The investigation of Ag & LaCo0.6Ni0.4O3−δ composites as cathode contact material for intermediate temperature solid oxide fuel cells

The high interface resistance between cathodes and interconnects is a major cause for performance degradation of solid oxide fuel cells (SOFCs). Ag particles were mixed to LaCo0.6Ni0.4O3−δ (LCN) matrix which prevented the silver densification and demonstrated porosity microstructure. The composites with different Ag content were evaluated as cathode contact materials with SUS430 alloy as interconnects. The area specific resistance (ASR) of SUS430/10%Ag & LCN/SUS430 showed the optimal performance in which the ASR was 73 mΩ cm2 after 50 h at 750 °C and showed stable property in 10 thermal cycles from 200 °C to 750 °C. The excellent performance of 10%Ag & LCN is attributed to the high conductivity of silver, the stable microstructure of LCN and its good interface adhesion with the interconnect alloy. With 10%Ag & LCN as cathode contact materials, the power density of a single cell reached 0.623 W/cm2 at 750 °C and the average degradation is lower than 1% in 3 thermal cycles.