Tm(III)-doped d-Bi2O3 for solid - oxide fuel cells
Апстракт
The oxide ion conductors have widely been investigated because of their application in many
devices with high economical and ecological interests, such as solid oxide fuel cells (SOFC).
-Bi2O3
polymorph possesses the highest known O2–
ion conductivity, which is one to two
orders of magnitude higher than that of stabilized zirconia at corresponding temperatures [1].
At the moment, the application of this high-temperature polymorph as an electrolyte in SOFC
requires temperatures above 730 °C. However, the doping allows -Bi2O3
stabilization to room
temperature and opens the possibility for construction of SOFC that will operate at
intermediate temperatures (ca. 350 °C) [2].
As it is found that some lanthanides are suitable dopants [3], the possibility to stabilize O2–
ion
conductors related to the -Bi2O3
polymorph in the Bi2O3–Tm2O3
system was investigated. Two
starting mixtures with compositions (Bi1–xTmx
)2O3
(x = 0.04 and 0.20) were homogenized in an
agate ...mortar, heat treated at 750 °C for 3 h and then slowly furnace cooled. The samples were
characterized by XRPD, DTA and SEI techniques.
Based on XRPD, the single-phase tetragonal β-Bi2O3
was identified in the sample with x = 0.04.
Its unit cell parameters, a = 7.742(2) and c = 5.650(2) Å, well-correspond to those of undoped
β-Bi2O3
[4]. On the other hand, the cubic -Bi2O3
phase was obtained in the sample with
x = 0.20. Its unit cell parameter was greater than the value reported for Tm-doped -Bi2O3
sample with x = 0.25 [3] (5.5033(9) vs. 5.478 Å). Both values are smaller than reported for
undoped -Bi2O3
[4]. This means that the unit cell parameter of cubic -Bi2O3
decreases as
Tm-content increases and it is in accordance with Tm3+ and Bi3+ ionic radii [5].
For the sample with x = 0.04, cyclic DTA curves showed one reversible β-Bi2O3 ↔ -Bi2O3
transition with corresponding temperatures: on heating, 660 °C, and, on cooling, 600 °C.
Surprisingly, no phase transitions were observed in the sample with x = 0.20 which indicates
that the obtained -Bi2O3
is stable within the whole investigated interval, i.e., from room
temperature to 1000 °C.
Electrochemical impedance of -Bi2O3
phase was measured in the following temperature
range: 300 – 800 °C. At higher temperatures (600 – 800 °C) the conductivities are similar
(0.11 – 0.32 S cm
–1
), but with lowering temperature they rapidly decrease, and amount, for
example, 2.1·10–5
S cm–1
at 300 °C. As a consequence, two activation energies are found:
0.45(4) eV (600 – 800 °C), and 1.33(2) eV (300 – 600 °C).
References:
[1] P. Shuk, H.-D. Wiemhöfer, U. Guth, W. Göpel, M. Greenblatt, Solid State Ionics 89 (1996) 179
[2] E. D. Wachsman, K.T. Lee, Science 334 (2011) 935
[3] H. T. Cahen, T. G. M. Van Den Belt, J. H. W. De Wit, G. H. J. Broers, Solid State Ionics 1 (1980) 411
[4] H. A. Harwig, Z. anorg. allg. Chem. 444 (1978) 151
[5] R. D. Shannon, Acta Cryst. A 32 (1976) 751
Кључне речи:
Thulium / d-Bi2O3 / Oxide ion conductorsИзвор:
8 th International Conference of the Chemical Societies of the South-East European Countries, 2013, 188-Издавач:
- Univerzitet u Beogradu, Tehnološko-metalurški fakultet
Финансирање / пројекти:
- 0-3D наноструктуре за примену у електроници и обновљивим изворима енергије: синтеза, карактеризација и процесирање (RS-MESTD-Integrated and Interdisciplinary Research (IIR or III)-45007)
Институција/група
