The performance of supercapacitor electrodes developed from chemically activated carbon produced from waste tea.

Highly microporous and mesoporous activated carbons were produced from waste tea for application as supercapacitor electrodes, utilising a chemical activation method involving treatment with either K 2 CO 3 or H 3 PO 4 . The area, pore structure characteristics and surface functionality of the activated carbons were evaluated to investigate the influence on electrochemical performance. The performance of the activated carbons as supercapacitor electrodes was tested by cyclic voltammetry (CV), impedance spectroscopy (EIS) and galvanostatic charge–discharge (GCD) measurements, in an aqueous electrolyte. The results showed that the pore structure and type of the activated carbon have significant impact on the supercapacitor performance. Both waste tea-based activated carbon electrodes showed good cyclic stability. However, despite its lower specific surface area the highly microporous activated carbon produced with K 2 CO 3 , exhibited much better capacitive performance than that of the mesoporous activated carbon produced with H 3 PO 4 . [ABSTRACT FROM AUTHOR]