Decomposition pathway of cubic Ba0.5Sr0.5Co0.8Fe0.2O3−δ between 700°C and 1000°C analyzed by electron microscopic techniques

Müller, Philipp; Störmer, Heike; Dieterle, Levin; Niedrig, Christian; Ivers-Tiffée, Ellen; Gerthsen, D.

doi:10.1016/j.ssi.2011.10.013

Cited by 58 publications

(72 citation statements)

References 36 publications

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“…Recently, Poetzsch et al have reported significant proton conductivity in mixed conducting Ba 0.5 Sr 0.5 Fe 0.8 Zn 0.2 O 3−δ (BSFZ) [22], which exhibits a total electrical conductivity of 9.4 Scm −1 at 590°C [23]. BSCF, which is one of the highest performing SOFC cathode candidate materials, suffers from poor chemical stability under preparation and operating conditions [24].…”

Section: Introductionmentioning

confidence: 99%

Gd- and Pr-based double perovskite cobaltites as oxygen electrodes for proton ceramic fuel cells and electrolyser cells

et al. 2015

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Section: Introductionmentioning

confidence: 99%

Gd- and Pr-based double perovskite cobaltites as oxygen electrodes for proton ceramic fuel cells and electrolyser cells

et al. 2015

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“…A-site deficiency in the LSCF perovskite structure is a strategy to inhibit La and Sr diffusion preventing the formation of insulating compounds. 15,33 Svarkova et al 34 showed that the transformation of the cubic BSCF structure into hexagonal could be suppressed through appropriate cation substitution. Actually, Kim et al 35 confirmed that the excellent activity of BSCF is maintained over time by partial substitution of La for Ba (up to 950 h at 973 K), due to an improved stability of the cubic structure; Gasparyan et al 25 found that by doping B site with Mo significantly improves BSCF stability; and, in both cases, a minimum decrease in oxygen activity with respect to undoped BSCF was adduced.…”

mentioning

confidence: 99%

Infiltration, Overpotential and Ageing Effects on Cathodes for Solid Oxide Fuel Cells: La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δversus Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ

Giuliano

Carpanese

Clematis

et al. 2017

J. Electrochem. Soc.

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The two half-cell systems were compared to evaluate the influence of infiltration, overpotential and ageing on their performance and stability. Structure, microstructure and chemical composition were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) coupled with Energy Dispersive X-ray spectroscopy (EDX), whereas redox behavior was evaluated through temperature programmed reduction (TPR) and thermal gravimetric analysis (TGA) in combination with electrochemical impedance spectroscopy (EIS), which was also used to test the electrochemical performance. A decrease of polarization resistance for both infiltrated electrodes, compared to the reference ones, was highlighted at open circuit voltage (OCV), although the BSCF-based cathode was more benefitted more from infiltration than the LSCF-based one. Moreover, the application of cathodic overpotentials (−0.1 to −0.3 V) resulted in opposite effects on the LSCF-and BSCF-based cathodes, highlighting a different response of the oxygen vacancies to the applied voltage for the two perovskite compositions. The positive effect of the LSM layer was further confirmed by the observed improvement in long-term stability of both infiltrated perovskite-type systems. 1 They exhibit mixed ionic and electronic conductivity, with excellent charge and mass transfer properties 2 and high oxygen exchange surface coefficients. 3 Their excellent activity for oxygen reduction has been proved widely. [4][5][6][7][8][9][10] Although the structure and electrochemical processes of LSCF and BSCF are quite different, both of them have long-term stability and redox behavior issues to be clarified, in order to be used as cathode materials in commercial devices. Indeed, when used as cathodes in intermediate-temperatures solid oxide fuel cells (IT-SOFCs), they suffer from chemical and structural instability, which causes degradation during operation time. Moreover, the correlation between their redox behavior under electrochemical operating conditions is still unclear. Many studies have been devoted to investigating LSCF degradation and several causes have been reported, among them: i) mutual cations diffusion between interfaces with consequent atoms depletion and phase separation, [11][12][13][14][15][16] ii) LSCF grain coarsening, 17 iii) reactivity with YSZ-based electrolytes, even with ceria-based barrier layer, 18 iv) impurity contamination, namely Cr from metal interconnects and B from sealing when the cell is inside a stack.19-21 Some recent work performed on an LSCF/CGO (Ce 0.9 Gd 0.1 O 2-δ ) composite cathode on a YSZ electrolyte with a CGO barrier layer 11 affirms that Sr depletion, phase separation and cations inter-diffusion occur mainly during the fabrication process, with negligible contributions during long-term * Electrochemical Society Member.e Present Address: R&D Manufacturing Support Dept., Ansaldo Energia, Via Nicola Lorenzi 8, I-16152 Genoa. z E-mail: carpanese@unige.it operation (973 K). On the other hand, some previous works conversely found that LS...

