382 Hits in 0.94 sec

Python Battery Mathematical Modelling (PyBaMM)

Valentin Sulzer, Scott G. Marquis, Robert Timms, Martin Robinson, S. Jon Chapman
2021 Journal of Open Research Software  
Sulzer, Scott Marquis, Robert Timms, Martin Robinson, Ferran Brosa-Planella, Tom Tranter, Thibault Lestang, Diego Alonso Álvarez, Jacqueline Edge, Colin Please, Jon Chapman, Fergus Cooper, Felipe Salinas  ...  example notebooks) • matplotlib≥2.0 • jax=0.1.75, (not supported on Windows) • jaxlib==0.1.52, (not supported on Windows) Optional: • scikits.odes≥2.4.0 (optional DAE solver, requires SUNDIALS 5.0.0) Valentin  ... 
doi:10.5334/jors.309 fatcat:skunheadwrghnhc7nyd3npnlwa

An Algorithmic Safety VEST For Li-ion Batteries During Fast Charging [article]

Peyman Mohtat, Sravan Pannala, Valentin Sulzer, Jason B. Siegel, Anna G. Stefanopoulou
2021 arXiv   pre-print
Fast charging of lithium-ion batteries is crucial to increase desirability for consumers and hence accelerate the adoption of electric vehicles. A major barrier to shorter charge times is the accelerated aging of the battery at higher charging rates, which can be driven by lithium plating, increased solid electrolyte interphase growth due to elevated temperatures, and particle cracking due to mechanical stress. Lithium plating depends on the overpotential of the negative electrode, and
more » ... l stress depends on the concentration gradient, both of which cannot be measured directly. Techniques based on physics-based models of the battery and optimal control algorithms have been developed to this end. While these methods show promise in reducing degradation, their optimization algorithms' complexity can limit their implementation. In this paper, we present a method based on the constant current constant voltage (CC-CV) charging scheme, called CC-CVησT (VEST). The new approach is simpler to implement and can be used with any model to impose varying levels of constraints on variables pertinent to degradation, such as plating potential and mechanical stress. We demonstrate the new CC-CVησT charging using an electrochemical model with mechanical and thermal effects included. Furthermore, we discuss how uncertainties can be accounted for by considering safety margins for the plating and stress constraints.
arXiv:2108.07833v1 fatcat:42jldstqefh4ppge7sjgvc72qi

Promise and Challenges of a Data-Driven Approach for Battery Lifetime Prognostics [article]

Valentin Sulzer, Peyman Mohtat, Suhak Lee, Jason B. Siegel, Anna G. Stefanopoulou
2020 arXiv   pre-print
Recent data-driven approaches have shown great potential in early prediction of battery cycle life by utilizing features from the discharge voltage curve. However, these studies caution that data-driven approaches must be combined with specific design of experiments in order to limit the range of aging conditions, since the expected life of Li-ion batteries is a complex function of various aging factors. In this work, we investigate the performance of the data-driven approach for battery
more » ... e prognostics with Li-ion batteries cycled under a variety of aging conditions, in order to determine when the data-driven approach can successfully be applied. Results show a correlation between the variance of the discharge capacity difference and the end-of-life for cells aged under a wide range of charge/discharge C-rates and operating temperatures. This holds despite the different conditions being used not only to cycle the batteries but also to obtain the features: the features are calculated directly from cycling data without separate slow characterization cycles at a controlled temperature. However, the correlation weakens considerably when the voltage data window for feature extraction is reduced, or when features from the charge voltage curve instead of discharge are used. As deep constant-current discharges rarely happen in practice, this imposes new challenges for applying this method in a real-world system.
arXiv:2010.07460v1 fatcat:ni7eosgmwjf3vlhv45nmkvu32i

Faster Lead-Acid Battery Simulations from Porous-Electrode Theory: II. Asymptotic Analysis [article]

Valentin Sulzer, S. Jon Chapman, Colin P. Please, David A. Howey, Charles W. Monroe
2019 arXiv   pre-print
Electrochemical and equivalent-circuit modelling are the two most popular approaches to battery simulation, but the former is computationally expensive and the latter provides limited physical insight. A theoretical middle ground would be useful to support battery management, on-line diagnostics, and cell design. We analyse a thermodynamically consistent, isothermal porous-electrode model of a discharging lead-acid battery. Asymptotic analysis of this full model produces three reduced-order
more » ... ls, which relate the electrical behaviour to microscopic material properties, but simulate discharge at speeds approaching an equivalent circuit. A lumped-parameter model, which neglects spatial property variations, proves accurate for C-rates below 0.1C, while a spatially resolved higher-order solution retains accuracy up to 5C. The problem of parameter estimation is addressed by fitting experimental data with the reduced-order models.
arXiv:1902.01774v1 fatcat:uoswbead6fdtfdo7fh32h4mtgm

Faster Lead-Acid Battery Simulations from Porous-Electrode Theory: I. Physical Model [article]

