Immense Microporous Carbon@Hydroquinone Metamorphosed from Nonporous Carbon As a Supercapacitor with Remarkable Energy Density and Cyclic Stability

Abstract

We report transformation of a cost-effective nonporous carbon (NC) to an immense microporous carbon (IMC) employing a simple chemical activation route at 750 °C. N2 adsorption/desorption experiments revealed a remarkable increase in BET surface area (80–3030 m2 g–1) for successor nanomaterial (IMC) in comparison to precursor nanomaterial (NC) presumably due to enhanced accessibility of reaction surface area on carbon material for oxidants to react. In consequence, 250 times specific capacitance enhancement (2.5–605 F g–1 at 0.5 A g–1 current density) was observed in 2 M H2SO4 using a three-electrode configuration. Further, a massive specific capacitance of 1177 F g–1 with a remarkable energy density of 163 Wh kg–1 has been achieved by addition of hydroquinone in electrolyte with IMC (IMC@H2Q) employing a two-electrode configuration. Notably, a simple electrode potential dependent chemical reversibility for hydroquinone redox chemistry in the long term cyclic experiment (95% capacitance retention after 500...