AutoLion™ FAQ

How do AutoLion™ simulation results compare with real experimental data?

We have put extra emphasis on ensuring that AutoLion™ simulation results can capture real behavior of Li-ion batteries over a wide range of operating conditions. For a wide range of Li-ion battery chemistries and designs, AutoLion™ simulations are found to be within 5% of measured data.

What are the differences between the AutoLion™ modeling approach as compared to Newman’s Dual Foil battery model?

Newman’s Dual Foil model was originally developed as an isothermal model (heat generation was solved and transport was not). This approach works to study the room temperature operation of small “coin cell” batteries. Later, various versions of this classic model were derived that have over-simplified treatment of thermal transport in Li-ion batteries. The AutoLion™ modeling framework is based on the accurate coupled treatment of heat and electrochemistry where electrochemical reactions cause heat generation in the battery and the temperature inside the battery in turn affects the reaction rate. This strong coupling-accurately captured in AutoLion™ has very little impact on room temperature performance simulation. However, under extreme temperature operations (such as large format cells with large surface area to volume ratio, and battery life modeling where temperature strongly influences the degradation rate) it becomes a major distinguishing feature for AutoLion™. In addition, the AutoLion™ modeling framework naturally enables safety simulations where the interaction of heat and battery reactions must be captured correctly.

I do not know much about battery electrochemistry. Can I still use AutoLion™? What will be my learning curve?

You do not need to be an expert in battery electrochemistry nor a veteran in engineering simulations to use AutoLion™. Even a user who has no idea what is inside a Li-ion battery will be able to use AutoLion™. There are various resources available to shorten the learning curve for AutoLion™, including 1) various example simulation files that users can download and work with to master various features, 2) software-in-use videos that users can follow to learn about how to use AutoLion™ to solve their pressing problems, 3) on-demand training videos that users can access to learn how to execute AutoLion™ at their own speed, 4) AutoLion™ tech support team which has extensive knowledge of Li-ion battery materials, modeling, and experimentation.

I don’t know the material properties that are needed as inputs to Li-ion battery software. How can I rely on AutoLion™ for my product development?

Without the knowledge of material properties that dictate performance, life and safety behavior of a Li-ion battery, users can’t rely on Li-ion battery simulation to solve their problems. To remove this key bottleneck stopping users from integrating Li-ion battery software in product development, we have measured material properties as a function of temperature and Li concentration for a wide variety of Li-ion battery chemistries. This material database comes standard with AutoLion™, and users can simply choose “database” values to reliably simulate their Li-ion batteries over a wide range of conditions. We have done various case studies to compare the results of AutoLion™ simulations with “database” properties with experiments and have found a good match. With AutoLion™, however, users are not bound to only use database values. AutoLion™ allows users to easily “extract” material parameters of their battery if they have access to standard experimental data.

Where do the default parameters for a new case file come from?

When a new case is created, the case will have preset values for all of the available inputs. While these values are representative of a typical commercial cell, they are not sourced from a specific model or manufacturer.

Can I input my own material into AutoLion™?

Yes. AutoLion™ allows you to simulate any material chemistry. Users can very easily incorporate any chemistry in AutoLion™ (if the chemistry of interest is not in our database already) and input its properties through user-defined functions (UDF) in AutoLion™. Users can easily input material properties as a function of temperature and Li concentration in the form of a function or a look up table. Adding a new material feature is not yet available in AutoLion-3D™.

Can I use mixed material electrodes for my simulation?

Users can choose multiple chemistries as mixture components for the cathode or anode of a Li-ion battery. The AutoLion™ user interface allows users to easily choose the mixture components, specify their weight fractions, and specify material properties such as particle radius and other electrochemical properties. Users are free to specify different properties for each mixture component. Currently, AutoLion-1D™ has mixed material simulation capability. This capability is under implementation for AutoLion-3D™.

Can I simulate behavior of a Li-ion battery under complex duty cycles with AutoLion-1D™?

AutoLion-1D™ provides users with the flexibility to simulate the behavior of a Li-ion battery under any duty cycle. Not only can users model battery behavior under constant current, constant power, and constant voltage conditions but they can also simulate any duty cycle (any combination of current, voltage, and power) through the user-defined load profile (UDLP) feature.

