| 1. |
- Hu, Huiqing, et al.
(författare)
-
Fabrication of electrolyte-free fuel cell with Mg0.4Zn0.6O/Ce0.8Sm0.2O2-delta-Li0.3Ni0.6Cu0.07Sr0.03O2-delta layer
- 2014
-
Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 248, s. 577-581
-
Tidskriftsartikel (refereegranskat)abstract
- Electrolyte-free fuel cell (EFFC) which holds the similar function with the traditional solid oxide fuel cell (SOFC) but possesses a completely different structure, has draw much attention during these years. Herein, we report a complex of MZSDC LNCS (Mg0.4Zn0.6O/Ce0.8Sm0.2O2-delta-Li0.3Ni0.6Cu0.07Sr0.03O2-delta) for EFFC that demonstrates a high electrochemical power output of about 600 mW cm(-2) at 630 degrees C. The co-doped MZSDC is synthesized by a co-precipitation method. Semiconductor material of LNCS is synthesized by direct solid state reaction. The microstructure and morphology of the composite materials are characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy-dispersive Xray spectrometer (EDS). The performance of the cell with a large size (6 x 6 cm(2)) is comparable or even better than that of the conventional solid oxide fuel cells with large sizes. The maximum power output of 9.28 W is obtained from the large-size cell at 600 degrees C. This paper develops a new functional nanocomposite for EFFC which is conducive to its commercial use.
|
|
| 2. |
- Hu, Huiging, et al.
(författare)
-
Time-dependent performance change of single layer fuel cell with Li0.4Mg0.3Zn0.3O/Ce0.8Sm0.2O2-delta composite
- 2014
-
Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 39:20, s. 10718-10723
-
Tidskriftsartikel (refereegranskat)abstract
- A Large-size engineering single layer fuel cell (SLFC) consisting of a nano-structured Li0.4Mg0.3Zn0.3O2-delta/Ce0.8Sm0.2O2-delta (LMZSDC) composite with an active area of 25 cm(2) (6 cm x 6 cm x 0.1 cm) is successfully fabricated. The SLFC is evaluated by testing the cell durability with a time-dependent degradation using an H-2 fuel and an air oxidant at 600 degrees C for over 120 h. A maximum power of 12.8 W (512 mW cm(-2)) is achieved at 600 degrees C. In the initial operation stage around 50 h, the cell's performance decreases from 12.8 to 11.2 W; however, after this point, the performance was consistently stable, and no significant degradation is observed in the current density or the cell performance. The device performed excellently at low temperatures with a delivered power output of more than 250 mW cm(-2) at a temperature as low as 400 degrees C. By curve fitting the X-ray photoelectron spectroscopy (XPS) results, the ratio of Ce3+/(Ce3++Ce4+) before and after the long-time operation is analyzed. The ratio increased from 28.2% to 31.4% in the electrolyte which indicates a reduction occurs in the beginning operation that causes an initial performance loss for the device power output and OCV. Electrochemical impedance analyses indicate that the LMZSDC had a high ionic transport, and the device had quick dynamic processes and, thus, a high fuel cell performance. The LMZSDC is a new type of ionic material that has been successfully applied to SLFCs.
|
|
| 3. |
- Qin, Haiying, et al.
(författare)
-
Direct biofuel low-temperature solid oxide fuel cells
- 2011
-
Ingår i: ENERGY & ENVIRONMENTAL SCIENCE. - : Royal Society of Chemistry (RSC). - 1754-5692 .- 1754-5706. ; 4:4, s. 1273-1276
-
Tidskriftsartikel (refereegranskat)abstract
- A low-temperature solid oxide fuel cell system was developed to use bioethanol and glycerol as fuels directly. This system achieved a maximum power density of 215 mW cm(-2) by using glycerol at 580 degrees C and produced a great impact on sustainable energy and the environment.
|
|
| 4. |
- Qu, Yanhua, 1974-, et al.
(författare)
-
Ground tit genome reveals avian adaptation to living at high altitudes in the Tibetan plateau.
- 2013
-
Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 4, s. 2071-
-
Tidskriftsartikel (refereegranskat)abstract
- The ground tit (Parus humilis) is endemic to the Tibetan plateau. It is a member of family Paridae but it was long thought to be related to the ground jays because of their morphological similarities. Here we present the ground tit's genome and re-sequence two tits and one ground jay, to clarify this controversially taxonomic status and uncover its genetic adaptations to the Tibetan plateau. Our results show that ground tit groups with two tits and it diverges from them between 7.7 and 9.9 Mya. Compared with other avian genomes, ground tit shows expansion in genes linked to energy metabolism and contractions in genes involved in immune and olfactory perception. We also found positively selected and rapidly evolving genes in hypoxia response and skeletal development. These results indicated that ground tit evolves basic strategies and 'tit-to-jay' change for coping with the life in an extreme environment.
|
|
| 5. |
- Tang, Z. G., et al.
