| 1. |
- Benamira, M., et al.
(författare)
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Behaviour of Gadolinia-doped ceria mixed with alkali carbonates in view of SOFC applications
- 2009
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Ingår i: EFC 2009 - Piero Lunghi Conference, Proceedings of the 3rd European Fuel Cell Technology and Applications Conference. - 9788882862114 ; , s. 197-198
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Konferensbidrag (refereegranskat)abstract
- Composite materials based on mixtures of gadolinia-doped ceria and alkali carbonate salts were developed and analyzed for their use as electrolyte materials in low-temperature solid oxide fuel cells (LT-SOFCs). Cycling and ageing studies showed a good chemical stability of the composite material. A high and stable conductivity value (0,66 S.cm-1) was obtained all over a test of about 1600 hours at 600°C.
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| 2. |
- Benamira, M., et al.
(författare)
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Gadolinia-doped ceria mixed with alkali carbonates for SOFC applications : II - An electrochemical insight
- 2012
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Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 37:24, s. 19371-19379
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Tidskriftsartikel (refereegranskat)abstract
- Composite materials based on gadolinia-doped ceria (GDC) and alkali carbonates (Li2CO3-K2CO3 or Li2CO3-Na2CO3) are potential electrolytes for low temperature solid oxide fuel cell applications (LTSOFC). This paper completes a first one dedicated to the thermal, structural and morphological study of such compounds; it is fully focussed on their electrical/electrochemical properties in different conditions, temperature, composition and gaseous atmosphere (oxidative or reductive). The influence of the gaseous composition on the Arrhenius conductivity plots is evidenced, in particular under hydrogen atmosphere. Finally, electrical conductivity determined by impedance spectroscopy is presented as a function of time to highlight the stability of such composites over 6000 h. First results on single cells showed performance at 600 degrees C of 60 mW cm(-2).
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| 3. |
- Benamira, M., et al.
(författare)
-
Gadolinia-doped ceria mixed with alkali carbonates for solid oxide fuel cell applications : I. A thermal, structural and morphological insight
- 2011
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 196:13, s. 5546-5554
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Tidskriftsartikel (refereegranskat)abstract
- Ceria-based composites are developed and considered as potential electrolytes for intermediate solid oxide fuel cell applications (ITSOFC). After giving a survey of the most relevant results in the literature, the structural, thermal and morphological properties of composite materials based on gadolinia-doped ceria (GDC) and alkali carbonates (Li2CO3-K2CO3 or Li2CO3-Na2CO3) are carefully examined. Thermal analyses demonstrate the stability of the composite with very low weight losses of both water and CO2 during thermal cycling and after 168 h ageing. High-temperature and room-temperature X-ray diffraction allowed determining the precise structure of the composite and its regular and reversible evolution with the temperature. The microstructure and morphology of electrolyte pellets, as observed by scanning electron microscopy (SEM), show two-well separated phases: nanocrystals of GDC and a well-distributed carbonate phase. Finally, electrical conductivity determined by impedance spectroscopy is presented as a function of time to highlight the stability of such composites over 1500h.
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| 4. |
- Benamira, M., et al.
(författare)
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Structural and Electrical Properties of Gadolinia-doped Ceria Mixed with Alkali Earth Carbonates for SOFC Applications
- 2007
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Ingår i: SOLID OXIDE FUEL CELLS 10 (SOFC-X), PTS 1 AND 2. - : The Electrochemical Society. - 9781566775540 ; , s. 2261-2268
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Konferensbidrag (refereegranskat)abstract
- The properties of composite materials based on mixtures of gadolinium-doped ceria (GDC) and Li(2)CO(3)-K(2)CO(3) are analyzed as potential SOFC electrolytes. In a temperature range higher than 500 degrees C, their ionic conductivity is significantly higher than for single GDC. Discontinuities were found in the conductivity Arrhenius diagram (sigma vs. 1/T) around the melting point of the carbonate mixture (490 degrees C), showing, at least partially, the contribution of molten carbonates. At this stage, precise mechanisms are still under analysis.
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| 5. |
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