Stanford Energy Student Lectures 2023
Stanford students, postdocs, faculty, and staff were invited to our 13th annual summer series to learn about cutting-edge science and clean-energy breakthroughs from 16 students doing the research. A tutor from the School of Engineering's Technical Communication Program provided live feedback to each of the speakers on how to improve their presentations.
July 10th
Sang Cheol Kim
Title: High entropy electrolytes for practical lithium metal batteries
Abstract: Electrolyte engineering is crucial for improving battery performance, particularly for lithium metal batteries. Recent advances in electrolytes have greatly improved cyclability by enhancing electrochemical stability at the electrode interfaces, but concurrently achieving high ionic conductivity has remained challenging. Here we report an electrolyte design strategy for enhanced lithium metal batteries by increasing the molecular diversity in electrolytes, which essentially leads to high entropy electrolytes (HEEs). We find that the entropy effect reduces ion clustering while preserving the characteristic anion-rich solvation structures. Electrolytes with smaller-sized clusters exhibit a 2-fold improvement in ionic conductivity compared to conventional weakly-solvating electrolytes, enabling stable cycling at high current densities up to 2C in anode-free NMC622 || Cu pouch cells.
Bio: Sang Cheol Kim completed his undergraduate studies at Duke University, with degrees in Mechanical Engineering and Materials Science (MEMS) and Chemistry. After three years at LG Chem, designing and developing battery cells for electric vehicles, he moved to Stanford, where he received MS and PhD degrees in Materials Science and Engineering. During his graduate studies, Sang Cheol worked with Prof. Yi Cui to develop tools to probe the liquid electrolyte in batteries, and developed a new class of electrolytes called the high entropy electrolyte. Currently, Sang Cheol is a Stanford Energy Postdoctoral Fellow, working with Prof. Steven Chu on developing electrochemical solutions for energy and sustainability.
Xi Chen
Title: Evaluating and developing separation technologies for lithium-ion battery recycling
Abstract: The rising demand of sustainable energy significantly exceeds the current supply capacity, and recycling lithium-ion batteries (LIBs) is a critical step towards building a circular battery supply chain. Sustainable LIB batteries require efficient separation, while existing separation technologies suffer from high energy intensities and inadequate separation precision, and lack appreciation of the tradeoffs between water and energy consumption in industrial-scale operations. In this talk, I will present life-cycle analyses of water–energy impacts of industrial-scale lithium-ion battery (LIB) recycling, and development of membrane materials for high-purity lithium extraction. My work identifies that separation technologies play a critical role in reducing the environmental impacts of LIB recycling, and I employ the knowledge from my mechanistic studies to design membrane materials for selective extraction of lithium element from magnesium and sodium.
Bio: Dr. Xi Chen is currently a postdoctoral fellow in The Department of Chemical Engineering at Stanford University, working with Prof. William A. Tarpeh. He received his Ph.D. in Environmental Engineering at Columbia University in 2020. Dr. Chen focuses his research on advancing separation technologies for addressing global water-energy-environment challenges. His past studies include novel contributions toward 1) evaluating and developing technologies for recycling lithium-ion batteries, 2) management and treatment of high-salinity brines for clean water production, 3) energy conversion of low-temperature heat resources, and 4) advancing fundamental transport theory for polymer membranes. Dr. Chen holds a Master’s degree in Environmental Engineering from University of Illinois at Urbana-Champaign, and received his B.S. in Environmental Science from Nankai University in China.
July 17th
Renwen Yu
Title: Time-modulated near-field radiative heat transfer
Abstract: We explore near-field radiative heat transfer between two bodies under time modulation by developing a rigorous fluctuational electrodynamics formalism. We demonstrate that time modulation can results in the enhancement, suppression, elimination, or reversal of radiative heat flow between the two bodies, and can be used to create a radiative thermal diode with infinite contrast ratio, as well as a near-field radiative heat engine that pumps heat from the cold to the hot bodies. The formalism reveals a fundamental symmetry relation in the radiative heat transfer coefficients that underlies these effects. Our study indicates the significant capabilities of time modulation for managing nanoscale heat flow.
