The compatibility of SrTi1−xCoxO3 perovskites (0 ≤ x ≤ 0.2) was evaluated for use as interconnect materials in solid oxide fuel cells (SOFCs). Although SrTi1−xCoxO3 perovskites have a single perovskite phase in the range of 0 ≤ x ≤ 0.2, it was observed for SrTi0.8Co0.2O3 that Co element agglomerated at the grain boundary during sintering. The dense SrTi0.8Co0.2O3 sample was destroyed and included Sr2TiO4 as a secondary phase after reducing treatment at 1000 °C. As a result of Co doping, the linear thermal expansion coefficient (TEC) increased remarkably with increasing Co content, but the TEC of SrTi0.9Co0.1O3 was comparable with those of SOFC cathodes and anodes. Co doping of SrTiO3 effectively increased electrical conductivity in air, whereas the conductivity of Co-doped SrTiO3 in a reducing atmosphere was much lower than that in air. This suggests that the Co ions3+/4+ in the perovskites were earlier reduced into Co2+ ions, compared to Ti4+ ions.

References

References
1.
Minh
,
N. Q.
, 1993, “
Ceramic Fuel Cells
,”
J. Am. Ceram. Soc.
,
76
(
3
), pp.
563
588
.
2.
Chan
,
N.-H.
,
Sharma
,
R. K.
, and
Smyth
,
D. M.
, 1981, “
Nonstoichiomery in SrTiO3
,”
J. Electrochem. Soc.
,
128
(
8
), pp.
1762
1769
.
3.
Tsukuda
,
H.
,
Okuma
,
S.
, and
Tomida
,
K.
, 2009, “
Influence of La Substitute on Sintering Behavior, Electronic Properties and Thermal Expansion of Sr11.5xLaxTiO3
,”
J. Jpn. Soc. Powder Metallurgy
,
56
(
2
), pp.
65
70
.
4.
Tomida
,
K.
,
Yamashita
,
A.
,
Tukuda
,
H.
,
Kabata
,
T.
,
Ikeda
,
K.
,
Hisatome
,
N.
, and
Yamazaki
,
Y.
, 2009, “
Optimization of Segmented-in-Series Tubular SOFCs With an (La, Sr)CoO3 System Cathode and the Generation Characteristics Under Pressurization
,”
Electrochemistry
,
77
(
12
), pp.
1018
1027
.
5.
Hui
,
S.
, and
Petric
,
A.
, 2002, “
Evaluation of Yttrium-Doped SrTiO3 as an Anode for Solid Oxide Fuel Cells
,”
J. Eur. Ceram. Soc.
,
22
, pp.
1673
1681
.
6.
Sun.
C.
, and
Stimming
,
U.
, 2007, “
Recent Anode Advances in Solid Oxide Fuel Cells
,”
J. Power Sources
,
171
, pp.
247
260
.
7.
Kurokawa
,
H.
,
Yang
,
L.
,
Jacobson
,
C. P.
,
De Jonghe
,
L. C.
, and
Visco.
,
S. J.
, 2007, “
Y-Doped SrTiO3 Based Sulfur Tolerant Anode for Solid Oxide Fuel Cells
,”
J. Power Sources
,
164
, pp.
510
518
.
8.
Fu
,
Q.
,
Tietz
,
F.
,
Sebold
,
D.
,
Tao
,
S.
, and
Irvine
,
J. T. S.
, 2007, “
An Efficient Ceramic-Based Anode for Solid Oxide Fuel Cells
,”
J. Power Sources
,
171
, pp.
663
669
.
9.
Gong
,
M.
,
Liu
,
X.
,
Trembly
,
J.
, and
Johnson
,
C.
, 2007, “
Sulfur-Tolerant Anode Materials for Solid Oxide Fuel Cell Application
,”
J. Power Sources
,
168
, pp.
289
298
.
10.
Gao
,
F.
,
Zhao
,
H.
,
Li
,
X.
,
Cheng
,
Y.
,
Zhou
,
X.
, and
Cui
,
F.
, 2008, “
Preparation and Electrical Properties of Yttrium-Doped Strontium Titanate With B-site Deficiency
,”
J. Power Sources
,
185
, pp.
26
31
.
11.
Sun
,
X.
,
Wang
,
S.
,
Wang
,
Z.
,
Ye
,
X.
,
Wen
,
T.
, and
Huang
,
F.
, 2008, “
Anode Performance of LST-xCeO2 for Solid Oxide Fuel Cells
,”
J. Power Soruces
,
183
, pp.
114
117
.
12.
Fu
,
Q. X.
,
Mi
,
S. B.
,
Wessel
,
E.
, and
Tietz
,
F.
, 2008, “
Influence of Sintering Conditions on Microstructure and Electrical Conductivity Yttrium-Substituted SrTiO3
,”
J. Eur. Ceram. Soc.
,
28
, pp.
