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Novel BaBi0.05Co0.8Ta0.15O3−δ cathode material for intermediate temperature solid oxide fuel cells
Accepted Manuscript Novel BaBi0.05Co0.8Ta0.15O3− δ cathode material for intermediate temperature solid oxide fuel cells Ye Cheng, Qingjun Zhou, Libing Chen, Yantao Xie PII: DOI: Reference:
S0167-577X(17)30073-3 http://dx.doi.org/10.1016/j.matlet.2017.01.066 MLBLUE 22019
To appear in:
Materials Letters
Received Date: Revised Date: Accepted Date:
16 August 2016 30 December 2016 15 January 2017
Please cite this article as: Y. Cheng, Q. Zhou, L. Chen, Y. Xie, Novel BaBi0.05Co0.8Ta0.15O3− δ cathode material for intermediate temperature solid oxide fuel cells, Materials Letters (2017), doi: http://dx.doi.org/10.1016/j.matlet. 2017.01.066
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Novel BaBi0.05Co0.8Ta 0.15O3−δ cathode material for intermediate temperature solid oxide fuel cells Ye Cheng, Qingjun Zhou*, Libing Chen, Yantao Xie College of science, Civil Aviation University of China, Tianjin 300300, PR China *Corresponding author College of science, Civil Aviation University of China, Tianjin 300300, PR China E-mail address: [email protected] (Q. Zhou), [email protected] (Q. Zhou) Abstract Cathode material BaBi0.05Co0.8Ta0.15O3−δ (BBCT) was synthesized by a solid-state reaction for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The X-ray techniques had been used for structural characterizations. BBCT forms a pure cubic perovskite structure and exhibits chemical compatibility with the La0.9Sr0.1Ga0.8Mg0.2O3−δ (LSGM) electrolyte. The thermal expansion coefficient (TEC) of the BBCT is 20×10−6 K−1. The electrical conductivity are 7.4−10.7 S cm−1 in the temperature range of 600−800 °C in ambient air . The polarization resistance (RP) of BBCT cathode on LSGM electrolyte is 0.023, 0.036, 0.065 Ω cm2 at 800, 750, 700 °C, respectively. Maximum power density is 664 mW cm−2 at 800 °C. The encouraging results promise BBCT as an alternative cathode material for IT-SOFCs. Key words: BaBi0.05Co0.8Ta0.15O3−δ, X-ray techniques, structural, sintering 1. Introduction Solid oxide fuel cell(SOFC) has attracted much attention due to the advantages of
1
high efficiency, low pollutant emission, fuel flexibility, secure and environmental friendly [1,2]. To date, lowering of the operation temperatures has been a trend for decreasing the fabrication cost, while which will lead to the decrease in the performance of the fuel cells[3]. It is urgent to exploit the cathode materials with highly catalytic activity in intermediate-temperature range . Some mixed ionic and electronic conductors(MIECs), such as SrCoO3−δ based perovskite oxides, are considered as the promising cathode materials. The SrCoO3−δ oxides exist several phase structures at different temperature and only the cubic phase in the high temperature shows the highest conductivity and oxygen permeation property[4,5]. One strategy to stabilize the high temperature cubic phase of SrCoO3−δ at low temperatures is partial substitution in their A-site or B-site cations and the oxides with fully occupied A-site by barium show attractive permeation properties[6]. Recently, Liao et al reported that BaBi0.05Co0.8Ta0.15O3−δ (BBCT) perovskite oxide was a high performance oxygen-permeable membrane material. The Ta-doping on the B-site has improved the structure stability and the Bi-doping has enhanced the phase stability further and the oxygen permeability [7,8]. However, the performance of BBCT as cathode material for SOFC has not been explored. Therefore, the investigation on the behaviors of BBCT cathode may be of importance. In this work, the perovskite oxide BBCT was synthesized and electrochemical properties had also been studied in depth. 2. Experimental details BaBi0.05Co 0.8Ta0.15O3−δ (BBCT) oxide was synthesized by the solid state reaction.
