题目1：Synthesis of Hollow Nanostructures for Electrochemical Energy Storage

报告人：Prof. Xiong Wen (David ) Lou
　　　　（School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore）
 

题目2：Electrochemical reactions in electrode materials of lithium-ion battery: Ex-situ/in-situ TEM studies

报告人：Wei Zhang
　　　（Sustainable Energy Technologies Department, Brookhaven National Laboratory）

时间：12月14日（周三）9: 00-11: 30

地点：李薰楼468会议室 

报告1简介：

Synthesis of Hollow Nanostructures for Electrochemical Energy Storage

Xiong Wen (David ) Lou
School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
Email: xwlou@ntu.edu.sg

Abstract:

Hollow nanostructures are promising as electrode materials for electrochemical energy storage, including lithium-ion batteries, supercapacitors and lithium-sulfur batteries. In this talk, I will briefly discuss the design,  synthesis and electrochemical properties of hollow nanostructures of metal oxides/sulfides. Specifically, we have been able to synthesize different hollow nanostructures of many binary metal oxides such as SnO₂, Fe₂O₃ and Fe₃O₄, and many mixed transition metal oxides/sulfides such as NiCo₂O₄ and NiCo₂S₄. We have also designed carbon hollow structures to fabricate advanced cathode materials for lithium-sulfur batteries. Most recently, we also designed some advanced hollow structures of carbon-metal oxide including MnOx-carbon and TiOx-carbon for lithium sulfur batteries.  

References:

[1]  Z. Y. Wang, L. Zhou, X. W. Lou, Metal oxide hollow nanostructures for lithium-ion batteries, Adv. Mater.  2012, 24, 1903 – 1911.
[2]  L. F. Shen, L. Yu, H. B. Wu, X. Y. Yu, X. G. Zhang, X. W. Lou, Formation of nickel cobalt sulfide ball-in-ball hollow spheres with enhanced electrochemical pseudocapacitive properties, Nat. Commun., 2015, 6, 6694. 
[3] Z. Li, J. T. Zhang, B. Y. Guan, D. Wang, L. M. Liu, X. W. Lou, A new sulfur host based on metallic and polar TiO@carbon hollow spheres for advanced lithium-sulfur batteries, Nat. Commun., 2016, 7, 13065.
[4]  Z. Li, J. T. Zhang, X. W. Lou, Hollow carbon nanofibers filled with MnO₂ nanosheets as a highly efficient sulfur host for lithium-sulfur batteries with high energy density and long cycle life, Angew. Chem. Int. Ed. 2015, 54, 12886 – 12890.
[5]   H. Hu, B. Y. Guan, B. Y. Xia, X. W. Lou, Designed formation of Co₃O₄/NiCo₂O₄ double-shelled nanocages with enhanced pseudocapacitive and electrocatalytic properties, J. Am. Chem. Soc., 2015, 137, 5590 – 5595.

Biography:

Dr. David Lou received his B.Eng. (1st class honors) (2002) and M.Eng. (2004) degrees from the National University of Singapore. He obtained his Ph.D. degree in chemical engineering from Cornell University in 2008. Right after graduation, he joined Nanyang Technological University (NTU) as an Assistant Professor. He was promoted to Associate Professor since September 2013, and to Full Professor since September 2015. He has published about 240 papers with a total citation of >31,500 (ISI) or >37,000 (Google scholar), and an h-index of 104 (ISI) and 113 (Google scholar). His main research interest is on designed synthesis of nanostructured materials for energy and environmental applications. In particular, he has strong interest on synthesis of hollow nanostructures for different applications, such as, lithium-ion batteries and supercapacitors. He also explores the applications of novel nanostructured materials for electrocatalysis and photocatalysis. He has received several important awards including the Young Scientist Award 2012 by National Academy of Science of Singapore. He also received the Nanyang Research Award 2012 by Nanyang Technological University. He was listed as a Highly Cited Researcher by Thomson Reuters in 2014 (in Materials Science) and 2015 (in both Materials Science & Chemistry) and 2016 (in Materials Science, Chemistry, & Environment).  He is currently an Associate Editor for Journal of Materials Chemistry A.

报告2简介：

Electrochemical reactions in electrode materials of lithium-ion battery: Ex-situ/in-situ TEM studies

Wei Zhang
　　　Sustainable Energy Technologies Department, Brookhaven National Laboratory

Abstract:

The development of new electrodes for next-generation Li-ion batteries requires fundamental understanding of how electrodes function by investigating the electrochemical reactions in individual particles in a working electrode. Transmission electron microscopy (TEM) based techniques are powerful for probing charge/discharge dynamics of bulk electrodes with high spatial resolution. Especially the latest development of in-situ TEM techniques provides new opportunities to study the electrochemical reactions in a real battery system. Here, we report our recent results from the development and application of ex-situ/in-situ TEM methods in unraveling the complex and dynamic processes of ionic transport in single nanoparticles of working electrodes. Examples will be provided to the studies of ionic transport in single Li_xFePO₄, Fe₃O₄ and Li₄Ti₅O₁₂ nanoparticles upon charge and discharge, showing the direct evidences of the coupling between local ionic displacement/ordering with phase transformations. The observation may offer a generic explanation of the structure-determined ionic transport and electrochemical reactions in intercalation and conversion type electrodes.

Biography:

Wei Zhang is a research associate in the Sustainable Energy Technologies Department of Brookhaven National Laboratory.  He obtained his Ph.D. from Institute of Metal Research, Chinese Academy of Sciences in 2013 and then joined Brookhaven National Laboratory as a research associate. Before moving to the United States, he attended University of Science and Technology Beijing in China and graduated with a Bachelor of Science degree in 2006. His research interests center on TEM studies on electrode materials including metal oxides, spinel and olivine compounds.