| 1. |
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| 2. |
- Zhu, Bin, et al.
(författare)
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Innovative solid carbonate-ceria composite electrolyte fuel cells
- 2001
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Ingår i: Electrochemistry communications. - 1388-2481 .- 1873-1902. ; 3:10, s. 566-571
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Tidskriftsartikel (refereegranskat)abstract
- An innovative solid carbonate-oxide composite and related fuel cell (FC) technology is reported, It was discovered that solid carbonate-ceria composite (SCC) electrolytes were highly conductive with the material conductivity level varying from 0.001 to 0.2 S cm(-1) between 400 and 600 degreesC, and related FCs reached a power density between 200 and 600 mW cm(2) at a Current density of 300-1200 mA cm(-2) in the same temperature region. The SCCs were discovered to possess both oxide-ion (originating from the ceria phase) and proton (from the carbonate phase) conduction. Being an all-solid ceramic FC. the SCC can effectively reduce the material corrosion problem that is serious for the molten carbonate fuel cells (MCFCs). On the other hand, the innovative FC technology based on the SCC electrolytes developed in this work is similar to solid oxide fuel cells (SOF'Cs) and different from the MCFCs based on their ionic transport and FC processes, which facilitates a development of new type of advanced FC technology.
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| 3. |
- Zhu, Bin, et al.
(författare)
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Innovative low temperature SOFCs and advanced materials
- 2003
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Ingår i: Journal of Power Sources. - 0378-7753 .- 1873-2755. ; 118:02-jan, s. 47-53
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Tidskriftsartikel (refereegranskat)abstract
- High ionic conductivity, varying from 0.01 to 1 S cm(-1) between 300 and 700 degreesC, has been achieved for the hybrid and nano-ceriacomposite electrolyte materials, demonstrating a successful application for advanced low temperature solid oxide fuel cells (LTSOFCs). The LTSOFCs were constructed based on these new materials. The performance of 0.15-0.25 W cm(-2) was obtained in temperature region of 320400 degreesC for the ceria-carbonate composite electrolyte, and of 0.35-0.66 W cm(-2) in temperature region of 500-600 degreesC for the ceria-lanthanum oxide composites. The cell could even function at as low as 200 degreesC. The cell has also undergone a life test for several months. A two-cell stack was studied, showing expected performance successfully. The excellent LTSOFC performance is resulted from both functional electrolyte and electrode materials. The electrolytes are two phase composite materials based on the oxygen ion and proton conducting phases, or two rare-earth oxides. The electrodes used were based on the same composite material system having excellent compatibility with the electrolyte. They are highly catalytic and conductive thus creating the excellent performances at low temperatures. These innovative LT materials and LTSOFC technologies would open the door for wide applications, not only for stationary but also for mobile power sources.
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| 4. |
- Fu, Q. X., et al.
(författare)
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Doped ceria-chloride composite electrolyte for intermediate temperature ceramic membrane fuel cells
- 2002
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Ingår i: Materials letters (General ed.). - 0167-577X .- 1873-4979. ; 53:3, s. 186-192
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Tidskriftsartikel (refereegranskat)abstract
- A kind of oxide-salt composite electrolyte, gadolinium-doped ceria (GDC)-LiCl-SrCl2, prepared with hot-press technique, shows superior ionic conductivity, which is 2-10 times higher than that of GDC itself at the temperature range of 400-600 degreesC. More interestingly, not like the GDC electrolyte, which has some extent of electronic conduction under reducing atmosphere, the composite electrolyte is almost a pure ionic conductor, evidenced by the fuel cell's (FC) open circuit voltage (OCV) close to the theoretical one. The fuel cells based on this composite electrolyte show excellent power density output even at temperature as low as 500 degreesC (240 mW cm(-2)) in spite of the relatively thick electrolyte (0.4 mm). Such high performance, in combination with its low cost in both raw materials and fabrication process, make this kind of composite electrolyte a good candidate electrolyte material for future ultra-low-cost intermediate temperature ceramic membrane fuel cells (IT-CMFCs).
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| 5. |
- Fu, Q. X., et al.
