bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding Durability of Polymer Electrolyte Membrane Water Electrolyzers
Authors: Li Kui , Yu Haoran , Gawas Ramchandra , Cullen David A. , Myers Deborah J. , Kropf A. Jeremy , Sweers Matthew , Mukundan Rangachary , Spendelow Jacob S. , Komini Babu Siddharth 
Published: December 2024

Hydrogen is positioned to play a pivotal role in the future energy landscape, bolstered by the increasing adoption of renewable energy sources. The U.S. Department of Energy (DOE) has initiated the Hydrogen earth shot, with a goal of achieving a cost target of $1 per kilogram of hydrogen within a decade. Polymer electrolyte membrane water electrolyzers (PEMWE) are at the forefront of enabling hydrogen production from renewable electricity. Yet, achieving the 80000 h operational lifetime remains a critical challenge for the commercial viability of PEMWE.1 An in-depth understanding of the conditions affecting the degradation of critical PEMWE components including the catalyst layer, membrane, and porous transport layers is crucial for achieving the durability target of PEMWE.
In this study, we explore the effect of various operating conditions, such as temperature, pressure, and cycling vs. hold of voltage or current, and the membrane electrode assembly composition, including catalyst loading, membrane thickness, and incorporation of gas recombination catalyst (GRC), on degradation in PEMWE. To assess the degradation rate, our protocol involved long duration durability tests, alternating between high and low current density cycles with long holding periods and rapid cycling. Electrochemical characterization including polarization curve, electrochemical impedance spectroscopy, and cyclic voltammetry will be presented. Additionally, electron microscopy and X-ray spectroscopy analysis provides insight into changes in the catalyst layer. The second part of the study focuses on understating membrane degradation in PEMWEs. Through periodic analysis of the cathode and anode effluent water during long duration current density holds, the fluorine emission rate (FER) was estimated, a key metric for assessing membrane and ionomer loss. Preliminary investigation reveals that incorporation of GRC in the membrane reduces hydrogen crossover, thereby lowering the FER and the degradation rate. This study enhances our understanding of PEMWE degradation, offering critical data to develop accelerated stress test (AST) protocols.
Acknowledgment:
This research is supported by the U.S. Department of Energy (DOE) Hydrogen and Fuel Cell Technologies Office through the Hydrogen from Next-generation Electrolyzers of Water (H2NEW) consortium.
Reference:

Tomic, A. Z., Pivac, I., Barbir, F., Journal of Power Sources (2023) 557
How to Assess the Degradation of the PEM Water Electrolysis Anode Catalyst on a Lab Scale?
Authors: Rogler Mirjam , Wagner Richard , Thiele Simon , Suermann Michel 
Published: December 2024

Proton exchange membrane water electrolysis (PEMWE) is an established technology to produce green hydrogen. Further improvements in terms of material (cost) reduction, performance, and durability are required to meet the ramp-up targets of a large-scale production of PEMWE stacks and to reduce the levelized costs of hydrogen production. It is key to maintain or even increase the durability of the iridium-based anodic catalyst layer while further reducing its raw metal demand.
Usually, the development of novel materials used as anode catalysts is progressing faster than the evaluation under PEMWE conditions in cell and stack tests. Therefore, accelerated stress tests (ASTs) have to be developed.1, 2 ASTs are degradation mechanism-specific protocols that have a targeted and accelerated effect, and significantly reduce the required test time.
In this work, several voltage-controlled AST protocols and their application in PEMWE cell tests with various anode catalyst types and iridium loadings are analyzed. The AST protocols consist of rapid changes in the voltage between 1.9 V and either 1.25 V, open circuit voltage or 0 V. For reference the voltage is kept constant at 1.9 V. The effects of these protocols on the kinetic parameters of the oxygen evolution reaction (OER), e.g. the apparent exchange current density and the Tafel slope, are evaluated using three different methods. As state of the art, the voltage breakdown analysis (VBA) method is used and directly compared to two other methods, i.e. the constant Tafel slope (CT-VBA)3 method and the OER mass activity method. Furthermore, the influence of dynamic potential profiles on the kinetic overpotential is analyzed with an overpotential difference approach. Depending on the method used, the resulting trends for the OER kinetic parameters diverge. In doing so, we want to raise awareness about the strengths, weaknesses and limitations of each method and their impact of the respective interpretation.4

