| 1. |
- Afzal, Muhammad, et al.
(författare)
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Fabrication of novel electrolyte-layer free fuel cell with semi-ionic conductor (Ba0.5Sr0.5Co0.8Fe0.2O3-delta- Sm0.2Ce0.8O1.9) and Schottky barrier
- 2016
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Ingår i: Journal of Power Sources. - : Elsevier. - 0378-7753 .- 1873-2755. ; 328, s. 136-142
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Tidskriftsartikel (refereegranskat)abstract
- Perovskite Ba0.5Sr0.5Co0.8Fe0.2O3-delta (BSCF) is synthesized via a chemical co-precipitation technique for a low temperature solid oxide fuel cell (LTSOFC) (300-600 degrees C) and electrolyte-layer free fuel cell (EFFC) in a comprehensive study. The EFFC with a homogeneous mixture of samarium doped ceria (SDC): BSCF (60%:40% by weight) which is rather similar to the cathode (SDC: BSCF in 50%:50% by weight) used for a three layer SOFC demonstrates peak power densities up to 655 mW/cm(2), while a three layer (anode/ electrolyte/cathode) SOFC has reached only 425 mW/cm(2) at 550 degrees C. Chemical phase, crystal structure and morphology of the as-prepared sample are characterized by X-ray diffraction and field emission scanning electron microscopy coupled with energy dispersive spectroscopy. The electrochemical performances of 3-layer SOFC and EFFC are studied by electrochemical impedance spectroscopy (EIS). As-prepared BSCF has exhibited a maximum conductivity above 300 S/cm at 550 degrees C. High performance of the EFFC device corresponds to a balanced combination between ionic and electronic (holes) conduction characteristic. The Schottky barrier prevents the EFFC from the electronic short circuiting problem which also enhances power output. The results provide a new way to produce highly effective cathode materials for LTSOFC and semiconductor designs for EFFC functions using a semiconducting-ionic material.
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| 2. |
- Liu, Yanyan, et al.
(författare)
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Superionic Conductivity of Sm3+, Pr3+, and Nd3+ Triple-Doped Ceria through Bulk and Surface Two-Step Doping Approach
- 2017
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 9:28, s. 23614-23623
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Tidskriftsartikel (refereegranskat)abstract
- Sufficiently high oxygen ion conductivity of electrolyte is critical for good performance of low-temperature solid oxide fuel cells (LT-SOFCs). Notably, material conductivity, reliability, and manufacturing cost are the major barriers hindering LT-SOFC commercialization. Generally, surface properties control the physical and chemical functionalities of materials. Hereby, we report a Sm3+, Pr3+, and Nd3+ triple-doped ceria, exhibiting the highest ionic conductivity among reported doped-ceria oxides, 0.125 S cm(-1) at 600 degrees C. It was designed using a two-step wet-chemical coprecipitation method to realize a desired doping for Sm3+ at the bulk and Pr3+/Nd3+ at surface domains (abbreviated as PNSDC). The redox couple Pr3+ Pr4+ contributes to the extraordinary ionic conductivity. Moreover, the mechanism for ionic conductivity enhancement is demonstrated. The above findings reveal that a joint bulk and surface doping methodology for ceria is a feasible approach to develop new oxide-ion conductors with high impacts on advanced LT-SOFCs.
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| 3. |
- Lu, Yuzheng, et al.
(författare)
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Progress in Electrolyte-Free Fuel Cells
- 2016
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Ingår i: FRONTIERS IN ENERGY RESEARCH. - : FRONTIERS MEDIA SA. - 2296-598X. ; 4
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Forskningsöversikt (refereegranskat)abstract
- Solid oxide fuel cell (SOFC) represents a clean electrochemical energy conversion technology with characteristics of high conversion efficiency and low emissions. It is one of the most important new energy technologies in the future. However, the manufacture of SOFCs based on the structure of anode/electrolyte/cathode is complicated and time-consuming. Thus, the cost for the entire fabrication and technology is too high to be affordable, and challenges still hinder commercialization. Recently, a novel type of electrolyte-free fuel cell (EFFC) with single component was invented, which could be the potential candidate for the next generation of advanced fuel cells. This paper briefly introduces the EFFC, working principle, performance, and advantages with updated research progress. A number of key R&D issues about EFFCs have been addressed, and future opportunities and challenges are discussed.
