A simple analysis of current collection in tubular solid oxide fuel cells

A transmission line analysis is presented for the axial current collection in tubular solid oxide fuel cells (SOFC). Closed form analytical solutions are obtained for two modes of current collection: (1) Current collection at one end. (2) Current collection across opposite ends. The analysis shows that cell resistance is lower for current collection at one end compared to that at the opposite ends, with the best case scenario being current collection at both ends. In addition, the analysis shows that for the case of tubular cells, performance may not indefinitely increase with increasing temperature. Experimental data are presented on planar and tubular cells that demonstrate significant differences in temperature dependence. It is projected that under certain conditions, performance of tubular cells may actually decrease with increasing temperature. A design of tubular cells with spines which can substantially lower current collection losses is described.