References

S. M. Alia, S. Stariha and R. L. Borup, J. Electrochem.
Soc.,
166(15), F1164-F1172 (2019).

A. Weiß, A. Siebel, M. Bernt, T.-H. Shen, V. Tileli and H. A. Gasteiger, J. Electrochem.
Soc.,
166(8), F487-F497 (2019).

M. Rogler, M. Suermann, R. Wagner, S. Thiele and J. Straub, J. Electrochem. Soc.,
170(11), 114521 (2023).

M. Rogler, et al., to be submitted.
Modeling Gas Bubbles in Water Electrolyzers across Length Scales
Authors: Davis Jonathan T. , Seung Kansas , Guo Jack , Ferron Thomas J , Aydin Fikret , Hammons Joshua Aaron , Lin Tiras Y , Kang Shinyoung 
Published: December 2024

As water electrolyzers scale to larger current densities, reactor designs must be re-evaluated to handle the subsequently high rates of gas bubble formation. Without proper transport, gas bubbles can become entrained on the electrode surface, block active sites, and hamper the flow of water and ions. These events decrease the energy efficiency of the electrolyzer, and over time can even lead to the mechanical failure of components within the device. Modeling the transport behavior of gas bubbles can guide the design of electrodes, porous transport layers, and flow fields. Gas bubble transport is notoriously complicated, however, with physical interactions spanning across several length scales and time scales. This talk explores how we can use multiscale modeling tools to deconvolute this problem and improve our understanding of gas transport in electrochemical systems. At the surface scale, we use molecular dynamics simulations to explore the relationship between nanobubbles, surface defects, and dissolved hydrogen. At the continuum scale, a volume of fluid model can be used to explore the relationship between fluid flow and macroscopic bubble transport. Using 3D printing, we can manufacture optically transparent pores to visualize the flow of bubbles to begin validating these models.
This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
Elucidating Degradation Mechanisms through Modeling of Proton-Exchange Membrane Electrolytic Cells
Authors: Karyofylli Violeta , Danner Yannik , Raman K. Ashoke , Hammacher Linus , Kungl Hans , Karl André , Jodat Eva , Eichel Rudiger-A 
Published: December 2024

Proton exchange membrane (PEM) electrolytic cells (ECs) have gained significant importance in the realm of hydrogen production. With the increasing demand for commercializing PEMECs, there is a pressing need for enhancing their performance and durability. In addition to experiments, macro-scale modeling plays a pivotal role in comprehending the multi-physics processes within PEMECs.
This presentation highlights the development of physics-based and data-based models tailored for PEMECs. They serve as the foundation for elucidating degradation mechanisms of PEMECs, aiming to prolong their lifespan and improve their efficiency for a quick technology ramp up. These models explore the electrochemical processes and transport phenomena occurring within the porous transport layers (PTLs), catalyst layers (CLs), and the PEM. The high-aspect-ratio PEMECs are well-suited for one-dimensional (1D) analysis [1-3]. The 1D analysis is implemented in Python, with COMSOL also utilized for 2D and 3D simulations.
Unfortunately, the complex nature of PEMECs as thermal, fluidic, and electrochemical systems poses challenges in accurate diagnostics. Modeling these cells involves addressing uncertainties in operational conditions, material properties, and design features. Additionally, uncertainties in experimental data, model selection, parameters, and model inadequacies must be carefully considered during PEMEC modeling. While uncertainty quantification (UQ) and sensitivity analysis (SA) can unveil how uncertainties propagate from input parameters to the output of PEMEC models, UQ has not been extensively integrated into PEMEC modeling. Finally, this presentation underscores the potential benefits of physics-based modeling combined with UQ and SA for PEM electrolysis [3].

Acknowledgment:

Financial support was provided by the German Federal Ministry of Education and Research (BMBF) within the H2Giga project DERIEL (grant number 03HY122C).

