通过甘氨酸硝酸盐法(GNP)合成了钙钛矿型Ba0.5Sr0.5Co0.8Fe0.2O3-δ(BSCF)复合氧化物粉体。经压制、烧结后,得到了BSCF烧结体试样,还通过硝酸溶液浸蚀处理对烧结体试样进行了表面浸蚀处理。采用X射线衍射仪(XRD)对煅烧后的粉体进...通过甘氨酸硝酸盐法(GNP)合成了钙钛矿型Ba0.5Sr0.5Co0.8Fe0.2O3-δ(BSCF)复合氧化物粉体。经压制、烧结后,得到了BSCF烧结体试样,还通过硝酸溶液浸蚀处理对烧结体试样进行了表面浸蚀处理。采用X射线衍射仪(XRD)对煅烧后的粉体进行了相成分分析;采用扫描电子显微镜(SEM)及能谱仪(EDS)对烧结体和表面浸蚀后烧结体样品的微观组织和成分进行了表征;对烧结体的致密度、电导率进行了测试分析,并在自制的氧渗透装置上测定了BSCF钙钛矿膜的透氧量,分析了温度和不同氧分压差等对膜透氧性能的影响。实验结果表明,甘氨酸-硝酸盐法所制备的前驱体粉末在900℃煅烧3 h后可获得具有单一钙钛矿结构的BSCF粉体,1100℃煅烧的BSCF烧结体的电导率在600℃时最大达到38.15 S·cm-1。其透氧量随着温度和氧分压差的升高而增大,且硝酸表面浸蚀处理后,BSCF膜片的透氧性能有明显提高,透氧速率提高1.6~4.5倍。850℃,20%O2-80%N2混合气体/He条件下,浸蚀后的透氧膜片的透氧量达到2.36 m L/cm2·min,而未浸蚀透氧膜片的透氧量仅为1.36 m L/cm2·min。展开更多
采用柠檬酸-硝酸盐自蔓延燃烧法分别合成了Pr_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)(PSCF)和Gd_(0.2)Ce_(0.8)O_(2-δ)(GDC)粉体,高温固相法合成La_(0.9)Sr_(0.1)Ga_(0.8)Mg_(0.2)O_(3-δ)(LSGM)电解质粉体。以LSGM为电解质,PSCF同时...采用柠檬酸-硝酸盐自蔓延燃烧法分别合成了Pr_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)(PSCF)和Gd_(0.2)Ce_(0.8)O_(2-δ)(GDC)粉体,高温固相法合成La_(0.9)Sr_(0.1)Ga_(0.8)Mg_(0.2)O_(3-δ)(LSGM)电解质粉体。以LSGM为电解质,PSCF同时作为阴极和阳极,GDC作为功能层材料,构建了对称固体氧化物燃料电池PSCF│GDC│LSGM│GDC│PSCF。利用X射线衍射法研究材料的成相以及相互间的化学稳定性,交流阻抗法记录界面极化行为,用扫描电子显微镜观察电池的断面微结构,用自组装的测试系统评价电池输出性能。结果表明,合成的PSCF粉体呈立方钙钛矿结构,具有良好的氧化–还原可逆性。使用GDC功能层明显改善了氢气环境下PSCF与LSGM材料间的化学相容性以及电池的输出性能,800℃时,电极│电解质界面极化电阻从6.892?·cm^2下降到0.314?·cm^2;以加湿H_2(含体积分数3%的水蒸气)为燃料气,空气为氧化气时,单电池输出功率密度由269 m W/cm2增大至463 m W/cm^2。研究结果显示,PSCF是对称固体氧化物燃料电池良好的候选电极材料,GDC功能层对改善电池长期稳定性能具有潜在的应用价值。展开更多
The phase composition, microstructure, thermal expansion coefficients, oxygen permeation properties and chemical stability of SrCo0.8Fe0.2O3-δ (SCFM) were investigated and compared with those of SrCo0.8Fe0.2O3-δ(...The phase composition, microstructure, thermal expansion coefficients, oxygen permeation properties and chemical stability of SrCo0.8Fe0.2O3-δ (SCFM) were investigated and compared with those of SrCo0.8Fe0.2O3-δ(SCF). Single phase SCFM was successfully prepared by a combined EDTA-citric method. SCFM shows a lower thermal expansion coefficient (24× 10^-6-29× 10^-6/K) than SCF between 500 and 1050 ℃, indicating a more stable structure. SCFM shows a high oxygen permeation flux, although the oxygen flux of SCFM decreases slightly because of Mo dopant. Furthermore, it was demonstrated that the doping of Mo in SCF can prevent the order-disorder transition and improves the chemical stability to CO2.展开更多
