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Motivated by recent work on AC electro-osmosis, a general theory of ``induced-charge electro-osmosis'' (ICEO) has been developed, and a variety of new microfluidic pumping and mixing strategies have been proposed using... more
Motivated by recent work on AC electro-osmosis, a general theory of ``induced-charge electro-osmosis'' (ICEO) has been developed, and a variety of new microfluidic pumping and mixing strategies have been proposed using weak DC and AC applied voltages [physics/0304090, physics/0306100]. ICEO slip of a liquid electrolyte generally occurs at polarizable (metal or dielectric) surfaces in response to applied electric fields. Due
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Growth of the solid electrolyte interphase (SEI) is a major driver of capacity fade in LIBs. Despite its importance, the fundamental mechanisms remain unclear, primarily because of the complicated reaction pathways involved[1–3]. SEI... more
Growth of the solid electrolyte interphase (SEI) is a major driver of capacity fade in LIBs. Despite its importance, the fundamental mechanisms remain unclear, primarily because of the complicated reaction pathways involved[1–3]. SEI growth can be both electrochemical and chemical in nature[4], and thus, it is a strong function of the potential and degree of lithiation of the electrode. We model the early-stage and long-term growth of SEI by accurately capturing the potential dependence of its formation kinetics as well as long term rate limiting steps, and validating it against the world’s largest open source battery cycling data, generated in-house[5]. This is done using the Multiphase Porous Electrode Theory (MPET) framework[6] on graphite (phase separating) and carbon black (non phase separating) particles. Lithium plating is another key degradation phenomenon that has been elusive, and it becomes important while trying to fast-charge batteries, i.e., 0% - 80% state-of-charge in 30 mins. We show that lithium plating is a key function of electrode morphology, phase-separation dynamics and potential. Phase-separation in graphite is modeled in the electrode using the Cahn-Hilliard Reaction framework described by Bazant[7]. We understand the electrochemistry of the onset of lithium plating with in-situ measurements connected to real time cell potential in a phase-separating electrode for the first time[8]. Results indicate that the peak SEI-forming currents are higher for higher driving currents. Also, we find that SEI only grows during electrode lithiation, i.e. the battery only degrades while being charged. We also find that onset of lithium plating is correctly captured only when phase separation in active material is accounted for. Further, the onset of plating is delayed on electrodes with a thick SEI layer – understanding SEI/plating coupling is integral to predicting fast charging manufacturing protocols for LIBs. This work holds promise for the predictive design of procedures[9] for manufacture and formation of LIBs. [1] Cohen, Y. S.; Cohen, Y.; Aurbach, D. Micromorphological Studies of Lithium Electrodes in Alkyl Carbonate Solutions Using in Situ Atomic Force Microscopy. J. Phys. Chem. B 2000, 104, 12282–12291. https://doi.org/10.1021/jp002526b. [2] Horstmann, B.; Single, F.; Latz, A. Review on Multi-Scale Models of Solid-Electrolyte Interphase Formation, Current Opinion in Electrochemistry 13, 62-69 2019. [3] Nie, M.; Abraham, D. P.; Seo, D. M.; Chen, Y.; Bose, A.; Lucht, B. L. Role of Solution Structure in Solid Electrolyte Interphase Formation on Graphite with LiPF6 in Propylene Carbonate. J. Phys. Chem. C 2013, 117 (48), 25381–25389, https://doi.org/10.1021/jp409765w. [4] Das, S.; Attia, P. M.; Chueh, W. C.; Bazant, M. Z. Electrochemical Kinetics of SEI Growth on Carbon Black: Part II. Modeling. J. Electrochem. Soc. 2019, 166 (4), E107– E118. https://doi.org/10.1149/2.0241904jes. [5] Attia, P. M.; Das, S.; Harris, S. J.; Bazant, M. Z.; Chueh, W. C. Electrochemical Kinetics of SEI Growth on Carbon Black: Part I. Experiments. J. Electrochem. Soc. 2019, 166 (4), E97–E106. https://doi.org/10.1149/2.0231904jes. [6] Smith, R. B.; Bazant, M. Z. Multiphase Porous Electrode Theory, J. Electrochem. Soc. 2017, 164 (11). https://doi.org/10.1149/2.0171711jes. [7] Bazant, M. Z., Theory of chemical kinetics and charge transfer based on nonequilibrium thermodynamics, Accounts of Chemical Research, 46(5), 1144–1160. https://doi.org/10.1021/ar300145c [8] T. Gao, Y. Han, S. Das, T. Zhou, D. Fraggedakis, N. Nadkarni, C. N. Yeh, W. Chueh, J. Li, M.Z. Bazant, Interplay of lithium intercalation and plating on graphite using in-situ optical measurements, submitted. [9] Huang, W.; Attia, P. M.; Wang, H.; Renfrew, S. E.; Jin, N.; Das, S.; Zhang, Z.; Boyle, D. T.; Li, Y.; Bazant, M. Z.; McCloskey, B. D.; Chueh, W. C. and Cui, Y.; Nano Letters 2019 19 (8), 5140-5148. DOI: 10.1021/acs.nanolett.9b01515
