Fuel Cells

Material modelling and property characterization for Fuel Cells with GeoDict

The membrane electrode assembly (MEA) of a proton exchange membrane (PEM) consists of various porous layers: gas diffusion layer (GDL) [1, 2, 3, 4, 5, 6, 7, 10], micro porous layer (MPL) [8, 9], catalyst layer (CL) [11, 12] and membrane. GeoDict is used by fuel cell developers to generate detailed three-dimensional geometric models and characterize a number of material properties of these models, with the goal of optimizing each of the layers to its requirements and improving the performance of the cell.

The fuel cell layer models are created with the FiberGeo and GrainGeo modules. The central topic in fuel cell research, water management and the resulting two-phase fluid flow properties, are also addressed with GeoDict. For this, the water is virtually distributed in the structures using the SatuDict module, and various solvers for partial differential equations are applied on the resulting partially saturated structures. Afterwards, the solvers from the GeoDict modules FlowDict, DiffuDict, and ConductoDict can be used to characterize fluid flow, diffusion, and thermal and/or electrical conductivity .

Besides two large publically funded projects for fuel cells (PEM-Design and PemCad) during which the early research stages for GeoDict for fuel cell simulations was done, a number of companies currently use SatuDict and other GeoDict modules for their Research & Development on GDL and MPL in automotive applications. Additionally, the structures generator and property prediction modules in GeoDict can be used for the material research for batteries [13, 14], for example in System Research for Electromobility.

Gas Diffusion Layer (GDL), 3D reconstruction from µCT scannes.
Water in GDL
Water distribution inside the GDL
Flow in GDL
Fluid flow in the pores of the GDL