报告题目：Smooth Deposition and Stable Cyclability of Lithium Metal Batteries through Electrolyte Strategy
报告人：Prof. Wu Xu, Pacific Northwest National Laboratory
Dr. Wu Xu is currently a Chief Scientist in the Energy Processes & Materials Division, Energy and Environment Directorate, Pacific Northwest National Laboratory (PNNL) located in Richland, Washington State, United States. He obtained his Ph.D. from the National University of Singapore in early 2000. He has expertise and extensive experience for more than 25 years in the development of novel electrolytes for different kinds of energy storage devices (Li-ion batteries, Li-air batteries, Li-metal batteries, supercapacitors, and organic redox flow batteries), the development of electrode (both cathode and anode) materials, the protection of Li metal anode, and the study of electrode/electrolyte interfaces. Since joining PNNL in April 2008, Dr. Xu has been leading the projects on Li-ion battery electrolyte development, Li-metal anode and rechargeable Li-air batteries. From early 2004 to March 2008, Dr. Xu worked as a Senior Scientist in the Electrolyte Business Group of Ferro Corporation located in Independence, Ohio. Before that, he was a Faculty Research Associate/Postdoctoral Research Fellow in the group of Professor Austen Angell, Department of Chemistry and Biochemistry, Arizona State University. He had previously worked in Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences for 7 years before he went to pursue his doctoral degree in National University of Singapore. Dr. Xu has more than 130 papers published in peer-reviewed professional journals (including 2 papers in Science, 3 in Nature sub-journals – Nature Nanotechnology, Nature Energy, Nature Communications), 1 book, 5 book chapters, 25 U.S. patents granted, and other 11 patents pending. He has received several awards including 2013 PNNL Inventor-of-the-Year, 2012 R&D 100 Award, and so on.
Lithium (Li) metal batteries have been regarded as the most promising candidate for next generation energy storage because Li metal as anode has extremely high theoretical specific capacity (3860 mAh g-1), the lowest negative electrochemical potential (-3.040 V vs. the standard hydrogen electrode) and low density (0.534 g cm-3). However, the safety concerns and the short cycle life due to Li dendrite growth and low Coulombic efficiency (CE) hinder the development and practical applications of rechargeable Li metal batteries. During the past four decades, lots of approaches have been reported to suppress the Li dendrite growth and to improve the stability of Li metal anode, including using Li alloys, solid-state electrolytes, polymer electrolytes, ionic liquids, highly concentrated liquid electrolytes, additives, protecting layers, interlayers between Li and separator, nanoscale design, Li-reduced graphene oxide composites, and so on. However, the improvement on Li anode as far is still unsatisfactory. In the past six years, we at PNNL systematically investigated various strategies to suppress Li dendrite growth, increase Li CE and enhance Li structural stability through electrolyte development, separator modification, 3D structured Li hybrid anode, etc. In this talk, the electrolyte strategy will be discussed and the details of the investigations will be reported at the presentation.