COMSOL Day: Battery Design

Understanding the coupled physical phenomena that govern battery performance is essential when using modeling and simulation for battery research and design. Electrochemical reactions, species transport, heat generation, fluid flow, and mechanical effects can all influence battery capacity, power, lifetime, and safety. To account for these interactions, scientists and engineers rely on the multiphysics modeling capabilities of the COMSOL Multiphysics^® software.

Battery models can be used at different levels of detail, from studying processes within porous electrodes and individual cells to analyzing thermal management at the module and pack levels. Modeling can also provide insight into degradation mechanisms and support the evaluation of operating strategies and design alternatives. In addition, surrogate models can accelerate computationally intensive analyses and make detailed battery models available through fast and easy-to-use simulation apps.

In this session, we will provide an overview of how multiphysics modeling, simulation apps, and surrogate models can support battery design and analysis. We will also introduce the specific topics covered throughout this COMSOL Day, including the fundamentals of battery design, battery modeling in COMSOL Multiphysics^®, degradation, thermal management, and the acceleration of simulation apps using surrogate models.

In this session, we will introduce the Battery Design Module, an add-on to COMSOL Multiphysics^® that provides functionality for simulating operational aspects of battery systems ranging from single cells to packs of hundreds.

We will demonstrate this functionality by simulating a lithium-ion battery, using the COMSOL^® software's unique multiphysics capabilities to take electrochemistry, heat transfer, and fluid flow into account. We will then show how easy it is to simplify the model using lumped modeling to ultimately create a pack model with hundreds of batteries.

We will also explain how battery systems can be modeled using time-dependent studies to incorporate transient effects like charge–discharge cycles, as well as how to model electrochemical impedance spectroscopy with a frequency-domain formulation.

Simulation-data-driven surrogate models in COMSOL Multiphysics^® significantly increase computational speed while maintaining the same accuracy as high-fidelity multiphysics models within their applicable data ranges, making them useful for efficiently approximating simulation results.

COMSOL Multiphysics^® provides an ideal environment for generating the physics-based training data used by surrogate models. These models can be incorporated into simulation apps, leading to a more interactive user experience and encouraging broader use of simulation within organizations. Surrogate models can also be used to accelerate uncertainty quantification analyses and multiphysics modeling.

Join this session to learn more about creating surrogate models. We will present techniques for effective data generation using design of experiments methods and walk through the subsequent steps for training a surrogate model. We will also demonstrate how to incorporate surrogate models into simulation apps.

A battery's performance is often limited by degradation mechanisms and parasitic reactions at the electrodes. To help designers address these limitations, the Battery Design Module provides functionality for modeling battery aging and capacity fade. The module's flexibility makes it possible to include arbitrary side reactions, such as hydrogen and oxygen evolution, solid electrolyte interphase (SEI) growth, lithium plating, metal corrosion, and graphite oxidation. Mechanical degradation associated with electrode expansion and contraction can also be incorporated into battery models.

This session will provide an overview of the Battery Design Module's capabilities for modeling battery degradation and will demonstrate how to build and simulate a capacity fade model.

Thermal management is a key aspect of battery design, from individual cells to complete battery packs. At the cell level, current-density distributions influence heat generation, hotspot formation, and the risk of thermal runaway. At the pack level, busbar design, electrical load distribution, and active or passive cooling determine the thermal performance of the battery system.

The Battery Design Module provides functionality for coupled electrochemical and thermal modeling at both the cell and pack levels. Electrochemical heat generation can be included in detailed cell models, while battery packs containing hundreds of cells can be modeled using reduced-order electrochemical models coupled to anisotropic heat transfer modeling.

This session will provide an overview of the Battery Design Module's capabilities for coupled electrochemical and thermal analysis, including thermal management of battery cells and packs, thermal runaway, and mitigation strategies.