Reversible Energy Storage in Layered Copper-Based Coordination Polymers: Unveiling the Influence of the Ligand's Functional Group on Their Electrochemical Properties

Coordination polymers represent a suitable model to study redox mechanisms in materials where both metal cation and ligand undergo electrochemical reactions and are capable to proceed through reversible multielectron-transfer processes with insertion of cation and anion into their open structures. Designing new coordination polymers for electrochemical energy storage with improved performance relays also on the understanding of their structure-properties relationship. Here, we present a family of copper-based coordination polymer with hexafunctionalized benzene ligands forming a kagome-type layered structure, where the influence of the functional groups in their structure and electrochemical properties is investigated. Their chemical and structural properties have been explored by means of PXRD, and FTIR and Raman spectroscopies, followed by investigation of their electrochemical performance in Li half-cells by CV and galvanostatic cycling techniques. Ex-situ PXRD, Raman, XPS and ToF-SIMS measurements of cycled electrodes have been carried out providing insights into the redox mechanism of these copper-based coordination polymers as positive electrode materials.