基于纳米CT技术研究运行后Ni-YSZ阳极三维微结构变化

发布时间：2018-01-02 12:18

本文关键词：基于纳米CT技术研究运行后Ni-YSZ阳极三维微结构变化　出处：《核技术》2016年06期 　论文类型：期刊论文

【摘要】：固体氧化物燃料电池(Solid Oxide Fuel Cell,SOFC)阳极不仅提供了电化学反应的三相界面(Three-phase boundary,TPB)区域,而且在物质传输、扩散和燃料电池反应中不同物质之间的隔离起到积极作用。在运行期间,电极微结构发生变化。对SOFC阳极微结构演变的研究能够帮助我们理解长期运行的SOFC性能损失的原因。近年来不断发展的X射线纳米CT(Computed Tomography)技术使得可以无损地获得测试前后的阳极三维微结构。本文利用硬X射线纳米CT技术对Ni-YSZ复合阳极进行了三维重建,并采用自主开发的一些定量分析方法来获得阳极微结构的关键参数,如颗粒尺寸、每种相的体积分数和连通率等。发现在电池测试后,Ni颗粒尺寸增大,与之相对是由于Ni颗粒的聚集导致Ni相的连通性和三相界面长度明显下降。结果表明,在电池测试过程,Ni颗粒发生了团聚,电极微结构发生了改变,进而导致SOFC性能损失。阳极结构的数据表明,X射线纳米CT技术能够作为一个强力工具研究能源材料的微结构,为阳极结构优化提供重要参考数据。
[Abstract]:Solid Oxide Fuel Cell. SOFC) anodes not only provide the three-phase boundary TPBs for electrochemical reactions, but also transport matter in the three-phase interface. Separation between different substances in diffusion and fuel cell reactions plays a positive role. During operation. The study of the evolution of SOFC anode microstructure can help us to understand the reason for the loss of SOFC performance. The recent development of X-ray nanocrystalline CTs (NCTs). Computed Tomography). The 3D microstructures of the anode before and after the test can be obtained without damage by using the hard X-ray nano-CT technique. In this paper, the three-dimensional reconstruction of the Ni-YSZ composite anode is carried out. Some quantitative analysis methods developed by ourselves were used to obtain the key parameters of anode microstructure, such as particle size, volume fraction and connectivity of each phase, etc. It was found that the size of Ni particles increased after battery testing. On the other hand, due to the aggregation of Ni particles, the connectivity of Ni phase and the length of three-phase interface decreased obviously. The results showed that the Ni particles were agglomerated and the electrode microstructure changed during the battery test. The data of anode structure show that X-ray nanocrystalline CT can be used as a powerful tool to study the microstructure of energy materials and provide important reference data for the optimization of anode structure.
【作者单位】：中国科学技术大学国家同步辐射实验室;
【基金】：国家自然科学基金(No.11275204,No.11475175,No.11405175,No.11205189) 国家重点基础研究发展计划(973计划)(No.2012CB825804)资助~~
【分类号】：TM911.4
【正文快照】： 固体氧化物燃料电池(Solid Oxide Fuel Cell,SOFC)是一种将燃料的化学能直接转化为电能的能源装置,它具有能量转化率高、稳定性好、燃料气体种类广泛和环境友好等优点[1]。SOFC阳极一般采用由金属Ni和氧离子导体材料氧化钇稳定氧化锆(Yttria-stabilized zirconia,YSZ)构成的复

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