Synergistic Preparation of High-Performance Gel Electrolytes via Pore Morphology Regulation and Liquid Metal Modification

Solid-state batteries have attracted much attention due to their safety and energy density. Polyvinylidene fluoride (PVDF)-based solid polymer electrolyte (SPE) shows great application potential due to its excellent flexibility, mechanical properties, and processing performance. However, limited ionic conductivity restricts its application. In addition, suppressing the growth of lithium dendrites is another key issue to be solved in solid-state batteries. Adding ionic conductive fillers (e.g., Li₇La₃Zr₂O₁₂) to increase ionic conductivity is the main method. In previous work, we found that surface modification of Li₇La₃Zr₂O₁₂ with gallium-based liquid metal can improve interfacial compatibility and inhibit the growth of lithium dendrites, thereby improving the battery's performance. In this study, we combined LM-modified Li₇La₃Zr₂O₁₂ with PVPF-HFP and used the phase separation method to fabricate composite films with a porous network. After absorbing the electrolyte, gel electrolytes (GPEs) were obtained. With the modification of the filler and optimization of pore size and connectivity, the gel electrolyte achieved an ionic conductivity of 3.8 × 10^-3 S·cm^-1 at room temperature. The half-cell equipped with the modified gel electrolyte can cycle 400 times at 1C with a retention rate of 96.24%, showing promising cycling stability. This research provides insight into the design and application of gel electrolytes.