An Advanced High‐Entropy Fluorophosphate Cathode for Sodium‐Ion Batteries with Increased Working Voltage and Energy Density

Abstract Impossible voltage plateau regulation for the cathode materials with fixed active elemental center is a pressing issue hindering the development of Na‐superionic‐conductor (NASICON)‐type Na 3 V 2 (PO 4 ) 2 F 3 (NVPF) cathodes in sodium‐ion batteries (SIBs). Herein, a high‐entropy substitution strategy, to alter the detailed crystal structure of NVPF without changing the central active V atom, is pioneeringly utilized, achieving simultaneous electronic conductivity enhancement and diffusion barrier reduction for Na + , according to theoretical calculations. The as‐prepared carbon‐free high‐entropy Na 3 V 1.9 (Ca,Mg,Al,Cr,Mn) 0.1 (PO 4 ) 2 F 3 (HE‐NVPF) cathode can deliver higher mean voltage of 3.81 V…

• NN
  National Natural Science Foundation of China

  Awards: 52173246, 91963118, 52102213