Optimization of Gas Diffusion Layers with High-Corrosion Resistance for Pemwe

 

An advanced polymer electrolyte membrane water electrolyzer (PEMWE), which is a reverse PEM fuel cell (PEMFC), has been an effective energy storage medium by producing hydrogen/oxygen from water with electricity from renewable energy sources because of its distinguished efficiency, high energy density, compact and large capacity. In a PEMWE, a gas diffusion layer (GDL) is located between the catalyst layer and the current collecting flow field. The purpose of the GDL is to transport electrons, heat and reactants/products to and from the catalyst layer with minimum voltage, current, thermal, interfacial, and fluidic loss. Carbon materials (carbon paper or carbon cloth), which are typically used in PEMFCs, are unsuitable for PEMWEs due to high potential of the oxygen electrode. The carbon corrosion and consumption will result in poor interfacial contacts which will degrade performance and efficiency. This presentation will highlight recent efforts to optimize the GDL properties at the anode side for high-efficiency PEMWEs. A set of GDLs with different thicknesses and a range of porosities from 30% to 80% are designed and examined with a PEMWE that was developed in lab. Both electropotential performance and impedance measurements are conducted on the different GDLs in order to evaluate the effectiveness of altering the aforementioned parameters. The microscale characterizations of all the GDLs are detailed.  From the results and metrics, an optimized set of parameters for an anode-side GDL is created.

Acknowledgements

This research is supported by the U.S. Department of Energy under Grant DE-FE0011585.