Gel polymer electrolyte composites in sodium-ion batteries: Synthesis methods, electrolyte formulations, and performance analysis

Gel polymer electrolytes (GPEs) are prevalent in battery research because they are flexible, lightweight, and promote reasonable contact between components. Sodium-ion batteries (NIBs) are gaining recognition as promising options for future energy storage due to their cost-effectiveness and environmental friendliness. To enhance safety, replacing traditional organic electrolytes with polymer electrolytes can prevent issues like thermal instability and electrolyte leakage. Polymer electrolytes (PEs) face high interfacial impedance and low ionic conduc- tivity. GPEs offer a solution by balancing high ionic conductivity, thermal stability, low interfacial impedance, and flexibility. This review article discusses various methods for synthesizing GPEs and compares electrolytes for NIBs. It also highlights recent cathode and anode-material advancements, supported by schematic illustrations for clarity. Additionally, the article examines GPE composites for their electrochemical properties through a detailed analysis. This review could provide a thorough comprehension of sodium-ion GPEs and help shape how molecules interact to improve the performance of gel polymers NIBs.