Valorization of lignin waste: high electrochemical capacitance of lignin-derived carbons in aqueous and ionic liquid electrolytes

Sangchoom, Wantana; Walsh, Darren A.; Mokaya, Robert

Abstract

This report describes the utilization of waste lignin-derived activated carbons (LACs) as high-energy/high-power electrode materials for electric double layer capacitors(EDLCs). The influence of carbon-pore structure on the capacitance of the LACs in two aqueous (H2SO4 and KCl) and two ionic liquid (1-ethyl-3-methylimidazolium ethylsulfate, [EMIm][EtSO4], and 1-butyl-3-methylimidazolium tetrafluoroborate, [BMIm][BF4]) electrolytes is evaluated. In EDLCs containing aqueous H2SO4 as electrolyte, the LACs exhibit specific capacitances of up to 223 F/g and good cycling stability, with energy density of 5.0 Wh/kg at a power density of 200 W/kg. EDLCs containing KCl achieved a specific capacitance of 203 F/g, and energy density of 7.1 Wh/kg at a power density of 510 W/kg. The specific capacitances of the LACs in [EMIm][EtSO4] and [BMIm][BF4] were up to 147 F/g and 175 F/g, respectively. The energy density in the IL electrolytes, is up to 25 Wh/kg at power density of 500 W/kg, and 16.4 Wh/kg at 15 kW/kg. We demonstrate that the electrochemical performance of the LACs depends not only the surface area and pore size, but also on the pore-wall thickness.

Citation

Sangchoom, W., Walsh, D. A., & Mokaya, R. (2018). Valorization of lignin waste: high electrochemical capacitance of lignin-derived carbons in aqueous and ionic liquid electrolytes. Journal of Materials Chemistry A, 6(38), (18701-18711). doi:10.1039/c8ta07632d. ISSN 2050-7488

• Journal Article Type: Article
• Acceptance Date: Sep 7, 2018
• Online Publication Date: Sep 7, 2018
• Publication Date: Oct 2, 2018
• Deposit Date: Oct 5, 2018
• Publicly Available Date: Sep 8, 2019
• Journal: Journal of Materials Chemistry A
• Print ISSN: 2050-7488
• Electronic ISSN: 2050-7496
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 6
• Issue: 38
• Pages: 18701-18711
• DOI: https://doi.org/10.1039/c8ta07632d
• Keywords: Renewable Energy, Sustainability and the Environment; General Materials Science; General Chemistry
• Public URL: https://nottingham-repository.worktribe.com/output/1148806
• Additional Information: This document is Similarity Check deposited; : Supplementary Information; : Darren A. Walsh (ORCID); : Robert Mokaya (ORCID); : Single-blind; : Received 6 August 2018; Accepted 7 September 2018; Accepted Manuscript published 7 September 2018; Advance Article published 24 September 2018; Version of Record published 2 October 2018