bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Catalyst Challenges for Ion-Pair High Temperature Proton Exchange Membrane Fuel Cells
Authors: Lim Katie Heeyum , Maurya Sandip , Hu Zhendong , Jia Hongfei , Matanovic Ivana , Zulevi Barr , De Castro Emory Sayre , Fujimoto Cy , Kim Yu Seung 
Published: November 2022

High temperature proton exchange membrane fuel cells (HT-PEMFCs) have several merits over low temperature PEMFCs, including simplified fuel cell systems and high CO tolerance. Recently developed ion-pair HT-PEMFCs1 has a significantly lower concentration of phosphoric acids in the membrane-electrode assembly (MEA) that allows ion-conducting binders (ionomers) in the electrodes. Here, we first explain the difference in MEA configurations and fuel cell performance between conventional polybenzimidazole-based and ion-pair HT-PEMFCs2. Next, we discuss catalyst challenges for ion-pair HT-PEMFCs by comparing half-cell and single-cell results.
We focus on three critical areas in that electrocatalysts face challenges: i) phosphate anion poisoning on oxygen reduction reaction catalysts, ii) phenyl adsorption on hydrogen oxidation reaction catalysts and iii) phosphoric acid flooding. Research progress mitigating those adverse effects is demonstrated using various commercial Pt-based catalysts and homemade ionomers. Lastly, we provide general directions for designing high-performing catalysts of ion-pair HT-PEMFCs.
References

Lee, K. S.; Spendelow, J. S.; Choe, Y. K. Fujimoto, C.; Kim, Y. S. An Operationally Flexible Fuel Cell Based on Quaternary Ammonium-Biphosphate Ion Pairs, Nature Energy, 1, 16120 (2016).

Lim, K. H.; Lee, A. S.; Atanasov, V.; Kerres, J.; Park, E. J.; Adhikari, S.; Maurya, S.; Manriquez, L. D.; Jung, J.; Fujimoto, C.; Matanovic, I.; Jankovic, J.; Hu, Z.; Jia, H.; Kim, Y. S. Protonated phosphonic acid electrodes for high power heavy-duty vehicle fuel cells, Nature Energy, 7, 248 (2022).
High Performance AEM Water Electrolysis with PGM-Free Electrocatalysts
Authors: Ul Hassan Noor , Shakouri Abolfazl , Adabi Firouzjaie Horie , Duanghathaipornsuk Surachet , Zulevi Barr , Kohl Paul , Mustain William Earl 
Published: November 2022

Water electrolysis technologies for hydrogen production are getting much attention due to drastic cost reduction in renewable energy sources, like solar, wind, tidal etc. Traditional alkaline water electrolysis has limitations of low current density operation, slow system response and low hydrogen discharge pressure. Proton exchange membrane (PEM) water electrolysis offers compact design, high current density operation, fast system response and pressurized discharge hydrogen. However, PEM electrolyzers require the use of Platinum Group Metal (PGM) based electrocatalysts, expensive perfluorinated membranes and specialized component materials due to its acidic environment. These are all hurdles to its widespread commercial adoption. A relatively new technology, the anion exchange membrane (AEM) electrolyzer can potentially combine benefits from PEM and traditional alkaline electrolyzers, offering high current density operation, pressurized discharge gas and low cost – by utilizing PGM-free electrocatalysts and inexpensive component materials due to the less corrosive alkaline operating environment.
However, modern AEM electrolyzers have continued to use high loadings of PGM catalysts in both the cathode and anode. Given the magnitude and recent volatility in the market price of many PGM-group metal catalysts (e.g. Ru, Ir, etc.), it is now even more important for AEM electrolyzers to be realized with significantly lower PGM content – and eventually approaching the complete elimination of PGMs.
In this study, we evaluate the performance of several low-PGM and PGM-free electrocatalysts for the oxygen evolution (OER) and hydrogen evolution (HER) reactions for high performance and durability. Here, PGM-free Lanthanum Strontium Cobalt (LSC), Nickel Ferrite (NiFeOx) and low PGM Lead Ruthenate (PbRuOx) were used at the anode for the OER. For the HER cathode, PGM-free Nickel Molybdenum (NiMo) and low-PGM PtNi electrocatalysts were evaluated for their in-situ activity and durability. It will be shown that LSC and NiFeOx show comparable performance to IrOx, with a typical steady-state operating voltage at 60oC and 1.0 A/cm2 (with 0.3 M KOH fed to the anode only) below 1.80 V. Cells with PGM-free anode catalysts were operated stably for over 100 hours. At the cathode, NiMo showed relatively higher overpotentials compared to Pt black, PtNi or Pt/C for the HER. Because of this, various strategies were adopted to reduce the PGM loading while achieving high performance and durable AEM electrolyzer operation. The achieved experimental results provide important insights for the development of AEM based water electrolyzer systems and represent an active step towards its commercial viability.
Modeling Thermal Runaway of Large Format All-Solid-State Lithium Metal Cells during a Thermal Ramp Test and Short Circuit: Sensitivity Analysis and Reaction Pathways
Authors: Johnson Nathan B , Albertus Paul 
Published: November 2022

