Characterization and capacitive performance assessment of potato peels derived salt-induced porous carbons

Carbons obtained from biomass are green alternative and have tremendous potential to substitute energy expensive pyrolyzed carbons. However, development of efficient processes to develop porous structure into hydrochar is still a challenge. Herein, an efficient, cheaper, and scalable and green method is reported to produce carbon materials which were obtained from abundant biowaste (potato peels). The carbon material was prepared through two steps procedure; hydrothermal carbonization (180 °C) followed by thermal activation with salt (ZnCl 2 /LiCl) at various temperatures (600–850 °C). Carbon material obtained at 850 °C (Cpp 8 ) was found mesoporous in nature and possess surface area of 314 m 2 /g and unsaturated carbon chains/aromatic moieties. To investigate the performance of obtained porous carbon, an electrode was fabricated using copper film as support and polyaniline as binder and investigated for impedance and capacitive measurements using three electrode system. The minimum semicircle curve for Nyquist equation was observed for Cpp 8 which shows good conductivity with less resistive nature with respect to all other materials. Gravimetric and volumetric capacitance for Cpp 8 were calculated under three electrode system using H 2 SO 4 (0.5 M) as electrolyte and found to be 603 F g −1 . It may be concluded that environmentally friendly salt mixture (ZnCl 2 /LiCl) can induce mesopores in biomass-derived hydrochar. The materials showed good capacitance and can also be used as substitute of activated carbon in other applications.