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Cobalt Doping To Boost the Electrochemical Properties of Ni@Ni 3 S 2 Nanowire Films for High‐Performance Supercapacitors
Author(s) -
Xu Shusheng,
Wang Tao,
Ma Yujie,
Jiang Wenkai,
Wang Shuai,
Hong Min,
Hu Nantao,
Su Yanjie,
Zhang Yafei,
Yang Zhi
Publication year - 2017
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201701305
Subject(s) - materials science , supercapacitor , electrode , nanowire , electrochemistry , capacitance , cobalt , graphene , doping , nanotechnology , energy storage , chemical engineering , fabrication , cobalt oxide , optoelectronics , metallurgy , chemistry , power (physics) , physics , alternative medicine , quantum mechanics , pathology , engineering , medicine
Metal sulfides have aroused great interest for energy storage. However, their low specific capacities and inferior rate capabilities hinder their practical applications. In this work, a facile cobalt‐doping process is used to boost the electrochemical performance of Ni@Ni 3 S 2 core–sheath nanowire film electrodes for high‐performance electrochemical energy storage. Co ions are doped successfully and uniformly into Ni 3 S 2 nanosheets through a facile ion‐exchange process. The electrochemical properties of film electrodes are improved greatly, and an ultrahigh volumetric capacity (increased from 105 to 730 C cm −3 at 0.25 A cm −3 ) and excellent rate capability are obtained after Co is doped into Ni@Ni 3 S 2 core–sheath nanowires. A hybrid asymmetric supercapacitor with Co‐doped Ni@Ni 3 S 2 as the positive electrode and graphene‐carbon nanotubes as the negative electrode is assembled and exhibits an ultrahigh volumetric capacitance of 142 F cm −3 (based on the total volume of both electrodes) at 0.5 A cm −3 and excellent cycling stability (only 3 % capacitance decrease after 5000 cycles). Moreover, the volumetric energy density can reach 44.5 mWh cm −3 , which is much larger than those of thin‐film lithium batteries (1–10 mWh cm −3 ). These results may provide useful insights for the fabrication of high ‐ performance film electrodes for energy‐storage applications.