Longan Leaves biomass-derived renewable activated carbon materials for electrochemical energy storage

Biomass-based energy conversion and storage applications have proven to be the most effective technology for practical and sustainable applications. However, their further development was hindered by poor electrode performance. Naturally, abundant biomass is a green alternative carbon source with many desirable properties. This study presents a relatively easy approach for the synthesis of activated carbon-based electrode materials derived from natural biomass with an emphasis on supercapacitor applications. The selected biomass waste is Longan leaves. The precursor was converted into activated carbon through ZnCl2 impregnation at three different concentrations in high-temperature pyrolysis. All activated carbon confirmed a good amorphous structure. Furthermore, oxidative compounds were also found to have an effect on their electrochemical properties. supercapacitor cells prepared in a two-electrode system exhibit high electro-capacitive properties with a specific capacitance of 169.83 F g−1 at a constant current density of 1.0 A g−1 in an aqueous electrolyte of 1 M H2SO4. Furthermore, the optimum energy density was found in LF0.5 samples as high as 19.04 Wh kg−1 at a maximum power density of 124.37 W kg−1.