Reaction-diffusion of fuel with air between planar solid oxide fuel cells stacked with ceramic felt

Solid oxide fuel cells (SOFC) hold great promise for reducing global air pollution, but the cost and fragility of current stacks is severely limiting the number of potential applications. This paper reports a new system devised to overcome these problems by stacking the zirconia plates together using a porous ceramic felt material. A sub-unit of this stack has been experimentally tested and mathematically modelled as a reaction-diffusion system. A novel transition layer solution was derived which predicted the experimentally measured trends in electrode potential as a function of position on the zirconia plate, plate sire, fuel feed rate and ceramic felt thickness. The conclusion was that the mathematical solution gave an adequate description of the observed behaviour and could be used to design planar SOFC stacks (and related reaction-diffusion systems) where plate-centre reactant feeds are used.