GDC-Y2O3 Oxide Based Two Phase Nanocomposite Electrolytes

2010 ◽  
Author(s):  
Rizwan Raza ◽  
Ghazanfar Abbas ◽  
Bin Zhu
Keyword(s):  
Fuel Cell ◽  
Electrochemical Impedance ◽  
Ionic Conductivities ◽  
Morphological Properties ◽  
Precipitation Method ◽  
Scanning Calorimetry ◽  
Two Phase ◽  
Nanocomposite Electrolyte ◽  
Scherrer Formula ◽  
Co Precipitation

An oxide based two phase nanocomposite electrolyte (Ce0.9Gd0.1O2) was synthesized by a co-precipitation method and coated with Yttrium oxide (Y2O3). The nanocomposite electrolyte showed the significant performance of power density 750mW/cm2 and higher conductivities at relatively low temperature 550°C. Ionic conductivities were measured with electrochemical impedance spectroscopy (EIS) and DC (4 probe method). The structural and morphological properties of the prepared electrolyte were investigated by means of High Resolution Scanning Electron Microscopy (HRSEM). The thermal stability was determined with Differential Scanning Calorimetry (DSC). The particle size was calculated with Scherrer formula and compare with SEM results, 15–20 nm is in a good agreement with the SEM and X-ray diffraction (XRD) results. The purpose of the study to introduce the functional nanocomposite materials, for advanced fuel cell technology (NANOCOFC) to meet the challenges of solid oxide fuel cell (SOFC).

GDC - Y 2 O 3 Oxide Based Two Phase Nanocomposite Electrolyte

2011 ◽  
Vol 8 (4) ◽  
Author(s):  
Rizwan Raza ◽  
Ghazanfar Abbas ◽  
S. Khalid Imran ◽  
Imran Patel ◽  
Bin Zhu
Keyword(s):  
Fuel Cell ◽  
Ionic Conductivities ◽  
Morphological Properties ◽  
Scanning Calorimetry ◽  
Two Phase ◽  
Composite Electrolyte ◽  
Significant Performance ◽  
Advanced Fuel ◽  
Nanocomposite Electrolyte ◽  
Scherrer Formula

Oxide based two phase composite electrolyte (Ce0.9Gd0.1O2–Y2O3) was synthesized by coprecipitation method. The nanocomposite electrolyte showed the significant performance of power density 785 mW cm−2 and higher conductivities at relatively low temperature 550°C. Ionic conductivities were measured with ac impedance spectroscopy and four-probe dc method. The structural and morphological properties of the prepared electrolyte were investigated by scanning electron microscope (SEM). The thermal stability was determined with differential scanning calorimetry. The particle size that was calculated with Scherrer formula, 15–20 nm, is in a good agreement with the SEM and X- ray diffraction results. The purpose of this study is to introduce the functional nanocomposite materials for advanced fuel cell technology to meet the challenges of solid oxide fuel cell.

scholarly journals Phase Transition and Coefficients of Thermal Expansion in Al2−xInxW3O12 (0.2 ≤ x ≤ 1)

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4021
Author(s):  
Andrés Esteban Cerón Cerón Cortés ◽  
Anja Dosen ◽  
Victoria L. Blair ◽  
Michel B. Johnson ◽  
Mary Anne White ◽  
...  
Keyword(s):  
Phase Transition ◽  
Thermal Expansion ◽  
Thermal Shock ◽  
Monoclinic Phase ◽  
Ceramic Materials ◽  
Precipitation Method ◽  
Scanning Calorimetry ◽  
Orthorhombic Crystal ◽  
Co Precipitation

Materials from theA2M3O12 family are known for their extensive chemical versatility while preserving the polyhedral-corner-shared orthorhombic crystal system, as well as for their consequent unusual thermal expansion, varying from negative and near-zero to slightly positive. The rarest are near-zero thermal expansion materials, which are of paramount importance in thermal shock resistance applications. Ceramic materials with chemistry Al2−xInxW3O12 (x = 0.2–1.0) were synthesized using a modified reverse-strike co-precipitation method and prepared into solid specimens using traditional ceramic sintering. The resulting materials were characterized by X-ray powder diffraction (ambient and in situ high temperatures), differential scanning calorimetry and dilatometry to delineate thermal expansion, phase transitions and crystal structures. It was found that the x = 0.2 composition had the lowest thermal expansion, 1.88 × 10−6 K−1, which was still higher than the end member Al2W3O12 for the chemical series. Furthermore, the AlInW3O12 was monoclinic phase at room temperature and transformed to the orthorhombic form at ca. 200 °C, in contrast with previous reports. Interestingly, the x = 0.2, x = 0.4 and x = 0.7 materials did not exhibit the expected orthorhombic-to-monoclinic phase transition as observed for the other compositions, and hence did not follow the expected Vegard-like relationship associated with the electronegativity rule. Overall, compositions within the Al2−xInxW3O12 family should not be considered candidates for high thermal shock applications that would require near-zero thermal expansion properties.

