Characterization and Modeling of NMC Particle Architectures

The sub-particle architecture of LiNixMnyCozO2 (NMC) considerably influences the performance of electrodes in Li-ion batteries, yet quantifying sub-particle properties and identify favorable particle architectures remains extremely challenging. In this presentation, progress towards quantifying sub-particle properties that are relevant to the electrochemical and mechanical performance of NMC particles will be covered. Techniques include using accessible and high-throughput 2D electron backscatter diffraction (EBSD) and 3D focused ion beam (FIB) EBSD to quantify the morphology and orientations of sub-particle crystallographic grains. Furthermore, using image-based NMC particle architectures, continuum-level models were developed to spatially and temporally resolve mechanical strain within NMC particles as the morphology of sub-particle grains evolves during lithiation and delithiation. A range of different image-based particle architectures with varying particle size and grain size were explored via continuum level models and the influence of sub-particle architectures on the life and high rate performance of electrodes is clarified.