Strategies to curb structural changes of lithium/transition metal oxide cathode materials & the changes’ effects on thermal & cycling stability

Yu Xiqian, Hu Enyuan, Bak Seongmin, Zhou Yong-Ning, Yang Xiao-Qing^†,

Time-resolved (TR) XRD patterns of overcharged (a) Li_0.33Ni_0.8Co_0.15Al_0.05O₂and (b) Li_0.33Ni_1/3Co_1/3Mn_1/3O₂during heating to 600 °C. The overcharged cathode samples sealed in quartz capillaries were heated from 25 °C to 600 °C for 4 h during the TR-XRD measurement (heating rate = 2.4 °C·min⁻¹). The subscripts R, S, and RS denote rhombohedral, spinel, and rock-salt structures, respectively. The subscript O1 represents CdI₂-typeMO₂(M= Ni, Co Mn) structure.^[32]