bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Advanced Hydrogen-Bromine Fuel Cells for Energy Storage
Authors: Lin Guangyu , Chong Pau Ying , Nguyen Trung Van , Yarlagadda Venkata , Wycisk Ryszard , Pintauro Peter N. , Tucker Michael C , Weber Adam Z , Bates Michael , Mukerjee Sanjeev 
Published: February 2020

The hydrogen-bromine fuel cell has been shown to be a promising candidate for large-scale energy storage due to its fast kinetics, fully reversible electrodes and low chemical costs. However, today's conventional hydrogen-bromine fuel cells use very expensive membrane materials (such as Nafion®) and platinum catalysts that can be poisoned and corroded when exposed to HBr and Br2. An advanced H2-Br2 fuel cell is being developed with reduced cost and increased durability for energy storage. We have successfully developed new composite membranes with higher perm-selectivity at a fraction of the cost of Nafion membranes; new catalysts possessing excellent activity and durability in HBr/Br2 environment and novel electrode/cell designs with superior cell performance. The advanced H2-Br2 fuel cell is high-power, high-efficiency with substantially increased durability and reduced cost. The latest progress in development will be discussed.
Acknowledgements

This work was funded by Advanced Research Projects Agency-Energy (ARPA-E) of the U. S. Department of Energy under Award No. DE-AR0000262.

References

M.C. Tucker, K.T. Cho, A.Z. Weber, G. Lin and T.V. Nguyen, Journal of Applied Electrochemistry, October 2014.

H. Kreutzer, V. Yarlagadda and T.V. Nguyen, J. Electrochem. Soc., 159, F331 (2012).
Two-Point State-of-Charge Determination in Lithium-Ion Battery Packs
Authors: Dubarry Matthieu , Devie Arnaud , Liaw Bor Yann 
Published: February 2020

The state-of-charge (SOC) estimation is of extreme importance for the reliability and safety of battery operation in large scale energy storage systems. How to estimate SOC for an assembly of cells in a battery pack remains a subject of great interest. Here, a viable method for SOC determination and tracking for multi-cell assemblies is proposed and validated. Using 3S1P strings as an example, an inference of SOC is illustrated in a battery assembly based on an accurate open pack voltage (OPV) versus SOC (i.e. OPV = ¦(SOC)) function. The proposed method only requires the measurement of the rest cell voltages of the single cells on two distinct occasions.
This new method offers great benefits to SOC calibration and tracking, which should improve the accuracy of any SOC tracking method (Figure 1). This method is not calculation intensive and could easily be implemented in any BMS. Additionally, we introduced two parameters which could be used to characterize and follow the imbalance evolution within a pack, and thus, enable remaining useful life determination with improved accuracy.
Coupled with our other diagnostics tools we believe that this approach could lead to a significant improvement of the quality of BMS SOC tracking and SOH diagnostics, for all applications where large battery assemblies are needed. As a matter of fact, and to the best of our knowledge, this is the first time where the pack-level (imbalance) and cell-level (aging) degradation factors of a battery pack could be distinguished and accurately quantified without any disassembly or maintenance downtime required.
Figure 1: Comparison between experimental data and simulation with and without the proposed method.

Figure 1
(Invited) Operando Methods for the Study of Energy Materials
Authors: Abruña Héctor D. 
Published: February 2020

This presentation will deal with the development of operando methods for the study and characterization of fuel cell and battery materials. The presentation will begin with a brief overview of the methods employed. Particular emphasis will be placed on the use of X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS), transmission electron microscopy (TEM) under active potential control, confocal Raman and differential electrochemical mass spectrometry (DEMS). The utility of these methods will be illustrated by selected examples including conversion reactions of Mn3O4 as anode material for lithium ion batteries (LIBs), spectroscopic studies of Li/S batteries and the use of DEMS to characterize electrolyte systems for LIBs. The use of operando TEM will be illustrated by studies of fuel cell catalyst degradation and coalescence and lithiation/de-lithiation dynamics of LiFePO4 via energy-filtered TEM. The presentation will conclude with an assessment of future directions.
(Allen J. Bard Award) The Electrochemical Nucleation and Physical Behavior of Hydrogen Nanobubbles
Authors: White Henry S , Chen Qianjin , German Sean R. , Wiedenroth Hilke , Luo Long , Feldberg Stephen W. 
Published: February 2020

