RGO-templated lignin-derived porous carbon materials for renewable high-performance supercapacitors

• Published in: Electrochimica acta Vol. 353; p. 136482
• Main Authors: Jiang, Can, Wang, Zuhao, Li, Jiaxiong, Sun, Zhijian, Zhang, Yunfei, Li, Liang, Moon, Kyoung-Sik, Wong, Chingping
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.09.2020; Elsevier BV
• Subjects: Aerogels; Carbon; Carbonization; Electrode materials; Flux density; Graphene; High temperature; Hydrogels; Hydrothermal reactions; Industrial wastes; Lignin; Porous carbon materials; Porous materials; Quinones; Reagents; Reduced graphene oxide; Reducing agents; Structural hierarchy; Supercapacitors; Supercapacitors; Lignin; Reduced graphene oxide; Porous carbon materials
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2020.136482

Porous carbon materials are considered as one of the most promising electrode materials of supercapacitors. However, it is inevitable to use an expensive and high-polluting activation treatment for obtaining porous structure. Herein, we reported a scalable and sustainable approach to fabricate lignin-derived porous carbon materials by combining hydrothermal reaction and high-temperature carbonization without using any chemical or physical activating reagents. During the hydrothermal reaction, industrial waste lignin as a green reducing agent deoxidized graphene oxide (GO) effectively, while reduced GO (RGO) hydrogels as 3D templates transitioned lignin molecules from ellipsoidal to disk-like conformation via non-covalent interactions and orderly aligned them on the surface of RGO nanosheets. Through this way, the intermediate products, lignin reduced GO aerogels (LRGOs), delivered superior pseudocapacitive performance caused by the reversible phenol-quinone structural transition of lignin molecules. Results indicated a highly positive correlation between the pseudocapacitance of LRGOs and the reduction degree of RGO. After carbonization, the carbonized LRGOs (C-LRGOs) presented a hierarchical porous structure and the resulted high specific surface area rendered the material an ideal electrical double layer capacitive behavior showing high specific capacitance (330 F g−1 at 1 A g−1), high energy density (11.3 Wh kg−1) at a power density of 254 W kg−1, as well as reliable cycle performance. [Display omitted] •Waste lignin can deoxidate graphene oxide by hydrothermal reaction effectively.•RGO as 3D template regulates lignin molecules to form disc-like conformation.•Lignin/RGO aerogels show pseudocapacitance which depends on the reduction of GO.•Carbonized lignin/RGO aerogels form porous structure by the pyrolysis of lignin.•Carbonized Lignin/RGO aerogels show high energy density and long cycle life.