2
The raw materials BaCO3 (99.95%), Bi2O3 (99.999%), Co3O4 (99.9%) and Ta2O5 (99.99%) were weighed accurately in accordance with the stoichiometric ratio and mixed inside a planetary mill using ethanol as media. After ball milling and drying, the powders were pressed into disks and calcined. The processes including grinding, drying, pressing, sintering were repeated and the calcination conditions were 800,1000 and 1100 °C for 10 h, respectively. For measurement purposes, LSGM, Ce0.8Sm0.2O1.9 (SDC) and NiO powders were synthesized by the glycine-nitrate process according to Refs [9]. The crystal structure of BBCT and chemical compatibility between cathode BBCT and LSGM electrolyte were identified by powder X-ray diffraction (Rigaku-D/Max Ra system). The mixed powders of BBCT and LSGM (50:50 by weight) were calcined at 1000 °C for 5 h. Electrical conductivity was measured by the standard dc four-terminal method in the temperature range of 300−850 °C. The measurements of TECs curves were from 30 °C to 1000 °C with a Netzsch DIL 402C dilatometer and the air-purge flow rate was 60 ml min−1. The electrochemical impedance spectroscopy (EIS) of the symmetrical cell was measured by Zaher Im6ex frequency electrochemical workstation within the temperature range of 600−800 °C at intervals of 50 °C. The frequency range was from 100 KHz to 0.1 Hz with the signal amplitude of 10 mV under open circuit. Electrolyte supported single cell of BBCT/LSGM/SDC/Ni-SDC was fabricated with 0.3 mm thick LSGM electrolyte discs. To prevent the reaction of LSGM and anode, a layer of SDC was screen-painted onto the LSGM electrolyte and sintered at 1300 °C for 1 h in air. After that, the NiO−SDC (65:35 by weight) anode was screen-painted on
3
the SDC layer and sintered at 1250 °C for 4 h. The BBCT cathode was screen-painted on the opposite side of the LSGM disc, following by sintering at 1000 °C for 2 h. 3.
Results and discussion
Fig. 1. XRD patterns of the samples: (a) BBCT, (b) BBCT−LSGM mixture sintered at 1000 °C for 5 h and (c) LSGM.
Fig. 1(a) shows the XRD pattern of the BBCT sample calcined at 1100 °C for 10 h. It can be seen that BBCT forms a pure cubic perovskite structure without any impurities observed. As shown in Fig.1(b), no additional diffraction peaks and peak shifts are identified within the limits of the XRD measurement, which indicates that BBCT cathode and LSGM electrolyte are chemically compatible at 1000 °C for 5 h. While the long-term stability of BBCT and LSGM composites needs to be further investigated.
Fig. 2. The thermal expansion curve for BBCT sample.
The TEC curve of BBCT sample is depicted in Fig.2. It is obvious that the thermal expansion curve is not totally linear in all the temperature range. The transition of the thermal expansion curve at around 170 °C was observed and the gradient of the curves
4
of ∆L/L related to the temperature become larger. It can be attributable to the loss of lattice oxygen and the formation of oxygen vacancies with the increasing temperature. In order to maintain the charge neutrality, a reduction of Co4+ to Co3+ would occur, the element of lower valence state with bigger ionic radii caused the lattice expansion. The average TEC of the BBCT sample is 20×10−6 K−1, which is higher than that of LSGM (11.3 ×10−6 K−1) but in the range of those presented materials such as 19.1×10−6 K−1 for SmBaCo 2O5+δ [10] and 24.3×10 −6 K−1 for LaBaCo 2O5+δ [11].
Fig. 3. (a) Electrical conductivity of BBCT measured in 300–850 °C and (b) Arrhenius plots of the electrical conductivity.
The temperature dependence of the electrical conductivity and the corresponding Arrhenius plots are presented in Fig.3. The conductivity becomes larger with the increase of temperature, exhibiting a semiconductor-like behavior. It can be described well by a small polar hopping mechanism, following by the formula: σ=(A/T) exp (−Ea/(kT)), where σ is the electrical conductivity, A is a material constant, T is the absolute temperature and k is the Boltzmann constant. The conductivity values of the BBCT sample are 7.4−10.7 S cm −1 in the temperature range of 600−800 °C, which is similar to that of BaBi0.05Co0.8Nb0.15O3−δ [11]. The donor doping of tantalum at the B site may decrease the concentration of the electron holes as charge compensation and then
5
result in the low electrical conductivities. The activation energy is 22.6 kJ mol−1 calculated from the slope of the Arrhenius plots.
Fig. 4. (a) Temperature dependence of RP for BBCT and (b) cell voltage and power density for single cells with BBCT cathode.
