Black Liquor and Wood Char-Derived Nitrogen-Doped Carbon Materials for Supercapacitors

Herein, we present a synthesis route for high-efficiency nitrogen-doped carbon materials using kraft pulping residue, black liquor, and wood charcoal as carbon sources. The synthesized nitrogen-doped carbon materials, based on black liquor and its mixture with wood charcoal, exhibited high specific surface areas (SSAs) of 2481 and 2690 m(2) g(-1), respectively, as well as a high volume of mesopores with an average size of 2.9-4.6 nm. The nitrogen content was approximately 3-4 at% in the synthesized nitrogen-doped carbon materials. A specific capacitance of approximately 81-142 F g(-1) was achieved in a 1 M Na2SO4 aqueous solution at a current density of 0.2 A g(-1). In addition, the specific capacitance retention was 99% after 1000 cycles, indicating good electrochemical stability.

Automated summary

In this study, a synthesis route for high-efficiency nitrogen-doped carbon materials was presented using kraft pulping residue, black liquor, and wood charcoal as carbon sources. The nitrogen-doped carbon materials synthesized from black liquor and its mixture with wood charcoal exhibited high specific surface areas and a high volume of mesopores. The nitrogen content in the synthesized materials was approximately 3-4 at%. These materials showed a specific capacitance of approximately 81-142 F g(-1) in a 1 M Na2SO4 aqueous solution at a current density of 0.2 A g(-1), with a specific capacitance retention of 99% after 1000 cycles, indicating good electrochemical stability.