bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Modelling and Simulation for the Search for New Active Materials for Redox Flow Batteries - Results of the International Project Sonar
Authors: Noack Jens , Baudrin Emmanuel , Fornari Rocco , Franco Alejandro A. , Gerlach Daniel , Guan Xinjie , Hamaekers Jan , Maaß Astrid , Menictas Chris , Mourouga Gael , Nirschl Hermann , Roznyatovskaya Nataliya , Schaerer Roman , Schumacher Jürgen , de Silva Piotr , Skyllas-Kazacos Maria , Wlodarczyk Jakub , Wolf Amadeus , Yu Jia 
Published: July 2022

Due to the characteristics of flow batteries, this technology is ideally suited for low-cost storage in the range of a few hours and thus for load balancing as stationary storage in grids with high amounts of renewable energy [1]. Today, a large number of different active materials for flow batteries are known, although only a few have been commercialised [2]. Basically, the energy supply and thus also the required storage should be sustainable, i.e. not cause resource problems and not be harmful to humans and the environment. A potential for a huge range of possibilities is offered by organic active materials, which should be used especially in aqueous solutions. Due to the immense possibilities, classical synthesis and testing is extremely lengthy and costly. An alternative can be model-based high-throughput screening, where by simulating the properties of active materials in the electrolyte and the battery itself, computer-based simulations can be used to conduct the search.
The SONAR project is an EU-funded project in which 7 different institutions from the EU, Switzerland and Australia are developing a high-throughput screening method capable of finding new active materials for redox flow batteries. The principle is a serial coupling of different size scales, combined with molecule generation and machine learning. The chemical structure of a candidate is generated by a molecule generator and then its atomistic properties, kinetics, side reactions and cell properties are iteratively calculated with exclusion criteria.
In this talk we will give an overview of 2 years of research in this project in the areas of machine learning for high throughput screening, DFT based quantum mechanics modelling, kinetics Monte Carlo methods for meso-scale, 0D cell modelling, 3D cell modelling, stack modelling and techno-economics.

[1] B. Dunn, H. Kamath, J.-M. Tarascon, Science 2011, 334, 928–935.

[2] J. Noack, N. Roznyatovskaya, T. Herr, P. Fischer, Angew. Chem. Int. Ed. 2015, 54, 9776–9809.

Figure 1
Optimization of Porosity Distribution in Gas Diffusion Electrodes for CO2 Electrolysis
Authors: Ehlinger Victoria Marie , Roy Thomas , King Alex , Baker Sarah , Duoss Eric B , Weber Adam Z. , Beck Victor A 
Published: July 2022

The criteria dictating the performance of gas diffusion electrodes (GDEs) for CO2 electrolysis are not well understood, due to the complex and highly coupled relationships of the underlying physical and chemical phenomena. In addition, a number of key performance indicators (KPIs) have been identified (e.g., Faradaic efficiency, reaction selectivity, single-pass conversion, and productivity), and optimizing for any single metric often leads to inherent tradeoffs. Consequently, much recent work has focused on understanding how operational and architectural parameters control GDE performance. The porous catalyst supports and diffusion media in these devices are critical components as they mediate the transport and reactive processes. The microstructure of these components influences the balance between the electrochemical surface area, which dictates CO2 consumption, and mass transfer of the aqueous and gaseous species. Traditional porous media is often spatially homogeneous and provides limited opportunity to tailor this balance. In contrast, novel advanced manufacturing methods have now enabled researchers to create electrodes with variable porosity that can be tuned for optimal performance. To explore the impact of locally altering the porous media structure, we leverage previous modeling work by Weng et al. to allow for spatially varying porosity. Further, we couple the forward simulation to adjoint based optimization algorithms to determine optimal porosity distribution in the diffusion media and catalyst layer of a GDE. The cost functions for the optimization are derived from the previously mentioned KPIs. Finally, the performance of the resultant spatially varying porosity GDEs is compared to the performance of homogenous porosity GDEs, and we identify key features of the porosity distribution leading to improved performance.

Weng, Lien-Chun, Alexis T. Bell, and Adam Z. Weber. "Modeling gas-diffusion electrodes for CO2 reduction." Physical Chemistry Chemical Physics 20.25 (2018): 16973-16984.

