bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Electrolyte Amount on Electrochemical Properties of Coin-Type Lithium-Ion Cells
Authors: Han Taeyeong , Lee Hoogil , Kim Seokwoo , Ryou Myung-Hyun , Lee Yong Min 
Published: February 2020

Most of electrochemical data in published papers are obtained from coin-type cells, which consist of small disc-type cathode/anode pairs, a little larger separator, and excess liquid electrolyte. In particular, comparing to commercial LIB cells, it should be clearly understood that too much electrolyte can give a positive or negative effect on electrochemical properties. However, there have been few reports on this issue, and they are not fully investigated.
Thus, we try to figure out this point with coin-type cells. The amounts of liquid electrolyte are controlled by measuring the coin cell mass difference before and after assembly. Three different coin cells are evaluated to compare the initial discharge capacity and coulombic efficiency, electrochemical impedance, c-rate capability, and cycle life at room temperature. And then, the operating or storing temperatures are also changed. Finally, some electrolyte additives are also investigated under the different liquid electrolyte amounts in coin cells.
Acknowledgements
This work was supported by the Energy Technology Program of the Korea Institute of Energy Technology Evaluation and Planning(KETEP) granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20142010102980)
Ionic Structure and Physical Properties of Fluorinated Alkyl-Phosphate Solutions Dissolving Lithium Salts
Authors: Todorov Yanko , Fujii Kenta , Aoki Masahiro , Mimura Hideyuki , Yoshimoto Nobuko , Morita Masayuki 
Published: February 2020

Fluorinated alkylphosphates (FAPs) have been examined as nonflammable organic solvents for lithium-ion battery (LIB) electrolytes. Some research groups have already reported on the contribution of FAPs as either co-solvents or additives to the improvements in the safety of the battery system. There have also been publications concerning FAPs that can improve the battery performance under high-voltage operation by their use as the co-solvents in the electrolyte system. The characteristics of the electrolyte system are strongly dependent on the physico-chemical properties of the electrolyte solution. In the present paper, we have examined several combinations of FAP as the solvent and lithium salts as the electrolyte solute, and investigated the relationship among the solution composition, ionic structure and such physico-chemical properties as viscosity and ionic conductivity.
As a typical FAP, tris-2,2,2-trifluoroethyl-phosphate (TFEP) has high solubility toward conventional lithium salts, LiPF6, LiBF4, and Li(CF3SO2)2N (LiTFSA). The order of the ionic conductivity of the TFEP solution was LiTFSA>=LiPF6>LiBF4 over a wide temperature range. Concentration dependence of Walden’s product (the product of ionic conductivity and viscosity) of the electrolyte solution suggested that the degree of ionic association or ion-pair formation depends on the anionic species in the lithium salt. The IR/Raman spectra of the electrolyte solutions also showed that the ionic structure including the solvent coordination (solvation) of Li+ is different among the electrolyte composition. The solvation number of Li+ in TFEP was determined by the IR/Raman spectra, and was found to change from 2 to 4, depending on the anion. The DFT (Density Functional Theory) calculation gave the stabilized configuration of the solvated Li+ in TFEP that also depends on the anionic species.
An FAP with smaller number of F-atom, bis(2,2,2-trifluoroethy)ethyl phosphate (BTFE), and triethylphosphate (TEP: no F-atom) for comparison were also examined as the solvent of the electrolyte solution. The number of F-atom in the solvent much influenced the solubility of the lithium salt, and hence the conductivity behavior of the resulting electrolyte solution. In conclusion, the molecular structure of FAP influences the ionic structure of the electrolyte solution, which contributes to the electrochemical stability of the electrolyte system in LIB.
Gamma'-V2O5 : A New Sodium-Insertion Material Operating at 3.3 V Vs. Na+/Na
Authors: Baddour-Hadjean Rita , Safrany-Renard Marianne , Pereira-Ramos Jean-Pierre , Muller-Bouvet Diane 
Published: February 2020

