A Semisolid Electrolyte for Flexible Zn-Ion Batteries

Mechanically strong, ionically conductive, and operationally safe electrolytes are of paramount importance to flexible and wearable electronics. Herein, we report a three-dimensional, double-cross-linked gelatin and sodium alginate hydrogel imbibed with ZnSO4 aqueous solution as an electrolyte membrane for flexible Zn-ion batteries. We show that the designed polymer electrolyte membrane exhibits superior properties in ionic conductivity, mechanical flexibility, electrochemical stability, and compatibility with the Zn anode. The resultant Zn-ion battery outperforms the baseline liquid counterpart in capacity, rate capability, and cycle stability, making it a promising electrolyte membrane candidate for flexible batteries for wearable electronics.