This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
LLNL-ABS-830082
Flexible Laser-Patterned Carbon Coatings for Sensing and Energy Applications
Authors: Hepp Marco , Derr Katharina , Butz Benjamin , Wang Huize , Jimenez-Calvo Pablo , Strauss Volker 
Published: July 2022

Fabricating electronic devices from natural, renewable resources has been a common goal in engineering and materials science for many years. In this regard, carbon-based coatings are of significance due to high availability of the raw materials and their environmental degradability. Carbonized materials and composites thereof have been proven as promising candidates for a wide range of future applications in flexible electronics, optoelectronics, energy storage or catalytic systems [1]. On the industrial scale, however, their application is inhibited by tedious and expensive preparation processes and a lack of control over the processing and material parameters.
A promising tool to tackle that challenge is carbon laser-pattering (CLaP) allowing for the defined and site-selective synthesis of functional carbon-based materials for flexible on-chip applications [2]. Versatile inks, based on naturally occurring (molecular) starting materials are used to produce films, which are carbonized with a CO2-laser to obtain functional patterns of conductive porous carbon networks [3]. By chemical and physical fine-tuning of the laser patterned carbons (LP-C), we developed high-performance flexible resistive chemical and mechanical sensors. Their properties make them applicable in many fields e.g., robotics, bionics and even health monitoring.
In this contribution, we present both, the material’s synthesis and tailored properties as well as in-depth microscopic and spectroscopic cross-sectional analyses of such coatings by advanced transmission electron microscopy, which provide unprecedented insights into the microstructure and local chemistry/bonding of laser-patterned carbon [4]. In that regard, we discuss the challenging cross-sectional preparation of such porous and sensitive structures by advanced ultramicrotomy. The gained insights in structure formation and local functionality pave the way for the utilization of alternative fast, large-scale carbonization methods such as rapid thermal annealing.
[1] D. Jariwala, V. K. Sangwan, L. J. Lauhon, T. J. Marks, M. C. Hersam, Chem. Soc. Rev. 2013, 42, 2824–2860.
[2] R. Ye, D. K. James, J. M. Tour, Adv. Mater. 2019, 31, 1803621.
[3] S. Delacroix, H. Wang, T. Heil, V. Strauss, Adv. Electron. Mater. 2020, 6, 2000463.
[4] M. Hepp, H. Wang, K. Derr, S. Delacroix, S. Ronneberger, F. Loeffler, B. Butz, V. Strauss, NPJ Flex. Electron. 2021, accepted for publication
(Keynote) Molecular Engineering Strategies for Symmetric Aqueous Organic Redox Flow Batteries
Authors: de Silva Piotr 
Published: July 2022

In this contribution we use electronic structure calculations to reveal structure-property relationships for symmetric aqueous organic redox flow battery (RFB) materials. Unlike normal asymmetric RFBs, the symmetric ones are based on bipolar electrolytes that exist in at least three oxidation states and can undergo a minimum of two distinct redox processes. We compute from first principles the redox potentials of selected electrolytes based on quinone, pyrazine, and pyridazine redox-active moieties.[1] The objective is to understand how the interaction between the redox units affects the potentials and solvation energies. We find that electronic interaction between redox units and intramolecular hydrogen bonding can be exploited to tune the difference between the redox potentials, i.e., the theoretical voltage of the battery. The redox potentials can be further fine-tuned in either direction by adding substituents. Starting from these observations, we formulate a set of rules that will help in finding improved electrolytes for symmetric RFBs.
[1] R. P. Fornari, M. Mesta, J. Hjelm, T. Vegge, P. de Silva, “Molecular Engineering Strategies for Symmetric Aqueous Organic Redox Flow Batteries”, ACS Materials Lett.
2020, 2, 3, 239–246.
A Critical Approach to Multi-Electron Materials for High Energy Density Non-Aqueous Redox Flow Batteries
Authors: Daub Nicolas 
Published: July 2022

