Straightforward integration of microporous layer for enhanced performance in proton-exchange membrane water electrolysis systems

초록

As a key technology to address the output variability issue of renewable energy for combating global warming, proton-exchange membrane water electrolysis (PEMWE), which enables flexible operation, is gaining attention as the most suitable alternative. However, PEMWE systems require performance improvements due to mass transport limitations in high current regions and a small contact area between the porous transport layer (PTL) and the electrodes. To address these limitations, various methods for introducing microporous layers (MPLs), such as vacuum coating, have been developed. This study investigated a more straightforward integration approach in which a sintered titanium sheet, serving as the MPL, is directly inserted between the anode and PTL during hot-pressing, without complex fabrication processes. An electrochemical analysis confirmed that an MPL with a porosity of 47% and a thickness of 40 mu m significantly reduced the mass transport overpotential and enhanced the current density by up to 24% at 2.2 V, while an SEM analysis showed improved interfacial contact with the anode. This indicates that directly applying MPL provides results equivalent to the effectiveness of MPL demonstrated in previous studies. Thus, this method is considered a valuable approach for rapidly screening MPLs for porosity and thickness to ensure performance improvement.

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