Hybrid electrolyte SiW9MoV2/rGO/SPEEK for solid supercapacitors with enhanced conductive performance

Abstract

To improve the proton conductive performance of heteropoly acids, a novel proton-conducting hybrid electrolyte SiW9MoV2/rGO/SPEEK was prepared by a simple and effective method based on sulfonated polyether ether ketone (SPEEK), H6SiW9MoV2O40 (SiW9MoV2) and reduced graphene oxide (rGO) in this work. This hybrid material was characterized by IR, TEM and XRD. Electrochemical impedance spectroscopy shows the obtained SiW9MoV2/rGO/SPEEK electrolyte exhibits an appreciable proton conductivity of 1.07 × 10−2 S cm−1 at 16 °C and 70% relative humidity, which increases with higher temperature, and the activation energy for proton conduction of this hybrid film is 17.82 kJ mol−1. The proton conduction is speculated to be the mixing of Grotthuss mechanism and Vehicle mechanism that accelerate the proton mobility in the hybrid electrolyte. This work lays a foundation in the field of HPAs-based separator films for proton exchange membrane devices and solid supercapacitors.