Effects of Bulky LATP in PEO-based Hybrid Solid Electrolytes

Solid polymer electrolytes(SPEs) have been considered as the spotlight in recent years due to their high safety, non-flammability and good flexibility. Nonetheless, high crystallinity of polymer matrix leads to low ionic conductivity at ambient conditions and retards the practical applications of SPEs. Herein, we report hybrid solid electrolytes(HSE) containing bulky LATP in poly(ethylene oxide)(PEO) matrix, which significantly enhances the electrochemical properties. LATP has been easily obtained by an accessible solid-state method. The solid electrolyte based on 20 wt% LATP in PEO polymer matrix(abbreviated as PEO-20) exhibits an ionic conductivity of 2.1 ×10-5 S·cm-1 at 30 ℃, an order of magnitude higher than 2.9 × 10-6 S·cm-1 of the pristine PEO solid electrolyte(abbreviated as PEO-0), mainly resulting from the decline of crystallinity in polymer matrix. The electrochemical window of PEO-20 can reach 4.84 V at room temperature, compared with 4.40 V for PEO-0, which could be compatible with high-voltage cathode materials.