Research Interests: Materials Science, Electrochemistry, Kinetics, Graphite, Ion, and 2 moreAnode and Meeting Abstracts(Anode and Meeting Abstracts)
(Anode and Meeting Abstracts)
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This talk will describe the physics of driven nucleation and growth in battery materials. The resulting nonequilibrium pattern formation may be either reaction-limited or transport limited. Examples of the former include driven phase... more
This talk will describe the physics of driven nucleation and growth in battery materials. The resulting nonequilibrium pattern formation may be either reaction-limited or transport limited. Examples of the former include driven phase separation in Li-ion batteries, electrodeposition in Li-air batteries, and Li plating in Li-ion batteries, controlled by electro-autocatalysis and competing electrochemical reactions. Examples of the latter include stable electrodeposition in Li-metal batteries with charged porous separators, controlled by deionization shock waves.
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Potential safety hazard of lithium ion batteries, their long recharging time and performance degradation during usage are the major obstacles that prevent the wide adoption of electric vehicles in our society. Lithium plating on graphite... more
Potential safety hazard of lithium ion batteries, their long recharging time and performance degradation during usage are the major obstacles that prevent the wide adoption of electric vehicles in our society. Lithium plating on graphite anode is considered the leading cause of thermal runaway, degradation and the barrier for fast charging. However, the onset of lithium plating on graphite anodes is not well understood. For the first time, we resolved the spatial dynamics of lithiation of a single graphite particle using in-situ optical microscopy, and shed light on the interplay between lithium intercalation and plating. Enabled by simultaneously monitoring of the voltage, phase transformation and lithium plating, we are able to elucidate the energetics and kinetics of the two competing reactions, and establish a comprehensive mechanistic picture of Li plating mechanism on graphite anode. The proposed mechanism was further validated by simulation using a 1-D phase field model. This work is therefore providing insights on guidelines of designing graphite anode and operating LiB for reducing the risk of lithium plating.
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Growth of the solid electrolyte interphase (SEI) is a major driver of capacity fade in LIBs. Despite its importance, the fundamental mechanisms remain unclear, primarily because of the complicated reaction pathways involved [1–3]. SEI... more
Growth of the solid electrolyte interphase (SEI) is a major driver of capacity fade in LIBs. Despite its importance, the fundamental mechanisms remain unclear, primarily because of the complicated reaction pathways involved [1–3]. SEI growth can be both electrochemical and chemical in nature [4,5], and thus, it is a strong function of the potential and degree of lithiation of the electrode. We model the early-stage and long-term growth of SEI by accurately capturing the potential dependence of its formation kinetics as well as long term rate limiting steps. Battery degradation involves a complex interplay of multiple phenomena, most of which are unknown. Our model captures some of the essential trends that we see while cycling hundreds of commercial cells [6]. This is done using the Multiphase Porous Electrode Theory (MPET) framework [7] on graphite (phase separating) and carbon black (non phase separating) particles. Lithium plating is another key degradation phenomenon that has been elusive, and it becomes important while trying to fast-charge batteries, i.e., 0% - 80% state-of-charge in 30 mins. We show that lithium plating is a key function of electrode morphology, phase-separation dynamics and potential. Phase-separation in graphite is modeled in the electrode using the Cahn-Hilliard Reaction framework described by Bazant [8]. We understand the electrochemistry of the onset of lithium plating with in-situ measurements connected to real time cell potential in a phase-separating electrode [9]. Results indicate that the peak SEI-forming currents are higher for higher driving currents and that SEI only grows during