Fig. 2.
a Reaction model diagrams of the NCM622 cathode; the reaction rate at each stage is calculated and shown. b Schematic of the NCM622 cathode materials synthesis at different synthetic temperatures and holding times: Low temperature (25 ~ 700 °C; I) completed the phase transition from layered TM(OH)2 to intermediate LixNCM6221−xO; optimized temperature (700 ~ 900 °C; II) enables the formation of layered oxides with structural disordering; and holding times (~ 900 °C; III) cause particle growth and perfect layered crystal structure