bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface Chemistry Mechanism of Ultra-Low Interfacial Resistance in the Solid-State Electrolyte Li7La3Zr2O12
Authors: Sharafi Asma , Kazyak Eric , Davis Andrew L. , Yu Seungho , Thompson Travis , Siegel Donald J , Dasgupta Neil P. , Sakamoto Jeff 
Published: February 2020

The garnet-type solid-state electrolyte, based on the nominal formula Li7La3Zr2O12 (LLZO), is unique in that it is a fast Li-ion conductor, exhibits sufficient mechanical properties, and is also chemically and electrochemically stable against metallic Li. Despite these promising attributes, additional challenges must be overcome before solid-state batteries based on LLZO are viable. Demonstrating low Li–LLZO interfacial resistance (R
Li–LLZO) is a critical milestone along the path to commercialization. While several studies have characterized R
Li–LLZO, nearly all report values significantly higher than conventional LIBs employing liquid electrolytes. Thus, strategies to reduce R
Li–LLZO to values comparable to, or lower than, LIBs are needed [1].
In this study, the impact of surface chemistry on the interfacial resistance between the LLZO solid-state electrolyte and a metallic Li electrode is revealed [1]. Control of surface chemistry allows the interfacial resistance to be reduced to 2 Ω cm2, lower than that of liquid electrolytes, without the need for interlayer coatings. A mechanistic understanding of the origins of ultra-low resistance is provided by quantitatively evaluating the linkages between interfacial chemistry, Li wettability, and electrochemical phenomena. A combination of Li contact angle measurements, X-ray photoelectron spectroscopy (XPS), first-principles calculations, and impedance spectroscopy demonstrates that the presence of common LLZO surface contaminants, Li2CO3 and LiOH, result in poor wettability by Li and high interfacial resistance. On the basis of this mechanism, a simple procedure for removing these surface layers is demonstrated, which results in a dramatic increase in Li wetting and the elimination of nearly all interfacial resistance. The low interfacial resistance is maintained over one-hundred cycles and suggests a straightforward pathway to achieving high energy and power density solid-state batteries.
[1] A. Sharafi, E. Kazyak, A. L. Davis, S. Yu, T Thompson, D. J. Siegel, N. P. Dasgupta, J. Sakamoto, Chem. Mater.
29, 7961(2017)
Constructing Sulfone Based Electrolyte System for High Energy Density Li-S Batteries
Authors: Shin Woochul , Stickle William F. , Ji Xiulei 
Published: February 2020

Development of electric vehicle has led ever increasing demand of high energy density lithium ion batteries such as Li-sulfur, and Li-oxygen batteries. In this regard, lithium metal received huge attention as an anode due to the high specific capacity (3,860mAh/g) and the lowest electrochemical potential (-3.04V versus standard hydrogen electrode). However, nature of lithium metal is giving rise to safety concerns including uncontrollable dendrite growth, chemical reaction with organic electrolyte, and volume change while cycling, which also result in poor cycling performance. Due to those reasons, broader use of lithium metal as an anode was hindered in the commercialized field.
Here, we introduce Ethyl Methyl Sulfone (EMS) as a co-solvent in a typical electrolyte system, 1,3-Dioxolane (DOL) and Dimethyl ether (DME) to tackle those challenges. Adding EMS into the DOL/DME shows outstanding performance of suppressing dendrite growth as well as retaining good cycling stability proven by Li|Li symmetric cells and Li|Cu cells respectively. Scanning Electron Microscopy (SEM) showed non-dendritic surface of lithium metal unlike needle-like dendrite surface of control sample (DOL/DME only). Energy Dispersive X-ray Spectroscopy (EDX) also showed well-dispersed fluorine and sulfur elements and XPS analysis was conducted to prove the existence of Solid Electrolyte Interface (SEI) composed of lithium-sulfur-carbon(oxygen) mixed with lithium fluoride. We suggest sulfur in EMS act as crosslinking agents to form robust SEI that holds volume expansion, dendrite growth, and continuous lithium consumption which leads higher C.E. than DOL/DME system. Lastly, lithium metal was paired with sulfur cathode in coin cells to show better cycling performance, which can be further used in Li-S environments.
NMR Diffusion Study of Ionic Liquids and Ionogels for Use in Lithium Ion Batteries
Authors: Jayakody Nishani Kanchana , Gobet Mallory , Greenbaum Steven , Ashby David , Dunn Bruce S. 
Published: February 2020

