Design of organic–inorganic hybrid ion-gel electrolytes composed of borosilicate and allylimidazolium type ionic liquids

Abstract

Research towards the design of novel electrolytes for the development of safer and efficient Li-ion batteries has gained widespread momentum in recent years. Design of novel borosilicate glass/ionic liquid hybrid type electrolyte was undertaken. Organic–inorganic hybrids have the dual advantages of high ionic conductivity due to the organic component and high thermal stability due to the inorganic components. In the present work, an in-situ sol–gel method using alkoxysilanes and alkoxyboranes was carried out, in the presence of low viscous ionic liquids. This resulted in the formation of highly homogenous organic–inorganic hybrids. A low viscous diallylimidazolium type ionic liquid was employed as the organic component. Arrhenius plots evinced constant temperature dependence of ionic conductivity. A maximum ionic conductivity of 2.0 mS cm−1 at 51 °C, was observed among the prepared hybrids. LiPF6 based hybrids showed higher ionic conductivity due to larger phase separation order of organic and inorganic components which enables better connection of ion-conductive organic components. On the other hand, LiTFSA based hybrids were highly homogenous and exhibited much improved thermal stability.