Synergistic Effects of Plasticizer and 3D Framework toward High-Performance Solid Polymer Electrolyte for Room-Temperature Solid-State Lithium Batteries
Jia Wang, Jing Yang, Lin Shen, Qingya Guo, Hao He, Xiayin Yao
Abstract
Solid polymer electrolytes (SPEs) can alleviate the safety issues existing in commercialized lithium ion batteries with liquid electrolyte. However, the low room-temperature ionic conductivity and poor mechanical properties of current polymer electrolyte hinder its practical applications. Herein, a composite solid polymer electrolyte consisting of poly(ethylene oxide) (PEO), the solid plasticizer succinonitrile (SN), and a 3D framework glass fiber (GF) with high ionic conductivity and good mechanical property is proposed. The optimized composite electrolyte PEO–SN25–LiTFSI10–GF has a room-temperature ionic conductivity of 2.85 × 10–4 S cm–1, which is 100 times higher than that of pristine PEO. An electrochemical window up to 5.5 V and a tensile strength of over 8 MPa are also exhibited by the optimized composite electrolyte. The solid-state LiFePO4/PEO–SN25–LiTFSI10–GF/Li battery shows good cyclic performance with a capacity retention of 98.5% after 100 cycles at 0.2 C under room temperature, demonstrating a promising polymer composite electrolyte for the next-generation solid-state lithium batteries with high energy density and high safety.