Temperature dependent water transport mechanism in gas diffusion layers revealed by subsecond operando X-ray tomographic microscopy

JOURNAL OF POWER SOURCES

卷:490

Article

Xu, Hong¹  Nagashima, Shinya²  Nguyen, Hai P.²  Kishita, Keisuke²  Marone, Federica³  Buchi, Felix N.¹  Eller, Jens¹ 

[1] Paul Scherrer Inst, Electrochem Lab, CH-5232 Villigen, Switzerland

[2] Toyota Motor Europe, Adv Technol, B-1930 Zaventem, Belgium

[3] Paul Scherrer Inst, Photon Sci Dept, CH-5232 Villigen, Switzerland

关键词: Polymer electrolyte fuel cell;    Gas diffusion layer;    Water transport;    Operando X-ray tomographic microscopy;   

DOI  :  10.1016/j.jpowsour.2021.229492

来源: Elsevier

【 摘 要 】

The product water of polymer electrolyte fuel cells (PEFCs) has to pervade the gas diffusion layer (GDL) and can lead to shortages of educt gas diffusion pathways to the catalyst layer hence to significant performance losses. Here we report on efforts made to enable subsecond and submicron operando X-ray tomographic microscopy (XTM) over a wide range of cell operating temperatures. The short XTM scan times allow to quantify the contributions of capillary-fingering and phase-change-induced flow on the overall water transport inside the cathode GDL at two different cell operating temperatures of 40 degrees C and 80 degrees C during a current ramp-up process. The results suggest that phase-change-induced water transport dominates the initial increase of saturation levels at typical automotive PEFC operating temperatures of about 80 degrees C, whereas capillary-fingering driven transport dominates the development of saturation from the beginning to stagnating stage at 40 degrees C.

【 授权许可】

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