Thermal inkjet printing of thin-film electrolytes and buffering layers for solid oxide fuel cells with improved performance

In this study, we report the facile fabrication of thin-film yttria-stabilized zirconia (YSZ) electrolytes and Sm_0.2Ce _0.8O_1.9 (SDC) buffering layers for solid oxide fuel cells (SOFCs) using a thermal inkjet printing technique. Stable YSZ and SDC inks with solids contents as high as 20 and 10 wt.%, respectively, were first prepared. One single printing typically resulted in an YSZ membrane with thickness of approximately 1.5 μm, and membranes with thicknesses varied from 1.5 to 7.5 μm were fabricated with multiple sequential printing. An as-fabricated cell with a La_0.8Sr_0.2MnO₃ (LSM) cathode delivered a peak power density (PPD) of 860 mW cm^-2 at 800 C. The SDC layer prepared using the inkjet printing method exhibited enclosed pores and a rough surface, which was, however, ideal for its application as a buffering layer. A cell with a dense 7.5-μm-thick YSZ layer, a 2-μm-thick SDC buffering layer and a Ba_0.5Sr_0.5Co_0.8Fe_0.2O _3-δ (BSCF) cathode was fabricated; this cell delivered a PPD of 1040 mW cm^-2 at 750 C and a high open circuit voltage (OCV) of approximately 1.10 V. The described technique provides a facile method for the fabrication of electrolytes for SOFCs with precise thickness control.