A new sodium insertion compound, γ'-V2O5, was prepared by the chemical oxidation of γ-LiV2O5 phase using NO2BF4 as oxidizing agent. One sodium ion per mole of γ'-V2O5 can be inserted in γ'-V2O5 involving a high V5 +/V4 + redox potential of 3.5 V vs. Na+/Na. A fully reversible capacity of 145 mAh g− 1 was obtained at C/60, at 50°C (figure 1). The γ'-V2O5 electrode can deliver a high discharge capacity of 125 mAh g− 1 at C/20 rate at 50°C, stable over 50 cycles. An excellent retention capacity is also demonstrated over 90 cycles at RT: capacities in the range 60-80 mAh. g-1 in the C/5-C/20 range against 100-125 mAh g-1 at 50°C were recovered. A discharge capacity of 80 mAh g− 1 was still available after 90 cycles at C/20 rate. A two phases mechanism involving the γ'-V2O5 / γ-NaV2O5 system was evidenced from X-ray diffraction and Raman spectroscopy measurements. The structural features of the fully sodiated γ-NaV2O5 phase, with an unusual expansion along the c axis (+2 Å/ γ'-V2O5) were solved (inset in figure 1). These results revealed that the γ'-V2O5 forms a new competitive cathode for the reversible intercalation of sodium ions.

Figure 1
Na-Ion Batteries Based on Na-Rich Layered Oxyde and Optimised Hard Carbon: An Study of the Electrode/Electrolyte Interphase
Authors: Santos Pena Jesus , Montigny Benedicte , Autret Cecile 
Published: February 2020

Sodium ion batteries (NIB) represent nowadays one of the most promising « beyond Li » technologies. However, and according to recent reviews [1], the development of a true market based on NIB strongly depends on optimizing positive/negative electrode couples delivering high potentials and with a suitable electrolyte.
Research carried out in the PCM2E/GREMAN laboratories is focused on the synthesis and electrochemical characterization of positive electrodes based on new materials ascribed to the Na-rich oxide family, not containing expensive and toxic ions as cobalt. In a first time, sodium half-cells with very nice capacities, close to 140 mAh/g, have been successfully prepared in our laboratories. In order to ensure capacity retention, we have also studied different electrolytes by measuring their impact on the electrode/electrolyte interphase. Spectroscopic techniques as XPS and EIS are helpful for this goal. More recently, our laboratories are focusing on the building of full cells containing such oxides against optimized hard carbon-based composites as negative electrode, with increased conductivity.
In this presentation we will show the first results on these full NIBs and analyze their cycling properties by the use of different physico-chemical and electrochemical techniques.
[1]
Intercalation State of PF6
- in Graphitic Carbon for High Potential Dual Carbon Battery
Authors: Fukuda Taro , Ishihara Tatsumi , Inda Keisuke , Ida Shintaro , Akbay Taner 
Published: February 2020

Recently, strong demand has arisen for batteries with large capacities to support various types of mobile equipment. Li-ion batteries (LIBs) have been widely used for this purpose. In Li ion battery, intercalation of Li is only used but anion in electrolyte is not used for storage of electric energy. However, there is high interest on PF6
- intercalation into graphitic carbon and by using intercalation of Li+ and PF6
- into graphitic carbon for anode and cathode, respectively, electric energy can be storage. This battery is called dual carbon battery, however, electronic state of PF6
- into graphitic carbon is not thoroughly understood up to now. In this study, electrochemical intercalation reaction of PF6
- into graphotic carbon was studied by using solid state NMR and also XPS. Quantum calculation is also applied for estimating the stable structure of PF6
- sandwiched between graphitic sheets.
During electrochemical intercalation of PF6
-, reduction of PF6
- will be occurred and so XPS measurement was performed to estimate the change of oxidation state. In spite of several oxidation number, there is no change in valence state of P5+, however, XPS spectra of F- shifter to high binding energy suggesting that reduction of F- occurred during intercalation. NMR measurement of F and P also suggested that chemical shift was mainly observed on F peak but no change in P peak. In addition, coupling constant of F is significantly changed suggesting that the structure of PF6 may be changed during intercalation of PF6. From quantum calculation of stable structure of PF6 in graphene sheet, tilting structure is the most stable structure which is well agreed with the results of NMR measurement. Diffusivity of PF6 in graphitic carbon is also estimated and the observed diffusion constant is almost the same with that of Li in carbon and this is well explained the superior rate property of dual carbon battery.
In-Operando X-Ray Diffraction of Na-Ion Batteries
Authors: Hall Nikita , Lain Michael J , Kendrick Emma , Gruar Robert , Beattie Shane D 
Published: February 2020

