Effects of Cathode Gas Diffusion Layer Configuration on the Performance of Open Cathode Air-Cooled Polymer Electrolyte Membrane Fuel Cell

Abstract

The design of a gas diffusion layer (GDL) is an effective way to manage water transport, thus improving the performance of air-cooled fuel cells. In the present study, three group designs of GDL with polytetrafluoroethylene (PTFE)—uniformly doped, in-planed sandwich doped and through-plane gradient doped—are proposed, and their effects on the performance of air-cooled fuel cells are explored by numerical simulation. The distribution of key physical quantities in the cathode catalyst layer (CCL), current density and the uniformity of current density distribution in the CCL were analyzed in detail. The results show that properly reducing the amount of PTFE in GDL is beneficial to promoting the water retaining capacity of air-cooled fuel cells, and then improving the performance of fuel cells. The performance of the in-plane sandwich GDL design cannot exceed the design with 10% PTFE uniformly doped, and this design will aggravate the uneven distribution of current density in CCL. Compared with the design of GDL with 40% PTFE uniformly doped, the current density can be improved by 22% when operating at 0.6 V by gradient increasing the PTFE content in GDL from the GDL/MPL interface to the gas channel. Furthermore, this design can maintain as good a current density uniformity as uniformly doping schemes.

Non-Conventional Hybrid Microporous Layers for Enhanced Performance and Durability of PEM Fuel Cells

“…Several technological efforts are continuously spent to develop advanced materials for enhancing the performance of such devices in terms of output power density and overall efficiency [2][3][4][5][6]. Various studies have proved that the water management of PEMFCs is crucial for a proper and effective operation, particularly for the cathodic compartment [7][8][9], and the gas diffusion medium (GDM) is the most relevant component in this regard. It is inserted between the flow field of the bipolar plate and the electrode, and it is formed by a macroporous carbon-fiber-based substrate (gas diffusion layer, GDL) and a microporous layer (MPL).…”