冰模板法构建中低温SOFCs一体化梯度阳极的微观结构调控及性能研究

The anode supported SOFCs have attracted lots of attention due to their characteristics of low resistance and high power density. The porous structures in anode could affect the path of gas diffusion through the thick supporting layer and also the length of trip phase boundaries in the functional layer, resulting in the dramatic changes of the cell performance. Therefore, the optimization of anode microstructures is of importance. The aims of this project are to utilize the characteristics of graded structures (orderly exhibiting dense, cellular, lamellar layers) obtained by ice templating technique to realize the fabrication of the integral graded anode; to improve the pore architectures of the anode with graded distributional characteristic and the orientation of pores by adjusting the solids loading of the slurry, the cooling rate and electric field strength; to clarify the relationship between characteristics of graded pore structures and the transport kinetics as well as the electrocatalytic activities in the anode; to study the mechanical properties of the graded anode under thermal cycles; to clarify the evolution mechanism of the graded anode structure. This project is designed to provide helpful exploration for the low-cost fabrication of anode supported SOFCs with very good performance operated at low-temperature.

阳极支撑型SOFCs因具有低阻抗、高功率密度等优点而成为研究热点。阳极的多孔结构会直接影响气体扩散路径以及三相反应界面长度，进而引起电池性能的显著变化，因此优化阳极微结构尤为重要。本项目利用冰模板技术获得的材料依次呈现密实、海绵状、柱状多孔梯度结构的特点，实现功能层与支撑层一体化阳极的构建；通过浆料物性、冷却速率、外加电场调控梯度结构比例、孔取向来改善阳极孔结构；阐明梯度孔结构特征与阳极反应气输运及反应活性动力学的关系；研究梯度阳极在热循环条件下的力学性能，阐明阳极梯度结构演化机制。本项目希望为实现高性能中低温阳极支撑SOFCs的低成本构建，提供有益的探索。

阳极支撑型SOFCs具有低阻抗、高功率密度等优点，其多孔结构会直接影响气体扩散路径以及三相反应界面长度，进而引起电池性能的显著变化，优化阳极微结构十分关键。本项目利用冰模板技术获得的材料依次呈现密实、海绵状、柱状多孔梯度结构的特点，可实现功能层与支撑层一体化阳极的构建；通过调节浆料pH值、固相含量、凝固速率成功获得了YSZ多孔结构，孔径尺寸、陶瓷小臂介于几至几百微米之间，此梯度阳极YSZ多孔材料表现出较为优异的电化学性能；采用溅射法沉积了一体化梯度阳极支撑YSZ电解质薄膜，通过调整工艺参数调控阳极/电解质界面接触状态，并揭示应力松弛机制；发展了IrO2+YSZ复合阴极材料，可有效降低固体氧化物燃料电池工作温度和过电位。