Sustainable supercapacitors of sulfur-doped carbon from environmentally friendly sodium lignosulfonate impregnated with bacterial cellulose

The use of sustainable natural sources to fabricate porous carbon materials has garnered significant interest in energy storage. This study proposes a method for synthesizing sulfur-doped porous carbon (S‑carbon) materials via the carbonization of bacterial cellulose (BC) impregnated with sodium lignosulfonate (LS), which functions as a renewable source of both carbon and sulfur, eliminating the need for external activation processes. The carbonization process yielded S‑carbon with a notable sulfur content of 1.4 % and a high specific surface area of 650 m2/g. Transmission electron microscopy (TEM) images reveal fibrous carbon structures with mesopores and micropores in the S‑carbon material. Electrochemically, S‑carbon exhibited an impressive specific capacitance of 272.6 F g−1 at a current density of 1 A/g and demonstrated outstanding cycling stability, retaining 86 % of its capacitance after 5000 cycles at a current density of 6 A/g in a 3 M KOH electrolyte. The development of sulfur-doped fibrous carbon from BC-LS offers promising potential as a sustainable electrode material for supercapacitors.