Synthesis of Silica Modified Large-Sized Hydroxyapatite Whiskers by a Hydrothermal Co-Precipitation Method

2015 ◽  
Vol 645-646 ◽  
pp. 1339-1344 ◽  
Author(s):  
Yan Ting Yin ◽  
Qing Hua Chen ◽  
Ting Ting Yan ◽  
Qing Hua Chen
Keyword(s):  
Bone Repair ◽  
Ethanol Solution ◽  
Morphological Properties ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Type ◽  
Ft Ir ◽  
Co Precipitation ◽  
Surface Modified

The objective of this study was to develop a novel silica modified large-sized hydroxyapatite whiskers with improved properties for use in bone repair applications. Large-sized whiskers with a mean length of 250μm were obtained by a hydrothermal co-precipitation method at 150°C, 7.5Mpa in high-pressure reactor. Silica modified hydroxyapatite whiskers were prepared by dissolving TEOS in ethanol solution, then sintering with hydroxyapatite. The compositional and morphological properties of prepared whiskers were studied by means of x-ray diffraction (XRD), Fouier transform infrared (FT-IR), scanning electron microscopy (SEM). The results indicated the evidence of nanosilicon dioxide particles on the surface of HAP whiskers. The size of nanosilicon dioxide particles depends on dropping and stirring rate. Hence, this new type of silica modified large-sized hydroxyapatite whiskers is a valuable candidate for biomedical applications.Key words: hydroxyapatite, hydrothermal co-precipitation, surface modified, whiskers

Preparation and Characterization of Nanocomposite Calcium Doped Ceria Electrolyte With Alkali Carbonates (NK-CDC) for SOFC

2010 ◽  
Author(s):  
Ghazanfar Abbas ◽  
Rizwan Raza ◽  
Muhammad Ashraf Chaudhry ◽  
Bin Zhu
Keyword(s):  
Electron Microscopy ◽  
Fossil Fuels ◽  
Electrochemical Impedance ◽  
Renewable Energy Sources ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Doped Ceria ◽  
Alternative Source ◽  
Calcium Doped ◽  
Co Precipitation

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 (Ce0.8Ca0.2O1.9) 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.

The Influence of Calcination Temperature on Quantitative Phase of Hematite from Iron Stone Tanah Laut

2015 ◽  
Vol 1112 ◽  
pp. 489-492
Author(s):  
Ali Mufid ◽  
M. Zainuri
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Thermo Gravimetric Analysis ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Co Precipitation

This research aims to form particles of hematite (α-Fe2O3) with a basis of mineral iron ore Fe3O4 from Tanah Laut. Magnetite Fe3O4 was synthesized using co-precipitation method. Further characterization using X-ray fluorescence (XRF) to obtain the percentage of the elements, obtained an iron content of 98.51%. Then characterized using thermo-gravimetric analysis and differential scanning calorimetry (TGA-DSC) to determine the calcination temperature, that at a temperature of 445 °C mass decreased by 0.369% due to increase in temperature. Further Characterization of X-ray diffraction (XRD) to determine the phases formed at the calcination temperature variation of 400 °C, 445 °C, 500 °C and 600 °C with a holding time of 5 hours to form a single phase α-Fe2O3 hematite. Testing with a particle size analyzer (PSA) to determine the particle size distribution, where test results indicate that the α-Fe2O3 phase of each having a particle size of 269.7 nm, 332.2 nm, 357.9 nm, 412.2 nm. The best quantity is shown at a temperature of 500 °C to form the hematite phase. This result is used as the calcination procedure to obtain a source of Fe ions in the manufacture of Lithium Ferro Phosphate.

