Enhancing reversibility of LiNi_0.5Mn_1.5O₄ by regulating surface oxygen deficiency

Oxygen deficiency has crucial effects on the crystal structure and electrochemical performance of spinel oxide lithium electrode materials such as LiNi0.5Mn1.5O4 (LNMO) cathode. In particular, oxygen stoichiometry surface differs from that interior in LNMO. The detection local loss LNMO its correlation with cycling stability remain challenging. this study, effect controlled by sintering temperature is comprehensively investigated. high concentration vacancies segregates at regions forming a thin rock-salt and/or deficient layer. atomic-level reconstruction was demonstrated annular dark-field bright-field techniques. For synthesis LNMO, higher results crystallinity but would increase thermal cathodes while content decrease structural Therefore, sintered medium 850°C achieved best capacity retention. suggest competitive function mechanism between