High‐power and low‐cost sodium‐ion batteries with a wide operation temperature from −70 °C to 130 °C

Abstract

Low‐cost sodium‐ion batteries (SIBs) are promising candidates for grid‐scale energy‐storage systems, and the wide‐temperature operations of SIBs are highly demanded to accommodate extreme weather. Herein, a low‐cost SIB is fabricated with a Na4Fe3(PO4)2P2O7 (NFPP) cathode, a natural graphite (NG) anode, and an ether‐based electrolyte. The prepared NG//NFPP batteries deliver a long lifespan of 1000 cycles, high‐power density of 5938 W/kg, and remarkable rate performance of 10 A/g with a high capacity retention of 60%. Benefiting from the solvent co‐intercalation process of the NG anode and the high Na+ diffusion rate of the NFPP cathode, the NG//NFPP battery displays outstanding performance at −40 °C and even can work at an ultralow temperature of −70 °C. Furthermore, the high boiling point of the electrolytes and high thermal stability of the electrode materials also enable the high‐temperature operation of the full battery up to 130 °C. This work will guide the design of the wide‐temperature SIBs.