The use of doped ceria as an interlayer in solid oxide fuel cells (SOFCs) is ubiquitous, which provides better thermal expansion match and prevents interaction between the cathode (e.g. LSCF) and electrolyte (e.g. YSZ). However, the role of ceria interlayer on the cathode phase durability and catalytic activity remains obscure. This is particularly true in nickelate cathodes (e.g. Pr2NiO4). Here, we report that traditional Gd-doped ceria (GDC) interlayer substantially accelerates the phase transition in Pr2NiO4. Two new interlayer designs were investigated in order to circuvent the phase evolution by using (1) a thin Pr6O11 film deposited on the surface of GDC, and (2) a Pr-doped ceria interlayer. The latter design not only suppresses the phase transition, but also results in a 48% increase in cathode performance; and more importantly, it leads to a zero degradation over long-term measurements. Systemetic in situ and post analyses were carried out to understand the mechanism, by which the interlayer affects the cathode durability and activity.

This material is based upon work supported by the U.S. Department of Energy under Award Number DE-FE0023475.