Institut za multidisciplinarna istraživanjaTY - CONF AU - Dapčevć, Aleksandra AU - Dejan, Poleti AU - Rogan, Jelena AU - Radojković, Aleksandar PY - 2013 UR - http://rimsi.imsi.bg.ac.rs/handle/123456789/2890 AB - The oxide ion conductors have widely been investigated because of their application in many devices with high economical and ecological interests, such as solid oxide fuel cells (SOFC). -Bi2O3 polymorph possesses the highest known O2– ion conductivity, which is one to two orders of magnitude higher than that of stabilized zirconia at corresponding temperatures [1]. At the moment, the application of this high-temperature polymorph as an electrolyte in SOFC requires temperatures above 730 °C. However, the doping allows -Bi2O3 stabilization to room temperature and opens the possibility for construction of SOFC that will operate at intermediate temperatures (ca. 350 °C) [2]. As it is found that some lanthanides are suitable dopants [3], the possibility to stabilize O2– ion conductors related to the -Bi2O3 polymorph in the Bi2O3–Tm2O3 system was investigated. Two starting mixtures with compositions (Bi1–xTmx )2O3 (x = 0.04 and 0.20) were homogenized in an agate mortar, heat treated at 750 °C for 3 h and then slowly furnace cooled. The samples were characterized by XRPD, DTA and SEI techniques. Based on XRPD, the single-phase tetragonal β-Bi2O3 was identified in the sample with x = 0.04. Its unit cell parameters, a = 7.742(2) and c = 5.650(2) Å, well-correspond to those of undoped β-Bi2O3 [4]. On the other hand, the cubic -Bi2O3 phase was obtained in the sample with x = 0.20. Its unit cell parameter was greater than the value reported for Tm-doped -Bi2O3 sample with x = 0.25 [3] (5.5033(9) vs. 5.478 Å). Both values are smaller than reported for undoped -Bi2O3 [4]. This means that the unit cell parameter of cubic -Bi2O3 decreases as Tm-content increases and it is in accordance with Tm3+ and Bi3+ ionic radii [5]. For the sample with x = 0.04, cyclic DTA curves showed one reversible β-Bi2O3 ↔ -Bi2O3 transition with corresponding temperatures: on heating, 660 °C, and, on cooling, 600 °C. Surprisingly, no phase transitions were observed in the sample with x = 0.20 which indicates that the obtained -Bi2O3 is stable within the whole investigated interval, i.e., from room temperature to 1000 °C. Electrochemical impedance of -Bi2O3 phase was measured in the following temperature range: 300 – 800 °C. At higher temperatures (600 – 800 °C) the conductivities are similar (0.11 – 0.32 S cm –1 ), but with lowering temperature they rapidly decrease, and amount, for example, 2.1·10–5 S cm–1 at 300 °C. As a consequence, two activation energies are found: 0.45(4) eV (600 – 800 °C), and 1.33(2) eV (300 – 600 °C). References: [1] P. Shuk, H.-D. Wiemhöfer, U. Guth, W. Göpel, M. Greenblatt, Solid State Ionics 89 (1996) 179 [2] E. D. Wachsman, K.T. Lee, Science 334 (2011) 935 [3] H. T. Cahen, T. G. M. Van Den Belt, J. H. W. De Wit, G. H. J. Broers, Solid State Ionics 1 (1980) 411 [4] H. A. Harwig, Z. anorg. allg. Chem. 444 (1978) 151 [5] R. D. Shannon, Acta Cryst. A 32 (1976) 751 PB - Univerzitet u Beogradu, Tehnološko-metalurški fakultet C3 - 8 th International Conference of the Chemical Societies of the South-East European Countries T1 - Tm(III)-doped d-Bi2O3 for solid - oxide fuel cells SP - 188 UR - https://hdl.handle.net/21.15107/rcub_rimsi_2890 ER -