Redox flow batteries (RFBs) are very promising storage systems in the transition towards renewable energy sources. They can be broadly classified in aqueous and non-aqueous systems. Last-named operate with organic solvents, which allow for a much broader potential window (up to three times higher) compared to water. Combination of organic solvents with organic redox active materials could pave the way for all carbon-based RFBs with superior energy densities compared to aqueous systems.
In this contribution, newly developed organic electrolytes will be presented, focusing on their performance as RFB materials in acetonitrile with quaternary ammonium electrolyte salts. To push the limits of energy density, we investigated multi-electron reduction and oxidation reactions on a single molecule.
As catholyte, tetrathiafulvalene (TTF) as a core structure was used. The unsubstituted TTF exhibits two reversible oxidation events (-0.04 and +0.34 V vs Fc/Fc+) but a poor solubility in acetonitrile. To optimize this and to achieve a higher oxidation potential a series of molecules with different side chains was synthesized. The resulting solubilities led to volumetric capacities of up to 71 Ah/L for the newly designed compounds. Electrochemical cycling stability was evaluated in bulk electrolysis, UV-Vis-NIR and flow cycling experiments.
Current state-of-the-art anolytes based on N-methylphthalimide compounds exhibit one reversible reduction pair at a desirable low reduction potential (-1.87 V vs Fc/Fc+) and good cycling stability in bulk electrolysis experiments.[1] Expanding on this structure, new derivatives with one or two additional functional imide groups per phthalimide core were synthesized. Consequently, molecules with a single (-1.87 V vs Fc/Fc+), double (-1.26 and -1.88 V vs Fc/Fc+) and triple reduction event (-1.02, -1.65 and -2.37 V vs Fc/Fc+) can be obtained. To optimize their solubility in acetonitrile, a series of molecules with different side chains was synthesized for each of the three core structures. Determination of the solubility led to volumetric capacities of up to 66 Ah/L for the newly developed compounds. Additionally, we tested the electrochemical cycling stability in bulk electrolysis, UV-Vis-NIR, coin cell and flow cycling experiments. In the final flow battery, a high energy density of 24 Wh/L was achieved (at 1 M of transferred electrons).[2]

All of this led to a critical comparison between the different molecular designs, cumulating in design rules that will influence future designs of the organic redox active compounds for organic RFBs.

[1] Wei, X.; Duan, W.; Huang, J.; Zhang, L.; Li, B.; Reed, D.; Xu, W.; Sprenkle, V.; Wang, W. A High-Current, Stable Nonaqueous Organic Redox Flow Battery. ACS Energy Lett.
2016, 1, 705−711

[2] Daub, N.; Janssen, R. A. J.; Hendriks, K. H. Imide-Based Multielectron Anolytes as High-Performance Materials in Nonaqueous Redox Flow Batteries. ACS Appl. Energy Mater.
2021, 4, 9, 9248–9257
Dicationic Heteroaryl Pyridinium As a Highly Stable, Soluble, and Crossover-Resistant Anolyte for Nonaqueous Redox Flow Batteries
Authors: Ahn Seongmo , Jang Jin Hyeok , Joo Jung Min , Byon Hye Ryung 
Published: July 2022

Recently, redox flow batteries (RFBs) have emerged as one of the promising candidates for safe and economical grid-scale energy storage system (ESS) that store the intermittent energies such as wind or solar energy. Unlike the conventional aqueous vanadium RFBs, the design of new molecules in nonaqueous RFB (NRFB) has been in the spotlight for the high energy density, cycling stability, and low cost. Among the redox active materials, in particular, organic molecule has various structures through functionalization, and thus its redox potential, solubility, and chemical stability can be controlled. However, there are only a few viable negative-side redox electrolyte, called a negolyte (or anolyte) to date, and even the reported negolytes have suffered from low solubility and stability, and severe crossover problems for long-term cycling.
Here we show the systematic design strategies for pyridinium-based organic redox molecule to enhance the its stability and solubility and suppress the crossover rate for NRFB. A benzo[d]thiazole ring, which provides an electron-withdrawing effect, was introduced at the C4 position of pyridinium core by Pd catalyzed C-H arylation. The addition of the π-conjugation system to the pyridinium redox core was key to enhance chemical and electrochemical stability, resulting in negatively low redox potential of -1.19 ~ 1.21 V vs. Fc/Fc+. The solubility of pyridinium derivatives was significantly enhanced from 0.26 M to 1.00 M in acetonitrile by simple anion exchange from tetrafluoroborate (BF4
-) or hexafluorophosphate (PF6
-) anion to bis(trifluoromethanesulfonyl)imide (TFSI-) anion. Moreover, exchanging the functional group on N of pyridinium from methyl group to cationic 3-(trimethylammonio)propyl (TMAP) group suppressed the crossover rate with an anion-exchange membrane in the NRFB. 4-(benzo[d]thaizol-2-yl)-1-(3-(trimethylammonio)propyl)pyridin-1-ium (TMAP-BTP) led to electrochemical stability in symmetric cell, showing a capacity decay rate of 0.0083% per cycle. Contrary to the results of only 60% capacity retention after 100 cycle in full cell with 4-(benzo[d]thaizol-2-yl)-1-methylpyridin-1-ium (BTP) as negolyte, in the case of full cell with TMAP-BTP as negolyte, the capacity retention was significantly increased, showing 89.8 % after 100 cycle, which is ~0.08% capacity decay rate per cycle. In this presentation, I will demonstrate the more detailed design strategies, cycling performances, and electrolyte analysis. (Figure
1).1

References

Ahn, J. H. Jang, J. Kang, M. Na, J. Seo, V. Singh, J. M. Joo and H. R. Byon, ACS Energy Lett., 6, 3390 (2021).

