Revisiting Charge Storage Mechanism of Reduced Graphene Oxide in Zinc Ion Hybrid Capacitor beyond the Contribution of Oxygen‐Containing Groups. (5th January 2022)

• Record Type: Journal Article
• Authors: Xu, Hai; He, Wenjie; Li, Zhiwei; Chi, Jiaxiang; Jiang, Jiangming; Huang, Kangsheng; Li, Shulong; Sun, Gengzhi; Dou, Hui; Zhang, Xiaogang
• Is Part Of: Advanced functional materials. Volume 32:Number 16(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-01-05
• Subjects: 3D printed electrode -- charge storage mechanism -- proton adsorption chemistry -- reduce graphene oxide -- Zn ion capacitor; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202111131
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Recently, developing matchable cathode materials of Zn ion hybrid capacitor still remains difficult owing to insufficient understanding of the charge storage behavior. However, most previous efforts are devoted to explain the effect of oxygen‐containing groups without paying attention to graphitic structure. Herein, the charge storage capability and electrochemical kinetics of reduce graphene oxide (rGO) nanosheets are optimized as a function of their surface properties. Beyond the contribution of oxygen‐containing groups, an extra contribution from the reversible adsorption/desorption of H + on carbon atom of rGO sheets is confirmed. Electrochemical analysis and density functional theory calculations reveal that H + induces disruption of π cloud in aromatic domain, accompanied by C sp 2 ‐sp 3 re‐hybridization and the distortion/restoration of graphitic structure. The optimal electrochemical performance with a specific capacitance of 245 F g ‐1 at 0.5 A g ‐1 with 53% retention at 20 A g ‐1 is achieved for rGO thermally treated at 200 ° C. As a proof‐of‐concept application, the 3D printed rGO electrode delivers a high areal capacitance of 1011 mF cm ‐2 and an energy density of 266 μWh cm ‐2 . The study is believed to broaden the horizons of proton adsorption chemistry and shed light on the design of novel electrode materials. Abstract : The charge storage capability and electrochemical kinetics of reduce graphene oxide nanosheets are optimized via tailoring their surface chemistry in Zn ion hybrid capacitor. Beyond the contribution of oxygen‐containing groups, the charge storage mechanism is highlighted with an extra contribution from the reversible adsorption/desorption of H + on carbon atom, accompanying C sp 2 ‐sp 3 re‐hybridization and the distortion of graphitic structure.