title: Three-dimensional metal/oxide nanocone arrays for high-performance electrochemical pseudocapacitors.
abstract: Three-dimensional (3D) electrodes are critical for enabling high-performance power sources. We report here on the design and fabrication, by combining imprint and soft-printing technologies, of 3D nanocone arrays as a novel platform for high performance pseudocapacitors. Such purpose-built 3D nanocone arrays have the advantages of simplicity/versatility/reliability of fabrication, generality to a vast range of active materials, high electrode surface area, and ease of electrolyte permeation. As a demonstration of principle, Au and MnO2 were sequentially deposited forming a 3D Au/MnOx nanocone array electrode for a pseudocapacitor device. This device achieved a specific mass (areal) capacitance of 840.3 F g(-1) (88.2 mF cm(-2)) at a current density of 2 A g(-1). Additionally, the asymmetric supercapacitor using the Au/MnOx nanocone array as the positive electrode and a carbon-based material as the negative electrode achieved a capacitance of 108.5 F g(-1) at a current density of 1 A g(-1), corresponding to an energy density of as high as 46.8 W h kg(-1) at a power density of 0.72 kW kg(-1). The cell still preserved 96.5% of the initial capacitance even after 2000 cycles at a current density of 2 A g(-1). The initial result is at least on a par with those of the best asymmetric supercapacitors reported so far, and thus bolsters the development value of the conductive nanocone arrays for high-performance supercapacitors and other energy-storage devices.
authors.affiliation: Nano Science and Technology Program, Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China. ygzhang2012@sinano.ac.cn eezfan@ust.hk chsyang@ust.hk.
authors.forename: Yongcai
authors.initials: Y
authors.lastname: Qiu
authors.forename: Yihua
authors.initials: Y
authors.lastname: Zhao
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Yang
authors.forename: Wanfei
authors.initials: W
authors.lastname: Li
authors.forename: Zhanhua
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authors.lastname: Wei
authors.forename: Junwu
authors.initials: J
authors.lastname: Xiao
authors.forename: Siu-Fung
authors.initials: SF
authors.lastname: Leung
authors.forename: Qingfeng
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authors.lastname: Lin
authors.forename: Hongkai
authors.initials: H
authors.lastname: Wu
authors.forename: Yuegang
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authors.lastname: Zhang
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Fan
authors.forename: Shihe
authors.initials: S
authors.lastname: Yang