Browse > Article
http://dx.doi.org/10.4191/kcers.2016.53.5.506

Thermal Evolution of BaO-CuO Flux as Sintering Aid for Proton Conducting Ceramic Fuel Cells  

Biswas, Mridula (High-Temperature Energy Materials Research Center, Korea Institute of Science and Technology)
Hong, Jongsup (High-Temperature Energy Materials Research Center, Korea Institute of Science and Technology)
Kim, Hyoungchul (High-Temperature Energy Materials Research Center, Korea Institute of Science and Technology)
Son, Ji-Won (High-Temperature Energy Materials Research Center, Korea Institute of Science and Technology)
Lee, Jong-Ho (High-Temperature Energy Materials Research Center, Korea Institute of Science and Technology)
Kim, Byung-Kook (High-Temperature Energy Materials Research Center, Korea Institute of Science and Technology)
Lee, Hae-Weon (High-Temperature Energy Materials Research Center, Korea Institute of Science and Technology)
Yoon, Kyung Joong (High-Temperature Energy Materials Research Center, Korea Institute of Science and Technology)
Publication Information
Journal of the Korean Ceramic Society / v.53, no.5, 2016 , pp. 506-510 More about this Journal
Abstract
The eutectic melt of BaO-CuO flux is known to be a potential sintering aid for $Ba(Zr,Y)O_3$ (BZY) electrolyte for proton-conducting ceramic fuel cells (PCFCs). A density of BZY higher than 97% of theoretical density can be achieved via sintering at $1300^{\circ}C$ for 2 h using a flux composed of 28 mol% BaO and 72 mol% CuO. In the present study, chemical and structural evolution of BaO-CuO flux throughout the sintering process was investigated. An intermediate holding step at $1100^{\circ}C$ leads to formation of various impurity compounds such as $BaCuO_{1.977}$, $Ba_{0.92}Cu_{1.06}O_{2.28}$ and $Cu_{16}O_{14.15}$, which exhibit significantly larger unit cell volumes than the matrix. The presence of such secondary compounds with large lattice mismatch can potentially lead to mechanical failure. On the other hand, direct heating to the final sintering temperature produced CuO and $Cu_2O$ as secondary phases, whose unit cell volumes are close to that of the matrix. Therefore, the final composition of the flux is strongly affected by the thermal history, and a proper sintering schedule should be used to obtain the desired properties of the final product.
Keywords
Proton conducting fuel cell; Electrolyte; Sintering aid; Flux;
Citations & Related Records
연도 인용수 순위
  • Reference
1 C. Duan, J. Tong, M. Shang, S. Nikodemski, M. Sanders, S. Ricote, A. Almansoori, and R. O'Hayre, "Readily Processed Protonic Ceramic Fuel Cells with High Performance at Low Temperatures," Science, 349 [6254] 1321-26 (2015).   DOI
2 G. Taillades, J. Dailly, M. Taillades-Jacquin, F. Mauvy, A. Essouhmi, M. Marrony, C. Lalanne, S. Fourcade, D. J. Jones, J. C. Grenier, and J. Roziere, "Intermediate Temperature Anode-Supported Fuel Cell Based on $BaCe_{0.9}Y_{0.1}O_3$ Electrolyte with Novel $Pr_2NiO_4$ Cathode," Fuel Cells, 10 [1] 166-73 (2010).   DOI
3 F. Lefebvre-Joud, G. Gauthier, and J. Mougin, "Current Status of Proton-Conducting Solid Oxide Fuel Cells Development," J. Appl. Electrochem., 39 [4] 535-43 (2009).   DOI
4 J. H. Lee, S. M. Choi, S. B. Park, K. J. Yoon, J. W. Son, H. J. Je, B. K. Kim, and H. W. Lee, "Novel Strategies to Fabricate an Anode Supported-Type Protonic Ceramic Fuel Cells (PCFCs)," pp. 905-10 in Solid Oxide Fuel Cells 13, Vol. 57, ECS Transactions. Ed. by T. Kawada and S. C. Singhal, Electrochemical Soc Inc, Pennington, 2013.
5 F. Iguchi, T. Tsurui, N. Sata, Y. Nagao, and H. Yugami, "The Relationship between Chemical Composition Distributions and Specific Grain Boundary Conductivity in Y-doped $BaZrO_3$ Proton Conductors," Solid State Ionics, 180 [6-8] 563-68 (2009).   DOI
6 S. Barison, M. Battagliarin, T. Cavallin, L. Doubova, M. Fabrizio, C. Mortalo, S. Boldrini, L. Malavasi, and R. Gerbasi, "High conductivity and chemical stability of $BaCe_{1-x-y}Zr_xY_yO_{3-{\delta}}$ Proton Conductors Prepared by a Sol-Gel Method," J. Mater. Chem., 18 [42] 5120-28 (2008).   DOI
7 W. Zhang, K. Osamura, and S. Ochiai, "Phase Diagram of the BaO-CuO Binary System," J. Am. Ceram. Soc., 73 [7] 1958-64 (1990).   DOI
8 S. M. Choi, J. H. Lee, H. An, J. Hong, H. Kim, K. J. Yoon, J. W. Son, B. K. Kim, H. W. Lee, and J. H. Lee, "Fabrication of Anode-Supported Protonic Ceramic Fuel Cell with $Ba(Zr_{0.85}Y_{0.15})O_{3-{\delta}}-Ba(Ce_{0.9}Y_{0.1})O_{3-{\delta}}$ Dual-Layer Electrolyte," Int. J. Hydrogen Energy, 39 [24] 12812-18 (2014).   DOI
9 F. Iguchi, T. Yamada, N. Sata, T. Tsurui, and H. Yugami, "The Influence of Grain Structures on the Electrical Conductivity of a $BaZr_{0.95}Y_{0.05}O_3$ Proton Conductor," Solid State Ionics, 177 [26-32] 2381-84 (2006).   DOI
10 M. Biswas, H. An, S. M. Choi, J.-W. Son, J.-H. Lee, B.-K. Kim, H.-W. Lee, and K. J. Yoon, "Low-Temperature Sintering of $Ba(Zr,Y)O_3$-based Proton Conducting Oxides Using BaO-CuO Eutectic Flux as Sintering Aid," Ceram. Int., 42 [8] 10476-81 (2016).   DOI
11 L. A. Klinkova, V. I. Nikolaichik, N. V. Barkovskii, K. V. Van, and V. K. Fedotov, "On the Structure of Melt in the $BaO-CuO_x$ (50.0 - 80.0 mol % CuO) System at $p(O_2)=21kPa$," Russ. J. Inorg. Chem., 56 [4] 513-23 (2011).   DOI
12 M. Yin, C. K. Wu, Y. B. Lou, C. Burda, J. T. Koberstein, Y. M. Zhu, and S. O'Brien, "Copper Oxide Nanocrystals," J. Am. Chem. Soc., 127 [26] 9506-11 (2005).   DOI