One-step radiation synthesis of novel star-shaped polymeric ionic liquid–POSS gel electrolytes with high ionic conductivity and mechanical properties for supercapacitor

Polymeric ionic liquids (PILs) not only have the unique properties of ionic liquid, but also possess diverse mechanical properties of polymers. Due to their safety and conductivity, PILs-based gel polymer electrolytes (GPEs) are the promising candidates for the design of the devices. Here, we reported a facile approach to synthesize novel star-shaped GPE (named PIL–POSS–Li GPE) based on 1-vinyl-3-butylimidazolium hexafluorophosphate ionic liquid, octavinyl polyhedral oligomeric silsesquioxane (POSS) and LiPF6 solution in one step via gamma-ray radiation. Compared with PIL–Li GPE without POSS, the incorporation of POSS into the PIL–Li GPE can improve properties of PIL–POSS–Li GPE due to the formation of a star-shaped structure, and the as-prepared PIL–POSS–Li GPE showed excellent compressive strength of 1617 kPa, high fracture compression stain of 79% and high ionic conductivity of 3.88 mS cm−1 at 25 °C. What is more, the PIL–POSS–Li supercapacitor (SC) showed better electrochemical performance than PIL–Li SC.