Supercapacitors based on Citrus aurantifolia fruit

Abstract

Rapid global economic growth, population growth, and the dwindling availability of fossil fuels are driving the need for a new generation of energy storage technologies that are efficient, economical, and sustainable to support the use of renewable energy, one of which is the supercapacitor. This study explores lime (Citrus aurantifolia) as a source of activated carbon, an activation agent, a natural electrolyte, and a natural separator in supercapacitors. Lime peel is processed into activated carbon through chemical activation using lime juice as the activating agent. The pyrolysis process was conducted at various temperatures of 600°C, 700°C, and 800°C in a N₂ gas flow. SEM results showed that LP-600 is dominated by micropores, which contribute to an increase in. specific surface area. EDX analysis indicates that LP-600 has the highest carbon content, at 94.72%. Testing of electrochemical properties showed that LP-600 exhibits good performance, with specific capacitance values of 20.35 Fg^-1 and 2.48 Fg^-1 based on the cyclic voltammetry and galvanostatic charge–discharge methods. The results of this study indicate that lime has potential as an alternative carbon source, an activation agent, and a natural electrolyte in the development of sustainable and environmentally friendly supercapacitors. Based on the results obtained, the optimal pyrolysis temperature in this study was 600°C.