Improve the Midpoint Voltage and Structural Stability of Li-Rich Manganese-Based Cathode Material by Increasing the Nickel Content

Abstract

Lithium-rich manganese is a promising new-generation cathode material for lithium-ion batteries. However, it has the common problems of serious discharge capacity decline, poor rate performance, and faster midpoint voltage decay. In this experiment, a sol-gel method was used to synthesize a high-nickel, lithium-rich layered oxide (1 − x)Li1.2Mn0.54Co0.13Ni0.13O2 − xLiNiO2 (x = 0, 1.0, 2.0, 3.0 and 4.0) that was characterized by XRD, SEM, XPS, TEM, and charge-discharge performance tests. The research results show that increasing Ni content can improve the stability of the material structure and enhance the electrochemical performance of the cathode material. When the LiNiO2 is 0.3, the electrochemical performance is better, the capacity retention rate is 100.3% after 60 cycles at a current density of 0.2 C, and the capacity retention rate for 100 cycles at 0.5 C is 99.0%.