Fast-charging Na4Fe3(PO4)2P2O7 cathode for sodium-ion batteries

Developing fast-charging secondary batteries is a key strategy to enhance the utilization of renewable energy sources and achieve global carbon neutrality. Based on the intrinsic properties of sodium and its resource advantages, sodium-ion batteries hold promising prospects in this field. As a crucial component of batteries, efficient cathode materials are vital for the realization of fast-charging technology. Na₄Fe₃(PO₄)₂P₂O₇, as a high-performance polyanionic cathode material, shows great potential for fast-charging and warrants further research. However, its practical application is still hindered by intrinsically low electronic conductivity, sluggish Na⁺ diffusion kinetics, and the formation of undesired impurity phases during synthesis. The current research status and modification strategies for fast-charging Na₄Fe₃(PO₄)₂P₂O₇ cathodes mainly focus on three aspects: surface and morphology modification, active component modulation, and inhibition of impurity generation. This review provides a summary of these approaches, aiming to offer insights into the rational design and further development of NFPP as a fast-charging cathode for sodium-ion batteries.