Future demand for lithium-ion batteries is predicted to increase continuously due to their use in portable electronic devices and larger-scale energy storage, such as hybrid electric vehicles and static energy storage systems. Sodium is ubiquitous and significantly cheaper than lithium. Recent advances in sodium-ion battery technology has achieved promising results, with energy, power and cycle life comparable to Li-ion technology.1

Among cathode candidates, layered oxides offer many advantages due to their simple structures, high capacities, and ease of synthesis. However, there are major challenges to overcome, such as: low operating voltage, long term stability of host structure, high polarisation and the stability of the sodium in the P2-phase.2 In general, ternary and quaternary transitional metal (TM­) systems offer the most advantages, due to the ability to tune the material with different TM at different percentages. SHARP Corp. have been developing a variety of layered oxides for sodium-ion battery applications. One of the most promising candidates to date is the quaternary TM system, NaNixSnyMnzTiyO2 giving an experimental capacity of 175 mAh/g and an average voltage of 3.2 V. However, the cycle stability of this material requires improvement. In order to understand this loss in capacity over cycle life, in-operando x-ray diffraction was carried out in coin cell configuration vs hard carbon, containing either one or two beryllium windows depending on the x-ray source used. Initially, this project looked at the material in-situusing low energy laboratory x-ray diffraction, but the energy of the x-ray source is not sufficient to identify the different phase transitions throughout sodiation/desodiation. By means of using a synchrotron x-ray source and following real-time electrochemical performance, this experiment has allowed the identification of key phase transitions throughout initial sodiation at a rate of C/20 then continued cycling at a rate of C/10. What is particularly interesting is the corresponding phase transition that occurs at high voltage, with a defined plateau from 3.9 to 4.3 V. The corresponding redox reaction is unstable thus small loses of capacity is observed through cycling. By identifying this phase, and understanding what the structural changes to the cathode material are, there is the possibility to tune this material and therefore stabilising this high voltage phase-transition.
Sion Power's Licerion®
High Energy Batteries
Authors: Mikhaylik Yuriy 
Published: February 2020

Sion Power Corporation has created
Licerion®

, a comprehensive battery system that significantly enhances energy and cycle life of rechargeable batteries with metallic lithium anode. The core element of Sion Power’s
Licerion®
technology is a physically protected metallic lithium anode. Physical protection is based on ceramic-polymer composite membranes and is combined with specialized electrolyte systems providing chemical protection of exposed metallic lithium surface. This approach addresses safety and cycle life problems that have historically plagued lithium metal electrodes. Protected lithium anodes are currently combined with intercalated metal oxide cathodes typically used for Li-ion batteries (
Licerion®
- Ion) and with advanced sulfur cathodes (
Licerion®
- Sulfur). Sion Power Corporation in collaboration with BASF is working aggressively on realizing the impressive potential of the
Licerion®
technology targeting 500 Wh/kg, 1000 Wh/L and 1000 cycles. This presentation will discuss:

Failure mechanisms of rechargeable batteries with metallic lithium anode.

Current status of 350 - 400 Wh/kg Sion Power cells with metal oxide and sulfur cathodes and their high power and extreme low temperature variations.

