Diffusion Processes Between the Barrier Cathodic Layer and the Electrolyte of a Solid-Oxide Fuel Cell

We study the influence of reducing and oxidizing media on the mutual diffusion of chemical elements between the (Ce,Gd)O 2–δ barrier (protective) cathodic layer and the YSZ electrolyte of a solid-oxide fuel cell in the course of annealing at 1400°С. The results of the analysis of distributions of chemical elements in annealed specimens demonstrate that, in the case of annealing in the reducing medium, the diffusion of Ce and Gd into the electrolyte is more intense than the diffusion of Zr from the electrolyte into the protective layer. As compared with the oxidizing medium (air), the mutual diffusion of Ce, Gd, and Zr in the reducing (hydrogen-containing) medium is much more intense and the depth of their penetration is 1.5–3 times larger.