Structural and Electrochemical Characterization of LiMn_(2-2x)Li_xNi_xO_4 (0≤x≤0.1) Cathode Materials

Lithium and nickel co-doped LiMn2-2xLixNixO4 cathode materials (x= 0, 0.03, 0.05, 0.075, 0.1) were synthesized by a high temperature solid-state reaction route. The microstructures and morphologies of the samples were characterized by X-ray powder diffraction, X-ray absorption fine structure analysis and field emitted scanning electronic microscopy. The bond lengths of the MnO6 octahedrons and the electrochemical performances in both room temperature and elevated temperature (55℃) were characterized and discussed in comparison with LiMn2O4 spinel. The result reveals that LiMn2-2xLixNixO4 samples have a good reversibility. It is suggested that the co-doping of lithium and nickel in LiMn2O4-based compounds could stabilize the spinel structure and improve the capacity retention of the cathode materials.