Valentin Sulzer, S. Jon Chapman, Colin P. Please, David A. Howey, Charles W. Monroe
2019 arXiv   pre-print
An isothermal porous-electrode model of a discharging lead-acid battery is presented, which includes an extension of concentrated-solution theory that accounts for excluded-volume effects, local pressure variation, and a detailed microscopic water balance. The approach accounts for three typically neglected physical phenomena: convection, pressure diffusion, and variation of liquid volume with state of charge. Rescaling of the governing equations uncovers a set of fundamental dimensionless
more » ... eters that control the battery's response. Total volume change during discharge and nonuniform pressure prove to be higher-order effects in cells where variations occur in just one spatial dimension. A numerical solution is developed and exploited to predict transient cell voltages and internal concentration profiles in response to a range of C-rates. The dependence of discharge capacity on C-rate deviates substantially from Peukert's simple power law: charge capacity is concentration-limited at low C-rates, and voltage-limited at high C-rates. The model is fit to experimental data, showing good agreement.
arXiv:1902.01771v1 fatcat:vjli7nmhdngurnc23vankkjxlu

A Suite of Reduced-Order Models of a Single-Layer Lithium-ion Pouch Cell [article]

Scott G. Marquis, Robert Timms, Valentin Sulzer, Colin P. Please, S. Jon Chapman
2020 arXiv   pre-print
For many practical applications, fully coupled three-dimensional models describing the behaviour of lithium-ion pouch cells are too computationally expensive. However, owing to the small aspect ratio of typical pouch cell designs, such models are well approximated by splitting the problem into a model for through-cell behaviour and a model for the transverse behaviour. In this paper, we combine different simplifications to through-cell and transverse models to develop a hierarchy of
more » ... r pouch cell models. We give a critical numerical comparison of each of these models in both isothermal and thermal settings, and also study their performance on realistic drive cycle data. Finally, we make recommendations regarding model selection, taking into account the available computational resource and the quantities of interest in a particular study.
arXiv:2008.03691v1 fatcat:efqiaqkhxzho5ckbic3xbnbob4

An asymptotic derivation of a single particle model with electrolyte [article]

Scott G. Marquis, Valentin Sulzer, Robert Timms, Colin P. Please, S. Jon Chapman
2019 arXiv   pre-print
The standard continuum model of a lithium-ion battery, the Doyle-Fuller-Newman (DFN) model, is computationally expensive to solve. Typically simpler models, such as the single particle model (SPM), are used to provide insight for control purposes. Recently, there has been a move to extend the SPM to include electrolyte effects, which increase the accuracy and range of applicability. However, these extended models are derived in an ad-hoc manner, which leaves open the possibility that important
more » ... erms may have been neglected, resulting in the model not being as accurate as possible. In this paper, we provide a systematic asymptotic derivation of both the SPM and a correction term that accounts for the behaviour in the electrolyte. Firstly, this allows us to quantify the error in the reduced model in terms of ratios of key parameters in the model, from which the range of applicable operating conditions can be determined. Secondly, in comparing our model with the ad-hoc models from the literature, we show that previous models have neglected a key set of terms. In particular, we make the crucial distinction between writing the terminal voltage in pointwise and electrode-averaged form, which allows us to gain additional accuracy whilst maintaining the same computational complexity as the existing models.
arXiv:1905.12553v2 fatcat:pvou2yqox5bg3kwhmizg4nradu

Asymptotic Reduction of a Lithium-Ion Pouch Cell Model

Robert Timms, Scott G. Marquis, Valentin Sulzer, Colin P. Please, S. Jonathan Chapman
2021 SIAM Journal on Applied Mathematics  
Redistribution subject to SIAM license or copyright; see TIMMS, MARQUIS, SULZER, PLEASE, AND CHAPMAN 3.1.1. Charge conservation in the solids.  ... 
doi:10.1137/20m1336898 fatcat:kxohpnvga5cjdg3fhiatd5eala

NeuralPDE: Automating Physics-Informed Neural Networks (PINNs) with Error Approximations [article]

Kirill Zubov, Zoe McCarthy, Yingbo Ma, Francesco Calisto, Valerio Pagliarino, Simone Azeglio, Luca Bottero, Emmanuel Luján, Valentin Sulzer, Ashutosh Bharambe, Nand Vinchhi, Kaushik Balakrishnan (+2 others)
2021 arXiv   pre-print
Physics-informed neural networks (PINNs) are an increasingly powerful way to solve partial differential equations, generate digital twins, and create neural surrogates of physical models. In this manuscript we detail the inner workings of NeuralPDE.jl and show how a formulation structured around numerical quadrature gives rise to new loss functions which allow for adaptivity towards bounded error tolerances. We describe the various ways one can use the tool, detailing mathematical techniques
more » ... e using extended loss functions for parameter estimation and operator discovery, to help potential users adopt these PINN-based techniques into their workflow. We showcase how NeuralPDE uses a purely symbolic formulation so that all of the underlying training code is generated from an abstract formulation, and show how to make use of GPUs and solve systems of PDEs. Afterwards we give a detailed performance analysis which showcases the trade-off between training techniques on a large set of PDEs. We end by focusing on a complex multiphysics example, the Doyle-Fuller-Newman (DFN) Model, and showcase how this PDE can be formulated and solved with NeuralPDE. Together this manuscript is meant to be a detailed and approachable technical report to help potential users of the technique quickly get a sense of the real-world performance trade-offs and use cases of the PINN techniques.
arXiv:2107.09443v1 fatcat:22zfxicti5ed3msl6lcbzmynga

