Surface modification of hierarchical Li1.2Mn0.56Ni0.16Co0.08O2 with melting impregnation method for lithium-ion batteries

Abstract Layered Li-rich oxide material Li1.2Mn0.56Ni0.16Co0.08O2 (LRM) has been studied intensively by virtue of its high discharge capacity. Nevertheless, the inferior cycle stability and rate capability issues hinder its application for electrified vehicles (EVs). Here, the CeO2-modified LRM was synthesized via an ultrafast microwave solvothermal method following by a low temperature melting impregnation method. It is not only convenient and fast, but also reducing the surface eroding which is caused by larger amount of water in traditional coating processes. The modified LRM shows an improved cycling performance that the specific discharge capacity is 168.2 mA h g−1 with the capacity retention of 86.7% at 200 mA g−1 after 100 cycles. Even current up to 5 A g−1, it also displays a high discharge capacity of 66.4 mA h g−1 with a superior capacity retention of 85.9% (based on the reversible capacity of the fifth cycle) after 300 cycles. This work demonstrates that the low temperature melting impregnation method is less surface destructive and promising to obtain surface modified LRM as cathode material for the high-energy LIBs.