resumo
Transport properties of Li+ mobile ions in fresh and aged LiMn2O4 battery cathodes were studied at the nanoscale via electrochemical strain microscopy (ESM), time spectroscopy, and voltage spectroscopy mapping. Both Vegard and plausible non-Vegard contributions to the ESM signal were identified in electrochemical hysteresis loops obtained on fresh and aged samples. In the fresh cathodes, the Vegard contribution dominates the signal, while in the aged samples different shape of hysteresis loops indicates an additional plausible non-Vegard contribution. Non-uniform spatial distribution of the electrochemical loop opening in LiMn2O4 particles studied in the aged samples indicates stronger variation of the Li diffusion coefficient at the microscale as compared to the fresh specimens. Time spectroscopy measurements revealed a suppression of the local Li diffusivity in aged samples. The mechanisms of the cathode aging are discussed in the context of observed nanoscale ESM response. (C) 2015 AIP Publishing LLC.
palavras-chave
LITHIUM-ION BATTERIES; NANOMETER RESOLUTION; ELECTRONIC-STRUCTURE; SPINEL; DIFFUSION; STOICHIOMETRY; SPECTROSCOPY; TEMPERATURE; MANGANITES; CONDUCTION
categoria
Physics
autores
Luchkin, SY; Romanyuk, K; Ivanov, M; Kholkin, AL
nossos autores
Andrei Kholkin
Investigador Principal
Konstantin Nikolaevich Romanyuk
Investigador Júnior
Maxim Ivanov
Investigador Júnior
Sergey Luchkin
Estudante de doutoramentoagradecimentos
The work was supported by the European Commission within FP7 Marie Curie Initial Training Network