静态排水燃料电池中的气液传导过程及膜电极微观结构研究

To improve the utilization of reactive gases of fuel cell and lower the exhaust emissions to the least, UTC Fuel Cells, LLC invented a "semi transmissive" porous graphite bipolar plate, which could complete the function of gas separation and electricity conduction, and exhaust the residual water by penetrating through the micro pores. Compared with conventional water removal process purging by exhaust gases, this water removal process was named as static drain and the conventional one as dynamic drain. In this subject, the fuel cell with static drain will be focused and the gas-liquid conductive process inside the membrane electrode assembly (MEA) will be studied. Effect of water removing method on mass transport in the micro pores of MEA and cell performance will be investigated. To inspect the water moving process on boundary between MEA and bipolar plate under different water removing method, a transparent fuel cell may be designed, potential sensor and electrochemical impendance measurement will be adopted, and the water removal efficiency will be analyzed. Further, impact of MEA micro structure on cell performance with static drain is going to be researched and improved MEA suitable for static drain will be developed.

为了提高燃料电池中反应气体的利用率，将电池尾排降至最低，美国UTC公司发明了一种"半透过型"多孔石墨双极板，该双极板可以完成气体阻隔和电的传导等作用，同时，在电池运行时允许液态水直接从石墨微孔中透过而得到移除。与传统的液态水随气体尾排移除的方式相比，这种排水技术称为静态排水，而传统排水技术称为动态排水。 本课题将围绕着静态排水技术的燃料电池开展膜电极内部气液传输特性研究，考察排水方式的改变对电极毛细孔中的传质过程的影响，以及对电池输出性能的影响等；将设计可视燃料电池结构，结合电势探针测试方法，利用阻抗等分析手段研究静态排水燃料电池中膜电极与双极板界面处的液滴运动特性，对比分析不同排水方式下液态水的移除效率。将分析膜电极的微观结构对静态排水燃料电池输出性能的影响，进而优化电极结构，开发出适用于静态排水技术的膜电极。

为提高燃料电池中反应气体的利用率，将电池尾排降至最低，美国UTC公司发明了一种"半透过型"多孔石墨双极板，该双极板可以完成气体阻隔和电的传导等作用，同时，在电池运行时允许液态水直接从石墨微孔中透过而得到移除。与传统的液态水随气体尾排移除的方式相比，这种排水技术称为静态排水，而传统排水技术称为动态排水。本课题围绕着静态排水技术的燃料电池开展膜电极内部气液传输特性研究，考察排水方式的改变对电极毛细孔中的传质过程的影响，以及对电池输出性能的影响等;设计可视燃料电池结构，结合电势探针测试方法，利用阻抗等分析手段研究静态排水燃料电池中膜电极与双极板界面处的液滴运动特性，对比分析不同排水方式下液态水的移除效率。分析膜电极的微观结构对静态排水燃料电池输出性能的影响，进而优化电极结构，开发出适用于静态排水技术的膜电极，性能达到0.76 V@500 mA/cm2，项目对燃料电池的在航空、航天、交通等领域的发展有重要意义。