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

Abstract

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 À25 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 À25 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 (À25, 25, and 65 C).

Recent Advances and Perspectives on the Promising High‐Voltage Cathode Material of Na3(VO)2(PO4)2F

“…[64,78] It should be noted that decorating with carbon materials is a facile and effective method to enhance the electronic conductivity, especially hybrid with graphene which possesses a high electron migration rate of above 1.5 × 10 4 cm −1 V −1 s −1 . [75,83,86,95,109,117] For example, Goodenough et al synthesized NVOPF(I4)/rGO sandwich structure through a simple solvothermal approach. [78] As shown in Figure 11a, the NVOPF(I4) nanocubes are uniformly dispersed between highly conductive rGO layers with the formation of a sandwich structure.…”

Progress and Challenges for All‐Solid‐State Sodium Batteries

“…In addition, sodium vanadium fluorophosphates, Na 3 V 2 O 2 (PO 4 ) 2 F (NVOPF), are one of the most promising polyanionic cathode materials, with high theoretical reversible capacity (130 mA h g −1 ) and working potential (≈3.6 and ≈4.0 V versus Na/Na + ), which has been widely researched. Recently, Li et al [ 135 ] assembled an NVOPF@reduced graphene oxide (rGO)/PFSA‐Na/Na ASSB with a high capacity of 81.2 mA h g −1 at 2C, and a long cycling performance of 88.1% capacity retention at 4 °C over 1000 cycles was obtained.…”