bluuebunny/crossref_metadata_2025 huggingface dataset:
Titration Techniques for the Determination of Surface Species on Cathode Active Materials
Authors: Schuer Annika Regitta , Kuenzel Matthias , Yang Shuo , Mueller Franziska , Kosfeld Malte , Passerini Stefano , Bresser Dominic
Published: September 2023

Lithium ion batteries (LIBs) are the most important energy storage technology of our time. The number of LIBs has been constantly growing during the last years as well as the range of applications where LIBs are used, increasing the need for high energy density LIBs.

One of the main cathode materials for high energy density LIBs is Ni-rich LiNi0.8Co0.1Mn0.1O2 (NCM811).1 Unfortunately, due to the high Ni content this material is extremely sensitive towards water which poses a particular challenge for more sustainable aqueous processing. Contact with even traces of moisture from the air causes immediate formation of surface species such as LiOH and Li2CO3.2,3 The presence of these surface species not only leads to Li leaching from the structure and subsequent capacity loss but also facilitates side reactions with the electrolyte resulting in gas evolution and ultimately early failure of the battery.4

Developing reliable methods for the quantification of these harmful surface species can provide a link between the amount of surface species and the detrimental impact on the cell performance. Here we employed different measurement techniques to quantify the amount of LiOH and Li2CO3 on the NCM811 material surface.5 Warder titration6 and Winkler titration7 are two methods that have been long known for the determination of hydroxides and carbonates. We optimized these techniques for the determination of very small quantities of surface carbonate or hydroxide by testing the sensitivity for small lab size quantities of material and removing the possibility of additional CO2 uptake through the air. Titration as a way to quantify the amount of LiOH and Li2CO3 is a valuable measurement technique that can help to predict performance issues of the battery and can serve as a tool for quality control of cathode active materials.

References

(1) Armand, M.; Axmann, P.; Bresser, D.; Copley, M.; Edström, K.; Ekberg, C.; Guyomard, D.; Lestriez, B.; Novák, P.; Petranikova, M.; Porcher, W.; Trabesinger, S.; Wohlfahrt-Mehrens, M.; Zhang, H. J. Power Sources
2020, 479, 228708.

(2) Hofmann, M.; Kapuschinski, M.; Guntow, U.; Giffin, G. A. J. Electrochem. Soc.
2020,

(3) Jung, R.; Morasch, R.; Karayaylali, P.; Phillips, K.; Maglia, F.; Stinner, C.; Shao-Horn, Y.; Gasteiger, H. A. J. Electrochem. Soc.
2018, 165 (2), A132–A141.

(4) Kim, Y. J. Mater. Sci.
2013, 48 (24), 8547–8551.

(5) Schuer, A. R.; Kuenzel, M.; Yang, S.; Kosfeld, M.; Mueller, F.; Passerini, S.; Bresser, D. J. Power Sources
2022, 525 (231111).

(6) Benedetti-Pichler, A. A.; Cefola, M.; Waldman, B. Ind. Eng. Chem. - Anal. Ed.
1939, 11 (6), 327–332.

(7) Winkler, C. Praktische Übungen in Der Maßanalyse, 5. Auflage.; Verlag von A.Felix: Leipzig, 1920.
(John B. Goodenough Award of The Electrochemical Society) Oxide Revolution in Energy Storage
Authors: Manthiram Arumugam
Published: September 2023

Lithium-ion batteries have become an integral part of our daily life. The triumph of lithium-ion batteries is due to their much higher energy density compared to the other rechargeable battery systems. The high energy density along with superior cycling stability became possible because of the use of oxide cathodes in lithium-ion cells. There are only three families of cathodes for practical lithium-ion cells, and all the three of them are oxides: layered, spinel, and polyanion oxide cathodes.

As we move forward with vehicle electrification and renewable energy storage, multiple parameters, such as cost, energy density, power density, cycle life, safety, and environmental impact, need to be balanced. Among them, cost along with sustainability and supply chain issues is at the forefront. Cathode is the most expensive component in the cell. The oxide cathodes will still dominate the field, but with fierce efforts to reduce or eliminate less abundant and expensive metals in the cathode. This presentation will focus on eliminating the most expensive cobalt from layered oxide cathodes, then reducing the next expensive nickel in oxide cathodes, and finally replacing/eliminating lithium with sodium in oxide cathodes.

Reducing or eliminating cobalt in layered oxide cathodes by increasing the nickel content helps to increase the energy density and reduce the cost, but cathodes with high nickel contents are plagued with cycle, thermal, and air instabilities along with severe scale-up challenges. This presentation will focus on overcoming these challenges with controlled compositional and synthesis designs along with a profound understanding of the intricacies involved with the aid of advanced characterization methodologies. Particularly, issues, such as what different dopants really do, which dopant does what, and which is critical between surface reactivity and crack, in stabilizing high-nickel cathodes will be discussed. The dependence of surface reorganization/degradation pathways on electrolytes and the importance of electrolyte composition and high-voltage stability in stabilizing the cathode-electrolyte interphase will be presented with both graphite and lithium-metal anodes.

