Fabrication and evaluation of stable micro tubular solid oxide fuel cells with BZCY-BZY bi-layer proton conducting electrolytes

Anode-supported proton conducting micro tubular solid oxide fuel cells (MT-SOFCs) with the configuration of Ni–BaZr0.1Ce0.7Y0.2O3-δ (BZCY)/BZCY/BaZr0.8Y0.2O3-δ (BZY)/La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF)-BZY have been prepared by a combination of phase inversion method and suspension-coating technique. The obtained Ni-BZCY anode hollow fiber presents a special asymmetrical structure consisting of a sponge-like layer and a finger-like porous layer, which is propitious to anode electrochemical process. Bi-layer electrolytes consisting of 5 μm thick BZCY and 3 μm thick BZY are successfully fabricated by suspension-coating technique. BZY electrolytes are placed at the cathode side, in order to improve the chemical stability against CO2. The considerable electrochemical performance and good stability in the presence of CO2 indicate that the construction of BZY-BZCY bi-layer electrolytes is an effective way for the development of stable proton conducting MT-SOFCs.