Fabrication of high-performance gas-diffusion-electrode based membrane-electrode assemblies

JOURNAL OF POWER SOURCES

卷:450

Article

Mauger, Scott A.¹  Pfeilsticker, Jason R.¹  Wang, Min¹  Medina, Samantha²  Yang-Neyerlin, A. C.^1,2  Neyerlin, K. C.¹  Stetson, Caleb²  Pylypenko, Svitlana^1,2  Ulsh, Michael¹ 

[1] Natl Renewable Energy Lab, Chem & Nanosci Ctr, Golden, CO 80401 USA

[2] Colorado Sch Mines, Dept Chem, Golden, CO 80401 USA

关键词: Gas diffusion electrodes;    Membrane electrode assembly;    Fuel cells;    Fabrication;   

DOI  :  10.1016/j.jpowsour.2019.227581

来源: Elsevier

【 摘 要 】

This work demonstrates the fabrication and processing steps required to produce high performance fuel cell membrane electrode assemblies (MEAs) based on spray-coated gas-diffusion electrodes (GDEs). It is demonstrated that coating the catalyst layer with a thin layer of ionomer and then hot pressing the GDEs to the membrane is required to achieve comparable catalyst activity and air performance to catalyst-coated-membrane MEAs. We show that there is a critical amount of ionomer required to achieve maximized performance. Using electron microscopy, we show that the combination of the ionomer overlayer and hot-pressing bonds the catalyst layer to the membrane, increasing the interfacial contact area and quality of this interface. We also find that the ionomer overlayer smooths the surface of the GDE and provides increased contact area between the GDE and the membrane. Additionally, we demonstrate that much less ionomer is required for high-performance than has been previously reported. Through model fitting of electrochemical impedance spectroscopy, we show that this improvement in the catalyst layer - membrane interface reduces the effective catalyst layer resistance, which reduces Ohmic losses and increases catalyst utilization.

【 授权许可】

Free