(författare)
-
SDC-LiNa carbonate composite and nanocomposite electrolytes
- 2010
-
Ingår i: International Journal of Hydrogen Energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 35:7, s. 2970-2975
-
Tidskriftsartikel (refereegranskat)abstract
- Structural and A.C. impedance analyses were conducted for various ceria-based composite systems. Structural studies showed that the ceria-carbonate composites are two-phase materials, where carbonates were often amorphous. Two phases of ceria and carbonates are mixed at different particle size levels depending on the preparation techniques, especially, employing the NANOCOFC (nanocomposites for advanced fuel cell technology) approach to prepare ceria-LiNaCO3 nanocomposites. General observations from structural analyses are that different preparation techniques resulted in two-phase composite particles in different particle sizes varying from micrometer level to nano-level accompanying also different homogeneity. General observations from impedance analyses are that for the nanocomposites (particle size at nano-scale) more complex grain boundary interface effects are observed compared to that for samples with grains of the micrometer level, but nanocomposites showed enhanced conductivities at the low temperatures. Interfaces and interfacial conduction mechanism can be concluded for such conductivity enhancement. Crown Copyright (C) 2009 Published by Elsevier Ltd on behalf of Professor T. Nejat Veziroglu. All rights reserved.
|
|
| 6. |
- Zhu, Bin, 1956-, et al.
(författare)
-
A new energy conversion technology joining electrochemical and physical principles
- 2012
-
Ingår i: RSC Advances. - 2046-2069. ; 2:12, s. 5066-5070
-
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.
|
|
| 7. |
- Abbas, Ghazanfar, et al.
(författare)
-
Electrochemical study of nanostructured electrode for low-temperature solid oxide fuel cell (LTSOFC)
- 2014
-
Ingår i: International Journal of Energy Research. - : Hindawi Limited. - 0363-907X .- 1099-114X. ; 38:4, s. 518-523
-
Tidskriftsartikel (refereegranskat)abstract
- Zn-based nanostructured Ba0.05Cu0.25Fe0.10Zn0.60O (BCFZ) oxide electrode material was synthesized by solid-state reaction for low-temperature solid oxide fuel cell. The cell was fabricated by sandwiching NK-CDC electrolyte between BCFZ electrodes by dry press technique, and its performance was assessed. The maximum power density of 741.87 mW-cm(-2) was achieved at 550 degrees C. The crystal structure and morphology were characterized by X-ray diffractometer (XRD) and SEM. The particle size was calculated to be 25 nm applying Scherer's formula from XRD data. Electronic conductivities were measured with the four-probe DC method under hydrogen and air atmosphere. AC Electrochemical Impedance Spectroscopy of the BCFZ oxide electrode was also measured in hydrogen atmosphere at 450 degrees C.
|
|
| 8. |
- Abbas, Ghazanfar, et al.
(författare)
-
Preparation and characterization of nanocomposite calcium doped ceria electrolyte with alkali carbonates (NK-CDC) for SOFC
- 2010
-
Ingår i: ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology, FUELCELL 2010. - : ASME Press. - 9780791844052 ; , s. 427-432
-
Konferensbidrag (refereegranskat)abstract
- The entire world's challenge is to find out the renewable energy sources due to rapid depletion of fossil fuels because of their high consumption. Solid Oxide Fuel Cells (SOFCs) are believed to be the best alternative source which converts chemical energy into electricity without combustion. Nanostructured study is required to develop highly ionic conductive electrolyte for SOFCs. In this work, the calcium doped ceria (Ce0.8Ca0.2O 1.9) coated with 20% molar ratio of two alkali carbonates (CDC-M: MCO3, where M= Na and K) electrolyte was prepared by co-precipitation method in this study. Ni based electrode was used to fabricate the cell by dry pressing technique. The crystal structure and surface morphology was characterized by X-Ray Diffractometer (XRD), Scanning Electron Microscopy (SEM) and High Resolution Transmission Electron Microscopy (HRTEM). The particle size was calculated in the range of 10-20nm by Scherrer's formula and compared with SEM and TEM results. The ionic conductivity was measured by using AC Electrochemical Impedance Spectroscopy (EIS) method. The activation energy was also evaluated. The performance of the cell was measured 0.567W/cm2 at temperature 550°C with hydrogen as a fuel.
|
|
| 9. |
- Abbas, Ghazanfar, et al.
(författare)
-
Preparation and Characterization of Nanocomposite Calcium Doped Ceria Electrolyte With Alkali Carbonates (NK-CDC) for SOFC
- 2011
-
Ingår i: Journal of Fuel Cell Science and Technology. - : ASME International. - 1550-624X .- 1551-6989. ; 8:4, s. 041013-
-
Tidskriftsartikel (refereegranskat)abstract
- The entire world's challenge is to find out the renewable energy sources due to rapid depletion of fossil fuels because of their high consumption. Solid oxide fuel cells (SOFCs) are believed to be the best alternative source, which converts chemical energy into electricity without combustion. Nanostructure study is required to develop highly ionic conductive electrolytes for SOFCs. In this work, the calcium doped ceria (Ce0.8Ca0.2O1.9) coated with 20% molar ratio of two alkali carbonates (CDC-M: MCO3, where M = Na and K) electrolyte was prepared by coprecipitation method. Ni based electrode was used to fabricate the cell by dry pressing technique. The crystal structure and surface morphology were characterized by an X-ray diffractometer, scanning electron microscopy (SEM), and high resolution transmission electron microscopy (TEM). The particle size was calculated in the range 10-20 nm by Scherer's formula and compared with SEM and TEM results. The ionic conductivity was measured by using ac electrochemical impedance spectroscopy method. The activation energy was also evaluated. The performance of the cell was measured 0.567 W/cm(2) at temperature 550 degrees C with hydrogen as a fuel.
|
|
| 10. |
- Abbas, Ghazanfar, et al.
(författare)
-
Study of CuNiZnGdCe-Nanocomposite Anode for Low Temperature SOFC
- 2012
-
Ingår i: Nanoscience and Nanotechnology Letters. - : American Scientific Publishers. - 1941-4900 .- 1941-4919. ; 4:4, s. 389-393
-
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.
|
|
