固体氧化物燃料电池力学性能变化规律和断裂模式研究

Mechanical Properties and Fracture Mode of Anode Supported Solid Oxide Fuel Cell

采用同轴环施力法研究了单电池还原前后抗弯强度的Weibull模量与其厚度之间的关联性。结果表明:对应1.1、0.9 mm与0.7 mm 3个厚度,Ni O-YSZ(氧化钇稳定的氧化锆)阳极支撑单电池的Weibull模量分别为4.56、4.78与6.16,随着样品厚度降低,Weibull模量逐渐增加,这与阳极内部缺陷数量减少相对应;还原之后Ni-YSZ阳极支撑单电池的Weibull模量分别提高至8.66、12.49与9.37,塑性Ni相的形成是抑制裂纹扩展的主要原因,其中厚度为0.9mm的单电池呈现最佳的综合性能,对应特征强度为122.9 MPa。样品裂纹源主要源自于阳极支撑体的内部缺陷与Ni颗粒团聚,依此可以通过不同裂纹源的类型与3种断裂模式解释不同厚度单电池力学性能的变化规律。

The relationship between the Weibull modulus of bending strength and its thickness of single cell before and after reduction was investigated by a coaxial ring force method.The Weibull modulus of NiO-YSZ anode supported cell is 4.56,4.78 and 6.16 for the thickness of 1.1 mm,0.9 mm and 0.7 mm,respectively.The Weibull modulus increases gradually with the decrease of sample thickness due to the reduced internal defect number of anode.The Weibull modulus of Ni-YSZ anode supported cell increases to 8.66,12.49 and 9.37,respectively,since a plastic Ni phase inhibits the crack propagation.The single cell with a thickness of 0.9 mm shows a greater performance with the corresponding bending strength of 122.9 MPa.The crack sources of the sample mainly come from the internal defects of the anode and the agglomeration of Ni particles.Based on the experimental results,the influence of single cell thickness on its mechanical properties can be demonstrated at different crack source types and fracture modes.