Fig.4(a) shows the impedance spectra of BBCT cathode on LSGM electrolyte measured in the temperature range of 600−800 °C in air. It can be found that the EIS of BBCT contains two separable depressed arcs, indicating that there are at least two electrically capacitive processes. The high-frequency arc is likely related to the charge transfer process at the electrode/electrolyte interface. The low-frequency arc can be attributed to the oxygen adsorption and desorption on the electrode surface and the oxygen ions diffusion [12−14]. The charge transport, gas migration and the electrochemical reactions will all be enhanced with the increasing temperature and then result in the decrease of RP at elevated temperatures. The RP values of BBCT cathode on LSGM electrolyte are 0.023, 0.036, 0.065 Ω cm2 at 800, 750, 700 °C, respectively. These values over 700 °C are much lower than that expected for the RP of the cathode (0.15 Ω cm2 at the operating temperature) [15]. It indicated that BBCT exhibited high catalytic activity for the oxygen reduction reaction (ORR). Fig.4 (b) shows the typical I-V and I-P curves of electrolyte-supported single cell,
6
consisting of NiO−SDC anode, LSGM electrolyte, BBCT cathode and SDC protection layer, tested at 600−800 °C using humidified hydrogen (~3% H2O) as the fuel and ambient air as the oxidant. The maximum power densities are about 664, 475and 319 mW cm−2 at 800, 750, and 700 °C, respectively. They are closed to the cells of NiO–SDC/SDC/LSGM/BBCN [11] with the maximum power densities are 610, 478 and 334 mW cm−2 at 800, 750 and 700 °C, respectively. 4.
Conclusions In summary, the cubic perovskite oxide BBCT is synthesized and estimated as
cathode material for IT-SOFCs. The XRD results reveal that the chemical compatibility between the BBCT cathode and the LSGM electrolyte is quite well. The electrical conductivity becomes larger with the increasing temperature . The RP of BBCT cathode on LSGM electrolyte is 0.023 Ω cm2 at 800 °C. The maximum power densities are about 664, 475and 319 mW cm−2 at 800, 750, and 700 °C, respectively. The encouraging results indicate that BBCT could be a highly promising oxygen reduction electrode candidate for practical applications of IT-SOFCs. Acknowledgements The research was financially supported by the Tianjin Research Program of Application Foundation and Advanced Technology (15JCYBJC48700) and Fundamental Research Funds for the Central Universities (Y16−24). References [1] A.J. Jacobson, Chem. Mater. 22 (2010) 660−674.
7
[2] C.S. Song, Catal. Today. 77 (2002) 17−49. [3] C.R. Xia, W. Rauch, F.L. Chen, M.L. Liu, Solid. State. Ion.149(2002)11-19. [4]C. de. la. Calle, A. Aguadero, J.A. Alonso, M. T. Fernández-Díaz. Solid. State. Ion.10 (2008) 1924-1935. [5] Z.Q. Deng, W.S. Yang, W Liu, C.S.Chen, J. Solid. State. Chem. 179 (2006) 362-369. [6]T. Ishihara, S. Fukui, H. Nishigushi, Y. Takita, Solid. State. Ion.152–153 (2002) 609– 613. [7] Q. Liao, Y.J. Wang, Y. Chen, Y.Y Wei, H.H Wang, J. Membrane. Sci. 468 (2014) 184−191. [8] H.W. Cheng, W.L. Yao, X.G. Lu, Z.F. Zhou, C.H. Li, J.Z. Liu, Fuel. Process. Technol. 131 (2015) 36–44. [9] Y. Cheng, Q.J. Zhou, W.D. Li, T. Wei, Z.P. Li, D.M An, X.Q. Tong, Z.H. Ji, X. Han, J. Alloy. Compd. 641 (2015) 234–237. [10] Q. Zhou, F. Wang, Y. Shen, T. He, J. Power. Sources. 195 (2010) 2174−2181 [11] Q.J. Zhou, T. Wei, Z.P. Li, D.M An, X.Q. Tong, Z.H. Ji, W.B Wang, H. Lu, L.Y. Sun, Z.Y Zhang, K. Xu, J. Alloy. Compd. 627 (2015) 320−323. [12] S. B. Adler, Solid. State. Ion. 135 (2000) 603−612. [13] M.J. Jørgensen, M. Mogensen, J. Electrochem. Soc. 148 (2001) A433−A442. [14] C.J. Fu, K.N. Sun, N.Q. Zhang, X.B. Chen, D.R. Zhou, Electrochim. Acta. 52 (2007) 4589−4594. [15] B. C. H. Steele, Solid. State. Ion. 86–88 (1996) 1223−1234.
8
Highlights • BaBi0.05Co0.8Ta0.15O3−δ oxides are developed as cathode materials for IT-SOFCs. • BaBi0.05Co0.8Ta0.15O3−δ cathode shows the high ORR activity between 600 and 800 °C. • Power density of the cell with BaBi0.05Co 0.8Ta0.15O3−δ achieves 664 mW cm−2 at 800 °C.
