报告人：Professor Jun Li
Jun Li , Ph.D.
Professor
Department of Chemistry,Kansas State University
Manhattan, Kansas 66506, USA
junli@ksu.edu
题目：Nanoarchitectured Electrode Materials for Electrical Energy Storage
时间：2015年5月25日（星期一）9:00am
地点：独墅湖校区909号楼B厅
摘要：
Today’s high-performance electrochemical energy storage (EES) are represented by the high energy capacity of lithium-ion batteries (LIBs) and the high power and long cycle life of supercapacitors. At present, they are not able to be integrated into one system due to the distinct electrochemical mechanisms. The performance of the common electrode materials is limited by their low electrical conductivity and slow ion diffusion inside the electrode. In recent studies, we have demonstrated an effectiveapproach to overcome these two issues based on a three-dimensional nanostructured core-shell architecture consisting of ~100 � 200 nm thick coaxially coated electroactive materials (such as Si,1,2TiO2, and LiCoO2, and MnO2) on a highly conductive nanostructured current collector, i.e. vertically aligned carbon nanofiber arrays. In LIBs, this hybrid electrode structure allows mitigating the slow Li+diffusion by shortening the diffusion length in solid electrode materials. With proper deposition techniques, the shell materials can form finer nanoporous structures (such as nanoneedles, nanoflowers, etc.), further reducing the Li+diffusion length down to ~10 nanometers. In addition, it provides another benefit due to the significant pseudocapacitive contributions associated with the fast faradaic reactions at or near the electrode surface. As a result, these LIB electrodes present the features of a battery-supercapacitor hybridthat can offer high specific energy at very high power rates. For traditional supercapacitor materials such as MnO2,3,4this core-shell nanoarchitecture is able to significantly improve the current collecting capabilities and further enhance the power density by orders of magnitude. These studies demonstrated the potential for multi-scale nanostructured EES electrodes to achieve stable long charge-discharge cycles in the supercapacitor power regime (i.e. completing charging or discharging in less than 1 min.) while maintaining the battery-like high energy capacity.
References:
1.S. A. Klankowski, R. A. Rojeski, B. A. Cruden, J. Liu, J. Wu and J. Li,J. Mater. Chem. A, 2013, 1, 1055-1064.
2.S. A. Klankowski, G. P. Pandey, B. A. Cruden, J. Liu, J. Wu, R. A. Rojeski and J. Li,J. Power Sources, 2015, 276, 73-79.
3.J. Liu, J. Essner and J. Li,Chem. Mater., 2010, 22, 5022-5030.
4.S. A. Klankowski, G. P. Pandey, G. Malek, C. R. Thomas, S. L. Bernasek, J. Wu and J. Li,Nanoscale, 2015, In press.
个人简介：
Jun Li, Ph.D.
Professor
Kansas
State
University
Department of Chemistry
Manhattan,
KS
66506
-3701
E-mail: junli@ksu.edu
Tel: (785) 532-0955
Background
B.S., Chemistry, ’87, Wuhan University
Ph. D., Chemistry, ’95,
Princeton
University
Postdoctoral research associate, Cornell University, 1994-1997
Experience and Accomplishment
Dr. Jun Li has been engaged in research on nanosciences and nanotechnology through his career with Molecular Imaging Co. (1997-1998), the Institute of Materials Research and Engineering (Singapore, 1998-2000), NASA Ames Research Center (2000-2007), and Kansas State University (2007 � present).He has published over 140 peer-reviewed papers/book chapters and co-edited one book (Biosensors Based on Nanomaterials and Nanodevices). He is the inventor of 26 patent applications (7 issued).His research work in nanotechnology has been highlighted in over 40 public news reports. He received the first annualNano50 AwardbyNASA Tech Briefsunder Innovator category in 2005.
Dr. Li is a senior editor forIEEE Transactions on Nanotechnology,for which he served as an associate editor from 2007 to 2014.
Research Interests
Dr. Jun Li has been working on integrating nanomaterials, particularly carbon nanotubes and semiconductor/metal oxide nanowires, into functional devices including on-chip interconnects, thermal interface materials, solar cells, supercapacitors, Lithium-ion batteries, nanoelectrode array based biosensors, electrical neural interface, and nanoscale dielectrophoretic chips for capture and detection of bacterial and viral particles.
联系人：孙旭辉教授