@conference{ author = "Dapčevć, Aleksandra and Dejan, Poleti and Rogan, Jelena and Radojković, Aleksandar", year = "2013", abstract = "The oxide ion conductors have widely been investigated because of their application in many devices with high economical and ecological interests, such as solid oxide fuel cells (SOFC). -Bi2O3 polymorph possesses the highest known O2– ion conductivity, which is one to two orders of magnitude higher than that of stabilized zirconia at corresponding temperatures [1]. At the moment, the application of this high-temperature polymorph as an electrolyte in SOFC requires temperatures above 730 °C. However, the doping allows -Bi2O3 stabilization to room temperature and opens the possibility for construction of SOFC that will operate at intermediate temperatures (ca. 350 °C) [2]. As it is found that some lanthanides are suitable dopants [3], the possibility to stabilize O2– ion conductors related to the -Bi2O3 polymorph in the Bi2O3–Tm2O3 system was investigated. Two starting mixtures with compositions (Bi1–xTmx )2O3 (x = 0.04 and 0.20) were homogenized in an agate mortar, heat treated at 750 °C for 3 h and then slowly furnace cooled. The samples were characterized by XRPD, DTA and SEI techniques. Based on XRPD, the single-phase tetragonal β-Bi2O3 was identified in the sample with x = 0.04. Its unit cell parameters, a = 7.742(2) and c = 5.650(2) Å, well-correspond to those of undoped β-Bi2O3 [4]. On the other hand, the cubic -Bi2O3 phase was obtained in the sample with x = 0.20. Its unit cell parameter was greater than the value reported for Tm-doped -Bi2O3 sample with x = 0.25 [3] (5.5033(9) vs. 5.478 Å). Both values are smaller than reported for undoped -Bi2O3 [4]. This means that the unit cell parameter of cubic -Bi2O3 decreases as Tm-content increases and it is in accordance with Tm3+ and Bi3+ ionic radii [5]. For the sample with x = 0.04, cyclic DTA curves showed one reversible β-Bi2O3 ↔ -Bi2O3 transition with corresponding temperatures: on heating, 660 °C, and, on cooling, 600 °C. Surprisingly, no phase transitions were observed in the sample with x = 0.20 which indicates that the obtained -Bi2O3 is stable within the whole investigated interval, i.e., from room temperature to 1000 °C. Electrochemical impedance of -Bi2O3 phase was measured in the following temperature range: 300 – 800 °C. At higher temperatures (600 – 800 °C) the conductivities are similar (0.11 – 0.32 S cm –1 ), but with lowering temperature they rapidly decrease, and amount, for example, 2.1·10–5 S cm–1 at 300 °C. As a consequence, two activation energies are found: 0.45(4) eV (600 – 800 °C), and 1.33(2) eV (300 – 600 °C). References: [1] P. Shuk, H.-D. Wiemhöfer, U. Guth, W. Göpel, M. Greenblatt, Solid State Ionics 89 (1996) 179 [2] E. D. Wachsman, K.T. Lee, Science 334 (2011) 935 [3] H. T. Cahen, T. G. M. Van Den Belt, J. H. W. De Wit, G. H. J. Broers, Solid State Ionics 1 (1980) 411 [4] H. A. Harwig, Z. anorg. allg. Chem. 444 (1978) 151 [5] R. D. Shannon, Acta Cryst. A 32 (1976) 751", publisher = "Univerzitet u Beogradu, Tehnološko-metalurški fakultet", journal = "8 th International Conference of the Chemical Societies of the South-East European Countries", title = "Tm(III)-doped d-Bi2O3 for solid - oxide fuel cells", pages = "188", url = "https://hdl.handle.net/21.15107/rcub_rimsi_2890" }
Dapčevć, A., Dejan, P., Rogan, J.,& Radojković, A.. (2013). Tm(III)-doped d-Bi2O3 for solid - oxide fuel cells. in 8 th International Conference of the Chemical Societies of the South-East European Countries Univerzitet u Beogradu, Tehnološko-metalurški fakultet., 188. https://hdl.handle.net/21.15107/rcub_rimsi_2890
Dapčevć A, Dejan P, Rogan J, Radojković A. Tm(III)-doped d-Bi2O3 for solid - oxide fuel cells. in 8 th International Conference of the Chemical Societies of the South-East European Countries. 2013;:188. https://hdl.handle.net/21.15107/rcub_rimsi_2890 .
Dapčevć, Aleksandra, Dejan, Poleti, Rogan, Jelena, Radojković, Aleksandar, "Tm(III)-doped d-Bi2O3 for solid - oxide fuel cells" in 8 th International Conference of the Chemical Societies of the South-East European Countries (2013):188, https://hdl.handle.net/21.15107/rcub_rimsi_2890 .