Unraveling Electrochemical Properties of Diglyme‐Based Gel Polymer Electrolyte Nanocomposite Toward Application in Nonaqueous Zinc‐Ion Batteries

ABSTRACT Zinc‐ion batteries (ZIBs) are receiving global attention due to their environment‐friendly nature, resource abundance, high energy density, low cost, and safety. Herein, we report a nonaqueous Zn‐ion‐conducting flexible gel polymer electrolyte (S‐GPE) nanocomposite dispersed with silica nanopowder for application in ZIBs. The free‐standing S‐GPE films comprise 0.5 M zinc bis(trifluoromethylsulfonyl)imide dissolved in diglyme, entrapped in poly(vinylidene fluoride‐co‐hexafluoropropylene) dispersed with SiO 2 nanopowder. Morphological/structural/thermal properties and ion‐polymer‐filler interactions are monitored via field‐emission scanning electron microscopy, x‐ray diffraction, thermal analysis, and Fourier‐transform infrared spectroscopy. Wide‐enough potential range (~2.52 V), optimum ionic conductivity () and enhanced Zn‐ion transport number ( t Zn 2+ ~ 0.6) due to filler dispersion are the electrochemical properties that make the S‐GPE film a potential electrolyte for solid‐state ZIBs. The Zn sheet as an anode shows excellent interfacial stability when interfaced with the S‐GPE film, as evident from Zn‐stripping‐plating, and offers improved behavior as compared to the interface with undispersed GPE film. The performance of the S‐GPE film in ZIB cell, assembled with Zn anode and V 2 O 5 cathode (ball‐milled with super‐P), exhibits a discharge capacity of ~117 mAh g −1 for 240 charge–discharge cycles at a 0.1 C rate, high‐rate capability up to a 1 C rate, and Coulombic efficiency > 98%. Thus, the study demonstrates the potential of S‐GPE film as an efficient flexible electrolyte for the development of nonaqueous ZIBs.