Recent developments in metal-supported solid oxide fuel cells

Metal-supported solid oxide fuel cells (MSCs) offer certain strategic advantages over the more conventional solid oxide fuel cells (SOFCs), which comprise only ceramic materials. Since alloys such as ferritic steels are very similar in their coefficient of thermal expansion (CTE) with ceramic components, viz., cerias, zirconias, and nickel oxide doped with either of them, they could provide excellent thermal cyclability while maintaining a strong interlayer bond. Therefore, in an anode-supported cell the entire NiO-ceramic support can be replaced by a ferritic steel porous support-the catalytically active NiO is therefore, a functional layer only. A huge savings in materials cost is achievable, because cerias and zirconias [usually doped with Y, Gd, Sm rare earth (RE) elements] are considerably more expensive that ferritic steels. Lowering the capital costs for SOFCs is an extensive global undertaking with US Department of Energy (DOE) laying down targets such as similar to$ 200/kW for the stack itself, in order for SOFCs to become competitive with grid power costs and to offer a power source that promises 24 x 7 power supply for critical applications. This will eventually lead to a premier electricity generation device in the distributed power space, with the highest known electrical efficiencies (>50%). MSCs need very robust, high precision, and cost-effective manufacturing techniques, which are scalable to high volumes. One of the main goals in this review is to showcase some of the work done in this area since the last review (2010), and to assess the technology challenges, and new solutions that have emerged over the past few years. (C) 2017 John Wiley & Sons, Ltd