Freestanding Needle Flower Structure CuCo2S4 on Carbon Cloth for Flexible High Energy Supercapacitors With the Gel Electrolyte

Abstract

A facile hydrothermal approach was adopted to the direct synthesis of bimetallic sulfide (CuCo 2 S 4 ) on carbon cloth (CC) without binders for the supercapacitor's electrodes. A possible formation mechanism was proposed. The prepared bimetallic electrode exhibited a high specific capacitance (Csp) of 1,312 F·g −1 at 1 A·g −1 , and an excellent capacitance retention of 94% at 5 A·g −1 over 5,000 cycles. In addition, the asymmetric supercapacitor (CuCo 2 S 4 /CC//AC/CC) exhibited energy density (42.9 wh·kg −1 at 0.8 kW·kg −1 ) and outstanding cycle performance (80% initial capacity retention after 5,000 cycles at 10 A·g −1 ). It should be noted that the electrochemical performance of a supercapacitor device is quite stable at different bending angles. Two charged devices in series can light 28 red-colored LEDs (2.0 V) for 5 min. All of this serves to indicate the potentially high application value of CuCo 2 S 4 .

A Reduced ‐ Graphene ‐ Oxide Entrapped CuCo2S4 Nano‐Array for High‐performance Supercapacitor Electrode

“…At high scan rate, the OH − ions can access only the outer active sites of the electrode due to short interval and because of the low utilization of active materials shifting in peaks occurs. The possible mechanism of interaction of OH − may be as follows in equation (1–3) [18] ‐ $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr Cu{Co}_{2}{S}_{4}{\rm \ }+2O{H}^{-}{\rm \ }{\rm \ }\leftrightarrow \hfill\cr Cu{Co}_{2}{S}_{4}(O{H}^{-}{)}_{2}+2{\rm \ }{e}^{-1}{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }\hfill\cr}}$$$ $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr CoSOH+{\rm \ }O{H}^{-}{\rm \ }\leftrightarrow CoSO+{\rm \ }{H}_{2}O+{\rm \ }{e}^{-1}{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }{\rm \ }\hfill\cr}}$$$ …”

In Situ Growth of Core–Shell Heterostructure CePO4@CuCo2S4 As Advanced Electrodes for High-Performance Supercapacitor

“…The possible redox reactions responsible for CePO 4 @CuCo 2 S 4 /NF are as follows (eqs –): ,, The GCD curves of CeO 2 /NF, CePO 4 /NF, and CuCo 2 S 4 /NF electrodes at different densities are exhibited (Figure S6a–c). In order to further highlight the advantages of CePO 4 @CuCo 2 S 4 active material and reduce the water decomposition reaction during the low current density measurement, 6 M KOH electrolyte is used for testing, thus the voltage window of GCD measured in CePO 4 @CuCo 2 S 4 electrode materials is the most appropriate voltage window at 0∼0.3 V. All GCD curves of CeO 2 /NF, CePO 4 /NF, and CuCo 2 S 4 /NF electrodes reveal approximately symmetrical charge–discharge times at different current densities, which means that they have good reversibility of charging and discharging process.…”

Fabrication of Nanocluster-Aggregated Dense Ce2(MoO4)3 Microspherical Architectures for High-Voltage Energy Storage and High Catalytic Energy Conversion Applications

“…Zhu and Zheng developed Co 3 O 4 anchored on g-C 3 N 4 by the chemical precipitation route and obtained excellent performance including a specific capacitance of 780 F g –1 at 1.25 A g –1 with a retention of 80% after 1000 cycles in 2 M KOH . Xie et al fabricated an asymmetric supercapacitor based on the CuCo 2 S 4 /CC needle flower structure and reported an energy density of 42.9 W h kg –1 at 0.8 kW kg –1 with a specific capacitance retention of 80% after 5000 GCD cycles . Shao et al reported the binder-free Co 3 (PO 4 ) 2 ·8H 2 O electrode material, prepared by the hydrothermal route for the supercapacitor application.…”

“…37 Xie et al fabricated an asymmetric supercapacitor based on the CuCo 2 S 4 /CC needle flower structure and reported an energy density of 42.9 W h kg −1 at 0.8 kW kg −1 with a specific capacitance retention of 80% after 5000 GCD cycles. 38 Shao et al reported the binder-free Co 3 (PO 4 ) 2 •8H 2 O electrode material, prepared by the hydrothermal route for the supercapacitor application. They had obtained a specific capacitance of 111.2 F g −1 with a specific energy of 29.29 W h kg −1 at a specific power of 4687 W kg −1 using the supercapacitor device.…”