bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Liquid and Solid State NMR Investigations of Electrolytes for Beyond Lithium Ion Applications
Authors: Greenbaum Steve , Gobet Mallory , Peng Jing , Munoz Stephen , Cresce Arthur v. , Russell Selena M. , Borodin Oleg , Xu Kang , Zimmerman Michael , Leising Randy 
Published: February 2020

Nuclear magnetic resonance (NMR) has been productively employed to investigate ion transport and solvation in standard carbonate-based Li ion battery electrolytes and in solid polymer electrolytes based on poly(ethylene oxide) (PEO). Future electrochemical power sources require new electrolytes to adapt to disruptive changes in the basic working chemistry, such as moving from Li ion to Na ion, or to Li metal electrodes. We highlight two recent collaborative activities on electrolytes in our group (i) Na ion; (ii) Li metal polymer.
Using a combination of 23Na, 19F and natural abundance 17O NMR, and pulsed field gradient diffusion in a collaboration with the U.S. Army Research Lab, we have examined NaPF6 solutions in binary solvent mixtures ethylene carbonate (EC) and ethylmethyl carbonate (EMC) for possible cation solvation preference as a function of EC/EMC ratio. Spectroscopic evidence demonstrate that the Li+ and Na+ cations share a number of similar ion–solvent and ion-ion interaction trends, such as a preference for a solvation shell rich in cyclic carbonates over linear carbonates and fluorinated carbonates. However some differences are noted, in particular a somewhat weaker ion-solvent interaction for Na+. Ionic Materials, Inc. has invented a novel polymer with extremely high ionic conductivity over a range of temperatures, even surpassing that of a commercial porous separator containing the standard liquid carbonate-based electrolyte at room temperature. This solid polymer can be reliably extruded into very thin films, is non-flammable, has attractive mechanical properties for lithium dendrite suppression, is electrochemically stable against Li, and is compatible with a variety of different anodes and cathodes. The polymer electrolyte is based on an inexpensive semicrystalline commercially available polymer such as polyether ether ketone or polyphenylene sulfide and Li salts familiar to the battery and polymer electrolyte communities. The ionic transport mechanism is unlike that which characterizes the PEO salt complexes – that is ion mobility is completely decoupled from polymer host motion, as verified by differential scanning calorimetry and NMR. In fact NMR pulsed gradient measurements reveal Li self-diffusion coefficients at room temperature that are an order of magnitude higher than in the ceramic ion conductors of the Li10GeP2S12 class and thus the highest in any known solid. Furthermore, the Li+ transference number determined electrochemically and by NMR is > 0.6.
All-Solid-State Lithium Batteries Based on Semi-Interpenetrating Network Solid Polymer Electrolyte and Composite Electrode
Authors: Kim Do Youb , Chang Ho Young , Suk Jungdon , KIM Dong Wook , Kang Yongku 
Published: February 2020

Poly(ethylene oxide) (PEO)-based solid polymer electrolytes (SPEs) have been considered as promising candidates for solid-state Li-ion battery (LIB) electrolyte that can replace current liquid electrolyte system.[1] However, PEO-based SPEs have critical problems for practical use in that the ionic conductivity is relatively low at an ambient temperature, and the high interfacial resistance between the SPE and electrode is relatively high. For better performance of solid-state batteries, SPEs should improve the ionic conductivity, strengthen the mechanical properties, and reduce the interfacial resistance between SPE and electrode as well.[2]
In this study, we report highly promising SPEs for all-solid-state LIBs based on a novel cross-linker having poly(ethylene oxide) (PEO) branches with very high ionic conductivity, improved mechanical stability, and good electrochemical stability. In order to reduce the interfacial resistance between SPE and electrode, we introduced a semi-interpenetrating network system through an in-situ polymerization of SPE precursor solution, and a composite electrode that contained an ionic conducting component. In addition, we also introduced Li-ion conducting powders into the SPE to increase ionic conductivity and mechanical strength of the SPE. As prepared SPEs had relatively high ionic conductivities of ca. 5~7 x 10-4 S/cm at an ambient temperature, good mechanical strengths, and electrochemically stable up to 5.2 V vs. Li/Li+. A cell composed of LiFePO4 composite cathode, Li metal anode, and SPE showed good specific capacity of 140 mAh/g at 0.5 C, cycle stability, and rate capability (95 mAh/g at 2 C). Specially, when the ionic conducting powder introduced into the SPE, Li+ transference number rose by 50 %, and thus the cell exhibited improved rate capability and mechanical strength. Finally, all-solid-state pouch-type cells were assembled with the SPEs exhibited stable electrochemical performance, even under a severely bent and folded state.
[1] A. Ghosh, C.S. Wang, P. Kofinasb, J. Electrochem. Soc.
2010, 157, A846.
[2] K. Xu, Chem. Rev.
2004, 104, 4303.
New Material Routes to Polymeric Solid Electrolytes
Authors: Janietz Silvia , Meyer Wolfdietrich , Asaftei Simona 
Published: February 2020

