AutoLion™ FAQ Posted on August 1, 2014October 26, 2015 by Rachel Shoemaker AutoLion™: General How does AutoLion™ simulation result compare with real experimental data? We have put extra emphasis in ensuring that AutoLion™ simulation result 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 in AutoLion™ modeling approach as compared to Newman’s Dual Foil battery model? Newman’s Dual Foil model was originally developed as an isothermal model (that is heat generation and transport was not solved). This is largely fine for 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. AutoLion™ modeling framework is based on accurate coupled treatment of heat and electrochemistry where electrochemical reaction causes 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 operation (very common for automotive applications)- especially for large format cells with large surface area to volume ratio- as well as for life modeling where temperature strongly influences the degradation rate, it becomes a major distinguishing feature for AutoLion™. In addition, AutoLion™ modeling framework naturally enables it for safety simulations where interaction of heat and battery reaction must be captured correctly. For more information, see this case study. 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 must be able to use AutoLion™ is our only product design rule. There are various resources available to shorten the learning curve for AutoLion™ that includes 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 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 to integrate Li-ion battery softwares 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 (for more information, see this document). 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 some standard experimental data. See this video to learn how AutoLion™ enables parameter extraction from experimental data and uses these input parameters reliably for a wide range of simulation conditions. 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™. Material properties as a function of temperature, Li concentration either in form of a function or a look up table can be easily inputted in AutoLion™ UDFs. The 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™ and AutoLion-ST™ have mixed material simulation capability. This capability is under implementation for AutoLion-3D™. To learn more, take a look at this video. Licensing What licensing options are available for AutoLion™ software? We offer node-lock as well as network licenses for AutoLion™. Annual licensing, as well as perpetual licenses, are available. Tech support and software upgrades come free with annual licensing options. For more information, please contact us at firstname.lastname@example.org. I need to change the location of my node-locked license. Can I obtain a new license for a new computer? Yes. To request a license re-location, please contact email@example.com. Installation and Hardware Requirements I only have access to a 32-bit computer. Will I be able to run any AutoLion™ software on this computer? No. AutoLion™ products (1D, ST, and 3D) are only compatible with 64-bit machines. I am having trouble installing Windows SDK 7.1 to use the UDFs with AutoLion™ 1D/ST. What should I do? Unfortunately, Windows SDK can be notoriously difficult to install due to some strange incompatibilities between various Microsoft products. These issues are well documented, and the best solution we have found can be accessed at this link. AutoLion-1D™ What is AutoLion-1D™? AutoLion-1D™ is a physics-based software to enable rapid battery material-to-cell scale up, cell design and optimization. AutoLion-1D™ allows users to easily simulate performance and life over a wide range of operating conditions for any battery chemistry. More information can be found here. Who should use AutoLion-1D™? AutoLion-1D™ is perfect for cell design engineers and scientists who are evaluating the applicability of various battery chemistries for their applications. R&D teams and design engineers can very easily and accurately simulate the impact of various chemistries (and any mixture of chemistries) on cell performance and life even before entering into a lab to fabricate a cell. AutoLion-1D™, with its easy-to-use and intuitive graphic interface, can be used by simulation experts as well as engineers and scientists who are not “modelers” with equal ease. Can I simulate behavior of a Li-ion battery under complex duty cycles with AutoLion-1D™? AutoLion-1D™ provides users with flexibility to simulate 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 current 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 that can be easily imported into Microsoft Excel or other plotting softwares such as Techplot, Origin, Ensight, etc. I just ran a simulation. Can I observe the temperature distribution in the cross-section of the cell? AutoLion-1D™ doesn’t provide temperature distribution in the cell. We have found, and it can be shown with very simple calculations, that the combination of high thermal conductivities of battery electrodes and the small thickness of these components (<100um) leads to minimal temperature distribution in cell thickness direction. However, if users are interested in studying the temperature distribution over the foot-print area, which can be substantial for large format cells, AutoLion-3D™ should be used. 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. However, the calendar life modeling capability is not yet implemented in AutoLion-1D™, but is available in AutoLion-ST™. AutoLion-ST™ What is AutoLion-ST™? AutoLion-ST™ is a software-in-the-loop tool for developing Li-ion battery system design and operational algorithms. AutoLion-ST™ is embedded in the MATLAB/Simulink environment. With this software, users can simulate fully functioning Li-ion battery systems complete with dynamic feedback and real-time control mechanisms to gain new insights into the intricate relationship between battery and system performance. More information can be found here. Who should use AutoLion-ST™? AutoLion-ST™ is ideally suited for system engineering and advanced engineering teams who are tasked with Li-ion battery based system architecture selection and system component trade-off as well as developing life and safety conscious operational algorithms. AutoLion-ST™ users can easily and reliably answer questions such as but not