Indexed by:
期刊论文
First Author:
Li, Xiangcun
Correspondence Author:
Li, XC; He, GH (reprint author), Dalian Univ Technol, State Key Lab Fine Chem, 2 Linggong Rd, Dalian 116024, Peoples R China.
Co-author:
Wang, Le,Shi, Jianhang,Du, Naixu,He, Gaohong
Date of Publication:
2016-07-13
Journal:
ACS APPLIED MATERIALS & INTERFACES
Included Journals:
SCIE、EI、PubMed、Scopus
Document Type:
J
Volume:
8
Issue:
27
Page Number:
17276-17283
ISSN No.:
1944-8244
Key Words:
Ni-Co oxides; multishell; hollow microspheres; shell porosity;
pesudocapacitor
Abstract:
Nickel-cobalt oxides/hydroxides have been considered as promising electrode materials for a high-performance supercapacitor. However, their energy density and cycle stability are still very poor at high current density. Moreover, there are few reports on the fabrication of mixed transition-metal oxides with multishelled hollow structures. Here, we demonstrate a new and flexible strategy for the preparation of hollow Ni-Co-O microspheres with optimized Ni/Co ratios, controlled shell porosity, shell numbers, and shell thickness. Owing to its high effective electrode area and electron transfer number (n(3/2) A), mesoporous shells, and fast electron/ion transfer, the triple-shelled Ni-Co-1.5-O electrode exhibits an ultrahigh capacitance (1884 F/g at 3A/g) and rate capability (77.7%, 3-30A/g). Moreover, the assembled sandwiched Ni-Co-1.5-O//RGO@Fe3O4 asymmetric supercapacitor (ACS) retains 79.4% of its initial capacitance after 10 000 cycles and shows a high energy density of 41.5 W h kg(-1) at 505 W kg(-1). Importantly, the ACS device delivers a high energy density of 22.8 W h kg(-1) even at 7600 W kg(-1), which is superior to most of the reported asymmetric capacitors. This study has provided a facile and general approach to fabricate Ni/Co mixed transition-metal oxides for energy storage.
Translation or Not:
no
