Ultra-thin ePTFE-enforced electrolyte and electrolyte-electrode(s) assembly for high-performance solid-state lithium batteries

Challenges including low stability, excessive thickness, a low ionic conductivity of current solid-state electrolytes, and large interfacial resistance in solid-state lithium batteries (SSLBs) hinder their application. Herein, an ultra-thin electrolyte (similar to 20 mu m) was prepared by using expanded porous polytetrafluoroethylene (ePTFE) as a framework and filling the pores with a hybrid electrolyte; it exhibited a high stability, mechanical strength, flexibility, and ionic conductivity (0.27 mS cm(-1)). A new mechanism for fast lithium-ion conduction in the composite electrolyte was creatively proposed, whereby the interface orients and concentrates lithium ions to accelerate ion transport. An electrolyte-electrode(s) assembly (EEA) was developed by directly spraying active material(s) with highly dispersed electrolytes on the electrolyte. EEA-based copper- and aluminum-free SSLBs with or without a low-dose liquid electrolyte achieved an excellent performance at room temperature. Furthermore, EEA-series-connected pouch batteries demonstrated high voltage, safety, and performance, making our ultra-thin electrolyte and EEA promising for the development of SSLBs.