Renewable Energy and Energy Storage

It is clear by now that the supply of fossil energy is limited. Furthermore, returning large quantities of carbon dioxide to the atmosphere increases the amount of energy that it absorbs from the sun with consequences for the balance of our planet’s climate systems. There is a need to develop alternative sources of energy and to ensure that energy, irrespective of its source, is used as efficiently as possible, which then results in that energy having to be stored, delivered and converted into heat, light or motion with minimal losses. 

Materials research is at the heart of developments for modern energy systems. The ESRF offers the possibility of studying energy producing or energy storage systems, from photovoltaic panels, to fuel cells or rechargeable batteries or even hydrogen-storage materials. Some of the techniques that can be used are:

  • Diffraction and spectroscopy to reveal the composition, atomic structure and crystalline state of materials.
  • Imaging of materials to track defects and aggregates. 
  • In situ studies to follow materials like batteries under operating conditions or to watch the evolution of components.

 

Company or institute

Imperial College London and Finden

Challenge

To carry out a complete physical and chemical characterisation of an operating ceramic fuel cell, in particular, probing its 3D structure, chemical homogeneity, and mechanical robustness.

Sample

The sample was a miniaturised ceramic solid oxide fuel cell (SOFC) designed for portable applications. Its operating temperature is 800°C.

Solution

A combination of techniques were used together at beamline ID15A. Micro computed tomography (micro-CT) was used to obtain the morphology of the cell, while X-ray diffraction computed tomography (XRD-CT) was used to map the chemical species present within the materials.

 

Combined micro-computed tomography and X-ray diffraction computed tomography images of the SOFC in cross section.

Combined micro-computed tomography and X-ray diffraction computed tomography images of the SOFC in cross section. XRD-CT maps of cathode LSM (green), electrolyte YSZ (red) and anode NiO (blue) have been overlaid on top of a micro-CT image collected at the same position along the cell. The scale bar corresponds to 0.5 mm. Image credit: T. Li et al., Nature Communications 10, 1497 (2019).

Benefits

Micro-CT provided a detailed view of the morphology of the cell, mapping its porous structure and verification that this was unchanged by thermal cycling. In situ XRD-CT provided a confirmation of stability of the materials, by monitoring the crystallographic properties during thermal cycling. From the XRD-CT data, a map of the three electrochemical components of the cell was produced and it was even possible to identify minor phases such as SrO present at < 3 wt.%. Also, the activation of NiO to Ni was observed in the reduction step before cycling.

The combination of techniques provided a unique insight into the functioning of a novel SOFC, demonstrating a very powerful technique to study fuel cells under operando conditions.

Reference

Design of next-generation ceramic fuel cells and real-time characterization with synchrotron X-ray diffraction computed tomography, T. Li, T.M.M. Heenan, M.F. Rabuni, B. Wang, N.M. Farandos, G.H. Kelsall, D. Matras, C. Tan, X. Lu, S.D.M. Jacques, D.J.L. Brett, P.R. Shearing, M. Di Michiel, A.M. Beale, A. Vamvakeros and K. Li, Nature Communications 10, 1497 (2019); doi: 10.1038/s41467-019-09427-z.