Enhanced Cycle Performance of Polyimide Cathode Using a Quasi-Solid-State Electrolyte

Benefiting from flexible molecular structures, low limitation of cationic radius, and environmental friendliness, organic materials are regarded as promising candidates for rechargeable batteries. However, the high-solubility in organic electrolytes is the most challenging issue. Most efforts have been focused on modification of the electrode materials. Herein, we employ a sodium ion conducting gel polymer electrolyte with interconnected pores to improve the cycle performance of a polyimide (PI) cathode. Compared to a commercial glass fiber separator, the gel polymer electrolyte only lets through Na ions but prevents the dissolved PI, and thereby avoids further dissolution. After utilization of the membrane, organic sodium ion batteries based on a PI cathode shows a highly enhanced cyclability (80% after 1000 cycles). Such a strategy can be potentially extended to many organic materials used in rechargeable batteries to ensure stability and safety.