Seminar Schedule

We're excited to announce our first CEEC workshop. Prof. Byungha Shin from KAIST will deliver a tutorial lecture on X-ray photoelectron spectroscopy (XPS). The lecture should be beneficial for both new users and more experienced users, and it is not focused on electrochemical systems specifically. Please feel free to share this notice with other students you know who might be interested in learning more about XPS.

Picture of Prof. Shin

Bio of Prof. Shin:  Byungha Shin is an Associate Professor in the Department of Materials Science (MSE) and Engineering at Korea Advanced Institute of Science and Technology (KAIST) in Daejeon, Korea. Prof. Shin received B.S. in MSE from Seoul National University in 2000, M.S. in MSE from the University of Michigan in July 2002, and Ph.D. in Applied Physics from Harvard University in 2007. From May 2007 to March 2010, he was a post-doctoral researcher in the Department of MSE at Stanford University. From May 2010 until he joined KAIST in Feb 2014, he worked at IBM T. J. Watson Research Center in as s post-doctoral research and a Research Staff Member. His past research experience includes the study of thin film growth kinetics and high-k dielectric materials for microelectronic applications. His primary research interest is developing novel materials for energy applications with the current emphasis on hybrid perovskite optoelectronic devices (PV and LED), chalcogenide thin film solar cells, and photoelectrochemical water splitting.

 

Jack Davis

Ph.D. Candidate in Chemical Engineering

Advisor: Daniel Esposito

High-speed imaging of bubble flows in membraneless electrochemical cells

As solar electricity continues to increase in installed capacity, significant research efforts have focused on energy storage devices to provide renewable electricity during intermittent hours. One promising energy storage technology is water electrolysis, which uses water and electricity to generate hydrogen fuel. A major challenge for electrochemical hydrogen production is the capital cost, which for state-of-the-art devices is still prohibitively high. Membraneless electrolyzers have been proposed as a low-cost reactor design for water electrolysis. The design of these devices is a significant departure from the architectures of conventional membrane- electrode assembly (MEA) and alkaline electrolyzers. In order to safely and efficiently separate the product gases, many of these membraneless designs require flowing electrolyte. In this study, we use high-speed video and image processing to quantitatively characterize the multiphase flow in a reactor scheme using angled mesh flow-through electrodes. While it is generally recognized that the dynamics of multiphase flow can strongly impact cell performance, attempts to characterize gas evolving electrodes can be non-trivial due to the complexity of the underlying physics. Through a post-processing analysis, we are able to detect the size, location, and velocity of the hydrogen bubbles generated during operation. This non-invasive technique can be used to quantify gas evolution efficiency yields, bubble size distributions, current distributions, and product gas cross-over. These techniques can be applied to monitor operating conditions as well as guide the design of future electrolysis systems.


Nick Brady

Ph.D. Candidate in Chemical Engineering

Advisor: Alan West

Applications of Data Science in Battery Science: Quantitative Parameter Estimation, Model Selection, and Variable Selection

Moore's Law has led to increasing computational capabilities available at extremely low costs. The cheapness of computer resources allows for the generation of vast amounts of data from physics-based numerical models. In parallel, there have been innovative methodologies developed that allow computer algorithms to perform data analysis and decision making that traditionally could only be performed by humans with technical expertise. This talk will illustrate how physics-based battery models can be coupled with algorithmic techniques to perform improved parameter estimation, model selection, variable selection, and to assist in the design of experiments. 

Reimagining the Electrochemical Design Space

Abstract: Electrochemical devices such as electrolyzers, batteries, and photoelectrochemical cells have tremendous potential to contribute to a sustainable energy future thanks to their ability to convert solar- and wind-derived electricity into storable chemical bonds that can be converted back to electricity at a later time. Despite the positive attributes of electrochemical technologies, only a very small percentage of society’s total energy usage flows through them, reflecting the fact that significant improvements in the performance and/or cost of many of these technologies are required to compete with the conventional fossil fuel-based energy system. This need for step change improvements in performance and cost warrants—one might even say requires—that electrochemists and electrochemical engineers reimagine the design space that currently constrains the materials and device architectures that are the basis of today’s commercial electrochemical technologies. Towards this end, I will give a general overview of the “control knobs” that are often considered in the design and operation of electrochemical technologies. Next, I will give a few examples of projects from our lab where we have introduced new control knobs and/or different combinations of control knobs to electrolysis systems for solar fuels production in ways that create new design spaces that can allow these technologies to achieve new functionalities and/or expand the limits of achievable performance or cost. 