Gas nanobubbles formed at solid/liquid interfaces have received significant attention during the past decade due to their remarkable properties. For instance, interfacial nanobubbles may exist for hours or days, in contrast to their expected short lifetime (< 1 s, based on the theoretical rate of gas dissolution from a nanoscale bubble). We have developed an electrochemical approach for investigating the formation and properties of a single nanobubble of H2 with a radius between 5 and 50 nm. To create a H2 nanobubble, a Pt nanodisk electrode, shrouded in a glass sheath, is used to reduce H+ in a concentrated acid solution, creating a supersaturated solution of H2 adjacent to the electrode surface. As the electrode potential is scanned towards negative potentials, the current arising from H2 generation increases exponentially and then suddenly decreases to near background levels, signaling a liquid-to-gas phase transformation associated with the formation of a single nanobubble at the electrode surface. The critical concentration of dissolved H2 required for nanobubble nucleation, obtained from the electrochemical response, is measured to be ~0.25 M, corresponding to ~310-fold supersaturation of H2. We estimate the critical size of the smallest stable H2 gas bubble nucleus to be ~4 nm; this nucleus grows and covers the Pt nanodisk surface until it becomes pinned at the Pt/glass interface. Thermodynamic relations indicate that the internal pressure within these nanobubbles is of the order of 100 atm.
The nanobubble experiments also provide insight into the structure and chemical dynamics of electrochemical three-phase solid/liquid/gas boundaries. We demonstrate that a steady-state residual current of ~100 pA, measured after bubble formation, results from continuous electrogeneration of H2 at the Pt/electrolyte/H2 gas interface; steady-state reduction of H+ is required to balanced the rate of H2 dissolution from the nanobubble into the solution. These experiments allow unique measurements of H+ reduction rates at a three-phase boundary, as well as estimation of the width of the three-phase boundary. We also report additional experiments that demonstrate that the stability and shape of H2 nanobubbles are sensitive to the applied pressure and to the presence of surfactants. Finally, we show that individual H2 bubbles can be electrochemically nucleated within nanopores.
Localized Investigations of the Electrochemical Properties of Lithium Battery Materials Using Micro-Pipets
Authors: Snowden Michael Edward , Mauzeroll Janine , Schougaard Steen Brian 
Published: February 2020

Lithium ion batteries are a commercially successful method for portable electrical energy, demonstrated by their use in portable electronics and the recent application as an alternative automotive power source to the internal combustion engine.1 However, for lithium ion batteries to be a competitive alternative to fossil fuels in the automotive industry, electrode materials with improved capacity and charge/discharge rates are required. As new anode and cathode materials are developed2 they are typically screened for advantageous properties by assembly into a working battery. This involves the fabrication of a film from a mixture of conductive material (e.g. carbon), a binder (e.g. polyvinylidene fluoride), and the active material of interest. A film is cast onto a conductive material to form the active electrode, before assembly within a coin cell. How the film is cast, the ratio of the individual components of the film, the drying procedure for the film and the final assembly of the coin cell can significantly alter the performance of the battery.3,4 In order to avoid misleading information about the effectiveness of a novel active material many coin cells are required to validate findings.
Here we present micro-pipet measurements5 which demonstrate the suitability of the technique for probing lithium ion battery materials. Specifically, we probed dispersions of active materials to determine the oxidation and reduction potentials, and the charge capacity of the material. Data obtained on candidate materials by the micro-pipet method was compared to coin cell measurements, to critically assess this technique for characterisation of active battery materials.
1) Wagner, F. T.; Lakshmanan, B.; Mathias, M. F.; J. Phys. Chem. Lett., 2010, 1 (14), 2204–2219
2) Whittingham, M.S.; Chem. Rev., 2004, 104 (10), 4271–4302
3) Bruce, P. G.; Scrosati, B.; Tarascon, J.-M.; Angew. Chem.-Int. Ed.
2008, 47 (16), 2930-2946
4) Ban, C.; Wu, Z.; Gillaspie, D. T.; Chen, L.; Yan, Y.; Blackburn, J. L.; Dillon A. C.; Adv. Mater. 2010, 22, E145–E149
5) Williams, C. G.; Edwards, M. A; Colley, A. L.; Macpherson, J. V; Unwin, P. R.
Volammetric and Chronopotentiometric Study of Nonstationary Process on Oxygen-Evolving Anodes in KF-Naf-AlF3-Al2O3
Authors: Suzdaltsev Andrey , Khramov Andrey , Limanovskaya Oksana , Zaikov Yuriy , Nekrasov Valentin 
Published: February 2020