Finally, elimination of both cobalt and lithium while reducing the nickel content much further down will be described with sodium batteries based on layered oxide cathodes. Tailored electrolyte designs that provide long-life sodium cells with suppressed dendrites and enhanced safety will be presented.
(Invited) Operando Observation of Fast Charging in Li-Ion Cells
Authors: Du Zhijia , Wu Xianyang , LIU Jue
Published: September 2023

Fast charging (<15 min) of lithium-ion batteries (LIBs) for electrical vehicles (EVs) is widely seen as the key factor that will greatly stimulate the EV markets, and its realization is mainly hindered by the sluggish diffusion of Li+. To have a mechanistic understanding of Li+ diffusion within LIBs, in this study, structural evolutions of electrodes for a Ni-rich LiNi0.6Mn0.2Co0.2O2 (NMC622) || graphite cylindrical cell with high areal loading (2.78 mAh cm−2) are developed for operando neutron powder diffraction study at different charging rates. Via sequential Rietveld refinements, changes in structures of NMC622 and Li
x
C6 are obtained during moderate and fast charging (from 0.27 C to 4.4 C). NMC622 exhibits the same structural evolution regardless of C-rates. For phase transitions of Li
x
C6, the stage I (LiC6) phase emerges earlier during the stepwise intercalation at a lower state of charge when charging rate is increased. It is also found that the stage II (LiC12) → stage I (LiC6) transition is the rate-limiting step during fast charging. The LiC12 → LiC6 transition mechanism is further analyzed using the Johnson–Mehl–Avrami–Kolmogorov model. It is concluded as a diffusion-controlled, 1D phase transition with decreasing nucleation kinetics under increasing charging rates.
(Invited) Theoretical Analysis of Reaction Inhomogeneity and Lithium Plating Onset at Fast Charge Rates for Lithium Ion Batteries
Authors: Mijailovic Aleksandar S , Wang Guanyi , Yang Jian , Lu Wenquan , Wu Qingliu , Sheldon Brian W.
Published: September 2023

Inhomogeneous reactions in porous anodes may lead to lithium plating at high C-rates. Inhomogeneous lithium intercalation behavior in cathodes and anodes has been studied on particle and macroscale (i.e., cell) length scales. The effects of various physical and electrochemical phenomena (e.g., ionic transport, mass transport, interface reaction kinetics, and electrode thermodynamic behavior) have been studied in the context of reaction inhomogeneity. However, an accurate theoretical understanding of how these accelerate lithium metal plating has not been established in fast charging applications. Here, analytical and numerical modeling is used to develop a more complete understanding of how these coupled, nonlinear electrochemical and physical effects interplay to cause lithium plating. Specifically, it is shown that simple analytical solutions (which are functions of one or several nondimensional numbers) can with surprising accuracy approximate the onset of lithium plating predicted by calibrated numerical models of graphite half-cells. These analytical and numerical results are compared against in situ experimental observations of lithium plating onset during fast charging. This work attempts to use simplified analytical analysis to clarify and unify findings in more complex numerical models, which can ultimately provide strategies for mitigating Li metal plating during fast charging. Application of this theory for design and optimization of electrodes with engineered architectures is discussed.
Understanding the Effects of Uniform Stack Pressure in Extreme Fast Charging Lithium-Ion Batteries Via Operando X-Ray Diffraction
Authors: Allan-Cole Elizabeth , Garman Rachel , Hartin Sarah , Roberts Lacey , Narasimhan Swati , Toney Michael F
Published: September 2023

Enabling fast charging in lithium-ion batteries (LIBs) is critical for electric vehicle development, the U.S. goal being to charge to 80% of full capacity in 15 minutes [1]. This is a challenge due to significant capacity fade occurring at charge rates of 6C (charge in 60/6 = 10 minutes) and above. Fast charge rates induce irreversible lithium (Li) plating that adversely impacts battery performance and safety. External stack pressure can improve electrical contact and minimize delamination; further, an understanding of the impact of pressure on capacity fade can provide insight into the degradation mechanisms [2,3]. In this work, we investigate the extreme fast charging (XFC) regime, focusing on cell degradation and parasitic Li plating using single-layer pouch cells with graphite anodes, LiNi0.5Mn0.3Co0.2O2 (NMC532) cathodes, and 1.2 M LiPF6 in 3:7 weight % ethylene carbonate and diethyl carbonate (Gen2 electrolyte). To study the effect of pressure, electrode thickness and material capacity were varied. Cells were cycled under set uniform stack pressure configurations at 6C up to 140 times and tested between 10 – 150 psi. We have characterized fast charging cells under uniform pressure with spatially resolved operando X-ray diffraction (XRD) from high energy, high flux synchrotron radiation to study Li plating, parasitic reactions, and Li intercalation into graphite. Through spatially resolved operando XRD, we have mapped the intensity of LixC6 and Li metal peaks across the electrode to correlate peak intensity as a function of pressure and electrode thickness. This was complemented with ex situ X-ray photoelectron spectroscopy to study the composition of parasitic reaction products, corrosion and to correlate heterogeneity and local Li plating. Our results show an improvement in battery performance with increased uniform pressure. A reduction in Li plating was observed at elevated uniform pressures and Li plating appears more prevalent on the thicker electrodes. We believe that at increased pressure the reduced capacity fade arises from improved wettability, where the electrolyte acts as a lubricant increasing active sights, and a reduction in polarization across the thickness of the electrode leading to more homogenous reaction conditions. We emphasize the importance of electrode stack pressure in XFC batteries by quantifying the degradation mechanisms that cause capacity fade to enable better battery engineering.

