Hierarchical S-doped porous carbon derived from by-product lignin for high-performance supercapacitors

Abstract

For the first time, hierarchical S-doped porous carbon was fabricated using sodium lignosulfonate as a carbon and sulfur precursor through a simple template technique. The obtained carbon has a high surface area (1054 m2 g−1), high pore volume (1.73 cm3 g−1), high sulfur content (2.9 wt%), and interconnected open macropores that can provide many storage sites, pseudocapacitance, and short transport paths for ions. The as-obtained S-PC-L-900 exhibits a high specific capacitance (328 F g−1) at 0.2 A g−1, excellent rate performance with 73% capacitance retention after a current density increasing from 0.5 to 20 A g−1 and cycling stability, with 97% capacitance retention after 10 000 cycles. Additionally, a symmetric supercapacitor based on S-PC-L-900 delivers a high energy density (6.9 W h kg−1) at 50 W kg−1