Bio: Renwen is a postdoctoral scholar in Professor Shanhui Fan’s group at Stanford. He does research in theoretical aspects of nanoscale thermal energy harvesting.
Briley Bourgeois
Title: Understanding photoreactions across multiple length scales – in situ ETEM and reactor-scale studies of plasmonic photochemistry
Abstract: Nanoscale metal structures can very strongly interact with light through a phenomenon called a plasmon resonance. These resonances collectively excite charge carriers in the structure which in turn can drive chemical reactions in unique ways. The behavior of these plasmonic photocatalysts is dictated by the nanoscale structure of the particles. As their size and shape changes, different atomic structures are exposed and the nature in which light is channeled by the particle is altered. These features, while much smaller than can be resolved by a traditional microscope, have a huge impact on the performance of plasmonic photocatalyst. In this work, we utilize in-situ transmission electron microscopy to control and study photochemistry with near-atomic resolution. We show that light can be used to control the presence of hydrogen within plasmonic catalysts and govern the most reactive sites on the catalyst’s surface. We further utilize bench-scale chemistry techniques to demonstrate improved chemical selectivity for hydrogenation chemistries for reactions driven by light instead of heat. With the ability to understand and build photocatalysts from fundamental length scales, better materials can be designed to drive important chemistries using sustainable energy source.
Bio: Currently, Briley is a 5th year PhD candidate in the Materials Science and Engineering department under the mentorship of Professor Jennifer Dionne. At Stanford, Briley studies plasmonic photochemistry using in-situ environmental and optically-coupled transmission electron microscopy in tandem with bench-scale catalytic measurements. Briley received his Bachelor’s degree in Engineering Physics from Tulane University in 2018. Under the guidance of Professors Matt Escarra and Doug Chrisey, Briley developed techniques for the scalable manufacturing of solar cell materials through high-power photochemical processing techniques.
July 24th
Mason Wu
Title: Stretchable, recyclable thermosets via photopolymerization and 3D printing of hemiacetal ester-based resins
Abstract: Achieving a circular plastics economy is one of our greatest environmental challenges, yet conventional mechanical recycling remains inadequate for thermoplastics and incompatible with thermosets. The next generation of plastic materials will be designed with the capacity for degradation and recycling at end-of-use. To address this opportunity in the burgeoning technologies of 3D printing and photolithography, we report a modular system for the production of degradable and recyclable thermosets via photopolymerization. The polyurethane backbone imparts robust, elastic, and tunable mechanical properties, while the use of hemiacetal ester linkages enables facile degradation under mild acid. The synthetic design allows for simple purification to regenerate a functional polyurethane diol.
Bio: Mason grew up in both Taipei and the Bay Area. He attended Cornell University for his undergraduate degree, where he began his research career in Professor Brett Fors’ group working on organic materials for organic light-emitting diodes and battery cathodes. Mason obtained his PhD in Chemistry at the Massachusetts Institute of Technology under the guidance of Professor Timothy Swager. At MIT, Mason’s research spanned a number of projects, including post-polymerization modification of polyoxazolines and porous bottlebrush polymers for gas separation membranes. Currently, Mason is a Taiwan Science and Technology Hub @Stanford Research Fellow in Professor Zhenan Bao’s group in the Department of Chemical Engineering. His research focuses on the design and synthesis of photopolymerizable and recyclable plastics.
