Nanocomposite All-Solid-State Polymer Electrolyte for High-Performance Lithium Batteries

Abstract

An inorganic-polymeric hybrid all-solid-state electrolyte (SSE) composed of chemically modified nano-silica, linear poly(trifluoroethyl methacrylate)-co-poly(poly(ethylene glycol) methyl ether methacrylate copolymer (PTFEMA-co-PPEGMA or LCP) and lithium salt is prepared and used in lithium-ion batteries (LIBs) for the first time. Nano-silica is transformed to SiO2-SH via esterification reaction. Then, SiO2-PEGMA is synthesized through click chemistry of SiO2-SH and PEGMA. The compatibility of the nano-SiO2 and the LCP can be effectively improved due to the excellent dispersibility of the chemically modified nano-SiO2 in the polymer matrix. As a result, the hybrid SSE has good thermal stability, excellent film-forming ability. Furthermore, the hybrid SSE shows superior comprehensive electrochemical properties, which makes the corresponding LiFePO4/Li cells have good cycling performance (the discharge capacity reaches 144 mAh g−1 at 0.3 C) and rate capability (90 mAh g−1 is reached at 1 C). Thus, the hybrid electrolyte can be a powerful SSE for high-safety and high-performance LIBs.