Solid-state electrolytes have been explored increasingly for use in Li+ batteries on account of their ability to address the safety issues, packaging constraints, and volumetric design concerns associated with liquid electrolytes. Recently, ionogels, pseudo-solid-state electrolytes consisting of an ionic liquid electrolyte confined in a mesoporous inorganic matrix, have attracted interest because of their high ionic conductivity, stability, and solution processability. Due to the complexity of the trapped liquid, the nature of the ion interaction and movement is not well established. Understanding how the ions behave inside the matrix is paramount for increasing the ionic conductivity and Li+ transference number. The literature for these characteristics is lacking in several key areas including, but not limited to, variations in the electrolyte’s Li+ concentration, the choice of silica precursors, and diffusion under different conditions.
The ionogel matrix was synthesized using a non-aqueous organic acid catalyzed sol-gel process to form a nanoporous silica matrix around an ionic liquid, BMIM TFSI with variable amounts of LiTFSI added, thus confining the electrolyte. The choice of silica precursors and use of an organic acid allows for a crack free monolith to form under rapid gelation conditions. The silica component maintains a highly porous network with surface areas up to 1300 m2/g and an average pore size of 20nm as measured through N2 adsorption. The ionic liquid (IL) electrolyte component constitutes 75 vol% of the ionogel. Thermal gravimetric analysis shows that the ionogel is thermally stable to 400 oC. Due to the interconnected porosity and large percentage of liquid, conductivities of ̴10-3 S/cm were measured at room temperature for the prepared monoliths using electrochemical impedance spectroscopy (EIS).
The degree to which each ion contributes to the total conductivity can be determined by combining the conductivity measurements with self-diffusion measurements obtained by pulsed field gradient nuclear magnetic resonance (PFG NMR) methods. Furthermore the presence of ion pairing or aggregation can be ascertained by direct comparison between the NMR-predicted and EIS-measured conductivity.
In this work, the PFG NMR stimulated echo sequence was used to measure the self-diffusion coefficients of the IL cation, Li+, and anion via 1H, 7Li and 19F, respectively, in the IL and ionogel with a concentration of 1M LiTFSI, at variable temperature covering the 0o – 100oC range. Two main confinement effects of all mobile ions in the ionogel are observed (i) a reduction in self-diffusion values of all ions compared to the pure IL; (ii) the presence of a relatively immobile fraction of the ions. Interestingly the effective Li transference numbers defined as D(Li)/[D(Li) + D(BMIM) + D(TFSI)] in the liquid electrolyte and the and ionogel are comparable, with a value of approximately 0.20.
Study on the Interface between NCM Layered Cathodes and Sulfide-Based Solid Electrolytes in All-Solid-State Batteries
Authors: Yun Bin-Na , Kim Hyoungchul , Jung Hun-Gi 
Published: February 2020

Since the lithium-ion secondary batteries (LIBs) based on the LiCoO2 cathode materials, carbon based anode materials and organic liquid electrolyte have been commercialized, LIBs have been applied as power source for electric or hybrid vehicles beyond small IT applications. [1,2] As used in the large-scale energy storage devices, the safety of LIBs has given rise to more important issue. Therefore, the all-solid-state-batteries (ASSBs) with non-flammable inorganic solid electrolyte are one of the promising candidates.[3,4] Among the solid electrolyte materials, the sulfide-based solid electrolytes are widely used due to higher Li-ion conductivity and their soft property. Nevertheless, the ASSBs have been yet difficult to operate with the long cycle life and high current density despite the use of high Li-ion conducting solid electrolyte owing to the interfacial resistance and insufficient electrochemically active area. [5,6] Therefore, it is important to understand the interfacial characterization of solid-solid interface, especially the cathode and solid electrolyte in the composite cathode of ASSBs. Generally, the cathode materials and sulfide-based solid electrolytes have shown the large interfacial resistance from the space-charge layer and thus, as an effective approach to improve the electrochemical performance of ASSBs, the interfacial modifications for the cathode material by coating of LiNbO3, Li4Ti5O12, LiTaO3, and Li2O-SiO2 have been reported in previous studies. [5-7]

Herein, the detailed microscopic observation and structural analysis for the interface between Li(Ni0.6Co0.2Mn0.2)O2 (NCM622) layered cathode materials and sulfide-based solid electrolyte are carried out and the comparison with pristine NCM622 and LiNbO3-coated NCM622 is also depicted. For this study, transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) analysis have been mainly used. For further investigations, the electrochemical impedance spectroscopy and charge-discharge performance of the all-solid-state batteries using pristine and LiNbO3-coated NCM622 were demonstrated.

