bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluating the Impact of Cell Assembly and Operating Conditions on the Performance of Anion Exchange Membrane Electrolyzers
Authors: Amirsalehi Mahmoud , Gopi K Hari , Satjaritanun Pongsarun , Moreno Marta , Britton Benjamin , Mustain William Earl 
Published: August 2024

The alkaline water electrolyzer (AWE) and proton exchange membrane water electrolyzer (PEMWE) are the two dominant commercial platforms to produce hydrogen through electrolysis. Recent efforts have focused on combining the benefits of the two technologies, leading to the creation of the anion exchange membrane water electrolyzer (AEMWE). AEMWEs operate under high pH conditions, like AWEs, enabling the use of cost-effective materials as cell components and non-noble electrocatalysts. AEMWEs also utilize the same high-performance zero-gap design PEMWEs and also have the ability to operate at high differential pressures. Therefore, AEMWEs offer the opportunity to optimize both cost and performance, out-pacing both incumbent technologies after further development.
As the “active” materials in AEMWEs, the anion exchange membranes and ionomers and the catalysts have been widely studied and a number of materials have been proposed and reported on in the literature and throughout the last several ECS meetings. However, such materials are only one piece of the overall puzzle when it comes to the operation of AEMWEs. There are several aspects of cell assembly and operation that go a long way to dictating the performance of an operating cell.
Therefore, the overarching goal of this study was to investigate several operational variables for AEMWEs with a known high-quality set of anion-exchange materials, known commercially as Aemion+™ paired with commercially available catalysts – PtNi/C at the cathode and either IrOx or NiFeOx at the anode. For cell assembly, representative variables that were changed were the type of membrane and electrode pre-treatment, gasket thickness, cell torque and membrane thickness. Operationally, temperature, current density and break-in procedure were adjusted. This talk will link each of these variables to the polarization performance and galvanostatic durability
Investigating Water and Ion Transport in a Novel Cell Design for Seawater Electrolysis
Authors: Al Murisi Mohammed , Ghasemi Masoomeh , Ali Rashad , Yang Xiaoxuan , Bimbatti Yasmin , McCutcheon Jeffrey , Kohl Paul , Shimpalee Sirivatch , Mustain William Earl 
Published: August 2024

With increasing concerns about the climate change associated with the carbon dioxide emission from utilizing traditional fuels, hydrogen has become a preferred low-carbon energy carrier. For hydrogen to truly be a clean source of energy, it must be produced from a renewable source of energy through water electrolysis. Theoretically, for each kilogram of hydrogen to be produced 9 kg of high-purity water need to be consumed, thus the enormous use of clean water for H2 production may worsen the shortage of fresh water in many parts of the world.
Owing to its abundance, seawater has received great attention in the field of hydrogen production; however, there are many challenges associated with the direct use of seawater for electrolysis. In traditional systems, the seawater is first deionized by reverse osmosis (RO) before being fed to the electrolyzer. The RO system adds complexity to the system and requires energy to be expended for the deionization. Therefore, modern systems have aimed to directly electrolyze seawater, but this comes with it own issues including electrode corrosion, scaling from the ions present in saline water, environmental concerns associated with competitive chlorine evolution reaction, and increased membrane resistance limiting the overall performance of saline water electrolysis. Several strategies have been proposed to overcome these challenges including developing selective electrocatalysts, blocking strategy, pH buffer strategy, etc.
This project sought to overcome the issues with direct seawater utilization by designing a cell that is driven by osmotic separation, but does not require an external power source. In this device, high concentration acid/base concentrations are maintained in contact with another compartment containing seawater. The acid/base reservoirs act as draw solutions, taking water passively from seawater due to their differences in osmotic pressure. This talk will focus on the cell design and operation, and include both experimental and modeling results. The rate of water transport with various cell operating configurations was quantified alongside the rate of chloride ion crossover through the anion exchange membrane. New methods for chloride mitigation were explored – including cell operating conditions, membrane design and absorption. Multiple cell configurations will be shown and strategies for reducing the cell operating voltage will be discussed.
(Invited) Comparison of Catalyst-Coated Electrodes vs. Catalyst-Coated Membranes in PEM Water Electrolysis Cells
Authors: Millet Pierre , Al Cheikh Joumada , Albacha Serge , Abdel Motagali Ali , El Rouby Waleed 
Published: August 2024

