BaO-CaO-Al_2O_3-B_2O_3-SiO_2微晶玻璃对大面积平板式IT-SOFC的封接性能

Sealing Propeties of BaO-CaO-Al_2O_3-B_2O_3-SiO_2 Glass-Ceramics to Large Size Planar IT-SOFC

研究了BaO-CaO-Al2O3-B2O3-SiO2(BCAS)玻璃在大面积平板式固体氧化物燃料电池(IT-SOFC)测试应用及性能。采用热膨胀仪、X射线衍射仪、扫描电子显微镜对在不同时间热处理情况下玻璃性能及微观结构影响进行表征。结果表明:在750℃,热处理0、50、100h后,BCAS玻璃的热膨胀系数分别为11.4×10-6、11.3×10-6与11.2×10-6 K-1,与电解质YSZ、阳极Ni-YSZ、金属连接板Crofer22APU的热膨胀系数相匹配。玻璃在热处理后析出针状的BaSiO3,BaCaSiO4与BaAl2Si2O8晶体。采用水系流延成型制备玻璃封接环并应用于大面积单电池的性能测试。以纯H2为燃料,O2为氧化气体,单电池在连续测试280h、750℃至常温热循环10次之后的开路电压为1.19V,电池的最大功率密度为0.42W/cm2。测试后的微晶玻璃与YSZ、阳极结合紧密,界面无裂纹及孔洞,且具有较好的化学稳定性。

Abstract： The application and property of BaO-CaO-Al2O3-B2O3-SiO2 （BCAS） glass-ceramics as a sealant for the large size pla- nar anode supported solid oxide fuel cells （SOFCs） were investigated. The properties and microstructure of the sealant in heat treatment for different durations were analyzed by thermal dilatometry, X-ray diffraction and scanning electron microscopy, re- spectively. The results show that the coefficients of thermal expansion of BCAS glass-ceramics are 11.4× 10-6 , 11.3 × 10-6 and 11.2X 10-6 K-1 after heat treatment for 0, 50 and 100 h, respectively, as matched with YSZ, Ni-YSZ and interconnect. The needlelike barium silicate, barium calcium silicate and hexacelsian can be crystallized in the microstructure of glass after heat-treatment at 750 ℃ for 50, 100 and 150 h. The glass-ceramics green tape obtained via a aqueous tape casing method can be used to seal the large size single cell. The open circuit voltage of the cell is 1.19 V at 750 ~C after continual testing for 280 h and 10-time thermal cycling in the temperature range from 750℃ to room temperature. The maximum power density of the large size single cell is 0.42 W/cm2 when pure H2 is used as a fuel and 02 is sued as an oxidation gas. It is also revealed that there is a well-adhered bonding between glass-ceramics and component without any crack, pore and element diffusion in the in- terface.