Non-aqueous stabilized suspensions of BaZr0.85Y0.15O3−δ proton conducting electrolyte powders for thin film preparation

• Published in: Journal of the European Ceramic Society 2013-09, Vol.33 (10), p.1833-1840
• Main Authors: Dias, Paulo A.N., Nasani, Narendar, Horozov, Tommy S., Fagg, Duncan P.
• Format: Article
• Language: English
• Subjects: Ceramics; Electrolytes; Ethyl alcohol; Nickel; Proton ceramic fuel cell (PCFC); Sedimentation; Spin coating; Surfactants; Suspensions stabilization; Thin films; Yttrium doped barium zirconate
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2013.02.030

The development of uniform electrolyte thin films minimizes the ohmic loss of ceramic oxide electrolyzers and/or fuel cells, increasing their efficiency. In this work, thin films of BaZr0.85Y0.15O3−δ (BZY) electrolyte have been obtained over a 40vol% Nickel–BaZr0.85Y0.15O3−δ (Ni–BZY) cermet anode support by spin coating. To facilitate this aim, stable suspensions have been tailored, by methodically determining suitable solvents and additives (surfactants and/or thickeners). Sedimentation studies showed that ethanol and 1-methoxy-2-propanol can produce similar, stable 5% w/w BZY suspensions. The best result was obtained by simultaneously adding 1.5wt% of ZEPHRYM PD 7000 (a commercial polyoxyalkylene amine derivative surfactant) and 0.3wt% of polyvinyl butyral (PVB) in 1-methoxy-2-propanol. Suspensions of 1-methoxy-2-propanol with higher powder concentration (25% w/w) also show good stability that was improved by the addition of 1wt% of ZEPHRYM. Using this system, dense BZY films of around 14μm thick could be successfully obtained at 1500°C.