A Room-Temperature Ionic-Liquid-Templated Proton-Conducting Gelatinous Electrolyte

Novel proton-conducting gelatinous electrolytes templated by room-temperature ionic liquid (RTIL) 1-butyl-3-methyl-imidazolium-tetrafluoroborate (BMImBF 4 ) have been prepared in methylsisesquioxane backbone containing H 3 PO 4, and the influences of the RTIL on the structure, morphology, thermal stability, and electrochemical properties of the gelatinous electrolytes have been examined. X-ray diffraction and scanning electron microscopy proved that BMImBF 4 acted as structure-directing template during the sol−gel process of methyl-trimethoxysilane. X-ray photoelectron spectra and infrared spectroscopy demonstrated that the hydrogen-bonding was formed between BMImBF 4 and H 3 PO 4 . The electrolytes had good thermal stability up to 300 °C and showed superior mechanical and electrochemical properties. A room-temperature conductivity of 1.2 × 10 -3 S cm -1 was obtained for the electrolyte at the molar ratio of RTIL/Si/H 3 PO 4 0.3/1/1, and its electrochemical window was up to 1.5 V. The satisfactory thermomechanical and electrochemical properties of the obtained electrolytes make them promising materials in various electrochemical devices, such as batteries, fuel cells, sensors, and electrochromic windows.