Approaches pursued by Sion Power in collaboration with BASF towards next generation of
Licerion®
- Sulfur and
Licerion®
- Ion batteries targeting to meet and exceed requirements for EV application and for extended unmanned aerial vehicle (UAV) flights.
Understanding High Capacity in Li-Rich 3d Cathode Materials
Authors: Roberts Matthew , Luo Kun , Bruce Peter G. , Hao Rong 
Published: February 2020

Lithium rich layered cathodes, which offer increased capacity, have, for several years, been regarded as one of the next major advances, able to store charge by invoking transition metal and oxygen redox processes in the same material. However, they are still challenged by problems such irreversible first cycle capacity, voltage fade on cycling related to changes in the structure. Recently important work has been carried out to better understand the origin of the high capacity and the voltage fade.
In this contribution we shall present data probing the nature of the O redox states in Li rich 3d transition metal oxides, on the nature of O loss probed by isotopic substitution and on the degree of oxygen loss vs oxygen redox. We shall also report on a new sol-gel synthesis for Li1.2Mn0.54Ni0.13Co0.13O2. The electrochemical performance is shown in Figure 1. The cycling stability of the material is good with a capacity of ~250 mAh g-1 maintained after 100 cycles.
Figure 1. Load curve and cycleability data of sol-gel prepared Li1.2Mn0.54Ni0.13Co0.13O2 at a rate of 50 mA h g-1.

Figure 1
Single Particle Approach for Structure Characterization of Solid-State Synthesized Li4Ti5O12
Authors: Pelegov Dmitry V. , Slautin Boris N. , Kuznetsov Dmitrii K. , Zelenovskiy Pavel S. , Alikin Denis O. , Kiselyov Eugene A. , Kholkin Andrei L. , Shur Vladimir Ya. , Gorshkov Vadim S. 
Published: February 2020

Synthesis of any material means that the obtained product contains some volume of other phases. These impurities sometime are neutral, sometimes worsen the functional properties of the target material, and sometime can cause unwanted side reactions. In production of electrode materials for markets of electric vehicles and renewable/grid energy storages, such material heterogeneity is turned up due to drastically increasing demands in not expensive large-scale production and required decreasing of grains sizes. Wherein, despite the modern level of nanotechnology, the structural characterization is still mainly made by avaraging methods. For the first time we demonstrate that structural heterogeneity in commercial negative electrode material Li4Ti5O12 with sub-micron grain size synthesized using standard solid-state method can be described locally in terms of structural characterization of single particles. Combination of micro-Raman Spectroscopy and Scanning Electron Microscopy has allowed to consider phase transitions during solid-state synthesis from principally new angle. Proposed local approach can be used as an addition to integral techniques not only for Li4Ti5O12, but also to a wide range of commercial products.
Solid state synthesis of Li4Ti5O12 was made using chemically pure titanium dioxide TiO2 and chemically pure lithium carbonate Li2CO3by the following reaction:
2Li2CO3 + 5TiO2 = Li4Ti5O12 + 2CO2↑ (1)
Our modification of usual solid-state method, based both on analysis of intermediate reactions and review of the published data, uses three consequent synthesis stages with intermediate grinding which increased influence surface layers on material physical properties. In order to simplify other phases observation we knowingly increased the content of phase diagram nearest compositions TiO2 и Li2TO3by using partial (incomplete) synthesis with skipped third stage.
Raman spectra of single particle (Figure 1) clearly demonstrate heterogeneity of phase transformations during reaction (1) and allow making us some conclusions about the processes peculiarities which can’t be made otherwise.
Figure 1: SEM images and corresponding Raman spectra of single particles of final phase Li4Ti5O12 and two nearest phases Li2TiO3 and TiO2 rutile. SEM images sizes are 0.8×1.0 µm.