Electrochemical Properties of Nanocrystalline Y2-xPrxRu2O7 Pyrochlore for Electrodic Application in IT-SOFCS

2006 ◽  
Vol 972 ◽  
Author(s):  
Chiara Abate ◽  
Keith Duncan ◽  
Enrico Traversa ◽  
Eric Wachsman
Keyword(s):  
Cathode Material ◽  
Phase Boundary ◽  
Electrochemical Impedance ◽  
Charge Transfer Resistance ◽  
Nanocrystalline Powders ◽  
Precipitation Method ◽  
Electrode Polarization ◽  
Transfer Resistance ◽  
Triple Phase Boundary ◽  
Co Precipitation

AbstractNanocrystalline powders of Y2-xPrxRu2O7 were prepared by a co-precipitation method, and were tested as electrode on ESB and GDC electrolytes by electrochemical impedance spectroscopy in the 300-750°C temperatures range. The electrode polarization was studied as a function of the amount of praseodymium in the cathode material. Both systems, Y2-xPrxRu2O7/ESB and Y2-xPrxRu2O7/GDC, showed a similar variation of the electrode area specific resistance (ASR). Y1.5Pr0.5Ru2O7 cathode material presented the best performance, with ASR value of 0.19 Ωcm2 on ESB and 4.23 Ωcm2 on GDC at 700°C. Furthermore, the change in ASR with the oxygen partial pressure suggested that the rate limiting step is the surface diffusion of the adsorbed oxygen at the electrode surface to the triple-phase boundary. Thus, the low value of resistivity of the Y1.5Pr0.5Ru2O7 in contact with ESB results from a much lower charge transfer resistance compared to the Y2-xPrxRu2O7/GDC system, and a partial solid diffusion at the interface electrode/electrolyte that increases the effective triple phase boundary length. This suggests that Y2-xPrxRu2O7 is a promising material for cathode application in ESB-based electrolyte for intermediate temperature solid oxide fuel cells (IT-SOFCs).

scholarly journals Inclusion Complex of Plai Oil and β-Cyclodextrin

2016 ◽  
Vol 855 ◽  
pp. 47-53
Author(s):  
Ampa Jimtaisong ◽  
Nisakorn Saewan
Keyword(s):  
Inclusion Complex ◽  
Inclusion Complexes ◽  
Physicochemical Characteristic ◽  
Precipitation Method ◽  
Ir Absorption ◽  
Scanning Calorimetry ◽  
Absorption Bands ◽  
Complex Preparation ◽  
Ft Ir ◽  
Co Precipitation

Inclusion complex of β-cyclodextrin (β-CD) and Plai (Zingiber cassumunar) oil was prepared using a simple co-precipitation method at β-CD to Plai oil in different ratios. The inclusion complexes were characterized using Fourier transform-infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). The FT-IR absorption bands of inclusion complex at 3600-3200 cm-1 were broader and shifted toward lower frequencies compared with that of pure β-CD (3359 cm-1). DSC of the inclusion complexes showed two endothermic peaks shifted to lower temperatures (90-100°C and 295-300°C) compared to that of β-CD. The different physicochemical characteristic could be an indication of an embedded guest molecule in the β-CD cavities in the inclusion complex preparation.

Graphene modified Li-rich cathode material Li[Li0.26Ni0.07Co0.07Mn0.56]O2 for lithium ion battery

2014 ◽  
Vol 07 (06) ◽  
pp. 1440013 ◽  
Author(s):  
Xiangjun Li ◽  
Hongxing Xin ◽  
Xiaoying Qin ◽  
Xueqin Yuan ◽  
Di Li ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Rate Capability ◽  
Lithium Ion ◽  
Cycling Performance ◽  
Precipitation Method ◽  
Electrochemical Performances ◽  
Charge Transfer Reaction ◽  
Ion Diffusion ◽  
Co Precipitation ◽  
Kinetics Of

Lithium and Mn rich solid solution materials Li [ Li 0.26 Ni 0.07 Co 0.07 Mn 0.56] O 2 were synthesized by a carbonate co-precipitation method and modified with a layer of graphene. The graphene-modified cathodes exhibit improved rate capability and cycling performance as compared to the bare cathodes. Electrochemical impedance spectroscopy (EIS) analyses reveal that the improved electrochemical performances are due to acceleration kinetics of lithium-ion diffusion and the charge transfer reaction of the graphene-modified cathodes.

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