bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface Sensitivity of Fluoroethylene Carbonate Breakdown on Lithium Silicide Surfaces
Authors: Sprowl Lynza H. , Árnadóttir Líney , Chan Maria K. Y. 
Published: February 2020

Silicon anodes are a promising material for lithium ion batteries due to their large theoretical capacity for storing lithium. When the battery is charging, the anode works by alloying lithium ions with the silicon anode where the lithium ions are reduced. In addition to the lithium ions being reduced, unwanted side reduction reactions of the electrolyte also occur. When the electrolyte reductively decomposes at the anode surface, a solid-electrolyte interphase (SEI) is formed. Fluoroethylene carbonate (FEC) is added to the electrolyte to make a more robust SEI which prevents further electrolyte decomposition. From FEC reductive decomposition, the primary reduction products are CO2, CH2CHO, and F-. While the decomposition products have been discovered, the lowest energy surface facet which promotes the breakdown of FEC into those products is still unknown.
Here FEC and its reduction products are being studied on different lithium silicide surfaces using density functional theory. The lithium silicide phases under consideration are the crystalline LiSi phase with a low lithium concentration and the crystalline Li15Si4 phase with a higher lithium concentration. All unique low index surface facets are considered for each lithium silicide phase. The interactions of FEC and its dissociation products are analyzed on the different anode surface facets to determine the surface sensitivity of FEC breakdown. From the binding energies of the FEC reactant and the CO2, CH2CHO, and F- products on the lithium silicide surface facets, FEC dissociation reaction energies are calculated. The facet on which SEI formation begins to form is determined from the reaction energies for both the low and high concentration lithium silicide anodes.

This material is based upon work supported by the U.

S. Department of Energy,

Office of Science, Office of Workforce Development for Teachers and Scientists,

Office of Science Graduate Student Research (SCGSR) program. The SCGSR program is administered by the Oak Ridge Institute for Science and Education (ORISE) for the DOE. ORISE is managed by ORAU under contract number DE-SC0014664.

Use of the Center for Nanoscale Materials, an Office of Science user facility, is

supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under

contract number

DE-AC02-06CH11357.
Polysulfide Trapping Agent (PTA) Coated Directly Doped Sulfur Architectures (DDSA) – New Platforms for High Capacity Li – S Batteries
Authors: Murugavel Shanthi Pavithra , Jampani Prashanth , Gattu Bharat , Kumta Prashant N 
Published: February 2020

Increasing demands for high energy and high power storage systems for use in electric vehicles and electronic devices has made it imperative to develop high performance rechargeable batteries. This stringent need has attracted widespread attention worldwide. Lithium – sulfur (Li – S) batteries has been consequently, extensively studied recently as a potential rechargeable electrochemical power sources due to its high theoretical capacity (1672 Ah kg−1 sulfur)1 and high energy density (2500 Wh kg−1 sulfur)2
based on the complete reduction of elemental sulfur to form the end product of lithium sulfide (Li2S).
However, commercialization pathway for Li – S batteries is still fraught with high self – discharge and the short cycle life problems of the Li – S rechargeable system. These limitations are largely related to the poor ionic and electronic conductivity of elemental sulfur3, formation of a series of sulfur reduction intermediates during discharge (Li2Sx, x > 2)4
,
5 that are highly soluble in organic electrolyte and the high reactivity of the dissolved polysulfides with the Li anode4.
Several approaches including the use of a conductive additive6, encasing sulfur into conductive porous host materials7 and replacing the organic electrolyte with a polymer electrolyte8 has been shown to improve the performance by improving the ionic conductivity of sulfur and reducing polysulfide dissolution by avoiding direct contact with the liquid electrolyte. However, despite these advances, complete prevention of polysulfide dissolution has not yet been accomplished due to lack of fundamental understanding about the mechanism of polysulfide dissolution.
In this work, directly doped sulfur architectures (DDSA) with sulfur loadings greater than 16mg/cm2 were created using simple electrochemical techniques. The cathodes were studied chemically and electrochemically to understand the mechanism of polysulfide dissolution in these structures. The DDSA electrodes are then coated with a polysulfide trapping agent (PTA) to chemically prevent the dissolution of polysulfide species. These PTA coated DDSA showed a high initial capacity of 1305 mAhg-1 with stable performance of 1208 mAhg-1 for over 30 cycles (Figure 1). Mechanism of polysulfide dissolution by PTA will be presented and discussed.

