Cu and Y doped (Co, Mn)3O4 spinel coatings on Crofer ferritic alloy by composite electrodeposition

Abstract

Metallic and reactive elements doped (Co,Mn)3O4 (CMO) spinel has been considered as the most promising coating to protect the ferritic alloys which are applied as the metallic interconnect of solid oxide fuel cells (SOFCs). In this study, the (Co,Mn)3O4 doped with Cu and Y ((Co,Mn,Cu,Y)3O4, CMCuY in abbreviation) spinel coatings are synthesized on the Crofer ferritic alloy by composite electrodeposition and subsequent heat-treatment process. The double-doped CMCuY spinel coating improves the sintering characteristics, as well as electrical conductivity and oxidation resistance of the alloy. The area-specific resistance (ASR) of the obtained CMCuY spinel coating is 5.89 mΩ cm2 at 800 °C after 500 h oxidation, which is much lower than the CMO spinel (34.36 mΩ cm2) and the Crofer substrate (43.2 mΩ cm2). Besides, the CMCuY spinel coating can control the Cr6+/Crtotal ratio at about 25% after 500 h of oxidation, thereby acts as an effective barrier to the Cr evaporation from the matrix effectually. In addition, this work provides a simple and effective way to prepare the Cu and Y doped (Co, Mn)3O4 spinel coatings on the ferritic alloy, which applies to the fabrication of other doped spinel coatings and helps to accelerate its industrial application in the SOFCs.