A Sodium-Ion Battery with a Low-Cost Cross-Linked Gel-Polymer Electrolyte

The design of a sodium-ion rechargeable battery with an antimony anode, a Na₃V₂(PO₄)₃ cathode, and a low-cost composite gel-polymer electrolyte based on cross-linked poly(methyl methacrylate) is reported. The application of an antimony anode, on replacement of the sodium metal that is commonly used in sodium-ion half-cells, reduces significantly the interfacial resistance and charge transfer resistance of a sodium-ion battery, which enables a smaller polarization for a sodium-ion full-cell Sb/Na₃V₂(PO₄)₃ running at relatively high charge and discharge rates. The incorporation of the gel-polymer electrolyte is beneficial to maintain stable interfaces between the electrolyte and the electrodes of the sodium-ion battery at elevated temperature. When running at 60 °C, the sodium-ion full-cell Sb/Na₃V₂(PO₄)₃ with the gel-polymer electrolyte exhibits superior cycling stability compared to a battery with the conventional liquid electrolyte.