Sonia Martin
Title: Electric vehicle green charging with marginal emissions signals
Abstract: Electric vehicles (EVs) are a promising clean transportation option, but they still release CO2 emissions when charging from the electricity grid. Often, EV drivers charge their vehicles when it is cheap or convenient, not when grid carbon intensity is lowest. Green charging, or smart charging control, is a solution to this problem that optimizes to reduce emissions by shifting electricity demand in between and across charging sessions. In this talk, I will present and validate a green charging control strategy based on actual EV driver data and historical grid emissions. The basis for this control is marginal emissions, or the emissions released when a new generator must be dispatched to the grid, which we find performs better than using average grid emissions data.
Bio: Sonia Martin is a 3rd year PhD candidate in the Stanford Sustainable Systems Lab. Her research centers around controlling battery systems to maximize their decarbonization potential. Specifically, she designs optimization algorithms for electric vehicles, electric buses, and aggregated stationary battery systems to ensure they are storing carbon-free power. Sonia obtained her M.S. from Stanford University in 2022 and B.S. from UC Berkeley in 2020, both in mechanical engineering.
July 31st
June Choi
Title: The fiscal impact of climate extremes and implications for the energy transition
Abstract: Currently, more than half of low-income countries accounting for more than 40% of the global poor are carrying unsustainable debt burdens. Many of these countries are exposed to intensifying climatic extremes, such as tropical cyclones (TC), which can be especially disruptive for smaller economies. The combination of these trends presents major challenges for these countries’ capacity to participate effectively in the energy transition. Understanding the channels by which extreme events influence the fiscal position of these countries is important for developing robust transition plans that ensure continued investment and progress towards both emissions reductions and adaptation goals. Here I present initial findings from my research investigating the fiscal impacts of tropical cyclones using an improved and exogenous measure of TC exposure.
Bio: June is a PhD candidate in Earth System Science co-advised by Profs. Noah Diffenbaugh and Marshall Burke. Her research focuses on equitable adaptation to extremes in a changing climate, motivated by her previous experience working in sustainable finance. She holds an MA in International Economics from Johns Hopkins SAIS and BA in Sociology and Asian Civilizations from Amherst College.
Zane Taylor
Title: Defect mechanisms and microstructure to 3D print metals for high temperature applications
Abstract: Refractory metals have some of the highest melting temperatures of elemental materials and are important to build components for extreme environments. Tantalum (Ta) is one such refractory metal best known for its bioactivity as biomedical implants, corrosion resistance, and resistance to radiation and high temperatures. The same properties that make Ta desirable for parts also makes it difficult to fabricate by traditional processes and by metal 3D printing techniques. Laser Powder Bed Fusion (LPBF) is one such 3D printing technique that has proven promising in overcoming the manufacturing challenges, allowing the creation of nearly arbitrary part geometries that were not previously accessible. However, challenges remain in controlling their unusual defect mechanisms and microstructures that control part performance. In this talk, I will present my initial experiments that are working to characterize LPBF of Ta in-situ to map out parameters controlling its structure-property relationships.
Bio: Zane Taylor is a PhD student in the Materials Science and Engineering Department at Stanford University. He works in the Dresselhaus-Marais group on metal additive manufacturing with a particular interest in the printing of refractory (high temperature) metals and in-situ/operando characterization techniques. He completed a B.S in Materials Science at the California Institute of Technology in 2022, where he researched polymer based additive manufacturing primarily with hydrogels.
August 7th
Jiawei Zhou
Title: Energy-efficient materials for the building envelope
Abstract: Energy efficiency is recognized as a key strategy to accelerate the transition to a clean energy society. In particular, the building sector contributes significantly to global greenhouse gas emissions, where space heating and cooling comprise a dominant fraction of the total energy consumption. Significant energy saving and emission reduction can be achieved if we can re-design the building thermal envelope. In this presentation, I will discuss materials engineering at the microstructural level for improving building energy efficiency. We will demonstrate an insulation structure that combines the insulation performance of vacuum insulation panels and the convenience of conventional foam insulations, i.e. can be cut, punctured or re-assembled. Such insulation materials can help to reduce the heating and cooling energy loads of the building and contribute to emission reduction.
