Low-Operating Temperature, High-Rate and Durable Solid-State Sodium-Ion Battery Based on Polymer Electrolyte and Prussian Blue Cathode

A solid-state polymer electrolyte (PFSA-Na membrane) for solid-state sodium-ion batteries (SSIBs) to overcome severe safety issues caused by traditional liquid electrolytes is explored. The PFSA-Na membranes, synthesized by an environmentally and economically friendly method, display high ionic conductivity, excellent thermal stability, and outstanding mechanical flexibility in a wide temperature range. SSIBs based on the PFSA-Na membranes and Prussian blue cathode exhibit a superior rate performance of 87.5 mA h g(-1) at 8 C and a durable cycling life of up to 1100 cycles at 1 C with only a slight capacity decay of approximate to 0.014% per cycle. Furthermore, due to the intrinsic advantages of the PFSA-Na membranes, the cyclic performance of the proposed SSIBs is more stable than that of its liquid counterpart even at the rather low temperature of -35 degrees C.