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.