Improved Electrochemical Performance of Activated Carbon Nanofibers for Supercapacitor Applications in Redox Additive Electrolytes

ABSTRACT The choice of suitable materials and additives along with their effective integration, plays a key role in enriching the supercapacitor behavior. Among the various emerging materials, carbon‐based electrodes have garnered substantial focus toward their potential in energy field. Recently, redox additives have been investigated as superior alternatives to conventional aqueous electrolytes. The current work deals with the development of activated carbon nanofiber with KOH and NaHCO 3 as chemical activating agents and explores their usefulness as a supercapacitor in redox additive. The NaHCO 3 activated carbon nanofiber (CNF) achieved the specific capacitance of 399 and 1482 F/g at 3 A/g in 1 M H 2 SO 4 without and with hydroquinone, respectively. Both XPS and EDAX analyses revealed the presence of heteroatoms that too participates in acidic electrolyte during half‐cell analysis. In hydroquinone incorporated acidic electrolyte, the NaHCO 3 ‐activated CNF‐derived symmetric supercapacitor realized 25.6 Wh/kg as the energy density at 3 A/g and 80% capacitance maintained after 5000 rounds of GCD at 10 A/g.