Impact of Ionic Liquid Functionalized ZrO2 Nanoparticles on Poly (stearyl methacrylate) Grafted Poly (vinylidene fluoride‐co‐hexafluoropropylene) Based Highly Conductive Gel Polymer Electrolytes for Lithium‐Metal Batteries

Abstract

AbstractIn this study, an organic‐inorganic hybrid polymer membrane is successfully designed and developed by grafting stearyl methacrylate (SMA) side chains onto the backbone of the P(VDF‐HFP) copolymer followed by blending with varying amounts of imidazolium ionic liquids functionalized ZrO2 nanoparticles. Different microporous gel polymer electrolytes (MGPEs) are prepared by immersing the membranes into a LiTFSI salt‐dissolved ionic liquid electrolyte. The membranes′ crystallinity, surface morphology, porosity, and thermal stability are investigated using various characterization techniques. The copolymer membrane blended with 60 wt % functionalized nanoparticles exhibits the highest porosity of 64.5 %, which allows it to achieve a maximum electrolyte uptake of 387 wt %. That enables the corresponding MGPE to achieve the highest room temperature lithium ion conductivity of ~5.34×10−3 S cm−1 with a wide electrochemical stability window and good electrochemical stability against Li metal. Leveraging these advantageous characteristics, the lab‐scale truly solid‐state Li|MGPE|LiFePO4 and Li|MGPE|LiNi0.8Mn0.1Co0.1O2 cells demonstrate excellent rate capability and reversible cycling stability while maintaining high specific capacities (up to 154 and 172 mAh g−1, respectively, at 0.5 C) with >99.0 % coulombic efficiency over 100 cycles. Such exceptional interfacial compatibility with both low‐ and high‐voltage cathodes establishes the applicability of these newly developed MGPEs in next‐generation all‐solid‐state lithium‐metal batteries.