Effect of La doping on the structure and electrochemical properties of layered Li-rich Mn-based oxide cathode materials

La doping Li_1.2Mn_0.54-xNi_0.13Co_0.13La_xO₂(x=0, 0.01, 0.03, 0.05) layered Li-rich Mn-based oxide cathode materials were prepared by carbonate coprecipitation-high temperature sintering method. The effect of La doping on the structure and electrochemical properties of cathode materials was investigated. The structures and morphologies of cathode materials were analyzed by the X-ray diffraction (XRD) and scanning electron microscopy (SEM), electrochemical properties of materials were tested by AC Impedance and Charge and Discharge Tester. The results show that layered α-NaFeO₂ structure is maintained in all samples, and the morphology of samples does not change obviously with the increase of La doping amount. However, the discharge capacity of samples increases first and then decreases. They obtain the highest discharge specific capacity of 285.3 mAh/g (0.1 C) when the doping amount of La is 0.03. The specific discharge capacity is 260.5 mAh/g after 50 cycles and the capacity retention ratio is 91.3 %.