Swellable Polyimide Gel Electrolyte Membranes for Lithium-Ion Batteries with High Safety and Electrochemical Stability

With the growing adoption of lithium-ion batteries in electric vehicles and other applications, safety concerns have become increasingly critical. To address these challenges, gel polymer electrolytes have re-emerged as a focal point due to their hybrid advantages of solid- and liquid-state electrolytes. This study presents designed polyimide-based gel polymer electrolyte membranes for superior safety and electrochemical stability through precise molecular engineering. The polymer incorporates ether bonds to coordinate lithium ions while simultaneously imparting chain flexibility. This structural optimization enhances the phase separation, enabling efficient lithium-ion transport while improving cycling stability and safety. The resulting gel polymer electrolyte membrane demonstrated exceptional thermal stability with a high lithium-ion transference number of 0.41, and remarkable cycling performance with 95% capacity retention over 450 cycles at 0.5C at room temperature, indicating their stable electrode/electrolyte interfaces, which offer a promising pathway for safe and high-performance energy storage devices.