In our work photocurable liquid ionic compounds (PLICs) [1] and oxygen rich crosslinkers (ORCs) with carboxy- and ethoxygroups build the base of a monomer blend system [2] to obtain thin films on electrode surfaces of new polyionic polyacrylates as polymeric solid electrolytes (PESs) in a battery buildup [3].
The aim of our study is to show that the low ionic forces in an ionic liquid is preserved when the cation of the PLIC is fixed covalently bonded into a polymer network and turns into a PES after curing process. With similar intention ORC are designed to achieve a fixation of carboxy groups as an ideal chelator for lithium ions within a polymeric solid electrolyte.
The synthesis of PLICs and ORCs is described and characterized by NMR, IR and melting points. Formulation of PLICs, ORCs and lithium salts has been bladed and UV cured direct on Li foils as electrode material and the ionic conductivity in a half cell setup were determined by impedance spectroscopy. The free foils of PES show high temperature stability and the absents of crystallinity in DSC measurements.
Secondly a polymer design concept is presented that combine ion conductivity and mechanical stability in a block-co-polymer consisting of a PEG unit and a rigid rod aromatic unit aiming as a new material basis for battery separators.
Sulfur-Based SEI-Forming Additives for Lithium-Ion Batteries
Authors: Jankowski Piotr , Wieczorek Wladyslaw , Johansson Patrik 
Published: February 2020

Due to the increasingly growing demands for reliable and high capacity energy storage in mobile devices and electric vehicles, tremendous efforts are being made to improve life-length, performance, and safety of lithium-ion batteries (LIBs). For LIBs the solid electrolyte interphase (SEI), formed by electrolyte reduction on the anode surface, is a key element and one way to improve LIBs is to control the process of SEI formation, rather than relying on spontaneous formation by electrolyte decomposition. Application of special molecules, SEI-forming additives, is a viable approach.
We here present a systematic study of several different sulfonyl compounds, as SEI-forming additives for a standard LP30 battery electrolyte. Electrochemical analysis of the resulting electrolytes shows a notable difference in reduction ability. The compositions of the formed SEI-layers were examined and all experimental data confronted with DFT calculations to better understand the influence of the chemical structure of the additives on the reduction properties. Finally, the electrolytes were cycled in graphite/LFP full cells to study the long-term stabilization properties of the SEI-layers formed.
Ionic Liquid Based Electrolytes for Electrical Storage
Authors: von Czarnecki Peter , Ahrens Maria , Iliev Boyan , Schubert Thomas J. S. 
Published: February 2020

Ionic liquids (ILs) – salts that are liquid at temperatures below 100°C – have gained big popularity over the past years and have become products of industrial interest, instead of just being lab curiosities. Ionic Liquids show interesting combination of physical and chemical properties, such as tunable viscosity and conductivity, chemical and thermal stability as well as large electrochemical windows and incombustibility at temperatures below their decomposition point. Especially the last two allows their use as safe electrolytes in batteries, supercapacitors and other energy devices.[1-4]

Figure 1: Temperature-dependent viscosity of IL-mixtures.

