Electrochemical Analysis of Anode Supported PCFC with Pseudo Symmetrical Cell

Protonic Ceramic Fuel Cell (PCFC) is expected to be the next-generation fuel cell for its higher energy conversion efficiency and lower operation temperature. BaZrO 3 based oxide are potential materials as PCFC electrolyte because they have a high chemical stability under CO 2 condition and high proton conduction. Recently, we have developed PCFC using BaZr 0.8 Yb 0.2 O 3-δ (BZYb) as the electrolyte. The proton conductivity of the BZYb pellet was 1.1×10 -2 S/cm at 600℃ and did not form the complex oxide with NiO. The power density of the developed cell (Ni-BaZr 0.8 Yb 0.2 O 3-δ | BaZr 0.8 Yb 0.2 O 3-δ | La 0.6 Sr 0.4 CoO 3-δ ) achieved 0.49 W/cm 2 at 600℃.To improve the performance of anode supported PCFC, anode supported pseudo symmetrical cell: Ni-BaZr 0.8 Yb 0.2 O 3-δ | BaZr 0.8 Yb 0.2 O 3-δ | Ni was manufactured and analyzed by impedance spectroscopy under the various conditions and temperatures.The thickness dependence of the ohmic resistance was measured for three types of electrolyte (thickness: 8 μm, 16 μm and 25 μm) under 48%H 2 -49%N 2 -3%H 2 O gas condition at 300-700℃. The conductivity was calculated from the relation between electrolyte thickness and the ohmic resistance, which was 0.35×10 -2 S/cm at 600℃. The degradation of proton conductivity occurs due to Ni dissolution. The performance of anode supported PCFC might be improved further if the Ni dissolution to electrolyte can be inhibited. Figure 1