High-Performance Symmetric Supercapacitor Constructed Using Carbon Cloth Boosted by Engineering Oxygen-Containing Functional Groups

Carbon materials display appealing physical, chemical, and mechanical properties and have been extensively studied as supercapacitor electrodes. The surface engineering further allows us to tune their capability of adsorption/desorption and catalysis. Therefore, a facile and inexpensive chemical-acid-etching approach has been developed to activate the carbon cloth as an electrode for supercapacitor. The capacitance of the acid-etched carbon cloth electrode can approach 5310 mF cm–2 at a current density of 5 mA cm–2 with remarkable recycling stability. The all-solid-state symmetric supercapacitor delivered a high energy density of 4.27 mWh cm–3 at a power density of 1.32 W cm–3. Furthermore, this symmetric supercapacitor exhibited outstanding mechanical flexibility, and the capacity remained nearly unchanged after 1000 bending cycles.