Unleashing the Full Potential of Batteries: Modeling, Learning, and Control
Scott Moura, Associate Professor | Director of eCAL, University of California, Berkeley
Batteries are ubiquitous. However, today’s batteries are expensive, range-limited, power-restricted, die too quickly, charge too slowly, and susceptible to safety issues. For these reasons, advanced model-based battery management systems (BMS) are of extreme interest. In this talk, we discuss eCAL’s recent research electrochemical-based BMS, which are modeled by nonlinear partial differential equations (PDEs). Specifically, we discuss (i) optimal experiment design for learning, and (ii) optimal safe-fast charging control. Finally, we close with exciting new perspectives for next-generation battery systems.
Scott Moura is an Associate Professor in Civil & Environmental Engineering and Director of the Energy, Controls, & Applications Lab (eCAL) at the University of California, Berkeley. He is also a faculty member at the Tsinghua-Berkeley Shenzhen Institute. He received the B.S. degree from the University of California, Berkeley, CA, USA, and the M.S. and Ph.D. degrees from the University of Michigan, Ann Arbor, in 2006, 2008, and 2011, respectively, all in mechanical engineering. From 2011 to 2013, he was a Post-Doctoral Fellow at the Cymer Center for Control Systems and Dynamics, University of California, San Diego. In 2013, he was a Visiting Researcher at the Centre Automatique et Systèmes, MINES ParisTech, Paris, France. His research interests include control, optimization, and machine learning for batteries, electrified vehicles, and distributed energy resources.
Dr. Moura is a recipient of the National Science Foundation (NSF) CAREER Award, Carol D. Soc Distinguished Graduate Student Mentor Award, the Hellman Fellowship, the O. Hugo Shuck Best Paper Award, the ACC Best Student Paper Award (as advisor), the ACC and ASME Dynamic Systems and Control Conference Best Student Paper Finalist (as student and advisor), the UC Presidential Postdoctoral Fellowship, the NSF Graduate Research Fellowship, the University of Michigan Distinguished ProQuest Dissertation Honorable Mention, the University of Michigan Rackham Merit Fellowship, and the College of Engineering Distinguished Leadership Award.
Harvesting Energy from Aluminum Waste
Peter Godart, PhD Candidate, Department of Mechanical Engineering, MIT
Aluminum is the third most abundant element on earth and is widely used in nearly every industry. In nature, aluminum is found primarily in its various oxidized forms as bauxite ore, and reducing this ore is a highly energy- and carbon-intensive process. Currently global recycling rates are limited by complications with sorting waste by alloy content, lack of economic incentive, and the recent restriction of waste exports to other countries. As a result, several million tons of aluminum are landfilled each year in the US alone, leaving a significant amount of potential energy sitting idle and unused. A new alternative strategy to managing this waste is to turn it into an energy-dense fuel that reacts exothermically with water to produce hydrogen and boehmite, a valuable byproduct used in various industrial and pharmaceutical processes. When exposed to air, bulk aluminum develops an oxide layer that prevents it from reacting with water at practical temperatures; however, recent research at MIT has shown that a minimal surface treatment of gallium and indium can disrupt the oxide layer at the grain boundaries, allowing this reaction to proceed to >95% completion. In this talk, the science underlying this treatment process will be presented, as well as several systems we have developed that use this fuel to generate electricity up to the 10 kW scale and power seawater desalination.
Peter Godart is a fourth-year PhD candidate at MIT in the Department of Mechanical Engineering. He holds B.S. degrees in mechanical and electrical engineering and an M.S. degree in mechanical engineering from MIT. After earning his bachelor’s degrees in 2015, Peter spent two years as a research scientist at the NASA Jet Propulsion Laboratory, where he worked daily operations for the Curiosity Mars Rover, qualified hardware for the Mars 2020 Rover (Perseverance), and led a research team in the development of a new aluminum-based fuel for a lander that may one day go to Europa, one of Jupiter’s icy moons. Now at MIT, Peter’s research explores new ways of extracting energy from aluminum waste to power electricity generation and seawater desalination in the aftermath of natural disasters, and in general he is interested in developing technologies that help solve problems that contribute to or are caused by climate change. In addition to his research, Peter is an instructor for one of the capstone mechanical engineering design classes at MIT, and he also teaches thermodynamics to high school seniors from underrepresented and underserved communities through MIT’s Office of Engineering Outreach Programs. Beyond academia, Peter is also an avid jazz pianist and composer and has traveled the world using music as a bridge to both educate and learn from communities impacted by the climate crisis.
