bluuebunny/crossref_metadata_2025_split huggingface dataset:
Advanced Characterization of Molten Salts
Authors: Merwin Augustus , Benmore Chris , Williamson Mark A. 
Published: February 2020

Standard methods of analysis are frequently incapable of characterizing molten salts due to the high temperatures and chemically reactive nature of these systems. As a result, fundamental properties of molten salt solutions, and material interactions with them, remain unknown despite their industrial significance. The molten LiCl, LiCl-Li2O, and LiCl-Li2O-Li systems are of specific interest to the electrolytic reduction process used to treat oxide nuclear fuels prior to pyrochemical reprocessing. In this study, we employ two advanced techniques, impedance sensitive electrochemistry and synchrotron based high energy X-ray diffraction (HEXRD), to characterize molten LiCl and to demonstrate the benefits of these methods of analysis.
Impedance dependent electroanalytical chemistry was used to study the electrochemical behavior of molten LiCl-Li2O, and to investigate the processes associated with Li+ reduction from the melt. During this study, a unique behavior of the AC signal was observed to coincide with Li+ reduction. This effect has been investigated in terms of the electrochemical reversibility of the Li|Li+ redox couple, and has yielded information that could not be obtained using standard DC voltammetry techniques. The advantages of employing impendence sensitive methods of electroanalysis for the study of molten salts over typical DC voltammetry methods will be discussed.
The nature of elemental Li suspended in molten LiCl has been the subject of research for more than 50 years without yielding conclusive results. The study of molten solutions containing Li is exceptionally challenging due to the reactivity of molten Li, and as a result requires advanced methods of analysis. In attempt to circumvent these challenges, a system has been developed for containing molten salts and liquid metals during synchrotron characterization at the Advanced Photon Source (APS). By employing the APS, the system is capable of in situ characterization of molten LiCl while electrochemically forming Li in the melt. Standard methods of synchrotron analysis are incapable of characterizing molten LiCl due to the low energy state of the electrons of interest (55 eV in the case of Li). HEXRD offers a distinct advantage in this regard, as it is capable of yielding the structure factor and the corresponding pair distribution function of low energy electron states using high energy X-rays. In the current experiment, 100 KeV X-rays were propagated through an atmospheric chamber, the melt containing crucible, and a molten LiCl electrochemical cell, in order to characterize the molten solution during electrochemical analysis. This apparatus enables the study of the physical chemistry of the melt, as well as in situ characterization of material interactions with the high temperature fluid. The ability of this technique to characterize molten LiCl-Li2O-Li at 650°C will be presented along with an analysis of the chemistry of the melt itself.
Implications of Measurement Uncertainty in Battery Performance Analysis
Authors: Nagpure Shrikant C , Dufek Eric J. , Dickerson Charles C , Bewley Randy L , Walker Lee K. , Wood Sean M , Liaw Bor Yann , Tanim Tanvir 
Published: February 2020

