The present study used the Pechim process with a heat treatment to synthesize LiMn2O4 powder (LMO). After surface coating, a nano-sized oxidative film of Li-Ni-Mn formed on the surface of the LMO-Ni powders. The concentration of Mn3+ for the LMO-Ni powder was lower and the average electrovalence of Mn exceeded the theoretical value, resulting in the initial capacity of the LMO-Ni powder being lower than the LMO powder. However, the LMO-Ni powder with the Li/Ni film not only restrained Mn ions from dissolving into the electrolyte, but also improved the charge-discharge cycling capacity. (c) 2007 Elsevier B.V. All rights reserved.