Optimization and demonstration of a solid oxide regenerative fuel cell system

Abstract

Single cell Solid Oxide Regenerative Fuel Cells (SORFC's) have been demonstrated for over 1000 hours of operation at degradation rates as low as 0.5% per 1000 hours for current densities as high as 300 mA/cm2. Efficiency levels (fuel cell power out vs. electrolysis power in) have been demonstrated as high as 70% at 300 mA/cm2. All testing has been performed with metallic interconnects and non-noble metal electrodes in order to limit fabrication costs for commercial considerations. A self contained SORFC system requires efficient thermal management in order to maintain operating temperatures during exothermic and endothermic operational modes. Thermal storage experiments were performed using lithium fluoride (LiF) as a phase change material (PCM). The thermal storage concept was deemed to be technically viable for well insulated systems in the multi-kW size range.