Preparation and application of poly(ethylene oxide)‐based all solid‐state electrolyte with a walnut‐like SiO 2 as nano‐fillers

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, LiClO 4 , and the independently synthetized walnut‐like SiO 2 (WLS) as nano‐fillers, is designed and prepared by the tape‐casting way. The optimum mass fraction of walnut‐like SiO 2 is determined by physical and electrochemical characterization. The result shows that the PLWLS‐15 with 15 wt % walnut‐like SiO 2 nanoparticles has a crystallinity of 13.7%. Similarly, the maximum tensile strength is improved greatly. The assembled all‐solid‐state lithium‐ion battery with LiFePO 4 /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. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48810.