Preparation and electrochemical properties of LiMn1.95M0.05O4 (M = Cr, Ni)

The preparation process and electrochemical properties of LiMn2O4 and LiMn1.95M0.05O4 (M = Cr, Ni) were studied. The results show that the decomposition temperature range of xerogel prepared with lithium acetate and manganese acetate as raw materials is large and the decomposition speed is slow. Oxygen consumed is apt to get a prompt supplement during the preparation of LiMn2O4, and carbonization of the organic matter can be reduced or avoided, which is favorable to the combination of lithium and manganese. Using lithium acetate, manganese acetate, chromium nitrate, and nickel nitrate as raw materials and adopting the citric acid complexing method, it has been found that the prepared powders have high purity, high quality stability, and even doping characters. With the increase of sintering temperature, the particle size and crystal lattice constant of LiMn1.95M0.05O4 (M = Cr, Ni) enhance. However, the purity of the product is relatively high and has no obvious change, which is advantageous to the control of the quality of LiMn1.95M0.05O4 (M = Cr, Ni). Doping with a small amount of Cr3+ and Ni2+ can stabilize the spinel structure of LiMn2O4, suppress the Jahn-Teller effect, and improve the cycling properties but reduce the initial capacity.