(författare)
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Intermediate temperature fuel cells based on doped ceria-LiCl-SrCl2 composite electrolyte
- 2002
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Ingår i: Journal of Power Sources. - 0378-7753 .- 1873-2755. ; 104:1, s. 73-78
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Tidskriftsartikel (refereegranskat)abstract
- A new type of oxide-salt composite electrolyte, gadolinium-doped ceria (GDC)-LiCl-SrCl2, was developed and demonstrated its promising use for intermediate temperature (400-700 degreesC) fuel cells (ITFCs). The dc electrical conductivity of this composite electrolyte (0.09-0.13 S cm(-1) at 500-650 degreesC) was 3-10 times higher than that of the pure GDC electrolyte, indicating remarkable proton or oxygen ion conduction existing in the LiCl-SrCl2 chloride salts or at the interface between GDC and the chloride salts. Using this composite electrolyte, peak power densities of 260 and 510 mW cm(-2), with current densities of 650 and 1250 mA cm(-2) were achieved at 550 and 625 degreesC, respectively. This makes the new material a good candidate electrolyte for future low-cost ITFCs.
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| 6. |
- Kiros, Yohannes, et al.
(författare)
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Cost-effective perovskite for intermediate temperature solid oxide fuel cells (ITSOFC)
- 2001
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Ingår i: Journal of New Materials for Electrochemical Systems. - 1480-2422. ; 4:4, s. 253-258
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Tidskriftsartikel (refereegranskat)abstract
- Low lanthanum containing perovskite, Ca0.9La0.1MnO3 (CLM) was synthesized. The material was characterized and examined as a cathode for the intermediate temperature (400 to 650C) solid oxide fuel cell (ITSOFC) applications. ITSOFCs using this cost-effective perovskite as a cathode displayed an excellent cell performance: between 300 and 1500 mA/cm(-2) (100 to 500 mWcm(-2)) for temperatures ranging from 450 to 600 degreesC. The role of AgO as additive to the perovskite has also showed an enhancement in the fuel cell performance.
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| 7. |
- Yuan, J., et al.
(författare)
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Modeling and analysis of A bio-fuelled ceramic fuel cell stack
- 2004
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Ingår i: Fuel Cell Science, Engineering and Technology - 2004. - : ASMEDC. ; , s. 453-459
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Konferensbidrag (refereegranskat)abstract
- Recent development in the advanced ceramic fuel cell (CFC), working at intermediate temperature 600-700°C, brings up feasibility and new opportunity to employ renewable fuels with this innovative technology. It may offer a better solution concerning environment, natural resources and development of our civil society. Moreover, direct oxidation of hydrocarbon fuels at intermediate temperature possesses great advantage in avoiding complex and expensive external reforming process. This paper presents modeling and analysis of an inter-mediate temperature CFC stack. The model is a general one to evaluate the stack performance for the purpose of optimal design and/or configuration based on the specified electrical power or fuel supply rate, except that the Tafel coefficients are adjusted and/or obtained to match experimental data. The energy and gas flow data obtained from the investigation can be further used to identify the heat exchanger network configurations and optimal operating conditions using process integration techniques. The model can be applied as a stand alone one, or implemented into an overall energy system modeling for the purpose of system study.
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| 8. |
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| 9. |
- Zhu, Bin
(författare)
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Advantages of intermediate temperature solid oxide fuel cells for tractionary applications
- 2001
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Ingår i: Journal of Power Sources. - 0378-7753 .- 1873-2755. ; 93:02-jan, s. 82-86
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Tidskriftsartikel (refereegranskat)abstract
- Our recent achievements suggest that intermediate temperature (IT) solid oxide fuel cells (SOFCs) can become a strong competitor not only for stationary power generation, but also for tractionary applications, e.g. for electrical (hybrid) vehicles. These ITSOFCs are based on ceria-salt composite ceramic materials. These new ceria-based composite ceramic materials have shown a super ionic conductivity (0.1-1.0 S cm(-1)) in the IT region (400-600 degreesC). Using them as the electrolytes the ITSOFCs are operated between 300 and 1500 mA cm(-2) (200-700 mW cm(-2)) continuously between 400 and 600 degreesC. The opportunities and advantages of these new advanced ITSOFCs for electrical vehicle applications are discussed. The high efficiency ITSOFCs fed directly with hydrocarbon containing gas-type and liquid-type fuels have shown an enormous potential for application in electrical vehicles.