Literature:

[1] P. Trinke, 2021.
[2] P. A. García-Salaberri, J. Power Sources, 2022, 521.
[3] V. Karyofylli, Y. Danner, K. Ashoke Raman, H. Kungl, A. Karl, E. Jodat, R.-A. Eichel, J. Power Sources, 2024, 600, 234209.
Influence of Electrolyte Supply Scheme in Anion Exchange Membrane Water Electrolysis
Authors: Ito Hiroshi , Kageyama Akane , Ohtsuka Shyota , Ishida Masayoshi , Tateno Hiroyuki 
Published: December 2024

Recently, anion exchange membrane water electrolyzers have been attracting attention as a low-cost, high-performance water electrolysis system. In AEM water electrolysis, although water as fuel is consumed at the cathode, “cathode dry operation”, in which electrolyte solution is supplied only to the anode, can be applied. This operation scheme enables relatively dry hydrogen to be extracted from the cathode and has the advantages of simplifying the hydrogen purification line and facilitating pressurized operation. However, our previous study [1] has shown that cathode dry operation also has the problem of significant mass transfer overpotential due to water transport through the membrane.
In this study, both the bilateral electrolyte supply operation, in which the electrolyte solution is also supplied to the cathode, and the cathode dry operation were applied to the same cell, and the effects of the electrolyte supply scheme on the electrolysis performance were compared and examined.
Acknowledgement
This work was supported partly by the New Energy and Industrial Development Organization (NEDO) through the Advancement of Hydrogen Technologies and Utilization Project (P 14021). The authors wish to express their gratitude to Tokuyama Corporation for their support and helpful advice.
Reference
[1] R. Wang et al., Int. J. Hydrog. Energy, 47, 40835 (2022).
Time and Potential-Resolved Studies of Porous Transport Layers for PEM Water Electrolyzers Using on-Line ICP-MS
Authors: Dang Ngoc K , Kariuki Nancy N. , Myers Deborah J. 
Published: December 2024

Proton exchange membrane water electrolysis (PEMWE) is considered a promising technology for widespread hydrogen production from renewable energy sources due to its high efficiency, ability to rapidly respond to changes in variable electricity input, the high purity of the hydrogen produced, and many other advantages. One of the key components of PEMWE cells is the porous transport layer (PTL), which facilitates water transport to and oxygen removal from the anode catalyst layer. The properties of the PTL, such as thickness, porosity, composition and permeability, significantly affect the performance and efficiency of PEMWEs. Titanium is the state-of-the-art material for PTL. In spite of its high corrosion resistance, Ti-PTL on the anode tends to grow a thick oxide layer at the high potentials of the PEMWE anode. The resulting high interfacial contact resistance between the PTL and the catalyst layer leads to a decrease in the overall efficiency of the electrolysis process.1 Coating Ti parts with precious metals such as platinum (Pt) or iridium (Ir) is often used to protect against oxidation. 2,3 Our focus in this work is to study corrosion degradation of the anode Ti-PTL with and without coatings, as well as the corrosion of the coatings.
Inductively coupled plasma mass spectrometry (ICP-MS) connected on-line to an electrochemical flow cell (EFC) provides a highly sensitive technique to analyze the dissolution elements at trace levels (<ppb) under variable experimental conditions. This work will report the impact of several parameters, such as applied potential, potentiodynamic profile characteristics (e.g., hold time, scan rate, upper and lower potential limits), and temperature on the corrosion processes of Ti-PTL with and without coatings and of the Pt and Ir coatings. The corrosion rate data will be used to model degradation mechanism of PTL coatings towards mitigating degradation of PEMWE systems.

References

Prestat. J. Power Sources 2023, 556, 232469.

Liu, M. Carmo, G. Bender, A. Everwand, T. Lickert, J.L. Young, T. Smolinka, D. Stolten, W. Lehnert. Electrochemistry Communications 2018, 97, 96.

S. Gago, S.A. Ansar, B. Saruhan, U. Schulz, P. Lettenmeier, N.A. Cañas, P. Gazdzicki, T. Morawietz, R. Hiesgen, J. Arnold, K.A. Friedrich. J. Power Sources 2016, 307,815.

