A facile synthesis of hierarchical porous carbon derived from renewable lignin for high-performance supercapacitor

In this work, we proposed a facile one-pot pyrolysis method to conveniently manufac-ture lignin-derived carbon materials with graded porous construction for use in supercapacitors. The renewable lignin was selected as precursor, while the potassium citrate was used as a pore -forming agent. The properties of the prepared lignin-derived carbon (LAC) and the performance for supercapacitor application were thoroughly evaluated. The LAC at optimal preparation condi-tions shows a layered porous structure with a large specific surface area of 3174 cm2 g-1 and pore volume of 2.796 cm3 g-1, where the specific capacitance reach to 241 F g-1 at 1 A g-1 scan rate in 6 M KOH electrolyte solution. At the same time, the specific capacitance remains at 220 F g-1 even at an excessive scan velocity of 20 A g-1, while the capacitance retention is still close to 91.3%. The capacitance retention rate is stable above 95% after 10,000 charge/discharge cycles, which shows the desired long-time stability. All these results demonstrate the outstanding properties of the new prepared LAC material and the considerable application potential in the field of electrical energy storage. & COPY; 2023 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).