Some specific aspects of mechanism and kinetics of the anode processes at Pt and Cu-Fe-Ni alloy in the KF-NaF-AlF3-Al2O3 melts in the temperature range of 725-800 °С were studied using cyclic voltammetry and chronopotentiometry.
Based on the obtained nonstationary volt-ampere dependencies a conclusion regarding similarity of the anode processes occurred at Pt and Cu-Fe-Ni, i.e. a stage of electrochemical oxidation is proved to precede a two-stage electrochemical evolution of the molecular oxygen. It was found that the rate of this stage depends significantly on the melt temperature.
Multi-Scale Theory in the Molecular Simulation of Electrolyte Solutions
Authors: Pratt Lawrence R , Zhang W. , You X. 
Published: February 2020

To define a role for AIMD simulation on the limited time and space scales accessible to those demanding methods, this paper organizes McMillan−Mayer theory, the potential distribution approach, and quasi-chemical theory to provide theory for the thermodynamic effects associated with long-length scales. The theory treats composition fluctuations that would be accessed by larger-scale calculations, and also longer-ranged interactions that are of special interest for electrolyte solutions. The quasi-chemical organization breaks-up governing free energies into physically distinct contributions: packing, outer- shell, and chemical contributions. Here we study specifically the outer-shell contributions that express electrolyte screening. For that purpose we adopt a primitive model suggested by observation of ion-pairing in tetraethylammonium tetrafluoroborate dissolved in propylene carbonate. Gaussian statistical models are shown to be effective physical models for outer-shell contributions, and they are conclusive for the free energies within the quasi-chemical formulation. With the present data set the Gaussian physical approximation obtains more accurate mean activity coefficients than does the Bennett direct evaluation of that free energy.

Figure 1
Multiscale Modeling of a Proton Exchange Membrane Fuel Cell: Effect of Electric Double Layer Structure
Authors: Castañeda Ramírez Sergio , Carmona Juan , Pérez Mendoza Alejandro Esteban , Ribadeneira Paz Rafael Esteban 
Published: February 2020

Proton Exchange Membrane Fuel Cells (PEMFCs) are very promising to generate electric energy for transport and electronic devices because they produce minimal pollutant emissions and can operate at low temperature [1]⁠. Despite of enormous progresses made to date, this technology has to reach all technical requirements in order to be competitive.
The presence of solvated cations as charge-transporting species has a direct influence on the potential profile at interfaces involved in PEMFCs. This leads to a shift in the electric potential acting on the reactants and modifies their activation energies. In this way, the rate of mass and charge transfer processes are determined by the electric double layer (EDL) morphology and structure. For instance, a simple modification in the medium permittivity close to the surface results in appreciable increase of the apparent reaction rate constant [2].
The importance of EDL structure on transfer mechanisms has led to several researches based on mean field theories and molecular simulations [3-4]. However, an integration of EDL structure simulations with PEMFC reaction model is still lacking. This will contribute to understand and cuantify the effect of electrolyte and solvent compositions on the reaction kinetics.
In order to simulate the EDL structure and its modifications with respect to applied potential and solution composition, it is required a proper molecular model that resembles the size, polar and chemical characteristics of reactants, electrolyte and solvent species involved in PEMFCs, which is proposed to carry out in this work by means of molecular dynamics (MD) simulations.
The results achieved by molecular simulations would enable to evaluate the modification of reaction rates by the EDL structure, under an applied potential in PEMFC. In order to accomplish this, it is employed the Stillinger-Weber interaction potential of water and platinum [7], coupled with electrostatic interactions for the molecular simulations of EDL.
References:
[1] Y. Wang, K.S. Chen, J. Mishler, S.C. Cho, X.C. Adroher, Appl. Energy 88 (2011) 981.
[2] Zhdanov, V. P. and Kasemo, B., Role of the field fluctuations in electrochemical reactions, Surf. Sci. 521 (2002) L655.
[3] Guidelli, R. and Schmickler, W., Recent developments in models for the interface between a metal and an aqueous solution, Electrochim. Acta.45 (2000) 2317.
[4] Fawcet, W. R. and Smagala, T. G., New developments in the theory of the diffuse double layer, Langmuir 22 (2006) 10635.
[5] Siepmann, J. I. and Sprik, M., Influence of surface topology and electrostatic potential on water/electrode systems, J. Chem. Phys. 102 (1995) 511.
Predictive Particle-Based Simulation of the Fabrication of Li-Ion Battery Electrodes
Authors: Forouzan M. Mehdi , Chien Chao-Wei , Bustamante Danilo , Lange William , Mazzeo Brian A , Wheeler Dean 
Published: February 2020

