(689f) Effects of Carbide and Oxide Filler Materials on the Ionic Conductivity of Poly(ethylene glycol) Diacrylate (PEGDA) Solid Electrolytes

Solid-state polymer electrolytes (SPEs) provide significant advantages in the production of state-of-the-art lithium metal batteries compared to conventional liquid electrolytes. SPEs are less flammable than many organic solvent based liquid electrolytes and provide resistances to many unwanted interactions in high energy battery systems. The ionic conductivities of many SPEs are substantially lower than their liquid electrolyte counterparts. The addition of filler materials is a promising method to improve the room temperature ionic conductivities of SPEs. Fillers improve the ionic conductivity of polymer electrolytes by reducing the crystallinity of the matrix or by directly participating in ionic transport. Studies on the ionic transport potential of filler materials in all-solid-state poly(ethylene glycol) diacrylate (PEGDA) electrolytes are presently limited. This study presents an in-depth comparison of ionic conductivity enhancement for various filler materials in an all-solid-state PEGDA electrolyte matrix. Through the addition of various metal oxides (Al₂O₃ and V₂O₅), metalloid oxides (SiO₂), and metal carbides (NiWC) at different concentrations, the effects of filler type and concentration on the ionic conductivity of UV-cured PEGDA electrolytes were examined with electrochemical impedance spectroscopy. Particle dispersion of the filler materials, their effects on the crystallinity and examination of the polymerization characteristics of the PEGDA were examined using SEM/EDS, XRD, and FTIR. By adding filler materials, polymer electrolyte ionic conductivities of 10^-5 to 10^-4 S/cm can be achieved. This study compares the benefits and drawbacks of different filler materials within a comparable polymer matrix and examines the effects that newly implemented carbide fillers have on solid-state electrolytes for the first time. Understanding the role of filler materials in the PEGDA matrix will provide insight into synthesis of high ionic conductivity solid-state electrolytes for lithium-ion and lithium-sulfur batteries as well as guide the implementation of future fillers in polymer electrolytes.