Kinetics Study of the High Potential Range of Lithium-Rich Transition-Metal Oxides for Lithium-Ion Batteries by Electrochemical Methods

Lithium-rich transition-metal oxides lose oxygen during the first removal of lithium. In this study, the kinetics of the oxygen-loss process of the lithium-rich oxide, Li [ Li 1 / 9 Ni 1 / 3 Mn 5 / 9 ] O 2 , of varying particle sizes was studied. The electrochemical data were analyzed, and oxygen diffusion constants of 3 × 10 − 13 and 2 × 10 − 12 cm 2 s − 1 were determined for the oxygen-loss process at 30 and 55 ° C , respectively. This is about 1000 times smaller than typical lithium diffusion constants in layered oxides. The Li [ Li 1 / 9 Ni 1 / 3 Mn 5 / 9 ] O 2 material with a 3 μ m particle size was cycled without capacity loss at a specific capacity of 240 mAh g − 1 at 55 ° C .