9
S0167-577X(17)30073-3 http://dx.doi.org/10.1016/j.matlet.2017.01.066 MLBLUE 22019
To appear in:
Materials Letters
Received Date: Revised Date: Accepted Date:
16 August 2016 30 December 2016 15 January 2017
Please cite this article as: Y. Cheng, Q. Zhou, L. Chen, Y. Xie, Novel BaBi0.05Co0.8Ta0.15O3− δ cathode material for intermediate temperature solid oxide fuel cells, Materials Letters (2017), doi: http://dx.doi.org/10.1016/j.matlet. 2017.01.066
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Novel BaBi0.05Co0.8Ta 0.15O3−δ cathode material for intermediate temperature solid oxide fuel cells Ye Cheng, Qingjun Zhou*, Libing Chen, Yantao Xie College of science, Civil Aviation University of China, Tianjin 300300, PR China *Corresponding author College of science, Civil Aviation University of China, Tianjin 300300, PR China E-mail address: [email protected] (Q. Zhou), [email protected] (Q. Zhou) Abstract Cathode material BaBi0.05Co0.8Ta0.15O3−δ (BBCT) was synthesized by a solid-state reaction for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The X-ray techniques had been used for structural characterizations. BBCT forms a pure cubic perovskite structure and exhibits chemical compatibility with the La0.9Sr0.1Ga0.8Mg0.2O3−δ (LSGM) electrolyte. The thermal expansion coefficient (TEC) of the BBCT is 20×10−6 K−1. The electrical conductivity are 7.4−10.7 S cm−1 in the temperature range of 600−800 °C in ambient air . The polarization resistance (RP) of BBCT cathode on LSGM electrolyte is 0.023, 0.036, 0.065 Ω cm2 at 800, 750, 700 °C, respectively. Maximum power density is 664 mW cm−2 at 800 °C. The encouraging results promise BBCT as an alternative cathode material for IT-SOFCs. Key words: BaBi0.05Co0.8Ta0.15O3−δ, X-ray techniques, structural, sintering 1. Introduction Solid oxide fuel cell(SOFC) has attracted much attention due to the advantages of
1
high efficiency, low pollutant emission, fuel flexibility, secure and environmental friendly [1,2]. To date, lowering of the operation temperatures has been a trend for decreasing the fabrication cost, while which will lead to the decrease in the performance of the fuel cells[3]. It is urgent to exploit the cathode materials with highly catalytic activity in intermediate-temperature range . Some mixed ionic and electronic conductors(MIECs), such as SrCoO3−δ based perovskite oxides, are considered as the promising cathode materials. The SrCoO3−δ oxides exist several phase structures at different temperature and only the cubic phase in the high temperature shows the highest conductivity and oxygen permeation property[4,5]. One strategy to stabilize the high temperature cubic phase of SrCoO3−δ at low temperatures is partial substitution in their A-site or B-site cations and the oxides with fully occupied A-site by barium show attractive permeation properties[6]. Recently, Liao et al reported that BaBi0.05Co0.8Ta0.15O3−δ (BBCT) perovskite oxide was a high performance oxygen-permeable membrane material. The Ta-doping on the B-site has improved the structure stability and the Bi-doping has enhanced the phase stability further and the oxygen permeability [7,8]. However, the performance of BBCT as cathode material for SOFC has not been explored. Therefore, the investigation on the behaviors of BBCT cathode may be of importance. In this work, the perovskite oxide BBCT was synthesized and electrochemical properties had also been studied in depth. 2. Experimental details BaBi0.05Co 0.8Ta0.15O3−δ (BBCT) oxide was synthesized by the solid state reaction.
