Slip Casting and Solid-State Reactive Sintering of BCZY(BaCexZr0.9-xY0.1O3-d)-NiO/BCZY Half-Cells

Sandrine Ricote; Robert J Kee; William G Coors

doi:10.3390/membranes12020242

Slip Casting and Solid-State Reactive Sintering of BCZY(BaCe_xZr_0.9-xY_0.1O_3-d)-NiO/BCZY Half-Cells

Membranes (Basel). 2022 Feb 19;12(2):242. doi: 10.3390/membranes12020242.

Authors

Sandrine Ricote¹, Robert J Kee¹, William G Coors²

Affiliations

¹ Mechanical Engineering Department, Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401, USA.
² Hydrogen Helix, Golden, CO 80401, USA.

Abstract

Slip casting was used to prepare BaCe_xZr_0.9-xY_0.1O_3-d(BCZY)-NiO tubes with a diameter of ½ inches (1.25 cm) and ¾ inches (1.875 cm). Two compositions were studied: BCZY18 and BCZY27 for x = 0.1 and 0.2, respectively. The unfired tubes were then dip-coated with three layers of the BCZY electrolyte membrane. Solid-state reactive sintering was used, meaning that the support and membrane were prepared with the precursors (oxides and carbonates). After co-sintering at 1550 °C, a 20-micron thick dense BCZY layer was well-adhered to the 1 mm thick BCZY-NiO support, as confirmed by scanning electron microscopy. The sintered BCZY-NiO/BCZY tubes were sealed onto alumina or BCZY substrates using a silver-based braze (with TiO₂ and CuO additions). Gas tightness was achieved under 2 bar when covering the silver braze with a ceramic (Resbond) sealing layer. These slip cast tubes are intended for use as hydrogen electrodes in various protonic ceramic devices, and the advantages of short tubes for reactor design are discussed.

Keywords: BCZY; brazing; protonic ceramic; slip casting; solid-state reactive sintering.