Precursor pre-oxidation enables highly exposed plane {010} for high-rate Li-rich layered oxide cathode materials

Abstract

Precursor synthesis technology is a key factor to improve the electrochemical properties of Li-rich layered oxide (LLO) cathode materials. However, the effect of precursor preparation strategies on the morphology and electrochemical properties of cathode materials has not been clearly elucidated. In this work, an LLO cathode material (denoted as LMNC-300) with highly exposed {010} planes and a lower amount of surface residual lithium is reported via pre-oxidation of a precursor at 300 °C. This LMNC-300 cathode material exhibits an initial Coulombic efficiency of 91.7% with a discharge capacity of 277.2 mA h g−1 at 0.1 C, an excellent high-rate capability with a discharge capacity of 175.1 mA h g−1 even at 5.0 C and a good cycling performance with a capacity retention of 92.6% after 200 cycles at 0.5 C. In addition, a pouch cell consisted of the LMNC-300 cathode and a commercial graphite anode presented good cycling stability with a capacity retention of 81.6% after 500 cycles at 2.0 C. The outstanding electrochemical performance can be ascribed to an accelerated Li+ diffusion dynamics. Therefore, the method reported in this work will be significant to understanding the effects of preparation strategies of transition metal precursors on the electrochemical performance of Li-rich layered cathode materials for high-energy density Li-ion batteries.