Futuristic Approach Towards Replacement of Aqueous Electrolyte with Solid Polymer Electrolyte for Supercapacitor Applications

Solid polymer electrolytes (SPEs) based on ionic liquid (IL) were created using poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) polymer mixed with 30 wt.% sodium thiocynate and varying weight ratios of EMIm-TCM ranging from 0 wt.% to 300 wt.%. The structural, electrical, thermal, morphological, and electrochemical features of the SPEs films, showing the effects of PVDF-HFP and the level of IL loading, have all been carefully examined. With the addition of IL, the mechanical qualities and mechanical stability of PVDF-HFP were enhanced, getting closer to the smaller usage for liquid electrolytes in energy devices. With the addition of 300 wt.% IL, the maximum ionic conductivity of 10 −3 S cm −1 was attained. Additionally, the presence of the amorphous region in the IL-based electrolyte supported the movement of the EMIm + and TCM − ions in the PVDF-HFP chains, as shown by polarized optical microscopy and the ionic transference number. Due to their strong ionic conductivity, good mechanical attributes, and potential for long-term use in electrical double-layer capacitor applications, the developed PVDF-HFP/NaSCN/EMIm-TCM complex-based SPEs are particularly promising, showing the specific capacitance of 10 Fg −1 .