electrode lithiation, i.e. the battery only degrades while being charged. Additionally we capture a transition in the time-dependence of capacity fade from a steep initial drop to a more gradual ‘square-root-of-time’ trend by modeling the SEI as a bilayer with different rate-limiting steps for each type of SEI. We also find that onset of lithium plating is correctly captured only when phase separation in active material is accounted for. Further, the onset of plating is delayed on electrodes with a thick SEI layer – understanding SEI/plating coupling is integral to predicting fast charging manufacturing protocols for LIBs. This work holds promise for the predictive design of procedures [10] for manufacture and formation of LIBs. [1] Cohen, Y. S.; Cohen, Y.; Aurbach, D. Micromorphological Studies of Lithium Electrodes in Alkyl Carbonate Solutions Using in Situ Atomic Force Microscopy. J. Phys. Chem. B 2000, 104, 12282–12291. https://doi.org/10.1021/jp002526b. [2] Horstmann, B.; Single, F.; Latz, A. Review on Multi-Scale Models of Solid-Electrolyte Interphase Formation, Current Opinion in Electrochemistry 13, 62-69 2019. [3] Nie, M.; Abraham, D. P.; Seo, D. M.; Chen, Y.; Bose, A.; Lucht, B. L. Role of Solution Structure in Solid Electrolyte Interphase Formation on Graphite with LiPF6 in Propylene Carbonate. J. Phys. Chem. C 2013, 117 (48), 25381–25389, https://doi.org/10.1021/jp409765w. [4] Das, S.; Attia, P. M.; Chueh, W. C.; Bazant, M. Z. Electrochemical Kinetics of SEI Growth on Carbon Black: Part II. Modeling. J. Electrochem. Soc. 2019, 166 (4), E107– E118. https://doi.org/10.1149/2.0241904jes. [5] Attia, P. M.; Das, S.; Harris, S. J.; Bazant, M. Z.; Chueh, W. C. Electrochemical Kinetics of SEI Growth on Carbon Black: Part I. Experiments. J. Electrochem. Soc. 2019, 166 (4), E97–E106. https://doi.org/10.1149/2.0231904jes. [6] Severson, K. A., Attia, P. M., Jin, N., Perkins, N., Jiang, B., Yang, Z., ... & Bazant, M. Z. (2019). Data-driven prediction of battery cycle life before capacity degradation. Nature Energy, 4(5), 383-391. [7] Smith, R. B.; Bazant, M. Z. Multiphase Porous Electrode Theory, J. Electrochem. Soc. 2017, 164 (11). https://doi.org/10.1149/2.0171711jes. [8] Bazant, M. Z., Theory of chemical kinetics and charge transfer based on nonequilibrium thermodynamics, Accounts of Chemical Research, 46(5), 1144–1160. https://doi.org/10.1021/ar300145c [9] T. Gao, Y. Han, S. Das, T. Zhou, D. Fraggedakis, N. Nadkarni, C. N. Yeh, W. Chueh, J. Li, M.Z. Bazant, Interplay of lithium intercalation and plating on graphite using in-situ optical measurements, submitted. [10] Huang, W.; Attia, P. M.; Wang, H.; Renfrew, S. E.; Jin, N.; Das, S.; Zhang, Z.; Boyle, D. T.; Li, Y.; Bazant, M. Z.; McCloskey, B. D.; Chueh, W. C. and Cui, Y.; Nano Letters 2019 19 (8), 5140-5148. DOI: 10.1021/acs.nanolett.9b01515
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Research Interests: Physics, Materials Science, Electrochemistry, Nanoparticle, Lithium, and 14 moreNanoparticles, Chemical Physics, Medicine, Multidisciplinary, Computer Simulation, Nucleation, Phase transition, Electron Transport, Spinodal Decomposition, Phase Separation, Phosphates, Electrodes, Spinodal, and Cathode
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Research Interests: Engineering, Materials Science, Mechanics, Microfluidics, Medicine, and 14 moreNumerical Simulation, Microfabrication, Electrokinetics, Electrohydrodynamics, Physical sciences, Experimental Study, Electro-Osmosis, CHEMICAL SCIENCES, Voltage, Three Dimensional, Osmosis, Ionic Strength, Colloid, and Electrolyte
Research Interests: Engineering, Physics, Materials Science, Microfluidics, High Pressure, and 15 moreLab On A Chip, Fluid Dynamics, Medicine, Biomedical Research, DNA hybridization, CHEMICAL SCIENCES, Microchannel, Pressure, Distilled Water, Electrodes, Electroosmosis, Ionic Strength, Equipment Design, Lab on a chip Devices, and Proof of Concept
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The global devastation of the COVID-19 pandemic has led to calls for a revolution in heating, ventilation, and air conditioning (HVAC) systems to improve indoor air quality (IAQ), due to the dominant role of airborne transmission in... more
