Methanol-derived high-performance Na3V2(PO4)3/C: from kilogram-scale synthesis to pouch cell safety detection

Abstract

Na₃V₂(PO₄)₃ (NVP) is regarded as a potential cathode material that can be applied in sodium ion batteries (SIBs) owing to its NASICON structure. However, most of the reported works have focused on the synthesis of materials and the improvement of their electrochemical properties, with little research on the design and safety of pouch cells. Herein, we implemented a cost-saving route to realize the industrial-scale synthesis of NVP cathode materials. The obtained NVP samples possess an impressive Na-ion storage capability with high reversible capacity (116.3 mA h g⁻¹ at 0.2 C), superior power capability (97.9 mA h g⁻¹ at 30 C), and long lifespan (71.6% capacity retention after 2500 cycles at 20 C). It was remarkable that industrial-scale NVP/hard carbon (HC) sodium-ion pouch cells could be designed with an 823 mA h discharge capacity at a current of 200 mA (about 0.25 C), and which possess a long life and high rate performance (1000 cycles with a little decay at a current of 4000 mA). Besides, the pouch cells also exhibit excellent thermal stability when demonstrated for application in unmanned aerial vehicles (UAVs), and puncturing experiment results can further prove the excellent safety performance of NVP-hard carbon pouch cells.