Electrochemical characterizations of surface modified LiMn2O4 cathode materials for high temperature lithium battery applications

LiMn2O4 spinel cathode materials were coated with 2.0 wt.% of La2O3 by polymeric process followed by calcinations at 400 °C and 800 °C for 6 h in air. The surface coated LiMn2O4 cathode materials were physically characterized using X-ray diffraction, Scanning electron microscopy, Transmission electron microscopy and X-ray photoelectron spectroscopy. La2O3-coated LiMn2O4 coating did not affect the crystal structure and space group Fd3m of the cathode materials compared to the uncoated LiMn2O4. The surface morphology and particle agglomeration were investigated and compact coating layer on the surface of the core materials. La2O3 was completely coated over the surface of the LiMn2O4 core cathode materials. The galvanostatic charge and discharge of the La2O3-coated LiMn2O4 cathode materials were carried out at 0.1 mA/g in the range of 3.0 and 4.5 V at 30 °C and 60 °C. Based on the results, La2O3-coated spinel LiMn2O4 cathode at 800 °C has improved the structural stability, high reversible capacity and excellent electrochemical performances of the rechargeable lithium batteries.