Synthesis and electrochemical properties of LiMnPO4-modified Li[Li0.2Mn0.534Co0.133Ni0.133]O2 cathode material for Li-ion batteries

Abstract

Li-rich layered oxides with high specific capacity are considered as the next generation cathode materials for advanced Li-ion batteries. However, the large initial irreversible capacity loss, inferior cycling stability and fast voltage decay still remain to be overcome before large-scale practical applications. In this work, inspired by LiMnPO4 with superior thermal and chemical stabilities and high redox potential, we design and fabricate a series of LMnPO4-modified Li[Li0.2Mn0.534Co0.133Ni0.133]O2 composites. Among them, Li[Li0.2Mn0.534Co0.133Ni0.133]O2 modified with 5wt.% LiMnPO4 (LMP5-LMCN) sample presents remarkable electrochemical properties with high initial discharge capacity of 292mAhg−1 and good capacity retention of 78.65% after 100 cycles at current density of 30mAg−1. The effects of LiMnPO4 as the surface modification layer on the electrochemical performance of Li[Li0.2Mn0.534Co0.133Ni0.133]O2 are systematically investigated. Our results demonstrate that the appropriate LiMnPO4 surface modification could not only enhance the structural stability, but also greatly suppress the voltage fading, which is beneficial to improve the cycling stability and rate capability of Li-rich layered oxides.