While high-energy batteries with an inorganic solid electrolyte may offer improved safety compared with current Li-ion cells because of the lack of a flammable liquid electrolyte, this is a topic that requires careful analysis. In our past work we modeled an LiyCoO2|LLZO|Li large format cell in a thermal ramp test and with a short circuit in a portion of the cell that led to thermal runaway of the entire cell.1 In the present talk we explore several key sensitivities and limitations in our large-format solid state cell model, those sensitivities include the specific energy, electrode capacity ratio, heat transfer to the surroundings, kinetic parameters for key exothermic reactions (e.g., Li2O formation), and others. Our previous modeling work also only considered the potential reaction of lithium metal with oxygen released from the cathode, as the differential scanning calorimetry (DSC) data on which our model was built did not include other cell reactions.2 In the present talk we also present results with an expanded kinetic model to include processes such as lithium/current collector alloying, oxidation of binder, oxidation of conductive carbon, and reaction of lithium with other gaseous products. The impact of modifying our baseline model parameters, and adding additional reactions, on the onset temperature for thermal runaway, the maximum heating rate, and the maximum temperature reached during thermal runaway.
References:
(1) Johnson, N. B.; Albertus, P. Modeling thermal behavior and safety of large format all-solid-state lithium metal batteries under thermal ramp and short circuit conditions. Submitted.
2022.

(2) Inoue, T.; Mukai, K. Are All-Solid-State Lithium-Ion Batteries Really Safe?−verification by Differential Scanning Calorimetry with an All-Inclusive Microcell. ACS Appl. Mater. Interfaces
2017, 9 (2), 1507–1515.
(Digital Presentation) Development of Bifunctional Oxygen Electrocatalysts for Electrically Rechargeable Zinc-Air Batteries
Authors: Mathialagan Kowsalya , T Saranya , Surendran Ammu , Dixon Ditty , S.T. Nishanthi , Bhaskar Aiswarya 
Published: November 2022

Zinc-air battery is a promising battery system as it possesses high theoretical energy density and is cost-effective3. The theoretical energy density of a Zinc-air battery is 1086 Wh kg-1, which is five times greater than that of lithium-ion batteries2. Moreover, zinc metal is one of the most abundant metals in the earth’s crust and is inexpensive. Rechargeable metal-air batteries operate based on two fundamental electrochemical reactions as Oxygen Reduction Reaction (ORR) during discharge and Oxygen Evolution Reaction (OER) during recharge processes, respectively3. Electrocatalytic activity of the bifunctional electrocatalyst towards these two oxygen reactions will decide the performance of the battery1. Recent advancements in catalyst development are the fabrication of rechargeable air electrodes using a single active material that is capable of bifunctionally catalyzing ORR and OER3. The development of bifunctional catalysts with high activity is necessary for rechargeable metal-air batteries, such as zinc-air batteries3.
In this work, a perovskite-type LaFeO3 material was synthesized using a citric acid-assisted sol-gel method and is investigated as bifunctional oxygen electrocatalyst for electrically rechargeable zinc-air batteries. Structural studies using X-ray diffraction revealed the formation of phase pure LaFeO3 in space group Pbnm. This catalyst displayed considerable bifunctional catalytic activity for both oxygen reduction (0.74 V vs. RHE) and oxygen evolution reactions (0.40 V vs. RHE at 10 mA cm-2) in 1 M KOH electrolyte. Electrically rechargeable zinc-air batteries assembled using LaFeO3 as the oxygen electrocatalyst deliver a specific capacity of 936.38 mAh g(
Zn)
-1 after the 1st discharge. Further details will be discussed in the poster.
Financial support from Department of Science and Technology, Govt. of India under research grant number DST/TMD/MECSP/2K17/20 is gratefully acknowledged.

