Exploring the Connection Between the Structure and Activity of Lignin-Derived Porous Carbon Across Various Electrolytic Environments

Porous carbon holds great potential for application in supercapacitors due to its rich pore structure and high specific surface area. In this research, lignin served as the starting material for the production of lignin-derived carbon materials via a carbonization-activation process. The resulting porous carbon materials underwent rigorous characterization using SEM, BET, Raman, XRD, and XPS to uncover their morphological and structural intricacies. Notably, the optimal product, achieved with a mass ratio of lignin to KOH and KCl at 1:2:0.5 and activation temperature at 700 °C, emerges as an excellent electrode material for high-performance supercapacitors. This superior carbon material boasts a remarkable specific surface area of 2730 m² g^-1, demonstrating an electrochemical capacitance up to 406 F/g at 1 A/g, its high performance surpasses many existing carbon materials. To further investigate the potential application of ELC in electric double-layer capacitors, the electrochemical properties of ELC in 6 M KOH, 1 M Na₂SO₄, and 1 M Et₄NBF₄/PC electrolytes were investigated, the reasons for the differences in ELC's electrochemical performance in different electrolytes are discussed and analyzed in detail, and the advantages and disadvantages of ELC's performance in capacitor devices of different systems are compared and analyzed. This was performed to compare the electrochemical performance of ELC and commercial YP-50F capacitor carbon in an electric double-layer capacitor, and to investigate the potential application of ELC.