A. Bertei Mathematical Modelling of an Innovative Solid Oxide Fuel Cell
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ABSTRACT
A mathematical model of an innovative solid oxide fuel cell (IDEAL-Cell), made of the combining of the cathodic compartment of a conventional anionic-conducting SOFC with the anodic compartment of a protonic-conducting one (PCFC), is presented. The special feature of the cell is represented by the central membrane, i.e. the porous composite layer that joins cathodic and anodic compartments.
The model describes transport phenomena and kinetics inside the central membrane in steady-state and transient conditions. A specific model to estimate morphological parameters, based on an extension of percolation theory and on 3D simulations of random packing of overlapping spheres, is also presented.
The modelling development is connected with the project “Innovative Dual mEmbrAne fueL-Cell”, a collaborative project funded by the European Commission within the Seventh Framework Programme (2008-2012). The proof of concept has been demonstrated experimentally, some measurements of the performances of the cell have been already performed by changing some parameters (e.g. operating conditions, preparation procedures, etc.) but improvements on materials, preparations and understanding of all mechanisms are still needed.
The model is validated with first experimental results. Simulations show the effects of cell design, dimensions of powders, porosity, etc. on the global performances; a sensitivity analysis on unknown or uncertain parameters is presented too. At this state of the art, central membrane is in ohmic regime, improvements are required to reduce the thickness of layers and to increase effective conductivities. Specific experiments must be performed to obtain a stronger validation and to estimate unknown parameters.
Model and submodels are valuable tools to interpret experimental data, to optimize the cell design and to predict future performances and developments.
Keywords: Mathematical modelling, Fuel Cell, SOFC, IDEAL-Cell, Morphology