08+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"ionics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":" Learn more about [Ionics](https://www.springer.com/journal/11581) ","snPcode":"11581","submissionUrl":"https://mc.manuscriptcentral.com/ionics","title":"Ionics","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"01948c79-e357-4cc9-a9b9-35bc564a07af","owner":[],"postedDate":"June 17th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-08-05T14:08:51+00:00","versionOfRecord":[],"versionCreatedAt":"2025-06-17 05:50:30","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6868638","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6868638","identity":"rs-6868638","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}