Measurement of gas permeability of porous anodes in solid oxide fuel cells

Abstract

The purpose of this study is to measure the permeability of a porous Ni–YSZ (yttria-stabilized zirconia) cermet used for SOFC anodes and to reveal the relationships between its microstructure and the permeability. Anode disks with different microstructure are prepared by changing the particle size and weight ratio of pore formers. The pressure difference formed between both sides of the anode disks is measured at various permeation flow rate of the air. Then, the permeability of each disk is calculated from Darcy’s law. It is found that the permeability increases as the average pore size increases. For instance, the permeability of the disk with the average pore size of 2.1 µm is 3.4 × 10^-14-14 m² , whereas that with the average pore size of 0.69 µm is 4.4 × 10^-16 m² .