Faradic redox active material of Cu₇S₄ nanowires with a high conductance for flexible solid state supercapacitors

Abstract

The exploration of high Faradic redox active materials with the advantages of low cost and low toxicity has been attracting great attention for producing high energy storage supercapacitors. Here, the high Faradic redox active material of Cu7S4-NWs coated on a carbon fiber fabric (CFF) is directly used as a binder-free electrode for a high performance flexible solid state supercapacitor. The Cu7S4-NW-CFF supercapacitor exhibits excellent electrochemical performance such as a high specific capacitance of 400 F g(-1) at the scan rate of 10 mV s(-1) and a high energy density of 35 Wh kg(-1) at a power density of 200 W kg(-1), with the advantages of a light weight, high flexibility and long term cycling stability by retaining 95% after 5000 charge-discharge cycles at a constant current of 10 mA. The high Faradic redox activity and high conductance behavior of the Cu7S4-NWs result in a high pseudocapacitive performance with a relatively high specific energy and specific power. Such a new type of pseudocapacitive material of Cu7S4-NWs with its low cost is very promising for actual application in supercapacitors.

Room-temperature synthesized porous Cu(OH)2/Cu7S4 hybrid nanowires as a high-performance electrode material for asymmetric supercapacitors

“…The specific capacity, pore volume and specific surface area of the Cu(OH)2/Cu7S4 nanowires were compared with those of copper-based materials reported in literature, and the results are listed in the Table S2. It can be seen that larger pore volumes and larger specific surface areas can lead to large specific capacity 29,32,34,59 . Compared to the other reported copper-based materials, the Cu(OH)2/Cu7S4…”

“…Among these, copper-based nanomaterials have received considerable attention as high-performance electrode materials for hybrid supercapacitors, and these include CuO 25,26 , Cu2O 27,28 , Cu(OH)2 29,30 , CuS 24,31,32 , Cu9S5 33 and Cu7S4 33,34 . They generally have good electrochemical activity, large theoretical capacity and environmental compatibility 35 .…”

“…8a shows the GCD curves of Cu(OH)2/Cu7S4 electrode obtained at different current densities. For all GCDcurves, there are clear voltage plateau in the charge-discharge process, which is resulted from the faradic reactions34 . This further proves the battery-type characteristic of Cu(OH)2/Cu7S4 hybrid nanowires.…”

One-pot synthesis of nickel-cobalt hydroxyfluorides nanowires with ultrahigh energy density for an asymmetric supercapacitor

“…4g, which consisting of semicircles in the high frequency range and a straight line with an angle at almost 45°with the real axis in the low frequency range. It is accepted that the diameter of the semicircle refers to the charge transfer resistance (R ct ), which corresponding to the faradic redox reactions, and the intercept on real axis stands for series resistance (R s ) of the electrochemical system, which is composed by the internal resistance of active materials, ionic resistance, and the interface resistance between electrode and electrolyte interface [35,36]. In order to obtain accurate information of the electrodes, an equivalent circuit was used to fit the Nyquist plots, as shown in inset of Fig.…”

Effect of Graphene Oxide Thin Film on Growth and Electrochemical Performance of Hierarchical Zinc Sulfide Nanoweb for Supercapacitor Applications

“…However, due to various limitations in the materials, practical applications are restricted. For example, carbonaceous electrodes are suited only for EDLCs with low specific capacitance, oxides and MOFs (expensive and difficult fabrication) exhibit poor electrical conductivity ,. Although metal sulfides show fairly well electrical conductivity but the electrochemical performance can be further enhanced by realizing higher electrical conductivity and specific surface area values.…”