超声喷涂法制备PEMFC膜电极研究

Preparing PEMFC Electrodes by Ultrasonic-Spray Technique

介绍了超声喷涂技术在制备质子交换膜燃料电池(PEMFC)膜电极中的应用。对喷涂数据的分析表明,超声喷涂技术喷涂重复性和稳定性好,浆料利用率高。对膜电极进行形貌分析,显示膜电极表面均匀且颗粒分散性良好,微孔层(MPL)和催化层(CL)呈立体孔隙结构,有利于减少传输电阻,形成有效的三相反应区。保持阴极铂载量为0.55 mg·cm^(-2),阳极降载量实验表明,在极低阳极铂载量下,膜电极仍具有良好的性能。在50℃,无外加湿,氢空测试条件下,阳极铂载量为0.05 mg·cm^(-2)时,最高功率密度为370 m W·cm^(-2),而单位阳极铂质量的比功率达7.39 W·mg^(-1),催化剂利用率高。氢闭端400 m A·cm^(-2)长时放电实验表明,0.05 mg·cm^(-2)膜电极仍然表现出与0.30 mg·cm^(-2)膜电极相当的性能。实验表明进一步降低膜电极铂载量是可行的。

A novel ultrasonic-spray method for preparing gas diffusion electrodes （GDEs） for proton exchange membrane fuel cells （PEMFCs） was described. The analysis of spraying data indicated that the ultrasonic spraying technology showed good repeatability, satisfying stability and high utilization of catalyst ink. The analysis of morphology showed that the membrane electrode had homogeneous surface and the catalyst particles were dispersed well. The microporous carbon layer （MPL） and catalyst layer （CL） had stereo pore structure, so that the transmission resistance could be reduced and the three-phase reaction zone could be formed effectively. When the Pt loading at cathode was kept 0.55 mg cm -2, it was found that the GDEs prepared by ultrasonic-spray method exhibited excellent per- formances at low Pt loadings. The measurement was conducted at 50 ℃ without any humidification at the anode and cathode sides using H2 and air as fuel and oxidant respectively. The Pt loading at cathode was kept 0.55 mg cm-2, GDEs with a platinum loading of 0.05 -2 mg.cm at anode exhibited a peak power density of 370 mW.cm -2, and the peak power per anode Pt loading reached 7.39 W mg -2. The chronoamperometry experiment at 400 mA cm-2 under dead-end anode mode also showed that GDEs with a platinum loading of 0. 05 mg.cm-2 exhibited comparable performance with 0.30 mg cm-2 one. It was highly practicable to reduce the Pt loading of the GDEs further.