open access

https://hdl.handle.net/2115/97404

Development of softwood kraft lignin-based conductive carbon for sustainable supercapacitor

英語

supercapacitor

2025-02-04

Walter de Gruyter

Holzforschung

79(2-3)

168-176

Electric double-layer capacitors (EDLCs) are promising devices for sustainable energy storage. However, EDLC components, such as separators and electrodes composed of activated carbon and conductive additives, are derived from fossil resources. To reduce this dependency, an EDLC was assembled using a separator and electrodes derived from hardwood kraft lignin, while still relying on fossil-based carbon black (CB) as the conductive additive. To achieve more sustainable EDLCs, this study developed all the conductive carbon, separator, and electrodes from softwood kraft lignin (SKL). When SKL was carbonized at 900 degrees C, it showed poor electrical conductivity and was unsuitable as a conductive additive. The carbon structures became more ordered with higher temperatures, and SKL-carbons prepared at 1,300-2,000 degrees C showed comparable conductivity to CB. The EDLCs with 1 wt % of these SKL-carbons exhibited higher capacitance and energy density than reference EDLCs with 1 and 5 wt % CB. Furthermore, a turbostratic (T) structure formed at 2,500 degrees C, enhancing conductivity and EDLC performance. SKL-carbon prepared at 2,800 degrees C exhibited a graphite structure in addition to the T structure, achieving the highest conductivity (0.54 S cm(-)1), but the resulting EDLC showed low power density. Thus, SKL-carbon prepared at 2,500 degrees C was the best conductive additive for EDLCs.

学術雑誌論文

Accepted Manuscript

0018-3830