Two-phase flow behaviour and performance of polymer electrolyte membrane electrolysers: Electrochemical and optical characterisation

Majasan, J.; Cho, J.I.S.; Dedigama, Ishanka; Tsaoulidis, Dimitrios; Shearing, Paul R.; Brett, Dan J. L.

doi:10.1016/j.ijhydene.2018.07.003

Cited by 109 publications

(60 citation statements)

References 45 publications

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“…The parallel flow-fields were designed with diagonally opposing inlet and outlet, as described by Majasan et al [34]. In these Z-type flow-fields a non-uniform distribution of water flow velocity and pressure is observed.…”

Section: Pemwe Cellmentioning

confidence: 99%

“…To do this, the land locations are focused on as the open flow channels are dominated by relatively unstable twophase flow with time-varying bubble dynamics, which precludes accurate analysis of the effective water thickness in the LGDL. Indeed, flow dynamics within channels have been extensively studied using optical cells [34,[40][41][42], but it is the particular ability of neutron imaging to examine water under lands and within porous structures that is exploited here [17,19].…”

Section: Neutron Imaging and Image Analysismentioning

confidence: 99%

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Mass transport in polymer electrolyte membrane water electrolyser liquid-gas diffusion layers: A combined neutron imaging and X-ray computed tomography study

Maier

Dodwell

Ziesche

et al. 2020

Journal of Power Sources

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The increasing use of intermittent renewable energy sources calls for novel approaches to large-scale energy conversion and storage. Hydrogen can be readily stored and produced from renewable sources using polymer electrolyte membrane water electrolysers (PEMWEs). Mass transport of water and product gas in the liquid-gas diffusion layer (LGDL) is critical for PEMWE performance, particularly at high current densities. In this work, neutron radiography is deployed to measure the spatial distribution of water within three different LGDLs, while X-ray micro-computed tomography (XCT) is used to characterize the microstructure of the LGDL materials. The combination of these two techniques yields valuable insight into water transport within the LGDL. Significant local water heterogeneity is observed and a link between flow-field geometry/location and LGDL mass transport is identified. It is further shown that the pore volume in these LGDLs is significantly under-utilized, pointing the way towards design optimisation of LGDL materials and architectures.

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Section: Pemwe Cellmentioning

confidence: 99%

Section: Neutron Imaging and Image Analysismentioning

confidence: 99%

Mass transport in polymer electrolyte membrane water electrolyser liquid-gas diffusion layers: A combined neutron imaging and X-ray computed tomography study

Maier

Dodwell

Ziesche

et al. 2020

Journal of Power Sources

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“…A Photron FASTCAM SA1 high-speed camera with a Tokina MACRO 100 F2.8 D lens was used to image the full flow-field on the anode side (1024 × 1024 pixel resolution, 2,000 frames per second, 5.46 s acquisition). The transparent end-plates allowed for direct optical access to the flow-field (Dedigama et al, 2014;Majasan et al, 2018).…”

Section: High-speed Imagingmentioning

confidence: 99%

Diagnosing Stagnant Gas Bubbles in a Polymer Electrolyte Membrane Water Electrolyser Using Acoustic Emission

et al. 2020

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The use of acoustic emission as a low-cost, non-destructive, and operando diagnostic tool has been demonstrated for a range of electrochemical energy conversion and storage devices, including polymer electrolyte membrane water electrolysers (PEMWEs) and fuel cells. In this work, an abrupt change in acoustic regime is observed during operation of a PEMWE as the current density is increased from 0.5 to 1.0 A cm −2. This regime change is marked by a sudden drop in the number of acoustic hits, while hit duration, amplitude, and energy increase significantly. It is found that the change in acoustic regime coincides with a significant extension of the stagnant bubble region in the flow channels of the PEMWE, observed with high-speed optical imaging. These results demonstrate that acoustic emission can be used effectively as an operando diagnostic tool to monitor bubble formation (two-phase flow conditions) in PEMWEs, facilitating rapid testing or prototyping, and contributing to operational safety.

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“…The single PEMWE cell used in this study has an electrode area of 9 cm 2 (3 × 3 cm) and has been detailed in a previous paper [39]. The flow-field plate for the anode and cathode sides were fabricated from 3 mm-thick commercial grade titanium.…”

Section: Ptl Samples and Pemwe Cellmentioning

confidence: 99%

“…The cathode-side flow plate consist of a single-serpentine flow channel (1.76 mm width, 3 mm depth, and 1.76 mm land width), while the anode-side flow field consist of nine parallel channels (1.76 mm width, 3 mm depth, and 1.76 mm land width). The MEA is the same as that used in our previous study [39], consisting of 3 mg cm -2 iridium/ruthenium oxide on the anode and 0.6 mg cm -2 platinum black on the cathode plated either side of a Nafion 115 membrane. Untreated Toray carbon-paper (Toray 090) was used as the PTL on the cathode side.…”

Section: Ptl Samples and Pemwe Cellmentioning

confidence: 99%

Correlative study of microstructure and performance for porous transport layers in polymer electrolyte membrane water electrolysers by X-ray computed tomography and electrochemical characterization

Majasan

Iacoviello

Cho

et al. 2019

International Journal of Hydrogen Energy

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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.

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Two-phase flow behaviour and performance of polymer electrolyte membrane electrolysers: Electrochemical and optical characterisation

Cited by 109 publications

References 45 publications

Mass transport in polymer electrolyte membrane water electrolyser liquid-gas diffusion layers: A combined neutron imaging and X-ray computed tomography study

Mass transport in polymer electrolyte membrane water electrolyser liquid-gas diffusion layers: A combined neutron imaging and X-ray computed tomography study

Diagnosing Stagnant Gas Bubbles in a Polymer Electrolyte Membrane Water Electrolyser Using Acoustic Emission

Correlative study of microstructure and performance for porous transport layers in polymer electrolyte membrane water electrolysers by X-ray computed tomography and electrochemical characterization

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