Elements: Open-Source Battery Electrode Simulation Toolkit using MFEM (BESFEM)

Batteries have become an indispensable commodity in our modern lives, powering mobile phones, laptops, power tools, and electric vehicles. The crucial components of a battery are electrodes, which consist of packed lithium-storage particles. As a result, electrodes possess complex microstructures with convoluted spaces and irregular particles.

The charge-discharge processes in batteries involve coupled physics mechanisms of the migration of ions and electrons these complex electrodes. Consequently, investigating battery phenomena becomes challenging due to these complexities. The objective of this project is to develop an open-source Battery Electrode Simulation toolkit using MFEM (BESFEM).

This toolkit will enable rapid simulation of electrochemical processes in complex electrode microstructures. It will perform detailed simulations on experimentally reconstructed electrode microstructures, and the results can be visualized in a virtual-reality-like environment. Users will be able to digitally explore electrochemical processes in various microstructures and under different cycling conditions.

Not only can this software serve as a design tool for enhancing battery performance and mitigating battery failures, but it can also serve as an educational tool for training materials scientists. This work will accelerate battery development in the US automotive industry and grid-level energy storage.

Conventional sharp-interface simulations require mesh systems that conform to the domain of interest for solving governing equations. However, generating meshes for complex microstructures poses a challenging task. To address this, our research team employs the smoothed boundary method (SBM), which utilizes a continuous domain function to describe geometries and reformulate the relevant electrochemical governing equations.

This formulation enables solving the new equations on a regular Cartesian grid, eliminating the need for body-conforming meshes. Remarkably, the SBM equations can be directly solved on voxel data of reconstructed 3D microstructures, significantly reducing the time spent on simulation preparation. BESFEM integrates the SBM approach on the MFEM solver library, a product of the DOE's Exascale Computing Project.

To enhance accuracy and computational efficiency, our team will leverage MFEM's hybrid order cells functionality, where elements near SBM diffuse interfaces are assigned with high-order shape functions. MFEM has demonstrated its scalability to millions of parallel CPU tasks and also supports GPU computing. Consequently, BESFEM will greatly accelerate the speed and scale of electrode microstructure simulations.

This capability will allow BESFEM to conduct high-throughput-type microstructure simulations to extract the structure-performance relationship of electrodes. The proposed software development will follow the best practice of software engineering and the product will be made fully available as a research and education tool for the battery science and materials science communities.

This award by the Office of Advanced Cyberinfrastructure is jointly supported by the Division of Chemical, Bioengineering, Environmental, and Transport Systems, and the Electrochemical Systems program, within the Directorate for Engineering.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.