Electrochemical behaviour and degradation of (Ni,M)/YSZ cermet electrodes (M=Co,Cu,Fe) for high temperature applications of solid electrolytes

Homogeneous powders of alternative (Ni,M)/YSZ cermets were prepared by combustion synthesis to obtain homogeneous mixtures of submicrocrystalline powders. These powders were used to prepare symmetrical cells cermet/YSZ/cermet, with porous cermet layers and a dense electrolyte. The cermets were reduced in H2, and tested as potential fuel electrodes for high temperature electrochemical applications. The best performance was found for Ni1−xCox/YSZ cermets but small fractions of Cu might also play a positive effect. Changes in capacitance suggest that this corresponds to cermets with enhanced microstructures. Lower firing conditions are probably needed to avoid the degradation of cermets containing Cu or Fe.