Synthesis and electrochemical studies of spinel LiNi1-xMnxVO4

Spinel compound LiNi1-xMnxVO4 (0 less than or equal to x less than or equal to 0.4) had been prepared by using the moist chemical method. X-ray diffraction spectra showed that the lattice constant increased with x in the LiNi1-xMnxVO4, XPS spectra indicating that Li1s had a chemical shift towards lesser binding energy, and manganese in LiNi1-xMnxVO4 existing as the mixed valence of Mn2+ and Mn3+. The electrochemical charge and discharge testing at a current density of 0.1 mA/cm(2) between the potentials of 4.0 and 3.0 V vs Li/Li+ in 1 mol/dm(3) LiPF6/EC+DEC (1:1 by volume) at 25degreesC showed that LiNi1-xMnxVO4 cell has a better rechargeability, but a lower cell voltage of 4.0 V vs Li/Li+ than that without the doping sample, and the capacity and the cycle efficiency of the Li/LiNi1-xMnxVO4 cells increased with x in the LiNi1-xMnxVO4. (C) 2002 Elsevier Science (USA).