Speaker
Description
4D X-ray tomographic microscopy (XTM) offers the possibility to obtain detailed insights into the water removal process through gas diffusion layers (GDL) of polymer electrolyte fuel cells (PEFC) [1-4]. Recent work on droplet formation and detachment cycle [5, 6] has provided insights into the inter-action between a percolating water cluster feeding a droplet on the GDL surface and allowed the cal-culation of the capillary pressure in the water cluster via surface curvature analysis. The work of Mu-larzcyk et al. [6] was limited to the analysis of a single percolating water cluster using a small active area of 0.005 mm2. Here we extend the previous study by using a catalyst coated membrane with 8 small active areas (0.0625 mm2) thereby, allowing the analysis of the development of multiple perco-lating water clusters, in addition to increasing statistics [7].
An operando XTM cell was imaged at the TOMCAT beamline of the Swiss Light Source with a scan rate of 1 Hz for 180 s after a current jump from OCV to 1 A/cm2 at 30°C cell temperature and 100 % relative humidity of anode and cathode feed gases. In total 11 water breakthrough points were identi-fied that percolated from the 8 isolated active areas through a Toray TGP-H-060 GDL (10 %wt PTFE). This presentation will discuss the percolation process of individual water clusters with respect to their through-plane and in-plane growth to identify correlations between the water volume, the local pore structure and the stability of the water cluster – droplet network (see Figure 1).
References
[1] J. Eller et al., ECS Transactions, 2015, 69(17), pp. 523–531
[2] Y. Nagai et al., Journal of Power Sources, 2019, 435, 226809
[3] M. Sabharwal et al., Journal of Power Sources, 2021, 489, 229447
[4] H. Xu et al., Journal of Power Sources, 2021, 490, 229492
[5] A. Mularczyk et al., Journal of the Electrochemical Society, 2020, 167(8), 084506
[6] A. Mularczyk et al., ACS Applied Material Interfaces, 2021, 13, 34003-34011
[7] T. Dörenkamp et al., ECS Transactions, 2021, 104, 75
| Participation | In-Person |
|---|---|
| Country | Switzerland |
| Energy Transition Focused Abstracts | This abstract is related to Energy Transition |
| MDPI Energies Student Poster Award | No, do not submit my presenation for the student posters award. |
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