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Latest work on diffraction tomography of a commercially-available cylindrical NMC liion battery

We are excited to share with you our work on a commercially-available cylindrical NMC li-ion battery using XRD-CT. The paper, entitled “Cycling Rate-Induced Spatially-Resolved Heterogeneities in Commercial Cylindrical Li-Ion Batteries, was published as open access in Small Methods: https://onlinelibrary.wiley.com/doi/10.1002/smtd.202100512. The work was led by our R&D Lead Scientist Dr Antony Vamvakeros and Dr Dorota Matras (Faraday Institution/Diamond Light Source) and was performed in collaboration with DESY, UCL Chemistry and SciML.

Synchrotron high-energy X-ray diffraction computed tomography has been employed to investigate, for the first time, commercial cylindrical Li-ion batteries electrochemically cycled over the two cycling rates of C/2 and C/20. This technique yields maps of the crystalline components and chemical species as a cross-section of the cell with high spatiotemporal resolution (550 × 550 images with 20 × 20 × 3 µm3 voxel size in ca. 1 h). The recently developed Direct Least-Squares Reconstruction algorithm is used to overcome the well-known parallax problem and led to accurate lattice parameter maps for the device cathode. Chemical heterogeneities are revealed at both electrodes and are attributed to uneven Li and current distributions in the cells. It is shown that this technique has the potential to become an invaluable diagnostic tool for real-world commercial batteries and for their characterization under operating conditions, leading to unique insights into “real” battery degradation mechanisms as they occur.

Read the full paper at https://doi.org/10.1002/smtd.202100512

Watch recorded webinar on Chemical Tomography and Neural Networks

Our Research and Development Lead Scientist Antony Vamvakeros gave a webinar on chemical tomography and neural networks on the 20th May hosted by the Neel Institut

Synchrotron X-ray chemical tomography methods combine a scattering or spectroscopic technique with a tomographic data acquisition approach. These non-destructive methods yield a cross-section of the studied sample where each pixel in the reconstructed images corresponds to a chemical signal (e.g. X-ray diffraction pattern or spectrum). These spatially-resolved signals most often reveal information that is lost in conventional bulk measurements. In this talk, he briefly introduces X-ray diffraction computed tomography (XRD-CT) and presents a few examples where we have applied such methods to track the evolving solid-state chemistry of complex functional materials and devices under operating conditions. In the second part of the webinar, he focuses on our latest technical advances regarding processing and analysis of these large and rich chemical imaging datasets using deep learning methods with neural networks.

Watch a recording of the webinar below:

Our paper on the first X-ray diffraction tomography experiment of real-life size micro-tubular SOFC has been published in Nature Communications

Figure various micro-monolithic anode supports after sintering

Various micro-monolithic anode supports after sintering at 1450 °C. SEM images of central-axis-view of: a 3, b 4, and c 7 channels; Cross-sectional images of d sponge between the shell and two channels in the 7-channel anode, e sponge between the central channel and surrounding two channels in the 7-channel anode; f close-up image of anode/electrolyte interface

Our new work on a state-of-the-art SOFC has been published in a paper Design of next-generation ceramic fuel cells and real-time characterization with synchrotron X-ray diffraction computed tomography in Nature Communications.

Solid oxide fuel cells offer a clean and efficient means of producing electricity through a variety of fuels. However, miniaturization of cell dimensions for portable device applications remains a challenge, as volumetric power densities generated by readily-available planar/tubular ceramic cells are limited. In our work, we demonstrate a concept of ‘micro-monolithic’ ceramic cell design and evaluate the mechanical robustness and structural integrity of this design, for the first time, with synchrotron X-ray diffraction computed tomography. The successful miniaturization results in an exceptional power density of 1.27 W cm−2 at 800 °C, which is among the highest reported. This holistic design incorporates both mechanical integrity and electrochemical performance, leading to mechanical property enhancement and representing an important step toward commercial development of portable ceramic devices with high volumetric power (>10 W cm−3), fast thermal cycling and marked mechanical reliability. This is also the first time a real-life size solid oxide fuel cell has been investigated in situ demonstrating that such experiments are now possible, adding a very powerful characterisation tool for the SOFC community in general.

The synchrotron experiments were conceived, designed and performed by Dr Antony Vamvakeros and Dorota Matras in collaboration with a team from the Electrochemical Innovation Lab (EIL) from UCL Chemical Engineering using ESRF’s ID15A beamline using a state-of-the-art SOFC designed by Imperial College.

Read the full article at https://www.nature.com/articles/s41467-019-09427-z

Read more about it at http://www.esrf.eu/sites/www/home/news/general/content-news/general/real-time-characterisation-of-a-new-miniature-honeycomb-fuel-cell-shows-its-outstanding-properties.html