One of the main disadvantages of ILs - their high viscosity - can be overcome by using mixtures (Figure 1). In this talk we will present our latest results and developments in the field of ionic liquid based electrolytes for batteries and supercapacitors. In the latter cycling stability over 8 000 000 cycles has been achieved. The use of mixtures of ionic liquids and suitable additives in order to enhance performance and safety of zinc - air, aluminum - air and silicon - air batteries will also be discussed.

Literature:

[1] M. A. Taige, D. Hilbert, T. J. S. Schubert, Z. Phys.
Chem. 226 (2012) 129-139.
[2] D. Aradilla, P. Gentile, V. Ruiz, P. Gómez-Romero, J. Wimberg, B. Iliev, T. Schubert, S. Sadki and G. Bidan, Adv. Nat. Sci.: Nanosci.
Nanotechnol., 2015, 6, 015004-015010.
[3] D. Gelman, B. Shvartsev, Y. Ein-Eli,
J. Mater. Chem. A

2(
2014)20237-20242.
[4] M. Kar, B. Winther-Jensen, M. Forsyth, D. R. MacFarlane, Phys.
Chem. Chem. Phys.

15 (2013) 7191-7197.

Figure 1
Evaluating Fluorinated Electrolyte Stabilities on Charged Ncm Cathode Surfaces with Potentiostatic Holds
Authors: Tornheim Adam , He Meinan , Peebles Cameron , Garcia Juan , Sahore Ritu , Dogan Fulya , Liao Chen , Iddir Hakim , Bareno Javier , Bloom Ira , Zhang Zhengcheng 
Published: February 2020

Organic carbonate electrolytes are commonly used in lithium ion batteries due to their wide electrochemical stability window and high lithium salt solubility. However, the high voltage of some cathode materials is above the stability of these conventional carbonate electrolytes (>4.5V vs. Li+/Li). One method of increasing the anodic stability of the organic carbonates is through substitution of the solvents with a fluorinated carbonates. In this work, we evaluate the stability of electrolyte formulations comprising combinations of either ethylene carbonate, fluoroethylene carbonate, or difluoroethylene carbonate as cyclic carbonates, and ethyl methyl carbonate or hexafluorodiethyl carbonate as linear carbonates. Stability of these electrolytes at both positive and negative electrodes was determined by lithium/graphite half cell tests, as well as 60 hour potentiostatic hold tests at 4.6 V vs. Li+/Li with NMC (LiNi0.5Mn0.3 Co0.2O2) cathodes and either graphite or LTO (Li4Ti5O12) anodes. In potentiostatic holds with NMC cathodes, the fluorinated electrolytes show enhanced stability (lower oxidation current) with the graphite anodes, while fluorethylene carbonate containing formulations show higher oxidation currents with the LTO anodes. These results indicate the feasibility of fluorinated electrolytes in enabling high voltage cathodes through stability of the cathode/electrolyte interface.

Acknowledgements

The work at Argonne National Laboratory was performed under the auspices of the U.S. Department of Energy (DOE), Office of Vehicle Technologies, under Contract No.
DE-AC02-06CH11357.
The submitted issue has been created by the University of Chicago as Operator of Argonne National Laboratory (“Argonne”) under Contract No. W-31-109-Eng-38 with the U.S. Department of Energy. The U.S. Government retains for itself, and others acting on its behalf, a paid-up, non-exclusive, irrevocable, worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the Government.
Suppressing the Dendrite Growth on Li Metal Anode Via Manipulating the Solid Electrolyte Interface (SEI) Formation
Authors: Liu Haodong , Zhou Hongyao , Xing Xing , Lee Byoung-Sun , Liu Ping 
Published: February 2020

