Majasan, JO;
Iacouiello, F;
Cho, JIS;
Maier, M;
Lu, X;
Neville, TP;
Dedigama, I;
... Brett, DJL; + view all
(2019)
Correlative study of microstructure and performance for porous transport layers in polymer electrolyte membrane water electrolysers by X-ray computed tomography and electrochemical characterization.
International Journal of Hydrogen Energy
, 44
(36)
pp. 19519-19532.
10.1016/j.ijhydene.2019.05.222.
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Microstructure-Performance relationship of PTLs in PEMWE_Accepted.pdf - Accepted Version Download (1MB) | Preview |
Abstract
The porous transport layer (PTL) in polymer electrolyte membrane water electrolysers (PEMWEs) has the multiple roles of delivering water to the electro-catalyst, removal of product gas, and acts as a conduit for electronic and thermal transport. They are, thus, a critical component for optimized performance, especially at high current density operation. This study examines the relationship between the microstructure and corresponding electrochemical performance of commonly used titanium sinter PTLs. Four PTLs, with mean pore diameter (MPD) ranging from 16 μm to 90 μm, were characterized ex-situ using scanning electron microscopy and X-ray computed micro-tomography to determine key structural properties. The performance of these PTLs was studied operando using polarization and electrochemical impedance spectroscopy. Results showed that an increase in mean pore size of the PTLs correlates to an increase in the spread and multimodality of the pore size distribution and a reduction in homogeneity of porosity distribution. Electrochemical measurements reveal a strong correlation of mean pore size of the PTLs with performance. Smaller pore PTLs showed lower Ohmic resistance but higher mass transport resistance at high current density of 3.0 A cm−2. A non-monotonic trend of mass transport resistance was observed for different PTLs, which suggests an optimal pore size beyond which the advantageous influence of macroporosity for mass transport is diminished. The results indicate that maximizing contact points between the PTL and the catalyst layer is the overriding factor in determining the overall performance. These results guide PTL design and fabrication of PEMWEs.
| Type: | Article |
|---|---|
| Title: | Correlative study of microstructure and performance for porous transport layers in polymer electrolyte membrane water electrolysers by X-ray computed tomography and electrochemical characterization |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.ijhydene.2019.05.222 |
| Publisher version: | https://doi.org/10.1016/j.ijhydene.2019.05.222 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Science & Technology, Physical Sciences, Technology, Chemistry, Physical, Electrochemistry, Energy & Fuels, Chemistry, Polymer electrolyte membrane water electrolyser, Pore size, Two-phase flow, Porous transport layer, Electrochemical impedance spectroscopy, X-ray computed micro-tomography, LIQUID/GAS DIFFUSION LAYERS, HYDROGEN-PRODUCTION, FLOW VISUALIZATION, CURRENT COLLECTORS, PEM ELECTROLYSIS, FUEL-CELLS, EFFICIENCY, ASSEMBLIES, MANAGEMENT, REGIME |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Chemical Engineering |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10081085 |
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