Figure 1
Long-Cycling Ferrocene/MV Aqueous Organic Redox Flow Battery (AORFB)
Authors: Hu Bo , DeBruler Camden , Liu Tianbiao 
Published: February 2020

Redox flow batteries (RFBs) are a viable technology to store renewable energy in the form of electricity that can be supplied to electricity grids. However, widespread implementation of traditional RFBs, such as vanadium and Zn-Br2 RFBs, is limited due to a number of challenges related to materials, including low abundance and high costs of redox-active metals, expensive separators, and corrosive and hazardous electrolytes. To address these challenges, we demonstrate an aqueous organic redox flow battery (AORFB), named FcNCl/MV AORFB,1 featuring a high theoretical energy density, 45.5 Wh/L, the highest value known for AORFBs. The battery is built from earth abundant elements (C, H, N, and Fe), specifically consisting of a newly designed organic catholyte based on a highly water soluble ferrocene compound, (ferrocenylmethyl)trimethylammonium chloride(FcNCl), a methyl viologen anolyte which was studied in our previous work,2 non-flammableand non-corrosive NaCl supporting electrolyte, and low cost anion exchange membrane. This is the first application of a water-soluble ferrocene compound in aqueous RFBs. The batteries exhibit extraordinary electrochemical performances, 700 cycles with 99.99% capacity retention per cylce and 65% energy efficiency at 60 mA/cm2, and delivered power density up to 125 mW/cm2. The presented AORFB technology underlines great promise of soluble redox-active organic molecules for green energy storage.
Reference
1. Hu, B.; DeBruler, C.; Rhodes, Z.; Liu, T. L., J. Am. Chem. Soc.,
2017, 139, 1207.
2. Liu, T. B.; Wei, X. L.; Nie, Z. M.; Sprenkle, V.; Wang, W., Adv. Energy. Mater.,
2016,
6, 1501449.
Direct Electrochemical Compression of Hydrogen and Oxygen Via PEM Water Electrolysis
Authors: Ayers Katherine E , Dalton Luke , Parker Michael 
Published: February 2020

One of the biggest challenges in applying hydrogen to energy storage and vehicle fueling applications is to efficiently store the hydrogen in a small volume with high reliability equipment. High pressure hydrogen applications that are used at a high duty cycle, including vehicle fueling demonstrations, repeatedly show that mechanical compression is one of the highest maintenance devices in the system. Electrochemical compression requires no moving parts within the cell, resulting in less maintenance due to wear, and also is highly efficient, with very low voltage penalty. The primary efficiency loss in electrochemical compression of hydrogen at high pressure is due to back diffusion of the compressed gas to the other cell chamber. Still, the overall efficiency still competes very well with mechanical compression to thousands of psi, as will be shown in this talk.
Proton exchange membrane (PEM)-based electrolysis enables combining the generation of hydrogen through water-splitting with the direct electrochemical compression of the gas. These membrane-based systems also have the advantage that they are capable of differential pressure operation. While there are applications for both pressurized oxygen and hydrogen, the differential pressure capability is especially attractive for generating high pressure hydrogen while maintaining the water-oxygen loop at ambient pressure, due to the inherent safety risks of high pressure oxygen.
Proton OnSite, the market leader in PEM electrolysis, has been increasing the proven output pressure of PEM electrolyzer devices, with demonstration of 350-bar (5,000 psi) hydrogen generation and 250-bar (3600 psi) oxygen generation, both in full differential pressure mode (see Figure). The hydrogen cell stack has been scaled to a capacity of 4.5 kg/day and is certified to meet the relevant codes and standards. This talk will address the challenges and successes for both hydrogen and oxygen compression at Proton, and potential best fits for these technologies.

Figure 1
Relating Temperature-Dependent Aging Rate to Cathode Materials in Commercial 18650 Li-Ion Battery
Authors: Wang Han , Whitacre Jay 
Published: February 2020