文摘通过甘氨酸硝酸盐法(GNP)合成了钙钛矿型Ba0.5Sr0.5Co0.8Fe0.2O3-δ(BSCF)复合氧化物粉体。经压制、烧结后,得到了BSCF烧结体试样,还通过硝酸溶液浸蚀处理对烧结体试样进行了表面浸蚀处理。采用X射线衍射仪(XRD)对煅烧后的粉体进行了相成分分析;采用扫描电子显微镜(SEM)及能谱仪(EDS)对烧结体和表面浸蚀后烧结体样品的微观组织和成分进行了表征;对烧结体的致密度、电导率进行了测试分析,并在自制的氧渗透装置上测定了BSCF钙钛矿膜的透氧量,分析了温度和不同氧分压差等对膜透氧性能的影响。实验结果表明,甘氨酸-硝酸盐法所制备的前驱体粉末在900℃煅烧3 h后可获得具有单一钙钛矿结构的BSCF粉体,1100℃煅烧的BSCF烧结体的电导率在600℃时最大达到38.15 S·cm-1。其透氧量随着温度和氧分压差的升高而增大,且硝酸表面浸蚀处理后,BSCF膜片的透氧性能有明显提高,透氧速率提高1.6~4.5倍。850℃,20%O2-80%N2混合气体/He条件下,浸蚀后的透氧膜片的透氧量达到2.36 m L/cm2·min,而未浸蚀透氧膜片的透氧量仅为1.36 m L/cm2·min。
文摘采用柠檬酸-硝酸盐自蔓延燃烧法分别合成了Pr_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)(PSCF)和Gd_(0.2)Ce_(0.8)O_(2-δ)(GDC)粉体,高温固相法合成La_(0.9)Sr_(0.1)Ga_(0.8)Mg_(0.2)O_(3-δ)(LSGM)电解质粉体。以LSGM为电解质,PSCF同时作为阴极和阳极,GDC作为功能层材料,构建了对称固体氧化物燃料电池PSCF│GDC│LSGM│GDC│PSCF。利用X射线衍射法研究材料的成相以及相互间的化学稳定性,交流阻抗法记录界面极化行为,用扫描电子显微镜观察电池的断面微结构,用自组装的测试系统评价电池输出性能。结果表明,合成的PSCF粉体呈立方钙钛矿结构,具有良好的氧化–还原可逆性。使用GDC功能层明显改善了氢气环境下PSCF与LSGM材料间的化学相容性以及电池的输出性能,800℃时,电极│电解质界面极化电阻从6.892?·cm^2下降到0.314?·cm^2;以加湿H_2(含体积分数3%的水蒸气)为燃料气,空气为氧化气时,单电池输出功率密度由269 m W/cm2增大至463 m W/cm^2。研究结果显示,PSCF是对称固体氧化物燃料电池良好的候选电极材料,GDC功能层对改善电池长期稳定性能具有潜在的应用价值。
文摘The phase composition, microstructure, thermal expansion coefficients, oxygen permeation properties and chemical stability of SrCo0.8Fe0.2O3-δ (SCFM) were investigated and compared with those of SrCo0.8Fe0.2O3-δ(SCF). Single phase SCFM was successfully prepared by a combined EDTA-citric method. SCFM shows a lower thermal expansion coefficient (24× 10^-6-29× 10^-6/K) than SCF between 500 and 1050 ℃, indicating a more stable structure. SCFM shows a high oxygen permeation flux, although the oxygen flux of SCFM decreases slightly because of Mo dopant. Furthermore, it was demonstrated that the doping of Mo in SCF can prevent the order-disorder transition and improves the chemical stability to CO2.