References

USABC Goals – Lithium Electrode Based Cell and Manufacturing for Automotive Traction Applications, USABC (United States Advanced Battery Consortium), http://www.uscar.org/guest/article_view.php?articles_id=85

C. Cao et al. J. Electrochem. Soc. 129, 040540 (2022).

J. Cannarella and C. B. Arnold, J. Power Source, 245, 745-751 (2014).
High-Throughput Lithium Plating Quantification for Fast Charging Battery Design
Authors: Konz Zachary M. , Wirtz Brendan M. , Colclasure Andrew M. , Verma Ankit , Crafton Matthew J , Huang Tzu-Yang , McCloskey Bryan D.
Published: September 2023

Fast charging of most commercial lithium-ion batteries is limited due to fear of lithium plating on the graphite anode, which is difficult to detect and poses significant safety risk. Here we demonstrate the power of simple, accessible, and high-throughput cycling techniques to quantify irreversible Li plating spanning data from over 100 cells. We first demonstrate a protocol for Li|Graphite half-cells to observe the effects of energy density, charge rate, temperature, and State-of-Charge (SOC) on lithium plating and provide an interpretable empirical equation for predicting the plating onset SOC. We then design a method to quantify in-situ Li plating for commercially relevant Graphite|LiNi0.5Mn0.3Co0.2O2 (NMC) cells and compare with results from the experimentally convenient Li|Graphite configuration. Ex-situ mass spectrometry titration is used to validate the in-situ analysis methods. This work showcases innovative testing methods and data processing that enable rapid battery engineering.
Assessing the Impact of Thick Electrode Structure on the Fast Charge Performance of Lithium-Ion Batteries
Authors: Patel Prehit , Zhang Guangsheng , Nelson George J.
Published: September 2023

The lithium-ion battery (LIB) is a key technology for inexpensive, renewable, and safe energy storage system, but there are a few challenges that need to be addressed to make LIB more efficient. One critical challenge is increasing both energy density and fast charging capability. Increasing electrode thickness can increase the energy density of lithium-ion batteries. However, increasing electrode thickness increases transport limitations and the risk of lithium plating, which limit safe fast charging capability. This work analyzes prospective improvements to the conventional lithium-ion cell electrode structure that may facilitate high energy density and fast charging capabilities. A 2D lithium-ion battery model is applied to five different cell designs to understand the impact of thick electrode structure on performance at different charge and discharge rates for a single cell. These five different cell designs consist of one conventional cell and four cells with electrodes modified by varied electrolyte channel arrangements. The simulated electrodes were taken as Li(Ni1/3Mn1/3Co1/3)O2 (NMC) for the cathode and graphite for the anode. The simulated electrolyte was 1 M lithium hexafluorophosphate (LiPF6) in 1:1 ethylene carbonate (EC) and diethylene carbonate (DEC). All five cells were simulated under discharge at C/10, C/2 and 1C followed by charge at 1C, 3C, and 5C with no rest time prior to charge. Adding electrolyte channels on the anode side was found to facilitate lithium ion transport and reduce the risk of lithium plating. Modification of both electrodes did not present any benefit compared to the conventional cell. Analysis of cell behavior based on mass transport Fourier number and a dimensionless mass flux parameter was performed to compare different electrodes at different charge and discharge conditions. These dimensionless parameters provide a means for the general assessment of prospective electrode structure modifications.
(Digital Presentation) Mathematical Modeling of Thermal Events for Electrification Applications: Challenges and Opportunities
Authors: Zeng Yangbing , Yadav Anil , Lananna Scott , Garrick Taylor R.
Published: September 2023

In support of GM’s traction battery efforts, we have derived and implemented a method to link the heat generation due to chemical and electrochemical sources during a thermal event to the thermal runaway and thermal propagation of a battery module and a battery pack. Mathematical modeling of thermal runaway and propagation provides critical design insights and has become an important part of the electric vehicle (EV) development process. This talk covers multiple modeling methods with various levels of details to drive battery back and battery module design, as well as battery cell selection from a coarse to fine level. At a cell level, thermal runaway and propagation kinetics can be simulated and linked to characteristics of the battery cell design, from molecular, electrode, and jellyroll packaging level.

At the module, pack, and vehicle level, a Conjugated Heat Transfer (CHT) method alongside with the Computational Fluid Dynamics (CFD) can be used to describe flow and heat transfer conditions inside and outside of the vehicle. Integrating all of these analysis in the design and development process provides a powerful way to optimize key thermal runaway mitigation components for electric vehicles.
(Keynote) Learning Electrochemical Models from Images
Authors: Bazant Martin Z.
Published: September 2023

As illustrated by the work of Ralph White, traditional methods of electrochemical engineering are based on human intelligence: Mathematical models encoding physical hypotheses are proposed, tested against experimental data and refined by fitting adjustable parameters. Artificial intelligence is beginning to challenge this paradigm, since predictions can be made directly from data without the need for models, but such knowledge is often not transferrable to new situations. This talk will present a hybrid approach of solving PDE-constrained inverse problems to derive new multiscale models, in the context of Li-ion batteries. Examples include learning models of reaction kinetics and surface heterogeneities from x-ray adsorption images of phase separation in lithium iron phosphate nanoparticles [1], x-ray diffraction spectra for fictitious phase separation in nickel-rich oxide porous electrodes [2], and optical videos of lithium plating on graphite particles [3].

