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
Sm0.2Ce0.8O1.9 （SDC） electrolyte was prepared by a modified solid state method at relatively low sintering temperatures without any sintering promoters. The phase composition and microstructure of the electrolytes w...Sm0.2Ce0.8O1.9 （SDC） electrolyte was prepared by a modified solid state method at relatively low sintering temperatures without any sintering promoters. The phase composition and microstructure of the electrolytes were investigated by X-ray diffraction （XRD） and field emission scanning electron microscopy （FESEM） technologies. A relative density of SDC electrolyte sintered at 1300 ℃ reached 97.3%and the mean SDC grain size was about 770 nm. Their ionic conductivity and thermal expansion coefficient were also measured by electrochemical workstation and dilatometer. The electrolyte attained a high conductivity of 5×10^-2 S/cm at 800 ℃ with an activation energy of 1.03 eV and a proper thermal expansion coefficient of 12.6×10^-6 K^-1.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
The nanocomposite electrolytes composed of Smo.2Ce0.801.9 （SDC） nanorods enclosed by { 110} and { 100} facets and a binary carbonate （（Lio.52Nao.48）2CO3, LNC） were prepared by a wet mixing method to investigate ...The nanocomposite electrolytes composed of Smo.2Ce0.801.9 （SDC） nanorods enclosed by { 110} and { 100} facets and a binary carbonate （（Lio.52Nao.48）2CO3, LNC） were prepared by a wet mixing method to investigate the conduction mechanism. The X-ray diffraction （XRD）, scanning electron microscopy （FESEM） and transmission electron microscopy （TEM） techniques were em- ployed to characterize the phase components and microstructures of SDC nanorods and SDC nanorods/LNC composite electrolytes. X-ray powder diffraction showed that a well-cubic fluorite structure was formed. The AC impedance spectroscopy and DC polariza- tion method were used to measure the electrical conductivities of nanocomposite electrolytes under different conditions. The overall ionic conductivities of nanocomposite electrolytes in the air and hydrogen atmospheres were measured up to 82 and 96 mS/cm at 650 ℃, respectively. Additionally, the protonic and oxide ionic conductivities of nanocomposite electrolytes were found to reach 20 and 18 mS/cm at 650 ℃, respectively. The conduction mechanism was discussed in detail by comparing the conductivities of nanocom- posite electrolytes. The protonic conductivity of SDC nanorods/LNC nanocomposite was higher than oxide ionic conductivity. The melt of LNC and the interface layer may make a dominant contribution to oxide ions and protonic conductivity in air and hydrogen atmosphere, respectively.展开更多
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supported by Program for Changjiang Scholars and Innovative Research Team in University(PCSIRT)(IRT1146)the Program of Research Innovation for University Graduate Students of Jiangsu Province(CXLX13_408)the Priority Academic Development Program of Jiangsu Higher Education Institutions,P.R.China
文摘Sm0.2Ce0.8O1.9 （SDC） electrolyte was prepared by a modified solid state method at relatively low sintering temperatures without any sintering promoters. The phase composition and microstructure of the electrolytes were investigated by X-ray diffraction （XRD） and field emission scanning electron microscopy （FESEM） technologies. A relative density of SDC electrolyte sintered at 1300 ℃ reached 97.3%and the mean SDC grain size was about 770 nm. Their ionic conductivity and thermal expansion coefficient were also measured by electrochemical workstation and dilatometer. The electrolyte attained a high conductivity of 5×10^-2 S/cm at 800 ℃ with an activation energy of 1.03 eV and a proper thermal expansion coefficient of 12.6×10^-6 K^-1.
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.
基金Project supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,P.R.Chinathe Program for Changjiang Scholars and Innovative Research Teams in Universities(PCSIRT,IRT_15R35)
文摘The nanocomposite electrolytes composed of Smo.2Ce0.801.9 （SDC） nanorods enclosed by { 110} and { 100} facets and a binary carbonate （（Lio.52Nao.48）2CO3, LNC） were prepared by a wet mixing method to investigate the conduction mechanism. The X-ray diffraction （XRD）, scanning electron microscopy （FESEM） and transmission electron microscopy （TEM） techniques were em- ployed to characterize the phase components and microstructures of SDC nanorods and SDC nanorods/LNC composite electrolytes. X-ray powder diffraction showed that a well-cubic fluorite structure was formed. The AC impedance spectroscopy and DC polariza- tion method were used to measure the electrical conductivities of nanocomposite electrolytes under different conditions. The overall ionic conductivities of nanocomposite electrolytes in the air and hydrogen atmospheres were measured up to 82 and 96 mS/cm at 650 ℃, respectively. Additionally, the protonic and oxide ionic conductivities of nanocomposite electrolytes were found to reach 20 and 18 mS/cm at 650 ℃, respectively. The conduction mechanism was discussed in detail by comparing the conductivities of nanocom- posite electrolytes. The protonic conductivity of SDC nanorods/LNC nanocomposite was higher than oxide ionic conductivity. The melt of LNC and the interface layer may make a dominant contribution to oxide ions and protonic conductivity in air and hydrogen atmosphere, respectively.
