新型陶瓷连接材料(Pr0.5Nd0.5)0.7Ca0.3CrO3–δ–Sm0.1Gd0.1Ce0.8O1.9的制备与性能

采用络合燃烧法制备(Pr0.5Nd0.5)0.7Ca0.3CrO3–δ(PNCC)–Sm0.1Gd0.1Ce0.8O2–δ(SGDC)复合陶瓷连接材料。利用X射线衍射仪和扫描电子显微镜对烧结体的物相和微观结构进行了表征,采用四端探针法测量电导率。结果表明:PNCC和SGDC在高温烧结时具有稳定的物相和良好的化学相容性,SGDC掺杂量为5%(质量分数)的样品,在1400℃烧结5h,相对密度高达97.1%;700℃时,烧结陶瓷体在空气和氢气气氛中的电导率分别为47S/cm和4S/cm;室温至1000℃范围内,样品的热膨胀系数为10.4×10–6K–1,与中温电解质的热膨胀系数接近,说明SGDC掺杂的PNCC体系有望成为良好的中温固体氧化物燃料电池复合连接材料。

Preparation and Performance of Novel Ceramic Interconnect Materials (Pr0.5Nd0.5)0.7Ca0.3CrO3-δ-Sm0.1Gd0.1Ce0.8O1.9

A composite of (Pr0.5Nd0.5)0.7Ca0.3CrO3–δ (PNCC)–Sm0.1Gd0.1Ce0.8O2–δ (SGDC) interconnect materials was synthesized by a sol–gel auto-ignition process. The phase and microstructure of the sintering sample were analyzed by X-ray diffraction and scanning electron microscope, respectively. The electrical conductivity of the samples was measured by four-probe technique. The results indi- cated that PNCC was chemically stable against reaction with SGDC at high temperatures. For 5% (in mass) SGDC, the relative den- sity of the sample was 97.1% after sintering at 1 400 ℃ for 5 h, and the electrical conductivity of the sample reached 47 S/cm in air and 4 S/cm in H 2 at 700 ℃. The average thermal expansion coefficient of the samplewas 10.4 × 10 –6 K –1 at room temperature to 1 000 ℃, which is close to that of electrolyte. Results indicate that the PNCC/SGDC composite is a very promising interconnect material for intermediate solid oxide fuel cells.