Electrodeposition of porous graphene networks on nickel foams as supercapacitor electrodes with high capacitance and rem
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NANO EXPRESS
Open Access
Electrodeposition of porous graphene networks on nickel foams as supercapacitor electrodes with high capacitance and remarkable cyclic stability Shaolin Yang1, Bingchen Deng2, Ruijing Ge2, Li Zhang1, Hong Wang1, Zihan Zhang1, Wei Zhu1* and Guanzhong Wang1*
Abstract We describe a facile, low-cost, and green method to fabricate porous graphene networks/nickel foam (PG/NF) electrodes by electrochemical deposition of graphene sheets on nickel foams (NFs) for the application of supercapacitor electrodes. The electrodeposition process was accomplished by electrochemical reduction of graphene oxide (GO) in its aqueous suspension. The resultant binder-free PG/NF electrodes exhibited excellent double-layer capacitive performance with a high rate capability and a high specific capacitance of 183.2 mF cm−2 at the current density of 1 mA cm−2. Moreover, the specific capacitance maintains nearly 100% over 10,000 charge-discharge cycles, demonstrating a remarkable cyclic stability of these porous supercapacitor electrodes. Keywords: Graphene; Porous; Electrodeposition; Nickel foam; Crumpled morphology; Supercapacitor; Electrode PACS: 82.47.Uv (Electrochemical capacitors); 82.45.Fk (Electrodes electrochemistry); 81.05.Rm (Fabrication of porous materials)
Background Supercapacitors have attracted tremendous attention due to their novel characteristics, including rapid chargingdischarging rate, high power density, long cycle life, and high dynamic of charge propagation [1-4]. Supercapacitors generally fall into two categories according to the specific energy storage mechanism [5,6]. One type is called electrical double-layer capacitors (EDLCs) which store energy with the pure electrostatic charge adsorbed at the electrode-electrolyte interface. The second type is the pseudocapacitors that store energy through fast and reversible Faradic surface or near-surface redox reactions. Compared with pseudocapacitors, EDLCs usually have higher rate performance, better cycling stability, and longer lifetime [7]. Carbon materials including active carbon, carbon nanotubes, xerogel, mesoporous carbon, and carbide-derived carbon have been developed as electrodes in EDLCs [5,8-13]. * Correspondence: [email protected]; [email protected] 1 Hefei National Laboratory for Physical Sciences at Microscale, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China Full list of author information is available at the end of the article
In the last few years, graphene, a two-dimensional carbon material, has been extensively studied as a candidate for EDLC electrode material owing to its large specific surface area, very high electrical conductivity, and profuse interlayer structure in comparison with traditional porous carbon materials [6,7,14-16]. However, graphene-based electrodes often suffer from stacking and self-aggregation of graphene sheets due to the strong π-π interaction among graphene layers, which will impede the diffusion of electrolyte, decrease the a
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