Surface and Diffusion Charge Contribution Studies of Human Hair-Derived Heteroatom-Doped Porous Carbon Electrodes for Supercapacitors

Owing to the high specific surface area and adjustable pore size distribution, biowaste-derived activated carbon (AC) has lately aroused the interest of researchers in supercapacitor applications. Herein, we employ human hair-derived heteroatom-doped porous AC for supercapacitor applications. Electrochemical assessment of the as-synthesized material is examined in three distinct electrolytes, viz., basic (6 M KOH), neutral (1 M Na2SO4), and acidic (1 M H2SO4), and shows superior performance in 1 M H2SO4 implying its perfect compatibility in an acidic electrolyte. This finding is corroborated via surface and diffusion charge contribution analysis of the AC sample in different electrolytes. Comparing with 6 M KOH (37.5%) and 1 M Na2SO4 (67.5%), superior diffusion charge contribution is observed in the case of 1 M H2SO4 (79%) electrolyte at 20 mV/s that helps to achieve the highest specific capacitance of 274.5 F/g at 1 A/g. Moreover, the as-fabricated all-solid-state symmetric supercapacitor device delivered a remarkable energy density of 47.4 W h/kg at a power output of 1642.8 W/kg, as well as a long cycle life of 87% after 10 000 charge/discharge cycles. As a consequence, this astonishing finding paves the way for the use of various biowastes for a variety of applications for energy storage.

Automated summary

The study focuses on using human hair-derived heteroatom-doped porous activated carbon for supercapacitor applications, demonstrating superior performance in an acidic electrolyte. The activated carbon sample shows excellent diffusion charge contribution in the acidic electrolyte and achieves the highest specific capacitance. The fabricated all-solid-state symmetric supercapacitor device exhibits remarkable energy density and a long cycle life.