Research on Performance of LSM Coating on Interconnect Materials for SOFCs

Experiments were conducted using SUS430 and Crofer 22 APU steels coated by LSM using plasma spray and slurry spray methods, respectively. High-temperature conductivity and oxidation resistance were investigated. For comparison, SUS430 and Crofer 22 APU without LSM coating were also investigated and coefficient of thermal expansion (CTE) was measured. The results show that the materials without LSM coating exhibit almost the same CTE as YSZ electrolyte in a range of temperatures of 550 similar to 850 degrees C. When coated with LSM, the oxidation rate of the steels decreases by 30 similar to 40% using slurry spray and by 10 similar to 30% using plasma spray whereas the steels using plasma spray have a better bigh-temperature conductivity than the steels using slurry spray. It is thus concluded that the LSM coating has a limited effect on increasing high-temperature conductivity while it can effectively reduce the oxidation of the steels.