In:
ECS Meeting Abstracts, The Electrochemical Society, Vol. MA2015-02, No. 36 ( 2015-07-07), p. 1264-1264
Abstract:
Acceptor-doped barium zirconate electrolytes, represented as yttrium-doped barium zirconate (Y:BaZrO 3 or BZY), are expected to allow ceramic fuel cells to be operated at intermediate temperatures in the range below 600 °C. This is because BZY conducts protons and exhibits a relatively high ionic conductivity with relatively small activation energy, especially compared to ceramics that conduct oxide ions, including yttria-stabilized zirconia (YSZ) and gadolinia-doped ceria (GDC). The bulk conductivity of BZY is greater than that of YSZ by about one order at 600 °C and by two orders at 400 °C and, unlike cerate-based materials, BZY was found to exhibit good phase stability (1). Thus, there have been numerous efforts to develop BZY-based protonic ceramic fuel cells (BZY-PCFCs). Although several studies have reported BZY-PCFCs to perform well, with outputs of 140 mW/cm 2 and 180 mW/cm 2 in the intermediate temperature regime at 400 °C (2) and 450 °C (3), respectively, both of these were achieved in the form of freestanding nanoscale membranes. For practical production and use, however, fabrication of the BZY electrolyte in anode-supported stacks would be more desirable. Yet, the performance of anode-supported BZY-PCFCs is not yet as good as that of solid-oxide fuel cells. To our knowledge, 170 W/cm 2 is the greatest power output achieved with BZY-based fuel cells at 600 °C (4). An attempt to adopt a thin BZY electrolyte (4μm thickness) in anode-supported PCFCs has produced a power output of merely 110 W/cm 2 at 600 °C (5), attributed to the prevalence of a relatively large ohmic resistance, which implies the presence of structural defects such as poor grain adhesion (5). After performing a series of experiments, we realized that the adoption of multiple anode support layers with multi-step sintering promotes the structural and mechanical stability of thin film BZY electrolytes. As a result, the power output has exceeded 700 mW/cm 2 at 600 °C with an open circuit voltage over 1 V. At this presentation, we will share our recent experimental results and discuss the cell performance in relation with structural characteristics and composition. 1. K. D. Kreuer, Annu. Rev. Mater. Res. , 33 , 333 (2003). 2. J. H. Shim, J. S. Park, J. An, S. Kang, T. M. Gür, and F. B. Prinz, Chem. Mater. , 21 (14), 3290 (2009). 3. Y. B. Kim, T. M. Gür, S. Kang, H-J. Jung, R. Sinclair, and F. B. Prinz, Electrochem. Commun. , 13 (5), 403 (2011). 4. L. Bi , E. Fabbri , Z. Sun, and E. Traversa, Energy Environ. Sci. , 4 , 409 (2011). 5. D. Pergolesi, E. Fabbri, and E. Traversa, Electrochem . Commun. , 12 , 977 (2010).
Type of Medium:
Online Resource
ISSN:
2151-2043
DOI:
10.1149/MA2015-02/36/1264
Language:
Unknown
Publisher:
The Electrochemical Society
Publication Date:
2015
detail.hit.zdb_id:
2438749-6
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