Microstructure and electrical property of composite Co-W/CuO multilayered oxide coating for solid oxide fuel cell interconnector

作者：Lei, Yunong; Tang, Guojun; Shi, Zhenyu; Gu, Huazhi; Gan, Lu^*

来源：Surfaces and Interfaces, 2024, 44: 103673.

DOI：10.1016/j.surfin.2023.103673

• SOFC interconnector
• Composite electroplating
• Co-W alloy
• Area specific resistance

To overcome the challenges related to the electrical resistance owing to the growth of the Cr-containing oxide layer in the SOFC system at high temperature, a composite coating of Co-W/CuO was fabricated on ferritic stainless steel for interconnectors by composite electroplating and pre -oxidation treatment. Compared to the CoW alloy coating, the addition of CuO led to the formation of Cu -Co spinels and Cu -W composites, which affected the surface microstructure of the coating. Scanning electron microscopy with energy -dispersive spectroscopy (SEM-EDS) and transmission electron microscopy (TEM) investigations shows that CuWO4 nano -particles formed in the Cr-rich layer beneath the CoWO4 layer, of which the lattice deviation leads to the formation of oxygen vacancies. The CuWO4 acted as conductive pathways, reducing the electrical resistance. Long-term oxidation exposure further demonstrated that the Co-W/CuO coated SUS 430 exhibited a stable electrical conductivity of 10.23 m omega cm2.