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

Abstract

In this work, we proposed a facile one-pot pyrolysis method to conveniently manufacture 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 conditions 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.

Keywords

• Hierarchical porous carbon
• Lignin
• Potassium citrate
• Supercapacitors