Water management improvement in PEM fuel cells via addition of PDMS or APTES polymers to the catalyst layer.

Hande Ungan,Ayşe Bayrakçeken Yurtcan

doi:10.3906/kim-2002-49

Abstract

Water management is one of the obstacles in the development and commercialization of proton exchange membrane fuel cells (PEMFCs). Sufficient humidification of the membrane directly affects the PEM fuel cell performance. Therefore, 2 different hydrophobic polymers, polydimethylsiloxane (PDMS) and (3-Aminopropyl) triethoxysilane (APTES), were tested at different percentages (5, 10, and 20 wt.%) in the catalyst layer. The solution was loaded onto the surface of a 25 BC gas diffusion layer (GDL) via the spraying method. The performance of the obtained fuel cells was compared with the performance of the commercial catalyst. Characterizations of each surface, including different amounts of PDMS and APTES, were performed via scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) analyses. Molecular bond characterization was examined via Fourier transform infrared spectroscopy (FTIR) analysis and surface hydrophobicity was measured via contact angle measurements. The performance of the fuel cells was evaluated at the PEM fuel cell test station and the 2 hydrophobic polymers were compared. Surfaces containing APTES were found to be more hydrophobic. Fuel cells with PDMS performed better when compared to those with APTES. Fuel cells with 5wt.% APTES with a current density of 321.31 mA/cm 2 and power density of 0.191 W/cm 2 , and 10wt.% PDMS with a current density of 344.52 mA/cm 2 and power density of 0.205 W/cm 2 were the best performing fuel cells at 0.6V.

Highlights

Green energy has become the lifeblood of society and the economy
Silicon (Si) obtained for the HP-5, HP10, and HP-20 was a result of silane groups in the structure of the PDMS polymer.The results of the analysis proved that the catalyst inks were successfully loaded onto gas diffusion layer (GDL) surfaces
2 new polymers that contributed to water management were conducted as alternatives to the hydrophobic polymers traditionally used in PEM fuel cells

Summary

Introduction

Green energy has become the lifeblood of society and the economy Negative effects, such as environmental pollution, deterioration of the ecological balance, and the effect of greenhouse gases, have led scientists to search for alternative, renewable, low-carbon emission energies.Proton exchange membrane fuel cells (PEMFCs), which have the most basic use in hydrogen energy systems, are considered to be a very promising technology for converting chemical energy into electrical energy[1,2]. In the case of using hydrogen as fuel, only water and heat are produced as an outcome product, zero or probably very low carbon emissions might be obtained. Harmful emissions, such as nitrogen dioxide, sulfur dioxide, or carbon monoxide, would not pass on [3]. Fuel cells are quiet technology because they do not have moving parts, so they are ideal for use in mobile applications, hospitals, mobile phones, and laptops [6]

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