Electrochemical properties of LiNi0.5Mn1.5O4 cathode after Cr doping

The structure and electrochemical properties of Cr doped LiNi0.5−xMn1.5CrxO4 cathodes with different Cr contents (x = 0.00, 0.01, 0.03, and 0.05) were investigated by X-ray diffraction, SEM, cyclic voltammetry, charge–discharge tests, and thermogravimetric analysis. In particular, restoration of Li in the cathode during intercalation was carefully analyzed by employing heating-cooling cycles of thermogravimetric technique. Results showed that the initial discharge capacity and capacity retention of the LiNi0.5−xMn1.5CrxO4 cathode were improved as the Cr content was increased. Thermal analysis and CV test results suggested that the improvement of the electrochemical properties of the Cr doped LiNi0.5−xMn1.5CrxO4 cathode was attributed to the high oxygen affinity of the Cr, which reduced oxygen deficiency and improved structural stability of the cathode.