Nonflammable hybrid solid electrolyte membrane for a solid-state lithium battery compatible with conventional porous electrodes

Abstract

Solid-state lithium batteries are highly promising for energy storage applications because of their high energy density and good safety characteristics. To promote the commercial progress of solid-state lithium batteries, solutions are desirable for two limitations of the technology: the low ionic conductivity of solid electrolytes and interfacial compatibility between electrolyte and electrodes. Here, we develop a hybrid solid electrolyte composed of Li7La3Zr2O12, ionic liquid, LiTFSI, and PVDF-HFP. Because its components are nonflammable, the hybrid solid electrolyte is likewise completely nonflammable. After pressing, the thickness of the hybrid solid electrolyte can be adjusted. The phase conversion of β-phase PVDF-HFP reduces the barrier of ionic conduction because of enhanced organic–inorganic interfacial ion transfer. More importantly, the ionic liquid stored in the hybrid solid electrolyte not only enhances the conductivity of the electrolyte but also solves the interfacial compatibility issue between solid electrolytes and conventional porous electrodes.