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| 10. |
- Zhu, Bin
(författare)
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Applications of hydrofluoride ceramic membranes for advanced fuel cell technology
- 2000
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Ingår i: International Journal of Energy Research. - 0363-907X .- 1099-114X. ; 24:1, s. 39-49
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Tidskriftsartikel (refereegranskat)abstract
- New types of materials, hydrofluoride-alumina ceramic composites containing one hydride component, CaH2, have been studied for fuel cell applications. Excellent fuel cell performances were achieved for a peak power density of 180 mW cm(-2) at 300 mA cm(-2), and a short-circuit current density near 1000 mA cm(-2). In fuel cell measurements the conductivity and ionic transport properties of the hydrofluoride-based electrolytes have also been investigated. During fuel cell operation, water was often observed at the cathode (air side), indicating that proton conduction occurs in these electrolyte materials. The experiments show an interesting chance for the future development of innovative fuel cell technology for commercialization.
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| 11. |
- Zhu, Bin, et al.
(författare)
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Calcium doped ceria-based materials for cost-effective intermediate temperature solid oxide fuel cells
- 2003
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Ingår i: Solid State Sciences. - : Elsevier BV. - 1293-2558 .- 1873-3085. ; 5:8, s. 1127-1134
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Tidskriftsartikel (refereegranskat)abstract
- This paper studies preparation and characterization of the calcium doping ceria (CCO) and carbonate composite materials. The material preparation was performed based on an oxalate co-precipitation. Various material characterizations were carried on the material phase structure based on XRD, TG/DSC and their fuel cell applications. The CCO materials showed a two-phase composite with very high ionic conductivity, 0.01 to 0.5 S cm(-1) between 400 and 700degreesC. Using the CCO-composites as the electrolytes for intermediate temperature solid oxide fuel cells (ITSOFC) a high performance, e.g., 600 mW cm(-2) was demonstrated at 600degreesC.
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| 12. |
- Zhu, Bin, et al.
(författare)
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Chemical stability study of Li2SO4 in a H2S/O-2 fuel cell
- 2000
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Ingår i: Solid State Ionics. - 0167-2738 .- 1872-7689. ; 127:02-jan, s. 83-88
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Tidskriftsartikel (refereegranskat)abstract
- Although H-2/O-2 fuel cells using Li2SO4 as the electrolyte have encountered problems in their chemical instability, the Li2SO4 electrolyte shows an excellent chemical stability under the operation conditions of a fuel cell using H2S as the fuel. Both thermodynamic analysis and experiments have demonstrated that it is feasible to develope practical H2S/O-2 fuel cells and co-generation devices based on the Li2SO4 electrolyte.
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| 13. |
- Zhu, Bin
(författare)
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Functional ceria-salt-composite materials for advanced ITSOFC applications
- 2003
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Ingår i: Journal of Power Sources. - 0378-7753 .- 1873-2755. ; 114:1, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports our current material research and development for advanced intermediate temperature (IT, 400-700 degreesC) solid oxide fuel cells (SOFCs). The materials reported in this work are based on ceria-salt-composites, which have super function, e.g. displaying ionic conductivity of 0.01-1 S cm(-1) in the IT region. They are functional ceramic materials for advanced ITSOFC applications. When these new composites are used as ITSOFC electrolytes, a performance of 300-800 mW cm(-2) between 400 and 650 degreesC has been demonstrated.
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| 14. |
- Zhu, Bin, et al.
