3D nanofiber framework based on polyacrylonitrile and siloxane-modified Li6.4La3Zr1.4Ta0.6O12 reinforced poly (ethylene oxide)-based composite solid electrolyte for lithium batteries

Abstract

The application of solid-state electrolyte in lithium metal batteries is a promising technology to meet the demands for next-generation high-energy-density storage systems. Poly (ethylene oxide) (PEO)-based solid polymer electrolytes have been widely studied, but their electrochemical window is too narrow to be compatible with high-voltage cathodes and their mechanical properties are poor as well. Combination of organic and inorganic compounds is an effective approach to solve this limitation. In this study, Li6.4La3Zr1.4Ta0.6O12 (LLZTO) was surface-modified with a silane coupling agent and compounded with polyacrylonitrile (PAN) to form a 3D nanofiber framework via electrospinning technology, and the PEO-Succinonitrile (SN)-LiTFSI solution was uniformly dispersed in the 3D nanofiber framework to form a continuous Li+ transport path. The prepared composite solid electrolytes (CSEs) showed high ionic conductivity (1.58 × 10−4 S cm−1 at room temperature), a broad electrochemical window (5.1 V, vs. Li/Li+), and an attractive mechanical strength of 49.4 MPa. In addition, solid-state Li/CSE/NCM811 batteries exhibited high coulombic efficiency and significant stable cycling performance.