The microstructure of commercially made lithium-ion battery electrodes is not necessarily optimal for cell performance. In an attempt to optimize the performance, detailed understanding of the microstructure is necessary. Factors that influence electrode microstructure include high-level variables such as composition and porosity; as well as detailed fabrication conditions that are part of the film-making, drying, and calendering steps.
Here we report on initial efforts to model the particle-level microstructure of lithium-ion cathodes and how this relates to fabrication conditions. LAMMPS, a molecular simulation code, was adapted for these mesoscale particle simulations. In particular we simulate a cathode composed of irregular-shape active material particles using a superposition of spheres to imitate complex particle shapes and aggregates of carbon and binder. Equations of motion coupled to inter-particle forces are solved to simulate particle motion and subsequent immobilization during fabrication steps.
Both the slurry and dried film are simulated and validated by comparing to experimental results for microstructure, tortuosity, and mechanical properties like viscosity and elasticity. Initial work includes simulations of NCM cathodes. Such simulations are a first step in allowing us to predict electrode microstructure and therefore battery performance from fundamental fabrication conditions.
This work is supported by the U.S. Department of Energy through the BATT program.

Figure 1
Highly Active LiNi1-X

Mx
O2 (M = Mn, Co, Fe) Electrocatalysts for Oxygen Evolution Reaction in Alkaline Conditions
Authors: Augustyn Veronica , Turner Travis , Manthiram Arumugam 
Published: February 2020

The efficient electrocatalysis of the oxygen evolution and reduction reactions (respectively, OER and ORR) remains a serious challenge for the development of electrochemical energy conversion and storage devices such as fuel cells, electrolyzers, and metal-air batteries. In addition to the need for new non-noble metal catalysts is the need for improved understanding of their electrocatalytic mechanisms. This presentation will describe a new class of alkaline OER electrocatalysts based on layered LiNi1-x

Mx
O2 (M = Mn, Co, Fe) where the Ni content is ≥ 0.85. In this class of materials, the catalytic activity can be tuned over two orders of magnitude by engineering the bulk properties of the layered oxide. Due to the rich compositional space afforded by the O3 layered structure of LiNiO2, the M content and composition and the Li content can be varied while maintaining relatively similar surface areas. First, Fe-doped materials exhibit the highest activities, with the maximum activity for 0 ≤ Fe ≤ 0.1. The Li content can be varied during the solid-state synthesis as well as after the synthesis by chemical lithium extraction with an appropriate oxidizing agent. During the solid-state synthesis, Li deficiency introduces Ni2+ into the structure which is correlated with poor electrocatalytic activity. This indicates that Ni3+, with a single eg
orbital electron, may be important for high catalytic activity. Indeed, NiO and Li-doped NiO synthesized under similar conditions exhibit low activities. On the other hand, chemical delithiation leads to increased Ni4+ content as well as increased surface areas, resulting in an improvement in catalytic activity. Lastly, appropriate heat treatment conditions result in materials with electrocatalytic activities on par with the best bulk electrocatalysts, on the order of 178 mA/mg for a 0.4 V overpotential. In addition to the correlation of bulk properties with electrocatalytic activity, the surfaces of the materials were also characterized with XPS. Further improvements in the activity of LiNi1-x

Mx
O2 should be possible with higher surface, nanostructured materials.
(Invited) Perspectives for Design of Active and Stable Oxygen Evolution Electrocatalysts
Authors: Zeradjanin Aleksandar R. , Topalov Angel A. , Cherevko Serhiy , Mayrhofer Karl J.J. 
Published: February 2020

