Electrophoretic deposition of (Mn,Co)3O4 spinel coating for solid oxide fuel cell interconnects

• Published in: Journal of power sources 2011-10, Vol.196 (19), p.8041-8047
• Main Authors: Zhang, Hui, Zhan, Zhaolin, Liu, Xingbo
• Format: Article
• Language: English
• Subjects: (Mn,Co)3O4 spinel; Applied sciences; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Electrophoretic deposition; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells; Interconnect; Solid oxide fuel cell
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2011.05.053

► For the spinel coatings generated using smaller voltage than 400V, the interconnect surfaces exhibit good packing behavior and high conductivity. ► The reduced atmosphere during sintering has a beneficial impact on the minimizing chromia subscale formation and thus reducing the area specific resistance (ASR) of the coated interconnects. ► A more stable long-term performance is achieved for the spinel coating sintered in H2/H2O atmosphere with thin chromia sub-scale and no Cr penetration. ► Based on the current results, EPD followed by reduced-atmosphere sintering is a fast and economic way to deposit (Mn,Co)3O4 coating for SOFC interconnect applications. We discuss here our attempt to develop (Mn,Co)3O4 spinel coatings on the surface of Cr-containing steel through electrophoretic deposition (EPD) followed by reduced-atmosphere sintering for solid oxide fuel cell (SOFC) interconnect application. The effects of EPD voltages and sintering atmospheres on the microstructure, electrical conductivity and long-term stability of the coated interconnects are examined by means of scanning electron microscopy (SEM), energy dispersion spectrometry (EDS), X-ray photoelectron spectroscopy (XPS), and four-probe resistance techniques. For the spinel coatings generated using smaller voltage than 400V, the interconnect surfaces exhibit good packing behavior and high conductivity. The reduced atmosphere during sintering has a beneficial impact on the minimizing chromia subscale formation and thus reducing the area specific resistance (ASR) of the coated interconnects. Moreover, it is interesting to note that a more stable long-term performance is achieved for the spinel coating sintered in H2/H2O atmosphere with thin chromia sub-scale and no Cr penetration. Based on the current results, EPD followed by reduced-atmosphere sintering is a fast and economic way to deposit (Mn,Co)3O4 coating for SOFC interconnect applications.