High-Performance Porous Carbon Electrode Materials Derived from Air Pre-oxidation of Anthracite Supplemented with KOH Activation for Supercapacitors

In this study, we report the development of a porous activated carbon electrode (PACE) material for supercapacitors, derived from anthracite carbonized at high temperatures in an argon atmosphere. Our approach involves a facile air pre-oxidation process, followed by KOH activation, to significantly enhance the material's specific surface area and porosity. The pre-oxidation treatment effectively increased the specific surface area to 1555.1 m 2 g −1 , resulting in a large number of micropores and mesopores. Moreover, this treatment effectively modulated the structure of small-to-medium-sized pores (2–4 nm) in the PACE samples, ensuring sufficient charge storage capacity and rapid electrolyte ion transport. The optimal sample, C-Pre-2h, demonstrated remarkable cycling stability, with 100% capacitance retention after 10,000 cycles, and a high specific capacitance of 272.1 F g −1 at 1 A g −1 . A symmetric supercapacitor based on C-Pre-2h exhibited a substantial energy density of 10.11 Wh kg −1 at 256 W kg −1 , alongside a high power density of 25,641 W kg −1 at 3.16 Wh kg −1 . This work presents a cost-effective porous carbon material with exceptional cycling stability and superior performance for supercapacitor applications. Graphical Abstract