Sodium‐Ion Battery based on an Electrochemically Converted NaFePO₄ Cathode and Nanostructured Tin–Carbon Anode

We report a new sodium-ion battery formed by coupling a NaFePO(4) cathode and a nanocomposite tin-carbon (Sn-C) sodium-alloying anode. The NaFePO(4) cathode is obtained by Li-Na conversion of a LiFePO(4) cathode directly in the full cell employing the Sn-C anode and a sodium-ion electrolyte. The results show that the unique approach adopted here is capable of successfully and efficiently converting LiFePO(4) into NaFePO(4) in a sodium-ion battery operating at a voltage of 3 V, with a maximum reversible capacity of 150 mAh g(-1), high reversibility, and high rate capability.