Surface modification by ZnO coating for improving the elevated temperature performance of LiMn2O4

ZnO was used to the surface modification of LiMn2O4 by sol-gel method to improve the elevated temperature performance of LiMn2O4. The electrochemical performance of the uncoated and ZnO-coated LiMn2O4 were investigated under a current rate of C/2 at 55 degrees C, between 3.4 V and 4.3 V. While the uncoated LiMn2O4 delivered an average capacity loss of 0.81% per cycle in 50 cycles, the I wt.%, 2 wt.% and 5 wt.% ZnO-coated LiMn2O4 only showed the average capacity loss of 0.54%, 0.19% and 0.14% per cycle, respectively. XRD results of the cathode materials after 50 cycles at 55 degrees C revealed that ZnO coating could effectively suppress the dissolving of LiMn2O4 into electrolyte and resulted in a better stability. (C) 2006 Elsevier B.V. All rights reserved.