Metal-supported solid oxide fuel cells operated in direct-flame configuration

Metal-supported solid oxide fuel cells (MS-SOFC) with infiltrated catalysts on both anode and cathode side are operated in direct-flame configuration, with a propane flame impinging on the anode. Placing thermal insulation on the cathode dramatically increases cell temperature and performance. The optimum burner-to-cell gap height is a strong function of flame conditions. Cell performance at the optimum gap is determined within the region of stable non-coking conditions, with equivalence ratio from 1 to 1.9 and flow velocity from 100 to 300 cm s⁻¹. In this region, performance is most strongly correlated to flow velocity and open circuit voltage. The highest peak power density achieved is 633 mW cm⁻² at 833 °C, for equivalence ratio of 1.8 and flow velocity of 300 cm s⁻¹. The cell starts to produce power within 10 s of being placed in the flame, and displays stable performance over 10 extremely rapid thermal cycles. The cell provides stable performance for >20 h of semi-continuous operation.