| 1. |
- Zhu, Bin, 1956-, et al.
(författare)
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A new energy conversion technology joining electrochemical and physical principles
- 2012
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Ingår i: RSC Advances. - 2046-2069. ; 2:12, s. 5066-5070
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Tidskriftsartikel (refereegranskat)abstract
- We report a new energy conversion technology joining electrochemical and physical principles. This technology can realize the fuel cell function but built on a different scientific principle. The device consists of a single component which is a homogenous mixture of ceria composite with semiconducting materials, e.g. LiNiCuZn-based oxides. The test devices with hydrogen and air operation delivered a power density of 760mWcm(-2) at 550 degrees C. The device has demonstrated a multi-fuel flexibility and direct alcohol and biogas operations have delivered 300-500 mW cm(-2) at the same temperature. Device physics reveal a key principle similar to solar cells realizing the function based on an effective separation of electronic and ionic conductions and phases within the single-component. The component material multi-functionalities: ion and semi-conductions and bi-catalysis to H-2 or alcohol (methanol and ethanol) and air (O-2) enable this device realized as a fuel cell.
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| 2. |
- Abbas, Ghazanfar, et al.
(författare)
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Study of CuNiZnGdCe-Nanocomposite Anode for Low Temperature SOFC
- 2012
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Ingår i: Nanoscience and Nanotechnology Letters. - : American Scientific Publishers. - 1941-4900 .- 1941-4919. ; 4:4, s. 389-393
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Tidskriftsartikel (refereegranskat)abstract
- Composite electrodes of Cu0.16Ni0.27Zn0.37Ce0.16Gd0.04 (CNZGC) oxides have been successfully synthesized by solid state reaction method as anode material for low temperature solid oxide fuel cell (LTSOFC). These electrodes are characterized by XRD followed by sintering at various time periods and temperatures. Particle size of optimized composition was calculated 40-85 nm and sintered at 800 degrees C for 4 hours. Electrical conductivity of 4.14 S/cm was obtained at a temperature of 550 degrees C by the 4-prob DC method. The activation energy was calculated 4 x 10(-2) eV at 550 degrees C. Hydrogen was used as fuel and air as oxidant at anode and cathode sides respectively. I-V/I-P curves were obtained in the temperature range of 400-550 degrees C. The maximum power density was achieved for 570 mW/cm(2) at 550 degrees C.
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| 3. |
- Fan, Liangdong, 1985-, et al.
(författare)
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High performance transition metal oxide composite cathode for low temperature solid oxide fuel cells
- 2012
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 203:1, s. 65-71
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Tidskriftsartikel (refereegranskat)abstract
- Low temperature solid oxide fuel cells (SOFCs) with metal oxide composite cathode on the ceria–carbonate composite electrolyte have shown promising performance. However, the role of individual elements or compound is seldom investigated. We report here the effect of the ZnO on the physico-chemical and electrochemical properties of lithiated NiO cathode. The materials and single cells are characterized by X-ray diffraction, scanning electron microscopy, DC polarization electrical conductivity, electrochemical impedance spectroscopy and fuel cell performance. The ZnO modified lithiated NiO composite materials exhibit smaller particle size and lower electrical conductivity than lithiated NiO. However, improved electro-catalytic oxygen reduction activity and power output are achieved after the ZnO modification. A maximum power density of 808 mW cm−2 and the corresponding interfacial polarization resistance of 0.22 Ω cm2 are obtained at 550 °C using ZnO modified cathode and 300 μm thick composite electrolyte. The single cell keeps reasonable stability over 300 min at 500 °C. Thus, ZnO modified lithiated NiO is a promising cathode candidate for low temperature SOFCs.
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| 4. |
- Fan, Liangdong, et al.
(författare)
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Low temperature ceramic fuel cells using all nano composite materials
- 2012
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Ingår i: Nano Energy. - : Elsevier BV. - 2211-2855. ; 1:4, s. 631-639
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Tidskriftsartikel (refereegranskat)abstract
- The shift to low operational temperature of solid oxide or ceramic fuel cells has induced many new concepts and novel technologies. In the present study, fuel cell assembled by all nano composite materials - NiO/Fe 2O 3-SDC anode, SDC-carbonate electrolyte and lithiated NiO/ZnO cathode - is investigated. A range of techniques, i.e., X-ray diffraction (XRD), Scanning electron microscopy (SEM) and electrochemical impedance spectroscopy as well as polarization measurements are employed to characterize the crystalline structures, morphologies and electrochemical properties of the synthesized nanocomposite materials and cells. Performance comparison is made between single cells with and without a pre-sintering process. Finally, single cell short term stability and thermo cycle behaviors are also examined. Combined the facile fabrication process, relative high performance and reasonable stability, the current all nanocomposite system may be a promising functional system for low temperature ceramic fuel cells.