Bio: Jiawei Zhou is currently a postdoc researcher working with Professor Yi Cui in the department of Materials Science and Engineering at Stanford University. He received his Ph.D degree in Mechanical Engineering at Massachusetts Institute of Technology in 2019. His work focuses on designing materials for improving energy efficiency broadly.
August 14th
Jiayi Li
Title: Organochalcogenide-halide perovskites
Abstract: Halide perovskites have risen as contenders for low-cost and efficient solar-cell absorbers. However, the composition that can deliver the desired efficiency and stability remains to be found. The moisture/thermal instability and light-induced halide segregation impede long-term stable optoelectronic properties. Therefore, we sought a different type of anion mixing, chalcogenide, to expand the accessible bandgaps of lead-halide perovskites. This talk presents a strategy to design and synthesize a novel family of 3D organochalcogenide-halide perovskites by using zwitterionic ligand. We systematically studied structural and electronic effects of chalcogenide. The highly desirable bandgaps, band dispersion, and improved stability of organochalcogenide-halide perovskites motivate the continued expansion and exploration of this new family of materials.
Bio: Jiayi Li received his B.S. in materials chemistry from Peking University in 2019. He is a fourth-year Chemistry Ph.D. candidate supported by the Stanford Interdisciplinary Graduate Fellowship (SIGF). His research in the Karunadasa Lab focuses on the fundamental properties and structural diversity of halide perovskites.
Josh Neutel
Title: Pathways to carbon neutrality in California
Abstract: California has ambitious plans for net-zero emissions by 2045, however, the road to carbon neutrality is not quite clear. The goal of this work is to evaluate various decarbonization technologies/policies, illuminating the most effective, economical, and feasible pathways to net-zero. To do so, an economy-wide model DECAL (DECarbonize CALifornia) was built using the Low Emissions Analysis Platform (LEAP). DECAL is a “bottom up” model with great depth and breadth, covering both the supply and demand side of the energy economy. The model is equipped with exogenously defined “levers” that control deployment rates, technology choice, and more. Hundreds of economy-wide decarbonization experiments were run, which helped clarify salient features of an otherwise uncertain transition. We find that no single technology can be used alone to reach California’s target; rather, a portfolio of solutions will be required. The electricity sector will require unprecedented infrastructure buildout to support added load, with solar, wind, batteries, natural gas with carbon capture and storage (CCS), and existing hydro and nuclear playing critical roles. Due to retirement lag-time, the transport sector will require aggressive sales rate targets to minimize 2045 vehicle emissions. CCS is an effective and affordable option in the industrial sector, whereas both heat pumps and resistance heating can play a role in the buildings sector. We identify refrigerants as a significant emissions source with sparse technical solutions. Bioenergy can help reduce near-term emissions across all sectors, but are ultimately limited by resource/feedstock constraints. Finally, true net-zero will be difficult to impossible without significant carbon dioxide removal. Key areas where innovation is needed include low global warming potential refrigerants, hydrogen delivery and storage, carbon capture and storage, and direct air capture.
Bio: Josh Neutel received his Bachelor’s in Chemical Engineering from the University of Southern California, as well as his Master’s in Environmental Engineering here at Stanford. He is currently a 2nd year PhD student at Stanford, advised by Sally Benson and Adam Brandt in Energy Resources Engineering, as well as Ram Rajagopal in Civil and Environmental Engineering. He is generally interested in data/computer science solutions for sustainability, as well as innovation and entrepreneurship. His focus the last two years has been on modeling California’s transition to net-zero emissions. His next project will be focused on creating data solutions to make Stanford’s commercial buildings more efficient.
