Journal of Power Sources, Vol.196, No.20, 8435-8443, 2011
Glass-containing composite cathode contact materials for solid oxide fuel cells
The feasibility of adding glass to conventional SOFC cathode contact materials in order to improve bonding to adjacent materials in the cell stack is assessed. A variety of candidate glass compositions are added to LSM and SSC. The important properties of the resulting composites, including conductivity, sintering behavior, coefficient of thermal expansion, and adhesion to LSCF and Mn1.5Co1.5O4-coated 441 stainless steel are used as screening parameters. Adhesion of LSM to LSCF improved from 3.9 to 5.3 MPa upon addition of SCZ-8 glass. Adhesion of LSM to coated stainless steel improved from 1.8 to 3.9 MPa upon addition of Schott GM31107 glass. The most promising cathode contact material/glass composites are coated onto Mn1.5Co1.5O4-coated 441 stainless steel substrates and subjected to area-specific resistance testing at 800 degrees C. In all cases, area-specific resistance is found to be in the range 2.5-7.5 mOhm cm(2) and therefore acceptable. Indeed, addition of glass is found to improve bonding of the cathode contact material layer without sacrificing acceptable conductivity. (C) 2011 Elsevier B.V. All rights reserved.