[1] H. Zhao, H. D. Deng, A. E. Cohen, J. Lim, Y. Li, D. Fraggedakis, B. Jiang, B. D. Storey, W. C. Chueh, R. D. Braatz, and M. Z. Bazant, Learning heterogeneous reaction kinetics from X-ray movies pixel-by-pixel, preprint, https://www.researchsquare.com/article/rs-2320040/v1

[2] J. Park, H. Zhao, S. D. Kang, K. Lim, C.-C. Chen, Y.-S. Yu, R. D. Braatz, D. A. Shapiro, J. Hong, M. F. Toney, M. Z. Bazant, and W. C. Chueh, Fictitious Phase Separation in Li Layered Oxides Driven by Electro-Autocatalysis, Nature Materials 20, 991-999 (2021).

[3] T. Gao, Y. Han, D. Fraggedakis, S. Das, T. Zhou, C.-N. Yeh, S. Xu, W. C. Chueh, J. Li, M. Z. Bazant, Interplay of lithium intercalation and plating on a single graphite particle, Joule 5, 1-22 (2021).
(Invited) Modeling Two-Phase Transport in the Cathode Catalyst Layer of a PEM Fuel Cell with a Focus on the Ionomer Phase Structure and Its Effect on Oxygen Transport
Authors: Nguyen Trung Van
Published: September 2023

A hydrophobic treatment was developed to reduce the liquid water saturation level and increase its removal rate from the cathode catalyst layer (CL) of a PEM fuel cell. If this was achieved, the transport rate of oxygen to the reactive sites would be expected to increase and the fuel cell performance would be improved, especially in the high current-density mass-transport controlled region. The performance of the fuel cells with the hydrophobically treated cathode CLs tested with humidified air at 70oC shows significant improvement (> 200% increase in peak power).[1,2] The polarization curves obtained show improvements over the entire curve from the kinetic-controlled region to the mass-transport affected and mass-transport limited regions instead of only the mass-transport limited region as originally expected. A mathematical model was developed to provide insight into the causes for the observed responses with a focus on the oxygen-water two-phase transport phenomena in the catalyst layer. It suggests the hydrophobic treatment affects the CL in two ways. First, the interface of the ionomer layer exposed to the gas pores becomes more hydrophobic and facilitates less coverage and faster water drainage from the CL resulting in better performance at high current densities. Second, it reduces the hydration level in the ionomer phase which results in higher oxygen concentration in the ionomer phase on top and in the catalyst agglomerates leading to higher performance over the whole polarization curve. This presentation will discuss the major features of the new model and the findings obtained in this study.[3] These efforts show that the modeling work is not just a simulation of the experimental results using established theories and equations. It requires researching, finding, and understanding the mechanisms and phenomena that govern the physical processes in the fuel cell and result in the measured fuel cell performance. The modeling work provides insights that could not be gained from fuel cell testing.

References

Regis P. Dowd Jr., Cynthia S. Day, and Trung Van Nguyen, “Engineering the Ionic Polymer Phase Surface Properties of a PEM Fuel Cell Catalyst Layer,” J. Electrochem. Soc., 164 (14), F138-F146 (2017). 10.1149/2.1081702jes

Regis P. Dowd, Yuanchao Li, and Trung Van Nguyen, “Controlling the Ionic Polymer/Gas Interface Property of a PEM Fuel Cell Catalyst Layer During Membrane Electrode Assembly Fabrication,” J. Appl. Electrochem., 50 (10) 993-1006 (2020). 10.1007/s10800-020-01453-w

Yuanchao Li and Trung Van Nguyen, “A One-Dimensional Model of the Cathode Catalyst Layer of a PEM Fuel cell Hydrophobically Treated for Water Management,” J. Electrochem. Soc., 169 114505 (2022). 10.1149/1945-7111/ac9bdf
(Keynote) Current Density Outliers in Batteries at Rest
Authors: Balsara Nitash P.
Published: September 2023

The need for creating safe electrolytes for lithium batteries is significant given the continued safety problems associated with current lithium-ion batteries. On the other hand, increasing electric vehicle (EV) adoption requires lithium-ion batteries that can be charged quickly. Some EV batteries have caught on fire despite neither being charged nor discharged. While the lithium that plates on graphite during fast charging affects battery safety, so do the internal ionic currents that occur when the battery is at rest after charging. These currents are difficult to quantify due to the absence of external current. We study a graphite electrode at rest after 6C fast charging using X-ray microtomography. We quantify spatially resolved current density distributions that originate at plated lithium and end in underlithiated graphite particles. The median current density at the plated lithium phase approaches zero in about 10 minutes after the battery current is stopped. Surprisingly, however, the range of current density was independent of time, with outliers above 20 mA cm-2. The persistence of outliers provides a clue as to the origin of catastrophic failure in batteries at rest. Some suggestions on how the outliers may be modeled using 3D Newman models will be discussed.
(Invited) The Importance of Modeling Interfacial Phenomena in Electrochemical Systems
Authors: Morey Madison , Cannon Andrew , Melsheimer Trevor , Ryan Emily
Published: September 2023