The PEM (Proton-Exchange Membrane or Polymer Electrolyte Membrane) cell concept [1] is used in fuel cells and water electrolysis cells. PEM water electrolysis is a compact, efficient and flexible technology for the production of “green-hydrogen” from renewable (intermittent) energy sources. The unit cell (Figure 1) is made of several adjacent functional layers: (i) the proton-conducting polymer membrane (1); (ii) two catalysts layers (CLs) for hydrogen/oxygen evolution containing platinum group metals or PGMs (2;2’); (iii) a porous transport layer used for mass transport of reactants/products and electricity distribution (3;3’); (iv) water flow fields for water circulation (4;4’); bipolar plates (5;5’). From a practical viewpoint, the CLs can be deposited on either side of the interfaces formed between the polymer membrane and the porous transport layer: (i) on the supporting porous transport layers to form catalyst-coated electrodes which are then hot pressed against the bare membrane to form membrane – electrode assemblies; (ii) directly onto the membrane to form catalyst-coated membranes (CCM).
The aim of this paper is to evaluate the efficiency and durability of both concepts, drawing on recent advances in manufacturing techniques to reduce the loading of PGM catalysts.
[1] W.T. Grubb Jr., Batteries with Solid Ion-Exchange Electrolytes. Journal of the Electrochemical Society. 106 (1959) 275-279.
[2] C. Rozain, P. Millet, Electrochemical characterization of Polymer Electrolyte Membrane Water Electrolysis Cells, Electrochimica Acta, 131 (2014) 160-167.

Figure 1. Schematic diagram showing the cross-section of a PEM water electrolysis cell [2].

Figure 1
The Effect of PTFE Dip Coating on Enhancing the Durability and Performance of Anion Exchange Membrane Electrolyzers
Authors: Al Murisi Mohammed , Ganesan Prabhu , Mercado Hector-Colon , Mustain William Earl 
Published: August 2024

Anion exchange membrane electrolyzers (AEMELs) are widely regarded as one of the most promising technologies to enable low-carbon hydrogen production. AEMELs can combine the advantages the traditional alkaline electrolyzer (AEL) and proton exchange membrane electrolyzer (PEMEL) – allowing for the use of PGM free electrodes, high operating current density, environmentally friendly materials, and compact design. Although significant progress has been made in the field of AEMELs, there is still a gap in performance compared to PEMELs that can be overcome through electrode design.
One of the most critical aspects affecting the overall performance of the AEMEC is the water management. It has a major influence on cell behavior, and specifically mass transfer at the anode side of the cell. To improve AEMEL anode water dynamics, our team modified its porous transport layer (PTLs) through the addition of controlled amounts of hydrophobic polytetrafluoroethylene (PTFE). This study investigated the effect of PTFE loading and coating method on the performance of AEMELs. Ni-based PTLs were used. Experimental results revealed that a low amount of PTFE not only enhanced the performance, but it also enhanced the catalyst layer attachment. On the other hand, higher PTFE content led to a reduction in water availability in the electrode, leading to increased mass transfer overpotentials. In summary, increasing the hydrophobicity of Ni-PTLs appears to improve AEMEC performance, with the best performing electrodes having a PTFE loading of ~1-2% (equivalent to 5-10 wt.% on carbon GDLs).
Towards High-Performance AEM Water Electrolyzers: Transitioning from PGM to Low-PGM and PGM-Free Electrocatalysts
Authors: Amirsalehi Mahmoud , Ul Hassan Noor , Gopi K Hari , Mustain William Earl 
Published: August 2024

