The La0.6Ba0.4Co0.2Fe0.8O3 (LBCF) nano ceramic powders were prepared by Sol-Gel process using nitrate based chemicals for SOFC applications since these powders are considered to be more promising cathode materials for...The La0.6Ba0.4Co0.2Fe0.8O3 (LBCF) nano ceramic powders were prepared by Sol-Gel process using nitrate based chemicals for SOFC applications since these powders are considered to be more promising cathode materials for SOFC. Citric acid was used as a chelant agent and ethylene glycol as a dispersant. The powders were calcined at 650oC/6 h, 900oC/3 h in air using Thermolyne 47,900 furnace. These powders were charac terized by SEM/EDS, XRD and Porosimetry techniques. The SEM images indicate that the particle sizes of the LBCF powders are in the range of 50 - 200 nm. The LBCF perovskite phases are seen from the XRD patterns. From XRD Line broadening technique, the average particle size for the powders (as prepared and calcined at 650oC/6 h and 900oC/3 h) were found to be around 12.97 nm, 22.24 nm and 26 nm respectively. The surface area of the LBCF powders for the as prepared and calcined at 650oC were found to be 28.92 and 19.54 m2/g respectively.展开更多
采用EDTA-柠檬酸复合络合法合成了固体氧化物燃料电池(SOFC)纳米阴极粉体La0.6Sr0.4Co0.4Fe0.6O3(LSCF)。运用TG-DTA、FT-IR、XRD、SEM、TEM和电化学分析仪分别对产物形成过程、晶体结构、粉体形貌和电化学性能进行了分析与表征。实验...采用EDTA-柠檬酸复合络合法合成了固体氧化物燃料电池(SOFC)纳米阴极粉体La0.6Sr0.4Co0.4Fe0.6O3(LSCF)。运用TG-DTA、FT-IR、XRD、SEM、TEM和电化学分析仪分别对产物形成过程、晶体结构、粉体形貌和电化学性能进行了分析与表征。实验结果表明:在溶胶-凝胶法制备过程中,采用EDTA和柠檬酸同时作为络合剂进行络合反应所制备的凝胶,能在较低的温度(600℃)下生成按化学计量配比的钙钛矿晶体La0.6Sr0.4Co0.4Fe0.6O3,800℃下煅烧的粉体粒子仅为20～30nm,粒子大小较一致,团聚体较少,呈球形。进一步测试其电化学性能,采用该粉体制备阴极的阳极支撑型SOFC纽扣电池(GDC+Ni GDC LSCF)具有较高的性能,以氢气为燃料,空气为氧化剂,在700℃、750℃工作温度下,最大功率密度分别为0.72 W cm-2,0.85 W cm-2,与相同条件下采用柠檬酸单一络合法制备的LSCF粉体相比,电性能有明显提高,其最大功率在700℃、750℃下分别只有0.22 W cm-2、0.46 W cm-2。展开更多
A series samples of La0.6M0.4FeO3-δ （M = Ca, Sr, process （GNP）. FTIR, TG-DSC, XRD and TEM techniques Ba） perovskite-type oxides were prepared by glycine nitrate were used to characterize the chemical constitution...A series samples of La0.6M0.4FeO3-δ （M = Ca, Sr, process （GNP）. FTIR, TG-DSC, XRD and TEM techniques Ba） perovskite-type oxides were prepared by glycine nitrate were used to characterize the chemical constitution, thermal stability and phase structure. The electrical conductivity of the samples was investigated by four-probe technique. With the increase of substituted-ionic radius, the temperature of phase formation increases, and the solid solubility decreases gradually, respectively. The La0.6Ca0.4FeO3-δ（LCF）powder is pure cubic perovskite-type crystalline after fired at 850℃ for 2 h. The XRD patterns of La0.6Sr0.4FeO3-δ（LSF） powder shows a small quantity of SrO peaks sintered at 1050℃ for 2 h. The electrical conductivity of LCF and LSF at 500 - 800℃ is over 100 S·cm^ - 1, and the value of LCF is 1170 S·cm^ - 1 at 800℃, which indicate that LCF and LSF may be used as a profitable cathode for IT-SOFCs. The characteristic of La0.6 Ba0.4FeO3-δ（LBF） is poor, and the electrical conductivity at intermediate temperatures is 1/20 less than that of LSF.展开更多
