Highly graphitic porous carbon prepared via K2FeO4-assisted KOH activation for supercapacitors

Abstract

Highly graphitic porous carbon was derived from kelp biomass and prepared using KOH as the main activating agent with K₂FeO₄ as the assisting activated agent for supercapacitor applications. The optimum K₂FeO₄ mass in the total activating agent and temperature were investigated. The characterization results showed porous sheet carbon with a high specific surface area of 2868 m² g⁻¹ and a low I_D/I_G of 0.909. It delivered an excellent specific capacitance of 438 F g⁻¹ at 0.5 A g⁻¹. In addition, the assembled supercapacitor device reached the highest energy density of 19.9 W h kg⁻¹ with a power density of 398 W kg⁻¹.