Staff directory Xiang Zhang

Publications

2017

• A universal strategy for metal oxide anchored and binder-free carbon matrix electrode: A supercapacitor case with superior rate performance and high mass loading

  Zhang X., Luo J., Tang P., Ye X., Peng X., Tang H., Sun S.-G., Fransaer J. Nano Energy; 31: 311 - 321. 2017. 10.1016/j.nanoen.2016.11.024. IF: 12.343

  Despite the significant advances in preparing carbon-metal oxide composite electrodes, strategies for seamless interconnecting of these two materials without using binders are still scarce. Herein we design a novel method for in situ synthesis of porous 2D-layered carbon–metal oxide composite electrode. Firstly, 2D-layered Ni-Co mixed metal-organic frameworks (MOFs) are deposited directly on nickel foam by anodic electrodeposition. Subsequent pyrolysis and activation procedure lead to the formation of carbon–metal oxides composite electrodes. Even with an ultrahigh mass loading of 13.4 mg cm−2, the as-prepared electrodes exhibit a superior rate performance of 93% (from 1 to 20 mA cm−2), high capacitance (2098 mF cm−2 at a current density of 1 mA cm−2), low resistance and excellent cycling stability, making them promising candidates for practical supercapacitor application. As a proof of concept, several MOF derived electrodes with different metal sources have also been prepared successfully via the same route, demonstrating the versatility of the proposed method for the preparation of binder-free carbon–metal oxide composite electrodes for electrochemical devices. © 2016 Elsevier Ltd

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2016

• Synergistic effects in 3D honeycomb-like hematite nanoflakes/branched polypyrrole nanoleaves heterostructures as high-performance negative electrodes for asymmetric supercapacitors

  Tang P.-Y., Han L.-J., Genç A., He Y.-M., Zhang X., Zhang L., Galán-Mascarós J.R., Morante J.R., Arbiol J. Nano Energy; 22: 189 - 201. 2016. 10.1016/j.nanoen.2016.02.019. IF: 11.553

  Rational assembly of unique branched heterostructures is one of the facile techniques to improve the electrochemical figure of merit of materials. By taking advantages of hydrogen bubbles dynamic template, hydrothermal method and electrochemical polymerization, branched polypyrrole (PPy) nanoleaves decorated honeycomb-like hematite nanoflakes (core-branch Fe2O3@PPy) are fabricated. X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM, and scanning transmission electron microscopy in high angle annular dark field mode with electron energy loss spectroscopy were combined to elucidate the mechanisms underlying formation and morphogenesis evolution of core-branch Fe2O3@PPy heterostructures. Benefiting from the stability of honeycomb-like hematite nanoflakes and the high conductivity of PPy nanoleaves, the resultant core-branch Fe2O3@PPy exhibits an ultrahigh capacitance of 1167.8 F g-1 at 1 A g-1 in 0.5 M Na2SO4 aqueous solution. Moreover, the assembled bi-metal oxides asymmetric supercapacitor (Fe2O3@PPy//MnO2) gives rise to a maximum energy density of 42.4 W h kg-1 and a maximum power density of 19.14 kW kg-1 with an excellent cycling performance of 97.1% retention after 3000 cycles at 3 A g-1. These performance features are superior than previous reported iron oxide/hydroxides based supercapacitors, offering an important guideline for future design of advanced next-generation supercapacitors. © 2016 Elsevier Ltd.

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