Electrochemical performance of potato-derived activated carbon: Effect of compressive stress

The progress in smart electronics and photonics has imposed a great need for the development of portable, flexible devices and systems for energy storage from sustainable and eco-friendly resources. In this work, we synthesize porous activated carbon (AC) from potato mash via hydrothermal process and H2O-steam activation and construct symmetrical supercapacitors with the potato-derived ACs as electrode material and 6 M KOH aqueous solution as electrolyte. The effects of the mass loading of the electrode material and compressive stress in a range of 1.69~6.92 MPa on the electrochemical performance of the supercapacitors are investigated. The experimental results reveal that increasing the compressive stress increases the specific capacitance of the supercapacitors and the diffusivity for ionic migration in the supercapacitors and causes the decreases of the IR drop, the series resistance and the intrinsic resistance. The method used in this work provides a feasible technique to increase the energy storage in supercapacitors.