Phosphoric acid modified starch as a binder for supercapacitor electrode in 3 M H2SO4

Starch derived from waste cassava peel was modified to form a binder and compared with the conventional PVDF binder. The binders and the electrodes fabricated by these binders were characterized by SEM, BET, XRD, FTIR, and electrochemical tests (CV, GCD, EIS, stability). The XRD spectra show sharp peaks of the modified starch (phosphoric acid modified starch – PS). These peaks indicate a level of crystallinity in modified starch as compared to the native cassava starch – CS. The BET analysis revealed that there was relatively high pore blockage with PVDF as compared to the synthesized binder. The electrochemical results indicate the untapped potential of modified starch binders in supercapacitor applications. The electrodes fabricated with the modified starch binder exhibits a high performance in terms of specific capacitance and cycling stability in 3 M H2SO4 electrolyte. Electrodes fabricated with PS shows capacitance value of 67.5 F/g as against 30.25 F/g for PVDF. Considering the unique properties and abundance of starch, this material will be a sustainable approach to supercapacitors binders. This work solved the hydrophilicity and swelling problem of starch to be efficiently used as supercapacitor electrode binder in aqueous H2SO4 electrolyte.