Na3V2O2(PO4)2F Cathode for High-Performance Quasi-Solid-State Sodium-Ion Batteries with a Wide Workable Temperature Range

Solid-state batteries have attracted significant attention due to their safety, but most studies focus on room-temperature performance. Herein, the electrochemical performance of quasi-solid-state sodium-ion batteries (SIBs) based on the perfluorosulfonate-based polymer electrolyte (PFSA-Na) and Na 3 V 2 O 2 (PO 4 ) 2 F (NVOPF) cathode over a wide temperature range (from −25 to 65 °C) is investigated. The quasi-solid-state half-cells (Na//PFSA-Na//NVOPF@rGO) exhibit a long-term cycle life (88.1% capacity retention at 4 C after 1000 cycles) at room temperature. A high discharge capacity can be maintained even at a low temperature of −25 °C and it can be restored to the original value when the temperature increases again to 25 °C. Meanwhile, full-cells (hard carbon//PFSA-Na//NVOPF@rGO) can also deliver stable cycling performance in a wide temperature range (−25, 25, and 65 °C).