Compress effects on porosity, gas-phase tortuosity, and gas permeability in a simulated PEM gas diffusion layer

Abstract

Summary Among the parameters to take into account in the design of a proton exchange membrane fuel cell (PEMFC), the energy conversion efficiency and material cost are very important. Understanding in deep the behavior and properties of functional layers at the microscale is helpful for improving the performance of the system and find alternative materials. The functional layers of the PEMFC, i.e., the gas diffusion layer (GDL) and catalyst layer, are typically porous materials. This characteristic allows the transport of fluids and charges, which is needed for the energy conversion process. Specifically, in the GDL, structural parameters such as porosity, tortuosity, and permeability should be optimized and predicted under certain conditions. These parameters have effects on the performance of PEMFCs, and they can be modified when the assembly compression is effected. In this paper, the porosity, gas‐phase tortuosity, and through‐plane permeability are calculated. These variables change when the digitally created GDL is under compression conditions. The compression effects on the variables are studied until the thickness is 66% of the initial value. Because of the feasibility to handle problems in the porous media, the fluid flow behavior is evaluated using the lattice Boltzmann method. Our results show that when the GDL is compressed, the porosity and through‐plane permeability decrease, while the gas‐phase tortuosity increases, i.e., increase the gas‐phase transport resistance. Copyright © 2015 John Wiley & Sons, Ltd.

Modeling of inhomogeneous compression effects of porous GDL on transport phenomena and performance in PEM fuel cells

“…The diffusion coefficient is important, because it determines the local reactant/product distribution. The effect of compression on the diffusion coefficient can be evaluated by Eqs (10) to (13), where this variable is a function of the porous properties, that is, porosity and tortuosity. The importance of this effect was experimentally studied by Nitta et al to determine the gas permeability of the GDL for inhomogeneous compression.…”

A Detailed Analysis of Internal Resistance of a PEFC Comparing High and Low Humidification of the Reactant Gases

“…In addition, the reduction of platinum can be achieved analyzing transport phenomena inside PEFCs. A study to predict different transport parameters in a GDL is presented in Espinoza et al (2015).…”

An Assessment on Additive Manufacturing Technique to Fabricate Integral PEM Fuel Cell/Electrolyser Component

“…It anatomically comprises of two layers, a hydrophobic agent (Poly Tetra Fluoro Ethylene) and a microporous layer made of Toray carbon paper or a carbon cloth that is covered with a microporous layer. Several GDL microscopic variables such as porosity, tortuosity, and permeability impact the behaviour of the fuel cells [11][12][13][14]. Figure 4 lists the two widely used conventional gas diffusion layer namely Carbon paper and Carbon cloth.…”