In this work, a two-step electrodeposition strategy is developed for the synthesis of core-shell Co₃O₄@CoS nanosheet arrays on carbon cloth (CC) for supercapacitor applications. Porous Co₃O₄ nanosheet arrays are first directly grown on CC by electrodeposition, followed by the coating of a thin layer of CoS on the surface of Co₃O₄ nanosheets via the secondary electrodeposition. The morphology control of the ternary composites can be easily achieved by altering the number of cyclic voltammetry (CV) cycles of CoS deposition. Electrochemical performance of the composite electrodes was evaluated by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy techniques. The results demonstrate that the Co₃O₄@CoS/CC with 4 CV cycles of CoS deposition possesses the largest specific capacitance 887.5 F·g-1 at a scan rate of 10 mV·s-1 (764.2 F·g-1 at a current density of 1.0 A·g-1), and excellent cycling stability (78.1% capacitance retention) at high current density of 5.0 A·g-1 after 5000 cycles. The porous nanostructures on CC not only provide large accessible surface area for fast ions diffusion, electron transport and efficient utilization of active CoS and Co₃O₄, but also reduce the internal resistance of electrodes, which leads to superior electrochemical performance of Co₃O₄@CoS/CC composite at 4 cycles of CoS deposition.

Centre of Polymer Systems Tomas Bata University in Zlin nam T G Masaryka 5555 Zlin 760 01 Czech Republic

Key Laboratory for Ultrafine Materials of Ministry of Education School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 China

See more in PubMed

Liu C., Li F., Ma L.-P., Cheng H.M. Advanced materials for energy storage. Adv. Mater. 2010;22:28–62. doi: 10.1002/adma.200903328. PubMed DOI

Wang Y., Xia Y. Recent progress in supercapacitors: From materials design to system construction. Adv. Mater. 2013;25:5336–5342. doi: 10.1002/adma.201301932. PubMed DOI

Hu Q., Gu Z., Zheng X., Zhang X. Three-dimensional Co3O4@NiO hierarchical nanowire arrays for solid-state symmetric supercapacitor with enhanced electrochemical performances. Chem. Eng. J. 2016;304:223–231. doi: 10.1016/j.cej.2016.06.097. DOI

Wang G., Zhang L., Zhang J. A review of electrode materials for electrochemical supercapacitors. Chem. Soc. Rev. 2011;41:797–828. doi: 10.1039/C1CS15060J. PubMed DOI

Shao M., Li Z., Zhang R., Ning F., Wei M., Evans D.G., Duan X. Hierarchical conducting polymer@clay core-shell arrays for flexible all-solid-state supercapacitor devices. Small. 2015;11:3530–3538. doi: 10.1002/smll.201403421. PubMed DOI

Xia X.H., Tu J.P., Mai Y.J., Wang X.L., Gu C.D., Zhao X.B. Self-supported hydrothermal synthesized hollow Co3O4 nanowire arrays with high supercapacitor capacitance. J. Mater. Chem. 2011;21:9319–9325. doi: 10.1039/c1jm10946d. DOI

Meher S.K., Rao G.R. Ultra layered Co3O4 for high-performance supercapacitor applications. J. Phys. Chem. C. 2011;115:15646–15654. doi: 10.1021/jp201200e. DOI

Xia X.H., Tu J.P., Zhang Y.Q., Mai Y.J., Wang X.L., Gu C.D., Zhao X.B. Freestanding Co3O4 nanowire array for high performance supercapacitors. RSC Adv. 2012;2:1835–1841. doi: 10.1039/c1ra00771h. DOI

Silva R., Pereira G.M., Voiry D., Chhowalla M., Asefa T. Co3O4 nanoparticles/cellulose nanowhiskers derived amorphous carbon nanoneedles: Sustainable materials for supercapacitors and oxygen reduction electrocatalysis. RSC Adv. 2015;5:49385–49391. doi: 10.1039/C5RA08037A. DOI

Sun G., Ma L., Ran J., Shen X., Tong H. Incorporation of homogeneous Co3O4 into a nitrogen-doped carbon aerogel: Via a facile in situ synthesis method: Implications for high performance asymmetric supercapacitors. J. Mater. Chem. A. 2016;4:9542–9554. doi: 10.1039/C6TA03884K. DOI

Ke Q., Tang C., Yang Z.C., Zheng M., Mao L., Liu H., Wang J. 3D Nanostructure of carbon nanotubes decorated Co3O4 nanowire arrays for high performance supercapacitor electrode. Electrochim. Acta. 2015;163:9–15. doi: 10.1016/j.electacta.2015.02.136. DOI

Raj R.P., Ragupathy P., Mohan S. Remarkable capacitive behavior of a Co3O4-polyindole composite as electrode material for supercapacitor applications. J. Mater. Chem. A. 2015;3:24338–24348. doi: 10.1039/C5TA07046E. DOI