References

[1] J.B. GoodenoughAuthor Vitae, K.S. ParkAuthor VitaeAuthor VitaeAuthor VitaeAuthor Vitae, J. Am. Chem. Soc., 4 (2013) 1167-1176.
[2] J.-Y. Hwang, S.-T. Myung, Y. K. Sun, Chem. Soc. Rev, 46 (2017) 3529−3614.
[3] Y. Ito, M. Otoyama, A. Hayashi, T. Ohtomo, M. Tatsumisago, Journal of Power Sources, 360 (2017) 328-335.
[4] N. Kamaya, K.Homma, Y.Yamakawa, M.Hirayama, R. Kanno. M. Yonemura, T. Kamiyama, Y. Kato, S. Hama, K. Kawamoto, A. Mitsui, Nat. Mater., 10 (2011), 628−686.
[5] N. Ohta, K. Takada, I. Sakaguchi, L. Zhang, R. Ma, k. Fukuda, M. Osada, T. Sasaki, Electrochem. Commun., 9 (2007), 1486-1490.
[6] Y. Seino, T. Ota, K. Takada, Journal of Power Sources, 196 (2011) 6488-6492.
[7] A. Sakuda, H. Kitaura, A. Hayashi, K. Tadanaga, M. Tatsumisago, Electrochem. Solid-state Lett. 11 (2007) A1-A3
Effects of Electrolyte Volume and Salt Concentration on SEI Stability and Cycling Performance of Lithium Metal Anodes
Authors: Wood Sean M. , Nagpure Shrikant C. , Dufek Eric J. , Sazhin Sergiy V. 
Published: February 2020

In order to nearly triple the driving range of electric vehicles (EV), the US Department of Energy has set a goal of achieving an energy density of 500 Wh kg-1 in EV batteries, and the use of a lithium metal anode is essential to reaching this goal.(1) A key consideration in reducing the weight (and thereby increasing the energy density) of a lithium metal battery is its electrolyte, with the volume of electrolyte used and its salt concentration both affecting the overall battery weight. Unlike with the currently-used graphite anode, the highly reactive surface of a lithium anode varies widely from cycle to cycle, which irreversibly consumes the finite amount of electrolyte and causes lithium metal to suffer from low Coulombic efficiency. To account for Coulombic inefficiency caused by electrolyte depletion, many researchers "flood" their cells with electrolyte to prolong cycle life. However, commercial batteries will require smaller amounts of electrolyte in order to achieve weight and energy density goals.
Additionally, the components that make up the solid electrolyte interphase (SEI) layer on the surface of the lithium metal are soluble in the electrolyte to varying degrees. As the more soluble components selectively dissolve into the electrolyte, reparative SEI grows in its place. During non-uniform lithium plating, new SEI also forms over the freshly-exposed surface area. Both of these processes consume more of the limited electrolyte. Factors such as the volume of electrolyte used and its salt concentration affect the stability of the SEI against dissolution while also altering the composition of the SEI that forms, which can have further impacts on cell performance.
Here, three electrochemically-measurable factors are used to examine the stability of the SEI: formation rate (the rate at which the SEI forms or repairs itself each cycle), degradation rate (the rate at which the SEI dissolves or degrades during rest periods), and formation capacity (the total amount of charge dedicated to forming a stable SEI). Each of these factors will affect the consumption of electrolyte and ultimately dictate the amount of excess electrolyte needed to account for these losses.
Three electrolyte volumes and three salt concentrations were chosen to examine the impact that these parameters have on SEI stability and Coulombic efficiency in the standard 3:7 ethylene carbonate/ethyl methyl carbonate with 2 % vinylene carbonate electrolyte with LiPF6 salt. Higher volumes of electrolyte resulted in increased SEI formation rates and dissolution rates. Differences in these factors at low and high salt concentrations were found to result from a change in the type of SEI that formed.