References:

[01] Y. Li, M. Gong, et. al., Nature communications, 4, (2013), 1-7
[02] P. Gu, M. Zheng, et. al., Journal of Material Chemistry, (2017), 1-17
[03] D. U. Lee, P. Xu, et. al., Journal of Material Chemistry, 4, (2016), 7107-7134
From an Engineer's Perspective: Evaluation of the Invested Effort and the Resulting Benefits of Artificial Neural Networks in Proton Exchange Membrane Water Electrolysis Development
Authors: Rex Alexander , Trinke Patrick , Eckert Christoph , Bensmann Boris , Hanke-Rauschenbach Richard 
Published: November 2022

Machine learning approaches have become increasingly important in engineering research and development in recent years, and the first steps in this field can also be found at proton exchange membrane water electrolysis (PEMWE) development [1]. Well-known conventional simulation models for engineers are usually based on physical and empirical equations, with different approaches depending on the desired model depth. However, especially for the simulation of complex processes, model formulation and parametrization with sufficient accuracy are often challenging, with these types of models reaching their limits. In contrast, data-driven models use machine learning approaches to reproduce the desired processes based on large data sets and do not require physical or empirical model formulations [2]. For decision making on the deployment of machine learning methods, the effort required for familiarization, conceptual design, and implementation is the crucial aspect to answering the question of beneficial gain. Our conference contribution aims to answer these questions regarding invested effort and resulting benefit through a self-experiment using the example of artificial neural networks (ANN) in PEMWE research. It is intended to guide engineers interested in machine learning methods without prior knowledge, addressing their questions and ultimately assisting them in decision-making.
Our proposed research is shown in Figure 1 and consists of conceptualizing and programming ANN for two application cases, one for high-frequency resistance (HFR) regression and the other for PEMWE single-cell aging prediction. Here, the processes of familiarization time, conceptualization, and implementation of ANN are transparently presented from an engineer's perspective. The modeling results are evaluated in terms of their utility to the user. The data sets for training and validating the ANN to calculate HFR are generated using a physics-based simulation model. For aging prediction, the datasets are based on experimental data obtained from accelerated stress tests (AST) of a PEMWE single cell.
Our contribution finalizes with an assessment of the profit growth of engineering applications for pioneers in the field of machine learning methods.
Figure 1. Scheme for the evaluation of PEMWE single cells by artificial neural networks from an engineering perspective.
References:
[1] Bensmann, B., et al. "An engineering perspective on the future role of modelling in proton exchange membrane water electrolysis development." Current Opinion in Chemical Engineering (2022) (accepted)

[2] Mistry, A., et al. "How machine learning will revolutionize electrochemical sciences." ACS energy letters 6.4 (2021): 1422-1431.

Figure 1
Anode Catalyst Durability and Accelerated Stress Tests in Proton Exchange Membrane-Based Low Temperature Electrolysis
Authors: Alia Shaun M , Reeves Kimberly S. , Yu Haoran , Kropf A. Jeremy , Kariuki Nancy N. , Park Jaehyung , Myers Deborah J. , Cullen David A. 
Published: November 2022