August 21st
Dhruv Suri
Title: Watt’s the plan? Pathways to decarbonizing global electricity production through marginal abatement curves
Abstract: Globally, there is consensus that we need to rapidly decarbonize the production and supply of electricity, however, we do not have a roadmap that provides governments and key stakeholders with a pathway on which plants to decommission, where, and how. For every thermal power plant in the world, we evaluate the annual generation, operating costs, and carbon emissions, and estimate the expenditure required to abate emissions by transitioning the plant to solar, wind or other low-carbon fuel alternatives. We find that over a third of global emissions from thermal plants can be offset at zero or negative cost due to a unique combination of price of fuel input, utilization and available renewable resource potential, and that the entirety of the emissions from the thermal fleet can be displaced for a price of 200 $/ton of carbon dioxide.
Bio: Dhruv is a first year PhD student in energy science and engineering supervised by Ines Azevedo and a Knight Hennessy Scholar at Stanford. Before joining Stanford, Dhruv completed a bachelor's degree in aerospace engineering from the Manipal Institute of Technology in India and specialized in the design and fabrication of ducted wind turbines for the built environment. Dhruv also worked with IDinsight and the Rockefeller Foundation to scale the deployment of distributed energy systems in India, Africa, Myanmar and Puerto Rico. He’s the co-founder of an enterprise energy efficiency platform, BlueUrbn, that enables companies to scale energy efficiency and clean energy solutions in their building stock by developing net-zero roadmaps.
Yuelang Chen
Title: Fast-charging limitations of advanced electrolytes for lithium metal batteries
Abstract: Lithium metal batteries (LMBs) are being actively developed to meet the high-energy-density demand for electric vehicles (EVs). Fast charging is an important requirement for EV applications. While improving lithium metal Coulombic efficiency (CE) has been a focus for LMB electrolyte design, their performance under high current densities is less explored. Here, we evaluate the moderate-to-high-rate cycling stability of three recently developed advanced electrolytes, all of which are weakly solvating electrolytes with anion-derived solid electrolyte interfaces. All three electrolytes showed soft shorting behavior above various threshold current densities. Based on extensive characterizations, we propose a mechanism by which slow ion transport was the main factor that led to poor cycling stability due to concentration polarization, poor Li morphology, and closely packed residual solid electrolyte interphase (rSEI) structure. This work confirms the importance of fast ion transport for LMBs under moderate to fast charging conditions. Therefore, for electrolyte designs, improving CE must be accompanied by efficient ion transport in order to provide a viable solution to practical LMBs.
Bio: Yuelang Chen received his H.B.Sc. in Chemistry from the University of Toronto in 2019. He is currently a Ph.D. student working with Professor Zhenan Bao and Professor Yi Cui. His research focuses on the impact of electrolyte properties on the stability of lithium metal batteries.
Sara Ha
Title: Electrochemical modeling framework for lithium metal batteries
Abstract: Lithium metal batteries (LMB) with metallic lithium anodes promise high energy densities up to 500 Wh/kg that nearly doubles the energy density of current lithium-ion batteries. In this work, we develop an electrochemical model based on the well-known Newman-Doyle-Fuller (DFN) model by replacing the graphite with a lithium metal anode. The solid electrolyte interface (SEI) is included in the model which affects the stripping/plating kinetics on the lithium metal surface. The LMB model requires over 20 parameters to characterize the geometric, electrochemical, and kinetic properties. The parameters are mathematically identified using particle swarm optimization (PSO) and experimental cycling data. This model presents the opportunity to predict the behavior of real-world LMB batteries under various applied current such as the cell voltage response and internal states such as lithium-ion concentration in the electrolyte.
Bio: Sara is a 4th year PhD Candidate in Mechanical Engineering supervised by Prof. Simona Onori in the Energy Science and Engineering Department at Stanford University. She received her M.S. in Mechanical Engineering at Stanford University in 2019 and her B.S. in Mechanical Engineering at Georgia Institute of Technology in 2016.