References

Battery500 Consortium to Spark EV Innovations: Pacific Northwest National Laboratory-led, 5-year $50M effort seeks to almost triple energy stored in electric car batteries, in Office of Technology Transitions Energy.gov (2016).
Investigation of Pd and Pd-CeO2 Based Carbon-Supported Electrocatalysts for the Electrooxidation of Borohydride in Direct Borohydride Fuel Cell
Authors: Lafforgue Clémence , Chatenet Marian , Atkinson Robert W. , Swider-Lyons Karen , Miller Hamish , Dekel Dario R. 
Published: February 2020

Direct borohydride fuel cells (DBFC) are considered high-energy density generators. The ideal case for the anodic reaction of a DBFC is the direct and complete borohydride oxidation reaction (BOR) that releases 8 electrons. However, the BOR is a very complex reaction that involves numerous intermediate species and suffers from competition with the heterogeneous hydrolysis of BH4
- that leads to molecular hydrogen, making full utilization of the fuel challenging [1]. Despite many studies of the BOR on several electrocatalysts (especially Au and Pt), this reaction is still poorly understood on most practical electrocatalysts and in relevant conditions to DBFC operation, and no ideal electrocatalyst fulfilling both high activity and high faradaic efficiency at low potential has been isolated, yet.
In this study, the BOR is investigated on Pd-based carbon-supported electrocatalysts. A set of four Pd/C electrocatalysts have been synthesized using Vulcan XC72 as substrate and loaded at 22, 33, 44 and 53 wt% Pd. These materials have been thoroughly characterized in terms of BOR activity in a rotating disk electrode setup. The experiments were performed for three NaBH4 concentrations (5, 50 and 500 mM) at 60°C. The electrochemical characterizations of Figure 1 (A) reveal that the onset potential (E
i=0) (see Figure 1 (B)) is lower than 0 V vs. RHE on all the Pd electrocatalysts, meaning that BH4
- anions can be valorized directly, albeit with slow kinetics. In contrast, Pt/C first decomposes BH4
- and utilizes hydrogen species, above 0 V vs. RHE. However, the kinetic is very slow. Similar experiments have been performed with advanced Pd electrocatalysts with a composite support made of Vulcan XC72 carbon and cerium oxide, which enhance hydrogen oxidation reaction (HOR) kinetics in alkaline media [2].

Figure 1
Sensitizing the Photocatalytic Ability of Dawson-Wells Polyoxometalates in Solution and Thin Films
Authors: Keyes Tia E 
Published: February 2020

Heteropolyoxomolybdate anions exhibit rich redox and photochemistry enabled by the capacity of polyoxomolybdate to act as both electron and proton relays. They are widely investigated for application across domains involving photooxidation and photocatalysis. A key limitation though is that polyoxometallates such as [S2M18O62]4-, where M is W or Mo, are not signifantly activated by visible light.
This presentation describes investigations into the sensitization of Dawson polyoxometallates photochemistry [S2Mo18O62]4- and [S2W18O62]4- by ruthenium(II)polypyridine complexes in solution and at modified electrodes. Electrostatically associated supramolecular structures comprising of ruthenium polypyridyl cations and polyoxoanions can be readily isolated as charge neutral adducts by combining the cation and anion in solution. For [Ru(bpy)3]2+ with [S2Mo18O62]4- or [S2W18O62]4-
the polyoxometallate adducts are remarkably photostable. And [Ru(bpy)3]2+ the resulting clusters sensitises the very efficient photooxidation of organic substrates such as DMF and benzylalcohol by the polyoxometalates under visible irradiation, between 355 and 490 nm.. Resonance Raman spectroscopy was used to identify a charge transfer transition between Ru and polyoxometallate which suggests significant electronic communication in these cluster complex. Exploiting resonance Raman spectroscopy to identify the presence of the CT transition we took a combinatorial approach to identifying potentially sensitized Ru(II)-POM pairs and assemble the resulting pairs into layer by layer electrostatic assemblies at electrodes. The photoelectrochemical response of these systems, with a range of organic donors, including persistent pollutants diclofenac and ibuprofen is described.

References

Nigel Fay, Victoria M. Hultgren, Anthony G. Wedd, Tia E. Keyes, Deirdre Leane, Alan M. Bond, Dalton Trans, 2006, 4218 - 4227.