Esposito

Bio: Prof. Esposito received his Ph.D. in Chemical Engineering at the University of Delaware and studied as a postdoctoral research associate at the National Institute of Standards and Technology (NIST) under a National Research Council fellowship.  He is now an Associate Professor in Chemical Engineering at Columbia University, where his group’s research interests relate broadly to electrochemical energy technologies. Specific topics of interest include solar fuels, electrocatalysis, photoelectrochemistry, electrochemistry at buried interfaces, membrane-free electrolyzers, and the use of in situ analysis techniques to study the performance and properties of electrode materials at high spatial resolution.

Jake Russell

Ph.D. Candidate in Chemistry

Advisor: Xavier Roy

High performance organic pseudocapacitors by molecular design

By storing energy from electrochemical processes at the electrode surface, pseudocapacitors bridge the performance gap between electrostatic double-layer capacitors and batteries. In this context, molecular design offers the exciting possibility to create tunable and inexpensive organic electroactive materials. Here I will give a brief overview of the history and mechanisms of pseudocapacitors, and then describe a recently designed porous material composed of perylene diimide (PDI) and triptycene subunits which demonstrates remarkable performance as a pseudocapacitor electrode material. I will show how we can alter the performance of the material, from battery-like (storing more charge at low rates) to capacitor-like (faster charge cycling), by modifying the structure of the pores via flow photocyclization.

Jake Image

Anna Dorfi

Ph.D. Candidate in Chemical Engineering

Advisor: Daniel Esposito

High-throughput Scanning Electrochemical Microscopy based on Nonlocal Continuous Line Probes

Scanning electrochemical microscopy (SECM) is a chemical imaging technique that has been used in a variety of fields to study micro- and nano-scale processes, interactions, and materials. However, conventional SECM is carried out using a “point probe” ultramicroelectrode that is scanned across the sample in a laborious point-by-point sampling scheme that requires excessively long scan times to image large areas with high resolution. Long scan times limit instrument throughput and can lead to unwanted changes in the sample or probe. In order to address this issue, our lab is exploring the use of a home-built scanning electrochemical microscope capable of achieving high areal imaging rates through the use of continuous line probes (CLPs) and compressed sensing (CS) image reconstruction. The CLP is a non-local probe consisting of a band electrode, where the achievable spatial resolution is set by the thickness of the band and the achievable imaging rate is largely determined by its width. A combination of linear and rotational motors allows for CLP scanning of substrates at different angles over areas up to 25 cm2 to generate the raw signal necessary to reconstruct the desired electrochemical image using CS signal analysis algorithms. We believe using this electrochemical microscope setup for use with nonlocal probes will allow for more efficient electrochemical imaging and higher throughput testing of electroactive materials, thereby promoting the accelerated discovery of materials for a variety of applications.

Commercialization of the Rechargeable Manganese Dioxide - Zinc Alkaline Battery Chemistry: A Story of Scale Up

Abstract: Batteries, regenerative fuel cells, supercapacitors represent electrical energy storage technologies for matching energy consumption with production especially for the integration of renewable sources. More than a century of research has identified hundreds of electrochemical redox active electrical energy storage materials, the most notable are Zn-MnO2 primary batteries and lead-acid, nickel-cadmium, lithium-ion secondary batteries. Despite important advances, utility scale electrochemical energy storage technologies are too expensive on a price per energy unit per cycle basis to be used at large scale. The basis materials of batteries for large-scale storage must be low-cost, earth-abundant, and safe at the desired scale. The alkaline MnO2 cathode, typically found in low-cost consumer primaries, fulfills these requirements. The U.S. Department of Energy ARPA-E goals for large-scale storage are less than $0.10 per kWh per cycle and efficiency of the battery. A standard cylindrical alkaline cell costs roughly $20 per kWh. Thus an alkaline cell is a sufficiently inexpensive basis for large-scale storage. However, in this case an extended cycle life becomes the relevant engineering challenge. In this presentation the process of converting a research lab discovery to a fully manufacturable product targeted at a specific market will be discussed.

