Bifunctional Na-Deficient Strategy Induced Pure Phase Na4-xFe3(PO4)2P2O7 Cathode with High Capacity for Sodium-Ion Batteries

Iron-based mixed phosphate-pyrophosphate Na4Fe3(PO4)2(P2O7) (NFPP) as a cathode material for sodium-ion batteries (SIBs) exhibits promising commercial prospects due to its excellent structural stability, high theoretical capacity, and cost advantages. However,...