Investigation of Microstructural Impacts on Ionic Transport in Li₇La₃Zr₂O₁₂-LiCoO₂ Composite Structures

The ionic transport property of a solid composite cathode is sensitive to its microstructure, which has a critical impact on variability of the overall solid-state battery performance. In this presentation, we will discuss our recent microstructure-aware modeling effort on unraveling the relationship between microstructural features and effective ionic transport properties. Specifically, using Li₇La₃Zr₂O₁₂-LiCoO₂ composite cathode as a model system, we combine atomistically informed mesoscale modeling approach and machine learning (ML) analysis to examine how the local transport properties of individual microstructural constituents and their topological features affect the effective diffusivity of Li in the two-phase composites. In addition, our ML analysis identifies key microstructural descriptors for the effective transport property. Our framework can be extended for elucidating the intricate microstructure-transport property relationship in generic multiphase materials, which offers insights highlighting the importance of microstructure engineering in tuning the properties of composite materials in diverse energy applications.<br/>This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.