摘要
采用柠檬酸–硝酸盐自蔓延燃烧法分别合成了双钙钛矿结构的SmBaCo2O5+δ(SBCO)阴极粉体和萤石型Sm0.2Ce0.8O1.9(SDC)电解质粉体,按3:2的质量比混合上述粉体研磨后得到复合阴极。利用X射线衍射仪研究化学相容性,直流四端子法测量电导率,热膨胀仪测量热膨胀系数;构建阳极支撑型单电池(Ni-SDC|SDC|SBCO-SDC)并进行了性能测试,用扫描电子显微镜观察电池的断面微结构,交流阻抗谱记录界面极化。结果表明:SBCO与SDC在1 000℃无相互作用;450～800℃,复合阴极的电导率在369～234 S/cm之间;SDC的加入降低了复合阴极的热膨胀系数;单电池具有理想的微观结构,阳极|电解质|阴极各界面彼此接触良好,650℃时极化电阻仅为0.031.cm2;以H2为燃料气(含体积分数3%水蒸气),空气为氧化剂,650℃时电池的开路电压为0.77 V,输出功率最大值为640 mW/cm2。预示着SBCO-SDC是中温固体氧化物燃料电池有潜力的阴极材料。
The cathode powder of double perovskites-type SmBaCo 2 O 5＋δ（SBCO） and electrolyte powder of fluorite-structure Sm 0.2 Ce 0.8 O 1.9（SDC） were synthesized by a citric acid-nitrates self-propagating combustion method.The composite-cathode was obtained by mixing and grinding the SBCO and SDC powders at a mass ratio of 3：2.The chemical compatibility,electrical conductivity and thermal expansion coefficient（TEC） of the composite-cathode（SBCO-SDC） were characterized by X-ray diffraction,direct current four-terminal method and thermal dilatometry,respectively.An anode-supporting fuel cell of Ni-SDC｜SDC｜SBCO-SDC was fabricated and the performance of the cell was analyzed.The cross-section microstructure and polarization of the cell were investigated using a scanning electron microscope（SEM） and AC impedance spectroscopy.The results indicate that there are no interactions between SBCO and SDC at 1 000 ℃.The electrical conductivity of the SBCO-SDC composite-cathode reached to 369–234 S/cm at 450–800 ℃.The addition of SDC decreased the TEC of the composite-cathode.The single cell has an ideal microstructure and a good interface among anode,electrolyte and cathode.The polarization resistance of the electrodes was 0.031.cm 2 at 650 ℃.The cell with an open-circuit potential of 0.77 V and a maximum output power density of 640 mW/cm 2 was obtained when the humidified（about 3% H 2 O） hydrogen as a fuel and air as oxidant were used at 650 ℃.It was demonstrated that the SBCO-SDC composite-cathode could be used as a potential candidate cathode for intermediate temperature solid oxide fuel cell.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2012年第10期1524-1529,共6页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金(51102107)
安徽省教育厅自然科学基金(KJ2008A150)
淮南市科技计划(2010A03203)资助项目
关键词
复合阴极
中温固体氧化物燃料电池
电化学性能
极化
composite-cathode
intermediate temperature solid oxide fuel cell
electrochemical performance
polarization