Hydrogen, known for its high gravimetric energy density and low environmental impact, is widely regarded as a promising low-carbon energy carrier. The production of hydrogen via water electrolysis offers a valuable opportunity to efficiently utilize renewable energy resources – both as a storage and transport medium and to produce hydrogen that is a crucial feedstock for multiple industrial and manufacturing applications. Among various water electrolysis technologies, anion exchange membrane water electrolyzers (AEMWEs) are notable for their distinct and advantageous features. Their alkaline operational environment significantly reduces corrosion, allow for the possibility to use catalysts and cell component materials that are earth abundant and cost effective. Moreover, the use of anion exchange membranes (AEMs) as the electrolyte and zero-gap design enhance operational efficiency and hydrogen production rates compared to traditional alkaline electrolyzers. These benefits position AEMWEs as a compelling solution for efficient, cost-effective large-scale hydrogen production.
To date, the development of lower-cost AEMWEs has been hindered by several challenges. A critical issue is the activity and durability of catalysts, particularly those that are platinum group metal (PGM)-free. This leads many researchers and electrolyzer manufacturers to lean on PGM catalysts at both the anode and cathode. These catalysts, while effective, significantly increase the cost and complexity of the system, posing a barrier to widespread adoption and commercialization of AEMEL technology in the burgeoning hydrogen economy. PGM-free anodes have been demonstrated for the AEMWE, but there have been fewer PGM-free options for the cathode.
This study assessed the performance and durability of various low-PGM and PGM-free electrocatalysts for the oxygen evolution (OER) and hydrogen evolution (HER) reactions. We focused on Lanthanum Strontium Cobalt (LSC), Nickel Ferrite (NiFeOx), and Lead Ruthenate (PbRuOx) for the OER at the anode, and Nickel Molybdenum (NiMo), Nickel Rhenium (NiRe), and a low-PGM PtNi for the HER at the cathode. Furthermore, the performance of the NiMo HER catalyst was enhanced by optimizing the physical properties of both the catalyst powder and the electrodes. These experimental results offer crucial insights into developing PGM-free AEM water electrolyzer systems, marking a progressive step towards their commercial feasibility.
Earth-Abundant Metal Oxides as Oxygen Evolution Electrocatalysts in 1 M H2SO4
Authors: Yu Jiahao , Garcés Pineda Felipe , Galan-Mascaros Jose Ramon 
Published: August 2024

Water splitting is a very hot research topic as a preferred source for green hydrogen, as a key vector to facilitate a transition into an environmentally friendly and sustainable energy economy in the mid-term. But it is still far from being economically competitive with respect to current hydrogen production technologies based on fossil fuels. One of the major economic hurdles to reduce electrolysis costs is the lack of low-cost catalysts for hydrogen evolution and, more importantly, for oxygen evolution. The water oxidation process is considered the main bottleneck in the advancement of water splitting devices, since it is the rate limiting process, and the main cause of poor long-term performance.
Most recent advances in the field of water oxidation catalysis are based on transition metal oxides, operating exclusively in alkaline electrolysis conditions. Unfortunately, these excellent oxygen evolution catalysts in basic pH ( > 13) rapidly lose their activity when the pH is lowered, and are far away from the performance exhibited by noble metals in acid solution. McCrory et al. established in 2013
1a benchmarking protocol to identify the potential of new OER electrocatalysts (and extended in 2015
2 to HER) comparing the initial activity and stability of the materials as a function of pH and showed how no other known catalysts at that time came close to the performance of IrOx-based materials.
A simple processing technique using a partially hydrophobic binder has been proved to stabilize Co oxide, resulting in electrodes able to reach high current densities (> 10 mA cm-2) at competitive overpotentials and with long term stability for acidic OER catalysis3. Following this strategy, we have been able to conduct an extensive survey of the activity and stability of monometallic, binary and ternary earth-abundant transition metal oxides during electrocatalytic OER in 1 M H2SO4. Our results confirm the general validity of the strategy in using a partially hydrophobic electrode to confer high stability to common metal oxides under these harsh conditions.
[1] C.C.L. McCrory, S. Jung, J.C. Peters, T.F. Jaramillo, Benchmarking heterogeneous electrocatalysts for the oxygen evolution reaction, J. Am. Chem. Soc. 135 (2013) 16977–16987.
[2] C.C.L. McCrory, S. Jung, I.M. Ferrer, S.M. Chatman, J.C. Peters, T.F. Jaramillo, Benchmarking Hydrogen Evolving Reaction and Oxygen Evolving Reaction Electrocatalysts for Solar Water Splitting Devices, J. Am. Chem. Soc. 137 (2015) 4347–4357.
[3] J. Yu, F.A. Garcés-Pineda, J. González-Cobos, M. Peña-Díaz, C. Rogero, S. Giménez, M.C. Spadaro, J. Arbiol, S. Barja, J.R. Galán-Mascarós, Sustainable oxygen evolution electrocatalysis in aqueous 1 M H2SO4 with earth abundant nanostructured Co3O4, Nat. Commun. 13 (2022) 4341.

