Preparation of sodium lignosulfonate-based porous carbon and its application to supercapacitors

Abstract

Supercapacitor is a kind of energy storage device between secondary battery and physical capacitor, which has the advantages of fast charging and discharging speed, high power density and excellent cycle stability. Compared with combustion batteries, the energy density of supercapacitors is low and needs to be further improved. The electrochemical performance of supercapacitors mainly depends on the electrode materials. Porous carbon (PCs) materials are currently one of the most widely used supercapacitor electrode materials due to their high specific surface area, good chemical stability and low cost. The best morphology of the sample was obtained when the temperature was 800 ℃ and the alkali carbon ratio was 1:1. Specimen PC800-1 has the largest specific surface area of 1894.97 m²g⁻¹. In the three-electrode test system, the specific capacitance of sample PC800-1 is as high as 217.5 F g⁻¹ at 0.5 A g⁻¹, and the multiplicity performance is 46.1% at 20 F g⁻¹. In the two-electrode test system, the sample has a specific capacitance of 115 F g⁻¹ at 0.5 A g⁻¹, an energy density of 13.33 Wh kg⁻¹, and a power density of 499.88 W kg⁻¹. This green and efficient synthesis of sodium lignosulfonate-based is a promising alternative strategy for the production of carbon-based supercapacitors.