Temperature plays an important role in battery aging rate. Previous reports1-3of commercial batteries with different cathode materials revealed the relationship between aging rate and cycling temperature ( between 25oC and 70oC ) can be described by Arrhenius plot. In other words, battery aging rate increases with increasing cycling temperature within range from 25oC to 70oC. While most Li-ion batteries suffer significant capacity loss when cycled at elevated temperatures, previous report4 has suggested that high temperature abuse testing had nearly no effect on aging rate of commercial 18650 NCA-based batteries, an effect not reported for batteries with LiCoO2or other common chemistries. We have investigated this effect further and reported that long-term constant current cycle testing of commercial 18650 NCA–based batteries at elevated temperature showed less capacity loss than control testing performed at room temperature, as shown in figure 1. Furthermore, the batteries cycled at room temperature exhibited excessive SEI formation on anode surface whereas there was much less SEI formation in the elevated temperature testing.
Mechanisms such as excessive lithium plating have been put forward as a possible cause4, though this would not explain why NCA-based batteries outperform batteries based on other similar cathode chemistries. We will present several possible hypotheses that describe this aging mechanism with a focus on understanding the relationship between SEI formation on the anode and cathode surface chemistry.
Reference:
1. Ramadass, P.; Haran, B.; White, R.; Popov, B. N., Capacity fade of Sony 18650 cells cycled at elevated temperatures Part I. Cycling performance. J Power Sources
2002,
112(2), 606-613.
2. Situ, W. F.; Yang, X. Q.; Li, X. X.; Zhang, G. Q.; Rao, M. M.; Wei, C.; Huang, Z., Effect of high temperature environment on the performance of LiNi0.5Co0.2Mn0.3O2 battery. Int J Heat Mass Tran
2017,
104, 743-748.
3. Waldmann, T.; Wilka, M.; Kasper, M.; Fleischhammer, M.; Wohlfahrt-Mehrens, M., Temperature dependent ageing mechanisms in Lithium-ion batteries - A Post-Mortem study. J Power Sources
2014,
262, 129-135.
4. Waldmann, T.; Kasper, M.; Wohlfahrt-Mehrens, M., Optimization of Charging Strategy by Prevention of Lithium Deposition on Anodes in high-energy Lithium-ion Batteries – Electrochemical Experiments. Electrochim Acta
2015,
178, 525-532.

Figure 1
Oxygen Redox in Li-Ion Battery Chemistries
Authors: Roberts Matthew , Bruce Peter G. , Luo Kun , Guerrini Niccolo 
Published: February 2020

The energy density of lithium batteries is currently restricted by the cathode material, delivering ~ 160-190 mAh g-1.1 New high-energy-density cathode materials are much sought after to meet the increasing requirements of consumer electronics, electric vehicles and grid energy storage. The so called lithium-rich layered oxide materials (e.g. Li1-x[Li0.2Mn0.6Ni0.2]O2), exceed the conventional limit of charge storage as far more lithium (x ≈ 1, corresponding to 310 mAh g-1) can be extracted than can be accounted for through transition metal oxidation (x ≈ 0.4). The source of this “extra” capacity has been explained previously by a number of models including oxygen loss, electrolyte decomposition and anion redox.
Recently, several groups have identified that this “extra” capacity is resulting from a reversible oxygen redox process2-7. In this work, we examine in detail the charging process in Li[Li0.2Ni0.2Mn0.6]O2 with direct experimental evidence of a dominant O redox process, accompanied by a minor contribution from oxygen loss, when the material is charged beyond 4.4 V. The formation of hole states around the oxygen during charging was probed using soft x-ray absorption spectroscopy (SAXS), as shown in Figure 1. Additionally, recent results that underpin the oxygen redox process in a number of closely related Li-rich compositions will be discussed, as well as the requirements necessary to form holes on the oxygen in these compounds. The conclusions of this work, and that of other researchers working to understand anion redox, provide us with a guidance which can be used to discover future high energy density cathode materials.
References
1. Goodenough, J. B.; Kim, Y. Chem Mater
2010, 22, (3), 587-603.
2. Luo, K.; Roberts, M. R.; Hao, R.; Guerrini, N.; Pickup, D. M.; Liu, Y. S.; Edstrom, K.; Guo, J. H.; Chadwick, A. V.; Duda, L. C.; Bruce, P. G. Nat Chem
2016, 8, (7), 684-691.
3. Luo, K.; Roberts, M. R.; Guerrini, N.; Tapia-Ruiz, N.; Hao, R.; Massel, F.; Pickup, D. M.; Ramos, S.; Liu, Y. S.; Guo, J.; Chadwick, A. V.; Duda, L. C.; Bruce, P. G. J Am Chem Soc
2016, 138, (35), 11211-8.
4. Koga, H.; Croguennec, L.; Menetrier, M.; Mannessiez, P.; Weill, F.; Delmas, C. J Power Sources
2013, 236, 250-258.
5. Koga, H.; Croguennec, L.; Menetrier, M.; Mannessiez, P.; Weill, F.; Delmas, C.; Belin, S. J Phys Chem C
2014, 118, (11), 5700-5709.
6. Sathiya, M.; Rousse, G.; Ramesha, K.; Laisa, C. P.; Vezin, H.; Sougrati, M. T.; Doublet, M. L.; Foix, D.; Gonbeau, D.; Walker, W.; Prakash, A. S.; Ben Hassine, M.; Dupont, L.; Tarascon, J. M. Nat Mater
2013, 12, (9), 827-835.
7. Seo, D. H.; Lee, J.; Urban, A.; Malik, R.; Kang, S.; Ceder, G. Nat Chem
2016, 8, (7), 692-7.

