Selection of cathode contact materials for solid oxide fuel cells

The goal of this work is to identify suitable cathode contact materials (CCM) to bond and electrically connect LSCF cathode to Mn_1.5Co_1.5O₄-coated 441 stainless steel after sintering at the relatively low temperature of 900–1000 °C. A wide variety of CCM candidates are synthesized and characterized. For each, the conductivity, coefficient of thermal expansion, sintering behavior, and tendency to react with LSCF or Mn_1.5Co_1.5O₄ are determined. From this screening, LSCF, LSCuF, LSC, and SSC are selected as the most promising candidates. These compositions are applied to LSCF and Mn_1.5Co_1.5O₄-coated 441 stainless steel coupons and subjected to 200 h ASR testing at 800 °C. After area-specific resistance testing, the specimens are cross-sectioned and analyzed for interdiffusion across the CCM/LSCF or CCM/Mn_1.5Co_1.5O₄ interfaces. A relatively narrow band of interdiffusion is observed.