Influence of PTFE on Electrode Structure for Performance of PEMFC and 10-Cells Stack

• Published in: Chinese journal of mechanical engineering Vol. 25; no. 6; pp. 1171 - 1175
• Main Authors: Lin, Rui, Zhao, Tiantian, Zhang, Haiyan, Cao, Chunhui, Li, Bing, Ma, Jianxin
• Format: Journal Article
• Language: English
• Published: Beijing Chinese Mechanical Engineering Society 01.11.2012; Springer Nature B.V; Clean Automotive Engineering Center, Tongji University, Shanghai 201804, China; School of Automotive Studies, Tongji University, Shanghai 201804, China%School of Resource and Environmental Engineering, East China University of Science of Technology,Shanghai 200237, China%Clean Automotive Engineering Center, Tongji University, Shanghai 201804, China
• Edition: English ed.
• Subjects: Automobile industry; Catalysis; Catalysts; Cathodes; Coated electrodes; Diffusion layers; Electrical Machines and Networks; Electrochemical analysis; Electrochemical impedance spectroscopy; Electrode polarization; Electrodes; Electronics and Microelectronics; Engineering; Engineering Thermodynamics; Fuel cells; Gaseous diffusion; Heat and Mass Transfer; Instrumentation; Machines; Manufacturing; Mass transfer; Mechanical Engineering; Organic chemistry; Performance enhancement; Polytetrafluoroethylene; Power Electronics; Processes; Proton exchange membrane fuel cells; PTFE; Scanning electron microscopy; Theoretical and Applied Mechanics; Water management; 催化剂层; 扫描电子显微镜; 气体扩散层; 电化学性能; 电极结构; 电池组; 质子交换膜燃料电池; scanning electron microscopy; proton exchange membrane fuel cell; electrochemical impedance spectroscopy; fuel cell stack; poly-tetrafluoroethylene
• ISSN: 1000-9345; 2192-8258
• DOI: 10.3901/CJME.2012.06.1171

Water plays a critical role on the performance, stability and lifetime of proton exchange membrane fuel cells（PEMFCs）. The addition of poly tetrafluoroethylene（PTFE） to the gas diffusion layer, especially, the cathode side, would optimize the transportation of water, electron and gas and thus improve the performance of the fuel cell. But until now, the studies about directly applying the PTFE to the catalyst layer are rarely reported. In this paper, the membrane electrode is fabricated by using directly coating catalyst to the membrane method（CCM） and applying PTFE directly to the cathode electrode catalyst layer. The performance of the single cell is determined by polarization curves and durability tests. Electrochemical impedance spectroscopy（EIS） and scanning electron microscopy（SEM） techniques are used to characterize the electrochemical properties of PEMFC. Also the performance of a 10-cells stack is detected. Combining the performance and the physical-chemistry characterization of PEMFC shows that addition of appropriate content of PTFE to the electrode enhances the performance of the fuel cell, which may be due to the improved water management. Addition of appropriate content of PTFE enhances the interaction between the membrane and the catalyst layer, and bigger pores and highly textured structure form in the MEA, which favors the oxygen mass transfer and protons transfer in the fuel cell. While superfluous addition of PTFE covers the surface of catalysts and hindered the contact of catalyst with Nation, which leads to the reduction of electrochemical active area and the decay of the fuel cell performance. The proposed research would optimize the water management of the fuel cell and thus improve the performance of the fuel cell.