Impact of the Li-loss mechanisms inherent to the physical vapor deposition of LiCoO2 cathode on its electrochemical performance
GPa-resistant conformal LiCoO2 cathodes grown by physical vapor deposition (PVD), with negative chemical expansion coefficients, are promising systems for mechanically stabilizing cathode/solid electrolyte interfaces in solid-state lithium-ion batteries. However, exploiting its potential preliminari...
| Autores: | , , , , , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2024 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/388324 |
| Acesso em linha: | http://hdl.handle.net/10261/388324 https://api.elsevier.com/content/abstract/scopus_id/85199328189 |
| Access Level: | acceso abierto |
| Palavra-chave: | Energy materials Li stoichiometry by physical vapor deposition Thin film cathodes |
| Resumo: | GPa-resistant conformal LiCoO2 cathodes grown by physical vapor deposition (PVD), with negative chemical expansion coefficients, are promising systems for mechanically stabilizing cathode/solid electrolyte interfaces in solid-state lithium-ion batteries. However, exploiting its potential preliminarily requires that we are able to control the reversibility of Li stoichiometry under PVD conditions, which represents a major challenge since metal Li is lightweight, volatile and has high diffusivity. By combining different chemical and structural analysis techniques, we identify the mechanisms of Li loss by PVD and demonstrate that unlike the electrochemical delithiation of LiCoO2, the crystallization of LiCoO2 admits only a small amount of Li vacancies, so that in a Li-deficient regime, segregated phases of fully stoichiometric LiCoO2 and Li-free Co oxides are formed. From the laterally- and depth-resolved concentrations of the coexisting phases, we can conclude that PVD-grown LiCoO2 is partially stabilized into morphological features with reduced specific surface areas (i.e., large isotropic faceted grains and thick films), resulting in an improvement of its specific electrochemical properties and performance. |
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