Hydrogen has unique advantages as an energy carrier, with a high energy density and abilities for long term storage and conversion between electricity and chemical bonds. Although hydrogen currently has a significant role in transportation and agriculture, its use in energy consumption overall has been limited, particularly in the case of electrochemical water splitting. With decreasing electricity prices, electrolysis cost reductions can be achieved and allow for an opportunity for greater use.(1) While load-following renewable power sources can reduce feedstock cost, further cost reductions can be achieved by reducing the platinum group metal (PGM) content.(2) Efforts are needed to understand and mitigate electrolyzer degradation, particularly when accounting for lower PGM loadings and intermittent operation.
In this presentation, studies related to anode catalyst durability will be discussed and include the impact of individual stressors, observed degradation mechanisms, and the development of catalyst-specific accelerated stress tests. Membrane thickness and ohmic losses were deconvoluted from catalyst layer durability experiments, allowing for a transition from potential-driven parametric observations to current-driven stress tests for advanced materials and coating processes. Expanded studies have incorporated advanced materials, including higher surface areas, different oxide compositions, supports, and multicomponents. Kinetic improvements were found to lessen load requirements and can mitigate catalyst loss. Cell performance loss during extended operation, however, tended to qualitatively correspond to ex-situ dissolution rates and less stable materials accelerated catalyst layer thinning, migration into the membrane, and interfacial tearing. Perspectives on anode catalyst development will be discussed and increasing site-access and utilization further into the catalyst layer is needed to better understand the role of advancements in mitigating electrolyzer durability losses.
[1] B. Pivovar, N. Rustagi and S. Satyapal, The Electrochemical Society Interface, 27, 47 (2018).
[2] K. Ayers, N. Danilovic, R. Ouimet, M. Carmo, B. Pivovar and M. Bornstein, Annual Review of Chemical and Biomolecular Engineering, 10, 219 (2019).
[3] Electron microscopy was performed at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility.
(Invited) Bipolar Membranes with a 3D Junction of Interlocking Electrospun Fibers
Authors: Yang Zezhou , Wycisk Ryszard , Pintauro Peter N. 
Published: November 2022

Bipolar membranes (BPMs), typically laminated layers of anion-exchange and cation-exchange polymers, have the unique capability of splitting water at a potential near 0.83 V. Such membranes are used in electrodialysis membrane separation processes. They also have applications in water electrolyzers, CO2 electrolysis cells, and self-humidifying fuel cells. We report here on recent developments regarding BPMs with a high interfacial area, 3D nanofiber junction.
Membranes were prepared by first creating a bipolar junction layer, by the simultaneous electrospinning of anion-exchange and cation-exchange polymers, with the addition of catalyst nanoparticles to facilitate water splitting. Solvent vapor exposure and hot-pressing closed all interfiber pores, to create a dense film of interpenetrating and interlocking nanofibers of positively and negatively charged polymers. In one fabrication method, dense films of solution cast anion and cation-exchange polymers were hot-pressed onto the opposing surfaces of the junction layer to create a tri-layer BPM. Membranes were also fabricated by electrospinning all three layers of the BPM: first spinning anion-exchange fibers, followed by dual fiber spinning with catalyst spraying, and then spinning only cation-exchange fibers. Solvent exposure and hot-pressing closed all interfiber voids.
BPMs were made with a junction layer 12-15 mm thick, where the total membrane thickness was 50-80 mm. Membranes were prepared with both hydrocarbon and fluoropolymer ionomers, e.g., sulfonated poly(ether ether ketone) or perfluorosulfonic acid as the cation-exchange polymer and either quaternized poly(phenylene oxide), AEMIONä (an imidazolium-based polymer sold by Ionomr Innovations, Inc.), or PiperION (a poly(aryl piperidinium) from Versogen) as the anion-exchange polymer. A variety of different junction layer catalysts powders were examined, including Al(OH)3 and graphene oxide. Membranes were evaluated in an H-cell for the collection of steady-state current-voltage data and in a flow cell for long-term constant current water splitting (electrolysis) operation, typically with an aqueous Na2SO4 electrolyte. The 3D junction membranes performed exceptionally well: (i) the water splitting potential was low (near the expected value of 0.83 V), (ii) the transmembrane voltage drop was small at high currents (e.g., a voltage drop of 1.1 V up to 1.1 A/cm2), and (iii) the extended bipolar reaction zone for water splitting with interlocking fibers allowed for high current density operation with no evidence of membrane degradation.
In this talk, the effect of membrane composition (the type/amount of anion and cation exchange polymers and choice of catalyst) and structure (the thickness of the layers) on short-term and long-term membrane performance will be discussed. Results will be presented for operating the bipolar membrane in water splitting and water generation modes.
Engineering of Electrodes and Operating Conditions for Pure-Water-Fed Anion Exchange Membrane Water Electrolyzers
Authors: Bohannon Jasmine , Duanghathaipornsuk Surachet , Ul Hassan Noor , Divekar Ashutosh , Zulevi Barr , Kohl Paul , Mustain William Earl 
Published: November 2022