Bio: Alexander Couzis is the Herbert G. Kayser Professor in chemical engineering at The City College of New York (CCNY) and Chief Technology Officer of Urban Electric Power (UEP). Dr. Couzis received his BS in chemical engineering from the National Technical University, Athens, Greece and MS and PhD degrees in chemical engineering from The University of Michigan in Ann Arbor, MI. Immediately after his graduation he joined International Paper's research center with the division of Applied Polymer Science developing novel polymeric materials and coatings for gas and vapor barrier applications. In September 1994, he joined the department of Chemical Engineering at CCNY where he established an internationally recognized research program focused on the study of the dynamic phenomena at solid-liquid interfaces, templated synthesis of nanoparticles and nanoparticle structures. He is the author of over 50 peer reviewed highly sited publications, holds 5 patents, and has mentored 15 PhD students. From 2008 to 2013 Pr. Couzis held the position of Department chair of chemical engineering at CCNY. In January 2013 he went on special leave from the university and joined Urban Electric Power (www.urbanelectricpower.com), a new rechargeable battery chemistry startup company that spun out from the department. UEP is commercializing the advanced zinc anode rechargeable battery technology first developed at the CUNY Energy Institute with funding from ARP A-e. Since, he has served as the chief technical officer for the company. In November 2014 the board appointed him chief executive officer as well as CTO. He kept the CEO position for 2 ½ years. After five years with the company he has returned to his duties at the city College of New York, while still retaining the CTO title at UEP.

Jon Vardner
PhD Candidate in Chemical Engineering
Advisor: Alan West

Measurement of VO2+ Transference Number in Nafion with Varying Concentrations of Sulfuric Acid

Crossover in Vanadium Redox Flow Batteries (VRFB) has an important impact on performance and is dependent on several physical properties, including the transference number. In this work, model-guided design of experiment was used to determine vanadium transference number in fully-hydrated ion-selective membranes, while minimizing uncertainties related to unknown or unmeasured properties. The transference number of VO2+ in Nafion 117 for varying ratios of H2SO4 to VOSO4 was measured, and the analysis showed that the transference number estimate can be obtained with 5% or less uncertainty. The VO2+ transference number sharply decreased as acid was added to the electrolyte. The variation in the transference number with the ratio of H2SO4 to VOSO4 was fit to a model to obtain the product of the ratio of vanadium-to-proton partition and diffusion coefficients.

 

Measurement of VO2+ Transference Number in Nafion with Varying Concentrations of Sulfuric Acid

Steven Denny
PhD Candidate in Chemical Engineering
Advisor: Jingguang Chen


Electrochemical stability and hydrogen evolution activity of bare and platinum-modified tungsten and niobium nitrides


Transition metal nitrides are a class of electrocatalyst supports with similar physical and electronic properties to those of carbides. While transition metal carbides have demonstrated electrocatalytic stability and activity for a variety of industrially relevant reactions, these materials often have graphitic overlayers that curtail activity and can impede accurate computational modelling for high surface area catalysts. Nitride analogues are inherently “clean” in that they do not have carbonaceous overlayers, which may further capitalize the application of Density Functional Theory (DFT) calculations of interactions between supported metal and nitride substrates. Demonstrated in this study is the stability behavior of tungsten nitride (WN) and niobium nitride (NbN) thin films over a wide pH region between 1 and 13, from which pseudo-Pourbaix diagrams are made to exhibit surface passivation and oxidation behavior. Furthermore, the hydrogen evolution reaction (HER) is used as a probe reaction. The HER activity of Pt-modified WN and NbN is assessed in both acid and alkaline electrolyte in conjunction with DFT-calculated hydrogen binding energies.

If you would like to nominate a student, faculty, or industry professional to present at a seminar, please email lea.winter@columbia.edu.

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