Application-Driven Requirements for Lithium-Ion Batteries
Dr. Aziz Abdellahi
Principal Scientist, A123 Systems LLC
Striving for compliance with international CO2 emissions targets, the global automotive fleet is trending towards decarbonization through the rapid electrification of transport. This will be achieved not only through the increased adoption of high voltage electrified vehicles (EVs and PHEVs), but also through the pairing of 48V battery packs with increasingly efficient internal combustion engine (ICE) designs implemented in mild hybrid electric vehicles (MHEVs).
Battery packs for EVs and MHEVs both rely on lithium ion (Li-ion) battery technology and often use similar battery chemistries, but due to the varying pack function in the vehicle, the cell operating conditions (and therefore performance requirements) are radically different. In other words, a similarly sized and driven vehicle will impose different demands on the battery pack depending on the electrification topology.
In this talk, we will map how different pack function (e.g. regenerative braking, start/stop, electronic accessories, electric boost and propulsion) translates to pack sizing, operating temperature, mean and peak C-rate, and state-of-charge swing. Implications on testing and evaluation of battery life will be discussed, with special attention devoted to the importance of designing and interpreting application-relevant cell-level cycling tests.
Aziz Abdellahi works as a Principal Scientist at A123 Systems, a world leader in energy storage for automotive and grid applications. Aziz is currently leading A123’s Advanced Simulation team, whose mission is to support the design of next-generation Li-ion batteries using multi-scale modeling. His expertise includes atomistic modeling, electrochemical modeling, equivalent circuit modeling, battery life modeling, statistical pack analysis and vehicle-level modeling. Aziz holds a PhD in Materials Engineering from the Massachusetts Institute of Technology (Ceder group) and has authored 14 peer- reviewed publications in the field of Li-ion batteries. He was the recipient of the “Norman Hackerman Young Author Award” (Electrochemical Society, 2014), and the recipient of SAE’s “Outstanding Oral Presentation Award” (Society of Automotive Engineers, 2018).
Single-Electron Currents in Designer Single-Cluster Devices
Suman Gunasekaran, Columbia Chemistry PhD Student
Atomically precise clusters can be used to create single-electron devices wherein a single redox-active cluster is connected to two macroscopic electrodes via anchoring ligands. Unlike single-electron devices comprising nanocrystals, these cluster-based devices can be fabricated with atomic precision. This affords an unprecedented level of control over the device properties. Herein, we design a series of cobalt chalcogenide clusters with varying ligand geometries and core nuclearities to control their current–voltage (I–V) characteristics in a scanning tunneling microscope-based break junction (STM-BJ) device. First, the device geometry is modified by precisely positioning junction-anchoring ligands on the surface of the cluster. We show that the I–V characteristics are independent of ligand placement, confirming a sequential, single-electron tunneling mechanism. Next, we chemically fuse two clusters to realize a larger cluster dimer that behaves as a single electronic unit, possessing a smaller reorganization energy and more accessible redox states than the monomeric analogues. As a result, dimer-based devices exhibit significantly higher currents and can even be pushed to current saturation at high bias. Owing to these controllable properties, single-cluster junctions serve as an excellent platform for exploring incoherent charge transport processes at the nanoscale. With this understanding, as well as properties such as nonlinear I–V characteristics and rectification, these molecular clusters may function as conductive inorganic nodes in new devices and materials.
Interfacial Transport of Li+ Dictates Coulombic Efficiency and Deposition Morphology in Rechargeable Li Metal Anodes
Richard May, Columbia Chemical Engineering PhD Student
Although Li metal batteries offer the highest possible specific energy density, practical application is plagued by Li filament growth that lowers Coulombic efficiency (CE) and leads to serious safety concerns. Li ion transport through the complex, heterogeneous solid electrolyte interphase (SEI) on Li metal is hypothesized to play a key role in Li deposition and dissolution morphologies, yet current characterization techniques (e.g., cryogenic electron microscopy, surface science methods) cannot capture dynamics at the electrode/electrolyte interface. Here, we use one- and two-dimensional 7Li exchange spectroscopy (EXSY) nuclear magnetic resonance (NMR) to quantitively assess Li ion transport at electrode/SEI/electrolyte interfaces on Li metal anodes after electrochemical cycling in ether-based solvents. Assignment of individual compounds in the SEI is enabled by 1H®7Li and 19F®7Li cross polarization and facilitates a description of Li ion transport across discrete interfaces within the SEI that otherwise suffer from poor spectral resolution in 7Li NMR. In contrast to conventional wisdom on how the SEI facilitates smooth Li deposits, NMR and X-ray photoelectron spectroscopy (XPS) show that the addition of LiNO3 to LiTFSI leads to a thicker, more heterogeneous (i.e., containing more diverse chemical compounds) SEI that is correlated with substantially higher CE and lower surface area Li deposits compared to LiTFSI alone. Instead, NMR indicates that solubility and ionic conductivity of the SEI are critical to controlling Li deposition behavior in ether-based electrolytes.