2
The raw materials BaCO3 (99.95%), Bi2O3 (99.999%), Co3O4 (99.9%) and Ta2O5 (99.99%) were weighed accurately in accordance with the stoichiometric ratio and mixed inside a planetary mill using ethanol as media. After ball milling and drying, the powders were pressed into disks and calcined. The processes including grinding, drying, pressing, sintering were repeated and the calcination conditions were 800,1000 and 1100 °C for 10 h, respectively. For measurement purposes, LSGM, Ce0.8Sm0.2O1.9 (SDC) and NiO powders were synthesized by the glycine-nitrate process according to Refs [9]. The crystal structure of BBCT and chemical compatibility between cathode BBCT and LSGM electrolyte were identified by powder X-ray diffraction (Rigaku-D/Max Ra system). The mixed powders of BBCT and LSGM (50:50 by weight) were calcined at 1000 °C for 5 h. Electrical conductivity was measured by the standard dc four-terminal method in the temperature range of 300−850 °C. The measurements of TECs curves were from 30 °C to 1000 °C with a Netzsch DIL 402C dilatometer and the air-purge flow rate was 60 ml min−1. The electrochemical impedance spectroscopy (EIS) of the symmetrical cell was measured by Zaher Im6ex frequency electrochemical workstation within the temperature range of 600−800 °C at intervals of 50 °C. The frequency range was from 100 KHz to 0.1 Hz with the signal amplitude of 10 mV under open circuit. Electrolyte supported single cell of BBCT/LSGM/SDC/Ni-SDC was fabricated with 0.3 mm thick LSGM electrolyte discs. To prevent the reaction of LSGM and anode, a layer of SDC was screen-painted onto the LSGM electrolyte and sintered at 1300 °C for 1 h in air. After that, the NiO−SDC (65:35 by weight) anode was screen-painted on
3
the SDC layer and sintered at 1250 °C for 4 h. The BBCT cathode was screen-painted on the opposite side of the LSGM disc, following by sintering at 1000 °C for 2 h. 3.
Results and discussion
Fig. 1. XRD patterns of the samples: (a) BBCT, (b) BBCT−LSGM mixture sintered at 1000 °C for 5 h and (c) LSGM.
Fig. 1(a) shows the XRD pattern of the BBCT sample calcined at 1100 °C for 10 h. It can be seen that BBCT forms a pure cubic perovskite structure without any impurities observed. As shown in Fig.1(b), no additional diffraction peaks and peak shifts are identified within the limits of the XRD measurement, which indicates that BBCT cathode and LSGM electrolyte are chemically compatible at 1000 °C for 5 h. While the long-term stability of BBCT and LSGM composites needs to be further investigated.
Fig. 2. The thermal expansion curve for BBCT sample.
The TEC curve of BBCT sample is depicted in Fig.2. It is obvious that the thermal expansion curve is not totally linear in all the temperature range. The transition of the thermal expansion curve at around 170 °C was observed and the gradient of the curves
4
of ∆L/L related to the temperature become larger. It can be attributable to the loss of lattice oxygen and the formation of oxygen vacancies with the increasing temperature. In order to maintain the charge neutrality, a reduction of Co4+ to Co3+ would occur, the element of lower valence state with bigger ionic radii caused the lattice expansion. The average TEC of the BBCT sample is 20×10−6 K−1, which is higher than that of LSGM (11.3 ×10−6 K−1) but in the range of those presented materials such as 19.1×10−6 K−1 for SmBaCo 2O5+δ [10] and 24.3×10 −6 K−1 for LaBaCo 2O5+δ [11].
Fig. 3. (a) Electrical conductivity of BBCT measured in 300–850 °C and (b) Arrhenius plots of the electrical conductivity.
The temperature dependence of the electrical conductivity and the corresponding Arrhenius plots are presented in Fig.3. The conductivity becomes larger with the increase of temperature, exhibiting a semiconductor-like behavior. It can be described well by a small polar hopping mechanism, following by the formula: σ=(A/T) exp (−Ea/(kT)), where σ is the electrical conductivity, A is a material constant, T is the absolute temperature and k is the Boltzmann constant. The conductivity values of the BBCT sample are 7.4−10.7 S cm −1 in the temperature range of 600−800 °C, which is similar to that of BaBi0.05Co0.8Nb0.15O3−δ [11]. The donor doping of tantalum at the B site may decrease the concentration of the electron holes as charge compensation and then
5
result in the low electrical conductivities. The activation energy is 22.6 kJ mol−1 calculated from the slope of the Arrhenius plots.
Fig. 4. (a) Temperature dependence of RP for BBCT and (b) cell voltage and power density for single cells with BBCT cathode.
