Microwave-assisted synthesis of CoAl-layered double hydroxide/graphene oxide composite and its application in supercapacitors

• Published in: Electrochimica acta Vol. 85; pp. 248 - 255
• Main Authors: Fang, Jihong, Li, Min, Li, Qianqian, Zhang, Weifeng, Shou, Qingliang, Liu, Fu, Zhang, Xiaobin, Cheng, Jipeng
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15.12.2012; Elsevier
• Subjects: Agglomeration; Applied sciences; Capacitance; Capacitors. Resistors. Filters; Chemistry; Coal and derived products; CoAl-layered double hydroxide; Current density; Electrical engineering. Electrical power engineering; Electrochemical capacitance; Electrochemical impedance spectroscopy; Electrochemistry; Energy; Exact sciences and technology; Fuels; General and physical chemistry; Graphene; Graphene oxide; Hydroxides; Microwave-assisted reflux method; Nanocomposites; Nanomaterials; Nanostructure; Oxides; Various equipment and components; Graphene oxide; CoAl-layered double hydroxide; Microwave-assisted reflux method; Electrochemical capacitance; Electrolytic capacitor; Microwave heating; Composite material; Operating conditions; Layered double hydroxide; Coal; Supercapacitor; Capacitance; Chemical synthesis; Application
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2012.08.078

[Display omitted] ► CoAl-layered double hydroxide/graphene oxide powders as supercapacitor materials. ► The composite was synthesized via a microwave-assisted reflux method. ► The composite with 12.9% graphite oxide showed the maximum specific capacitance. ► The composite electrode exhibited excellent cycling stability. A microwave-assisted reflux method was used to rapidly synthesize CoAl-layered double hydroxide (CoAl-LDH)/graphene oxide composite. In the synthetic procedure, graphite oxide (GO) was exfoliated to graphene oxide nanosheets in company with the in situ growth of CoAl-LDH. The as-prepared products showed lamellar structures. The aggregation of LDH was effectively prevented by the presence of graphene oxide nanosheets. Electrochemical performances were evaluated by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge–discharge tests. All the composites had higher rate capability than pure CoAl-LDH, maintaining about 80% of discharge capacitance when the current density increased from 1Ag−1 to 20Ag−1. A maximum specific capacitance of 772Fg−1 was obtained at 1Ag−1 in 6M KOH solution for the composite containing 12.9% GO. Moreover, the composite exhibited excellent long cycle life with about 73% specific capacitance retained at 6Ag−1 after 10,000 cycles.