Hierarchical porous carbon derived from lignin for high performance supercapacitor

Abstract Hierarchical porous carbons (HPCs) were prepared from lignin (denoted as LAC) via traditional carbonization-activation method. The resulting LAC prepared from lignin was composed with macroporous cores, mesoporous and microporous channels. The preparation parameters were discussed in detail in this paper. The LAC activated with a KOH–carbon ratio of 4:1 at 800 °C displayed the highest BET specific surface area of 3775 m2 g−1. The unique hierarchical structure of LAC provided LAC with favorable ion transportation paths and high ion-accessible surface area, which enhanced the electrochemical performance of LAC as electrode material of supercapacitor. The specific capacitance of LAC was as high as 286.7 F g−1 at a charge–discharge current density of 0.2 A g−1 in 6 mol L−1 KOH, and still retained 207.1 F g−1 at a high charge–discharge current density of 8 A g−1.