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| 5. |
- Fan, Liangdong, et al.
(författare)
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Mixed ion and electron conductive composites for single component fuel cells : I. Effects of composition and pellet thickness
- 2012
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 217, s. 164-169
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Tidskriftsartikel (refereegranskat)abstract
- Electrochemical performances of single component fuel cells (SCFCs) based on mixed ion and electron conductors have been studied as a function of composition and pellet thickness by polarization curves and electrochemical impedance spectroscopy. The electronic conductor of LNCZO shows conductivities of 21.7 and 5.3 S cm(-1) in H-2 and in air, respectively. SCFC using 40 wt. % of LNCZO and 60 wt. % of ion conductive SDC-Na2CO3 with a thickness of 1.10 mm shows the highest power density of 0.35 W cm(-2) at 550 degrees C. The performance is correlated to the mixed conduction properties (ionic and electronic, p and n-type) and the microstructure of the functional SCFC layer.
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| 6. |
- Fan, Liangdong, 1985-, et al.
(författare)
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Pr2NiO4–Ag composite cathode for low temperature solid oxide fuel cells with ceria-carbonate composite electrolyte
- 2012
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Ingår i: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 37:24, s. 19388-19394
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Tidskriftsartikel (refereegranskat)abstract
- Pr2NiO4-Ag composite was synthesized and evaluated as cathode component for low temperature solid oxide fuel cells based on ceria-carbonate composite electrolyte. X-ray diffraction analysis reveals that the formation of a single phase K2NiF4-type structure occurs at 1000 °C and Pr2NiO4-Ag composite shows chemically compatible with the composite electrolyte. Symmetrical cells impedance measurements prove that Ag displays acceptable electrocatalytic activity toward oxygen reduction reaction at the temperature range of 500-600 °C. Single cells with Ag active component electrodes present better electrochemical performances than those of Ag-free cells. An improved maximum power density of 695 mW cm-2 was achieved at 600 °C using Pr 2NiO4-Ag composite cathode, with humidified hydrogen as fuel and air as the oxidant. Preliminary results suggest that Pr 2NiO4-Ag composite could be adopted as an alternative cathode for low temperature solid oxide fuel cells.
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| 7. |
- Fan, Liangdong, et al.
(författare)
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Proton and Oxygen Ionic Conductivity of Doped Ceria-Carbonate Composite by Modified Wagner Polarization
- 2012
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Ingår i: International Journal of Electrochemical Science. - 1452-3981. ; 7:9, s. 8420-8435
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Tidskriftsartikel (refereegranskat)abstract
- The impressive ionic conductivity and tunable conduction behaviors have made the ceria-carbonate composite an attractive electrolyte for low temperature ceramic fuel cells. However, the conduction mechanism is not yet well studied. In the present study, both proton and oxygen ion conductivity as well as the transport properties of samaria-doped ceria/ sodium-lithium-carbonate (denoted as SDCLN) composite are investigated by the fuel cell study and the modified Hebb-Wagner polarization measurements. The multi-ionic polarization behaviors and the transfer processes in composite electrolyte under external electrical field are analyzed. A maximum power density of 780 mW cm(-2) and a calculated total ion (proton and oxygen ion) conductivity of 0.153 S cm(-1) are obtained under H-2/air condition at 550 degrees C. The Wagner DC polarization measurements show that the proton conduction dominates the total ionic conductivity. A synergistic effect exists between the charge carriers in the doped ceria-carbonate composite system. An ideal interfacial conduction model is also proposed based on the obtained results.
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| 8. |
- Fan, Liangdong, 1985-, et al.
