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. 2018 Aug 18;11(8):1468.
doi: 10.3390/ma11081468.

Hydrothermal Synthesis of Co-Doped NiSe₂ Nanowire for High-Performance Asymmetric Supercapacitors

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Free PMC article

Hydrothermal Synthesis of Co-Doped NiSe₂ Nanowire for High-Performance Asymmetric Supercapacitors

Yun Gu et al. Materials (Basel). .
Free PMC article

Abstract

Co@NiSe₂ electrode materials were synthesized via a simple hydrothermal method by using nickel foam in situ as the backbone and subsequently characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and a specific surface area analyzer. Results show that the Co@NiSe₂ electrode exhibits a nanowire structure and grows uniformly on the nickel foam base. These features make the electrode show a relatively high specific surface area and electrical conductivity, and thus exhibit excellent electrochemical performance. The obtained electrode has a high specific capacitance of 3167.6 F·g-1 at a current density of 1 A·g-1. To enlarge the potential window and increase the energy density, an asymmetric supercapacitor was assembled by using a Co@NiSe₂ electrode and activated carbon acting as positive and negative electrodes, respectively. The prepared asymmetrical supercapacitor functions stably under the potential window of 0⁻1.6 V. The asymmetric supercapacitor can deliver a high energy density of 50.0 Wh·kg-1 at a power density of 779.0 W·kg-1. Moreover, the prepared asymmetric supercapacitor exhibits a good rate performance and cycle stability.

Keywords: Co-doped NiSe2; asymmetric supercapacitors; hydrothermal method; nanowire; pseudocapacitance.

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
(a) X-ray diffraction (XRD) patterns of blank nickel foam (NF), NiSe2, and Co@NiSe2-2; (b) energy-dispersive X-ray spectroscopy (EDS) spectrum of Co@NiSe2-2.
Figure 2
Figure 2
Field emission scanning electron microscopy (FESEM) images of (a,b) NiSe2; (c,d) Co@NiSe2-1; (e,f) Co@NiSe2-2; (g,h) Co@NiSe2-3; (i,j) transmission electron microscopy (TEM) images of Co@NiSe2-2 electrode materials.
Figure 2
Figure 2
Field emission scanning electron microscopy (FESEM) images of (a,b) NiSe2; (c,d) Co@NiSe2-1; (e,f) Co@NiSe2-2; (g,h) Co@NiSe2-3; (i,j) transmission electron microscopy (TEM) images of Co@NiSe2-2 electrode materials.
Figure 3
Figure 3
N2 absorption–desorption curves and pore size distributions of (a) NiSe2; (b) Co@NiSe2-1; (c) Co@NiSe2-2; and (d) Co@NiSe2-3 electrode materials.
Figure 4
Figure 4
(a) Cyclic voltammetry (CV) curves of electrode materials at a scan rate of 5 mV·s−1; (b) galvanostatic charge-discharge (GCD) curves of electrode materials at a current density of 1 A·g−1; (c) Nyquist plots of electrode materials (the inset is the enlarged curves at a high-frequency curve range); (d) equivalent circuit used to fit the Nyquist spectra.
Figure 5
Figure 5
(a) CV curves of Co@NiSe2-2 electrode at different scan rates; (b) relationship of the square root of the scan rate and the peak current; (c) GCD curves of Co@NiSe2-2 electrode at different current densities; (d) specific capacitance of Co@NiSe2-2 electrode at different current densities.
Figure 6
Figure 6
CV curves of the activated carbon (AC) electrode and the Co@NiSe2-2 electrode in a three-electrode system.
Figure 7
Figure 7
(a) CV curves of Co@NiSe2-2//AC asymmetric supercapacitor at a scan rate of 50 mV·s−1 at different potential windows; (b) GCD curves of Co@NiSe2-2//AC asymmetric supercapacitor at different potential windows at a current density of 1 A·g−1; (c) plots of specific capacitances for NiSe2//AC and Co@NiSe2-2//AC asymmetric supercapacitors at different potential windows; (d) CV curves of Co@NiSe2-2//AC at different scanning rates; (e) GCD curves of Co@NiSe2-2//AC asymmetric supercapacitor at different current densities; (f) plots of specific capacitances for NiSe2//AC, Co@NiSe2-2//AC asymmetric supercapacitors at different current densities.
Figure 8
Figure 8
(a) Ragone polts; (b) cyclic performances tested at a current density of 1 A·g−1 of NiSe2//AC and Co@NiSe2-2//AC asymmetric supercapacitors.

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References

    1. Bruce P.G., Freunberger S.A., Hardwick L.J., Tarascon J.M. Li-O2 and Li-S batteries with high energy storage. Nat. Mater. 2011;11:19–29. doi: 10.1038/nmat3191. - DOI - PubMed
    1. Li Q., Zheng S., Xu Y., Xue H., Pang H. Ruthenium based materials as electrode materials for supercapacitors. Chem. Eng. J. 2017;333:505–518. doi: 10.1016/j.cej.2017.09.170. - DOI
    1. Salanne M., Rotenberg B., Naoi K., Kaneko K., Taberna P.L., Grey C.P., Dunn B., Simon P. Efficient storage mechanisms for building better supercapacitors. Nat. Energy. 2016;1:16070. doi: 10.1038/nenergy.2016.70. - DOI
    1. Daraghmeh A., Hussain S., Servera L., Xuriguera E., Cornet A., Cirera A. Impact of binder concentration and pressure on performance of symmetric CNFs based supercapacitors. Electrochim. Acta. 2017;245:531–538. doi: 10.1016/j.electacta.2017.05.186. - DOI
    1. Zhang L., Hu X., Wang Z., Sun F., Dorrell D.G. A review of supercapacitor modeling, estimation, and applications: A control/management perspective. Renew. Sustain. Energy Rev. 2017;81:1868–1878. doi: 10.1016/j.rser.2017.05.283. - DOI
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