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| 4. |
- Deng, Hui, et al.
(författare)
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An ionic conductor Ce0.8Sm0.2O2_(delta) (SDC) and semiconductor Sm0.5Sr0.5CoO3 (SSC) composite for high performance electrolyte-free fuel cell
- 2017
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Ingår i: International journal of hydrogen energy. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0360-3199 .- 1879-3487. ; 42:34, s. 22228-22234
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Tidskriftsartikel (refereegranskat)abstract
- An advanced electrolyte-free fuel cell (EFFC) was developed. In the EFFC, a composite layer made from a mixture of ionic conductor (Ce0.8Sm0.2O2_(delta), SDC) and semiconductor (Sm0.5Sr0.5CoO3, SSC) was adopted to replace the electrolyte layer. The crystal structure, morphology and electrical properties of the composite were characterized by X-ray diffraction analysis (XRD), scanning electron microscope (SEM), and electrochemical impedance spectrum (EIS). Various ratios of SDC to SSC in the composite were modulated to achieve balanced ionic and electronic conductivities and good fuel cell performances. Fuel cell with an optimum ratio of 3SDC:2SSC (wt.%) reached the maximum power density of 741 mW cm(-2) at 550 degrees C. The results have illuminated that the SDC-SCC layer, similar to a conventional cathode, can replace the electrolyte to make the EFFC functions when the ionic and electronic conductivities were balanced.
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| 5. |
- Fan, L., et al.
(författare)
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Role of carbonate phase in ceria-carbonate composite for low temperature solid oxide fuel cells : A review
- 2016
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Ingår i: International Journal of Energy Research. - : John Wiley & Sons. - 0363-907X .- 1099-114X.
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Tidskriftsartikel (refereegranskat)abstract
- Ceria-salt composites represent one type of promising electrolyte candidates for low temperature solid oxide fuel cells (LT-SOFCs), in which ceria-carbonate attracts particular attention because of its impressive ionic conductivity and unique hybrid ionic conduction behavior compared with the commonly used single-phase electrolyte materials. It has been demonstrated that the introduction of carbonate in these new ceria-based composite materials initiates multi new functionalities over single-phase oxide, which therefore needs a comprehensive understanding and review focus. In this review, the roles of carbonate in the ceria-carbonate composites and composite electrolyte-based LT-SOFCs are analyzed from the aspects of sintering aid, electrolyte densification reagent, electrolyte/electrode interfacial 'glue' and sources of super oxygen ionic and proton conduction, as well as the oxygen reduction reaction promoter for the first time. This summary remarks the significance of carbonate in the ceria-carbonate composites for low temperature, 300-600°C, SOFCs and related highly efficient energy conversion applications.
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| 6. |
- Hu, H. -Q, et al.
(författare)
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Research progress of single layer fuel cell
- 2017
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Ingår i: Xiandai Huagong/Modern Chemical Industry. - : China National Chemical Information Center. - 0253-4320. ; 37:2, s. 31-35 and 37
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Tidskriftsartikel (refereegranskat)abstract
- The definition, working principle and the superior performance of single layer fuel cell are briefly introduced. The latest achievement and research progress in this field are summarized, which lay a foundation for the next development of single layer fuel cell.
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| 7. |
- Mi, Youquan, et al.