文摘The La0.6Ba0.4Co0.2Fe0.8O3 (LBCF) nano ceramic powders were prepared by Sol-Gel process using nitrate based chemicals for SOFC applications since these powders are considered to be more promising cathode materials for SOFC. Citric acid was used as a chelant agent and ethylene glycol as a dispersant. The powders were calcined at 650oC/6 h, 900oC/3 h in air using Thermolyne 47,900 furnace. These powders were charac terized by SEM/EDS, XRD and Porosimetry techniques. The SEM images indicate that the particle sizes of the LBCF powders are in the range of 50 - 200 nm. The LBCF perovskite phases are seen from the XRD patterns. From XRD Line broadening technique, the average particle size for the powders (as prepared and calcined at 650oC/6 h and 900oC/3 h) were found to be around 12.97 nm, 22.24 nm and 26 nm respectively. The surface area of the LBCF powders for the as prepared and calcined at 650oC were found to be 28.92 and 19.54 m2/g respectively.
文摘采用EDTA-柠檬酸复合络合法合成了固体氧化物燃料电池(SOFC)纳米阴极粉体La0.6Sr0.4Co0.4Fe0.6O3(LSCF)。运用TG-DTA、FT-IR、XRD、SEM、TEM和电化学分析仪分别对产物形成过程、晶体结构、粉体形貌和电化学性能进行了分析与表征。实验结果表明:在溶胶-凝胶法制备过程中,采用EDTA和柠檬酸同时作为络合剂进行络合反应所制备的凝胶,能在较低的温度(600℃)下生成按化学计量配比的钙钛矿晶体La0.6Sr0.4Co0.4Fe0.6O3,800℃下煅烧的粉体粒子仅为20～30nm,粒子大小较一致,团聚体较少,呈球形。进一步测试其电化学性能,采用该粉体制备阴极的阳极支撑型SOFC纽扣电池(GDC+Ni GDC LSCF)具有较高的性能,以氢气为燃料,空气为氧化剂,在700℃、750℃工作温度下,最大功率密度分别为0.72 W cm-2,0.85 W cm-2,与相同条件下采用柠檬酸单一络合法制备的LSCF粉体相比,电性能有明显提高,其最大功率在700℃、750℃下分别只有0.22 W cm-2、0.46 W cm-2。
基金Project Supported bythe Natural Science Foundation of Bureau Education Anhui Province (N2004kj326)
文摘A series samples of La0.6M0.4FeO3-δ （M = Ca, Sr, process （GNP）. FTIR, TG-DSC, XRD and TEM techniques Ba） perovskite-type oxides were prepared by glycine nitrate were used to characterize the chemical constitution, thermal stability and phase structure. The electrical conductivity of the samples was investigated by four-probe technique. With the increase of substituted-ionic radius, the temperature of phase formation increases, and the solid solubility decreases gradually, respectively. The La0.6Ca0.4FeO3-δ（LCF）powder is pure cubic perovskite-type crystalline after fired at 850℃ for 2 h. The XRD patterns of La0.6Sr0.4FeO3-δ（LSF） powder shows a small quantity of SrO peaks sintered at 1050℃ for 2 h. The electrical conductivity of LCF and LSF at 500 - 800℃ is over 100 S·cm^ - 1, and the value of LCF is 1170 S·cm^ - 1 at 800℃, which indicate that LCF and LSF may be used as a profitable cathode for IT-SOFCs. The characteristic of La0.6 Ba0.4FeO3-δ（LBF） is poor, and the electrical conductivity at intermediate temperatures is 1/20 less than that of LSF.
