Asymmetric LSCF Membranes Utilizing Commercial Powders

Powders of constant morphology and quality are indispensable for reproducible ceramic manufacturing. In this study, commercially available powders were characterized regarding their microstructural properties and screened for a reproducible membrane manufacturing process, which was done by sequential tape casting. Basing on this, the slurry composition and ratio of ingredients were systematically varied in order to obtain flat, crack-free green tapes suitable for upscaling of the manufacturing process. Debinding and sintering parameters were adjusted to obtain defect-free membranes with diminished bending. The crucial parameters are the heating ramp, sintering temperature, and dwell time. The microstructure of the asymmetric membranes was investigated, leading to a support porosity of approximately 35% and a membrane layer thickness of around 20 µm. Microstructure and oxygen flux are comparable to asymmetric La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ (LSCF) membranes manufactured from custom-made powder, showing an oxygen flux of > 1 mLcm^-2min at 900 °C in air/Ar gradient.