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Engineering Nanomaterials and Interfaces for Energy Conversion and Storage

发布时间: 2009-07-14 13:54 | 【 【打印】【关闭】
SEMINAR
The State Key Lab of
High Performance Ceramics and Superfine Microstructure
Shanghai Institute of Ceramics, Chinese Academy of Sciences
 
 
 
Engineering Nanomaterials and Interfaces for Energy Conversion and Storage
 
 Speaker
 Prof. Dr. Guozhong Cao(曹国忠教授)
 
University of Washington, Department of Materials Science and Engineering, Seattle, USA
 
 
 时间:77 (星期二)上午9:30
 
地点:2号楼607会议室
 
联系人:   , 归林华
 
Abstract: The increasing demand for fossil fuels and the environmental impact of their use are continuing to exert pressure on an already-stretched world energy infrastructure. Significant progress has been made in the development of renewable-energy technologies, such as solar cells, fuel cells, and bio-fuels.  However, although these alternative energy sources have been marginalized in the past, it is expected that new technology could make them more practical and price competitive with fossil fuels, thus enabling an eventual transition away from fossil fuels as our primary energy sources. The last decade has brought significant progress in cleaner and more efficient energy technology. However, further development is limited by the properties of existing materials. For example, thermoelectric materials typically possess low power conversion efficiency due to inherent coupling of charge and heat transfer in existing materials. Likewise, portable electric power sources, such as batteries, have low power density due to limited electrode kinetics or mass transport. A recent promising avenue of research has been nanostructured materials, which have demonstrated significantly enhanced energy conversion efficiency in batteries, thermoelectrics, catalysis, and solar cells, due partly to their large surface to volume ratios and favorable transport properties.
 
In this presentation, I will use three examples to illustrate how energy conversion and storage efficiency can be significantly improved through careful design and engineering of materials in the nanometer and micrometer scales and through surface chemistry modification. The first example is popcorn-style dye-sensitized solar cells, in which the controlled micro-sized aggregation of nanocrystallites resulted in light scattering inside the photoelectrode. This led to a greater than 200% enhancement in the power conversion efficiency and to a 40% reduction in the amount of photoelectrode. The second example is nanostructured or hierarchically structured electrodes for lithium-ion batteries. Nanostructured and hierarchically structured electrodes have demonstrated specific energy and specific power improvements of up to 2 orders of magnitude. Further enhancement can be achieved through modifications in the surface chemistry, crystallinity and crystal structure. The last example is the tuning of a dehydrogenation reaction through surface chemistry modification and by confining the hydrides inside the nanopores of a highly porous carbon scaffold.
 
 
报告人简介:Dr. Guozhong Cao is Boeing-Steiner Professor of Materials Science and Engineering and Adjunct Professor of Chemical and Mechanical Engineering at the University of Washington, Seattle, WA. He received his PhD degree from Eindhoven University of Technology (the Netherlands), MS from Shanghai Institute of Ceramics, and BS from East China University of Science and Technology (China). Dr. Cao has published over 250 refereed papers, authored and edited 5 books and 3 conference proceedings, and presented over 100 invited talks, keynote speeches, and seminars. His research has spun off two startup companies. Currently, Dr. Cao serves as the editor of Annual Review of Nano Research and associate editor of Journal of Nanophotonics. His recent research is focused mainly on nanomaterials for energy related applications including solar cells, lithium-ion batteries, supercapacitors, and hydrogen storage.