Functional‐Group Modification of Kraft Lignin for Enhanced Supercapacitors. Issue 10 (18th March 2020)

• Record Type: Journal Article
• Authors: Zhou, Bingjie; Li, Jing; Liu, Wei; Jiang, Hanmei; Li, Shaobo; Tan, Luxi; Dong, Lichun; She, Lan; Wei, Zidong
• Is Part Of: ChemSusChem. Volume 13:Issue 10(2020)
• Page Start: 2628
• Page End: 2633
• Publication Date: 2020-03-18
• Subjects: biomass -- energy storage -- lignin -- quinones -- supercapacitors; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.201903435
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: Recent efforts to improve the capacitances of Kraft lignin (KL) in supercapacitors have mainly focused on screening KL substrates, which could either compensate the poor conductivity of KL or directly contribute to the capacitance. However, increasing the pseudocapacitance contributed by KL itself, through hydroquinone/quinone redox cycles, remains a challenge, owing to the roughly fixed content of hydroquinone species in natural KL. In this study, the capacitance of KL is greatly improved by using a functional‐group modification strategy in which methoxy groups in KL are selectively converted into phenolic hydroxy groups, which facilitate the formation of additional hydroquinone moieties and thus lead to higher pseudocapacitances. The oxidized KL materials show up to 25.6 % enhancement of the phenolic hydroxy content in comparison to raw KL, which results in 21.9 % capacitance improvement from 322 to 390 F g −1 at 0.5 A g −1 in an acidic system. Abstract : Expertly Krafted : A functional‐group modification strategy is found to improve the capacitance of Kraft lignin (KL) in supercapacitors. Methoxy groups in KL are converted into phenolic hydroxy groups, in turn forming additional hydroquinone species. A 25.6 % enhancement in phenolic hydroxy content in KL thereby leads to 21.9 % capacitance improvement at 0.5 A g −1 in an acidic system.