Carbon‐Coated NaVPO4F as a High‐Capacity Cathode for Aqueous Sodium‐Ion Battery

Abstract NaVPO 4 F has garnered significant attention as a promising cathode material for non‐aqueous sodium‐ion batteries due to its high theoretical specific capacity and appropriate potential. However, the dissolution of vanadium component of NaVPO 4 F in aqueous electrolytes has restricted its application in aqueous sodium‐ion batteries (ASIBs). Herein, we report the use of carbon‐coated NaVPO 4 F as a cathode material in ASIBs. This cathode material exhibited a discharge capacity of 111 mAh g −1 at 0.5 A g −1 in a concentrated 17 m NaClO 4 aqueous solution and demonstrated capacity retention of 74.4 % over 100 cycles. The experimental results confirmed that the carbon coating on NaVPO 4 F and high‐concentration NaClO 4 aqueous electrolyte exhibited positive effects in restraining vanadium dissolution. Additionally, when configuration with NaTi 2 (PO 4 ) 3 @C as anode, the full cell exhibited a capacity of 43.9 mAh g −1 with an average operating voltage of 1.2 V at a current density of 0.5 A g −1 in a concentrated 17 m NaClO 4 aqueous electrolyte. These outcomes underscore the potential of NaVPO 4 F@C as a promising cathode material for ASIBs.