Fig.4(a) shows the impedance spectra of BBCT cathode on LSGM electrolyte measured in the temperature range of 600−800 °C in air. It can be found that the EIS of BBCT contains two separable depressed arcs, indicating that there are at least two electrically capacitive processes. The high-frequency arc is likely related to the charge transfer process at the electrode/electrolyte interface. The low-frequency arc can be attributed to the oxygen adsorption and desorption on the electrode surface and the oxygen ions diffusion [12−14]. The charge transport, gas migration and the electrochemical reactions will all be enhanced with the increasing temperature and then result in the decrease of RP at elevated temperatures. The RP values of BBCT cathode on LSGM electrolyte are 0.023, 0.036, 0.065 Ω cm2 at 800, 750, 700 °C, respectively. These values over 700 °C are much lower than that expected for the RP of the cathode (0.15 Ω cm2 at the operating temperature) [15]. It indicated that BBCT exhibited high catalytic activity for the oxygen reduction reaction (ORR). Fig.4 (b) shows the typical I-V and I-P curves of electrolyte-supported single cell,
6
consisting of NiO−SDC anode, LSGM electrolyte, BBCT cathode and SDC protection layer, tested at 600−800 °C using humidified hydrogen (~3% H2O) as the fuel and ambient air as the oxidant. The maximum power densities are about 664, 475and 319 mW cm−2 at 800, 750, and 700 °C, respectively. They are closed to the cells of NiO–SDC/SDC/LSGM/BBCN [11] with the maximum power densities are 610, 478 and 334 mW cm−2 at 800, 750 and 700 °C, respectively. 4.
Conclusions In summary, the cubic perovskite oxide BBCT is synthesized and estimated as
cathode material for IT-SOFCs. The XRD results reveal that the chemical compatibility between the BBCT cathode and the LSGM electrolyte is quite well. The electrical conductivity becomes larger with the increasing temperature . The RP of BBCT cathode on LSGM electrolyte is 0.023 Ω cm2 at 800 °C. The maximum power densities are about 664, 475and 319 mW cm−2 at 800, 750, and 700 °C, respectively. The encouraging results indicate that BBCT could be a highly promising oxygen reduction electrode candidate for practical applications of IT-SOFCs. Acknowledgements The research was financially supported by the Tianjin Research Program of Application Foundation and Advanced Technology (15JCYBJC48700) and Fundamental Research Funds for the Central Universities (Y16−24). References [1] A.J. Jacobson, Chem. Mater. 22 (2010) 660−674.
7
[2] C.S. Song, Catal. Today. 77 (2002) 17−49. [3] C.R. Xia, W. Rauch, F.L. Chen, M.L. Liu, Solid. State. Ion.149(2002)11-19. [4]C. de. la. Calle, A. Aguadero, J.A. Alonso, M. T. Fernández-Díaz. Solid. State. Ion.10 (2008) 1924-1935. [5] Z.Q. Deng, W.S. Yang, W Liu, C.S.Chen, J. Solid. State. Chem. 179 (2006) 362-369. [6]T. Ishihara, S. Fukui, H. Nishigushi, Y. Takita, Solid. State. Ion.152–153 (2002) 609– 613. [7] Q. Liao, Y.J. Wang, Y. Chen, Y.Y Wei, H.H Wang, J. Membrane. Sci. 468 (2014) 184−191. [8] H.W. Cheng, W.L. Yao, X.G. Lu, Z.F. Zhou, C.H. Li, J.Z. Liu, Fuel. Process. Technol. 131 (2015) 36–44. [9] Y. Cheng, Q.J. Zhou, W.D. Li, T. Wei, Z.P. Li, D.M An, X.Q. Tong, Z.H. Ji, X. Han, J. Alloy. Compd. 641 (2015) 234–237. [10] Q. Zhou, F. Wang, Y. Shen, T. He, J. Power. Sources. 195 (2010) 2174−2181 [11] Q.J. Zhou, T. Wei, Z.P. Li, D.M An, X.Q. Tong, Z.H. Ji, W.B Wang, H. Lu, L.Y. Sun, Z.Y Zhang, K. Xu, J. Alloy. Compd. 627 (2015) 320−323. [12] S. B. Adler, Solid. State. Ion. 135 (2000) 603−612. [13] M.J. Jørgensen, M. Mogensen, J. Electrochem. Soc. 148 (2001) A433−A442. [14] C.J. Fu, K.N. Sun, N.Q. Zhang, X.B. Chen, D.R. Zhou, Electrochim. Acta. 52 (2007) 4589−4594. [15] B. C. H. Steele, Solid. State. Ion. 86–88 (1996) 1223−1234.
8
Highlights • BaBi0.05Co0.8Ta0.15O3−δ oxides are developed as cathode materials for IT-SOFCs. • BaBi0.05Co0.8Ta0.15O3−δ cathode shows the high ORR activity between 600 and 800 °C. • Power density of the cell with BaBi0.05Co 0.8Ta0.15O3−δ achieves 664 mW cm−2 at 800 °C.
9