Effects of CeO2 coating uniformity on high temperature cycle life performance of LiMn2O4

CeO2 is coated using different precipitants on the surface of LiMn2O4 in order to investigate the effect of CeO2 coating uniformity on the cycle life performance at high temperature. CeO2 is prepared by a precipitation method without the use of a surfactant. Ammonium carbonate or ammonium hydroxide is respectively used as a precipitant in order to control the morphology and particle size of CeO2. More uniform coating layer composed of well dispersed CeO2 nanoparticles is obtained with ammonium hydroxide while aggregation lead to non-uniform coating layer when ammonium carbonate is used. The CeO2-coated Limn(2)O(4) shows better cyclability both at room temperature and 60 degrees C than the pristine sample but much higher capacity retention rate can be achieved by using ammonium hydroxide. The smaller particle size and uniform coating layer obtained using ammonium hydroxide appear to contribute to the better cycling performance. (C) 2011 Elsevier B.V. All rights reserved.