Elevated temperature cycling stability and electrochemical impedance of LiMn2O4 cathodes with nanoporous ZrO2 and TiO2 coatings

In this study, nanoporous zirconia (ZrO2) and Mania (TiO2) coatings are shown to stabilize the cycling performance of lithium-ion batteries with Li Mn2O4 spinel cathodes. The effect of firing temperature on the coating pore size is discussed and the resulting performance of the coated cathodes is evaluated. Stabilization mechanisms, such as neutralization of acidic electrolytes by ZrO2 and TiO2 coatings, are examined. It is proposed that the establishment of a complex nanoporous network for lithium-ion transport results in a more uniform current distribution at the particle surface, thereby suppressing capacity fade that may be associated with surface instabilities of the spinel electrode. (C) 2010 Elsevier B.V. All rights reserved.