title: Self-sacrifice Template Formation of Hollow Hetero-Ni7S6/Co3S4 Nanoboxes with Intriguing Pseudo-capacitance for High-performance Electrochemical Capacitors.
abstract: Herein, we report a simple yet efficient self-sacrifice template protocol to smartly fabricate hollow hetero-Ni7S6/Co3S4 nanoboxes (Ni-Co-S NBs). Uniform nickel cobalt carbonate nanocubes are first synthesized as the precursor via solvothermal strategy, and subsequently chemically sulfidized into hollow heter-Ni-Co-S NBs through anion-exchange process. When evaluated as electrode for electrochemical capacitors (ECs), the resultant hetero-Ni-Co-S NBs visually exhibit attractive pesudo-capacitance in KOH just after continuously cyclic voltammetry (CV) scanning for 100 cycles. New insights into the underlying energy-storage mechanism of the hollow hetero-Ni-Co-S electrode, based on physicochemical characterizations and electrochemical evaluation, are first put forward that the electrochemically induced phase transformation gradually occurrs during CV sweep from the hetero-Ni-Co-S to bi-component-active NiOOH and CoOOH, which are the intrinsic charge-storage phases for the appealing Faradaic capacitance (~677 F g(-1) at 4 A g(-1)) of hollow Ni-Co-S NBs at high rates after cycling. When further coupled with negative activated carbon (AC), the AC//hetero-Ni-Co-S asymmetric device with extended electrochemical window of 1.5 V demonstrates high specific energy density of ~31 Wh kg(-1). Of significance, we strongly envision that hollow design concept and new findings here hold great promise for enriching synthetic methodologies, and electrochemistry of complex metal sulfides for next-generation ECs.
authors: School of Materials Science &Engineering, Anhui University of Technology, Maanshan, 243002, P.R. China.
authors: Hui
authors: H
authors: Hua
authors: School of Materials Science &Engineering, Anhui University of Technology, Maanshan, 243002, P.R. China.
authors: Sijia
authors: S
authors: Liu
authors: School of Materials Science &Engineering, Anhui University of Technology, Maanshan, 243002, P.R. China.
authors: Zhiyi
authors: Z
authors: Chen
authors: School of Materials Science &Engineering, Anhui University of Technology, Maanshan, 243002, P.R. China.
authors: Ruiqi
authors: R
authors: Bao
authors: School of Materials Science &Engineering, Anhui University of Technology, Maanshan, 243002, P.R. China.
authors: Yaoyao
authors: Y
authors: Shi
authors: School of Materials Science &Engineering, Anhui University of Technology, Maanshan, 243002, P.R. China.
authors: Linrui
authors: L
authors: Hou
authors: School of Materials Science &Engineering, Anhui University of Technology, Maanshan, 243002, P.R. China.
authors: Gang
authors: G
authors: Pang
authors: Institute of Applied Physics and Materials Engineering, Faculty of Science and Technology, University of Macau, Macau, P.R. China.
authors: Kwun Nam
authors: KN
authors: Hui
authors: College of Material Science &Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, P.R. China.
authors: Xiaogang
authors: X
authors: Zhang
authors: School of Materials Science &Engineering, Anhui University of Technology, Maanshan, 243002, P.R. China.
authors: Changzhou
authors: C
authors: Yuan