(författare)
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Fundamental study on biomass-fuelled ceramic fuel cell
- 2002
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Ingår i: International Journal of Energy Research. - : Hindawi Limited. - 0363-907X .- 1099-114X. ; 26:1, s. 57-66
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Tidskriftsartikel (refereegranskat)abstract
- Recent development in the advanced intermediate temperature (400 to 700degreesC) ceramic fuel cell (CFC) research brings up feasibility and new opportunity to develop innovative biomass-fuelled CFC technology. This work focuses on fundamentals of the biomass-fuelled CFCs based on available biofuel resources through thermochemical conversion technologies. Both real producer gas from biomass gasification and imitative compounded gas were used as the fuel to operate the CFCs in the biomass CFC testing station. The composition of the fuel gas was varied in a wide range of practices of the present conversion technology both in KTH and Shandong Institute of Technology (SDIT), CFC performances were achieved between 100 and 700 mW cm(-2) at 600-800degreesC corresponding to various gas compositions. A high performance close to 400 mW cm(-2) was obtained at 600degreesC for the gas with the composition of H-2 (50 per cent) + CO (15 per cent) + CO2 (15 per cent) + N-2 (20 per cent) and more than 600 mW cm(-2) for the H-2 (55 per cent) + CO (28 per cent) + CO2 (17 per cent) at 700degreesC. This paper presents the experimental results and discusses the fundamentals and future potentiality on the biomass fuelled CFCs.
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| 15. |
- Zhu, Bin, et al.
(författare)
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Intermediate temperature fuel cells using alkaline and alkaline earth fluoride-based electrolytes
- 2000
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Ingår i: Solid State Ionics. - 0167-2738 .- 1872-7689. ; 135:04-jan, s. 503-512
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Tidskriftsartikel (refereegranskat)abstract
- Investigation of fuel cell applications using fluoride electrolytes, especially alkaline and alkaline earth fluorides, is a very new subject. Actually, most of the fluorides can function as fuel cell electrolytes, but the alkaline and alkaline earth fluorides are specially interesting since in composite materials they exhibit excellent performance for fuel cell electrolytes. Among the alkaline earth fluoride fuel cells, the best performance was achieved thus far for the fuel cell using the NaF-BaF2-Al2O3 electrolyte and LiNiO2 anode supported technique: it reached a power density of about 110 mW cm(-2) at a current density of 250 mA cm(-2) at 750 degreesC. Both proton and oxygen ionic conduction may exist in the alkaline earth fluorides since, during the fuel cell operation, water was observed at both the anode and the cathode, but, in most cases, water was formed at the cathode side mainly. Thus, proton conduction predominates, resulting in excellent fuel cell performances. A possible ionic transport mechanism is also discussed.
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| 16. |
- Zhu, Bin, et al.
(författare)
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LiF-CaH2 alumina electrolytes for intermediate temperature fuel cell applications
- 2000
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Ingår i: Electrochemistry communications. - 1388-2481 .- 1873-1902. ; 2:1, s. 10-14
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Tidskriftsartikel (refereegranskat)abstract
- Hydrofluoride-based electrolytes with proton conduction have been successfully used in intermediate: temperature fuel cell applications. Among the various hydrofluoride electrolytes, LiF-CaH2 and its composite with Al2O3, i.e., LiF-CaH2-Al2O3, are the most promising candidates which show more advantages than the other hydrofluorides. In this communication, we put our emphasis on the LiF-CaH2-Al2O3 electrolytes and their applications for intermediate temperature fuel cells. Furthermore, new fuel cell processes from hydride ions, H-, and the electrochemical behaviour of LiF-CaH2-Al2O3 electrolytes and fuel cells are discussed in more detail.
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| 17. |
- Zhu, Bin, et al.
(författare)
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LiF-MgF2 composite electrolyte for advanced ceramic fuel cells : structure, electrical properties and applications
- 2002
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Ingår i: Solid State Ionics. - 0167-2738 .- 1872-7689. ; 148:04-mar, s. 583-589
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Tidskriftsartikel (refereegranskat)abstract
- The two-phase composite, LiF-MgF2, has been discovered to have high ionic conductivity within a wide composition range, e.g., 10(-2)-10(-1) S cm(-1) at 600-800 degreesC, which is several orders of magnitude higher than that of pure LiF or MgF2. In addition, the activation energy of the composite is much lower than that of the pure phases. The remarkable conductivity enhancement as well as the low activation energy is attributed to the composite effect, i.e., the conduction takes place mainly in the interfacial region between LiF and MgF2 grains. The agreements of conductivity derived from two different methods, impedance spectra and fuel cell characterisation, in combination of the ESR results, show a possibility that proton (plus hydride ion) conduction dominates the electrical conduction in the LiF-MgF2 system under the H-2/air fuel cell environments.
