As an ionic conductive functional layer of intermediate temperature solid oxide fuel cells(ITSOFC), samarium-doped ceria(SDC)–Li Na SO4nano-composites were synthesized by a sol–gel method and their properties were i...As an ionic conductive functional layer of intermediate temperature solid oxide fuel cells(ITSOFC), samarium-doped ceria(SDC)–Li Na SO4nano-composites were synthesized by a sol–gel method and their properties were investigated. It was found that the content of Li Na SO4 strongly affected the crystal phase, defect concentration, and conductivity of the composites. When the content of Li Na SO4 was 20 wt%, the highest conductivity of the composite was found to be, respectively, 0.22, 0.26, and 0.35 S cm-1at temperatures of 550, 600, and 700 °C, which are much higher than those of SDC. The peak power density of the single cell using this composite as an interlayer was improved to, respectively, 0.23, 0.39, and 0.88 W cm-2at 500, 600, and 700 °C comparing with that of the SDC-based cell. Further, the SDC–Li Na SO4(20 wt%)-based cell also displayed better thermal stability according to the performance measurements at 560 °C for 50 h. These results reveal that SDC–Li Na SO4 composite may be a potential good candidate as interlayer for ITSOFC due to its high ionic conductivity and thermal stability.展开更多
The cathode material La1-xSrxCuO3-δ(x=0.15, 0.2, 0.3, 0.4) was synthesized by a sol-gel method. X-ray diffraction reveals that a single phase of perovskite is formed. The investigation of the electrical properties su...The cathode material La1-xSrxCuO3-δ(x=0.15, 0.2, 0.3, 0.4) was synthesized by a sol-gel method. X-ray diffraction reveals that a single phase of perovskite is formed. The investigation of the electrical properties suggests that La0.7Sr0.3CuO3-δ has the highest electrical conductivity. La0.7Sr0.3CuO3-δ powder was mixed with different amount SDC (Sm0.15Ce0.85O1.925) powder (5wt.%-30wt.%) as composite cathodes. Electrochemical properties of the composite cathodes were researched further. Investigation suggests that the addition of appropriate amount SDC to La0.7Sr0.3CuO3-δ can improve the electrochemical properties and obtain better cathodic performance. Using La0.7Sr0.3CuO3-δ-SDC composite materials as a cathode based on SDC electrolyte, higher current density and power density at intermediate temperatures can be obtained.展开更多
Composites consisting of strontium stabilized bismuth oxide （Bi1.14Sr0.43O2.14, SSB） and silver were investigated as cathodes for intermediate-temperature solid oxide fuel cells with doped ceria electrolyte. There w...Composites consisting of strontium stabilized bismuth oxide （Bi1.14Sr0.43O2.14, SSB） and silver were investigated as cathodes for intermediate-temperature solid oxide fuel cells with doped ceria electrolyte. There were no chemical reactions between the two components. The microstructure of the interfaces between composite cathodes and Ce0.8Sm0.2O1.9 （SDC） electrolytes was examined by scanning electron microscopy （SEM）. Impedance spectroscopy measurements show that the performance of cathode fired at 700 ℃ is the best. When the content of Ag2O is 70 wt%, polarization resistance values for the SSB-Ag cathodes are as low as 0.2 Ωcm^2 at 700℃ and 0.29 Ωcm^2 at 650℃. These results are much smaller than some of other reported composite cathodes on doped ceria electrolyte and indicate that SSB-Ag composite is a potential cathode material for intermediate temperature SOFCs.展开更多
NiO/SDC composites and Ni/SDC cermets for solid oxide fuel cell （SOFC） anode applications were prepared from nickel oxide （NiO） and samada doped ceria （SDC） powders by the powder metallurgy process. The physical...NiO/SDC composites and Ni/SDC cermets for solid oxide fuel cell （SOFC） anode applications were prepared from nickel oxide （NiO） and samada doped ceria （SDC） powders by the powder metallurgy process. The physical and mechanical properties, as well as the microstructure of the NiO/SDC composites and the Ni/SDC cermets were investigated. It is shown that the sintedng temperature of the NiO/SDC composites and NiO content plays an important role in determining the microstructure and properties of the NiO/SDC composites, which, in turn, influences the microstructure, electrical conductivity, and mechanical properties of the Ni/SDC cermets. The present study demonstrated that composition and tprocess parameters must be appropriately selected to optimize the microstructure and the properties of NiO/SDC materials for solid oxide fuel cell applications.展开更多
