News & Events

MSE 520: Seminar Series

Each autumn, winter, and spring quarter, the department presents a series of weekly seminars on a broad range of interests, industries, and professions. MSE students and alumni are encouraged to attend. Graduate students are required to attend and receive MSE 520 credits for attending.

Quarter:
Fall 2019
Time:
Mondays, 3:30 p.m. - 4:20 p.m.
Location:
Johnson Hall 075 (unless specified)
Date Speaker
October 21

From molecules to megawatts – a journey from lab discovery to bankable products of new generation vanadium redox flow batteries through valley of death

Gary Yang

Technology innovation drives economic growth and social progress. Inventions in history—such as the steam engine, electricity, or the Internet—have radically changed the world. Meanwhile, there have been plenty of untold stories of inventions that never saw the light of day. Many potentially breakthrough ideas fall into the so-called technology “valley of death”, between academic achievements and industrial commercialization.

From lab research to bankable products is a long journey that goes through multiple technology readiness levels (TRLs), across concept development, technology validation, prototyping, product validation in the fields to design optimization. The long march to mature a technology is well exemplified in the development and advancement of a new generation vanadium flow battery (VFB). The new VFB chemistry was first conceived and developed at DOE’ Pacific Northwest National Laboratory in late 2010s. Its excellent electrochemical properties were subsequently validated at the lab scale. In 2012 UniEnergy Technologies (UET) was founded to commercialize the VRFB technology, with a mission to turn it into a rugged energy storage product for commercial, industrial and utility applications.

Scaling up the novel and compelling flow battery technology was challenging, requiring a highly specialized combination of electrochemical, chemical, mechanical, electric and controls engineering. Nonetheless, after over seven years of engineering optimization, productization, field demonstrations and design validation, UET has advanced the new generation VFB to deliver a safe, reliable and commercially competitive product for kW to MW scale applications.

This seminar will discuss the new generation VFB and share the experience and learnings of the journey from molecules to megawatts in advancing the new technology from lab discovery to a bankable product.

Dr. Zhenguo “Gary” Yang is a leading scientist and an entrepreneur in the field of electrochemical energy storage and conversion, particularly batteries and fuel cells. Aspired to turn lab discoveries into bankable products in markets, he has led efforts in commercializing several battery technologies. He founded Uni.Energy Technologies (UET) in 2012 and led the company successfully advancing a new generation vanadium flow battery (VFB) from molecules to MW scale systems for commercial, industrial and utility applications. Lately he has started taking on advanced micro-lithium batteries for targeted markets. Previously, Dr. Yang was a Lab Fellow at the US-DOE’ Pacific Northwest National Laboratory and led wide efforts in developing and demonstrating varied battery technologies including the VFB commercialized at UET, novel Li-ion and Na-salt chemistries. Earlier he was a leading scientist in solid oxide fuel cells and hydrogen storage. Dr. Yang has garnered several national and international awards, including the 2017 Presidential Green Chemistry Challenging Award.

October 28

Defect and interface engineering in electrode materials for metal ion batteries

Claire Xiong

Rechargeable batteries are promising energy storage technologies to provide high energy and high power for applications such as electric vehicles and electrical grids. Recent studies have shown enhanced electrochemical charge storage in electrodes that contain intentional structural defects (e.g., vacancies and interstitials) or with tailored interfaces. In this seminar, I will discuss recent works in my group including engineering defects in electrode materials through ion irradiation, and in operando electrochemical cycling, as well as interface engineering in nanostructured composite electrode and intergrowth electrode for metal ion batteries (e.g., Li ion and Na ion batteries). I hope to provide some perspectives regarding new pathways to design and engineering defects and interfaces in electrode materials with enhanced energy/power for rechargeable batteries.

Dr. Hui (Claire) Xiong is an Associate Professor in the Micron School of Materials Science and Engineering at Boise State University. Dr. Xiong received her BE degree in Applied Chemistry, MS degree in Inorganic Chemistry from East China University of Science and Technology, and her Ph.D. in Electroanalytical Chemistry from the University of Pittsburgh. Between 2008 and 2012, she conducted postdoctoral work at Harvard University and Argonne National Laboratory where her research involved electrochemical characterization of micro-fabricated cathode materials for micro-solid oxide fuel cells and the development of novel nanostructured electrode materials for rechargeable batteries. Dr. Xiong received NSF CAREER Award in 2015 and is a Scialog Fellow (2017-2019). Dr Xiong’s research focuses on design and development of nanoarchitectured and defect-driven electrode materials, mechanistic insights on electrolyte degradation, and ion irradiation effects on electrode materials for energy storage systems including Li-ion and Na-ion batteries.

November 4

Strain tuned topological phase transitions

Jiun-Haw ChuBand insulators with time reversal symmetry can be classified into normal insulators (NI), weak topological insulators (WTI) and strong topological insulators (STI) based on their Z2 topological indices. Changing Z2 indices requires closing and reopening the bandgap, and topologically distinct insulating phases are separated by a gapless Dirac or Weyl semimetal phase. The van der Waal layered material ZrTe5 is a prototypical example that the emergence of massive 3D Dirac fermions is due to its proximity to the STI-WTI phase boundary. In this talk, I will demonstrate that a STI-WTI topological phase transition can be induced by applying uniaxial stress to ZrTe5, and make the case that the in-situ tunable strain is a powerful tool to study and control topological materials and beyond.