Lin H., Huang Q., Wang J., Jiang J., Liu F., Chen Y., Wang C., Lu D., Han S. self-assembled graphene/polyaniline/Co3O4 ternary hybrid aerogels for supercapacitors. Electrochim. Acta. 2016;191:444–451. doi: 10.1016/j.electacta.2015.12.143. DOI

Hong W., Wang J., Li Z., Yang S. Hierarchical Co3O4@Au-decorated PPy core/shell nanowire arrays: An efficient integration of active materials for energy storage. J. Mater. Chem. A. 2015;3:2535–2540. doi: 10.1039/C4TA04707A. DOI

Kong D., Luo J., Wang Y., Ren W., Yu T., Luo Y., Yang Y., Cheng C. Three-dimensional Co3O4@MnO2 hierarchical nanoneedle arrays: Morphology control and electrochemical energy etorage. Adv. Funct. Mater. 2014;24:3815–3826. doi: 10.1002/adfm.201304206. DOI

Tang C.H., Yin X., Gong H. Superior performance asymmetric supercapacitors based on a directly grown commercial mass 3D Co3O4@Ni(OH)2 core-shell electrode. ACS Appl. Mater. Interfaces. 2013;5:10574–10582. doi: 10.1021/am402436q. PubMed DOI

Zhong J.H., Wang A.L., Li G.R., Wang J.W., Ou Y.N., Tong Y.X. Co3O4/Ni(OH)2 composite mesoporous nanosheet networks as a promising electrode for supercapacitor applications. J. Mater. Chem. 2012;22:5656–5665. doi: 10.1039/c2jm15863a. DOI

Zhang G., Wang T., Yu X., Zhang H., Duan H., Lu B. Nanoforest of hierarchical Co3O4@NiCo2O4 nanowire arrays for high-performance supercapacitors. Nano Energy. 2013;2:586–594. doi: 10.1016/j.nanoen.2013.07.008. DOI

Li S., Wen J., Chen T., Xiong L., Wang J., Fang G. In situ synthesis of 3D CoS nanoflake/Ni(OH)2 nanosheet nanocomposite structure as a candidate supercapacitor electrode. Nanotechnology. 2016;27:1–9. PubMed

Luo F., Li J., Yuan H., Xiao D. Rapid synthesis of three-dimensional flower-like cobalt sulfide hierarchitectures by microwave assisted heating method for high-performance supercapacitors. Electrochim. Acta. 2014;123:183–189. doi: 10.1016/j.electacta.2014.01.009. DOI

Ray R.S., Sarma B., Jurovitzki A.L., Misra M. Fabrication and characterization of titania nanotube/cobalt sulfide supercapacitor electrode in various electrolytes. Chem. Eng. J. 2015;260:671–683. doi: 10.1016/j.cej.2014.07.031. DOI

Wang A., Wang H., Zhang S., Mao C., Song J., Niu H., Jin B., Tian Y. Controlled synthesis of nickel sulfide/graphene oxide nanocomposite for high-performance supercapacitor. Appl. Surf. Sci. 2013;282:704–708. doi: 10.1016/j.apsusc.2013.06.038. DOI

Wu J., Ouyang C., Dou S., Wang S. Hybrid NiS/CoO mesoporous nanosheet arrays on Ni foam for high-rate supercapacitors. Nanotechnology. 2015;26:1–8. doi: 10.1088/0957-4484/26/32/325401. PubMed DOI

Javed M.S., Dai S., Wang M., Guo D., Chen L., Wang X., Hu C., Xi Y. High performance solid state flexible supercapacitor based on molybdenum sulfide hierarchical nanospheres. J. Power Sourous. 2015;285:63–69. doi: 10.1016/j.jpowsour.2015.03.079. DOI

Yu X.Y., Yu L., Shen L., Song X., Chen H., Lou X.W. General formation of MS (M = Ni, Cu, Mn) box-in-box hollow structures with enhanced pseudocapacitive properties. Adv. Funct. Mater. 2014;24:7440–7446. doi: 10.1002/adfm.201402560. DOI

Wang H.Y., Xiao F.X., Yu L., Liu B., Lou X.W. Hierarchical α-MnO2 nanowires@Ni1−xMnxOy nanoflakes core-shell nanostructures for supercapacitors. Small. 2014;10:3181–3186. doi: 10.1002/smll.201303836. PubMed DOI

Wang X., Lu X., Liu B., Chen D., Tong Y., Shen G. Flexible energy-storage devices: Design consideration and recent progress. Adv. Mater. 2014;26:4763–4782. doi: 10.1002/adma.201400910. PubMed DOI

Xu J., Wang K., Zu S.Z., Han B.H., Wei Z. Hierarchical nanocomposites of polyaniline nanowire arrays on graphene oxide sheets with synergistic effect for energy storage. ACS Nano. 2010;4:5019–5026. doi: 10.1021/nn1006539. PubMed DOI

