Performance of CoMnO Spinel Coating onto 441 SS for SOEC Interconnect Application

Abstract

In this study, CoMnO spinel was applied via atmospheric plasma spray onto 441 SS as SOEC interconnect coating. The performance of oxidation corrosion, electrical resistance, and Cr migration are evaluated. The influence rule was elucidated as the higher the plasma torch power and the thicker coating, the higher the deposition efficiency for the coated specimens. The long-term isothermal oxidation measurement was conducted under a simulated environment for 504 h. The CoMnO35 specimen had a small kp at 6.54 × 10−5 mg2 cm−4 h−1 below the CoMnO30 (7.1 × 10−5) one, and the bare steel sample (1.3 × 10−3). The area-specific resistance (ASR) depends on the temperature and time measured. The CoMnO35 specimen had a smaller Ea (0.61 eV) than the bare steel sample (0.91 eV) and CoMnO38 (0.85 eV). In addition, the CoMnO35 had a lower ASR (27.33 mΩ cm2) than the uncoated one (1.58 Ω cm2 for 670 h).