Figure 1
Development of Novel Electrolyte Additives for Designed Surface Modification
Authors: Lucht Brett L 
Published: February 2020

An investigation of the effect of electrolyte on performance of in lithium ion batteries will be presented
The electrochemical performance of common electrolyte formulations will be discussed along with
detailed ex-situ surface analysis of the cycled electrodes. The ex-situ analysis allows the development of
an understanding of the role of the electrolyte and common additives in the structure of interfacial
electrode films on both the anode (solid electrolyte interphase, SEI) and on the cathode. Correlation of
the structure of the surface films with the performance limiting reactions in lithium ion batteries affords
insight into the mechanism of interfacial film formation and function. The mechanistic insight is used to
systematically develop novel additives designed for specific electrode surface modification to afford
optimized electrochemical performance. The electrochemical performance and ex-situ surface analysis of
electrodes cycled with novel Additives for Designed Surface Modification (ADSM) will be presented.
Sodium Titanate Nanowires As High Rate Anode Materials for Lithium-Ion Batteries
Authors: Liao Jinyun , Smith Taylor , Xing Yangchuan 
Published: February 2020

Sodium titanate has been studied as an attractive anode candidate for Na-ion batteries due to its low cost, environmental friendliness, ease of synthesis, and structural stability during cycling. However, Na ions are about 25% larger than lithium, which leads to slower charge/discharge rates. In addition, the larger diameter of Na ions compared with lithium causes the volume changes that occur from intercalation to be even more severe. Few reports thus far have focused on sodium titanate as an anode material in Li-ion batteries (LIBs), where Li+ can also be inserted into sodium titanate at low voltage.
The main disadvantage for sodium titanate as an anode material for LIBs is its low electronic conductivity, resulting in poor rate capability. Several approaches have been taken in an attempt to improve the electronic conductivity of sodium/lithium titanate, such as electronic material coating/mixing, ionic doping, comminution, etc.; but as of yet there has been no uniform carbon coating reported on sodium titanate for LIBs. In this work, we detail a facile technique to create uniform thin carbon coating layers on Na2Ti6O13 nanowires (NTO-C). In addition, we also explored self-doped Ti3+ on carbon coated Na2Ti6O13 nanowires (NTO-Ch) in an effort to further improve its electronic conductivity. The detailed results of the synthesis, characterization, and electrochemical performance of the NTO-based materials (NTO, NTO-C and NTO-Ch) will be presented.

Fig. 1 (a, b) TEM and HRTEM images of NTO-Ch nanowire. (c) Rate capability comparison of NTO-based nanowire electrodes in Li-ion batteries.

Figure 1
Develop a Facil Syntheis Process for Si-Alloy Anode Material for Li-Ion Batteries
Authors: Yang Johnny , Li Bin 
Published: February 2020

Silicon is regarded as one of the most promising anode materials because of its theoretical specific capacity (4200mAh/g) compared to commercially available graphite anodes (370mAh/g). However, Si electrodes suffer considerable volume expansion of up to 300% during electrochemical lithiation, leading to electrode cracking and pulverization of the Si, causing rapid capacity degradation. Various approaches had been used for using nanostructured Si materials have been applied to solve this problem, since the interval distance between nano structures and internal spaces in them can act as structural buffer space to accommodate the volume expansion of Si. Although some of the nanostructured Si materials achived considerably high capacity and cyclability, they are usually prepared by complicate and high cost synthetic process which are difficult to extend to large scale. The other approach is using active/inactive alloys as an efficient way to reduce volume expansion and improve cycling performance. The volume expansion of Si can be suppressed by the presence of inactive components, resulting in the maximum energy density at a given volume expansion. Literature has also shown commercially available and low-cost Si alloys can serve as high capacity Li-storage anodic host materials with certain cyclability. If such Si alloy compounds can be made with required chemical stoichiometry and structural architecture though a simple mechanochemical process.
Wildcat Discovery Technologies is developing facile synthesis pathway to prepare Si-alloy active/inactive material. Our approach utilized high-throughput combinatorial research to optimize synthesis process, Si-alloy composition and electrode component to improve the cycling performance of the anode material. Here we demonstrate that with optimized synthesis process, varied active Si and inactive alloy composition reveal a strong correlation between capacity and cyclability.
Highly Efficient Gel Polymer Electrolyte Operating at Room Temperature for All Solid State Battery Applications
Authors: Piana Giulia , Armel Vanessa , Franger Sylvain , Duffault Jean-Marc , Porthault Hélène 
Published: February 2020

