Ce(Mn,Fe)O2 as An Effective Interlayer for Intermediate Temperature SOFCs Using Doped LaGaO3 Films Prepared by Screen Printing Method

Abstract

Effects of a reactive interlayer, such as Mn- and Fe-doped ceria (CMF), were investigated on the electrochemical performance of a cell using Sr- and Mg-doped LaGaO3 (LSGM) electrolyte film compared to that of an inert one, La-doped ceria added with titania (Ti-LDC). Three anode supported cells were prepared using a Ti-LDC (A-Cell), a CMF (B-Cell), and an interlayer consisting of CMF/Ti-LDC layers (C-Cell), respectively, with LSGM films by screen printing and co-sintering at 1623 K. The C-Cell revealed an OCV higher than 1.12 V and a cell performance higher than that of other cells at 773–973 K because of the reduced ohmic and polarization resistances. The decreased ohmic resistance was attributed to the high ionic conductivity of CMF compared with that of Ti-LDC, decrease in the contact resistance for intimate contact at the anode interface, and suppressed Ni diffusion into the electrolyte. Decrease in the polarization resistance was attributed to the formation of Ni-Fe bimetals by the reactivity of the anode and CMF as well as to the high electro-catalytic activity of CMF for the anode reaction. Thus, a reactive CMF interlayer is promising for increasing the power generation property of a cell using LSGM electrolyte film.