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

电池已经成为我们现代生活中不可或缺的商品，为手机、笔记本电脑、电动工具和电动汽车供电。电池的关键部件是电极，它由堆积的锂存储粒子组成。因此，电极具有复杂的微观结构，具有卷曲的空间和不规则的粒子。电池的充放电过程涉及到离子和电子在复杂电极上迁移的耦合物理机制。因此，由于这些复杂性，研究电池现象变得具有挑战性。这个项目的目标是使用MFEM （BESFEM）开发一个开源的电池电极模拟工具包。该工具包将使复杂电极微结构的电化学过程的快速模拟。它将对实验重建的电极微结构进行详细的模拟，结果可以在虚拟现实环境中可视化。用户将能够以数字方式探索各种微结构和不同循环条件下的电化学过程。这个软件不仅可以作为提高电池性能和减少电池故障的设计工具，而且还可以作为培训材料科学家的教育工具。这项工作将加速美国汽车工业和电网级储能的电池发展。传统的锐界面模拟需要符合感兴趣域的网格系统来求解控制方程。然而，为复杂的微结构生成网格是一项具有挑战性的任务。为了解决这个问题，我们的研究团队采用了光滑边界方法（SBM），该方法利用连续域函数来描述几何形状并重新制定相关的电化学控制方程。该公式可以在规则的笛卡尔网格上求解新方程，从而消除了对符合体的网格的需要。值得注意的是，SBM方程可以直接在重建的三维微结构体素数据上求解，大大减少了模拟准备时间。BESFEM将SBM方法集成到MFEM求解器库中，该库是美国能源部百亿亿次计算项目的一个产品。为了提高精度和计算效率，我们的团队将利用MFEM的混合阶单元功能，其中SBM漫射界面附近的元素被分配为高阶形状函数。MFEM已经证明了其可扩展性，以百万计的并行CPU任务，也支持GPU计算。因此，BESFEM将大大加快电极微观结构模拟的速度和规模。这种能力将允许BESFEM进行高通量型微观结构模拟，以提取电极的结构-性能关系。拟议的软件开发将遵循软件工程的最佳实践，该产品将作为电池科学和材料科学社区的研究和教育工具完全可用。该合同由先进网络基础设施办公室颁发，由工程理事会化学、生物工程、环境和运输系统部门以及电化学系统项目联合支持。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.