Surface oxygen drives electrolyte degradation at Ni-rich battery cathodes

Surface oxygen drives electrolyte degradation at Ni-rich battery cathodes | 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 Article Surface oxygen drives electrolyte degradation at Ni-rich battery cathodes Ifan Stephens, Daisy Thornton, Ieuan Seymour, Zonghao Shen, Wesley Dose, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6512009/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The rapid uptake of lithium-ion batteries for large scale electric vehicle and energy storage applications requires a deeper understanding of the degradation mechanisms that contribute to fading performance. Capacity fade arises because of complex and interlinking degradation mechanisms such as phase transitions, electrolyte decomposition and transition metal dissolution. These degradation reactions are still poorly understood; however, many of them evolve gases as a side product. Here we present detection of gaseous species evolving from operating lithium-ion batteries with chip-based electrochemistry mass spectrometry. We observe oxygen (O2) evolution from a Li(Ni0.8Mn0.1Co0.1)O2 (NMC811) cathode, and electrolyte solvent degradation to CO2 and CO. We study isotopically labelled NMC to monitor where lattice oxygen is incorporated into electrolyte oxidation products. A previously unobserved deleterious catalytic CO oxidation mechanism is identified as we provide the first direct evidence that lattice oxygen loss is coupled to electrolyte decomposition on the oxide surface, rather than by reactive oxygen species. We also report a difference in electrolyte decomposition onset potential and quantify the extent of lattice oxygen loss between EC containing and EC-free electrolytes. The ensuing understanding of the newly identified and deconvoluted degradation mechanisms will facilitate the development of longer lasting lithium-ion batteries, as well as facilitate the development of more accurate battery lifetime models. Physical sciences/Chemistry/Electrochemistry/Batteries Physical sciences/Chemistry/Energy Full Text Additional Declarations There is NO Competing Interest. None Supplementary Files ElectrolytedrivenOlossSI.pdf Cite Share Download PDF Status: Posted Version 1 posted 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. 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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-6512009","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":456284934,"identity":"24a88a2e-88ff-4b2d-9460-8be79f9e9069","order_by":0,"name":"Ifan Stephens","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABFklEQVRIiWNgGAWjYBACNgh1AIiZDxyAiDA3gMUkcGthbIBoYUuAamHEr4UBoYXHAEkAjxY+BvbnDz7uuCNnzn/m46GbO2zy+dgPNjD8qGFInNmAy2E8ho0zzzwztpyRu+Fw7pk0yzaexAbGnmMMibNx+oWHsZm37XDihhu8QC1thw3YGBIbGHgbGBLn4dTC/rD5b9vh+g3nzzwAavlvwMb/sIHxL14tDIbNjG2HEwwO5DAAtRwwYJNIbGAG2YLTYcw8hjN7zxw23HAjzQDol2SglocNh2WOSRjj8r58e/uDDz93HJY3OH/48efcHXYG8v3JBx++qbGRnXEAhzXMDPCIQDAO4I1IZJUIxigYBaNgFIwCJAAAJm9h/bXk6Z0AAAAASUVORK5CYII=","orcid":"https://orcid.org/0000-0003-2157-492X","institution":"Imperial College","correspondingAuthor":true,"prefix":"","firstName":"Ifan","middleName":"","lastName":"Stephens","suffix":""},{"id":456284935,"identity":"6cdfe546-e0ad-4219-a19e-df970c587132","order_by":1,"name":"Daisy Thornton","email":"","orcid":"","institution":"Imperial College London","correspondingAuthor":false,"prefix":"","firstName":"Daisy","middleName":"","lastName":"Thornton","suffix":""},{"id":456284936,"identity":"1fc0de2f-3f85-410b-b964-7dfaba79c3bc","order_by":2,"name":"Ieuan Seymour","email":"","orcid":"","institution":"Aberdeen University","correspondingAuthor":false,"prefix":"","firstName":"Ieuan","middleName":"","lastName":"Seymour","suffix":""},{"id":456284937,"identity":"804ead00-4df4-48fa-bb6d-6dcc730a189b","order_by":3,"name":"Zonghao Shen","email":"","orcid":"","institution":"Grenoble","correspondingAuthor":false,"prefix":"","firstName":"Zonghao","middleName":"","lastName":"Shen","suffix":""},{"id":456284938,"identity":"68ea051b-f9b1-41d3-a42f-1f7ebba68d0f","order_by":4,"name":"Wesley Dose","email":"","orcid":"https://orcid.org/0000-0003-3850-0505","institution":"University of Sydney","correspondingAuthor":false,"prefix":"","firstName":"Wesley","middleName":"","lastName":"Dose","suffix":""},{"id":456284939,"identity":"d679d2ed-c9d6-497a-9181-ab810ebed911","order_by":5,"name":"Ainara Aguadero","email":"","orcid":"","institution":"CSIC","correspondingAuthor":false,"prefix":"","firstName":"Ainara","middleName":"","lastName":"Aguadero","suffix":""},{"id":456284940,"identity":"98e9f7f8-e5ac-4a00-abbd-0d3ab7aed7ec","order_by":6,"name":"Clare Grey","email":"","orcid":"https://orcid.org/0000-0001-5572-192X","institution":"[email protected]","correspondingAuthor":false,"prefix":"","firstName":"Clare","middleName":"","lastName":"Grey","suffix":""},{"id":456284941,"identity":"180fba28-993f-41f9-abc6-eda3c8137fdb","order_by":7,"name":"Michael F.L. 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Capacity fade arises because of complex and interlinking degradation\r\nmechanisms such as phase transitions, electrolyte decomposition and transition metal\r\ndissolution. These degradation reactions are still poorly understood; however, many of them\r\nevolve gases as a side product. Here we present detection of gaseous species evolving from\r\noperating lithium-ion batteries with chip-based electrochemistry mass spectrometry. We observe\r\noxygen (O2) evolution from a Li(Ni0.8Mn0.1Co0.1)O2 (NMC811) cathode, and electrolyte solvent\r\ndegradation to CO2 and CO. We study isotopically labelled NMC to monitor where lattice oxygen\r\nis incorporated into electrolyte oxidation products. A previously unobserved deleterious catalytic\r\nCO oxidation mechanism is identified as we provide the first direct evidence that lattice oxygen\r\nloss is coupled to electrolyte decomposition on the oxide surface, rather than by reactive oxygen\r\nspecies. We also report a difference in electrolyte decomposition onset potential and quantify the\r\nextent of lattice oxygen loss between EC containing and EC-free electrolytes. The ensuing\r\nunderstanding of the newly identified and deconvoluted degradation mechanisms will facilitate\r\nthe development of longer lasting lithium-ion batteries, as well as facilitate the development of\r\nmore accurate battery lifetime models.","manuscriptTitle":"Surface oxygen drives electrolyte degradation at Ni-rich battery cathodes","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-15 07:17:28","doi":"10.21203/rs.3.rs-6512009/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"39aef963-8876-4123-b399-426d9b265984","owner":[],"postedDate":"May 15th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":48499444,"name":"Physical sciences/Chemistry/Electrochemistry/Batteries"},{"id":48499445,"name":"Physical sciences/Chemistry/Energy"}],"tags":[],"updatedAt":"2025-07-31T20:50:17+00:00","versionOfRecord":[],"versionCreatedAt":"2025-05-15 07:17:28","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6512009","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6512009","identity":"rs-6512009","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}