Ce0.85Sm0.15O1.925 （SDC） and La0.9Sr0.1Ga0.5Mg0.2O2.85 （LSGM） were synthesized using Glycine-Nitrate Process （GNP）, and the composite electrolytes were prepared by mixing SDC and LSGM. An X-ray diffraction patte...Ce0.85Sm0.15O1.925 （SDC） and La0.9Sr0.1Ga0.5Mg0.2O2.85 （LSGM） were synthesized using Glycine-Nitrate Process （GNP）, and the composite electrolytes were prepared by mixing SDC and LSGM. An X-ray diffraction pattern indicated that the mixture of SDC and LSGM consisted of their original phases after heating at 1450 ℃ for 10 h. The electronic conductivity of SDC-LSGM composite electrolytes were measured by direct current polarization method using Hebb-Wagner ion blocking cell at 700-800 ℃ in the oxygen partial pressure range of 104-10-20 MPa and compared with the results of SDC. Typical polarization curves, which were theoretically predicted, were observed on all the samples. The slopes of lgσe-lgPo2 plot for all the composite electrolytes agreed with the theoretically predicted value of-1/4 at some intermediate oxygen partial pressures and -1/6 at low oxygen partial pressure. The electronic conductivity of SDC-LSGM composite electrolytes decreased with the increase in LSGM content, whereas the ionic transport number ti of all the samples increased with the increase in LSGM content.展开更多
The properties of LSO-SDC composite electrolytes prepared by the mixed powder with different LSO/SDC mass ratios were studied. The apatite-type lanthanum silicates La10Si6O27（LSO） and Sm0.2Ce0.8O1.9（SDC） were synt...The properties of LSO-SDC composite electrolytes prepared by the mixed powder with different LSO/SDC mass ratios were studied. The apatite-type lanthanum silicates La10Si6O27（LSO） and Sm0.2Ce0.8O1.9（SDC） were synthesized via sol-gel process and glycine-nitrate process（GNP）, respectively. The phase structure, microstructure, relative density, thermal expansion properties and oxygen ion conductivity of the samples were investigated by means of techniques such as X-ray diffraction（XRD）, scanning electron microscopy（SEM）, Archimedes method, dilatometer, and AC impedance spectroscopy. The results showed that SDC addition to the samples could enhance the density of the samples. However, the LSO-SDC composite electrolyte sintered at 1550 oC was over sintering when the SDC content was 50 wt.%. At the lower content of SDC（0–10 wt.%）, the decrease of conductivity was predominantly attributed to the reducing concentration of carriers. However, the conductivities of the composite electrolytes increased with the increasing SDC content（10 wt.%–40 wt.%） because of the enhanced percolation of highly conductive SDC component in the microstructure of composite electrolytes. In addition,the dependence of conductivity on p（O2） showed that LSO-SDC composite electrolytes were stable in the examined range of p（O2）.展开更多
The Ba Ce0.8Y0.2O2.9-Ce0.85Sm0.15O1.925 composite electrolytes were prepared with Ba Ce0.8Y0.2O2.9(BCY) and Ce0.85Sm0.15O1.925(SDC). The SDC and BCY powders were mixed in the weight ratio of 95:5, 85:15, and 75:25, re...The Ba Ce0.8Y0.2O2.9-Ce0.85Sm0.15O1.925 composite electrolytes were prepared with Ba Ce0.8Y0.2O2.9(BCY) and Ce0.85Sm0.15O1.925(SDC). The SDC and BCY powders were mixed in the weight ratio of 95:5, 85:15, and 75:25, respectively(named as BS95, BS85, and BS75). Because of the composite effect between the SDC and BCY phases, the BS95 and BS85 exhibit improved conductivity compared with the pure SDC and BCY. The conductivity of BS95 is higher than that of BS85, indicating that the composite effect of BS95 is greater than that of BS85. Nevertheless, the composite effect in BS75 does not exist. Hence, we conclude that the composite effect in the BCY-SDC composites will decrease with the increase of the amount of BCY and even disappear when the amount of BCY exceeds a certain value. In our case, the optimum composition of the composite electrolyte is 95 wt% SDC and 5 wt% BCY. The BS95 has the highest conductivity(σ1t=0.07808 S cm-1, at 800 °C) and the fuel cell based on the BS95 shows the best performance(the maximum power density reaches as high as 526 mw cm-2 at 750 °C). The encouraging results suggest that the BCY-SDC composites are the very promising electrolyte materials for IT-SOFCs.展开更多
