Na2TiV(PO4)3@C composite with excellent Na‐storage performance based on a solid‐state polymer electrolyte membrane.

Summary: Na2TiV(PO4)3 compound can be used as a cathode material for sodium‐ion battery for its good stability, high operating potential, and low material cost. In this work, a quasi‐solid sodium‐ion battery with Na2TiV(PO4)3@C as the cathode and Na‐form perfluorinated sulfonic resin (PFSA‐Na) membrane as the solid electrolyte were assembled and tested. It is worth mentioning that compared with liquid electrolyte battery, the quasi‐solid sodium‐ion battery displays better cycle and rate performance. At a different current density of 50, 100, 200, 500, and 1000 mA g−1, the quasi‐solid sodium‐ion battery shows specific capacities of 125, 110, 96, 73, and 45 mA h g−1, respectively. And after 300 cycles, the specific capacity still remains ~90 mA h g‐1, which is far better than liquid electrolyte battery (~70 mA h g‐1). The good result is due to the assembly of quasi‐solid batteries and the application of PFSA‐Na solid electrolyte. [ABSTRACT FROM AUTHOR]