Electrochemical Performance of the Ni-Fe Based Metal-Support Solid Oxide Fuel Cell with Ba-Sr-Co-Fe-O and La-Sr-Mn-O Cathodes

Unlike conventional solid oxide fuel cells (SOFCs) where ceramic materials have been used as a support, in this study a new SOFC structure with a metal support and a contact layer between the support and anode is suggested. A mixture of Ni-Fe alloy and zirconia ceramics as the contact layer were employed to enhance the compatibility of the metal support and the anode (Ni-zirconia). Common materials, including acceptor-doped zirconia and perovskites (Ba-Sr-Co-Fo-O, La-Sr-Mn-O), were used for the solid electrolyte and cathode of the SOFC. The electrode polarization resistance of the metal-supported SOFC manufactured in this way depended on the resistance between the cathode and electrolyte. For the SOFC with a Ba-Sr-Co-Fe-O cathode, not only large polarization resistance but also large ohmic resistance occurred due to the formation of an insulator phase on the surface of the solid electrolyte. Consequently, it exhibited low fuel cell performance (power density ~ 40 mW/cm2 at 750oC). On the other hand, a high fuel cell performance of ~ 290 mW/cm2 was achieved for the SOFC with the La-Sr-Mn-O cathode. The ohmic resistance was affected by the metal support and the contact layer.