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 °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 1 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 °C revealed that ZnO coating could effectively suppress the dissolving of LiMn2O4 into electrolyte and resulted in a better stability.