Figure 1
Understanding Capacity Fade in Organic Redox-Flow Batteries Using Uncertainty Quantification Techniques and Zero-Dimensional Modeling
Authors: Modak Sanat Vibhas , Shen Wanggang , Owhoso Fiki G , Huan Xun 
Published: July 2022

We introduce the use of Bayesian uncertainty quantification to provide data-informed assessments of the probability of different hypotheses of reactant decay, and to estimate reactant decay parameters from experimental data with quantified uncertainty. As a case study, we use these techniques to extract rate constants describing the nucleophilic attack of quinone-based RFB reactants by water, as measured using in operando ultraviolet-visible spectrophotometry. We then introduce a zero-dimensional electrochemical flow cell model3 which can simulate capacity fade given a reactant decay mechanism and associated parameters, and the cycling protocol. This work has the potential to shed light on the relationship between capacity fade and reactant decay in various organic RFB chemistries, and to enable prediction of the lifetimes of commercial-scale RFBs.
(1) Brushett, F. R.; Aziz, M. J.; Rodby, K. E. On Lifetime and Cost of Redox-Active Organics for Aqueous Flow Batteries. ACS Energy Letters
2020, 879-884. DOI: 10.1021/acsenergylett.0c00140. Dieterich, V.; Milshtein, J.; Barton, J.; Carney, T.; Darling, R.; Brushett, F. Estimating the Cost of Organic Battery Active Materials: A Case Study on Anthraquinone Disulfonic Acid. Translational Materials Research
2018.
(2) Kwabi, D. G.; Ji, Y.; Aziz, M. J. Electrolyte Lifetime in Aqueous Organic Redox Flow Batteries: A Critical Review. Chemical Reviews
2020.
(3) Modak, S.; Kwabi, D. G. A Zero-Dimensional Model for Electrochemical Behavior and Capacity Retention in Organic Flow Cells. Journal of The Electrochemical Society
2021, 168 (8), 080528. DOI: 10.1149/1945-7111/ac1c1f.
(Invited) Hydrogen Oxidation Reaction (HOR) on Carbon-Capped Pd/C in Alkaline Media
Authors: Doan Huong , Sgarbi De Moraes Ricardo , Chatenet Marian 
Published: July 2022

It is no secret alkaline fuel cells (AFC) using a liquid electrolyte (usually concentrated KOH) have assets over their proton-exchange membrane counterparts, in particular in niche applications where the latter are challenged by too harsh operating/environmental conditions [1]. AFC can also, in theory, use non-Pt catalysts at their electrodes without detrimental durability issues. However, recent studies from our group showed that Pt/C and Pd/C were very sensitive to the metal nanoparticles detachment from the carbon owing to their propensity to catalyze the carbon-support corrosion upon repeated alternation of the potential below/above their metal oxide potential (which is unavoidable at the anode upon start/stop of the fuel cell) [2-5].
In this presentation, it is highlighted that more robust hydrogen oxidation catalysts can be prepared by tailoring a carbon cap around the metal nanoparticles, in particular for palladium as the catalyst metal. Such “carbon-capped” Pd/C nanoparticles (ex. PdG2/C) exhibit a good compromise between their HOR activity and long-term stability (Figure 1), evaluated by identical location transmission electron microscopy upon accelerated stress tests (0.1 - 1.23 V vs. RHE stepped by 3 s – 3 s, 1000 times) (Figure 2). Their properties are very advantageous over non-capped (classical) Pd/C nanoparticles, demonstrating the interest of this strategy for the development of active and durable HOR catalysts for AFC anodes.

References

[1] G.F. McLean, T. Niet, S. Prince-Richard, N. Djilali, Int. J. Hydrogen Energy 27 (2002) 507-526.
[2] A. Zadick, L. Dubau, N. Sergent, G. Berthomé, M. Chatenet, ACS Catal. 5 (2015) 4819-4824.
[3] A. Zadick, L. Dubau, U.B. Demirci, M. Chatenet, J. Electrochem. Soc. 163 (2016) F781-F787.
[4] C. Lafforgue, A. Zadick, L. Dubau, F. Maillard, M. Chatenet, Fuel Cells 18 (2018) 229-238.
[5] C. Lafforgue, F. Maillard, V. Martin, L. Dubau, M. Chatenet, ACS Catal. 9 (2019) 5613−5622.

