Preparation and interface stability of alginate-based gel polymer electrolyte for rechargeable aqueous zinc ion batteries

Gel polymer electrolytes (GPE) endow zinc-ion batteries (ZIBs) with the properties of intrinsic safety, high performance, and promising applications for energy storage systems. However, the electrochemical performance of ZIBs with GPE is limited by low ion conductivity and poor interface contact. In this work, a novel sodium alginate/polyvinyl alcohol/polyvinyl pyrrolidone composite GPE were obtained by solution casting and solvent displacement methods. The optimized GPE exhibited high ion conductivity of 9.46 × 10−3 S cm−1 and excellent mechanical strength. The flexible ZIBs assembled with prepared GPE showed a specific capacity of 109.3 mAh g−1 and a capacity retention of 68.0 % after 1000 cycles at 1C. It also maintained perfect long-term cycling stability and high coulombic efficiency (CE) of nearly 100 %. The advantages of the prepared electrolyte could broaden the scope of applications of ZIBs.