Chemical-physical processes at material interfaces drive performance and degradation in various energy and environmental systems, such as high energy density batteries, fuel cells, and electrolyzers. Transport (mass, charge, heat) to and through interfaces combined with reactions on the surface dictate the performance and also the degradation of these systems. To understand the fundamental material behavior of electrochemical systems, and to improve their performance and lifetime meso-scale interfacial modeling is needed that can resolve both the surface phenomena and the transport within the interfacial region. In this talk, I will discuss our research into computational modeling of interfacial and surface phenomena that drive performance in high energy density lithium batteries. Over multiple charge/discharge cycles non-uniform lithium plating and secondary reactions at the interface drive performance degradation and pose safety risks. The interplay between local transport, surface conditions, and operating conditions dictate these interfacial changes. In our work we use multi-phase, meso-scale modeling of the interfacial region to understand the driving forces for these changes and the coupling between physical phenomena to better understand the critical physics at the interface and to design more stable, long lasting interfaces.
(Keynote) Insight into Carbon Corrosion of Different Carbon Supports for Pt-Based Electrocatalysts for Polymer Electrolyte Fuel Cells from Interfacial Perspective
Authors: Zenyuk Iryna , Qi Yongzhen , Saha Prantik , Khedekar Kaustubh , Avid Arezoo , Huang Ying , Gao Ziliang , Chen Celine H. , Perego Andrea , Yildirim Hakan , Odgaard Madeleine , Asset Tristan , Atanassov Plamen
Published: September 2023

A mechanistic understanding of carbon corrosion in polymer electrolyte fuel cells (PEFCs) is required to design catalyst layers that are durable. Electrochemical oxidation of carbon occurs during uncontrolled startup and shutdown events of PEFCs leading to multitude of degradation events, including loss of electrochemical surface area (ECSA), pore structure collapse, Pt detachment, loss in ionomer and others. To understand carbon corrosion physics and resulting degradation mechanisms a detailed electrochemical characterization is needed to probe interfaces between Pt-ionomer, carbon-ionomer and to measure transport properties and the ECSA in the catalyst layer. In this presentation we will provide an overview of carbon corrosion understanding and our approaches to quantify the sequence of events. In these studies, PEFCs were subjected to the Department of Energy carbon corrosion accelerated stress test (AST) protocol. Various electrochemical techniques were used to describe interfaces and morphology, as well as transport properties for the cells at different stages of the AST. ECSA measurements, polarization curves, CO-displacement/stripping to determine sulfonic acid group coverage in dry and wet conditions, electrochemical impedance spectroscopy, oxygen transport resistance measurements and other techniques were used. In addition, physical characterization methods at the beginning of life (BOL) and end of life (EOL) were used, such as micro x-ray fluorescence mapping, focused ion beam scanning electron microscopy, transmission electron microscopy, x-ray photoelectron spectroscopy and Raman spectroscopy. A combination of electrochemical and physicochemical methods revealed that amorphous carbon oxidizes first, after which Pt detach resulting in the loss of the ECSA, followed by severe structure collapse, resulting in a poor oxygen transport resistance. We extend the study to carbon supports that are more graphitized to alleviate some of the issues observed with amorphous carbon support.
Leveraging Molecular Dynamics to Improve Porous Electrode Theory Modeling Predictions of Lithium-Ion Battery Cells
Authors: Dix Sean T. , Lowe Jeffrey S. , Rashvand Avei Mehdi , Garrick Taylor R.
Published: September 2023

Lithium-ion battery cell modeling using physics-based approaches such as porous electrode theory is a powerful tool for battery design and analysis. Performance metrics such as cell power and resistance can be quickly calculated in a pseudo-two-dimensional (P2D) framework and when coupled with thermal models, component level detail of heating and temperature rise can be evaluated1. For engineering of electric vehicle batteries, speed and fidelity of electrochemical models is paramount in a competitive landscape. Physics-based models allow for high fidelity but require detailed knowledge of the cell component material properties. Acquiring these material characteristics typically requires time-consuming and expensive experiments limiting the ability to quickly screen through cell designs. Therefore, engineering assumptions of the materials properties must be made based on prior tests or literature sources necessarily limiting model accuracy. One approach to improve model accuracy and circumvent costly experiments is to use atomistic modeling to calculate battery cell material properties such as kinetics, OCVs, and transport properties without the need of experiments2–4.

In this contribution we use molecular dynamics to calculate electrolyte conductivity and lithium-ion diffusion coefficients for a commercial electrolyte. We first validate our MD modeling approach by reproducing experimental measures of electrolyte conductivity for several test systems. We then construct a porous electrode theory model using the computed electrolyte transport values for the commercial system. Using this model, cell resistance and power is calculated and compared to experimental values measured from small-format pouch cells using the same electrolyte. We show how the variability in the MD modeling impacts cell performance metrics and demonstrate the robustness of this approach to improve cell-level model accuracy.

References:

(1) Song, M.; Hu, Y.; Choe, S.-Y.; Garrick, T. R. Analysis of the Heat Generation Rate of Lithium-Ion Battery Using an Electrochemical Thermal Model. J. Electrochem. Soc.
2020, 167 (12), 120503. https://doi.org/10.1149/1945-7111/aba96b.