Many industrial processes such as petroleum refining, ammonia production, and metal refining have hydrogen gas as a feedstock. Hydrogen gas can be produced via fossil fuel reforming, photo-electrochemical conversion, thermochemical water decomposition, as well as water electrolysis. Among the various water electrolysis technologies, anion exchange membrane water electrolyzers (AEMWEs) possess possible qualities that will allow for them to out-compete incumbent alkaline electrolyzers and proton exchange membrane electrolyzers PEMWEs). AEMWEs have to possibility to combine platinum group metal–free (PGM-free) catalysts, low-cost cell components and operation at high pressure. It is also desirable for AEMWEs to be operated with a pure water feed, high performance and long life – all of which has been elusive thus far.
In this presentation, we will demonstrate device engineering pathways to achieve high performance with pure-water-fed AEMWEs. This was accomplished by optimizing the type and amount of electrocatalyst on both anode and cathode alongside the flow conditions and operating temperature. The optimized pure-water-fed AEMWEs have been successfully operated at steady-state at a voltage below 1.90 V at 1.0 Acm-2 at 80 °C. Differences will be highlighted between DI water and electrolyte-fed systems. The importance of pre-treatment to ensure pure DI-water operation will also be discussed. This work emphasizes the importance of engineering electrodes and operating conditions to reach the highest performance of pure-water-fed AEMWEs, which is expected to allow these devices to out-compete existing water electrolysis technologies.
PGM-Free AEM Electrolyzer Cell Development for Solar Power Integration
Authors: Zhong Sichen , Lattimer Judith , Strasser Derek James , McKone James , Kaur Manjodh , Hu Keda , Yan Yushan 
Published: November 2022

The increasing availability of renewable energy sources, especially solar power, coupled with the desire to reduce greenhouse gas emissions, has led to an increased interest in using renewables to satisfy global energy demand. Hydrogen is an attractive alternative to fossil fuels due to its potential for emissions reductions and advantages in storage and transportation. Direct solar-to-hydrogen generation would enable the conversion of renewable energy and water into a storable fuel, thereby drastically reducing carbon emissions. However, current hydrogen production from commercial PEM electrolysis systems requires acidic environment which necessitates the use of expensive platinum group metal (PGM) catalysts and corrosion resistant cell stack components. Thus, a stable, robust, and inexpensive anion exchange membrane and PGM-free catalysts are needed to make alkaline solar water splitting commercially viable as a replacement for the expensive PEM system.
We have developed a fully PGM-free electrolyzer using anion exchange membrane (AEM) in an alkaline environment that operates at 80 °C. Using carbon supported NiMo as hydrogen evolution reaction (HER) catalyst and NiFe as oxygen evolution reaction (OER) catalyst, in combination with commercially available AEM from Versogen, we were able to achieve a stable performance of 1.504 V at 100 mA/cm2, compared with baseline PGM cell at 1.508 V, in alkaline environment. At 2 A/cm2, the fully PGM-free cell demonstrated 200 mV higher potential compared to the PGM baseline cell at 2.009 V. Furthermore, we were able to run more than 200-hour at constant current density 2 A/cm2, with 85 mV performance loss. Further developments in catalyst performance and membrane stability, as well as integration with photovoltaics to enable hydrogen production from water, are underway.

Acknowledgement: The project is financially supported by the Department of Energy’s Office of Science under the Grant DE-SC0020576