Performance of Supercapacitor Using Carbon Electrode Prepared via Microwave Activation of Japanese Distilled Liquor Waste

Abstract

ABSTRACT Japanese distilled liquor (Shochu) is a widely produced alcoholic beverage in the Kyushu region of Japan. Our research group is developing inexpensive electrode material for supercapacitors (SCs) using waste generated during shochu production. In a previous study, shochu waste was carbonized and activated in an electric furnace; however, this process involved long production times and high running costs. To address these limitations, this study investigated the use of microwave activation as a faster and more cost-effective alternative. Activated carbon (AC) was fabricated from carbonized shochu waste mixed with potassium carbonate in a 1:3 weight ratio. Microwave power was set to 800 W, and the activation time was varied. The performance of the AC samples was evaluated by analyzing surface morphology, specific surface area, and pore volume, along with measurements of specific capacitance and charge-transfer resistance. The results revealed a maximum specific surface area of 1,063 m ² /g and a specific capacitance of 229 F/g in 0.5 mol/L KOH at an activation time of 9 minutes. Additionally, microwave activation reduced power consumption costs by approximately 61.9% compared to activation using an electric furnace. Keywords: Supercapacitor; shochu waste, activated carbon, microwave activation