(2) Liu, Z.; Li, Y.; Ji, Y.; Zhang, Q.; Xiao, X.; Yao, Y.; Chen, L.-Q.; Qi, Y. Dendrite-Free Lithium Based on Lessons Learned from Lithium and Magnesium Electrodeposition Morphology Simulations. Cell Rep. Phys. Sci.
2021, 2 (1), 100294. https://doi.org/10.1016/j.xcrp.2020.100294.

(3) Pande, V.; Viswanathan, V. Robust High-Fidelity DFT Study of the Lithium-Graphite Phase Diagram. Phys. Rev. Mater.
2018, 2 (12), 125401. https://doi.org/10.1103/PhysRevMaterials.2.125401.

(4) Wei, Y.; Zheng, J.; Cui, S.; Song, X.; Su, Y.; Deng, W.; Wu, Z.; Wang, X.; Wang, W.; Rao, M.; Lin, Y.; Wang, C.; Amine, K.; Pan, F. Kinetics Tuning of Li-Ion Diffusion in Layered Li(NixMnyCoz)O2. J. Am. Chem. Soc.
2015, 137 (26), 8364–8367. https://doi.org/10.1021/jacs.5b04040.

Figure 1
Modeling, Model Calibration, and Characterization of Graphite Anodes from Coal Derived Carbon
Authors: Paul Abigail , Magee Regan , Wichert Nathan , Wilczewski Warren , Mollah Rafid , Jones Matthew , Trembly Jason , Staser John A. , Garrick Taylor R.
Published: September 2023

Most current production electric vehicles (EVs) contain cells with a battery pack or module in order to maintain electrical conductivity, prevent fatigue due to vibrations, and provide efficient cooling. Various module hardware has to be designed in order to facilitate the efficient rejection of heat and contain volume change due to operation and battery cell aging. As we see a shift towards EVs both globally and domestically, the time from concept development to vehicle production needs to rapidly increase. The use of model-based engineering is critical to driving rapid design and virtual prototyping of electric vehicles to ensure that battery module components meet EV requirements.

Currently, empirical data is used to characterize and parameterize battery models that are used to drive design decisions at the battery cell and battery module level. Typical vehicle level use profiles such as the Hybrid Pulse Power Characterization (HPPC) profile, constant rate discharging, constant rate charging, and US06 drive cycles are traditionally used to parameterize battery models. In this work, we discuss select cell level testing profiles, evaluate the electrochemical transport and reaction parameters that are estimated using a porous electrode model, and provide insight and recommendations based on data from coal derived graphite for battery applications.
A Reduced Order Modeling Approach to Capture Transport within a Three-Electrode System Towards Fast Charge Applications
Authors: Mollah Rafid , Garrick Taylor R. , Gao Jing , Zeng Yangbing , Koch Brian
Published: September 2023

In support of GM's traction battery efforts, we derive and implement a reduced order modeling method to describe the electrochemical performance of a battery cell through the combination of a modified Newman Pseudo-2-Dimensional model and a three-electrode experimental apparatus. To assess the capability of the method, we compare the modeling results with experimental data for a lithiated graphite electrode and a lithiated nickel rich electrode system. The model is applied to simulate the electrochemical and transport processes within the battery cell to predict the negative electrode potential and positive electrode potential with respect to a lithium iron phosphate reference electrode, as well as the terminal voltage.

The manufacture and set up of the three electrode system, model development and reduction approaches, as well as a discussion of applicability to fast charge considerations to avoid lithium plating at the anode during a charging event will be presented.

References:

1. T. R. Garrick, J. Gao, X. Yang, and B. J. Koch. 2021. J. Electrochem. Soc. 168 010530

2. T. R. Garrick, J. Gao, X. Yang, and B. Koch. 2021, Meet. Abstr. MA2021-02 485

3. T. R. Garrick, J. Gao, and B. J. Koch. 2022. Meet. Abstr. MA2022-02 1077
Microstructure Model to Predict Mechanical Behavior of Lithium-Ion Battery Active Material Under Compressive Load
Authors: Teel Hunter , Lopata Joseph Steven , Garrick Taylor R. , Wang Fengkun , Zeng Yangbing , Shimpalee Sirivatch
Published: September 2023

A three-dimensional microstructure-based modeling method (3DMS) is developed to predict the mechanical behaviors of porous electrode that includes both active material (AM) and binders inside lithium-ion battery during compression. The geometry of both AM and binder shown in Fig. 1a is generated stochastically to create microstructures by using a modified MATBOX opensource program with our in-house code. The advanced technique of volume element generation is also established to overcome the interfacial error due to complexity of binder distribution as illustrated in Fig. 1b. The Finite Element Analysis (FEA) based solid-stress model is applied to predict local mechanical activities including stress-strain relationship and microstructure evolution.

The predictions of anisotropic behavior in the porous electrode under compressive loads will be presented and the insights into the microstructure deformation will be discussed. Further, the analysis results will be validated using experimental testing results acquired at various length scales. This work can be used for the model-based FEA platform to predict the impact of volume change under charge/discharge cycles, volume change of a jelly-roll during formation, and the response of the active material in typical pouch cells during battery module assembly.

