Electrochemical properties of activated carbon from waste coffee grounds with hydrothermal-microwave radiation technique

Coffee is the most popular drink consumed by millions of people around the world every day. Global coffee production creates over 20 million tons of waste per year. There is trash, largely from the result of coffee brewing and instant coffee, readily available in vast amounts at low price or without value called waste coffee grounds. This study aimed to investigate the electrochemical properties of activated carbon made from waste coffee grounds. The activated carbon (AC) from waste coffee grounds increased porosity by KOH through the Hydrothermal-Microwave radiation technique at various times including, the surface area, the amount of microporous and mesoporous. The AC from waste coffee grounds was characterized by different techniques. Electrode preparation and electrochemical study were set up for measuring and evaluating the electrochemical properties of AC from the waste coffee grounds. The AC-20 min showed a high specific capacitance of 115 F/g at 1 A/g and 68 F/g at 30 A/g from the discharge appearance. The working electrode constructed from activated carbon waste coffee grounds in nickel foam gave an energy density and power density of 19.07 Wh/kg and 15,147 Wk/g, respectively. The effectiveness of the AC from waste coffee grounds in this research showed viability for fabricating energy materials.