Ultrathin crystalline ZrO(2) nanofilms have been facilely deposited on LiMn(2)O(4) particles at 120 °C using atomic layer deposition. The ZrO(2) coating shows high crystallinity, conformality and homogeneity, which contribute to considerably improved electrochemical performance of LiMn(2)O(4) at elevated temperature in lithium-ion batteries.