Flexible Organic–Inorganic Hybrid Solid Electrolytes Formed via Thiol–Acrylate Photopolymerization

Abstract

Novel flexible organic–inorganic hybrid solid electrolytes with controlled network structures (cnHSEs) were formed via thiol–acrylate photopolymerization under UV irradiation, using a series of thiol-modified silica nanoparticles and poly(ethylene glycol) diacrylate. Because of the outstanding lithium ion mobility that is readily identifiable in the solid-state nuclear magnetic resonance spectra, the flexible cnHSEs demonstrate a relatively high ionic conductivity even at low temperature of −20 °C and up to the maximum of 7.3 × 10–4 S cm–1 at 30 °C. The ionic conductivity herein is higher than that for typical solid polymer electrolytes at the identical temperature. Additionally, the lithium ion transference number is also improved simultaneously up to 0.7 more due to the scavenger effect of silica nanoparticles embedded in the system. Moreover, the cnHSEs show a broad electrochemical stability window, and the fabricated cell comprising Li|cnHSEs|LiFePO4 exhibits a highly reversible electrochemical reacti...