Spinel LiMn2O4 cathode material doped with Cr^3＋ and F- was prepared by solid-state reaction, and the material was modified by coating Al2O3 on its surface. The morphology and structure were characterized with scanning electron micrograph and X-ray diffraction, and the electrochemical properties were studied with charging-discharging test and A.C impedance test. The results showed that both materials doped with Cr^3＋ and F- and coated with Al2O3 had a spinel structure. With increasing level of doping and coating, their initial discharging cap...