Lithium-ion battery degradation: how to model it

Simon O'Kane, Weilong Ai, Ganesh Madabattula, Diego Alonso-Albarez, Robert Timms, Valentin Sulzer, Jacqueline Sophie Edge, Billy Wu, Gregory J. Offer, Monica Marinescu
2022 Physical Chemistry, Chemical Physics - PCCP  
Robert Timms and Valentin Sulzer added the constant voltage charge protocol and event state feature to PyBaMM and also provided technical support with PyBaMM.  ... 
doi:10.1039/d2cp00417h pmid:35311847 fatcat:atpqm2b57fdv3diyd2yigadfei

Lithium-ion battery degradation: how to model it [article]

Simon E. J. O'Kane, Weilong Ai, Ganesh Madabattula, Diego Alonso Alvarez, Robert Timms, Valentin Sulzer, Jacqueline Sophie Edge, Billy Wu, Gregory J. Offer, Monica Marinescu
2022 arXiv   pre-print
Robert Timms and Valentin Sulzer added the constant voltage charge protocol and event state feature to PyBaMM and also provided technical support with PyBaMM.  ... 
arXiv:2112.02037v2 fatcat:6ey7txuw5zawhdwa6gq7ep5bii

liionpack: A Python package for simulating packs of batteries with PyBaMM

Thomas Tranter, Robert Timms, Valentin Sulzer, Ferran Planella, Gavin Wiggins, Suryanarayana Karra, Priyanshu Agarwal, Saransh Chopra, Srikanth Allu, Paul Shearing, Dan Brett
2022 Journal of Open Source Software  
The API for liionpack was designed to provide a simple and efficient extension to the PyBaMM (Sulzer et al., 2021) framework allowing users to scale up simulations from single cells to many thousands  ... 
doi:10.21105/joss.04051 fatcat:xup4mz3lyfgj7hjwuwdt547n2i

Faster Lead-Acid Battery Simulations from Porous-Electrode Theory: Part I. Physical Model

Valentin Sulzer, S. Jon Chapman, Colin P. Please, David A. Howey, Charles W. Monroe
2019 Journal of the Electrochemical Society  
ORCID Valentin Sulzer S. Jon Chapman Colin P. Please David A.  ... 
doi:10.1149/2.0301910jes fatcat:5yu52lnabzfltjzrwyr4musctm

Review—"Knees" in Lithium-Ion Battery Aging Trajectories

Peter M Attia, Alexander Allen Bills, Ferran Brosa Planella, Philipp Dechent, Goncalo dos Reis, Matthieu Dubarry, Paul Gasper, Richard Gilchrist, Samuel Greenbank, David Howey, Ouyang LIU, Edwin Khoo (+5 others)
2022 Journal of the Electrochemical Society  
Note that LAM ne and LAM pe do not directly correspond to LAM of lithiated or delithiated electrode sites; see Sulzer et al. 93 for more information.  ...  Sulzer et al. 93 replicated a similar mechanism in Figure 11 by simulating continuous constantcurrent discharge and constant-current, constant-voltage charge of a single particle model with SEI formation  ... 
doi:10.1149/1945-7111/ac6d13 fatcat:fs6paadlhvgqzfgxwxn2wdjd5y

Probing heterogeneity in Li-ion batteries with coupled multiscale models of electrochemistry and thermal transport using tomographic domains

Thomas George Tranter, Robert Timms, Thomas Heenan, Scott Marquis, Valentin Sulzer, Anmol Jnawali, Matthew D. R. Kok, Colin Peter Please, S Jon Chapman, Paul R. Shearing, Dan Brett
2020 Journal of the Electrochemical Society  
This work presents a methodology for coupling two open-source modelling frameworks in a highly parallel fashion across multiple length scales to solve an electrical current and heat transport problem for commercial cylindrical lithium-ion batteries. The global current and heat transfer problems are formulated as resistor networks and solved using a finite difference method on a network extracted from an X-ray tomogram of an MJ1 18650 battery. The electrochemistry governing the heat generation
more » ... solved at the local level using a physically parameterized model. Electrochemical models are solved for different regions of a spirally wound cylindrical cell in parallel, coupled via charge conservation at the current collectors in a "battery of batteries" fashion, similar to the concept of modelling a pack. Thermal connections between layers in the spiral winding are established and heat transport is solved globally in a two-dimensional fashion, allowing for the subsequent extension to three dimensions. Great heterogeneity in local current density is predicted by the model which is also found to have some temperature dependence with ramifications for battery degradation.
doi:10.1149/1945-7111/aba44b fatcat:2cdq7vcwircdhmgb4tz57qmkxi
« Previous Showing results 1 — 15 out of 382 results