Preparation and electrochemical properties of spinel LiMn2O4 prepared by solid-state combustion synthesis

Abstract

Spinel LiMn2O4 cathode material was rapidly prepared by solid-state combustion synthesis based on a two-stage calcination progress which used lithium carbonate and manganese carbonate as raw materials and citric acid as a fuel. The structure and physicochemical properties of the obtained LiMn2O4 powders were investigated by thermogravimetric analysis (TG) and differential thermal analysis (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), galvanostatic charge–discharge test, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results show that the successful formation of single-phase LiMn2O4 product is highly dependent on its second-stage calcination temperature. Compared with other conditions, the as-prepared LiMn2O4 powders which experienced the second-stage, and calcined at 700 °C is the most uniform, and the charge transfer resistance (Rct) is the lowest, accompanying the best electrochemical activity and highest discharge capacity. Its initial discharge specific capacity is 119.1 mA h/g.