Na ₂ TiV ( PO ₄ ) ₃ @C composite with excellent Na‐storage performance based on a solid‐state polymer electrolyte membrane

Abstract

Na 2 TiV(PO 4) 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 Na 2 TiV(PO 4) 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. K E Y W O R D S cathode, Na 2 TiV(PO 4) 3 @C, PFSA-Na membrane, quasi-solid sodium-ion battery

The Progress in the Electrolytes for Solid State Sodium‐Ion Battery

“…Reproduced with permission. [ 64 ] Copyright 2020, Wiley. d) Schematic diagram of the preparation of QSSE and battery.…”

“…[63] Na-form perfluorinated sulfonic resin (PFSA-Na) membrane as the solid electrolyte was prepared, the ionic conductivity of the membrane still remained high and changed from 3.35 × 10 −3 to 8.7 × 10 −4 S cm −1 from 55 to 25 °C, thanks to the PFSA-Na membrane, the quasi solid-state battery with Na 2 TiV(PO 4 ) 3 @C as the cathode showed excellent specific capacity, stability, and rate performance (Figure 6c). [64] Wen et al developed ethoxylated trimethylolpropane triacrylate based quasi solid-state electrolyte (ETPTA-NaClO 4 -QSSE) using photopolymerization (Figure 6d), which possessed ionic conductivity of 1.2 mS cm −1 , a electrochemical window of >4.7 V versus Na + /Na, and outstanding flexibility; the Na 3 V 2 (PO 4 ) 3 (NVP)||ETPTA-NaClO 4 -QSSE||Na batteries displayed brilliant rate capability, with a recorded capacity of 55 mAh g −1 at 15 C. [65] Brief summary, PVdF-HFP based gel polymer with NaClO 4 , NaTf, NaTFSI salts, ionic liquids, organic solvents composition gel polymer electrolytes exhibited ≈10 −3 S cm −1 ionic conductivity. PAN-based GPEs with ethylene carbonate as plasticizing solvents also exhibited ≈10 −3 S cm −1 ionic conductivity.…”

“…c) Nyquist plots of liquid electrolyte battery and quasi-solid battery. Reproduced with permission [64]. Copyright 2020, Wiley.…”

Gel Polymer Electrolytes Design for Na‐Ion Batteries

“…Compared with the immersion method, the gel membrane prepared by the solution casting method has stronger intermolecular interactions, that is, the plasticizer is bonded to the polymer chain through the interaction of dehalogenation, nucleophilic substitution, and other reactions that occur during mixing. [ 100–108 ] Therefore, the resultant owned GPE membrane has higher thermal stability.…”