Numerous incidents occurred in the past decades involving lithium batteries, from the explosion of car battery pack to the smartphones burning, highlighting the security issues of this kind of battery. The main danger comes from the liquid electrolyte which is thermally unstable and represents a weak barrier against lithium dendrite growth upon cycling. Polymer electrolytes are an interesting alternative to current liquid ones. Solid polymer electrolytes (SPE) are solvent free electrolyte and are composed of a salt and a polymer which gives mechanical properties. These SPE present an important safety increase but the electrochemical performance, especially at room temperature, remains very low. Another material family is under development: the Gel Polymer electrolyte (GPE). GPE are composed of a lithium salt, a polymer and a solvent which improves the electrochemical performance1,2.
In this work, we want to develop an original ‘’wet’’ chemical process to realize the electrolyte thin film. The chosen gel polymer electrolyte (GPE) is composed of an acrylate polymer matrix which gives the mechanical behavior and a liquid phase which gives the electrochemical properties. The liquid phase is a mixture of an ionic liquid and a lithium salt. The electrolyte is polymerized by UV-curing (Fig.1). In a first step, the GPE was characterized with an original in-situ impedance spectroscopy to monitor the polymerization reaction (Fig.2). Conductivity measurements reveal very high ionic conductivity (> 1 mS/cm), whatever the electrolyte composition, which was expected considering the high ionic content in the liquid phase. However, the lithium transference number is very low (< 0.1) leading to low lithium conductivity (~10-12S/cm). Raman spectroscopy was used to determine Li-TFSI coordination (Fig.3) which, could partially explain the low transference number. Electrolyte composition was improved to increase the transference number (up to 0.29). The as-obtained electrolyte was integrated in an all solid state battery with LiCoO2 cathode. Galvanostatic cycles of batteries integrating a GPE or a standard liquid electrolyte are presented in Fig.4. Cycling was done at ambient temperature with a high 1C C-rate and electrochemical results are very similar despite a slightly higher polarization with the GPE.
[1] M. Armand, Solid State lonics 69 (1994) 309-319.
[2] A. Arya, Ionics (2017).

Figure 1
Electrodeposition of Metal Oxide Nanoparticles for Li-Ion Battery Anodes
Authors: Ates Mehmet Nurullah , Busbee John 
Published: February 2020

Electrodeposition technique is one of the unique ways to synthesize cathode and anode active materials for Li-ion batteries. At Xerion Advanced Battery, we couple this technique with a technology where we deposit active materials directly to the current collector. Thus, we eliminate the use of the binder, conductive carbon in addition to their complex preparation. In this work, we report a facile non-aqueous electrodeposition method to obtain anode active materials for Li-ion batteries. This single step synthesis method offers several benefits for the active material. Of particular significance are i-) it can be directly deposited on 3D substrate ii-) nano-sized active materials can be achieved due to low-temperature synthesis and iii-) high purity.
Although Li insertion into the metal oxide anodes has relatively higher voltages than that of commercial anodes (graphite), they still offer great benefits such as low output voltages of Li-ion cell which is necessary for devices requiring low voltages. This application is particularly received great attention from electronic (optics and chips) industry. We will specifically discuss the Co and Mn-based metal oxides and their electrochemical performances in conjunction with their structural and morphological data. Anode active materials on different 3D structures, including Ni scaffold and corrosion resistance fibers, will be evaluated and discussed. Figure 1 shows the FESEM image of a direct conformal deposition of Co3O4 nanoflakes on corrosion resistance fibers. Our preliminary data revealed that this anode material can deliver up to 2000mAh/g capacities at relatively low rates. Rate capabilities will be evaluated using different 3D substrates.

Figure 1