Porous carbon materials derived from waste cotton stalk with ultra-high surface area for high performance supercapacitors

Abstract In recent years, porous carbon materials have gained attention as excellent electrode materials owing to their large specific surface area and good electrical conductivity to promote ion transport and electron transfer. Therefore, to realize their widespread application, it is of great significance to reduce the production cost of carbon materials. Hence, the preparation of carbon materials using cotton stalk has been proposed. In this study, we carried out the carbonization and activation of cotton stalk to prepare high-performance energy storage materials with different KOH/carbon mass ratios (0:1, 2:1, 3:1, and 4:1) at 600 and 800 °C. The cotton stalk-based carbon materials (CSCMs) prepared at the optimum pyrolysis temperature exhibited large specific surface area and good electrochemical properties. Therefore, the all-solid supercapacitor device assembled with gel electrolyte exhibited high rate capability (an energy density of 12.5 Wh/kg and a power density of 900 W/kg) and excellent stability. Thus, the proposed porous carbon materials derived from waste biomass cotton stalk for the preparation of high-performance supercapacitors have huge application prospects.