Research on the Mechanism of Space Charge Layer in Gel Electrolyte: Synergistic Effects of PFPE Networks and Li₂O

Abstract The increasing demand for energy in portable electronics and electric vehicles has highlighted the necessity for lithium‐ion batteries that offer high energy density, safety, and long cycle life. To address this challenge, this study introduces a novel gel polymer electrolyte (GPE) based on a poly(vinylidene fluoride‐co‐hexafluoropropylene)‐perfluoropolyether methacrylate (PH‐PFPE) 3D network structure, integrated with lithium oxide (Li₂O) fillers that form a space charge layer (SCL). Lithium metal batteries (LMBs) utilizing this new gel electrolyte demonstrate exceptional rate performance across a broad current density range (0.2 to 4 C) and retain 95.64% of their capacity after 1500 cycles at 3 C. This paper provides a comprehensive analysis of the microstructure and interfacial properties of both the electrode materials and gel electrolytes. Furthermore, molecular dynamics simulations reveal the molecular‐level synergistic effect between the polymer and fillers, which significantly enhances lithium‐ion transport.