Modulation of hierarchical porosity in metal-doping graphene/carbon hybrid aerogels for capacitive energy storage. (1st November 2022)

• Record Type: Journal Article
• Authors: Chao, Guojie; Wang, Dong; Wang, Yang; Zhang, Xu; Chen, Suli; Wang, Yufeng; Zong, Wei; Fan, Wei; Zhang, Longsheng; Liu, Tianxi
• Is Part Of: Journal of energy storage. Volume 55:Part A(2022)
• Publication Date: 2022-11-01
• Subjects: Supercapacitor -- Electrode material -- Carbon aerogel -- Hierarchical porosity; Energy storage -- Periodicals; Energy storage -- Research -- Periodicals; 621.3126
• DOI: 10.1016/j.est.2022.105445
• Languages: English
• ISSNs: 2352-152X

Abstract

Abstract: Carbon aerogels hold great promise as the electrode materials for energy storage owing to their desirable porous structures and specific surface areas. Here, we report a scalable approach for the preparation of Co-doped graphene/carbon hybrid aerogel (CGCA) with hierarchically porous structure through a dual cross-linking strategy. By adjusting the cross-linking structure of the hydrogel precursor, the porous structure of CGCA can be readily regulated and the specific surface area of CGCA can achieve 1217 m 2 g −1 . As a result, the CGCA samples not only manifest improved electrical conductivity, but also possess enhanced capacitance storage capacity. The optimized CGCA electrode displays a high specific capacitance of 371 F g −1 at 1 A g −1 and maintains a large specific capacitance of 57 % at 150 A g −1 . Meanwhile, the supercapacitor assembled with CGCA electrodes shows a high specific capacitance of 80 F g −1 at 0.5 A g −1 and good cyclic stability with a capacitance retention of 95 % after 10, 000 cycles. Moreover, the supercapacitor device can provide a high energy density of 11.1 Wh kg −1 at a power density of 250 W kg −1 . The superior energy-storage behaviors of CGCA make them promising electrode materials for high-performance supercapacitors. Graphical abstract: Benefited from the dual cross-linking effect from cobalt ions and graphene oxides, the cobalt-doped graphene/carbon hybrid aerogel (CGCA) exhibits desirable hierarchical porosity and thereby enhanced capacitive energy storage than the graphene/carbon aerogel (GCA) and pure carbon aerogel (PCA). Unlabelled Image Highlights: A facile strategy to construct the metal-doped graphene/carbon hybrid aerogels (CGCA) is reported. The dual cross-linking effects from metal ions and graphene oxide can regulate the pore structures of CGCA. The CGCA electrodes exhibit high capacitance of 371 F g -1 at 1 A g -1, with good rate performance and cycle stability. The supercapacitors with CGCA electrodes can achieve a high energy density of 11 Wh kg -1 at a power density of 250 W kg -1 .