Recent Progress in the Development of Anode Materials for Solid Oxide Fuel Cells

Abstract

The fi eld of research into solid oxide fuel cell (SOFC) anode materials has been rapidly moving forward. In the four years since the last in-depth review signifi cant advancements have been made in the reduction of the operating temperature and improvement of the performance of SOFCs. This progress report examines the developments in the fi eld and looks to draw conclusions and inspiration from this research. A brief introduction is given to the fi eld, followed by an overview of the principal previous materials. A detailed analysis of the developments of the last 4 years is given using a selection of the available literature, concentrating on metal-fl uorite cermets and perovskitebased materials. This is followed by a consideration of alternate fuels for use in SOFCs and their associated problems and a short discussion on the effect of synthesis method on anode performance. The concluding remarks compile the signifi cant developments in the fi eld along with a consideration of the promise of future research. The recent progress in the development of anode materials for SOFCs based on oxygen ion conducting electrolytes is reviewed.

Evolution of the electrochemical interface in high-temperature fuel cells and electrolysers

“…Other, more elaborate electrode microstructures may be used to maximise 3PB and/or 2PB regions, as shown in Figure 2l-n, by selecting dedicated materials to fulfil desired functions (Figure 2a). A more comprehensive overview of materials and microstructures used in SOCs can be found in previous reviews [1][2][3][4][5] . Figure 2.…”

“…The schematics of three proposed hydrogen electrode mechanisms (a, b, c) are shown below with d illustrating the influence of impurities. Several ceramic materials such as doped ceria and perovskite structured oxides have emerged as excellent MIEC electro-catalysts for H2 oxidation and H2O reduction, 1,5 extending the reaction to the entire ceramic/gas interface (2PB) 28 with the surface reaction being rate determining 28,29 . …”

Surface structure of coherently strained ceria ultrathin films

“…Practically, ceria and YSZ are the materials of choice for anodes and electrolytes, respectively, in real-world SOFCs [11,12]. From the fundamental perspective, the surface of uniform, quasi-two-dimensional epitaxial film with well-defined crystallographic orientation is an ideal model system to study reactions occurring on the oxide surfaces.…”

One-step synthesis and microstructure of CuO-SDC composites

“…In these cermets, Ni metal offers good electronic conductivity and catalytic activity for fuel oxidation, while the ceramic phase provides ionic conductivity, structural support, and reduces the Ni agglomeration during fuel cell operation at 800 to 1000 °C [1][2][3]. It is well known that the cermet performance depends on content, distribution and grain size of both metallic and ceramic phases, which together with the gaseous phase make up the triple phase boundaries, electrochemical sites where the fuel oxidation reactions take place [4][5][6]. Although widely used, Ni-based anodes have some disadvantages, especially the carbon deposition on the nickel surface, a poisoning phenomenon commonly observed when hydrogen fuel is replaced by hydrocarbons.…”