Development of metal supported solid oxide fuel cells based on powder metallurgical manufacturing route

Abstract

In the past few decades, stationary solid oxide fuel cell (SOFC) systems have been developed that can generate electricity and heat from the energy stored in hydrogen or hydrocarbons with total efficiencies up to 95%. While the mechanical cell support of stationary systems is commonly supplied by thick ceramic cell components (i.e. anode and electrolyte supported concepts), mobile systems demand a more robust design. This is ensured by a strong yet porous metallic substrate which serves as the mechanical backbone of thin film membrane electrode assemblies [metal supported cell (MSC) concept]. Porous PM Fe-Cr oxide dispersion strengthened alloys for use as MSC supports have recently been developed. These materials provide mechanical and chemical long term stability in typical SOFC atmospheres at operation temperatures up to 850°C. The substrates support a multilayer anode-electrolyte-cathode thin film assembly, constituting a high performance MSC repeat unit. These units are the building blocks for MSC stacks with superior properties for mobile applications

What Will Be the Future of Powder Metallurgy?

“…For medium voltage vacuum switches, Cu-Cr contacts are used which can also be produced by ingot metallurgy routes; here, however, the shaping capability of PM is a distinct advantage for manufacturing the very complex contact ends of these switches. Another application for PM refractory metals and superalloys are components for solid oxide fuel cells [22], the metal-based SOFCs being more robust mechanically than e.g. anode or electrolyte-supported variants.…”

Model System Supported Impedance Simulation of Composite Electrodes

“…For all three cases, a deeper fundamental understanding of the electrochemical processes and the reaction kinetics of the fuel electrodes is needed to increase the power density and long term stability of SOCs thus enabling them to commercially compete with existing systems such as combustion engines. In this context, the following issues have to be addressed: (i) for stationary SOFC applications, H 2 S induced performance losses of the fuel electrode need to be minimized to reach cell lifetimes above 40,000 h , , , (ii) in case of metal‐supported SOFCs – due to the sintering process in reducing environment – the anode suffers from a suboptimal microstructure, which constitutes an obstacle on the way to higher power densities , , , , (iii) running Ni/YSZ fuel electrodes in electrolysis mode makes them prone to microstructural changes, which leads to an electrochemical performance loss of SOECs , . To develop efficient counter strategies for the electrode‐related performance issues the complex interplay of electrochemical elementary processes and the microstructure of the fuel electrode needs to be well‐understood.…”

High-Performance Metal-Supported Solid Oxide Fuel Cells by Advanced Cathode Processing

“…Ar(5.0) for simulating sintering in inert atmosphere, Ar/2.9%H 2 for simulating harsh conditions, which might occur in the case of very pronounced oxygen-getter effect of a porous metal with large surface area. Thermal treatment of the samples was carried out at temperatures in the range of 850 to 1040 • C. These temperatures represent the prevalent conditions during thermal treatment in either the in situ activation of state-of-the-art MSCs 33,50 or the established sintering procedure of ASCs with a PVD-GDC barrier layer. 36 The experiments were conducted in a tube furnace (Al 2 O 3 tube, heated length 750 mm, diameter 80 mm).…”