Laboratory testing of coin cells, batteries, battery packs and modules is essential in development of durable, reliable and safe battery systems. Battery testing hardware and software have improved significantly over the past decade, but the effectiveness of the laboratory test results from advanced battery testing equipment depends on its accuracy and precision. Battery testing hardware is capable of measuring only primary parameters such as current, voltage and time during testing. Hence any uncertainty or error in measuring these primary parameters will result in loss of accuracy and precision in subsequent analyses and erroneous prediction of battery performance [1, 2].
Analysis of battery systems goes beyond the scope of the primary parameters, however, and depends largely on the derived critical secondary performance parameters such as capacity, energy, power, and Coulombic efficiency. Moreover, for advanced failure mode analysis diagnostic and prognostic tools such as differential capacity and state of charge estimation are used. The battery degradation mechanisms and failure modes can be quantified from differential capacity analysis by evaluating loss of active material, loss of lithium inventory, and change in reaction kinetics [3]. State of charge (SOC) is another critical parameter that defines the performance state of the battery. Uncertainty in SOC estimation limits battery usage during operation [4]. Combined SOC and differential capacity analyses depend on the calculation of parameters such as capacity which in turn depend on accurate and precise primary parameter measurements.
This work addresses an approach to estimate uncertainty in primary measured parameters. Equations to identify uncertainty in derived complex parameters will be discussed. A quantitative analysis of uncertainty in critical analysis and performance parameters will be presented. The results show how errors propagate from the primary measurements to the more advanced diagnostic and prognostic methods as well as the subsequent effects on performance analysis of battery systems.
References:
[1] John L. Morrison, Gary L. Hunt, Donna J. Marts, and Chester G. Motloch, “Uncertainty Study INEEL EST Laboratory Battery Testing Systems, Vol 2: Applications of Results to INEEL Testers,” INEL/EXT-01-00505, Idaho National Laboratory (2003)
[2] Barry N. Taylor and Chris E. Kuyatt, “Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results,” NIST Technical Note, 1297 (1994)
[3] Matthieu Dubarry, Arnaud Devie, and Bor Yann Liaw, “
The Value of Battery Diagnostics and Prognostics,”J. Energy Power Sources, 1, 242 (2014).
Zhe Li, Jun Huang, Bor Yann Liaw and Jianbo Zhang, “On State-of-Charge Determination for Lithium-ion Batteries,” J Power Sources, 348, 281, (2017)
(Invited) Measurement Methods to Quantify the Physico-Chemical Parameters Required for Lithium Ion Battery Performance Models
Authors: Landesfeind Johannes , Ehrl Andreas , Morasch Robert , Wall Wolfgang A. , Gasteiger Hubert A. 
Published: February 2020

Numerical simulations based on the porous electrode theory [1] are commonly used to describe and predict the rate performance of lithium ion batteries. This, however, requires that the relevant properties of the electrolyte and the porous electrode are available for a given electrolyte as a function of electrolyte composition (solvents, salt concentration) and temperature.
Unfortunately, very few of these parameter sets for typically used binary electrolytes can be found in the literature (e.g., Reference [2]), with the exception of the electrolyte conductivity, which can be determined quite easily. Therefore, over the past years, we have focused on developing methods to quantify the following parameters needed for numerical models: i) the thermodynamic factor (1+dln(f

±
)/dln(c)) [3], which is derived from the mean molar activity coefficient f

±
; ii) the effective ionic conductivity of porous electrodes by means of AC impedance spectroscopy [4]; iii) the binary diffusion coefficient, D

±
; and, iv) the lithium ion transference number, t+
[6].
In this contribution we will present the various measurement methods, compare the resulting parameters with the literature, and also present the temperature dependence of the thermodynamic and transport parameters.

References

[1] J. Newman, K. E. Thomas-Alyea, Electrochemical Systems, 3rded. (2004), Wiley-Interscience, Hoboken.
[2] L.O. Valøen, J. N. Reimers, J. Electrochem. Soc. 152(2005) A882.
[3] J. Landesfeind, A. Ehrl, M. Graf, W. A. Wall, H. A. Gasteiger, J. Electrochem. Soc. 163(2016) A1254.
[4] J. Landesfeind, J. Hattendorff, A. Ehrl, W. A. Wall, H. A. Gasteiger, J. Electrochem. Soc. 163(2016) A1373.
[5] A. Ehrl, J. Landesfeind, W. A. Wall, H. A. Gasteiger, J. Electrochem. Soc. 164(2017) A826.
[6] A. Ehrl, J. Landesfeind, W. A. Wall, H. A. Gasteiger, submitted.

Acknowledgements

We gratefully acknowledge the funding by the Bavarian Ministry of Economic Affairs and Media, Energy, and Technology for its financial support under the auspices of the EEBatt project as well as funding by the German Ministry for Education and Research in the framework of the project ExZellTUM II (funding number 03XP0081).
Characterization of Lithium Inventory in Lithium Metal Anodes during Cycling
Authors: Raj Abhishek , Park Jeung Hun , Steingart Daniel A 
Published: February 2020