基金supported by the Natural Science Foundation of China(21173147 and 21376143)973 Program of China(2014CB239700)
文摘As an ionic conductive functional layer of intermediate temperature solid oxide fuel cells(ITSOFC), samarium-doped ceria(SDC)–Li Na SO4nano-composites were synthesized by a sol–gel method and their properties were investigated. It was found that the content of Li Na SO4 strongly affected the crystal phase, defect concentration, and conductivity of the composites. When the content of Li Na SO4 was 20 wt%, the highest conductivity of the composite was found to be, respectively, 0.22, 0.26, and 0.35 S cm-1at temperatures of 550, 600, and 700 °C, which are much higher than those of SDC. The peak power density of the single cell using this composite as an interlayer was improved to, respectively, 0.23, 0.39, and 0.88 W cm-2at 500, 600, and 700 °C comparing with that of the SDC-based cell. Further, the SDC–Li Na SO4(20 wt%)-based cell also displayed better thermal stability according to the performance measurements at 560 °C for 50 h. These results reveal that SDC–Li Na SO4 composite may be a potential good candidate as interlayer for ITSOFC due to its high ionic conductivity and thermal stability.
文摘The cathode material La1-xSrxCuO3-δ(x=0.15, 0.2, 0.3, 0.4) was synthesized by a sol-gel method. X-ray diffraction reveals that a single phase of perovskite is formed. The investigation of the electrical properties suggests that La0.7Sr0.3CuO3-δ has the highest electrical conductivity. La0.7Sr0.3CuO3-δ powder was mixed with different amount SDC (Sm0.15Ce0.85O1.925) powder (5wt.%-30wt.%) as composite cathodes. Electrochemical properties of the composite cathodes were researched further. Investigation suggests that the addition of appropriate amount SDC to La0.7Sr0.3CuO3-δ can improve the electrochemical properties and obtain better cathodic performance. Using La0.7Sr0.3CuO3-δ-SDC composite materials as a cathode based on SDC electrolyte, higher current density and power density at intermediate temperatures can be obtained.
基金Funded by the National Natural Science Foundation of China(No.20576063)the 973 Project of Ministry of Science and Technology in China(No.T2000026410)
文摘Composites consisting of strontium stabilized bismuth oxide （Bi1.14Sr0.43O2.14, SSB） and silver were investigated as cathodes for intermediate-temperature solid oxide fuel cells with doped ceria electrolyte. There were no chemical reactions between the two components. The microstructure of the interfaces between composite cathodes and Ce0.8Sm0.2O1.9 （SDC） electrolytes was examined by scanning electron microscopy （SEM）. Impedance spectroscopy measurements show that the performance of cathode fired at 700 ℃ is the best. When the content of Ag2O is 70 wt%, polarization resistance values for the SSB-Ag cathodes are as low as 0.2 Ωcm^2 at 700℃ and 0.29 Ωcm^2 at 650℃. These results are much smaller than some of other reported composite cathodes on doped ceria electrolyte and indicate that SSB-Ag composite is a potential cathode material for intermediate temperature SOFCs.
文摘用甘氨酸-硝酸盐法制备了具有高比表面积的纳米粒子NiO和Ce0.85Sm0.15O2-δ(SDC),用固相合成法制备了Ni-SDC复合阳极材料,通过测量过电位和电导率对其性能进行比较,研究微结构对复合阳极电化学性能的影响.结果表明,由于阳极组成和制备条件不同导致的微结构的变化,对阳极性能有很大影响.通过调整微结构,可以使阳极过电位和电导率明显改善.用甘氨酸-硝酸盐法制备SDC与NiO初始粉末,将2种初始粉末在600℃预烧,混合后得到的复合阳极具有优异的电化学性能.在600℃时,样品在氢气气氛下的电导率达到了3 534 S/cm,电流密度为0.5 A/cm2时样品过电位是0.18 V.
基金This work was financially supported by the National Key Fundamental Research and Development Program of China (No. G2000026409).
