Improving the Electrochemical Performance of LiNi1/3Co1/3Mn1/3O2 Cathode Material by LiF Modification

Abstract

LiNi1/3Co1/3Mn1/3O2 is a widely used commercial cathode material in the fields of consumer electronics and electric vehicles. However, its energy density still falls short of the standard and needs to be improved. The most effective method is to increase the cut-off voltage, but this will result in a drop in capacity. In this study, a LiF layer is coated on the surface of LiNi1/3Co1/3Mn1/3O2 via an in situ method. It is found that the LiF layer may protect materials from side reactions with electrolytes, improve the interfacial stability, and enhance the cyclic performance. The bare sample shows relatively poor cycling stability, with capacity retention rates of 65.9% (0.2 C) and 12.8% (5 C) after 100 cycles, while 1% LiF-coated NCM has higher cycling stability with capacity retention rates of 83.4% (0.2 C) and 73.3% (5 C) after 100 cycles, respectively. Our findings suggest that a LiF surface layer could be a useful means of boosting the electrochemical performance of NCM cathode materials.