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

Abstract

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. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48810.

Increase of Solid Polymer Electrolyte Ionic Conductivity Using Nano-SiO2 Synthesized from Sugarcane Bagasse as Filler

“…The addition of nano-SiO 2 7% resulted in the lowest peak, indicating that the solid electrolyte polymer had the lowest crystallinity and had highest amorphous phase. The addition of larger amounts of nano-SiO 2 produce aggregate rather than reducing the degree of crystallinity [ 4 ]. This can be attributed to the ion conductivity of PEO/NaClO 4 with nano-SiO 2 7% which decreased to 8.84 × 10 −8 S/cm.…”

“…However, the ionic conductivity decreased to 8.84 × 10 −8 S/cm after 7% of nano-SiO 2 was added to the solid electrolyte polymer. This increase in ionic conductivity is due to decrease in the degree of crystallinity and generates more amorphous region [ 4 ]. The steric inhibition effect of nano-SiO 2 means a solid polymer electrolyte ion transport occurs via intra-chain and inter-chain charge transfer in the amorphous phase [ 14 ].…”

“…However, liquid electrolyte has several disadvantages in the application of the battery. Liquid electrolyte contains volatile and flammable compounds that have been related to battery burning or explosion accidents [ 4 ]. Solid polymer electrolyte has been considered as a safer component to be used in batteries, due to its versatility and thermodynamic stability [ 5 ].…”

“…The application of silica nanoparticles as fillers in polymer nanocomposites has drawn much attention, due to improvement in thermal, mechanical, physical and chemical properties [ 17 ]. Nano-SiO 2 as nano filler in the SPE shows some prospective applications [ 4 ].…”

Advanced Composite Solid Electrolytes for Lithium Batteries: Filler Dimensional Design and Ion Path Optimization

“…Although SiO 2 nanoparticles are a typical 0D filler for solid polymer electrolytes, specially treated SiO 2 with different morphologies or surface groups still attracts researchers' interest. [102][103][104][105][106] Wang et al synthesized a new kind of SiO 2 nanoparticle with a novel walnut-like morphology by the tapecasting technique. [102] The large surface area of this walnut-like morphology provided abundant contact area between lithium salt and nanoparticles.…”