Effect of LiNi1/2Mn1/2O2 coating on the electrochemical performance of Li–Mn spinel

Lithium nickel manganese oxide (LiNi1/2Mn1/2O2) was coated on spinel lithium manganese oxide (LiMn2O4) by a sol–gel process in an attempt to improve the high temperature cycling performance. The ratio of the coating sol to LiMn2O4 was adjusted to determine the relationship between the coating thickness and electrochemical performance. The crystal structure and morphology of the samples were examined by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The charge and discharge characteristics, including cyclability and electrochemical properties of the bare and the coated LiMn2O4, were measured and compared. The results showed that a LiNi1/2Mn1/2O2 coating on LiMn2O4 improves the rate capability at room temperature, and the cyclability at high temperatures.