Preparation and application of poly(ethylene oxide)-based all solid-state electrolyte with a walnut-like SiO2 as nano-fillers

摘要

Poly(ethylene oxide) (PEO) is one of the most promising candidates in polymer solid-state electrolyte. However, the polymer matrix has a high degree of crystallinity and thus manifests low conductivity, which restricts its application in all solid-state lithium-ion battery. Herein, a new composite polymer electrolyte (PLWLS), which is comprised of PEO, LiClO4, and the independently synthetized walnut-like SiO2 (WLS) as nano-fillers, is designed and prepared by the tape-casting way. The optimum mass fraction of walnut-like SiO2 is determined by physical and electrochemical characterization. The result shows that the PLWLS-15 with 15 wt % walnut-like SiO2 nanoparticles has a crystallinity of 13.7%. Similarly, the maximum tensile strength is improved greatly. The assembled all-solid-state lithium-ion battery with LiFePO4/PLWLS-15/Li exhibits a higher discharge capacity of 167 mAh g(-1) at 0.1 C (1C = 170 mAh g(-1)) and 143 mAh g(-1) at 0.5 C in first cycle, lower voltage polarization and better cycle performance. Therefore, adding nanoparticle into PEO-based solid-state electrolyte could effectively promote the mechanical property and electrochemical performance, and thus provide a possibility of application for PLWLS-15 in next generation all solid-state lithium battery. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48810.