Enhanced Electrochemical and Dielectric Properties of PVDF‐HFP/Sodium Thiocyanate Polymer Electrolyte for High‐Performance EDLC Applications

ABSTRACT PVDF‐HFP‐based solid polymer electrolytes have attracted interest for energy storage applications, but a major drawback remains their comparatively low ionic conductivity. To close this gap, the current study examines how adding activated carbon (AC) and NaSCN might improve the electrochemical performance of PVDF‐HFP‐based electrolytes. The maximum ionic conductivity of PVDF‐HFP films doped with 30 weight percent NaSCN was 5.12 × 10 −5 S cm −1 , which was further enhanced by adding AC to the polymer‐salt matrix. The uniqueness of AC as an efficient Addition was highlighted by the greatly improved conductivity of 4.44 × 10 −4 S cm −1 in the optimized composition with 1 weight percent AC. Strong interactions and homogeneous dispersion within the polymer matrix were verified by structural and morphological investigations utilizing FTIR and polarized optical microscopy. Electrochemical studies revealed a high ionic transference number of 0.9 and a wide electrochemical stability window of 4.1 V. Furthermore, an electric double‐layer capacitor fabricated using the optimized electrolyte demonstrated specific capacitances of 93.40 F/g (CV) and 86.54 F/g (EIS). These findings demonstrate that ac incorporation significantly enhances ionic conductivity and overall performance, making the developed electrolyte a promising candidate for advanced energy storage devices.