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“…However, as a result of some decomposition of the bulk phase and a tiny surface segregation at 850°C, there is a very slow decrease on the oxygen permeation flux in the 1000 h operation [17]. However, in a medium temperature window between 500 and 800°C, stability problems are reported for BSCF [17,[20][21][22][23][24][25][26][27]. At these temperatures, the cubic BSCF phase decomposes partially in a cobalt-rich hexagonal Ba 0.5±0.1 Sr 0.5±0.1 CoO 3Àd and in a cobaltrich trigonal phase [23,25,26].…”

Section: Development Of Opm Materialsmentioning

confidence: 99%

“…However, in a medium temperature window between 500 and 800°C, stability problems are reported for BSCF [17,[20][21][22][23][24][25][26][27]. At these temperatures, the cubic BSCF phase decomposes partially in a cobalt-rich hexagonal Ba 0.5±0.1 Sr 0.5±0.1 CoO 3Àd and in a cobaltrich trigonal phase [23,25,26]. These new phases are known as poor oxygen conductors, further the materials became mechanically decomposed because of a volume expansion [28].…”

Section: Development Of Opm Materialsmentioning

confidence: 99%

Dense ceramic oxygen permeable membranes and catalytic membrane reactors

Wei

Yang

Caro

et al. 2013

Chemical Engineering Journal

180

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Decomposition pathway of cubic Ba0.5Sr0.5Co0.8Fe0.2O3−δ between 700°C and 1000°C analyzed by electron microscopic techniques

Cited by 58 publications

References 36 publications

Gd- and Pr-based double perovskite cobaltites as oxygen electrodes for proton ceramic fuel cells and electrolyser cells

Gd- and Pr-based double perovskite cobaltites as oxygen electrodes for proton ceramic fuel cells and electrolyser cells

Infiltration, Overpotential and Ageing Effects on Cathodes for Solid Oxide Fuel Cells: La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δversus Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ

Dense ceramic oxygen permeable membranes and catalytic membrane reactors

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Decomposition pathway of cubic Ba0.5Sr0.5Co0.8Fe0.2O3−δ between 700°C and 1000°C analyzed by electron microscopic techniques

Cited by 58 publications

References 36 publications

Gd- and Pr-based double perovskite cobaltites as oxygen electrodes for proton ceramic fuel cells and electrolyser cells

Gd- and Pr-based double perovskite cobaltites as oxygen electrodes for proton ceramic fuel cells and electrolyser cells

Infiltration, Overpotential and Ageing Effects on Cathodes for Solid Oxide Fuel Cells: La0.6Sr0.4Co0.2Fe0.8O3-δversus Ba0.5Sr0.5Co0.8Fe0.2O3-δ

Dense ceramic oxygen permeable membranes and catalytic membrane reactors

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Product

Resources

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Infiltration, Overpotential and Ageing Effects on Cathodes for Solid Oxide Fuel Cells: La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δversus Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