报告内容摘要

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This presentation will introduce recent progress of our group on transition metal oxide materials for electrocatalysis and batteries. The first example is the synthesis of ultrathin MnO2 nanoflakes. We found that CTAB can be a very effective surfactant for controlling MnO2 particle size. The ultrathin flakes service well as the ORR catalysts when supported on carbon. They give a high mass efficiency as compared to all other similar materials. These flakes can also serve as the standard active materials for making different MnO2/C supercapacitors with different carbons. We are able to compare these carbons and found that the carbon supports indeed affect the capacitance contribution from the active MnO2 material. In addition, the microstructure design of several electrode materials for Li-S, Li-ion, and Na-ion batteries will be discussed as well. The first example is a tube-in-tube carbon structure for incorporating S. The structure is able to offer a high S loading and stable performance. The outer carbon layer prevents the dissolution of S into the electrolyte. The structure is further modified with reserved interior void space to accommodate the large volume expansion of metal oxide anodes, such as SnO and Fe2O3, during cycling of conversion reactions with Li and Na. In addition, we also employed the in-situ X-ray absorption near edge spectroscopic (XANES) approaches to investigate the conversion reaction of FeOOH with Li. The approach can be extended to investigate the reaction of FeOOH with Na as well.

 

References

1) C. Wei, L. Yu, C. Cui, J. Lin, C. Wei, N. Mathews, F. Huo, T. Sritharan, Z. Xu, Chem. Comm., 2014, 50, 7885

2) C. Wei, P. S. Lee, Z. Xu, RSC Adv., 2014, 4, 31416-31423. Invited Research Article

3) Linghui Yu, Shibo Xi, Chao Wei, Wenyu Zhang, Yonghua Du, Qingyu Yan, Zhichuan J. Xu, Superior Lithium Storage Properties of β–FeOOH, Advanced Energy Materials, 2014, 1401517

4) Yi Zhao, Wangliang Wu, Jiaxin Li, Zhichuan Xu, Lunhui Guan, Encapsulating MWNTs into hollow porous carbon nanotubes: A tube-in-tube carbon nanostructure for high performance lithium sulfur batteries, Advanced Materials, 2014, 26, 5113-5118

5) Yi Zhao, Chao Wei, Linghui Yu, Luyuan Paul Wang, Zhichuan J. Xu, Reserving interior void space for volume change accommodation: an example of cable-like MWNTs⊙SnO2⊙C composite for superior lithium and sodium storage, Advanced Science, 2015, DOI: 10.1002/advs.201500097

报告人简介

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Dr. Zhichuan Xu is currently an assistant professor in the School of Materials Science and Engineering at Nanyang Technological University. Dr. Xu received his PhD training from Lanzhou University, Institute of Physics, CAS, and Brown University (2002-2008). His PhD study focused on nanomaterials synthesis and characterizations. He worked in State University of New York at Binghamton as a Research Associate (2007-2009) and then he worked in Massachusetts Institute of Technology as a Postdoctoral Researcher (2009-2012). Dr. Xu's research interests include electrochemistry, catalysis, solar fuels, energy storage, magnetic nanomaterials, and sensors.

 

联系人：冯翠云 62756702