Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6608247 | Electrochimica Acta | 2016 | 32 Pages |
Abstract
3D graphene-based frameworks with interpenetrating macroporous structures have attracted great interests recently since they can serve as robust matrix for accommodating guest nanoparticles for use in a wide range of applications. Here, an adsorption-hydrothermal strategy is adopted for the in-situ growth of Ni(OH)2 nanoplates using three dimensional (3D) nitrogen-containing graphene hydrogel (NG) as the substrate. The NG/Ni(OH)2 nanocomposite hydrogel thus obtained is explored as the monolithic free-standing supercapacitor electrode without adding any other binders or conductive additives. The 3D hierarchical structure of the NG/Ni(OH)2 nanocomposite can not only provide a large accessible surface area, but also facilitate ion diffusion and charge transport for much improved supercapacitive performance. The gel with Ni(OH)2 loading of â¼40% achieves a high specific capacitance of 782Â FÂ gâ1Â at the current density of 0.2Â AÂ gâ1, which equals to a specific capacitance of 1748Â FÂ gâ1 based on the mass of Ni(OH)2 alone. Excellent cycling stability of only 10% capacitance loss after 10000 cycles is also achieved due to the robust adhesion between the metal hydroxide and nitrogen containing graphene. Furthermore, high capacitance retention of â¼80% can be achieved when the current density is increased 100 fold from 0.2 to 20Â AÂ gâ1.
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Authors
Lu Mao, Cao Guan, Xiaolei Huang, Qingqing Ke, Yu Zhang, John Wang,