Effects of electrode composition on the electrochemical performance and mechanical property of micro-tubular solid oxide fuel cell

Micro-tubular solid oxide fuel cell (mtSOFC) with tubular diameter under a few millimeters shows high performance on thermal shock resistance, volumetric power density, fast startup and thermal cycling. A finite element method based multi-physics electrochemistry and structural mechanics model is built for mtSOFC with the effective properties linked to the electrode microstructures. The theoretical model is verified to produce I – V relations that are in good agreement with the experiment. The model is used to examine systematically the effects of the composition and particle size of electrode materials on the electrochemical and mechanical properties of mtSOFC. It is found that low Ni content and both high and low LSM contents are detrimental to the electrochemical performance, while the mechanical stability decreases dramatically with the increased Ni content. The suitable electrode compositions beneficial for high electrochemical performance while maintaining desirable mechanical properties are obtained by the modeling analysis. ► A multi-physics numerical model for micro-tubular SOFC is presented. ► Effects of electrode composition on mechanical property are critically examined. ► The sizes of electrode particles affect greatly the electrochemical performance. ► Optimal composition and particle size of electrode materials are described.