Two-Phase Flow in Porous Electrodes of Proton Exchange Membrane Fuel Cell

Abstract

Water management in porous electrodes bears significance due to its strong potential in determining the performance of proton exchange membrane fuel cell. In terms of porous electrodes, internal water distribution and removal process have extensively attracted attention in both experimental and numerical studies. However, the structural difference among the catalyst layer (CL), microporous layer (MPL), and gas diffusion layer (GDL) leads to significant challenges in studying the two-phase flow behavior. Given the different porosities and pore scales of the CL, MPL, and GDL, the model scales in simulating each component are inconsistent. This review emphasizes the numerical simulation related to porous electrodes in the water transport process and evaluates the effectiveness and weakness of the conventional methods used during the investigation. The limitations of existing models include the following: (i) The reconstruction of geometric models is difficult to achieve when using the real characteristics of the components; (ii) the computational domain size is limited due to massive computational loads in three-dimensional (3D) simulations; (iii) numerical associations among 3D models are lacking because of the separate studies for each component; (iv) the effects of vapor condensation and heat transfer on the two-phase flow are disregarded; (v) compressive deformation during assembly and vibration in road conditions should be considered in two-phase flow studies given the real operating conditions. Therefore, this review is aimed at critical research gaps which need further investigation. Insightful potential research directions are also suggested for future improvements.

Air‐liquid water transport phenomena in a proton exchange membrane fuel cell cathode with a leaf‐like flow field design

“…Because of the complex fibrous structure of the gas diffusion layer, there are several limitations and challenges in the 3D multiphase simulation of the liquid transport behavior. 57 It includes the difficulty of reconstructing the porous layer fibrous structure as geometric models and the requirement of extensive computational time and resources for a full-scale 3D multiphase simulation of the microstructure. Furthermore, this study focuses mainly on the general liquid transportation inside the biomimetic flow field instead of the complex two-phase flows in the microstructure of the porous layer.…”

Pore-Scale Investigation of Coupled Two-Phase and Reactive Transport in the Cathode Electrode of Proton Exchange Membrane Fuel Cells

“…To complement the experimental issues, numerical modeling has been widely employed to study the two-phase flow in the electrodes of PEM fuel cells [5,17]. The volume-of-fluid (VOF) method [18], pore network (PN) model [19], and lattice Boltzmann model (LBM) [20] are currently the most popular numerical methods.…”

Impact of Micro-Porous Layer Cracks Morphology on Two-Phase Behaviors in Proton Exchange Membrane Fuel Cell

“…In recent years, proton exchange membrane (PEM) fuel cells have attracted much attention due to the high conversion efficiency, zero emissions, and quick startup. PEM fuel cells convert the chemical energy into electrical energy through the electrochemical reaction of hydrogen and oxygen, and produce pure water [1]. Excessive product water in GDL may block the gas diffusion pathway and result in severe water flooding, but the membrane humidity should also be maintained to avoid a low ion conductivity.…”