(författare)
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Study of Ceria-Carbonate Nanocomposite Electrolytes for Low-Temperature Solid Oxide Fuel Cells
- 2012
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Ingår i: Journal of Nanoscience and Nanotechnology. - : American Scientific Publishers. - 1533-4880 .- 1533-4899. ; 12:6, s. 4941-4945
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Tidskriftsartikel (refereegranskat)abstract
- Composite and nanocomposite samarium doped ceria-carbonates powders were prepared by solidstatereaction, citric acid-nitrate combustion and modified nanocomposite approaches and used aselectrolytes for low temperature solid oxide fuel cells. X-ray Diffraction, Scanning Electron Microscope,low-temperature Nitrogen Adsorption/desorption Experiments, Electrochemical ImpedanceSpectroscopy and fuel cell performance test were employed in characterization of these materials.All powders are nano-size particles with slight aggregation and carbonates are amorphous incomposites. Nanocomposite electrolyte exhibits much lower impedance resistance and higher ionicconductivity than those of the other electrolytes at lower temperature. Fuel cell using the electrolyteprepared by modified nanocomposite approach exhibits the best performance in the whole operationtemperature range and achieves a maximum power density of 839 mW cm−2 at 600 C withH2 as fuel. The excellent physical and electrochemical performances of nanocomposite electrolytemake it a promising candidate for low-temperature solid oxide fuel cells.
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| 9. |
- Hong Li, Yu, et al.
(författare)
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Low doses of esmolol and phenylephrine act as diuretics during intravenous anesthesia
- 2012
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Ingår i: Critical Care. - : BioMed Central. - 1364-8535 .- 1466-609X. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- IntroductionThe renal clearance of infused crystalloid fluid is very low during anaesthesia and surgery, but experiments in conscious sheep indicate that the renal fluid clearance might approach a normal rate when the adrenergic balance is modified.MethodsSixty females (mean age, 32 years) undergoing laparoscopic gynecological surgery were randomized to control group and received only the conventional anesthetic drugs and 20 ml/kg of lactated Ringer's over 30 mins. The others were also given an infusion of 50 μg/kg/min of esmolol (beta1-receptor blocker) or 0.01 μg/kg/min of phenylephrine (alpha1-adrenergic agonist) over 3 hours. The distribution and elimination of infused fluid were studied by volume kinetic analysis based on urinary excretion and blood hemoglobin level.ResultsBoth drugs significantly increased urinary excretion while heart rate and arterial pressure remained largely unaffected. The urine flows during non-surgery were 43, 147, and 176 ml in the control, esmolol, and phenylephrine groups, respectively (medians, P < 0.03). When surgery had started the corresponding values were 34, 65 and 61 ml (P < 0.04). At 3 hours, averages of 9%, 20%, and 25% of the infused volume had been excreted in the three groups (P < 0.01). The kinetic analyses indicated that both treatments slowed down the distribution of fluid from the plasma to the interstitial fluid space, thereby preventing hypovolemia.ConclusionsEsmolol doubled and phenylephrine almost tripled urinary excretion during anesthesia-induced depression of renal fluid clearance.
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| 10. |
- Jing, Yifu, et al.
(författare)
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Synthesis and electrochemical performances of linicuzn oxides as anode and cathode catalyst for low temperature solid oxide fuel cell
- 2012
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Ingår i: Journal of Nanoscience and Nanotechnology. - : American Scientific Publishers. - 1533-4880 .- 1533-4899. ; 12:6, s. 5102-5105
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Tidskriftsartikel (refereegranskat)abstract
- Low temperature solid oxide fuel cell (LTSOFC, 300-600 °C) is developed with advantages compared to conventional SOFC (800-1000 °C). The electrodes with good catalytic activity, high electronic and ionic conductivity are required to achieve high power output. In this work, a LiNiCuZn oxides as anode and cathode catalyst is prepared by slurry method. The structure and morphology of the prepared LiNiCuZn oxides are characterized by X-ray diffraction and field emission scanning electron microscopy. The LiNiCuZn oxides prepared by slurry method are nano Li 0.28Ni 0.72O, ZnO and CuO compound. The nano-crystallites are congregated to form ball-shape particles with diameter of 800-1000 nm. The LiNiCuZn oxides electrodes exhibits high ion conductivity and low polarization resistance to hydrogen oxidation reaction and oxygen reduction reaction at low temperature. The LTSOFC using the LiNiCuZn oxides electrodes demonstrates good cell performance of 1000 mW cm -2 when it operates at 470 °C. It is considered that nano-composite would be an effective way to develop catalyst for LTSOFC.
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