Comparative Study of Electrophoretic Deposition of Doped BaCeO₃-Based Films on La₂NiO_4+δ and La_1.7Ba_0.3NiO_4+δ Cathode...

This paper presents the results of a comparative study of methods to prevent the loss of barium during the formation of thin-film proton-conducting electrolyte BaCe_0.89Gd_0.1Cu_0.01O_3-δ (BCGCuO) on La₂NiO_4+δ-based (LNO) cathode substrates by electrophoretic deposition (EPD). Three different methods of the BCGCuO film coating were considered: the formation of the BCGCuO electrolyte film without (1) and with a protective BaCeO₃ (BCO) film (2) on the LNO electrode substrate and the formation of the BCGCuO electrolyte film on a modified La_1.7Ba_0.3NiO_4+δ (LBNO) cathode substrate (3). After the cyclic EPD in six stages, the resulting BCGCuO film (6 μm) (1) on the LNO substrate was completely dense, but the scanning electron microscope (SEM) analysis revealed the absence of barium in the film caused by its intensive diffusion into the substrate and evaporation during the sintering. The BCO layer prevented the barium loss in the BCGCuO film (2); however, the protective film possessed a porous island structure, which resulted in the deterioration of the film's conductivity. The use of the modified LBNO cathode also effectively prevented the loss of barium in the BCGCuO film (3). A BCGCuO film whose conductivity behavior most closely resembled that of the compacts was obtained by using this method which has strong potential for practical applications in solid oxide fuel cell (SOFC) technology.