Figure 1
Thermodynamic Assessment of the Hydrogen Sorption Reaction in the System Li-Si-H
Authors: Biedermann Franziska 
Published: February 2020

Recently, extensive studies using silicon anodes in lithium ion batteries (LiB) have shown that the Li-Si-system is an attractive alternative to the currently dominating graphite anode in view of costs and specific capacity. Currently the main obstacle of silicon is the poor charge/discharge cycling stability and capacity fading due to the large volume variation during charging/discharging. However, remarkable progress has recently been achieved by using thin films of silicon or silicon nanowires to relieve the mechanical stress [1]. It is indisputable that future progress in lithium silicide applications will require fundamental knowledge of the physicochemical properties of the various lithium silicide phases. Especially accurate thermodynamic quantities are crucial for the understanding as well as modelling of phase, reaction and electrochemical equilibria.
In contrast to the numerous phase diagram studies reported in the literature, only few reliable thermodynamic quantities were available. Motivated by this situation, we recently reported experimental heat capacities and entropies of the lithium silicides Li17Si4, Li16.42Si4, Li13Si4, Li7Si3 and Li12Si7
[2,3]. Presently, the standard molar enthalpies of formation of the lithium silicides seem to be one of the most unreliable fundamental data because available values scatter by about 10 % which is unacceptable in view of reliable thermodynamic equilibrium calculations.
This contribution is focused on the accurate experimental determination of the standard enthalpies of formation DFH°(298) of the lithium silicides Li17Si4, Li13Si4, Li7Si3 and Li12Si7. For this purpose the hydrogenation/dehydrogenation equilibria in the system Li-Si-H were investigated at three different temperatures (450 K, 475 K, 500 K) using a Sievert’s type apparatus. The measurements based on two different sample types: (i) pure silicide and (ii) a stoichiometric mixture of lithium hydride and silicon. The calculation of the standard enthalpies of formation by using the slopes of the classical van’t Hoff plots results in uncertainties of at least 10 %. Due to this unsatisfying large error, an alternative evaluation method is demonstrated linking the hydrogen equilibrium pressures peq(H2) from the sorption measurements with our precise heat capacity and entropy data of the lithium silicides. The obtained values for the standard enthalpies of formation show strongly reduced uncertainties of less than 2%. Finally, it will be shown that the phase diagram of the Li-Si-system can now be calculated (CALPHAD) with excellent quality using a complete set of experimental thermodynamic data.
[1] M. T. McDowell, S. W. Lee, W. D. Nix, Y. Cui, Adv.
Mater.
2013, 25, 4966–4985.
[2] D. Thomas, M. Abdel-Hafiez, T. Gruber, R. Hüttl, J. Seidel, A. U. B. Wolter, B. Büchner, J. Kortus, F. Mertens, J. Chem. Thermodyn.
2013, 64, 205–225.
[3] D. Thomas, M. Zeilinger, D. Gruner, R. Hüttl, J. Seidel, A. U. Wolter, T. F. Fässler, F. Mertens, The Journal of Chemical Thermodynamics
2015, 178–190.
Development of a Modified Coin Cell for in-Situ, Long Duration Synchrotron X-Ray Powder Diffraction
Authors: Baker Annabelle , Day Sarah , Tang Chiu C. 
Published: February 2020

The use of in-situ X-Ray Powder diffraction for the study of new battery materials has grown in recent years, providing an insight into the effects that charge/discharges cycles have on cathode materials. These experiments are often limited to short periods of time and therefore only allow for one full charge/discharge cycle/multiple fast cycles to be observed. The result is that material characteristics may be well understood for the first cycle but little is known about the long term processes that ultimately lead to failure of the cell over longer timescales.
The Long Duration Experiment (LDE) Facility on Beamline I11 at Diamond Light Source is the first of its kind, housing experiments that require periodic, in-situ monitoring over periods of months to years. It is an ideal facility for the long term study of battery materials, allowing data to be collected over many cycles. To conduct these experiments a new cell had to be developed that would allow the transmission of X-rays, while also remaining impermeable to air and moisture for a long period of time. Previous in-situ diffraction experiments of battery materials have generally involved using unconventional cells. While these are effective, they are often not stable for long periods of time and are not true representations of real-life battery systems. By modifying a standard CR2032 coin cell case, we have been able to produce a cell that fits this purpose. Laser thinning was used to reduce the thickness of a small section of the cell to 50μm, allowing sufficient X-ray transmission without compromising the integrity of the cell.