Visible Light Sensitized Photocurrent Generation from Electrostatically Assembled Thin Films of [Ru(bpy)3]2+ and the polyoxometalate [W18O54(SO4)2]4-; Optimizing Performance in a low electrolyte media, James J Walsh; Jie Zhu; Alan M Bond; Robert J Forster, Tia E Keyes, 2013, Journal of Electroanal. Chem., 2013, 706, 93-101

Hybrid Polyoxometalate Materials for Photo(electro-) chemical Applications., J. Walsh, A.M. Bond, R.J. Forster, T.E. Keyes, Coord. Chem Rev., Volume 306, Part 1, 1 January 2016, Pages 217–234

Figure 1
Field-Driven Odor Mitigation in Sanitation Facilities
Authors: Vasquez Mariana Madelen , Ngaboyamahina Edgard , De March Claire A , Do Matthew , Matsunami Hiroaki , Glass Jeffrey T. 
Published: February 2020

There is an urgent need to increase access to appropriate sanitation of human waste in developing countries. However, malodor nuisance is a major risk factor in the adoption of effective sanitation technologies. Foul-smelling sanitation facilities encourage people to practice open defecation in developing countries. Our work focuses on the mitigation of the most common and prevalent odorant molecules in human waste. These molecules consist mainly of carbon backbone endings with functional groups such as aldehydes, alcohols, or ketones. The odorant perception of these molecules can be changed to more pleasant smells by simply applying an electrical signal to the offending liquid/gas source.
We propose to demonstrate the capability to modulate malodor and generate a pleasant olfactory perception. This is achieved simply by applying an electrical signal to the offending liquid/gas source to induce an electrochemical reaction. Results suggest that butyric acid, which has a rancid smell and is used as a case study, can be selectively modified to lead to a more pleasant odorous composition, thanks in part to the production of butanal, a molecule with a fruity-strawberry like smell.
(Keynote) Modification of the Electrocatalyst Surface Composition By the Electrode Potential and the Substantial Resulting Effects on the Cell Characteristic
Authors: Gottesfeld Shimshon 
Published: February 2020

This talk addresses a fundamental aspect of electrocatalysis: the dependence of the rate of the electrocatalytic process on electrode potential. Discussions with Ratko Adzic related to this subject, starting back in the early 1990’s, are appreciatively recognized.
In a complete description of the dependence of the rate of an electrocatalytic process on electrode potential, the effect of the potential has to include two components: acceleration of the electrode reaction by lowering the activation energy of any step involving electronic charge transfer and, modification of the composition of the catalyst/electrolyte interface by the change in electrode potential. The latter effect has only rarely been included rigorously in quantitative descriptions of the rate dependence on electrode potential, thereby missing in the description an important factor determining the dependence of the rate on overpotential and , consequently, determining the power output and conversion efficiency observed in a fuel cell or electrolyzer given some combination of electrocatalyst and electrolyte.
This talk will cover examples of ORR , OER and HOR processes taking place at electrocatalysts which undergo significant changes in surface composition with change of the potential within the window of relevance to fuel cells or water electrolyzers. The examples cover several types of effects on the rate of the faradaic process as result of the dependence of the interfacial composition on overpotential, including:
* rate acceleration by potential-induced generation of active surface sites
* rate decay by potential-induced deactivation of surface sites
* rate effects by potential-induced electrolyte layer formation
Complete quantitative description of these effects in mathematical form, is, in many cases, not straightforward. Nevertheless, recognition of such effects in the general expression for the rate of the electrocatalytic process can and should be reflected by a pre-exponential factor which is potential dependent [1,2]. Assuming a potential independent pre-exponential factor, as typically done, results in misinterpretation of fundamental aspects of the kinetics of electrocatalytic process, for example the reason for commonly observed increase in "Tafel slope" with the increase in overpotential.
Finally, the argument made frequently that electrocatalytic processes can be fully understood using a single “descriptor”, e.g., a M-O or M-H bond strength (where M stands for an active metal surface site) , does not recognize the change of the number of active M sites with overpotential as result of a potential-induced surface modification process. This dependence of the number of active sites on potential has to be covered by , at least, a second “descriptor” , for a full description of the electrocatalytic process.
References:
1. S.Gottesfeld, ECS Trans. 2014 61(31): 1-13

2. S.Gottesfeld, ECS Trans. 2015 66(29): 13-30