文摘NiO/SDC composites and Ni/SDC cermets for solid oxide fuel cell （SOFC） anode applications were prepared from nickel oxide （NiO） and samada doped ceria （SDC） powders by the powder metallurgy process. The physical and mechanical properties, as well as the microstructure of the NiO/SDC composites and the Ni/SDC cermets were investigated. It is shown that the sintedng temperature of the NiO/SDC composites and NiO content plays an important role in determining the microstructure and properties of the NiO/SDC composites, which, in turn, influences the microstructure, electrical conductivity, and mechanical properties of the Ni/SDC cermets. The present study demonstrated that composition and tprocess parameters must be appropriately selected to optimize the microstructure and the properties of NiO/SDC materials for solid oxide fuel cell applications.
基金the National Natural Science Foundation of China (10674034)
文摘Ce0.85Sm0.15O1.925 （SDC） and La0.9Sr0.1Ga0.5Mg0.2O2.85 （LSGM） were synthesized using Glycine-Nitrate Process （GNP）, and the composite electrolytes were prepared by mixing SDC and LSGM. An X-ray diffraction pattern indicated that the mixture of SDC and LSGM consisted of their original phases after heating at 1450 ℃ for 10 h. The electronic conductivity of SDC-LSGM composite electrolytes were measured by direct current polarization method using Hebb-Wagner ion blocking cell at 700-800 ℃ in the oxygen partial pressure range of 104-10-20 MPa and compared with the results of SDC. Typical polarization curves, which were theoretically predicted, were observed on all the samples. The slopes of lgσe-lgPo2 plot for all the composite electrolytes agreed with the theoretically predicted value of-1/4 at some intermediate oxygen partial pressures and -1/6 at low oxygen partial pressure. The electronic conductivity of SDC-LSGM composite electrolytes decreased with the increase in LSGM content, whereas the ionic transport number ti of all the samples increased with the increase in LSGM content.
基金Project supported by Natural Science Foundation for the Youth of China(51202211)Natural Science Foundation of Jiangsu Province(BK20140473)
文摘The properties of LSO-SDC composite electrolytes prepared by the mixed powder with different LSO/SDC mass ratios were studied. The apatite-type lanthanum silicates La10Si6O27（LSO） and Sm0.2Ce0.8O1.9（SDC） were synthesized via sol-gel process and glycine-nitrate process（GNP）, respectively. The phase structure, microstructure, relative density, thermal expansion properties and oxygen ion conductivity of the samples were investigated by means of techniques such as X-ray diffraction（XRD）, scanning electron microscopy（SEM）, Archimedes method, dilatometer, and AC impedance spectroscopy. The results showed that SDC addition to the samples could enhance the density of the samples. However, the LSO-SDC composite electrolyte sintered at 1550 oC was over sintering when the SDC content was 50 wt.%. At the lower content of SDC（0–10 wt.%）, the decrease of conductivity was predominantly attributed to the reducing concentration of carriers. However, the conductivities of the composite electrolytes increased with the increasing SDC content（10 wt.%–40 wt.%） because of the enhanced percolation of highly conductive SDC component in the microstructure of composite electrolytes. In addition,the dependence of conductivity on p（O2） showed that LSO-SDC composite electrolytes were stable in the examined range of p（O2）.
基金supported by the Natural Science Foundation of Liaoning Province(2013020010)
文摘The Ba Ce0.8Y0.2O2.9-Ce0.85Sm0.15O1.925 composite electrolytes were prepared with Ba Ce0.8Y0.2O2.9(BCY) and Ce0.85Sm0.15O1.925(SDC). The SDC and BCY powders were mixed in the weight ratio of 95:5, 85:15, and 75:25, respectively(named as BS95, BS85, and BS75). Because of the composite effect between the SDC and BCY phases, the BS95 and BS85 exhibit improved conductivity compared with the pure SDC and BCY. The conductivity of BS95 is higher than that of BS85, indicating that the composite effect of BS95 is greater than that of BS85. Nevertheless, the composite effect in BS75 does not exist. Hence, we conclude that the composite effect in the BCY-SDC composites will decrease with the increase of the amount of BCY and even disappear when the amount of BCY exceeds a certain value. In our case, the optimum composition of the composite electrolyte is 95 wt% SDC and 5 wt% BCY. The BS95 has the highest conductivity(σ1t=0.07808 S cm-1, at 800 °C) and the fuel cell based on the BS95 shows the best performance(the maximum power density reaches as high as 526 mw cm-2 at 750 °C). The encouraging results suggest that the BCY-SDC composites are the very promising electrolyte materials for IT-SOFCs.
