中温固体氧化物燃料电池新型层状钙钛矿阴极材料Y_(0.8)Ca_(0.2)BaCo_2O_(5+δ)（英文）

Novel Layered Perovskite Oxide Y_(0.8)Ca_(0.2)BaCo_2O_(5+δ) as Cathode for Intermediate Temperature Solid Oxide Fuel Cells

研究了中温固体氧化物燃料电池的新型层状钙钛矿Y0．8Ca0．2BaCo2O5＋δ（YCBC）极材料。采用柠檬酸—硝酸盐自蔓延燃烧法合成了YCBC以及YBaCo2O5＋δ（YBC）粉体。X射线衍射结果表明：YCBC粉体在950℃空气中煅烧3h能够很好地成相，而YBC粉体需要1100℃。电导率测试结果表明：在整个测试温度350-800℃范围内，YCBC的电导率（435～506s／cm）明显比YBC的电导率（205～323S／cm）。使用电化学阻抗谱技术测试了对称电池YCBC／SDC／YCBC和阳极支撑的单电池YCBC／SDC／Ni—SDC的电化学性能。以H2为燃料气（含体积分数3％水蒸气），空气为氧化剂，650℃时单电池YCBC／SDC/Ni—SDC的最大输出功率为351mW／cm^2。目前研究表明YCBC是具有潜力的中温固体氧化物燃料电池阴极材料。

A novel Ca-doped layered perovskite oxide Y0.8Ca0.2BaCo2O5＋δ （YCBC） was investigated as cathode material for intermediate-temperature solid oxide fuel cells （IT-SOFCs）. The YCBC and YBaCo2O5＋δ （YBC） powders were successfully synthesized by citric acid-nitrates self-propagating combustion method. X-ray diffraction confirmed that YCBC material calcined at 950 ~C for 3 h in air was well crystallized, but the well crystallized YBC occurred at 1 100 ~C. The electrical conductivity measurement showed that YCBC sample exhibited higher conductivity （of 435-505 S/cm） than that of YBC （of 205-323 S/cm） at the entire testing temperature range from 350-800 ~C. Symmetrical electrochemical cell with the configuration of YCBC/SDC/YCBC and an anode-supported sin- gle cell of YCBC/SDC/Ni-SDC were investigated using electrochemical impedance spectroscopy. The single cell of YCBC/SDC/Ni-SDC with humidified hydrogen （about 3% H20） as fuel and static air as oxidant exhibited excellent power density as high as 351 mW/cm2 at 650 ℃. Present results demonstrated that YCBC cathode material was a very promising cathode for intermediate temperature solid oxide fuel cells.