Synergistic Advancements of Acrylate-Grafted Poly(vinylidene Fluoride-co-hexafluoropropylene) Gel Polymer Electrolytes for Lithium-ion Batteries

Gel polymer electrolytes (GPEs) are gaining prominence in the realm of lithium-ion (Li-ion) batteries due to their remarkable thermal stability and superior electrochemical performance. This article endeavors towards a novel approach for developing GPEs to enhance Li-ion battery performance. Leveraging acrylate-grafted poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), we employed atom transfer radical polymerization (ATRP) to graft four acrylic monomers—lauryl methacrylate (LM), pentaerythritol diacrylate (PEDA), pentaerythritol triacrylate (PETA), and tris(2-hydroxyethyl) isocyanurate triacrylate (THICTA)—onto PVDF-HFP. The effects of grafting acrylates on the properties of PVDF-HFP composite polymer films including chemical bonding, morphology, porosity, and thermal properties, as well as the electrochemical properties and cycling stability of the composite film-based gel polymer electrolyte (GPE), are studied. The resulting high porosity and increased β phase of PVDF-HFP, particularly when grafted with PEDA, significantly improved the ionic conductivity and electrochemical performance of LiFePO₄ cells, leading to superior rate capability and excellent cycling stability. The ease of employing the GPE emphasizes the potential of PVDF-HFPgPEDA as a high-performance option for Li-ion polymer batteries, contributing to ongoing efforts in advancing energy storage through enhanced thermal stability along with electrochemical advantages.