Polyhedral oligomeric silsesquioxane containing gel polymer electrolyte based on a PMMA matrix

Abstract

The present research is based on two expectations: a polyhedral oligomeric silsesquioxane (POSS) nano-cage can endow gel polymer electrolyte (GPE) with similar properties as can be accomplished with other inorganic nanoparticles; and the organic substituents at the cage corners of POSS are more compatible with GPEs. Therefore, POSS, as a hybrid modification filler, was added into GPE within a polymethyl methacrylate (PMMA) matrix. The results indicated that the amount of POSS addition was a critical factor for the ionic conductivity of prepared GPEs. When the POSS content was 7.5 wt%, the thermal stability was sufficient at the elevated temperature; the ionic conductivity of GPE reached 2.0 × 10⁻³ S cm⁻¹; the mechanism of conductivity followed typical Arrhenius behavior; the lithium ion transference number reached up to 0.33; the deposition/dissolution of lithium was highly reversible; the electrochemical stability window was high enough at 5.25 V and the compatibility with lithium electrolyte was satisfactory.