Acknowledgements

This research is supported by the U.S. Department of Energy, Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office under the auspices of the H2NEW consortium. Argonne National Laboratory is managed for the U.S Department of Energy by the University of Chicago Argonne, LLC under contract DE-AC-02-06CH11357.
Technoeconomic Analysis and Comparison of PBI-Based Aqueous and Anhydrous HCl Electrolysis Processes
Authors: Felix Olusegun Odunayo , Shimpalee Sirivatch , Meekins Benjamin 
Published: December 2024

In this talk, we develop full electrolysis processes, including balance of plant equipment, and compare the economics and production of both a state-of-the-art aqueous HCl electrolyzer and fully anhydrous HCl electrolyzer. We demonstrated recently that a PBI membrane enables the direct electrolysis of anhydrous HCl1,2 , producing separated and high purity hydrogen and chlorine product streams. Development of this process from lab-scale to industrial-scale, however, requires consideration of not just the electrolyzer itself, but also the pre- and post-electrolyzer equipment needed to handle the inlet and outlet material streams. It is also important to compare any newly proposed or demonstrated process to the current state-of-the-art to better understand where the new process either excels or falls short.
Our approach involved developing a full electrolyzer model in Aspen Custom Modeler (ACM), facilitating the comparison of parameters such as single-pass conversion of HCl and current densities across various operating conditions. Notably, this model permits the optimization of operating parameters without presuming fixed conversions, distinguishing it from most models employing Aspen Plus. We also aim to validate this model against our experimental results to assess its accuracy. Furthermore, we conduct a detailed techno-economic analysis of the pre- and post-electrolyzer units, followed by the optimization of post-processing unit operations. Our objective is to identify the most cost-effective and sustainable means of production.
We will show that while the anhydrous electrolyzer, taken alone, requires more input power than its aqueous counterpart, the full anhydrous electrolysis process is both cheaper to build and operate and uses less energy overall. We consider the impact of hydrogen production on the economics of the anhydrous process, and we show how operating the anhydrous electrolyzer at different conversion efficiencies impacts the overall production rate and operating cost. Finally, we will note potential improvements in the anhydrous electrolysis process by identifying equipment that represent major impacts on energy and financial costs.

K. Likit-anurak et al., International Journal of Hydrogen Energy, 47, 26859–26864 (2022).

K. Likit-anurak et al., ACS Appl. Energy Mater., 6, 5429–5434 (2023).
Engineering the Diaphragm to Minimize Gas Crossover in Alkaline Water Electrolysis
Authors: Gellrich Florian , Kraglund Mikkel Rykær , Jensen Jens Oluf , Stiesdal Henrik 
Published: December 2024

Hydrogen, a versatile energy carrier, is essential for the transition to renewable energy systems. Electrolytically produced hydrogen using renewable sources is a core technology for decarbonizing industries and societies. However, at the end of 2021, electrolysis contributed only about 4% of global hydrogen production [1].
Various electrolytic hydrogen production techniques exist, including Proton Exchange Membrane Electrolysis (PEMEC), Solid Oxide Electrolysis (SOEC), Anion Exchange Membrane Electrolysis (AEMEC), and liquid Alkaline Water Electrolysis (AEL) [2]. AEL is the most mature and scalable technology, and it doesn't require precious metals. However, for efficiencies comparable to other techniques, AEL typically operates at low current densities of 0.2-0.5 A/cm2 (100% of rated current density). A porous diaphragm separates the produced hydrogen and oxygen in AEL.
A key limitation to part-load operation of electrolyzers is hydrogen crossover into the oxygen stream, posing a safety hazard at concentrations exceeding 4%. Diffusion of dissolved gases through the diaphragm is the main crossover mechanism in balanced AEL systems and depends on electrolyte concentration and supersaturation [3]. Therefore, addressing supersaturation can significantly enhance AEL operational flexibility [4]. While crossover is marginally affected by current density, the 2% hydrogen-in-oxygen safety limit necessitates AEL shutdown at roughly 25% of rated current density to prevent hazardous mixtures.
Stiesdal Hydrogen is a climate change company developing next-generation Alkaline Water Electrolysis systems. Our hydrogen electrolyzers operate within a pressure tank, eliminating the need for a hydrogen compressor and enabling direct production at up to 35 bar. To achieve operational flexibility below 25% of rated current density without sacrificing efficiency, we have engineered a novel diaphragm with a pore structure optimized to mitigate gas crossover.
[1] IRENA Hydrogen Overview https://www.irena.org/Energy-Transition/Technology/Hydrogen downloaded on 17/04 2024 08:00 MET
[2] J. Hnát et al 2020 New Perspectives on Hydrogen Production, Separation, and Utilization 91-117
[3] P. Trinke et al 2018 J. Electrochem. Soc.
165 F502
[4] M. T. de Groot et al 2022 Int. J. Hydrogen Energy
47 82
Flow-Field Designs for PEM Water Electrolysis Cells: Performance and Contact Behavior
Authors: Weiland Oskar , Stein Lukas , Venkatesan Prasad , Trinke Patrick , Bensmann Boris , Hickmann Thorsten , Hanke-Rauschenbach Richard 
Published: December 2024

