| 1. |
- Behm, Mårten, et al.
(författare)
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Nickel as anode material for the electrochemical production of polysulfides in white liquor
- 1999
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Ingår i: Journal of New Materials for Electrochemical Systems. - 1480-2422. ; 2:1, s. 11-18
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Tidskriftsartikel (refereegranskat)abstract
- This paper is concerned with new anode materials for the electrochemical oxidation of white liquor. This electrosynthesis process is run in a membrane cell where polysulfide ions are produced in the white liquor of the anode chamber, while a pure sodium hydroxide solution is generated in the cathode chamber: If the noble metal oxide coated anodes that were used in a previous investigation could be successfully replaced by nickel, important reductions in investment costs would be possible. The stability and catalytic activity of nickel as anode material were investigated using cyclic voltammetry and chronoamperometry on rotating disc electrodes, combined with surface analysis. Furthermore, porous nickel was tested in a flow cell, with galvanostatic electrolysis. The results show that nickel has good activity for sulfide oxidation, but a nickel oxide/sulfide surface layer is formed which deactivates the electrode at E greater than or equal to -0.2 V, probably due to the increasing proportion of poorly conducting Ni(II) oxide. Carbon precipitation, and peeling of a thin film of the metal were observed with SEM. High current efficiency and an overpotential of less than 0.2 V were obtained with a porous nickel electrode at a geometric current density of 3 kA m(-2). Corrosion did not appear to be a problem, and nickel should also be suitable as substrate material for more active anode coatings.
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| 2. |
- 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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| 3. |
- Lundblad, Anders
(författare)
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Materials characterization of thin film electrodes for PEFC - Survey of methods and an example
- 2004
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Ingår i: Journal of New Materials for Electrochemical Systems. - 1480-2422. ; 7:1, s. 21-28
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Tidskriftsartikel (refereegranskat)abstract
- Thorough materials characterization is an essential tool for obtaining a deeper understanding of the electrochemical processes taking place in thin film electrodes of polymer fuel cells. This paper gives a survey of different methods for characterizing materials properties that are relevant to the electrochemical performance of such electrodes (i.e. loading, thickness, electrical conductivity, porosity, pore size distribution and pore morphology). The use of these materials characterization methods is exemplified, among other things it is shown that the ionomer (Nafion(R)) in a thin-film electrode made by the spraying method is homogeneously distributed in pores smaller than 40 nm. Furthermore, the ionomer penetrates and/or encapsulates the primary carbon particles of 30 nm. The results are discussed in relation to different MEA fabrication methods.
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| 4. |
- 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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