A key breakthrough in hydrogen fuel cells: enhancing macroscopic mass transport properties by tailoring the porous microstructure

Project Information

HyPoStruct

Grant agreement ID: 790744

DOI

10.3030/790744

Project closed

EC signature date 26 March 2018

Start date 9 January 2019

End date 8 January 2021

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 173 857,20

EU contribution

€ 173 857,20

Coordinated by

CHALMERS TEKNISKA HOGSKOLA AB
Sweden

Periodic Reporting for period 1 - HyPoStruct (A key breakthrough in hydrogen fuel cells: enhancing macroscopic mass transport properties by tailoring the porous microstructure)

Reporting period: 2019-01-09 to 2021-01-08

Summary of the context and overall objectives of the project

The present project investigates the transport properties of two phase flows in fuel cells porous materials with an innovative bottom-up approach: understanding from pore-scale microscopic simulations the main mechanisms of water transport and extracting the effective transport properties, in order to achieve optimised electrodes designs.
The project aims at improving the performance of polymer electrolyte fuel cells, by optimising the electrode performance, from a fluid-dynamic and water management perspective. The goal is to understand the mechanisms of water transport within fuel cells electrodes, in order to identify innovative optimal design that would allow a boost in fuel cells competitiveness and performance.This is desired technological step in order to speed up the transition to fossil-free transportation.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The geometry of a commercially available electrodes has been reconstructed via X-ray computed tomography and used as input for two-phase simulations. The study has unveiled different regimes responsible for water transport, occurring in the cell during operation and flooding of the electrode. At the pore-scale, the microstructuctural characteristic of the electrodes determine an unstable dynamics of water transport, which can be beneficial to the fast removal of water. A preferable design of the electrode would be characterised by a positive gradient in the pore sizes along the through-plane direction.

Results of this study have been published in:

Farzaneh, M., Ström, H., Zanini, F., Carmignato, S., Sasic, S., & Maggiolo, D. (2021). Pore-Scale Transport and Two-Phase Fluid Structures in Fibrous Porous Layers: Application to Fuel Cells and Beyond. Transport in Porous Media, 136(1), 245-270.

and have been disseminated at the following international scientific conferences:

The 72nd Annual Meeting of the American Physical Society’s Division of Fluid Dynamics (DFD), held in Seattle, Washington on November 23-26, 2019

INTERNATIONAL COUPLED PROBLEMS 2019, ECCOMAS \& IACM 8th edition of the International CONFERENCES Conference on Computational Methods for Coupled Problems in Science and Engineering, 3-5 June 2019 in Sitges, Spain.

The 10th International Conference on Multiphase Flow (ICMF), held in Rio de Janeiro, Brazil, May 19-24, 2019

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The project has unveiled the microscopic water transport occurring within commercially available electrodes. Such an analysis has contributed to expand the previous knowledge about two-phase transport in porous media, in particular, by providing insights into the way water is transported in carbon-fiber based electrodes. The microstructure-induced curvatures of the two-phase interfaces within the medium plays a key role, since they determine the flow resistance. An effective capillary pressure have been measured in neutrally wetted electrodes, which is purely induced by the microstructure, in contrast to the view that predicts a flat interface for neutrally wetted solid surfaces.

Methodology for the characterisation of mass trasnport properties of an eletcrode