報告題目：Revealing corrosion chemistry in lithium ion battery and beyond—a tale of two cities
報 告 人：Huolin Xin (Brookhaven National Laboratory)
報告時間：2015年12月22日下午15：00
報告地點：化學樓二樓一號會議室
報告人簡介：
Huolin Xin is an associate scientist in the Center for Functional Nanomaterials at Brookhaven National Laboratory. He is also an adjunct faculty member at SUNY Stony Brook University. His primary field of expertise lies in developing novel 3-D, atomic-resolution, and in situ spectroscopic and imaging tools to probe the structural, chemical, and bonding changes of energy materials during chemical reactions or under external stimuli. His research spans the areas from tomographic and atomic-resolution chemical imaging of fuel cell nanoparticles to in situ environmental study of heterogeneous catalysts and battery materials, all maintaining a strong focus on nanocharacterization of energy materials. In 2008, 2010, 2011, and 2012, he received Distinguished Scholar Award, Castaing Award, and Presidential Scholar Award from professional EM societies. His work on battery materials has been selected as the 2014's Top-10 Scientific Achievements by Brookhaven Lab. His research has resulted in more than 70 peer-reviewed publications and 1 patent, more than ten of which have been reported and highlighted by national media agencies. In his first year of being an independent PI at Brookhaven Lab, he published 14 journal articles. Five of which were published in Science and Nature sister journals. Of two of the five, he is the corresponding author. He currently operates a group consisting of one master student, one domestic Ph.D. student, and one foreign exchange Ph.D. student. To date, he has graduated three master students. His first group alumni won the “Presidential Student Award” at M&M 2014 based on her master thesis study of high-throughput model-based tomographic reconstructions.
報告簡介：
Tailoring the surface chemistry to enhance corrosion resistance lies at the heart of materials processing for corrosion control of structural materials. This conventional wisdom, however, can fail miserably when the underlying materials’ function(s) involves chemical reactions. In this talk, I will introduce the concepts of surface passivation and passivity breakdown. I will show that, by tuning the surface composition, passivation can lead to successful optimization of cathode materials in lithium ion batteries (LIBs). On the other hand, self-passivation in anode materials can significantly alter the rate performance of LIBs. I will show that the rate capacity of a large family of phase conversion anode materials, i.e. transition metal oxides, is dependent on the stochastic process of passivity breakdown which can be described by a Poisson model. This model can answer the long standing question—why transition metal oxides conversion materials perform much more poorly in sodium ion batteries than in LIBs, even though sodium ions can diffuse equally fast as lithium does in these materials.
