Low-Cost Plasma Spray Coating for Solid Oxide Fuel Cell Balance of Plant Components

Solid oxide fuel cells SOFCs) represent the cleanest, most efficient and versatile chemical-to-electrical energy conversion system being developed today. A critical challenge in the commercialization of SOFCs is to develop a low cost solution to the problem of chromium contamination of the cathode from the chromium Cr) containing stainless steel components within the balance of plant BOP) components such as air feed and heat exchanger system. The solution must be capable of withstanding an operating environment of 900oC and be stable in the presence of atmospheric humidity while preventing emission of chromium vapors from Cr-containing steel components. In this project, HiFunda will develop and demonstrate an innovative plasma spray process for applying low cost durable ceramic coatings to low cost steel parts used in SOFC BOP components to enhance their performance in operating conditions, and reduce the lifetime cost of these components. In the Phase I project, compositions that have adequate thermal expansion compatibility with typical stainless steels used in SOFC BOP components will be developed. Processing parameters that can produce dense, thin ceramic coatings of these down-selected compositions will be identified and applied on low cost stainless steel substrates, and the chromium vaporization at elevated temperatures will be measured. Finally, cost models will be developed for a variety of production scale levels to assess the cost savings potential of the proposed coating system.. The coatings developed through this project can be used to significantly enhance the reliability of stainless steel components used in SOFC BOP components, and ultimately enable greater adoption of SOFC technology for utility scale power generation. In particular, the new technology is expected to reduce degradation rates of SOFC systems and can help to meet DOE target requirements of 40,000 hours of service for stationary fuel cell applications and greater than 5,000 hours for transportation systems fuel cell vehicles), while meeting cost targets of $400/kW. SOFCs, especially in CHP applications, can have very high combined thermal and electrical efficiencies over 80%). In addition, the coating technology developed will also find applications in a number of other areas where high temperature hot corrosion of steel is problematic including conventional coal and natural gas based power generation.