The global devastation of the COVID-19 pandemic has led to calls for a revolution in heating, ventilation, and air conditioning (HVAC) systems to improve indoor air quality (IAQ), due to the dominant role of airborne transmission in disease spread. While simple guidelines have recently been suggested to improve IAQ mainly by increasing ventilation and filtration, this goal must be achieved in an energy-efficient and economical manner and include all air cleaning mechanisms. Here, we develop a simple protocol to directly, quantitatively, and optimally control transmission risk while minimizing energy cost. We collect a large dataset of HVAC and IAQ measurements in buildings and show how models of infectious aerosol dynamics and HVAC operation can be combined with sensor data to predict transmission risk and energy consumption. Using this data, we also verify that a simple safety guideline is able to limit transmission risk in full data-driven simulations and thus may be used to guide...
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Reaction rates at spatially heterogeneous, unstable interfaces are notoriously difficult to quantify, yet are essential in engineering many chemical systems, such as batteries [1] and electro-catalysts [2]. Experimental characterizations... more
Reaction rates at spatially heterogeneous, unstable interfaces are notoriously difficult to quantify, yet are essential in engineering many chemical systems, such as batteries [1] and electro-catalysts [2]. Experimental characterizations of such materials by operando microscopy produce rich image datasets [3, 4, 5, 6], but data driven methods to learn physics from these images are still lacking due to the complex coupling of reaction kinetics, surface chemistry, and phase separation [7]. Here, we show that heterogeneous reaction kinetics can be learned from in-situ scanning transmission X-ray microscopy (STXM) images of carbon-coated lithium iron phosphate (LFP) nanoparticles. Combining a large dataset of STXM images with a thermodynamically consistent electrochemical phase-field model, PDE-constrained optimization, and uncertainty quantification, we extract the free energy landscape and reaction kinetics and verify their consistency with theoretical mod els. We also simultaneously ...
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A general theory of coupled ion–electron transfer (CIET) is presented, which unifies Marcus kinetics of electron transfer (ET) with Butler–Volmer kinetics of ion transfer (IT).
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Understanding the microscopic mechanism of Li-ion insertion in intercalation solids is crucial for the design of energy storage devices with optimal power and energy densities. Li intercalation kinetics has been traditionally treated by... more
Understanding the microscopic mechanism of Li-ion insertion in intercalation solids is crucial for the design of energy storage devices with optimal power and energy densities. Li intercalation kinetics has been traditionally treated by the phenomenological Butler-Volmer kinetics, but remains poorly measured and understood. For example, reported lithium intercalation kinetics for LiCoO2 in carbonate-electrolytes vary by 4-5 orders of magnitude. In this study, we developed experimental electrochemical methods for Li+-concentration-dependent Tafel kinetic measurements, and showed that the current of intercalation in LixCoO2 and NMCs was proportional to the fraction of empty Li+ sites. Exchange current densities and reorganization energies were also extracted for various electrode and electrolyte combinations. These results provide unique experimental evidence to support the microscopic mechanism of Li+ intercalation, where the electron and ion transfers are described by the theory of ...
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Disorder-driven degradation phenomena, such as structural phase transformations and surface reconstructions, can significantly reduce the lifetime of Li-ion batteries, especially those with nickel-rich layered-oxide cathodes. We develop a... more
Disorder-driven degradation phenomena, such as structural phase transformations and surface reconstructions, can significantly reduce the lifetime of Li-ion batteries, especially those with nickel-rich layered-oxide cathodes. We develop a general free energy model for layered-oxide ion-intercalation materials as a function of the degree of disorder, which represents the density of defects in the host crystal. The model accounts for defect core energies, long-range dipolar electrostatic forces, and configurational entropy of the solid solution. In the case of nickel-rich oxides, we hypothesize that nickel with a high concentration of defects is driven into the bulk by electrostatic forces as oxidation reactions at the solid-electrolyte interface reduce nickel and either evolve oxygen or oxidize the organic electrolyte at high potentials (>4.4 V vs Li/Li+). The model is used in battery cycling simulations to describe the extent of cathode degradation when using different voltage cu...
