Effect of Coatings on a Commercial Stainless Steel for SOEC Interconnect Application in Anode Atmosphere

摘要

The high temperature steam electrolysis (HTE) represents one of the most promising technologies for mass hydrogen production. A commercial K41X steel (AISI441) containing 18 wt.% of chromium was tested as interconnect for solid oxide electrolyser cells (SOEC). In a previous paper, it was shown that the uncoated alloy is not suitable for SOEC interconnect application at 800°C in O_2-H_2O atmosphere. It was also proved that the application of a LaNi_(0.6)Fe_(0.4)O_(3-δ) coating on the surface by physical vapour deposition process improves the alloy electrical behaviour and reduces chromium species evaporation. For this study, the same coating was deposited on the alloy surface by screen-printing process. Moreover, two spinel-type oxides, Co_2MnO_4 and Co_3O_4, deposited by physical vapour deposition process, were also tested in O_2-H_2O atmosphere at 800°C. The electrical conductivity did not present any improvement, but the Cr species volatility was reduced, especially with the LaNi_(0.6)Fe_(0.4)O_(3-δ) coating.