Formation of Thin-Film Electrolyte by Electrophoretic Deposition onto Modified Multilayer Cathode

Abstract

Possibility of forming a gas-tight thin-film solid electrolyte by the electrophoretic deposition method on a modified multilayer cathode was examined. The main goal of the study was to find such technological parameters at which the resulting structure of the cathode substrate would make it possible to preserve its porous structure and functional properties after all the stages of deposition and sintering of a defect-free thin-film electrolyte. The electrode materials LaNi_0.6Fe_0.4O_3−δ (LNFO) and La₂NiO_4+δ (LNO), used to form the electrode-substrate, were produced by the modified Pechini method and the ceramic method. The influence exerted by the specific surface area of the starting LNFO powders, introduction of a pore-forming agent (graphite), and sintering temperature of the cathode substrate on its porosity, gas tightness, and electrical conductivity was examined. The method of cyclic electrophoretic deposition with intermittent calcination stages on a multilayer porous cathode substrate constituted by a 1-mm-thick collector LNFO layer with a deposited functional LNO layer (3–5 µm) was used to form a defect-free thin-film solid electrolyte Ce_0.8(Sm_0.8Sr_0.2)_0.2O_2−δ (CSSO) (thickness 5 µm, gas-tightness coefficient 0 µm²). A test sample of the cathode substrate preserved its porous structure and gas tightness after calcination cycles. The results obtained can be used to develop a technology for formation of a thin-film electrolyte on porous multilayer cathode substrate, with their porous structure preserved.