Cell performance of SOFC using CH4–CO2 mixed gases

Cell performance was measured for a solid oxide fuel cell with dense gadolinium-doped ceria (GDC) electrolyte, Ni–GDC anode and (La0.8Sr0.2)(Co0.8Fe0.2)O3 cathode using CH4–CO2 mixed gases. The power density of SOFC increased with increasing CH4 concentration (30–60 vol%) of CH4–CO2 gas. The maximum powder density was 334 mW/cm2 at 800 °C for a 60 vol% CH4 fuel. The outlet gas contained CH4, CO2, H2, CO and O2 gases. No degradation of cell performance at 800 °C was measured for 50 h when 50–70 vol% CH4 fuels were supplied. A part of supplied CH4 gas was decomposed to form graphite and a H2 fuel at the anode. However, no blockage of outlet gas was measured for 50 h.