The progressive advancements in communication and transportation has changed human daily life to a great extent. While important advancements in battery technology has come since its first demonstration, the high energy demands needed to electrify the automotive industry have not yet been met with the current technology. One possible anode is the Li metal, which has several distinct advantages over other anode materials. For example, it possesses extremely high theoretical specific capacity of 3860 mA h g-
1, and the lowest negative electrochemical potential.1 However, the uncontrollable Li dendrite growth on the Li metal during electrochemical cycling will cause serious safety problem, which brings up challenges in broadening the application of Li metal for Li batteries.
In this work, we successfully suppressed the Li dendrite growth on the Li anode by designing novel electrolyte systems. We observed an uniform solid electrolyte interface (SEI) layer was coated on the surface of Li metal anode through the scanning electron microscopy, this SEI layer helps to prevent the Li dendrite formation. Fig.1 compares the morphologies of deposited Li using different electrolytes. We also manipulated the composition of SEI by using different combinations of electrolyte solvents and Li salts. The chemical composition and structural information of the SEIs are investigated by X-ray Photoelectron Spectroscopy, X-ray diffraction, and Infrared Spectroscopy. Furthermore, this work demonstrates a new strategy of manipulating beneficial SEI formation, which shed light on the application of Li metal anode in high energy density batteries.

Reference

1. W. Xu, J. L. Wang, F. Ding, X. L. Chen, E. Nasybutin, Y. H. Zhang and J. G. Zhang, Energy & Environmental Science, 2014, 7, 513-537.

Figure 1
Detection and Influence of Residual Water Content on Electrochemical Performance of Solid State Polymer PEO-Litfsi Electrolytes
Authors: Graebe Heiko , Netz Andreas , Kwade Arno 
Published: February 2020

All solid state lithium-ion batteries are one of the promising candidates to power future electric and hybrid electric vehicles due to their outstanding potential for safety improvement and power density. Typically all solid state battery concepts require a lithium-metal (Li-metal) anode to achieve higher energy density. For reasons of processability, polymer based solid electrolytes are often a preferred material class to form the separator and cathode. However, maximum attention has to be paid on the interface of solid polymer electrolyte (SPE) and Li-metal due to the extreme reactivity. Side reactions at the interface cause an increase of the contact resistance and a rapid drop of the cell performance.
Generally solid polymer electrolytes consist of at least two components: a polymeric host and a lithium salt. A well-known combination is polyethylenoxide (PEO) and lithium bis(trifluoromethanesulfone)imide (LiTFSI), which can be prepared by dissolving the two components in a suitable organic solvent which is subsequently removed during a drying step. Although this process appears rather simple, the details of this procedure have a significant impact on the functionality and stability of the SPE. This impact comes from the residual water content, solvents and impurities which as a result react with the Li-metal and cause undesired aging effects.
We studied the drying time of PEO and LiTFSI in-depth based on different variations applying the Karl Fischer titration technique. Commonly for the SPE preparation, solvents like n-methyl-2-pyrrolidion (NMP), acetonitrile, methanol etc. are used which also contain certain amounts of water depending on the purity grade. The interface between Li-metal and SPE was characterized by impedance spectroscopy in symmetrical cells (Li|SPE|Li) at 80°C. The work in our laboratory demonstrates a non-damaging approach to produce water-free PEO and LiTFSI. The results show that the Karl Fischer titration technique is a useful method to determine the residual water content of the PEO and LiTFSI independent of different drying time periods and methods. Moreover, it could be demonstrated, that there is an impact of the residual water on the interface resistance between the Li-metal and the SPE.

Figure 1
Development and Mechanism Investigation of Novel Fluorinated Ethers As Secondary Solvent in Electrolyte for Lithium-Sulfur Batteries
Authors: Zhang Shuo , Lee Chang Wook , Lal Jyotsana , Hu Bin , Zhang Jingjing , Zhang Lu , Lau Ka-Cheong , Liao Chen , Zhang Zhengcheng 
Published: February 2020

