X-ray diffraction computed tomography for structural analysis of electrode materials in batteries

We report the use of X-ray diffraction in combination with computed tomography to provide quantitative information of a coin cell Li-ion battery and a commercial Ni/MH AAA battery for the first time. This technique allows for structural information to be garnered and opens up the possibility of tracking nanostructural changes in operandi. In the case of the cylindrically wound, standard AAA Ni/MH cell, we were able to map all the different phases in the complex geometry, including anode, cathode, current collector and casing, as well as amorphous phases such as the binder and separator. In the case of a Li-ion coin cell battery, we show how the X-ray diffraction tomography data can be used to map crystal texture of the LiCoO₂ particles over the cathode film. Our results reveal that the LiCoO₂ microparticles show a high degree of preferred orientation, but that this effect is not homogenous over the film, which may affect the electrochemical properties.