Liu B., Kong D., Zhang J., Wang Y., Chen T., Cheng C., Yang H.Y. 3D hierarchical Co3O4@Co3S4 nanoarrays as cathode materials for asymmetric pseudocapacitors. J. Mater. Chem. A. 2016;4:3287–3296. doi: 10.1039/C5TA09344A. DOI

Zhang L., Huang T.J., Gong H. Remarkable improvement in supercapacitor performance by sulfur introduction during a one-step synthesis of nickel hydroxide. Phys. Chem. Chem. Phys. 2017;19:10462–10469. doi: 10.1039/C7CP01234A. PubMed DOI

Yang L., Cheng S., Ding Y., Zhu X., Wang Z.L., Liu M. Hierarchical network architectures of carbon fiber paper supported cobalt oxide nanonet for high-capacity pseudocapacitors. Nano Lett. 2012;12:321–325. doi: 10.1021/nl203600x. PubMed DOI

Li R., Wang S., Wang J., Huang Z. N3S2@CoS core-shell nano-triangular pyramid arrays on Ni foam for high-performance supercapacitors. Phys. Chem. Chem. Phys. 2015;17:16434–16442. doi: 10.1039/C5CP01945A. PubMed DOI

Li X., Guan G., Du X., Jagadale A.D., Cao J., Hao X., Ma X., Abudula A. Homogeneous nanosheet Co3O4 film prepared by novel unipolar pulse electro-deposition method for electrochemical water splitting. RSC Adv. 2015;5:76026–76031. doi: 10.1039/C5RA12822F. DOI

Li H., He Y., Pavlinek V., Cheng Q., Saha P., Li C. MnO2 nanoflake/polyaniline nanorod hybrid nanostructures on graphene paper for high-performance flexible supercapacitor electrodes. J. Mater. Chem. A. 2015;3:17165–17171. doi: 10.1039/C5TA04008F. DOI

Kim C., Yang K., Kojima M., Yoshida K., Kim Y.J., Kim Y.A., Endo M. Fabrication of electrospinning-derived carbon nanofiber webs for the anode material of lithium-ion secondary batteries. Adv. Funct. Mater. 2006;16:2393–2397. doi: 10.1002/adfm.200500911. DOI

Dong X.C., Xu H., Wang X.W., Huang Y.X., Chan-Park M.B., Zhang H., Wang L.H., Huang W., Chen P. 3D graphene–cobalt oxide electrode for high-performance supercapacitor and enzymeless glucose detection. ACS Nano. 2012;6:3206–3213. doi: 10.1021/nn300097q. PubMed DOI

Hadjiev V.G., Iliev M.N., Vergilov I.V. The Raman spectra of Co3O4. J. Phys. C Solid State Phys. 1988;21:199–201. doi: 10.1088/0022-3719/21/7/007. DOI

Xu J., Fu G., Tang Y., Zhao T.S. Non-precious Co3O4 nano-rod electrocatalyst for oxygen reduction reaction in anion-exchange membrane fuel cells. Energy Environ. Sci. 2012;5:5333–5339. doi: 10.1039/C1EE01431E. DOI

Sun H., Qin D., Huang S., Guo X., Li D., Luo Y., Meng Q. Dye-sensitized solar cells with NiS counter electrodes electrodeposited by a potential reversal technique. Energy Environ. Sci. 2011;4:2630–2637. doi: 10.1039/c0ee00791a. DOI

Mate V.R., Shirai M., Rode C.V. Heterogeneous Co3O4, catalyst for selective oxidation of aqueous veratryl alcohol using molecular oxygen. Catal. Commun. 2013;33:66–69. doi: 10.1016/j.catcom.2012.12.015. DOI

Tao F., Zhao Y.Q., Zhang G.Q., Li H.L. Electrochemical characterization on cobalt sulfide for electrochemical supercapacitors. Electrochem. Commun. 2007;9:1282–1287. doi: 10.1016/j.elecom.2006.11.022. DOI

Chen C.Y., Shih Z.Y., Yang Z., Chang H.T. Carbon nanotubes/cobalt sulfide composites as potential high-rate and high-efficiency supercapacitors. J. Power Sourous. 2012;215:43–47. doi: 10.1016/j.jpowsour.2012.04.075. DOI

Huang C.W., Teng H. Influence of carbon nanotube grafting on the impedance behavior of activated carbon capacitors. J. Electrochem. Soc. 2008;155:739–744. doi: 10.1149/1.2965503. DOI

Li W., Li G., Sun J., Zou R., Xu K., Sun Y., Chen Z., Yang J., Hu J. Hierarchical heterostructures of MnO2 nanosheets or nanorods grown on Au-coated Co3O4 porous nanowalls for high-performance pseudocapacitance. Nanoscale. 2013;5:2901–2908. doi: 10.1039/c3nr34140b. PubMed DOI

Hierarchical PANI/NiCo-LDH Core-Shell Composite Networks on Carbon Cloth for High Performance Asymmetric Supercapacitor