Can I run a parametric study on operating temperature and/or current?

Yes. AutoLion-1D™ offers the flexibility to run batch jobs where users can simulate Li-ion battery behavior over a wide range of temperatures and currents simultaneously.

What results can I generate using AutoLion-1D™?

AutoLion-1D™ allows users to simulate changes in cell voltage, current, and temperature with time. In addition, users can easily study cell internal behavior such as distribution of reaction current, Li concentration in electrolyte, Li concentration distribution in solid particles, etc. Transient internal distribution in cell thickness direction is available in output folders in .csv format. This can be imported easily into Microsoft Excel or other plotting softwares such as Techplot, Origin, Ensight, etc.

Can AutoLion-1D™ simulate calendar and cycle life for Li-ion batteries with different chemistries?

AutoLion-1D™ life modeling is based on an accurate mathematical representation of chemistry-specific degradation mechanisms. AutoLion-1D™ also enables users to simulate life of mixture chemistries. The current version of AutoLion-1D™ allows cycle life modeling under any cycling conditions and temperature.

Is AutoLion-3D™ supported on the Linux platform used by my organization?

Because the AutoLion-3D™ simulator works in conjunction with commercial CFD solvers, the most important requirement for the Linux OS is for it to be compatible with your CFD software (Fluent, Star-CCM+, etc.). In other words, the AutoLion-3D™ simulator will be compatible with any 64bit Linux platform which is supported by your CFD solver.

What types of meshes are compatible with AutoLion-3D™?

AutoLion-3D™ is highly flexible with mesh types. For pack models, any type of mesh (hexahedral, tetrahedral, etc.) can be used. For single cell model simulation, hexahedral mesh can be used. In addition to the flexibility of user generated meshes, AutoLion-3D™ also provides advanced automated mesh generation for a cell model if the user has Ansys ICEM installed. It can also generate complicated meshes with millions of cells in just a few minutes.

How does the AutoLion-3D™ pack model differ from the cell model?

In the pack model, temperature distribution in each cell is solved in three-dimensions but cell electrochemistry is solved only in the cell thickness direction. In the cell model, both electrochemistry and temperature are solved in true 3D space. This simplification for pack models allows more computational efficiency. We recommend the use of cell models when a user is interested in studying 3D effects of cell electrochemistry. The pack model is most efficient for other purposes such as safety simulation. Pack model allows for a substantially faster simulation time (useful for automotive scale pack simulations) while still retaining important features such as 3D thermal distribution.

Can I use AutoLion-3D™ to run parallel computations on my HPC cluster?

You can run AutoLion-3D™ parallel on HPC clusters if you purchase an AutoLion-3D™ parallel license.

What is MKL and how do I get it?

MKL stands for Math Kernel Library, which is an optimized math routines library developed by Intel®. AutoLion-3D™ uses functions from this library for fast computation. We recommend you use the specific version of Intel® MKL that is distributed along with the AutoLion-3D™ package. Other versions of MKL are currently not tested with AutoLion-3D™ and may cause issues. For more information on MKL, please go to this website.

I do not have ifort, the Intel® fortran compiler, installed on my Linux machine. Are there other compilers that are compatible with AutoLion-3D™?

GNU Fortran (a.k.a gfortran, which can be installed on any Linux platform) can be used if you don’t have Intel® Fortran installed. To use gfortran, go to libudf\usrsrc\build_libusr in the installation folder and replace ‘ifort’ with ‘gfortran’. It also should be noted that the Intel® Fortran compiler is free on Linux for non-commercial software development.

I do not have any 3D post-processing software. What can I use to view my simulation results?

CGNS files can be viewed by many commercial and open source post-processing softwares. For example, EnSight (download here) has a free version which can visualize CGNS data. Users are also free to use any other post-processing software which reads CGNS data.

Which types of data are output in the CGNS files for the single cell model?

The data types outputted in CGNS are Ce (electrolyte concentration), Cs (solid concentration), Phie (electrolyte potential), Phis (solid potential), SOC, Stoich, OCP, jrxn (reaction current density), temperature and qt (heat source).

I only have access to a 32-bit computer. Will I be able to run any AutoLion™ software on this computer?

No. AutoLion™ products are only compatible with 64-bit machines.