Publikationsdatum:
2019
Beschreibung:
Abstract
Freeze casting is an established method for fabricating porous ceramic structures with controlled porosity and pore geometries. Herein, we developed a novel freeze casting and freeze drying process to fabricate tubular anode supports for solid oxide fuel cells (SOFCs). Freeze casting was performed by injecting aqueous anode slurry to a dual‐purpose freeze casting and freeze drying mold wrapped with peripheral coils for flowing a coolant. With the use of an ice barrier layer, proper control of the experimental setup, and adjustments in the drying temperature profile, complete drying of the individual anode tubes was achieved in four hours. The freeze‐cast anode tubes contained radially aligned columnar pore channels, thus significantly enhancing the gaseous diffusion. SOFC single cells with conventional Ni/yttria‐stabilized zirconia (YSZ)/strontium‐doped lanthanum manganite (LSM) materials were prepared by dip coating the thin functional layers onto the anode support. Single‐cell tests showed that the concentration polarization was low owing to the highly porous anode support with directional pores. With H2/N2 (1:1) fuel, maximum power densities of 0.47, 0.36, and 0.27 W/cm2 were recorded at 800, 750, and 700 °C, respectively. Our results demonstrate the feasibility of using freeze casting to obtain tubular SOFCs with desired microstructures and fast turn‐around times.
This article is protected by copyright. All rights reserved.
Print ISSN:
0002-7820
Digitale ISSN:
1551-2916
Thema:
Maschinenbau
,
Physik
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