Experimental Investigation and Numerical Determination of Custom Gas Diffusion Layers to Understand Water Transports in PEMFC
In this study, the different designs of GDL with the introduction of two micro porous layers were investigated on PEMFC performance through characterization of their materials and structures as shown in Fig. 1. This new design of GDLs has been modified from standard AvCarb GDLs by adding two micro porous layers. Each set has been treated with two different methods in order to provide two different value of diffusivity. Polarization curves were collected at different designs of GDL as shown in Fig. 2. Further, the internal fuel cell resistance was measured by high frequency resistance (HFR) technique at 1000 Hz. Pore size distribution (PSD) data of the different GDLs were reported and analyzed. It is well known that tortuosity (τ) and porosity (ε) are two important parameters to relate free-stream properties with the actual mass transport in GDL . The relationship of tortuosity (τ) and porosity (ε) was measured as the MacMullin number.
In addition to these experiments, we present a computational fluid dynamic (CFD) analysis of the PEMFC operation with provided GDL characterization information, speciﬁcally the MacMullin number and PSD to compare with experiment data. The CFD prediction of current density distribution and gas/water transports in PEMFC will be used to understand the effect of these new designs of GDL.
This project is supported by the Department of Energy Contract Grant# DE-EE0000471
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