Fabrication of needle-type micro SOFCs for micro power devices

We report the world smallest tubular solid oxide fuel cell – needle-type micro SOFCs applicable to micro power devices. The anode-supported cell was prepared using cost effective, conventional extrusion and dip-coating techniques. The diameter of the needle-type cell is 0.4 mm, consisting of NiO-Gd doped Ceria (GDC) for anode (under 100 μm thick), GDC for electrolyte (8 μm thick), and (La, Sr) (Co, Fe)O3 – GDC for cathode. The cell performances of 80, 160 and 300 mW cm−2 at 450 °C, 500 °C, and 550 °C, respectively, were obtained using a simple current collection method with wet H2 fuel. Impedance analysis indicated that the SOFC has a potential to be improved by optimizing the current collection method. Bundle concept using the SOFCs with the packing density of 100 cells in 1 cm3 was also proposed.