Anodes

Anodes form the surface upon which fuel oxidation takes place with the cell, as such, correct design and materials selection are vital for high performance and long term durability. This becomes even more critical where hydrocarbon or other more complex fuels are considered, as tolerance to carbon and other potential impurities are vital in the realisation of a robust electrode for these environments. This chapter starts by defining the performance criteria for an SOFC anode followed by discussion of the lifetime requirements and catalysis demands for different fuels. The advantages and disadvantages of the state of the art engineering designs and materials (i.e Ni/YSZ cermets) are then covered.Newer alternative electrode materials are then introduced, initially cermets based on other metals, such as Cu. Thereafter, the chapter continues with the newer all ceramic oxide anode, typically perovskite materials based on transition metals such as: La0.75Sr0.25Cr0.5Mn0.5O3 (LSCM) or doped SrTiO3. These can be used either by themselves or as composites with electrolyte materials. The chapter concludes with sections on modifying the anodes via impregnation and ex solution to improve performance and lower cost.