Hybrid Catalytic Systems for Sustainable CO2 Reduction to Value-Added Oxygenates
Neal Biswas, Columbia Chemical Engineering PhD Student
Measures must be taken to reduce atmospheric CO2 concentrations and mitigate the effects of climate change. This presentation introduces three different hybrid catalytic strategies for CO2 conversion into value-added oxygenates. First, a two-stage system is described where CO2 is electrocatalytically reduced into syngas followed by the thermocatalytic methanol synthesis. The work here focuses on the electrochemical CO2 reduction reaction to produce syngas with tunable CO/H2 ratios. Using a combination of experimental measurements and density functional theory calculations, palladium modified niobium nitride (Pd/NbN) is found to generate much higher CO and H2 partial current densities than Pd/VN and commercial Pd/C catalysts, while also reducing the precious metal loading. Second, another two-stage system is proposed where CO2 is electrocatalytically reduced into ethylene and syngas followed by thermocatalytic hydroformylation into C3 oxygenates. Oxide-derived copper and silver electrocatalysts are able to tune the C2H4/CO/H2 product ratio, however a vapor-fed CO2 flow cell must be used to overcome CO2 mass transfer limitations and eventually be integrated with the thermocatalytic hydroformylation step. Third, a hybrid plasma-catalysis system is described where CO2 and ethane are directly converted into oxygenates in a one-step process under ambient conditions. In plasma-only experiments, lower plasma powers are found to promote oxygenate selectivity while higher powers favor reactant dissociation into CO and methane. The addition of catalysts inside and outside of the plasma discharge zone can also help stabilize reactive intermediates and further enhance oxygenate selectivity.
Framework for evaluating the performance limits of membraneless electrolyzers
Xueqi Pang, Columbia Chemical Engineering PhD Student
Emerging membraneless electrolyzers offer an attractive approach to lowering the cost of hydrogen (H2) production from water electrolysis thanks to potential advantages in durability and manufacturability that are made possible by elimination of membranes or diaphragms from the device architecture. However, a fair comparison of the performance limits of membraneless electrolyzers to conventional electrolyzers is hindered by the early stage of research and absence of established design rules for the former. This task is made all the more difficult by the need to quantitatively describe multiphase flow between the electrodes in membraneless electrolyzers, which can have a huge impact on gas product purity. Using a parallel plate membraneless electrolyzer (PPME) as a model system, this study takes a combined experimental and modeling approach to explore its performance limits and quantitatively describe the trade-offs between efficiency, current density, electrode size, and product purity. Central to this work is the use of in situ high-speed videography (HSV) to monitor the width of H2 bubble plumes produced downstream of parallel plate electrodes as a function of current density, electrode separation distance, and the Reynolds number (Re) associated with flowing 0.5 M H2SO4 electrolyte. These measurements reveal that the HSV-derived dimensionless bubble plume width serves as an excellent descriptor for correlating the aforementioned operating conditions with H2 crossover rates. These empirical relationships, combined with electrochemical engineering design principles, provide a valuable framework for exploring performance limits and guiding the design of optimized membraneless electrolyzers. Our analysis shows that the efficiencies and current densities of optimized PPMEs constrained to H2 crossover rates of 1% can exceed those of conventional alkaline electrolyzers but are lower than the efficiencies and current densities achieved by zero-gap polymer electrolyte membrane (PEM) electrolyzers.
Some Thoughts on Transport in and Design of Li-Ion Cathodes
Professor Alan West, Columbia Electrochemical Energy Center, Department of Chemical Engineering, Columbia University
Batteries are complex, with important phenomena arising from multiple length scales. Advances thus require multiscale experimental inquiries, and mathematical models, including multiscale models, may be employed to design, analyze and integrate studies. In early-stage research efforts, close collaboration with experimental efforts may result both in dramatically improved model fidelity and in more optimal utilization of experimental resources. We present approaches to augment physics-based models of Li-ion cathodes with statistical methodologies. Several examples are illustrated.
Alan West received his PhD in Chemical Engineering from the University of California and his BS from Case Western Reserve University. He is the co-director of the Columbia Electrochemical Energy Center and is the Samuel Ruben-Peter G. Viele Professor of Electrochemistry, with appointments in the Department of Chemical Engineering and the Department of Earth and Environmental Engineering. His research interests include batteries, electrochemical synthesis, and fuel cells.