One of the key challenges for the large-scale application of electrochemical energy conversion, employing reactors for water electrolysis and CO2 reduction, is still relatively low energy-efficiency of the anodic oxygen evolution reaction (OER). Although, oxides are perceived to be representative class of compounds used as catalytic materials, after more than 40 years of intensive research on OER, it is still not clear what really determines activity and stability trends. At technically relevant current densities, the critical point for obtaining a conclusive picture about the electrode performance is to understand the dynamic behavior of the triple-phase boundary. Fluctuations in the magnitude of the active surface area, due to blockage of a fraction of the overall number of active sites by the gas, induces great uncertainty in kinetic analysis which is usually based on stationary electrochemical methods. Consequently, the task of the highest merit is to employ advanced analytical tools and create methodologies which allow realistic insight into dynamic behavior of the polarized electrode/electrolyte interface during the gas release. In this work, recently developed approaches for comprehensive activity/stability studies will be discussed. Namely, activity is estimated using scanning electrochemical microscopy (SECM) in a mode adjusted for local electrochemical noise measurements. A positioned microelectrode was used as a sensor in order to estimate/monitor the frequency of gas-bubble detachment from the electrode surface. Recorded potential-dependent frequency spectra are the fingerprints of temporal fluctuations at the electrode/electrolyte interface. At the same time stability analysis was conducted using a miniaturized electrochemical scanning flow cell coupled to the inductively coupled mass spectrometer (SFC-ICPMS). Obtained time-resolved potential dependent dissolution profiles were used as indication of the character of the dissolution process. In the final section of the work, based on the information gathered from SECM and SFC-ICPMS, was proposes a design of the electrode surface which could help to achieve the elusive goal of having simultaneously highly active and highly stable catalysts for the oxygen evolution reaction.

Acknowledgment. BMBF for the financial support in the framework of the project ECCO2 (Kz: 033RC1101A).
References:
1. A.R. Zeradjanin et al. ChemSusChem 5 (2012) 1905.
2. A.A. Topalov et al. Angew. Chem. Int. Ed. 51 (2012) 12613
3. A.R. Zeradjanin et al. RSC Adv. 4 (2014) 9579
4. K.J.J. Mayrhofer et al. Angew. Chem. Int. Ed. 53 (2014) 102
5. A.R. Zeradjanin et al. Int. J. Hydrogen Energ. 39 (2014) 16275
Simultaneous Detection of Dopamine and Oxygen Species Using Coated Electrodes
Authors: ALshandoudi Laila Mohammed 
Published: February 2020

The various coatings were used for simultaneous determination of dopamine and oxygen species for biological application. The conditioning waveform at bare electrode was found to give more reproducible Oxygen Reduction Reaction (ORR) amperometric response than those coatings (without condition waveform).
This work provides some examples of how the variation of surface composition can alter the electrocatalytic properties of Pt and Carbon Fiber (CF) electrodes towards the ORR and dopamine oxidation. Various types of modifications show advantages and limitation in measuring the redox species under study.
Based on these preliminary investigations, coated Pt electrode in most cases is better as a catalyst for detecting dopamine and oxygen. However, this noble metal is well known for instability for practical use in vivo. Employing Differential Pulse Voltammetry (DPV) technique, the detection of dopamine was not superior in enhancing dopamine signal, although its capability in the discrimination of the background effect and the presence of coating.
The data obtained also showed the better reproducibility of the response for the electroreduction of oxygen when applying the conditioning waveform at the bare electrode rather than use of coatings (without any conditioning waveform) at the Pt electrode. Polypyrrole and poly(phyenlene) coatings are the best two coatings for the oxidation of dopamine species and to obtain a reproducible surface for the amperometric response of oxygen.
Electrodes covalently modified with substituted diazonium salts can be used for further chemical modification. This in turn suggests the ability to tune the property of the modified electrode to be used for many applications like dopamine and other neurotransmitter determinations.
Voltammetric investigations in biological media encounter the problem of interferences. Adsorption of protein molecules is another difficulty in the measurement. For the tried coatings the electrochemically modified electrodes can be used then to test the ability to prevent protein adsorption at the electrode. The stability of the electrode is another issue which needs to be taken into account and the trials for prolonging the use of the coated electrodes are some targets that need to be achieved in further work.