Preparation and properties of modified aqueous sodium-ion electrode material Na₃: V₂ (PO₄)₃

Na3V2(PO4)(3)(NVP) in aqueous sodium-ion batteries cathode material was prepared by hydrothermal method and doped with non-metallic N and metal ions Al and Mn to improve the electrochemical performance of NVP. The effects of doping amount on the performance modification of NVP were investigated. When the doping amount of Mn is 0.08 mol, the samples have an obvious layered structure and show the best discharge specific capacity of 439.8 F/g. The structure and morphology of NVP were characterized by XRD, SEM, BET and XPS, and the electrochemical performance of the sample was analyzed by cyclic voltammetry and charge and discharge test. The results show that all the samples are pure NVP, and ion doping does not change the crystal structure of NVP. Al doping improves the dispersion of particles, and N, Mn doping forms obvious layered structure. The discharge specific capacity of NVP is 342 F/g, and 380.8, 405, 439.8 F/g for NVP/N, NVP/Al, NVP/Mn, at a current rate of 1 A/g. Thus, it can be seen that doping with appropriate amounts of metal ions and non-metal elements can significantly improve the aqueous electrochemical performance of NVP.