Flexible Carbon Cloth Supercapacitors with High Power and Energy Densities

Abstract

Commercially available carbon cloths (CCs) are promising candidates to construct flexible and wearable electronics. Herein, post‐treated CCs are employed to construct flexible supercapacitors (SCs). CCs are first activated in KOH solution and subsequently thermally annealed, resulting in their unique porous microstructure and a wide potential window up to 2.2 V. Using these binder‐ and current‐collector‐free CCs as the capacitor electrodes, a high‐performance and flexible electrical double‐layer capacitor is constructed. In 1 m KOH aqueous solution, its specific capacitance of as high as 1 967.0 mF cm−2 is obtained at a current density of 30 mA cm−2. Moreover, it exhibits excellent capacitance retention and delivers both high energy density (e.g., 93.38 W h kg−1 at a power density of 3 890 W kg−1) and high power density (e.g., 12 850 W kg−1 at an energy density of 12 W h kg−1). Such binder‐free, easy‐assembling, scalable flexible SCs are thus promising for miniaturized electronic industries in the future.