August 28th
Emmanuel Balogun
Title: Equitable dynamic electricity pricing via implicitly constrained dual and subgradient methods
Abstract: Coordination of distributed energy resources is critical for electricity grid management. Although nodal pricing schemes can mitigate congestion and voltage deviations, the resulting prices are not necessarily equitable. In this work, we leverage market mechanisms for DER coordination and propose a daily dynamic nodal pricing scheme that incorporates equity. We introduce a pricing “oracle,” which we call the Power Distribution Authority, that sets equitable prices to manage the grid. We present two algorithms for executing this scheme and show that both methods can set prices that satisfy both grid voltage and equity constraints. The proposed algorithms also outperform the common utility time-of-use pricing schemes by at least 45%. New market mechanisms are needed as the grid is transforming, and power system operations can leverage these methods to develop pricing mechanisms in a grid-aware and equitable fashion.
Bio: Emmanuel Balogun is a PhD Candidate in Mechanical Engineering advised by Profs. Arun Majumdar, Simona Onori, and Ram Rajagopal. He attained his BSc. (Summa Cum Laude) in Mechanical Engineering in 2018 from Howard University, Washington DC. After his undergraduate studies and prior to joining Stanford, he helped shape the future of transportation at ChargePoint designing and developing future AC and DC fast charging products for Electric Vehicles and Fleets. His research is focused on computational methods for decarbonized, equitable energy systems, leveraging core expertise in Generative AI, Simulation, and Optimization.
Calvin Lin
Title: Electrified chemical reactors through inductive heating
Abstract: Fossil fuel heating is currently the primary method of producing high grade heat in the chemicals industry. To slash greenhouse gas emissions, electrified heating has become an optimistic, alternative pathway for process intensification. We propose a novel reactor that utilizes inductive heating to achieve volumetric heating profiles and higher efficiency in order to render higher conversion of feedstock compared to wall heating reactors. We apply this electrified heating system to two endothermic reactions: point source carbon capture and reverse water gas shift (RWGS) and validate its superior performance over conventional heating schemes. These results show promising extension to other thermochemical applications such as steam methane reforming, methane pyrolysis, and ethane steam cracking.
Bio: Calvin is a 2nd year Ph.D. student in electrical engineering in the Stanford University Power Electronics Research (SUPER) Lab under Professor Juan Rivas and the Fan Lab under Professor Jonathan Fan. He received his B.S. and M.S. in electrical engineering also at Stanford. In collaboration with the Fan Lab, his current research focuses on building high frequency power amplifiers for inductively heated chemical reactors. He also works with Australian National University to help build power electronics for inductively coupled plasma thrusters.
Jinwon Oh
Title:Catalytic materials for methane abatement and atmospheric methane removal
Abstract: Rapidly growing greenhouse gas concentrations have caused a continuous rise in global temperature. Therefore, ‘Negative-emission technologies’ (NETs), which not only prevent emissions but remove atmospheric greenhouse gases already present, will be necessary to halt the concerning warming trend going forward. NETs for CO2 have been studied intensely. However, negative emissions of other greenhouse gases-specifically CH4 - are relatively less studied. CH4 NETs are especially crucial because CH4 is more than 28 times as potent compared to CO2 at trapping heat in the atmosphere. Therefore, developing atmospheric CH4 removal technology can offer a new pathway to resolve the climate increase crisis. In this talk, I will present the feasibility of atmospheric methane removal using thermal catalytic oxidation. We synthesized catalysts with various materials and tested their activity and stability for low concentration methane oxidation. In particular, we found out that Pd-based catalysts show superior activity and stability for CH4 removal. We believe that the findings from this study would be a potential guideline for developing NETS of broader range of greenhouse gases.
Bio: Jinwon Oh is a 3rd year PhD candidate in the Department of Materials Science and Engineering supervised by Professor Matteo Cargnello in the Department of Chemical Engineering. He received his M.S. in Materials Science and Engineering at Korea Advanced Institute of Science and Technology (KAIST), and B.S. in Materials Science and Engineering at Korea University. His research focuses on nanocatalysts development for energy and environmental application.