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| 18. |
- Zhu, Bin
(författare)
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New generation or universal fuel cell system? R&D for intermediate temperature solid oxide fuel cells (ITSOFCs)
- 2001
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Ingår i: Journal of New Materials for Electrochemical Systems. - 1480-2422. ; 4:4, s. 239-251
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Tidskriftsartikel (refereegranskat)abstract
- Present challenges forfuel cell (FC) commercialisation are related to the material and system limitations, delaying the FC market. Most intensive interests currently for the FCs are concentrated on the polymer electroyte fuel cells (PEFCs) and solid oxide fuel cells (SOFCs). Due to the material constraint the SOFC system has to be operated at high temperature, e.g., 1000 degreesC, resulting in expensive SOFC system and complex technology; while the noble platinum catalyst has to be used for the PEFCs, creating a bottleneck for its commercialisation. In addition, the PEFC system has limited applications due to a shortage of the fuel flexibility, e.g., for hydrocarbon fuels, existing commonly in present fuel infrastructure. There is therefore a need to develop new generation or universal FC system, which can be employed for various applications for both mobile, e.g., electrical vehicles, and stationary, e.g., power generation plant. These request an advanced FC system that should possess of the wide fuel flexibility, i.e., fitting to various present hydrocarbon fiiels, and most importantly, this FC system should be cost-effective and marketable. However the present FC systems themselves alone are difficult to meet these demands due to the, material and system limitations. Our strategy is to develop a new advanced or near universal FC system to combine technological advantage from present FC systems to create a new competitive vis-a-vis FC technology. To realise this strategy a key issue is addressed from the material point of view., This paper thus reviews recent developments/progresses and achievements/applications for R&D on the materials and ITSOFCs, more concerned on the new material-based ITSOFCs.
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| 19. |
- Zhu, Bin, et al.
(författare)
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Novel hybrid conductors based on doped ceria and BCY20 for ITSOFC applications
- 2004
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Ingår i: Electrochemistry communications. - : Elsevier BV. - 1388-2481 .- 1873-1902. ; 6:4, s. 378-383
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Tidskriftsartikel (refereegranskat)abstract
- Ceria-based composites have been previously developed as functional electrolytes for high performance ITSOFC applications. These composites display hybrid proton and oxygen ion conduction. To meet demands for more functional hybrid proton and oxygen ion conductors we developed further composite electrolyte materials containing a proton conductor, BaCe0.8Y0.2O3-delta (BCY20), and an oxygen ion conductor, samarium doped ceria (SDC). The BCY20 and SDC composites were prepared based on composite technology using their starting powders produced via sol-gel and co-precipitation processes, respectively. Using the SDC-BCY20 composites as the electrolytes ITSOFCs were constructed using NiO-based composite anodes, silver-based cathodes. Applying hydrogen as the fuel, compressed air as the oxidant, the fuel cells were tested in the temperature region between 300 and 700 degreesC. The SDC-BCY20 electrolyte ITSOFCs reached a performance of 0.25 W/cm(2) at 550 degreesC. Under a constant discharge water was observed both, on the anode and the cathode side, indicative of hybrid conduction based on proton and oxygen ion transport. Initial experimental results showed that combining a proton with an oxygen ion conductor forming a novel hybrid ion conductor with promising applications for ITSOFCs was successful.
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| 20. |
- Zhu, Bin
(författare)
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Proton and oxygen ion conduction in nonoxide ceramics
- 2000
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Ingår i: Materials research bulletin. - 0025-5408 .- 1873-4227. ; 35:1, s. 47-52
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Tidskriftsartikel (refereegranskat)abstract
- By directly examining fuel cell performances, it was discovered that nonoxide containing materials such as chlorides and fluorides exhibit significant proton and oxygen ion conduction. Ionic transport measurements showed that both proton and oxygen ion conduction are present, with proton conduction predominant in most cases. Steady-state current output under fuel-cell operation indicates that the transport process in both chloride and fluoride electrolytes is dominated by the source ions, protons, and oxygen ions. These new materials have significant importance for both fundamental and applied research.