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Water-based anti-corrosion coatings, which are environmentally-friendly replacements for organic solvent-based coatings, do not perform well enough for use in the most challenging corrosion environments. The high water absorption capacity... more
Water-based anti-corrosion coatings, which are environmentally-friendly replacements for organic solvent-based coatings, do not perform well enough for use in the most challenging corrosion environments. The high water absorption capacity of water-based latex films may reduce barrier performance by contributing to corrosive reactant/product transport. We seek to understand the coupled effects of water absorption and ion transport in hydrated latex films, and to propose mechanisms explaining these effects. Water absorption and ion transport in films immersed in deionized (DI) water were monitored by mass gain and electrical conductivity measurements, respectively. Despite very similar polymer compositions between films, large differences in water absorption and ion transport rates were observed and explained by percolating networks at latex particle boundaries which facilitate transport. A semi-continuum model with three-component diffusion and convection-like elastic relaxation supp...
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Submitted for the DFD17 Meeting of The American Physical Society Salinity effects during immiscible displacement in porous media: electrokinetic stabilization of viscous fingering MOHAMMAD MIRZADEH, MARTIN BAZANT, MIT— Interfacial... more
Submitted for the DFD17 Meeting of The American Physical Society Salinity effects during immiscible displacement in porous media: electrokinetic stabilization of viscous fingering MOHAMMAD MIRZADEH, MARTIN BAZANT, MIT— Interfacial instabilities are ubiquitous in Fluid Mechanics and have been one of the main the subjects of pattern formation. However, these instabilities could lead to inefficiencies which are undesired in many applications. For instance, viscous fingering results in residual trapping of oil during secondary recovery when a low-viscosity fluid, e.g. water, is used for injection. In their seminal work, Saffman and Taylor showed that the onset of this instability is controlled by the viscosity ratio of the two fluids. However, other physiochemical processes could enhance or suppress viscous fingering. Here we consider the role of salinity effects on the front stability. Our recent theory suggests that viscous fingering could be controlled, and even suppressed, by approp...
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It has been established that combinations of increased ventilation, improved filtration, and other HVAC techniques can reduce the likelihood of airborne disease transmission in buildings. However, with only qualitative guidance, it is... more
It has been established that combinations of increased ventilation, improved filtration, and other HVAC techniques can reduce the likelihood of airborne disease transmission in buildings. However, with only qualitative guidance, it is difficult for building managers to make informed decisions. Furthermore, the possible actions almost always require additional energy consumption, which is generally not well characterized. To address this knowledge gap, we propose simplified physics-based models that can be used to quantify both the expected transmission rate and the associated energy consumption that result from HVAC system operation. By formulating all disinfection mechanisms in terms of "equivalent outdoor air", a common basis is established for comparing and combining different strategies. The transmission rate can thus be modeled by considering the airborne concentration of infectious particles that would result from an infector in the space. Energy consumption is then ...
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Soft colloidal particles with multiple surface patches of differing composition are critical to the development of complex macroscopic structures that can serve as interfacial catalysts, macroscale surfactants, electronically responsive... more
Soft colloidal particles with multiple surface patches of differing composition are critical to the development of complex macroscopic structures that can serve as interfacial catalysts, macroscale surfactants, electronically responsive materials, and drug delivery vehicles. Here, we present a continuous process for the scalable formation of soft colloidal particles with multiple surface domains that employs well-established principles of polymer precipitation and phase separation to controllably shape particle architectures. Our results illustrate the broad range of particle morphologies, including Janus and Cerberus structures, and surface compositions accessible to our versatile solution-based assembly system. We also identify polymer diffusion, precipitation, and vitrification as the primary determinants of particle structure for the first time.
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A zinc–iron redox-flow battery is developed that uses low cost redox materials and delivers high cell performance, consequently achieving an unprecedentedly low system capital cost under $100 per kW h.