Preparation and performance of Mg-doped spinel-structured LiMn2O4 cathode materials

Abstract

The main work of this paper is to use the traditional high-temperature solid-state synthesis method to synthesize lithium manganese spinel cathode material and modify it by doping under optimized process parameters to improve its cycle performance. The doping of Mg2+ reduces the content of Mn3+ in the material. The material with Mg doping has higher structural stability and inhibits the Jahn-Teller and reduces the dissolution of Mn. LiMgxMn2−xO4 (x = 0, 0.02, 0.04, 0.06, 0.08) was synthesized by the traditional high-temperature solid-state method. The crystal structure and morphology of the synthesized powders were characterized by XRD, SEM, and FT-IR, respectively. The electrochemical performance of the battery was tested by CV, EIS, and long-term cycling. Among them, LiMg0.04Mn1.96O4 had the best cycling performance, the first discharge capacity of the material was 113.5 mAh·g−1. When it was cycled to 500 cycles at 0.1 C, still had the capacity of 92 mAh·g−1 with a capacity retention rate of 81.05%.