Research progress on the mechanism and key role of filler structure on properties of PVDF composite solid electrolyte

Solid-state lithium batteries (SSBs) have attracted attention as the next-generation high-safety lithium batteries due to their high energy density, excellent security, and electrochemical stability. Currently, polyvinylidene fluoride (PVDF) is considered one of the most crucial materials in solid polymer electrolytes because of its flexibility and workability. However, PVDF-based solid electrolytes encounter challenges such as low electrical conductivity and high internal resistance. The electrochemical properties of these solid electrolytes can be effectively enhanced through composite design and molecular structure modification. This review specifically focuses on the impact of nano-fillers with different structures (zero-dimensional nanoparticles, one-dimensional nanofibers, two-dimensional nanosheets, and three-dimensional nanoskeleton structures) on the key properties of PVDF-based solid electrolytes. The specific focus is on optimizing ion conductivity, improving lithium-ion migration efficiency, expanding the electrochemical stability window, extending battery life, enhancing electrical performance stability, and increasing battery capacity. The goal is to explore innovative filler design and modification technology application strategies in order to effectively enhance the performance of PVDF-based solid electrolytes in the field of solid lithium-ion batteries.