Multi-Layer Processed 50×50mm2 Cathode-Supported Thin-Film Proton Conducting Electrolysis Cells Via Inverse Tape Casting

Abstract

Despite progress made with small scale laboratory type solid oxide proton-conducting electrolysis cells in recent years, a significant challenge has been upscaling robust and affordable planar type devices. The fabrication of such multilayered devices, usually via a tape casting process requires careful control of shrinkages of individual layers to prevent warping and cracks during sintering. In the present contribution, 5 × 5 cm2 planar cathode-supported protonic electrolysis half-cell consisting of Ba(Zr0.5Ce0.4)8/9Y0.2O2.9 electrolyte, NiO-SrZr0.5Ce0.4Y0.1O3-δ cathode functional layer and NiO-Ba(Zr0.5Ce0.4)8/9Y0.2O2.9 substrate were successfully processed using an inverse tape casting route. The sintering parameters of the half-cells were analyzed and adjusted to obtain defect-free half-cells with diminished warping. The smooth tri-layered green tapes produced yielded suitably dense and gas-tight electrolyte layers after co-sintering at 1350 ºC/5h. The low sintering behavior of the green tapes, as well as the obtained final microstructure, are direct results of careful control over some casting parameters. For example, slurry viscosities, thicknesses of individual layers, temperature, and time scheme for firing. Current-voltage characteristics and hydrogen evolution rates measured in the temperature range 500-600°C, using Ba0.5La0.5CoO3−δ as the anode, demonstrate excellent performance and durability. Cross-sectional view of the polished layered structured BZCY(54)8/92 complete cell post cell characterization were also analyzed. Preliminary results revealed well-adhered layers and delamination free even after steam electrolysis testing.AcknowledgmentsThis work was supported by the JSPS Core-to-Core Program of Advanced Research Networks (Solid Oxide Interfaces for Faster Ion Transport), the Ministry of Economy, Trade, and Industry (METI), Grants-in-Aid for Scientific Research (KAKENHI), DAICHI and by the International Institute for Carbon-Neutral Energy Research (I2CNER) sponsored by the World Premier International Research Center Initiative (WPI), MEXT Japan.