Figure 1
Durability and Performance of Poly(norbornene) Anion Exchange Membrane Alkaline Electrolyzer with High Ionic Strength Anolyte
Authors: Park Habin , Li Chenyu , Kohl Paul 
Published: August 2024

Anion exchange polymer electrolytes enable low-temperature alkaline water electrolysis for reliable green hydrogen production. Anion exchange membrane water electrolysis (AEMWE) with alkaline electrolytes has several advantages over the proton exchange membrane water electrolysis using acid-based polymer electrolytes. The advantages include low-cost catalysts, all hydrocarbon non-fluorinated polymer membrane, and low-cost cell components. Long-term durability of AEMWEs in high pH operation has been challenging, although there have been significant performance improvements. AEMWE operated at low hydroxide anolyte provides improved chemical stability.
In this study, an understanding of the high ionic-strength anolyte is provided along with demonstration of the AEMWE performance and durability. Anion exchange poly(norbornene) solid polymer electrolytes show high-performance, durable membrane electrode assemblies for alkaline electrolysis. Covalently bonded, self-adhesive solid polymer ionomers were used in electrodes for durable electrolysis. Hydration problem with the low pH alkaline anolyte in dry-cathode AEMWE is presented. The effect of anolyte concentration and mobile cations on the cathode electrolysis performance using a low hydroxide anolyte was investigated. High ionic strength anolyte was prepared by changing the mobile cation concentration while maintaining a constant anolyte pH. The mechanism of cathode hydration improvement through use of a high ionic strength anolyte is presented. Long-term durability with the optimal high ionic strength electrolyte is discussed.
Microwave Synthesis of New Co-Polypyrrole-Polyketone Anion Exchange Membranes
Authors: Lanero Francesco , Crivellaro Giovanni , Nale Angeloclaudio , Vezzù Keti , Di Noto Vito , Sgarbossa Paolo 
Published: August 2024

Polyketones can be easily converted in a series of new polymeric anion exchange membranes (AEMs) with a stable polypyrrole-polyketone backbone structure from which the ion exchange side-groups stem [1-3]. Here we present our findings on the functionalization with two different cycloaliphatic primary amines of a commercial and inexpensive terpolymer polyketone (PK) through the Paal-Knorr chemistry. We also studied the possibility to drastically reduce the reaction time by investigating alternative and greener heating sources such as microwave heating. The molecular structure, thermal and conductive properties of the membranes were studied in order to shed light on and compare the effect of the different heating methods on the materials behavior [4], and to lead the way to their further optimization for the possible application in electrochemical devices. The obtained membranes showed a promising anion conductivity in the hydroxide form, up to 10mScm-1, and an exceptional thermal stability, about 250°C.
[1] G.Nawn, K.Vezzù, G.Cavinato, G.Pace, F.Bertasi, G.Pagot, E.Negro, V. Di Noto, Adv. Funct. Mater. 2018, 1706522
[2] N.Ataollahi, F.Girardi, E.Cappelletto, K.Vezzù, V.Di Noto, P.Scardi, E.Callone, R.Di Maggio. Journal of Applied Polymer Science. 2017, 134, 45485.
[3] A.R.Alvi, K.Vezzù, , G.Pagot, P.Sgarbossa, G.Pace, V.Di Noto, Macromolecular Chemistry & Physics. 2022, 223, 2100409.
[4] S.Bonizzoni, D.Stucchi, T.Caielli, E.Sediva, M.Mauri, P.Mustarelli, ChemElectroChem. 2023, e202201077.

Figure 1
Understanding How Porous Transport Layer Features Affect Proton Exchange Membrane Electrolyzer Performance
Authors: Hasa Bjorn , Zhu Gaohua , Aryal Utsav Raj 
Published: August 2024

PEM Water electrolysis has emerged as a promising technology for the production of green hydrogen. A key component of PEM electrolyzer is the porous transport layer (PTL). The porous transport layer has numerous important roles in water electrolysis. In addition to enabling electrical conduction and water and gas transport, the PTL is necessary for maintaining excellent contact with the cell components. Cell performance is anticipated to be affected by PTL properties such as structure, composition, and thickness.
This study delves into the critical contribution of porous transport layer properties to mass transport resistance, activation losses, catalyst layer resistance, and ohmic losses. I will present our experimental framework to deconvolute the impact of PTL properties such as thickness, porosity, and microporous layer on various overpotentials. Voltage loss breakdown analysis was conducted to determine kinetic, ohmic, mass transport, and catalyst layer losses. Theoretical calculations of thermodynamic voltage typically rely on standard reaction potentials adjusted for reactant and product concentrations, operating temperature, and pressure via Nernst corrections. Ohmic voltage, which accounts for contact resistances, bulk resistances, and ohmic losses from the membrane, was determined using high-frequency impedance spectroscopy measurements. To calculate losses from OER kinetics, a Tafel fit is subsequently implemented on the HFR-free voltage. Typically, this process tends to result in residual voltage at elevated current densities, including losses arising from mass transport of water and oxygen, resistance within the catalyst layer, and impacts stemming from ionic impurities. Ionic contamination is omitted from our analysis as a result of the short duration of the experiment.
Our detailed analysis reveals that the properties of PTL can have a substantial impact on the performance of the water electrolyzer, which is crucial for enhancing the performance and durability of PEMWE. This study presents a novel framework for forecasting the performance of diverse PTL materials, which may be effectively used to drive the development and optimization of PTL for water electrolyzers.

