Effects of chromium doping on performance of LiNi0.5Mn1.5O4 cathode material

In order to improve the cycle and rate performance of LiNi0.5Mn1.5O4, LiCr2YNi0.5–YMn1.5–YO4 (0≤Y≤0.15) particles were synthesized by the sucrose-aided combustion method. The effects of Cr doping in LiNi0.5Mn1.5O4 on the structures and electrochemical properties were investigated. The samples were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), galvanostatic charge-discharge test and electrochemical impedance spectrum (EIS). The results indicate that the LiCr2YNi0.5–YMn1.5–YO4 possess a spinel structure and small particle size, and LiCr0.2Ni0.4Mn1.4O4 exhibits the best cyclic and rate performance. It can deliver discharge capacities of 143 and 104 mA·h/g at 1C and 10C, respectively, with good capacity retention of 96.5% at 1C after 50 cycles.