Fabrication of seven cells in single tubular solid oxide fuel cell using multi-pass extrusion process

A solid oxide fuel cell (SOFC) with high specific electrolyte surface area was fabricated using the multi-pass extrusion process. The cell configuration was NiO-YSZ/YSZ/LSM. In this design, one tube contained 7 individual fuel cells. The outer diameter of the tube was 5 mm and 4.1–4.2 mm after extrusion and sintering, respectively. The length of the cell was optimized to 3–5 cm with continuous channels of 400–450 μm in diameter. The porous microstructures of the anode and the cathode and the dense microstructure of the electrolyte were observed by scanning electron microscopy. The relative density of the electrolyte was >96% and the thickness was 15–20 μm. The XRD profiles indicated no undesirable phases after co-sintering at 1300 °C.