Oaks-derived activated carbon by trace alkali-induced catalytic steam activation for electrochemical capacitor applications

Abstract

With the aim of more efficiently using oaks resources, this study proposed a green and efficient strategy of trace KOH-induced catalytic activation to generate oaks-derived activated carbons (AC) for electrochemical capacitor applications. By studying the pore formation, trace KOH is found to be associated with mesopore formation and promotes the development of micropores in ACs, regulating the hierarchical structure of pores. Furthermore, trace KOH can enlarge the specific surface areas and change the surface functionalities of ACs. As the result, the obtained sample has a high specific surface area of 958 m2 g−1 and a total volume of 0.448 cm3 g−1. Evaluated as electrochemical capacitor (EC) electrode material, the obtained sample achieves a high specific capacitance of 157.5 F g−1 at a current density of 1 A g−1 and shows an excellent cycling performance with 97 % retention over 10,000 cycles at 2 A g−1. This work not only provides the mechanism understanding of the KOH-induced catalytic activation but also proves that the trace KOH-induced catalytic activation is a viable and green method for developing high-performance activated carbons for the demand of ECs in industrial applications.