Jiun-Haw Chu received his B.S. in Electronics Engineering from National Chiao Tung University and his Ph.D. in Applied Physics from Stanford University. He is currently an Assistant Professor in the Department of Physics at the University of Washington. His primary research goals are directed towards discovery and understanding of novel collective behaviors in quantum materials. Particular examples include unconventional superconductivity emerging near a quantum critical point, and exotic Weyl/Dirac excitations in semimetals with strong spin-orbit coupling. His research group focuses on crystal growth, thermodynamic and magnetic measurements, and novel experimental techniques that utilize strain to probe and manipulate the symmetry properties of materials.

November 11 No Seminar 
November 18

Elucidating the role of liquid crystallinity on conductive and mechanical properties of conjugated polymers

Enrique Gomez Polymers are poised to play an important role in various emerging optoelectronic applications, because they can combine chemical versatility, flexibility, stretchability, and mechanical toughness with dielectric or semiconducting properties. Nevertheless, in order to exploit their full potential, a clear description of how the structure, morphology, and macroscopic properties of polymers are interrelated is needed.

We propose that the starting point for understanding conjugated polymers includes a description of chain conformations and phase behavior; unfortunately, further efforts to measure these crucial characteristics are needed. Predictions and measurements of the persistence length of various conjugated polymers have significantly refined our intuition of the chain stiffness, and have led to predictions of the nematic coupling parameter and nematic-to-isotropic transitions. We show that the consequence of stiff backbones is a ubiquitous alignment layer near interfaces. Rheological measurements have led to refined estimates of the entanglement molecular weight and the glass transition temperature of both poly(3-alkylthiophenes) and push-pull copolymers, leading to new ways of thinking about how crystallites are interconnected within semicrystalline structures.

For example, our work suggests that liquid crystalline order is ubiquitous in conjugated polymers, and we have therefore developed an analytical description of how charge conduction depends on molecular weight for nematic polymers that agrees with experimental data. Current efforts continue to refine our knowledge of chain conformations and phase behavior and the factors that influence these properties, thereby enabling the design of novel optoelectronic materials based on conjugated polymers.

Enrique Gomez received his B.S. in Chemical Engineering from the University of Florida and his Ph.D. in Chemical Engineering from the University of California, Berkeley. After about a year and half as a postdoctoral research associate at Princeton University, he joined the Pennsylvania State University in August of 2009, where he is currently a full Professor of Chemical Engineering and Materials Science and Engineering. His research activities focus on understanding how structure at various length scales affects macroscopic properties of soft condensed matter. Much of the current work in the Gomez Group is focused on organic electronic materials, composites for battery electrolytes and cathodes, water filtration membranes, and plant cell walls. During his time at Penn State, Dr. Gomez has won multiple awards, including the Oak Ridge Associated Universities Ralph E. Powe Junior Faculty Enhancement Award, the National Science Foundation CAREER Award, and the Rustum and Della Roy Innovation in Materials Science Award.

November 25

Into the dark world of excitons & their quantum psychology: the case of the traumatic sudden separation

Keshav Dani About a decade ago, the discovery of monolayers of transition metal dichalcogenides opened a new frontier in the study of optically excited states in semiconductors, and related opto-electronic technologies. These materials exhibit a plethora of robust excitonic states, such as bright excitons at the K & K’ valleys, momentum- and spin-forbidden dark excitons, and hot excitons. Optics-based experiments have revealed much about the bright excitonic states, but they remain largely unable to access their valley character, their scattering channels into other valleys within the Brilloin Zone, and the nature of the dark states in these valleys.

Angle-Resolved Photoemission Spectroscopy (ARPES) based techniques would be ideal to access the valley character, and momentum-resolved scattering channels of photoexcited states in 2D semiconductors. But these are very challenging experiments to perform on the typically-available, micron-scale, 2D semiconductors. In my talk, I will discuss the challenges involved, and progress made in my lab to date towards this aim. Time permitting, we will end with an entertaining peek into the ‘quantum psychology of dark excitons’!

Keshav Dani is currently an Associate Professor at the Okinawa Institute of Science and Technology (OIST), Graduate University in Okinawa, Japan. He joined OIST in Nov. 2011 after completing a Director’s Postdoctoral Fellowship at Los Alamos National Laboratory. Keshav received his PhD from UC Berkeley, where he explored the nonlinear optical response of the quantum Hall system under the supervision of Daniel Chemla at LBNL. He obtained his BS from Caltech in Mathematics. His current research interests lie in the use of ultrafast techniques to study electron dynamics of two-dimensional materials and energy materials, develop optoelectronic applications in the terahertz regimes, and pursue interdisciplinary projects with OIST colleagues in neuroscience and art conservation.