Figure 1
Performance Optimization of Alkaline Water Electrolysis Via Catalyst Morphology Tuning and Novel Cell Design
Authors: Li Chenzhao , Stracensky Thomas , Slenker Benjamin , Gupta Ankur , Yang Zhiwei (Jv) , Xu Hui 
Published: August 2024

Hydrogen is a basic energy carrier for numerous valuable industrial products. Green hydrogen produced using renewable electricity and water electrolysis is pivotal in advancing a decarbonized sustainable energy ecosystem. Two primary electrolysis technologies, alkaline water electrolysis (AWE) and polymer electrolyte membrane water electrolysis (PEMWE), have demonstrated a viable commercial perspective. AWE is particularly well-suited for large-scale deployment, especially at the gigawatt scale, due to low capital cost and long lifetime. [1]. The performance of AWE is largely determined by the effectiveness of nickel-based oxygen evolution reaction (OER) catalysts and PGM-based or PGM-free hydrogen evolution reaction (HER) catalysts. To enhance the catalyst activity and cell performance, we meticulously control morphology and chemical composition of the catalysts. Cell testing was conducted in cells of various active areas (5, 25, and 50cm2) to demonstrate the result consistency and scalability. An innovative cell design, incorporating a reference hydrogen electrode in both cathode and anode, enabled the real-time acquisition of half-cell polarization curves during tests. This configuration proved valuable information to identify performance limitations in the single cells, thus guiding effective cell design and optimization. Furthermore, a cell comprising Ni-based anode and PGM cathode demonstrated remarkable stability.
1. Schalenbach, Aleksandar R. Zeradjanin, Olga Kasian, Serhiy Cherevko, and Karl J.J. Mayrhofer, Int. J. Electrochem. Sci., 1173–1226 (2018).
Effect of Electrolytes on Performance of Tire Derived Carbon for Sodium-Ion Batteries
Authors: Paranthaman M. Parans , Pethe Saurabh Prakash , Sun Xiao-Guang 
Published: August 2024

Sodium-ion batteries (SIBs) have recently become prominent in the battery ecosystem due to their low cost and use of earth abundant materials such as Sodium, Manganese, Aluminum, Iron, and Prussian blue (iron cyanide). [1] Graphite is the standard anode used for LIBs but cannot be used in SIBs due to interlayer distance being too small to accommodate Na+ ion. Hard carbons are suitable candidates for SIB due to their low cost, low working potential, high capacity, and ability to be synthesized at lower pyrolysis temperatures. In our past work we have reported a low-cost, scalable waste tire-derived carbon as an anode for SIBs [2]. In this work we test the tire derived carbon with 6 different electrolytes and understand the impact each has on the performance. The best electrolyte was found to be sodium hexafluorophosphate in ethylene carbonate (EC)–ethyl methyl carbonate (EMC) (NaPF6-EC/EMC) which showed a capacity of 108 mAh/g after 200 cycles at charge/discharge rate of C/3. The initial columbic efficiency (ICE) was found to be 52% and to mitigate this problem we tried a scalable contact pre-sodiation method. The pre-sodiation method showed high initial columbic efficiency drastically improving capacity retention of the battery.

References

1. Li, F., et al., Sodium-based batteries: from critical materials to battery systems. Journal of materials
chemistry A, 2019. 7(16): p. 9406-9431.
2. Li, Y., Paranthaman, M.P., Akato, K., Naskar, A.K., Levine, A.M., Lee, R.J., Kim, S.O., Zhang, J.,
Dai, S. and Manthiram, A., 2016. Tire-derived carbon composite anodes for sodium-ion
batteries. Journal of Power Sources, 316, pp.232-238.