As alternative and low carbon energy technologies are of increasing international importance there is considerable debate as to the most appropriate technology solutions for power generation. For a distrubted generation scenario with power output in the range of kW to MW the solid oxide fuel cell (SOFC) is a leading contender, with development undertaken by many international companies. One of the areas of concern with new technologies is the lifetime of the device and as SOFCs operate at elevated temperatures any degradation of components may be accelerated. Due to the complexity of these devices there has been limited scope to analyse the operation of the SOFC in-situ, and from this determine mechanistic information on degradation processes. It is the aim of this proposal to tackle this challenge.Degradation and reactivity of solid oxide fuel cells may be characterised by processes occuring on a variety of length scales, from chemical reactivity and diffusion processes on the atomic scale through surface chemsitry, stress in functional layers and thermal management over mm and cm. Each of the processes contributes to the overall cell degradation, but may evolve differently depending on the functional component concerned - hence anode and cathode processes will be significantly different. As these are complex devices characterising these processes and the origin of them is challenging and currently results from post-mortem analysis. Whilst this is one route to understanding the failure of devices, an in-situ characterisation under operating conditions will provide detailed direct understanding. Our approach is to develop a combination of complimentary techniques that will allow detailed study of device operation using diffraction, spectroscopy, ion scattering, modelling and emissivity measurements. We will tackle known degradation issues in fuel cells including carbonate and Cr poisoning of cathodes, carbon formation on anodes and electrode delamination and will interact strongly with the UK Supergen Fuel Cells programme. As a result of this programme we will be able to inform industrial partners of mitigation strategies to minimise device degradation and use this information in development of new materials.

Fuel Cells continue to receive considerable attention as clean, highly efficient devices for the production of both electricity and, for some applications, high grade waste heat. However, considerable technical challenges remain for fuel cell to achieve greater penetration into commercial markets. It is worth emphasising the shift in research landscape within which the Supergen fuel cell consortium is operating. As fuel cell technology continues to mature, the fuel cell research community is being asked to place increasing emphasis on improving its fundamental understanding of materials behaviour under realistic operating conditions and duty cycles, especially where this relates to failure modes, and materials/cell degradation. Thus the work programme of this second phase will very much focus on generic and fundamental research, targeted onto real problems identified in discussion with our industry partners. This means that during this second phase, it will remain the case that the Supergen consortium will put an emphasis on knowledge transfer to industry, though of course patents will be filed where appropriate. It is then largely the responsibility of the industry partners to exploit this knowledge in the context of their own technology programmeThe proposed second phase of the Supergen fuel cell consortium refreshes the membership, with three new academics; Kucernak (Imperial), Brett (UCL) and Elliott (Cambridge) and with four academic teams continuing; Brandon (Imperial), Scott (Newcastle), Atkinson (Imperial) and Irvine (St Andrews). All three industry partners remain within the consortium for its second phase; Rolls-Royce Fuel Cell Systems, Ceres Power and Johnson Matthey, with the addition of a fourth new industry partner, Intelligent Energy. This new team maintains the consortium strength in Solid Oxide Fuel Cells, whilst adding significant extra capacity in Polymer Fuel Cells within both the industry and academic teams. This provides a shift in emphasis within the consortium to developing an improved understanding of failure modes and performance limitations within current fuel cell devices, and the need for greater scientific understanding to tackle these failure modes. In addition the consortium will continue to deliver its training courses in fuel cell science and engineering to consortium staff and students, external researchers to the consortium and to appropriate Doctoral Training Centres and to disseminate the work of the consortium (through publication and conference presentation, including an annual open conference) and to extend its international collaboration.