Enabling Energy Dense Lithium Battery Anodes with Thin Film Electrolytes
Professor Wyatt Tenhaeff, Department of Chemical Engineering, University of Rochester
Lithium ion batteries (LIBs) are essential to modern daily life, powering smartphones, laptop/tablet computers, and increasingly electric vehicles. In the nearly 30 years since their commercial introduction, the graphite anode of LIBs has not substantially changed. Graphite reversibly hosts Li+ through intercalation/deintercalation and forms a stable solid-electrolyte interface through electrochemical reduction of the liquid electrolyte – critical to the reversible cycling of LIBs. However, graphite anodes possess a relatively low specific capacity (372 mAh g-1). Next-generation Si and Li metal anodes offer an order-of-magnitude enhancement in specific capacity but suffer from several fundamental challenges.
This presentation demonstrates how solid electrolyte thin films can be employed to address these challenges in Li metal and Si anodes, enabling next generation energy-dense batteries. For Li metal anodes, a solid electrolyte interfacial layer consisting of a lithium phosphorous oxynitride (Lipon) thin film electrolyte coupled to a gold-alloying interlayer was developed and shown to promote the electrodeposition of smooth, homogeneous, mirror-like Li metal morphologies. The effectiveness and integrity of the Lipon protective layer was assessed using in operando impedance spectroscopy and ex situ SEM/EDS characterization. Strategies to incorporate ultrathin layers of Lipon (~50 nm thick) into conventional lithium ion battery cell designs will also be discussed. A significant challenge with Si anodes is the >300% volume expansion, resulting in unstable passivation of the electrode surface. Conformal nanoscale polymer films were synthesized as artificial solid electrolyte interface (SEI) layers for Si using initiated chemical vapor deposition (iCVD). Ultrathin films on the order of 25 nm thick were shown to improve specific capacity retention, coulombic efficiency, and rate capability, which is attributed to a mediation of the electrolyte reduction processes. This presentation discusses the progress to date on these two critical anode materials and highlights outstanding questions and engineering challenges for the future.
Wyatt E. Tenhaeff is an Associate Professor in the Department of Chemical Engineering at the University of Rochester. He received a B.S. in Chemical Engineering from Oregon State University in 2004 and Ph.D. in Chemical Engineering from the Massachusetts Institute of Technology in 2009, specializing in vapor deposition of polymer thin films. Following his Ph.D., Dr. Tenhaeff received a Weinberg Fellowship at Oak Ridge National Laboratory, joining the thin film battery group. Following the fellowship, he transitioned to a Staff Scientist position. Then in 2013, he began his academic career at the University of Rochester. His current research interests are energy storage, solid state lithium metal batteries, and thin film deposition technologies. He has received several recognitions including an R&D 100 award for his work on safe impact resistant electrolytes for lithium ion batteries, the Curtis Award for Nontenured Faculty Teaching at the University of Rochester, and the NSF CAREER award.
Friday, November 13, 2020 @ 12:00 pm
1/18/19: Prof. Byungha Shin, KAIST
1/25/19: Nick Brady/Jack Davis, Ph.D. Student at Columbia
2/15/19: Prof. Daniel Esposito, Solar Fuels Engineering Lab at Columbia
3/1/19: Jake Russell/Anna Dorfi, Ph.D. Student at Columbia
3/15/19: Alex Couzis, CCNY/Urban Electric Power
4/26/19: Jon Vardner/Steven Denny, Ph.D. Student at Columbia
5/10/19: Qian Cheng/Brian Tackett, Ph.D. Student at Columbia
9/20/19: Prof. Daniel Steingart, Co-Director of CEEC
9/27/19: Aykut Aksit, Ph.D. Student at Columbia
Rebecca Ciez, Princeton postdoctoral fellow
10/11/19: Dr. Nongnuch Artrith, Research Scientist at Columbia
10/25/19: Prof. Lauren Marbella, The Marbella Lab at Columbia
11/1/19: Emily Hsu, Ph.D. Student at Columbia
Dr. Amir Zangiabadi, Director of Electron Microscopy Labs, CNI
11/22/19: Prof. Bruce Usher, Director of Tamer Center at Columbia
12/6/19: Dr. Kathy Ayers, VP of R&D at Proton Onsite / Nel Hydrogen
1/17/20: Prof. Jin Suntivich, Cornell University
2/7/20: Prof. Yuan Yang, Yang Research Group at Columbia
2/14/20: Darren Hammell, Executive VP of Business Development, Princeton Power Systems, Visiting Fellow, Princeton University
4/10/20: Prof. Dan Steingart, Co-Director of CEEC
4/17/20: Jianzhou Qu, Ph.D. Student at Columbia
4/24/20: Wesley Chang, Ph.D. Student at Princeton University
5/1/20: Karthik Mayilvahanan, Ph.D. Student at Columbia
6/26/20: Rob Mohr, Ph.D. Student at Columbia
Sophie Lee, Ph.D. Student at Drexel University
7/10/20: Luis Rebollar, Ph.D. Student at Drexel University
Dr. Oliver Harris, Tang Lab at Drexel University