Electrodeposition of manganese oxide nanosheets on a continuous three-dimensional nickel porous scaffold for high performance electrochemical capacitors

It's desirable to design an ideal three-dimensional (3D) interpenetrating network as the current collector for providing efficient ion and electron transport. Herein, we report a facile method to fabricate a novel continuous 3D Ni porous nanoarchitecture via the reduction of Ni(OH)(2) nanowall precursors. The as-formed continuous 3D Ni porous network as the conductive scaffold can support a highly electrolytic accessible surface area of redox active MnO2 nanosheets, and provide reliable electrical connections to the MnO2 layers. In comparison with the planar conducting substrates, this 3D scaffold not only can increase the mass loading of MnO2 active materials, but also facilitate the facile transport of electron and electrolyte ion. Thus, the 3D (MnO2/Ni) electrode exhibited higher specific capacitance (1169.6 F g(-1) at 2 A g, closed to the theoretical value) and better long-term cyclability (only similar to 5% loss after 1000 cycles) than that on the planar conducting substrate under the identical electrodeposition condition (611.6 F g(-1) at 2 A g(-1) and around 20% loss after 1000 cycles). These results suggest that such 3D Ni porous architecture is a promising current collector for high-performance electrochemical capacitor. (C) 2013 Elsevier B.V. All rights reserved.