A rising interest in batteries has resulted from a need for improved energy storage systems for transportation and portable electronics applications. Lithium is of particular interest as an anode due to its low redox potential and high specific capacity. However, these systems have not been practically realized due to the nonuniform plating of lithium. Many studies have modeled this formation of dendritic or mossy structures as a function of parameters such as temperature, electrolyte composition, current density and overpotentials [1]. However, the majority of these efforts have focused on the influence of these parameters on the nucleation and growth of lithium at early stages; the processes for deplating of lithium during discharge and the continued growth of dendritic structures, once formed, are poorly understood. In this work, we use commercially available primary cells as a basis for understanding the movement of lithium during cycling. Specifically, we discharge both coin and pouch cells at a range of C rates to specified states of charge (SOC). During discharge, acoustic time of flight studies are used to provide insight on how mass is transferred between layers [2]. Once the cell has been discharged to the specified SOC, electrochemical impedance spectroscopy is conducted before dismantling the cell and observing the lithium electrode using scanning electron microscopy. The same characterization methods are subsequently used for cells that have been discharged and charged for a range of cycles. Through these techniques, we track how lithium is transferred between electrodes, as well as how lithium is spatially utilized across the anode. References [1] Xu, Wu, Jiulin Wang, Fei Ding, Xilin Chen, Eduard Nasybulin, Yaohui Zhang, and Ji-Guang Zhang. 2014. “Lithium Metal Anodes for Rechargeable Batteries.” Energy & Environmental Science 7 (2). The Royal Society of Chemistry: 513–37. [2] Hsieh, A. G., S. Bhadra, B. J. Hertzberg, P. J. Gjeltema, A. Goy, J. W. Fleischer, and D. A. Steingart. 2015. “Electrochemical-Acoustic Time of Flight: In Operando Correlation of Physical Dynamics with Battery Charge and Health.” Energy & Environmental Science 8 (5): 1569–77.
(Invited) Ion Transport through the Pore Channels of Anodic Nanoporous Alumina Membranes and Graphite Composite Electrodes
Authors: Abe Takeshi , Fukutsuka Tomokazu , Miyazaki Kohei , Miyahara Yuto 
Published: February 2020

Present LIBs for EV-use possess large power densities by the sacrifice of energy densities in order to shorten the charging time. In the practical LIBs for portable devices, dense and thick composite electrodes are used. In this case, the ion transport of electrolyte solution through the pores in the composite electrodes becomes a slow process. In order to enhance the energy densities with remaining high power densities, the ion transport rate should be increased for the dense and thick composite electrodes. Unfortunately, to develop dense and thick electrodes with high power densities, fundamental understanding of the ion transport in composite electrodes has not been clear. In this study, ion transportation behavior was investigated with ac impedance spectroscopy.
To focus on the impedance of ion transportation of electrolyte through the pores in composite electrode, we prepared anodic aluminum membranes with homogeneous macro- and meso- pores. In addition, graphite composite electrodes were also used. As a result, we obtained semi-circles, and this semi-circle was assigned to the ion transport process through the graphite composite electrode. The detail analysis will be presented at the meeting.
(Invited) High Lithium Sulfide-Loading Electrode for Practical Li/S Cells
Authors: Cairns Elton J. , Sun Dan 
Published: February 2020

The development of the Li-ion battery (LIB) has led to a portable electronics revolution during last couple of decades, however, the traditional LIB seems to be insufficient for practical application in some emerging markets due to the limited specific energy of the cell. For mass market conversion to electric vehicles, high specific energy (> 300 Wh kg-1) rechargeable battery systems of low-cost for energy storage are required. Among all alternatives, the lithium/sulfur cell has been considered most promising due to its low cost, high abundance, ultrahigh theoretical specific energy (2,566 Wh kg-1) and theoretical energy density (4,260 Wh L-1) which far exceed those of conventional lithium-ion cells. Nevertheless, after extensive study of both sulfur cathodes and lithium sulfide cathodes, neither of these technologies has been commercialized due to poor long-term cycle life and low demonstrated specific energy of lithium/sulfur cells. Practical applications require high sulfur loading electrodes together with the lowest “dead weight” possible in the cell while maintaining good performance. This is quite challenging because commercial current collectors have mechanical limitations in electrode loading and sulfur utiliation. Due to the insulating nature of S and Li2S, the addition of a significant amount of a conductive additive into the high loading electrodes is required and introduces more surface area, and thus more electrolyte is needed which further leads to more dead weight. Recently, lithium sulfide was proposed to be a more desirable electrode material because it permits the cell to be assembled in discharged state and avoids problems associated with volume expansion of sulfur during discharge. Disadvantages of lithium sulfide include challenging issues due to its sensitivity toward moisture and solubility in many organic solvents. In order to achieve high specific energy, we have developed a novel Li2S/KB@Cf electrode (Li2S content: 74 %,) using a robust 3-dimensional (3-D) current collector with a high Li2S loading up to 11.29 mg cm-2 (S loading: 7.85 mg cm-2), which can deliver an areal capacity of 7 mAh cm-2 after 50 cycles with an Electrolyte/Sulfur ratio of 5.5 (see Fig. 1). We will present our recent progress in high S loading cells and more detailed information about active material development, electrode composition and modifications of the electrolyte and cell configuration.

