Fabrication of graphitized carbon fibers from fusible lignin and their application in supercapacitors

Abstract

Lignin-based carbon fibers (LCFs) with graphitized structures decorated on their surfaces were successfully prepared using simultaneous catalyst loading and chemical stabilization of melt-spun lignin fibers, followed by quick carbonization functionalized as catalytic graphitization. This technique not only enables surficial graphitized LCF preparation at a relatively low temperature of 1200 °C but also avoids additional treatments used in conventional carbon fiber production. The LCFs were then used as electrode materials in a supercapacitor assembly. Electrochemical measurements confirmed that LCF-0.4, a sample with relatively low specific surface area of 89.9 m2 g−1, exhibited the best electrochemical properties. The supercapacitor with LCF-0.4 had a specific capacitance of 50.2 F g−1 at 0.5 A g−1, power density of 644.9 kW kg−1, energy density of 15.7 Wh kg−1, and capacitance retention of 100% after 1500 cycles even without activation.