硼酸盐系微晶封接玻璃与IT-SOFC阳极材料的适应性研究

Adaptivity of Borate Sealing Glass-Ceramic System to IT-SOFC Anode Materials

以B2O3-Ca O-Ba O-Al2O3-Si O2-La2O3封接玻璃配方为主要研究对象,研究硼酸盐封接封接玻璃对电池元件的润湿等行为。优化的A4号和AC1号封接玻璃的TEC分布都在允许范围之内;微晶封接玻璃AC1和A4与阳极材料Ni-8YSZ的热膨胀匹配性均好,AC1比A4封接材料更符合600℃以上运行的IT-SOFC对封接材料的要求。经100 h长期热处理后,引入二价金属氧化物Ca2+后的AC1封接玻璃的TEC为11.42×10-6 K-1,增大了1.5%左右,显示了AC1封接玻璃具有好的热稳定性。随热处理时间增长,封接玻璃A4的TEC变化较小,也显示出了较好的热稳定性。AC1封接玻璃坯体在阳极材料Ni-8YSZ和电解质材料8YSZ表面的接触角,在900℃时为封接玻璃半球温度,此时封接材料与阳极材料充分浸润,比较适合进行封接,将温度继续升高至1000℃,浸润性能基本稳定,但仍然有一定的角度,封接材料不会在阳极平面上流平,而这个角度避免了封接材料在待封接组元表面出现流散现象,也能使其与阳极材料及电解质材料有良好的粘附性,有利于SOFC的封接。

This study mainly observed the B2O3-CaO-BaO-AI203-SiO2-La2O3 sealing glass system. The wetting behavior of the borosilieate glass on cell components was discussed. The TEC distribution of advanced A4 sealing glass and AC 1 sealing glass was in an acceptable range. Both the AC1 and A4 sealing glass-ceramics had good thermal expansion compatibility with the anode material NI-8YSZ. The ACI sealant better met the requirements for sealants operating above 600℃ than the A4 sealant. After 100 h heat treatment, the TEC of the bivalence metallic oxide Ca2＋ introduced sealing glass was 11.42×10.6 K^-1, which was increased about 1.5%. The result showed the AC1 sealing glass had good thermal stability. As the time of heat treatment increased, the TEC of the A4 sealing glass changed little and showed good thermal stability. The sealing glass formed a contact tangle with the anode material Ni-8YSZ and the electrolyte material 8YSZ.The glass reached its melting point at 900℃ when the sealant fully infiltrated into the anode material, which was suitable for sealing it. When the temperature increased to 1000℃, the wettability was basically stable, but there was still a certain wetting angle so that the sealant couldn＇t fully infiltrate the surface of the anode. However, the angle prevented the sealant from dissipation on the surface of the component to be sealed, and it also resulted in good adhesion between the anode material and the electrolyte material which is helpful for the sealing of SOFC.