Staff directory Xu Han

Xu Han

Fellowship Doctoral Student
China Scholarship Council
Universitat Autònoma de Barcelona (UAB)
xu.han(ELIMINAR)@icn2.cat
Advanced Electron Nanoscopy - Supramolecular NanoChemistry and Materials

Publications

2020

  • Monodisperse CoSn and NiSn Nanoparticles Supported on Commercial Carbon as Anode for Lithium- And Potassium-Ion Batteries

    Li J., Xu X., Yu X., Han X., Zhang T., Zuo Y., Zhang C., Yang D., Wang X., Luo Z., Arbiol J., Llorca J., Liu J., Cabot A. ACS Applied Materials and Interfaces; 12 (4): 4414 - 4422. 2020. 10.1021/acsami.9b16418. IF: 8.456

    Monodisperse CoSn and NiSn nanoparticles were prepared in solution and supported on commercial carbon black. The obtained nanocomposites were applied as anodes for Li- and K-ion batteries. CoSn@C delivered stable average capacities of 850, 650, and 500 mAh g-1 at 0.2, 1.0, and 2.0 A g-1, respectively, well above those of commercial graphite anodes. The capacity of NiSn@C retained up to 575 mAh g-1 at a current of 1.0 A g-1 over 200 continuous cycles. Up to 74.5 and 69.7% pseudocapacitance contributions for Li-ion batteries were measured for CoSn@C and NiSn@C, respectively, at 1.0 mV s-1. CoSn@C was further tested in full-cell lithium-ion batteries with a LiFePO4 cathode to yield a stable capacity of 350 mAh g-1 at a rate of 0.2 A g-1. As electrode in K-ion batteries, CoSn@C composites presented a stable capacity of around 200 mAh g-1 at 0.2 A g-1 over 400 continuous cycles, and NiSn@C delivered a lower capacity of around 100 mAh g-1 over 300 cycles. Copyright © 2020 American Chemical Society.


2019

  • In Situ Electrochemical Oxidation of Cu2S into CuO Nanowires as a Durable and Efficient Electrocatalyst for Oxygen Evolution Reaction

    Zuo Y., Liu Y., Li J., Du R., Han X., Zhang T., Arbiol J., Divins N.J., Llorca J., Guijarro N., Sivula K., Cabot A. Chemistry of Materials; 31 (18): 7732 - 7743. 2019. 10.1021/acs.chemmater.9b02790. IF: 10.159

    Development of cost-effective oxygen evolution catalysts is of capital importance for the deployment of large-scale energy-storage systems based on metal-air batteries and reversible fuel cells. In this direction, a wide range of materials have been explored, especially under more favorable alkaline conditions, and several metal chalcogenides have particularly demonstrated excellent performances. However, chalcogenides are thermodynamically less stable than the corresponding oxides and hydroxides under oxidizing potentials in alkaline media. Although this instability in some cases has prevented the application of chalcogenides as oxygen evolution catalysts and it has been disregarded in some others, we propose to use it in our favor to produce high-performance oxygen evolution catalysts. We characterize here the in situ chemical, structural, and morphological transformation during the oxygen evolution reaction (OER) in alkaline media of Cu2S into CuO nanowires, mediating the intermediate formation of Cu(OH)2. We also test their OER activity and stability under OER operation in alkaline media and compare them with the OER performance of Cu(OH)2 and CuO nanostructures directly grown on the surface of a copper mesh. We demonstrate here that CuO produced from in situ electrochemical oxidation of Cu2S displays an extraordinary electrocatalytic performance toward OER, well above that of CuO and Cu(OH)2 synthesized without this transformation. © 2019 American Chemical Society.