The research of electrochemical performance of Mg-doped NaNi_1/3Mn_1/3Fe_1/3O₂ positive electrode materials

Abstract The demand for Li-ion batteries is increasing year by year, which poses a great challenge to the scarce Li and Co resources. Na-ion batteries are considered to be one of the potential energy storage batteries because of their low raw material cost, wide source of sodium resources, and prices that are not susceptible to market fluctuations. The layered oxide positive electrode (such as NaNi 1/3 Mn 1/3 Fe 1/3 O 2 , NMF) is a potential replacement due to its high-capacity characteristics and low-cost advantages. However, the rate performance of NMF is compromised by the slow migration kinetics of Na + ions. Here, we used the Mg doping strategy to realize the enhancement of the rates and cycling properties of NMF. Our research shows that the 2% Mg-doped cathode material has superior rate performance and cycling performance. The discharge-specific capacities are 120.5 mAh/g at 0.1C and 88.9 mAh/g for 100 cycles at 0.5C with a high retention rate (85.2%).