Blowing Agent-Induced Hierarchical Porous Carbon from Low-Quality Coal for High-Performance Supercapacitor

The rising demands for sustainability in the environment and energy lead to the design and development of energy storage devices with high energy and power density and hence the potential electrode materials. Tremendous interest has been shown in the sustainable and economical synthesis of porous carbon with high surface area. Hence, in this study, a series of hierarchical porous carbons were proficiently synthesized from Northeastern Indian low-quality subbituminous coal feedstock using NH4Cl as a blowing agent and KOH as pore inducing activation agent with hierarchical pores and high-surface area (1996 m2/g). The structural and physicochemical properties of the hierarchical porous carbon (HCK3) synthesized by blowing agent-induced activation exhibit significant specific capacitance of 190, 107, and 56 F/g in aqueous, organic, and ionic electrolytes, respectively. Furthermore, the maximum energy density and power density of HCK3-based symmetric supercapacitor are 22.4 Wh/kg and 17 kW/kg, respectively, demonstrating promising supercapacitor application prospects.