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| 21. |
- Zhu, Bin
(författare)
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Proton and oxygen ion-mixed-conducting ceramic composites and fuel cells
- 2001
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Ingår i: Solid State Ionics. - 0167-2738 .- 1872-7689. ; 145:04-jan, s. 371-380
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Tidskriftsartikel (refereegranskat)abstract
- This work focuses on the behaviour and role of protons and oxygen ions for the electrical properties of salt-oxide composites based on halides, more specifically on fluorides e.g. MFx (M = Li, Na. Ca, Ba, Sr, Mg. x = 1, 2)-based composites with oxides. The electrical properties were studied by using DC measurements, employing either gas concentration cell or fuel cell techniques. The conductivity of the fluoride-based composite electrolytes is 10(-3)-10(-2) S/cm at temperatures between 600 and 800 degreesC. Proton and oxygen ion defects, their generation and transport, showed a very strong dependence on the employed gas resources. Possessing both proton and oxygen ion conduction, on one hand, enhances the material total conductivity and, on the other hand, may promote the electrode reaction and the kinetics at two interfaces between the electrolyte and electrodes for fuel cells, thus, enhancing the cur-rent exchange rate and fuel cell performance. Using these composite electrolytes, a typical power density of 120-160 mW/cm(2) under a current density 300-800 mA/cm(2) was obtained in a fuel cell. Although both proton and oxygen ion conduction are possible, the proton defect concentration and related conduction generally predominate as the basic feature of the halide-based composite materials.
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| 22. |
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| 23. |
- Zhu, Bin, et al.
(författare)
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Transparent two-phase composite oxide thin films with high conductivity
- 2001
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Ingår i: Thin Solid Films. - 0040-6090 .- 1879-2731. ; 385:02-jan, s. 209-214
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Tidskriftsartikel (refereegranskat)abstract
- New types of transparent thin films based on CeO2-Al2O3 and -SiO2 and ion-doped CeO2 composite oxides have been developed by sol-gel process. The films have two phases: a host phase, CeO2 or ion-doped CeO2; and a guest phase Al2O3 or SiO2, so called binary composites. This is the unique character to distinguish from other transparent films, e.g. CeO2-SnO2, -TiO2 and -ZrO2 single phase (solid solution), for electrochromic applications. Film conductivity was determined by impedance analysis and electrochemical property was investigated by cyclic voltammetry. The conductivity of the composite films is in the range of 10(-2)-0.2 S/cm in the temperature range of 500-700 degreesC. Binary films containing 30% alumina and 50% silica with thickness 35 and 30 nm have the highest amount of charge exchange for 1.0 Li/Ce and 0.7 Li/Ce, respectively. After 380 cycles the charge capacity of the CeO2-Al2O3 reached about the same value as started in the beginning. The films show a high transmittance for visible light. Unusual properties for these composite thin films have been implemented due to the special thin film nano-structure and two-phase regions and interfaces, The ionic transport and insertion/extraction mechanisms in these new composite film materials are discussed based on a proposed physical model. These composite films have a broad application in various electrochemical devices, such as electrochromic and fuel cell devices.
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| 24. |
- Zhu, Bin
(författare)
-
- 2004
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Ingår i: Fuel Cell Science, Engineering and Technology - 2004. - : ASMEDC. ; , s. 409-417
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Konferensbidrag (refereegranskat)abstract
- Since many years in Swedish national research project and Swedish-Chinese research framework we have carried out advanced ceramic fuel cell research and development, targeting for intermediate and low temperature ceramic or solid oxide fuel cells (ILTCFCs or ILTSOFCs, 300-700°C) based on ceramic-based composite materials. The ceramic composite material developments in Sweden have been experienced from the oxyacid-salts oxide proton-based conductors, non-oxide containment salts, the ceria-based composite electrolytes and nano-composites. Among them the ceria-based composites showed excellent ionic conductivity of 0.01 to 1 Scm-1 and ILTCFCs using these composites as electrolytes have achieved high performances of 200 to 1000 mWcm-2 at temperatures between 400 and 700°C. The excellent ion conduction was resulted from hybrid proton and oxygen ion conduction. The hybrid ion conduction and dual electrode reactions and processes create a new fuel cell system. Advanced ceramic fuel cell aims at developing a new generation to realize the challenges for fuel cell commercialization. This paper reviews our more than 14 years R&D on the field with emphasis on the recent progresses and achievements.
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