Performance of Anode-Supported Solid Oxide Fuel Cell with Ni-YSZ or Ni-Ceria Anode Modified by Sol-Gel Coating Technique

摘要

Anode-supported solid oxide fuel cells based on thin yttria-stabilized zirconia electrolyte (8 mol%; YSZ and thickness; 30 μm) were prepared by wet-process. The both La_(0.85)Sr_(0.15)MnO_3 (LSM) cathode and Ni/YSZ anode were modified by coating with samaria-doped ceria (SDC, Sm_(0.2)Ce_(0.8)O_2) sol in order to increase the triple phase boundary (TPB) between air or fuel, electrode, and YSZ electrolyte. As a result of the impedance analysis of symmetric anode cells coated with SDC sol, the electrode polarization (R_p) was 4-times lower than that of the sate-of-the art anode. Especially, the SDC coating on the anode resulted in good stability for long-term operation due to little carbon deposition and nickel sintering. The maximum power density of the anode-supported cell with the modified anode was about 0.3 W/cm~2 at 700°C in the mixture of methane (25%) and air (75%) as the fuel and air as the oxidant. The cell has been operated for 1,000 h without significant degradation of cell performance.