Multiscale stochastic modeling of microporous layers and bi-layer gas diffusion media for polymer electrolyte fuel cells

Abstract

The microporous layer (MPL) is placed between the catalyst layer and gas diffusion layer (GDL) substrate to enhance mass transport, performance, and durability of fuel cells. Considering the significant experimental challenges in the prototyping and characterization of MPLs, the objective of the present work is to develop a multiscale stochastic modeling framework for MPLs and complete MPL-coated bi-layer GDLs. A comprehensive range of MPLs is considered, including carbon nanoparticle and graphite particle-based materials. Following experimental validation, the modeling framework is applied to simulate the effects of MPL morphology and composition on the salient transport properties of MPLs and full GDLs. The MPL morphology is shown to have a major, controlling influence on the overall GDL properties and can therefore be used as a design strategy for enhanced transport within the membrane electrode assembly of the fuel cell. Additionally, the validated multiscale modeling approach is reliable and flexible enough to be applied as a virtual design tool for MPL and GDL prototyping assignments to reduce the cost and time of the design cycle.