In the present work, boron-doped multicomponent gel polymer electrolytes composed of host polymer, sulfonated polysulfone (SPSU) and the additives; ionic liquid, 1-ethyl-3-methyl-imidazolium tetrafluoroborate (IL), H3BO3, polyphosphoric acid (PPA) were prepared. Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) techniques were used to characterize the sulfonated polysulfone-based electrolytes. Ion conductivity of these gel electrolytes were studied by dielectric impedance analyzer within the temperature from -20 to 100 degrees C. The ionic conductivity of the SPSU-5IL-1PPA and SPSU-5IL-1H(3)BO(3)-1PPA were measured as 4.8 x 10(-3) and 9 x 10(-4) S cm(-1), respectively. Supercapacitor having activated carbon-based composite electrode and electrolyte was constructed with the configuration: Al/C/electrolyte/C/Al. The electrochemical properties and ion transfer characteristics of the supercapacitor were investigated by the cyclic voltammetry (CV). Galvanostatic charge-discharge experiments exhibited good electrochemical reversibility and produced a specific capacitance value of 120 F g(-1) at 1 A g(-1). The symmetric supercapacitor system was retained almost 85% of its initial activity after 1000 cycle.