悬浮液等离子喷涂中低温SOFC纳米复合阴极结构调控及服役性能研究

The performance of intermediate-temperature solid oxide fuel cell (SOFC) can be significantly improved by using the high-performance nano-composite cathodes. Until now, the most popular method for the preparation of composite cathode is porous backbone sintering and post infiltration. However, this process is complex and time-consuming, which is difficult for the large-scale fabrication. Therefore, there are still two main critical challenges for the development of nano-composite cathodes. One is how to achieve large-scale fabrication of high-performance nano-composite cathodes at low temperature; another is the microstructure and performance evolution during the cell operation for the nano-composite cathodes. In this project, we systematically investigated the feasibility of fabricating nano-composite cathodes by suspension plasma spraying since it can prepare fine and nanostructured coatings. The deposition behavior, mechanism, critical conditions and influences for nanostructure of suspension plasma sprayed nano-composite cathodes will be clarified. Besides, the microstructure evolution and its effects on the performance during the cell operation process will be explored. The research results will provide new idea and method for the design and fabrication of high-performance nano-composite cathodes. Finally, the nano-composite cathodes can be fabricated not only for the planer type SOFC, but also for the tubular SOFC and the cells which have a complex geometry. As a result, this project will provide important theory and technology guidance for the performance improvement of intermediate-temperature solid oxide fuel cell. Moreover, it will also accelerate the commercialization of SOFC technologies.

高性能纳米复合阴极对提升中低温固体氧化物燃料电池（SOFC）输出性能具有重要意义。当前，纳米复合阴极制备主要采用多孔骨架烧结加溶液浸渗的方法。然而该方法复杂耗时，难以实现大面积快速制备。因此，纳米复合阴极面临的关键问题在于如何在低温条件下大面积快速成型以及服役过程中结构与性能的演变。针对上述问题，本项目提出采用悬浮液等离子喷涂技术制备面向中低温SOFC的纳米复合阴极。明确悬浮液等离子喷涂纳米复合阴极的沉积行为与沉积机制，揭示纳米结构控制的关键条件与影响因素，探讨纳米复合阴极在服役过程中的结构演变规律及其对性能的影响，为高性能中低温SOFC纳米复合阴极的结构设计及制备提供新思路与新方法。该项目的完成，不仅可以实现各类平板状电池纳米复合阴极的低温、低成本制备，而且还可以面向大型的、具有复杂外形电池的纳米复合阴极的快速成型，对提升中低温SOFC输出性能及推进其商业化应用具有重要意义。

高性能纳米复合阴极对提升中低温固体氧化物燃料电池（SOFC）输出性能具有重要意义。.当前，纳米复合阴极制备主要采用多孔骨架烧结加溶液浸渗的方法。然而该方法复杂耗时，难以实现大面积快速制备。因此，纳米复合阴极面临的关键问题在于如何在低温条件下大面积快速成型以及服役过程中结构与性能的演变。针对上述问题，本项目采用液料等离子喷涂技术制备面向中低温SOFC的纳米阴极。明确了液料等离子喷涂纳米阴极的沉积行为与沉积机制，揭示了纳米结构控制的关键条件与影响因素，表征了纳米结构阴极在服役过程中的结构演变规律及其对性能的影响，为高性能中低温SOFC纳米复合阴极的结构设计及制备提供新思路与新方法。研究结果表明，纳米阴极结构可以通过调控液料或悬浮液浓度控制沉积体单元尺度获得。通过减少阴极颗粒尺度，阴极电化学性能显著提升。以LSCF体系为例，当阴极颗粒尺度低于100 nm时，600 oC阴极极化低至0.1  cm2。且以该阴极制备的全热喷涂金属支撑电池在中低温条件下具有优异的输出性能。在低于650 oC时具有优异的稳定性。 该项目的完成，不仅可以实现各类平板状电池纳米阴极的低温、低成本制备，而且还可以面向大型的、具有复杂外形电池的纳米复合阴极的快速成型，对提升中低温SOFC输出性能及推进其商业化应用具有重要意义。