881
820
.
13.
Sun
,
X.
,
Wang
,
S.
,
Wang
,
Z.
,
Qian
,
J. X.
,
Wen
,
T.
, and
Huang
,
F.
, 2009, “
Evaluation of Sr0.88Y0.08TiO3-CeO2 as Composite Anode for Solid Oxide Fuel Cells Running on CH4 Fuel
”,
J. Power Sources
,
187
, pp.
85
89
.
14.
Escudero
,
M. J.
,
Irvine
,
J. T. S.
, and
Daza
,
L.
, 2009, “
Development of Anode Material Based on La-Substitute SrTiO3 Perovskites Doped With Manganese and/or Gallium for SOFC
,”
J. Power Sources
,
192
, pp.
43
50
.
15.
Ma
,
Q.
,
Rietz
,
F.
,
Sebold
,
D.
, and
Stöver
,
D.
, 2010, “
Y-Substituted SrTiO3-YSZ Composites as Anode Materials for Solid Oxide Fuel Cells: Interaction Between SYT and YSZ
,”
J. Power Sources
,
195
, pp.
1920
1925
.
16.
Yoo
,
K. B.
, and
Choi
,
G. M.
, 2009, “
Co-Doped La0.2Sr0.8TiO3 as a Possible Anode for the LaGaO3-based Solid Oxide Fuel Cell
,”
ECS Trans.
,
25
(
2
), pp.
2259
2266
.
17.
Li
,
X.
,
Zhao
,
H.
,
Gao
,
F.
,
Zhu
,
Z.
,
Chen
,
N.
, and
Shen
,
W.
, 2008, “
Synthesis and Electrical Properties of Co-Doped Y0.08Sr0.92TiO3δ as a Potential SOFC Anode
,”
J. Power Sources
,
179
, pp.
1588
1592
.
18.
Zhao
,
H.
,
Gao
,
F.
,
Li
,
X.
,
Zhang
,
C.
, and
Zhao
,
Y.
, 2009, “
Electrical Properties of Yttrium Doped Strontium Titanate With A-site Deficiency as Potential Anode Materials for Solid Oxide Fuel Cells
,”
J. Power Sources
,
180
, pp.
193
197
.
19.
Kharton
,
V. V.
,
Shuangbao
,
L.
,
Kovalensky
,
A. V.
, and
Naumovich
,
E. N.
, 1997, “
Oxygen Permeability of Perovskites in the System SrCoO3δ-SrTiO3
”,
Solid State Ionics
,
96
, pp.
141
151
.
20.
Anderson
,
H. U.
, 1992, “
Review of p-Type Doped Perovskite Materials for SOFC and Other Application
,”
Solid State Ionics
,
52
, pp.
33
41
.
21.
Koc
,
R.
, and
Anderson
,
H. U.
, 1992, “
Liquid Phase Sintering of LaCrO3
,”
J. Eur. Ceram. Soc.
,
9
, pp.
285
292
.
22.
Kleinlogel
,
C.
, and
Gauckler
,
L. J.
, 2000, “
Sintering and Properties of Nanosized Ceria Solid Solution
,”
Solid State Ionics
,
135
, pp.
567
573
.
23.
Navas
,
C.
, and
Loye
,
H.-C.
, 1997, “
Conductivity Studies on Oxygen-Deficient Ruddlesden-Popper Phase
,”
Solid State Ionics
,
93
, pp.
171
176
.
24.
Takeuchi
,
T.
,
Tani
,
T.
, and
Satoh
,
T.
, 1998, “
Microcomposite Particles Sr3Ti2O7-SrTiO3 With an Epitaxial Core-Shell Structure
,”
Solid State Ionics
,
108
, pp.
67
71
.
25.
Sugimoto
,
W.
,
Shirata
,
M.
,
Takemoto
,
M.
,
Hayami
,
S.
,
Sugahara
,
Y.
, and
Kuroda
,
K.
, “
Synthesis and Structures of Carrier Doped Titanates With the Ruddlesden-Popper Structure (Sr0.95La0.05)n+1TinO3n+1(n = 1,2)
,”
Solid State Ionics
,
108
, pp.
315
319
.
26.
Roth
,
R. S.
, 1957,
“Classification of Perovskite and Other ABO3-Type Compounds,” J. Res. NBS
,
RP2736
,
58
(
2
), pp.
75
88
.
27.
Takeda
,
Y.
,
Kanno
,
R.
,
Takada
,
T.
,
Yamamoto
,
O.
,
Takano
,
M.
, and
Bando
,
Y.
, 1986, “
Phase Relation and Oxygen-Non-Stoichiometry of Perovskite-Like Compound SrCoOx(2.29 < x < 2.80)
,
Anorg. Allg. Chem.
