Advances in Low Temperature Coatings for Solid Oxide Fuel Cell Components

Abstract

In the development of solid-oxide fuel cells, coating technologies are essential to successful commercialization. Electrode coating technologies allow the cost-effective deposition of anode and cathodes on cell components at high volumes and high precision. Further, catalytic and corrosion resistant coatings for common steel alloys find application in gas delivery and fuel reforming components of the balance-of-plant. Such corrosion-resistant alloys are also combined with conductive and insulating oxide protective layers to making low-cost steel interconnectors corrosion-resistant at SOFC operating while maintaining low contact resistance and minimizing Cr volatilization. Many of the first generation coating technologies that have found commercial implementation were designed for cell and stack operating temperatures of 750°C and higher. By design, conductive coatings for steels provide low contributions to the overall stack resistance (ASR < 0.05 ohm-cm2) at these operating temperatures. However, as stack operating temperatures push to the 600°C range, new protective coatings are required that achieve similar resistances at lower temperatures. In this paper, Nexceris will report on the development of new formulations designed to meet these needs, based on our patented approaches. To complement these protective coatings, Nexceris has developed a suite of contact paste, insulating layer coatings and catalytic materials for SOFC stacks and balance of plant, all designed with the end-user needs in mind. Leveraging aerosol spray deposition approaches that have been scaled to commercial requirements, Nexceris can interleave these coatings to create uniquely functional interconnects, cells and reformer components. Examples of the flexibility of these coating approaches will be provided, with performance data.