Modeling Electrodeposition in 3D Porous Architectures for Li-Metal Batteries

Several strategies have been developed to mitigate the dendritic growth of metallic lithium. One promising approach is the use of three-dimensional (3D) framework electrodes for lithium-metal storage. These electrodes feature a large surface area and high porosity, which help to reduce local lithium plating current densities. Their porous topology acts as a scaffold for lithium deposition and stripping, thereby enhancing both mechanical integrity and lithium accessibility. The objective of this study is to identify the characteristics—such as geometry and material properties—necessary for achieving stable cycling at current densities relevant to vehicle electrification. To accomplish this, we have developed a computational method to track material growth driven by electrodeposition within complex geometries. This method involves adapting a background mesh to the evolving volume of material, ensuring that the finite-element discretization remains conforming to the moving boundary. With these new tools, we analyze the conditions under which porous anode architectures effectively self-regulate current density and mitigate dendrite growth. One criterion consists in analyzing the maximum and the spatial distribution of the local overpotential, since it directly relates to the likelihood of dendrite growth. Finally, we investigate the trade-offs between surface area, energy density, and mechanical robustness in the design of microstructures for anode-free batteries. This work was supported by Lawrence Livermore National Laboratory LDRD SI 23-SI-002. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.