Preparation and electrochemical behavior of dense YSZ film for SOEC

High Temperature Electrolysis (HTE) through a solid oxide electrolytic cell (SOEC) had been receiving more and more attentions recently because of its high conversion efficiency (45–59%) and its potential usage for large-scale hydrogen or synthetic fuels production. One of the key technologies associated with SOEC fabrication was to prepare dense yttria-stabilized zirconia (YSZ) electrolyte film on the surface of hydrogen electrode. A novel screen-printing method was developed to fabricate gas-tight YSZ films on porous NiO-YSZ to reduce ohmic resistance of electrolytes and improve electrochemical performance of cells in this paper. The effects of pre-calcining temperature of cathodes, numbers of printing layers and sintering temperature of YSZ films were investigated in detail. SEM and EIS analyses revealed that the selected process parameters had significant influences on the microscopic morphology of YSZ electrolyte film, the OCVs and power density of the prepared cells. After optimization, a 10 μm dense YSZ film was prepared successfully on porous NiO-YSZ support with an OCV of 1.069 V and the electrolysis current density up to 0.681 A/cm2 at 1.50 V and 850 °C.

► A ceramic power method was developed to fabricate gas-tight YSZ on porous Ni/YSZ.
► Effects of process conditions were investigated in detail.
► A 10 μm dense YSZ film was prepared successfully on porous Ni/YSZ support.
► The electrolysis current density can be up to 0.681 A/cm2 at 1.50 V and 850 °C.