limited to 1) Which battery is best suited for my application?, 2) Which thermal management strategy should I use?, 3) How to best pair Li-ion battery with another energy source to optimize dynamic load distribution, etc. Read this story to find how AutoLion-ST™ offers a more cost and time-effective methodology for system design and engineering. Is AutoLion-ST™ an equivalent circuit model? No. AutoLion-ST™ is a physics-based, 1D electrochemical model which captures the mathematical non-linearities that arise during the course of Li-ion battery operation. This is in stark contrast to equivalent circuit models which use rudimentary algebraic relationships to approximate battery behavior by matching input parameters with empirical data. In this way, AutoLion-ST™ gives the user a quantum-leap in terms of flexibility, robustness, and accuracy, all while maintaining a high computational speed suitable for system/control development applications. For instance, it takes anywhere from days to months to fit experimental data to find good “R” and “C” element values to use equivalent circuit models. In addition, any slight change in cell design such as electrode thickness, particle size, etc that might be needed to adjust to changing system requirements means the whole fitting process needs to be repeated again. With AutoLion-ST™, there is no need for fitting parameters and any changes in cell design can be incorporated within seconds. Can I use AutoLion-ST™ for cell-level modeling? Yes. AutoLion-ST™ is based on the mathematical framework of AutoLion-1D™ and can do everything that AutoLion-1D™ can. In addition, AutoLion-ST™ allows users to utilize the various input and post-processing capabilities of MATLAB/Simulink. How does AutoLion-ST™ interact with the MATLAB/Simulink Environment? AutoLion-ST™ comes in the form of a Simulink S-Function, which calls a .mex64 file found in the AutoLion-ST™ installation directory. This enables full integration with Simulink, and gives the user unlimited flexibility when it comes to Li-ion battery system/control development. For more information on S-Functions, please visit the MathWorks website. I am not using the latest version of MATLAB. Is AutoLionST™ compatible with my version? AutoLion-ST™ is compatible with MATLAB versions starting with 2010bSP2 up to and including 2014a. I am interested in simulating a hybrid system that has more than one energy source. How will AutoLion-ST™ be helpful? Hybrid systems with at least one energy storage unit of a Li-ion battery can be easily simulated with AutoLion-ST™. A Li-ion battery block from AutoLion-ST™ can be easily paired with other components in the Simulink environment to evaluate system hybridization strategy over life. In addition, users can link AutoLion-ST™ to any system level simulation platform as long as Simulink is compatible with it. For example, refer to this case study on fuel cell-Li-ion battery hybrid powertrain simulation. I am running a simulation with the pack model turned on. Can I observe the behavior of individual cells in the pack? No. AutoLion-ST™ pack model assumes the behavior of all of the cells to be the same. Using this approach, there are no simulated performance differences between the individual cells. However, simulating the behavior of multiple cells in a pack can be easily done by using multiple S-Function blocks within the Simulink workspace. This will allow the user to not only observe performance differences between each cell in a pack, but also how these differences influence the aging and life-cycle of the pack. To learn more about this capability, please contact us at firstname.lastname@example.org. AutoLion-3D™ What is AutoLion-3D™? AutoLion-3D™ is a CFD-based software ideal for cell and pack safety simulations, pack thermal management and for evaluating three-dimensional distributions (of current, temperature, Li concentration, etc.) that are of importance for large-format Li-ion cells. On the execution level, AutoLion-3D™ functions as a plug-in library to any commercial CFD solver wherein governing equations of AutoLion-3D™ are solved with the robustness of the commercial CFD solver. More information can be found here. Who should use AutoLion-3D™? AutoLion-3D™ is the software for engineers and scientists who are focusing on evaluating cell/pack safety or pack-level thermal management issues and designing solutions. AutoLion-3D™ enables users to reliably evaluate challenges associated with safety and thermal management as well as evaluate the effectiveness of various solutions even before conducting any experiments. Basic working knowledge of CFD is needed to efficiently utilize the AutoLion-3D™ software. 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 that it is 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 model, any types 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 mesh, AutoLion-3D™ also provides advanced automated mesh generation for a cell model if the user has Ansys ICEM installed and it can 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 pack model, the temperature distribution in each cell is solved in three-dimension but cell electrochemistry is solved only in the cell thickness direction. In cell model, both electrochemistry and temperature are solved in true 3D space. This simplification for pack model allows more computational efficiency. We recommend use of “cell model” when a user is interested in studying 3D effects of cell electrochemistry and pack model is most efficient for other purposes such as safety simulation (More information on pack and cell models can be found in this document). 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 and physics based. 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 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. A specific version of Intel® MKL is distributed along with the AutoLion-3D™ package and you should use that version. 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 platforms) 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 and can be downloaded from here. Which types of data are output in the CGNS files for the single cell model? The data outputted in CGNS is 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 do not have any 3D post-processing software. What can I use to view my simulation results? CGNS file 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.