Sulfur (S) has been identified as one of the most promising cathode material due to its high theoretical specific capacity (1675 mAh/g), good environment compatibility, and low cost. These features make lithium-sulfur battery a potential candidate for the next-generation battery, especially in electric vehicles and portable devices. However, the application of lithium-sulfur (Li-S) battery is still impeded by some limitations, including the low electrical and ionic conductivity of the elemental sulfur and the discharge product (Li2S), and the shuttle effect due to the presence the dissolved polysulfide (PS) species in electrolyte.
1,1,2,2-Tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TTE) has been identified as an effective secondary solvent in electrolyte for lithium sulfur batteries. In this study, fluorinated ethers (FEs) other than TTE were attempted in 1,3-dioxolane (DOL) based electrolyte, and comparison was made over cell performance, viscosity/conductivity of electrolyte, and aggregation states of lithium PS species.
1,1,2,2-Tetrafluoroethyl 2,2,2-trifluoroethyl Ether (HFE), ethyl 1,1,2,2-tetrafluoroethyl ether (ETE), and 1,1,2,3,3,3-hexafluoropropyl ethyl ether (HEE) were identified as promising alternatives to TTE to accommodate wider range of applications of Li-S batteries. However, amphiphilic FEs, like 1,1,1,2,2,3,3,4,4-Nonafluoro-6-(pentyloxy)hexane (NHPE) and 1,1,1,2,2,3,3,4,4,5,5,6,6-tridecafluoro-8-(pentyloxy)octane (TDPE) were not effective at all.
Depending on formula weight, viscosity and conductivity, cell performance of Li-S batteries containing electrolytes with different FEs also varied. And FEs with coulombic efficiency higher than that of TTE were discovered. In DOL/FE based electrolyte, the aggregation states of lithium PS species were investigated via small-angle X-ray scattering (SAXS), and revealed a variation in dimension of assemblies of lithium PS species in the presence of different FEs. The difference of cell performance can therefore be concluded as the variation in transport behavior of lithium PS species in electrolyte. In addition, this would offer some insights into the failure mechanisms of Li-S batteries, and promote further development of electrolyte for Li-S batteries.

Figure 1
Modeling Na2s Based Glassy Electrolytes for High Performance Solid State Sodium Ion Batteries
Authors: Dive Aniruddha , King Clarence C , Beckman Scott P , Martin Steve W , Banerjee Soumik 
Published: February 2020

Limited availability of lithium and safety concerns due to flammability of liquid electrolytes pose significant challenges to commercial lithium-ion batteries. To overcome these limitations, it is essential to explore technologies beyond conventional lithium ion batteries, particularly for electric power grid applications. Sodium ion batteries, particularly those employing solid electrolytes, are being explored as potential candidates. Solid state electrolytes are typically non – toxic and more environmental friendly, which provides them an edge over their liquid counterparts. However, obtaining relatively high ionic conductivity at room temperatures is challenging. In this work, we studied sodium sulfide (Na2S) based glasses as electrolytes for solid state sodium ion batteries. More specifically, sodium sulfide – silicon sulfide [0.5Na2S – 0.5SiS2] glass was explored. These glassy electrolytes were modeled using classical molecular dynamics (MD) approach. The interactions between various ions in the glass were defined using Buckingham type potential. All the glasses were formed using a typical melt – quench technique. Due to amorphous nature of the glass, a large number of initial glass structures were studied to obtain statistically reasonable model. The density of glass obtained through MD was observed to match quite well to the experimentally reported value. Further structural validation of the molecular model was performed by comparing the pair distribution function (PDF) for different pairs of ions for actual glass to those obtained from MD simulations. The ionic conductivity values for these glasses at room temperature have been observed to be in the range of ~ 10-5S/cm, which agreed well with the values obtained from the molecular simulations. Furthermore, the activation energy for ion hopping within the glass was obtained through MD and compared well with experimental data. A KMC site model was developed, based on inputs from MD, to evaluate the ionic conductivity of these glasses at a much larger length scale and the results agreed well with experimental measurements.
Interactions at the anode – electrolyte interface play a key role in determining the performance of sodium ion batteries. Ab initio MD simulations of pure sodium metal and glassy electrolyte interface were performed. Structural configuration of the sodium anode – glass interface was estimated by calculating the density distribution and PDF’s for various ion pairs. Additionally, Na+ ion transport near the interface was studied carefully to determine specific metallic sites that accommodate Na+ ions. The distribution of these favorable sites along with their respective site energies were calculated and provided as inputs to KMC site model that simulated actual battery charging – discharging cycles based on the above inputs from ab initio MD.