Reversible Multielectron Redox Chemistry in a NASICON‐Type Cathode toward High‐Energy‐Density and Long‐Life Sodium‐Ion Full Batteries

Abstract Na‐superionic‐conductor (NASICON)‐type cathodes (e.g., Na 3 V 2 (PO 4 ) 3 ) have attracted extensive attention due to their open and robust framework, fast Na + mobility, and superior thermal stability. To commercialize sodium‐ion batteries (SIBs), higher energy density and lower cost requirements are urgently needed for NASICON‐type cathodes. Herein, Na 3.5 V 1.5 Fe 0.5 (PO 4 ) 3 (NVFP) is designed by an Fe‐substitution strategy, which not only reduces the exorbitant cost of vanadium, but also realizes high‐voltage multielectron reactions. The NVFP cathode can deliver extraordinary capacity (148.2 mAh g −1 ), and decent cycling durability up to 84% after 10 000 cycles at 100 C. In situ X‐ray…

• NN
  National Natural Science Foundation of China

  Awards: 52272260, 52002407, 51932011
• NS
  Natural Science Foundation of Hunan Province

  Awards: 2021JJ40730, 2023JJ10060