Introduction

This study examines the influences of flow field designs on Proton Exchange Membrane (PEM) water electrolysis cells. The flow field structure has an impact on fluid and heat distribution which in turn influences the performance locally [1]. In addition, different designs affect the mechanical compression through the layers. This can lead to unfavourable contacting between the layers, which also affect the cell performance.

Methods

Ten different flow field designs are tested in a 4 cm2 single cell setup. The designs include a variation of parallel channel and rib widths and distances (Fig 1.a), a serpentine channel arrangement (Fig 1.b), planar geometries without connecting channels (Fig 1.c) and block geometries (Fig 1.d). Polarisation curves and high frequency resistance (HFR) are measured and Tafel analysis are done to evaluate the performance. Residual overpotentials including mass transport are extracted. Additionally, pressure measuring films are used to qualitatively measure the mechanical pressure distribution in the membrane-electrode assembly (MEA).

Results

The HFR of the different designs differs by up to 32 %. This is the main driver in the polarisation curve differences shown in Fig. 2. However, it appears that the flow field structure (channel width, channel position) and contact area between end-plate and PTL is strongly affecting the interface of the porous transport layer (PTL) and the MEA in a multiple manner. A poorly designed flow field leads to electrochemically inactive MEA areas, whereas optimal designs benefit from a homogenous mechanical pressure distribution for optimal contact between PTL and MEA. This also influences the residual overpotential in different ways.

References

[1] A. C. Olesen, S. H. Frensch and S. K. Kær, Electrochimica Acta,
293, 476–495 (2019).
The authors gratefully acknowledge funding by BMWK (German Federal Ministry of Economic Affairs and Climate Action) in the framework of the project TICOB (FKZ 03EI3048B).

Figure 1
Baselining Unitized Reversible Fuel Cells with Low Catalyst Loadings: Performance and Durability Insights
Authors: Li Yuanchao , Arman Tanvir Alam , Komini Babu Siddharth , Spendelow Jacob S. 
Published: December 2024

Unitized Reversible Fuel Cells (URFCs) combines the functionality of hydrogen fuel cells and water electrolyzers into a single device, offering high energy density for energy conversion and storage. However, their commercial viability is deterred by the high precious group metal (PGM) loadings. Conventional URFCs utilize 1 mg/cm2 of Pt and 1 mg/cm2 of IrO2 in the oxygen electrode, posing economic and sustainability challenges.
This study investigates the performance and durability implications of minimizing PGM loadings in oxygen electrode which utilizes a mixture of IrO2 and Pt black to facilitate oxygen evolution and oxygen reduction reaction respectively. We also examine the effect of the porous transport layer (PTL) morphology and wettability on the URFC performance and durability. Accelerated stress test (AST) protocol was developed to evaluate the performance loss across both fuel cell and water electrolyzer mode of URFC operation. Additionally, this research provides a detailed characterization of loss in active area, change in catalyst layer structural, and PTL wettability offering insights into the degradation mechanism in URFCs.
This study not only establishes a foundational benchmark for understanding the URFC performance and durability at low catalyst loadings but also highlights the critical need for strategic component selection and activation methods to enhance the system's overall efficiency and durability, marking a significant step towards the realization of more sustainable energy solutions.