,
540/541
, pp.
259
270
.
28.
Vashook
,
V. V.
,
Zinkevich
,
M. V.
, and
Zonov
,
Y. G.
, 1999, “
Phase Relations in Oxygen-Deficient SrCoO2.5δ
,”
Solid State Ionics
,
116
, pp.
129
138
.
29.
Shannon
,
R. D.
, and
Previtt
,
C. T.
, 1969, “
Effective Ionic Radii in Oxides and Flourides
,”
Acta Cryst.
,
B25
, pp.
925
946
.
30.
Yasuda
,
I.
, and
Hishinuma
,
M.
, 2000, “
Lattice Expansion of Acceptor-Doped Lathanum Chromites Under High-Temperature Reducing Atmospheres
,”
Electrochemistry
,
68
(
6
), pp.
526
530
.
31.
Hayashi
,
H.
,
Saitou
,
T.
,
Maruyama
,
N.
,
Inaba
,
H.
,
Kawamura
,
K.
, and
Mori
,
M.
, 2005, “
Thermal Expansion Coefficient of Yttria Stabilized Zirconia for Various Yttria Content
,”
Solid State Ionics
,
176
, pp.
613
619
.
32.
Wang
,
Z.
,
Hashimoto
,
S.
, and
Mori
,
M.
, 2009, “
Investigation and Optimization of Interface Reactivity Between Ce0.9Gd0.1O1.95 and Zr0.89Sc0.1Ce0.01O2δ for High Performance Intermediate Temperature-Solid Oxide Fuel Cells
,”
J. Power Sources
,
193
, pp.
49
54
.
33.
Suda
,
E.
,
Pacaud
,
B.
,
Montardi
,
Y.
,
Mori
,
M.
, and
Takeda
,
Y.
, 2004, “
Electrical and Thermal Properties of Dense CE1−xRExO2−δ Electrolyte Using Low-Temperature Sinterable Powder (0 ≤ x ≤ 0.2, RE = Y, Sm, Gd)
,”
Trans. Mater. Res. Soc. Jpn.
,
29
(
5
), pp.
2317
2320
.
34.
Mori
,
M.
,
Hiei
,
Y.
,
Sammes
,
N. M.
, and
Tompsett
,
G. A.
, 2000, “
Thermal-Expansion Behaviors and Mechanisms for Ca- or Sr-Doped Lanthanum Manganite Perovskites Under Oxidizing Atmosphere
,”
J. Electrochem. Soc.
,
147
(
4
), pp.
1295
1302
.
35.
Tai
,
L.-W.
,
Nasrallah
,
M. M.
,
Anderson
,
H. U.
,
Sparlin
,
D. M.
, and
Sehlin
,
S. R.
, 1995, “
Structure and Electrical Properties of La1−xSrxCo1−yFeyO3. Part 1. The System La0.8Sr0.2Co1−yFeyO3
,”
Solid State Ionics
,
76
, pp.
259
271
.
36.
Tai
,
L.-W.
,
Nasrallah
,
M. M.
,
Anderson
,
H. U.
,
Sparlin
,
D. M.
, and
Sehlin
,
S. R.
, 1995, “
Structure and Electrical Properties of La1−xSrxCo1−yFeyO3. Part 2. The System La1−xSrxCo0.2Fe0.8O3
,”
Solid State Ionics
,
76
, pp.
273
283
.
37.
Mori
,
M.
,
Yamamoto
,
T.
,
Itoh
,
H.
,
Inaba
,
H.
, and
Tagawa
,
H.
, 1998, “
Thermal Expansion of Nickel-Zirconia Anodes in Solid Oxide Fuel Cells During Fabrication and Operation
,”
J. Electrochem. Soc.
,
145
(
4
), pp.
1374
1381
.
38.
Mori
,
M.
,
Yamamoto
,
T.
,
Itoh
,
H.
, and
Watanabe
T.
, 1997, “
Compatibility of Alkaline Earth Metal (Mg, Ca, Sr)-Doped Lanthanum Chromites as Separators in Planar-Type High-Temperature Solid Oxide Fuel Cells
,”
J. Mater. Sci.
,
32
, pp.
2423
2431
.
39.
Yasuda
,
I.
, and
Hishinuma
,
M.
, 1995, “
Electrical Conductivity and Chemical Diffusion Coefficient of Sr-Doped Lanthanum Chromites
,”
Solid State Ionics
,
80
, pp.
141
150
.
40.
Yasuda
,
I.
, and
Hishinuma
,
M.
, 1995, “
Electrochemical Properties of Doped Lanthanum Chromites as Interconnectors for Solid Oxide Fuel Cells
,”
J. Electrochem. Soc.
,
143
, pp.
1583
1590
.
You do not currently have access to this content.