Synthesis and Electrochemical Performances of Spinel LiMn2-xInxO4 (x=0, 0.01, 0.02, 0.05)

The spinel LiMn2-xInxO4 (x=0, 0.01, 0.02, 0.05) cathode materials were prepared by a citric acid-assisted sol-gel method using LiOH, Mn (CH3COO)(2) and In2O3 as raw materials and citric acid as the chelating agent. The resultant materials were characterized by XRD and SEM for the structure and morphology, respectively. The electrochemical properties of the materials were investigated by galvanostatic charge and discharge, CV and EIS test. The influence of different indium dopant concentration on the electrochemical properties of LiMn2-xInxO4 cathode materials was examined. The results revealed that the LiMn1.99In0.01O4 sample exhibits the pure cubic spinel phase structure without impurity. And the initial discharge capacity of LiMn1.99In0.01O4 was 119.9 mAh.g(-1) at 0.5C and 3.4 similar to 4.35 V range, it remained 84.9% of the initial specific discharge capacity after 0.5C by 30 cycles,1C by 30 cycles, 2C by 30 cycles, and 0.5C by 5 cycles again. The LiMn1.99In0.01O4 displayed better electrochemical performance. Compared with the parent LiMn2O4, the cyclic performance of LiMn1.99In0.01O4 cathode material at elevated temperature was more excellent than the undoped LiMO2O4.