Figure 1
How Hydrogen Evolution and Oxidation Reactions Proceed at the Platinum-Electrolyte Interface in Aqueous Solution
Authors: Jia Qingying , Sun Qiang , Myrthil Nathalie , Lopez Steven , Oliveira Nicholas J , Yan Yushan , Li Jingkun , Tyukhtenko Sergiy , Guo Jason 
Published: July 2022

The hydrogen evolution and oxidation reactions (HER/HOR) are the most fundamental reactions in electrochemistry. They are also the electrochemical reactions taking place in practical devices such as H2 fuel cells and electrolyzers for the conversion between hydrogen fuel and electricity. Despite their fundamental and practical importance, the HER/HOR kinetics has remained not explicitly clear even for the platinum (Pt) electrode that has been mostly studied. This is manifested by the lack of consensus on why the HER/HOR rate of Pt is about two orders of magnitude slower in alkaline (pH = 0) than in acid (pH = 13),1 a long-standing puzzle in electrochemistry. Clear understanding of electrochemical reaction kinetics requires clear understanding of the charge transfer and chemical transformation at the electrode-electrolyte/membrane interface (EEI), which is however hampered by the lack of means to explore the complex electrochemical processes at the EEI in situ/operando.
Herein, by employing a set of N-methylimidazoles as the HER/HOR promotors and interface probes, we gave a reasonable explanation on how the HER/HOR of Pt proceeds within the EEI in aqueous solution.2 A combination of in situ spectroscopic characterization on the EEI showed that the N-methylimidazoles promoted the HER/HOR of Pt in alkaline solution by reorientating interfacial water against the interfacial electric field. We accordingly proposed that the HER/HOR in acidic and alkaline solution proceeds via diffusion of proton and hydroxide, respectively, through the H-bond network of interfacial water by the Grotthuss mechanism (Figure 1). We further demonstrated that adding 1,2-dimethylimidazole into the alkaline solution fed into the cathode of an anion exchange membrane electrolyzer led to an 40% performance improvement. The diffusion roles of interfacial water unraveled here may apply to many other electrochemical processes in aqueous solution.

Acknowledgements

This work was supported by the Office of Naval Research (ONR) grant N000141712608. This research used beamline 7-BM (QAS) of the National Synchrotron Light Source II, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory Contract DE-SC0012704. Beamline operations were supported in part by the Synchrotron Catalysis Consortium Grant DE-SC0012335.

Durst, J. et al. New insights into the electrochemical hydrogen oxidation and evolution reaction mechanism. Energy Environ. Sci.
7, 2255-2260 (2014).

Sun et al. Mechanistic insights into pH-dependent hydrogen electrocatalysis by flipping interfacial water. Under revision by Nat. Energy.

Figure 1
(Keynote) Oxygen Reduction and Evolution in Ca2+ Containing DMSO on Atomically Smooth and Rough Pt and Au – Towards a Generalized ORR Mechanism in M2+ Containing DMSO
Authors: Koellisch-Mirbach Andreas , Bawol Pawel Peter , Park Inhee , Baltruschat Helmut 
Published: July 2022

We demonstrate via cyclic voltammetry, differential electrochemical mass spectrometry (DEMS) and rotating ring disk electrode (RRDE) investigations with variation of the electrode surface roughness and atomically surface structure, that the CaO/CaO2 adsorbate layer formation determines the ORR product distribution. We found that on Pt electrodes peroxide is formed on the clean electrode, whereas superoxide is formed at the adsorbate covered electrode. We furthermore identified four key parameters, which strongly affect the ORR product distribution.

The electrode oxide interaction: A strong interaction shifts the product distribution to larger superoxide contribution.

The alkaline earth metal oxide interaction: A strong interaction shifts the product distribution to larger peroxide contribution.

The electrode surface area: A large electrode surface area delays the completion of the adsorbate layer and increases the peroxide contribution.

Electrode surface defects: Defects allow for faster nucleation and thus foster the adsorbate formation, which finally leads to a larger superoxide contribution.

Finally, reviewing earlier results of our group we provide a more general mechanism for the oxygen reduction alkaline earth metal cation containing DMSO, for a variety of electrode materials.
[1] A. Koellisch-Mirbach, I. Park, M. Hegemann, E. Thome and H. Baltruschat, ChemSusChem, (2021).
[2] P.P. Bawol, A. Koellisch-Mirbach, C.J. Bondue, H. Baltruschat and P.H. Reinsberg, ChemSusChem, 14 (2021) 428.