3D Quantification of Microstructural Properties of LiNi0.5Mn0.3Co0.2O2 High-Energy Density Electrodes by X-Ray Holographic Nano-Tomography

Despite significant progress in the field of tomography, capturing the carbon binder domain (CBD) morphology presented in the Li-ion electrode remains challenging, due to its low attenuation coefficient. In this work, quantitative phase contrast X-ray nano-holotomography is used as a straightforward approach that provides a large reconstructed volume, where the CBD can be resolved along with the active materials and the pore space. As a result, a complete quantitative analysis of the microstructures of three LiNi0.5Mn0.3Co0.2O2 high energy density electrodes, including the characterization of each phase separately along with the statistical quantification of their inter-connectivity at particle scale, is performed. The microstructural heterogeneities are quantified and comparison between different electrodes is done. The results from this work suggest reasons for the negative impacts of the CBD excess on the electrode performance at high C-rates. Those results are true in the case of high energy density electrodes, and are due to the reduction of the electrochemical active surface area. This sheds light on the optimization of the electrode design to improve the power rate of high energy density electrodes.

Automated summary

Quantitative phase contrast X-ray nano-holotomography was used to analyze the microstructures of high energy density Li-ion electrodes, revealing the negative impacts of excess CBD on electrode performance and offering insights for electrode design optimization.