Cost-Effective Na₄Fe₃(PO₄)₂P₂O₇ Cathode Materials for Sodium-Ion Batteries in Large-Scale Energy Storage Applications

The rising interest in sodium-ion batteries (SIBs) has led to significant research on cathode materials, given their essential function in SIBs. Among various cathode materials, Na₄Fe₃(PO₄)₂P₂O₇ (NFPP) stands out with its NASICON structure, offering high structural stability, rapid ion transport, and high operating potential. With its ultralong cycle life, cost-effectiveness, high safety, and superb temperature adaptability, NFPP is an attractive choice for large-scale energy storage. Despite these advantages, the widespread application of NFPP is limited by low electronic conductivity and impurity issues. In this review, we discussed the crystal structure, properties, and diverse synthetic approaches of NFPP. Additionally, various modification strategies are also looked into including impurity adjustment, doping, and surface modification. The full cells of NFPP were further analyzed, underscoring its potential for commercialization. In conclusion, we outline our opinions on the obstacles and future research priorities for NFPP. This review aims to assess the potential of NFPP for large-scale energy storage applications, sparking greater interest and progress in NFPP cathode materials.