Preparation and Electrochemical Properties of Doped Spinel Lithium Manganese Oxides

Spinel lithium manganese oxides doped with lithium, nickel and titanium were prepared by a liquid method. FT-IR, XRD and XPS were used to analyse the appearance of samples. Meantime, electrochemical properties of the materials in the organic electrolyte were researched. The results show that the materials doped with nickel and titanium have a platform in 4V region and have high first discharge capacity(140.9mAh/g), better cyclic stability than pure spinel lithium manganese oxides. The reason is that nickel and titanium ions displace part manganese ions in 16d positions and lead to the shrinkage of spinel cells and the increase of valence state of manganese, thus the structure of spinel becomes more steady and Joan-Teller effect is restrained.