Effect of different activating agents on carbon derived from Tinospora cordifolia for EDLC application

Abstract

Abstract The effect of two activating agents namely phosphoric acid (H3PO4) and iron (III) chloride (FeCl3) is investigated, in activation of carbon obtained from Tinospora cordifolia. The structural and morphological properties of the synthesized activated carbons were investigated using X-ray diffraction, scanning electron microscopy, Raman spectroscopy, and Brunauer–Emmett–Teller analysis. A notable yield of ∼60 % of the activated carbons was obtained using a simple and cost-effective approach of chemical activation followed by the thermal activation method. The electrochemical properties of the activated carbons were studied for electric double-layer capacitor application. The electrochemical impedance spectroscopy, galvanostatic charge–discharge and cyclic voltammetry studies revealed superior charge transfer properties of the carbon activated with H3PO4. The capacitor comprising carbon activated with H3PO4 electrodes shows higher specific capacity of 58 F g−1 at 1 A g−1 than that of carbon activated with FeCl3 (37.5 F g−1). The optimized capacitor delivers superior power density and energy density of 2 kW kg−1 and 28.33 W h kg−1, respectively.