Enhanced high-rate cycling stability of LiMn2O4 cathode by ZrO2 coating for Li-ion battery

The effect of a sol-gel derived amorphous zirconium oxide surface coating on the high charge-discharge (CD) rate performance of LiMn2O4 was studied. When cycled between 4.5 and 2.9 V (vs. Li/Li+) at room temperature, the coated spinel electrode, containing 5 wt %-ZrO2, shows tremendous enhancement in cycling stability at CD rates up to 10 C. Concurrently, the coated spinel electrode exhibits a lower cubic-tetragonal transition potential, a smaller charge-transfer impedance by 4-5-fold, and it profoundly reduces, by 66%, lattice contraction upon charge (delithiation). The enhancement in the high-rate cycling stability has been attributed to the combination of these favorable effects. (c) 2005 The Electrochemical Society. [DOI: 10.1149/1.1945727] All rights reserved.