Electrochemical characterizations of surface modified LiMn 2O 4 cathode materials for high temperature lithium battery applications

Abstract

LiMn 2O 4 spinel cathode materials were coated with 2.0 wt.% of La 2O 3 by polymeric process followed by calcinations at 400 °C and 800 °C for 6 h in air. The surface coated LiMn 2O 4 cathode materials were physically characterized using X-ray diffraction, Scanning electron microscopy, Transmission electron microscopy and X-ray photoelectron spectroscopy. La 2O 3-coated LiMn 2O 4 coating did not affect the crystal structure and space group Fd3m of the cathode materials compared to the uncoated LiMn 2O 4. The surface morphology and particle agglomeration were investigated and compact coating layer on the surface of the core materials. La 2O 3 was completely coated over the surface of the LiMn 2O 4 core cathode materials. The galvanostatic charge and discharge of the La 2O 3-coated LiMn 2O 4 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, La 2O 3-coated spinel LiMn 2O 4 cathode at 800 °C has improved the structural stability, high reversible capacity and excellent electrochemical performances of the rechargeable lithium batteries.