Facile Synthesis of Porous Carbon Via Self‐Activation of Potassium Acetate for High‐Performance Supercapacitor Electrodes with Excellent Cyclic Stability

The capacitance of an electric double‐layer capacitor (EDLC) is largely determined by the surface area and the electrical conductivity of the electrode material. To enhance the performance of EDLCs, a separate activation procedure is commonly used to increase the porosity of the electrode. A facile and scalable method of producing highly porous carbon electrodes for high‐performance supercapacitors without a separate activation procedure via simple thermal treatment of potassium acetate is reported. Potassium acetate‐derived carbon (PAC) exhibits a high specific surface area of 1704 m 2 g −1 and superior electrical conductivity of 22 950 S cm −1 without further treatment. When used for EDLC electrodes, PAC displays a high specific capacitance of 195 F g −1 at 0.5 A g −1 and excellent cyclic stability with capacitance retention of 99.0% over 80 000 charge/discharge cycles. Carbonization and simultaneous self‐activation of PAC demonstrates a facile and efficient method of producing carbon electrodes with a high surface area without an additional activation procedure, which provides an efficient solution for producing high‐performance supercapacitor electrodes at low cost.