Figure 1
Using Multiscale Direct Simulation Approach to Understanding Transports Behavior Inside PEM Water Electrolyzer
Authors: Sepe Mitchell , Lopata Joseph Steven , Madkour Sherif , Mayerhoefer Britta , Ciesielski Adrian , Shimpalee Sirivatch
Published: September 2023

In this work, numerical modeling techniques were developed to predict oxygen bubble evolution through complex pore geometries to provide information of gas transport pathways inside saturated porous transport layers (PTL). Each PTL undergoes an image processing technique that uses X-ray CT images to generate accurate 3D microstructures. An example of a generated PTL structure is shown in Figure 1.

Historically, meshing of the complex geometry was tedious and non-automated. Due to the random particle size across the geometry, a constant base size for meshing resulted in an inadequate mesh for accurate predictions. The Lattice-Boltzmann method is therefore more commonly used because a lattice is easier than a finite volume mesh to generate. Although sufficiently fine lattices adhered to the topology of the physical structure, simulations required a timestep between 1e-8 and 1e-10 seconds, resulting in long computational time.

Meshing techniques have improved and can now be applied to complex geometries. Using the finite volume method accompanied with an adaptive mesh and adaptive time scale, provides an accurate representation of the PTL structure and larger timesteps. A volume of fluid (VoF) method was used to model two phase flow, using liquid water and gaseous oxygen, through different PTL structures. Evolution, growth, size, velocity, and surface interaction of oxygen bubbles through microstructures were studied as also shown in Figure 2. Findings from the work will provide better understanding of oxygen evolution through saturated PTLs

Figure 1
Multiscale Modeling of Radio Frequency Reactor Coupled Catalyst Heating for Ethylene Production
Authors: Teel Hunter , Mercado Hector-Colon , Ganesan Prabhu , Craps Matthew , Gaillard Jay B , Ciesielski Peter , Shimpalee Sirivatch
Published: September 2023

Ethylene is the petrochemical compound with the highest production worldwide. Whether reactors are heated by direct fired heating or indirect heating via steam, manufacturers rely on economies of scale to overcome inherent thermodynamic inefficiencies while burning fossil fuels. New approaches to supply energy to chemical reactor systems can reduce energy waste created by traditional techniques while enabling large scale facilities to use other sources of raw materials and energy. Electromagnetic (EM) induction heating is one potential solution for providing energy efficiently to reactor systems. By taking advantage of the nature of radio frequency (RF) waves, heterogeneous-catalyst can be precisely targeted for heating inside the reactors. Site-selective heating can significantly reduce the energy requirements of the process by providing heat at reaction sites and reducing unnecessary heat transfer elsewhere. Other advantages to an EM enhanced system include rapid volumetric heating, broader turn-down capacity, and reduced process footprint.

The purpose of this work is to establish a multiscale computational fluid dynamics (CFD) model that can be used to emulate the proposed process mechanics at the macroscale and microscale. At the macroscale, coil geometry (coil diameter, gap between coils, distance between coil and susceptors) is investigated to elucidate coil design and effects on heating rates. In the microscale, the oxidative (CO2) dehydrogenation (ODH) of ethane is explored using different catalysts and possible catalyst/susceptor configurations with heat supplied by an EM susceptor. This multiscale method can also be applied to electrochemical systems.
Modeling and Simulation of a High Temperature Proton Exchange Membrane Fuel Cell
Authors: Aryal Utsav Raj , Zhu Gaohua , Banerjee Debasish
Published: September 2023

High temperature (HT) (around 120-200°C) PEM FCs are predicted to be the next generation of PEMFCs particularly for hydrogen-powered automobiles and combined heat and power (CHP) systems because the water management can be simplified at such temperatures as only a single phase of water vapor needs to be considered. Additionally, the cooling system can be streamlined due to an increase in temperature gradient between the coolant and the FC stack. This will also allow easy recovery of waste heat that can be used as a practical heat source. Furthermore, the CO tolerance improves dramatically at high temperatures thereby allowing HT PEMFCs to utilize reformed and impure hydrogen.

A single phase three-dimensional, steady-state, isothermal model for a single 5 HT PEM fuel cell with serpentine flow channels is implemented in COMSOL to investigate the effect of various operating conditions like temperature, back pressure and cathode flow rate and design parameters like catalyst layer loading, cathode GDL porosity, and flow field channels including parallel and interdigitated channels. Different performance indicators in terms of polarization curve, loss mechanisms, oxygen molar concentration, and anode and cathode pressure are represented for a complete overall analysis. In fact, the breakdown of different overpotential loss mechanism for HT PEMFC presented here is unique that not only quantifies these losses but also provides an accurate comparison with corresponding low temperature counterpart. The result from the computational model follows the experimental result very closely, thus, validating our model. The simulations stipulates that the performance of a HT PEMFC improves with increasing temperature, back pressure, and air flow rate. Increasing catalyst layer loading improves the performance up to a point after which it starts to drop at low voltages because of hindered gas diffusion. Similarly, a comparative study among different flow field channel is also presented indicating improved performance when going from parallel to interdigitated and serpentine channels. Furthermore, this study provides guidelines to optimize HT PEMFC performance through comprehensive parametric study.
In-Situ Analysis of Chronopotentiometry Data to Predict Electrodeposition Rates
Authors: St John Christopher , Arrington Christian L. , Oglesby Skyler , Gucik Mary Louise , Finnegan Patrick Sean , Weatherred Scott Edward , Carr Stephen M
Published: September 2023