(författare)
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Rare-earth oxide Li0.3Ni0.9Cu0.07Sr0.03O2-delta composites for advanced fuel cells
- 2017
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Ingår i: International journal of hydrogen energy. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0360-3199 .- 1879-3487. ; 42:34, s. 22214-22221
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Tidskriftsartikel (refereegranskat)abstract
- Recent development on electrolyte-free fuel cell (EFFC) holding the same function with the traditional solid oxide fuel cell (SOFC) but with a much simpler structure has drawn increasing attention. Herein, we report a composite of industrial grade rare-earth precursor for agriculture and Li0.3Ni0.9Cu0.07Sr0.03O2.a, (RE-LNCS) for EFFCs. Both structural and electrical properties are investigated on the composite. It reveals that the RE LNCS possesses a comparable ionic and an electronic conductivities, 0.11 S cm(-1) and 0.20 S cm(-1) at 550 degrees C, respectively. An excellent power output of 1180 mW cm(-2) has been achieved at 550 degrees C, which is much better than that of the conventional anode/electrolyte/cathode based SOFCs, only around 360 mW cm(-2) by using ionic conducting rare-earth material as the electrolyte. Engineering large size cells with active area of 25 cm(2) prepared by tape-casting and hot-pressing gave a power output up to 12 W. This work develops a new functional single layer composite material for EFFCs and further explores the device functions.
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| 8. |
- Wu, Y., et al.
(författare)
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Natural hematite ore composited with ZnO nanoneedles for energy applications
- 2018
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Ingår i: Composites Part B. - : Elsevier Ltd. - 1359-8368 .- 1879-1069. ; 137, s. 178-183
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Tidskriftsartikel (refereegranskat)abstract
- Natural hematite ore is used as a novel photocatalyst for visible photocatalyst and also for advanced fuel cell applications. The hematite was composited with needle-shaped ZnO via a hydrothermal approach. This hematite-based system exhibits excellent photodegradation for methelyene blue within 40 min when the hematite is hybridized with wurzite-structured ZnO under visible light irradiation. The hybrid heterojunction was characterized by the transmission electron microscopy, ultraviolet–visible diffuses reflectance spectra, cyclic voltammetry, and AC impedance spectroscopy. The photocatalytic activity of the heterojunction was evaluated by the photodegradation of MB dye. The high photocatalytic activity observed under visible light is discussed on basis of the coupling of the hybrid heterojunction band structure. On the other hand, hematite ore and its composites were also used for advanced fuel cells. At 550 °C, 182 mW cm−2 and 580 mW cm−2 were achieved for fuel cells using raw hematite and composite with ZnO as the electrolytes, respectively. The heterostructure energy band alignment is proposed. These results demonstrate that the natural composites for next-generation functional semiconductor-ionic materials can influence the multi-utilization of natural resources, thereby affecting the environment and energy sustainability.
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| 9. |
- Zhu, Binzhu, et al.
(författare)
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Fluoride-based electrolytes and their applications for intermediate temperature ceramic fuel cells
- 2005
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Ingår i: Fluorinated Materials for Energy Conversion. - : Elsevier. - 9780080444727 ; , s. 419-437
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter focuses on fluoride-based electrolytes and their applications for intermediate temperature ceramic fuel cells. Among all fuel cell (FC) technologies, the solid oxide fuel cell (SOFC) can utilize a number of different fuels. The conventional SOFCs use a ceramic electrolyte, e.g., yttria-stabilized zirconia (YSZ), and operate at high temperature, typically 1000°C. The high operating temperature puts very high demands on the materials and technology, which poses a major challenge for the further development of SOFCs into the market. For developing cost-effective SOFCs, much effort has been devoted to obtain a lower operating temperature. All these efforts have, however, limitations due to the deficiency of technology and the stability of the material. Ceramic fuel cells (CFCs) are sometimes used as a more general term for fuel cells based on ceramic materials, which have the desired properties. In the chapter, the focus is on possible proton and oxygen ion conduction in fluoride-based electrolytes that may be of interest for fundamental and applied research. Also, the focus is to develop new advanced CFCs for intermediate temperatures.
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