Figure 1
(Invited) Pulsed Electrodeposition of Refractory Metals in Ionic Liquids
Authors: Ispas Adriana , Endrikat Anna , Engemann Thomas , Peipmann Ralf , Bund Andreas 
Published: February 2020

This paper presents recent results from authors’ lab on the pulsed electrodeposition of refractory metals from ionic liquids (ILs). Special focus will be given to the refractory metals tantalum and niobium (Fig. 1) as they are promising candidates for surface finishings with extremely high corrosion resistance.
We could show that by varying the pulse plating parameters (such as the potential of the on pulse, as well as the frequency and the duty cycle) one can optimize the morphology of the deposits. Thus, experimental conditions have been identified with which uniform and crack-free deposits can be obtained. Due to the high viscosity and low conductivity of the ionic liquids, the useful frequency range for pulse plating is somewhat different from one knows from aqueous electrolytes. Moreover, the effect of the temperature (from 25°C till 170°C) on the properties of the deposits has also been investigated and will be discussed in this paper.
Fig. 1. Nb layer electrodeposited on Ti substrates from 0.5M NbF5 in 1-butyl-1-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)amide at RT; Deposition conditions: 1 min @-1V; 1 min @ -2.5V, sequence repeated for 2500x.

Figure 1
(Invited) Low Wear Index Chromium Coatings Electroplated from a Functional Reach-Compliant Trivalent Chromium Chemistry
Authors: Hall Timothy D , Taylor E. J. , Inman Maria , Snyder Stephen , Xu Jing , Radhakrishnan Rajeswaran 
Published: February 2020

Faraday Technology Inc. is a research, development and engineering firm developing electrochemical innovations based has pulse/pulse reverse electrolytic principles [1]. One of Faraday’s current activities is directed towards the development of an innovative REACH-compliant plating process for deposition of functional chrome coatings, based on replacement of the conventional hexavalent chromium plating chemistry with a non-toxic trivalent chromium chemistry. Hexavalent chromium plating has been used for many decades to produce hard, durable coatings with excellent wear and corrosion resistance properties. However, hexavalent chromium has come under increasing scrutiny due to the toxic nature of the bath, effects on the environment, and workers’ health. Faraday has demonstrated that the chrome coatings prepared using the FARADAYIC(R) Process in a trivalent chromium chemistry have equivalent functional properties to chrome coatings produced with a hexavalent chromium bath. The data demonstrates equivalent or superior: 1) plating rate, 2) Knoop hardness, 3) current efficiency, 4) hydrogen embrittlement behavior, 5) adhesion, 6) corrosion resistance, 7) porosity, 8) thickness, 9) Taber Abrasion, Ball on Flat Reciprocating and Dithering wear resistance, with no hexavalent chromium formation in the bath.
This paper will discuss the 2013 EPA Green Chemistry Challenge Award winning work on the development of a REACH-compliant plating process for wear resistant, functional coatings from a single, simple-to-control trivalent-based electrolyte. Specifically, this paper will discuss electrochemical deposition approaches to improve (decrease) the wear index of the chrome coating, to meet the performance from conventional chrome coating processes.

