title: Self-Stacked Reduced Graphene Oxide Nanosheets Coated with Cobalt-Nickel Hydroxide by One-Step Electrochemical Deposition toward Flexible Electrochromic Supercapacitors.
abstract: The implementation of an optical function into supercapacitors is an innovative approach to make energy storage devices smarter and to meet the requirements of smart electronics. Here, it is reported for the first time that nickel-cobalt hydroxide on reduced graphene oxide can be utilized for flexible electrochromic supercapacitors. A new and straightforward one-step electrochemical deposition process is introduced that is capable of simultaneously reducing GO and depositing amorphous Co(1-x)Ni(x)(OH)2 on the rGO. It is shown that the rGO nanosheets are homogeneously coated with metal hydroxide and are vertically stacked. No high temperature processes are used so that flexible polymer-based substrates can be coated. The synthesized self-stacked rGO-Co(1-x)Ni(x)(OH)2 nanosheet material exhibits pseudocapacitive charge storage behavior with excellent rate capability, high Columbic efficiency, and nondiffusion limited behavior. It is shown that the electrochemical behavior of the Ni(OH)2 can be modulated, by simultaneously depositing nickel and cobalt hydroxide, into broad oxidization and reduction bands. Further, the material exhibits electrochromic property and can switch between a bleached and transparent state. Literature comparison reveals that the performance characteristics of the rGO-Co(1-x)Ni(x)(OH)2 nanosheet material, in terms of gravimetric capacitance, areal capacitance, and long-term cycling stability, are among the highest reported values of supercapacitors with electrochromic property.
authors.affiliation: Ilmenau University of Technology, Institute of Physics and IMN MacroNano®(ZIK), Prof. Schmidt Str. 26, 98693, Ilmenau, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Grote
authors.affiliation: Division of Nanomaterials and Chemistry, Hefei National Laboratory for Physical Sciences at Microscale, Collaborative Innovation Center of Suzhou Nano, Science and Technology, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
authors.forename: Zi-You
authors.initials: ZY
authors.lastname: Yu
authors.affiliation: Division of Nanomaterials and Chemistry, Hefei National Laboratory for Physical Sciences at Microscale, Collaborative Innovation Center of Suzhou Nano, Science and Technology, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
authors.forename: Jin-Long
authors.initials: JL
authors.lastname: Wang
authors.affiliation: Division of Nanomaterials and Chemistry, Hefei National Laboratory for Physical Sciences at Microscale, Collaborative Innovation Center of Suzhou Nano, Science and Technology, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
authors.forename: Shu-Hong
authors.initials: SH
authors.lastname: Yu
authors.affiliation: Ilmenau University of Technology, Institute of Physics and IMN MacroNano®(ZIK), Prof. Schmidt Str. 26, 98693, Ilmenau, Germany.
authors.forename: Yong
authors.initials: Y
authors.lastname: Lei
keywords: electrochromics; metal hydroxides; nanosheets; reduced graphene oxides; supercapacitors