Sustainable Porous Carbons with Ultrahigh Specific Surface Areas for High-performance Supercapacitors

Abstract

Waste biomass residues are prospective precursors for the preparation of sustainable porous carbons. In this work, we used the residues from Lonicera japonica Thunb and Ligusticum chuanxiong Hort to prepare porous carbons with ultra-high specific surface area (> 3000 m2 g−1), which deliver excellent capacitive performance for electrochemical double-layer capacitor. Porous carbon derived from Ligusticum chuanxiong Hort displays a specific capacitance of 314.4 F g−1 (1 A g−1) in three electrode system. The energy density of Ligusticum chuanxiong Hort-based symmetric supercapacitor reaches 8.4 Wh kg−1 at the power density of 519 W kg−1 in 6 M KOH. The cell remains a high energy density of 5.1 Wh kg−1 at an increased power density of 10.8 kW kg−1. Our work indicates that the waste biomass residues are promising and competitive precursors for the preparation of ultrahigh specific surface area porous carbons for supercapacitor application.