Often in MEMS or NEMS microfabrication R&D, many single layer “test” samples are created prior to committing more complex multiple layer “device” samples which require more time and effort to create. Ideally, much of the R&D can focus on less critical test samples and the experimental results can then be applied to more valuable device wafers. We investigated tin electroforming into patterned polymer molds creating Meissner-Effect Transition-Edge-Sensor (ME-TES) devices1 and found multiple variables changed between the test and device samples making it difficult to target a desired tin metal thickness. These variables were analyzed and distilled down to two: (I) area and (II) the measured voltage at constant current 30 seconds after plating started. In addition to the underlying analysis, a Graphical User Interface (GUI)2 was developed in R to quickly calculate and predict in-situ tin electroplating rates regardless of uncontrolled variables in the sample.

ME-TES devices required a final tin plating feature height of 8-12 microns for 50-micron diameter discs coupled with patterned niobium electrical traces3. During chronopotentiometry experiments, two samples were plated for 1 minute and 18 minutes, respectively – both achieving the target height of 10 microns. This extreme variability in rate caused the height to undershoot or overshoot within just a few minutes of plating. Many variables were collected into a database and analyzed including wafer design layout, electrochemical methods, chemistry make-up, electrochemical setup, the use of a reference electrode, current density, voltage, mounting technique, height, device size, and surface roughness across the substrate. The resulting GUI resulted in fewer necessary test samples, reduced processing time, and improved accuracy in plating thickness.

(1) Finnegan, P. Packaging & Solid-state Materials and Fabrication Processes. In Packaging & Solid-state Materials and Fabrication Processes, June 2023.

(2) St. John, C. “R Shiny User Interface for Electrochemical Development.” In CoDA, Santa Fe NM, March 2023.

(3) Arrington, C.L. Optimizing Tin Electroplating for MEMS Meissner-Effect Transition Edge Sensors. In 243rd ECS Meeting with SOFC-XVIII, Boston, MA, 2023.

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.

SAND2022-10287A
The Use of Model-Predicted Internal States from Locally Linear, Gain-Scheduled, Reduced-Order Physics-Based Models in Model-Predictive Control Strategies
Authors: Evans Tyler A. P. , Vincent Tyrone , Kee Robert J.
Published: September 2023

The objective of the research is to develop reduced-order state-space models that can predict internal states that are not directly observable with existing sensors. In doing so, battery management systems (BMS) can make real-time control decisions based upon sensor inferences. For example, estimating local electrode Li and electrolyte Li-ion concentrations or local electrostatic potential differences between electrode and electrolyte phases offer valuable knowledge in predicting behaviors such as Li plating, dendrite growth, or electrode fracture. Such indirect predictive capabilities, for example, can enable fast-charging protocols that avoid damage mechanisms.

This talk explores the mathematical feasibility of estimating local Li concentrations and electrostatic potentials using observed current-voltage sequences. The approach for determining internal battery states begins with an estimator that uses observed input-output data from a physics-based reduced-order state-space model. If the model satisfies the property of observability, a sufficiently long window of input-output data can predict unique internal-state trajectories that are compatible with the observable data. The research considers understanding the effects of sampling time and state of charge on internal-state observability.

Efficient estimation algorithms must incorporate battery physics and chemistry yet be sufficiently simple as to run in real-time on a battery management system (BMS). The present research first develops a physics-based pseudo-two-dimensional (P2D) model, which describes battery thermodynamics, transport, and kinetics, results in a system of nonlinear, coupled, differential-algebraic equations that can be solved computationally, but too slow for real-time implementation. The P2D model is then reduced to a gain-scheduled, locally linear, state-space model that can be run in real-time. Both models are implemented within the MATLAB/Simulink framework that facilitates development and evaluation of control strategies.
On the Unique Parameterization of a Single Particle Model Using Electrochemical Impedance Spectroscopy (EIS) and Hybrid Power Pulse Characterization (HPPC) Tests
Authors: Olide Everardo , Pannala Sravan , Tran Vivian , Movavahedi Hamidreza , Siegel Jason , Stefanopoulou Anna
Published: September 2023

Prior work has shown that equivalent circuit models (ECM) fitted to match frequency data (EIS) do not necessarily match time data (HPPC). Depending on the fitting methodology, the quality of data, and the ECM order, the parameter mismatch is manageable and can be justified by the simplification of the physical phenomena in an ECM. An investigation of the fitting methods and the sensitivity to noise will be shown using synthetic data of an OCV-R2RC model.

The investigation will be expanded in fitting EIS and HPPC synthetic data from an SPMe and an SPM model. The sensitivity of the SPM parameters to the measured EIS and HPPC will clarify long-standing confusion of the uniqueness and even the magnitude of physically-relevant parameters in SPM models.

The learnings from the synthetic data will then be demonstrated with EIS and HPPC data obtained from several Graphite/NMC battery pouch cells at different states of charge (SOC) and states of health (SOH) after cycling at a variety of accelerated aging protocols that include c-rates, temperatures, SOC swing, and externally applied pressure.

Figure: Voltage Profile of Characterization Protocols(HPPC and EIS) for a single cell at different SOC.

Bottom right, Nyquist plot corresponding to first characterization scheme of a fresh and aged cell.

Figure 1