The properties and performance of micro-tubular (less than lmm od) anode supported solid oxide fuel cells

Abstract

The sub-millimeter range micro-tubular SOFCs have been modeled, designed and tested in the intermediate temperature range of 450∼550°C. The results of a two-dimensional, steady state, non-isothermal computational model incorporating radiation, heat transfer, flow and transport of species in the porous gas diffusion electrodes are presented and compared to the experimental data. Considering different current collecting techniques the model estimates the loss of performance for a single cell as a function of anode tube length and thickness. The results showed that for the 0.8 mm diameter tubular SOFC with a length of 1.2 cm the performance loss is 0.8, 2.0, and 4.6 % at 450, 500, and 550°C respectively. The mechanical tests with electrolyte coated Ni-GDC anode pellets indicate that the micro- and nano-hardness of GDC is comparable or higher than that of YSZ. In the intermediate temperature range of 450∼550°C the performance of 0.8 mm diameter micro-tubular ceria-based SOFCs was found to be between 110∼350 mWcm-2. Copyright © 2007 MS&T'07®.