Electrophoretic Deposition as Preparation Method for Intermediate Temperature SOFC Half Cells

Abstract

In this study we present the preparation of SOFC half cells by electrophoretic deposition. The cathode is deposited from a methyl ethyl ketone (MEK) suspension on dense apatite type lanthanum silicate (ATLS) pellets using a constant voltage. ATLS are a new class of electrolytes, which provides good oxygen permeability even at temperatures below 800°C. As cathode materials we used La2Ni0.8Cu0.2O4+δ (LNC) and La0.8Sr0.2Ni0.6Fe0.4O3 (LSNF). A conductive layer on the ATLS material was used to provide the necessary conductivity for electrophoretic deposition (EPD) process. For the preparation of suitable suspensions the charging behaviour and particle size of the different powders were investigated by means of zeta-potential and laser scattering measurements. When the electrophoretic mobility of the suspended particles was not sufficient iodine was added. Deposition kinetics were determined prior to preparation of the half cells. EPD parameters as well as sintering conditions were optimized in order to gain well adhering porous cathode layers.