Partial Modification Strategies of NASICON-Type Na₃V₂(PO₄)₃ Materials for Cathodes of Sodium-Ion Batteries: Progress and Perspectives

Sodium-ion batteries (SIBs) are regarded as an important substitute for lithium-ion batteries (LIBs) due to their abundant and widespread raw material resources. The choice of the cathode has a great influence on the electrochemical performance of the battery, and Na₃V₂(PO₄)₃ (NVP) is one of the most promising cathodes for SIBs. Its special NASICON (Na superionic conductor) three-dimensional structure is conducive to achieving excellent structural and thermal stability during the charging and discharging process. Moreover, it has a flat sodiation/desodiation potential plateau and rapid sodium diffusion kinetics. However, the weak intrinsic conductivity limits its further application in the market. Fortunately, there are some strategies, like doping foreign ions, modifying the carbon coating, constructing NVP-based heterogeneous composite materials, and changing the morphology of NVP particles, that are powerful approaches to solve this problem. Herein, the structure and some modification strategies (i.e., foreign ion doping, carbon coating, and construction of NVP-based heterogeneous composite materials) of NVP are carefully reviewed. Finally, we summarized this paper and explored the future development of the NVP cathode.