Acknowledgements: This study is supported by the US Army (W911NF-11-2-0014) and private sources.
[1] E. J. Taylor “Adventures in Pulse/Pulse Reverse Electrolytic Processes: Explorations and Applications in Surface Finishing” J. Applied Surface Finsihing,
3(4), 178-189 (2008).
A High Performing Zero Gap Alkaline Electrolyzer
Authors: Masel Rich , Liu Zengcai , Yang Hongzhou , Sajjad Syed D. , Gao Yan , Kaczur Jerry J. 
Published: February 2020

Water electrolyzers are being developed as a way of storing renewable energy, as a way to produce hydrogen for fuel cell automobiles, and as a route to renewable fuels and chemicals. In this paper, we demonstrate alkaline water electrolyzers at 60 °C with iron/nickel/cobalt catalysts that show 1 A/cm² at a 1.9 V cell potential The performance is stable for 2000 hours, showing only 3-5 µV/hr degradation. Key to the findings is the development of new Sustainion™ alkaline exchange membranes that show high conductivity and stability in 1 M KOH.
The paper will discuss new developments that improve the response of the electrolyzers to process upsets, and to improve the on-off performance of the devices.
(Invited) Speciation during Wet Etching of III-V Semiconductors
Authors: Hinckley Adam , Foster Elijah , Corley Tim , Muscat Anthony J. 
Published: February 2020

III-V materials could be a substitute for Si and Ge in semiconductor device development because they possess higher carrier mobilities. Wet chemical cleaning and patterning of III-Vs produces soluble species that can remain in the liquid phase, precipitate as solids and remain on the surface, or evaporate as gases. Because etching products contain elements such as In, As, and Sb, they can pose health risks during industrial wafer processing. To better understand the products generated from III-V etching, vapor-phase arsenic levels were measured above wet etching solutions commonly used to clean or etch GaAs. A differentially pumped mass spectrometer system was used to sample the vapor above the etching solution at atmospheric pressure. The mass fragments detected as a function of time were used to determine the arsenic species present and estimate concentrations.
Mass fragments corresponding to AsO+, AsH2
+ and AsH3
+ were detected above GaAs immersed in aqueous HF at room temperature. The partial pressure of the etching products was on the order of 0.1 mTorr. Using N2as a reference, the total gas-phase arsenic concentration above 0.6 M and 28.9 M aqueous HF was approximately 1 ppm and 2 ppm, respectively. These concentrations are about 400 times the Permissible Exposure Limit (PEL) set by the Occupational and Safety Health Administration (OSHA) for inorganic arsenic species. Gallium was not detected in the vapor phase. Inductively-coupled plasma mass spectrometry (ICP-MS) was used to measure etching species in solution. The Ga concentration was higher than that of As by a factor of 100. Combining these techniques, a mass balance was closed between liquid and vapor phase arsenic species within approximately 1 nmol.
Etching GaAs in aqueous SC-2 (HCl and H2O2 in DI water) solutions produced AsO+, AsH2
+ and AsH3
+ in the vapor phase. The total gas-phase arsenic concentration above SC-2 was 5 nmol (about 4 mg/m3) regardless of the reactant concentration. The concentration of AsO+ increased by a factor of 2 when vapor was collected for 30 min prior to measurement. One interpretation is that etching produces AsCl3 which hydrolyzes readily in the liquid or gas phase. To test this hypothesis, arsenic species were examined as a function of time above a GaAs coupon in partially aqueous SC-2 (HCl:H2O2:H2O:CH3OH, 4:3:12:250 v/v). Figure 1 shows mass spectra after pulses of product gases were sampled above the solution. The total gas-phase arsenic concentration increased by a factor of 3.3 when GaAs was etched in partially aqueous SC-2. The primary arsenic fragment was As+, and Cl+ increased by a factor of 5 with respect to GaAs etched in aqueous SC-2. The comparison of As and Cl fragments detected to known cracking patterns supports the hypothesis that AsCl3is produced during etching of GaAs and is hydrolyzed. Speciation of etching products will be compared to OSHA PEL standards for inorganic arsenic species to identify potential hazards present in III-V manufacturing.

Figure 1