bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ionic Liquids at the Electrode Interface: Insights into Surface Passivation and Framework Expansion of Hard Carbon Anodes
Authors: Bridges Craig A. , Sun Xiao-Guang , Guo Bingkun , Heller William , He Lilin , Paranthaman Mariappan Parans , Dai Sheng 
Published: December 2020

Ionic liquids are being extensively explored as an alternative to carbonate-based electrolytes in reversible batteries, as they can exhibit lower flammability and volatility, and better overall safety. The polarity and acidity/basicity of ionic liquids can be tuned to control solubility, and can influence the electrochemical window and interfacial properties when used in batteries. In this study, 1-ethyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl) imide (EMIM.TFSI) and 1-methyl-1-propypyrrolidinium bis(trifluoromethanesulfonyl)imide (MPPY.TFSI) were selected because they are well-known, relatively stable ionic liquids with large electrochemical windows which show strikingly different behavior with carbonaceous anodes due to differences in interface passivation. High surface area mesoporous hard carbon anodes were employed to provide a large signal from the interfacial chemistry of these electrolytes during reversible cycling. A combination of operando small-angle neutron scattering (SANS) and ex-situ electrochemical studies were used to understand the differences in solid electrolyte interphase (SEI) for these ionic liquids, and the relationship of SEI formation to hard carbon microstructural changes. Reversible hard carbon expansion is observed in the first cycle for the electrolyte lithium bis(trifluoro-methanesulfonyl)imide (LiTFSI)/EMIM.TFSI related to EMIM+ intercalation and deintercalation before a stable SEI is formed, while a largely irreversible framework expansion of 15% is observed for the LiTFSI/MPPY.TFSI electrolyte. There is only relatively minor expansion and contraction in subsequent cycles after a suitable solid electrolyte interphase (SEI) has formed. Irreversible framework expansion in conjunction with SEI formation is found to be essential for the stable cycling of hard carbon electrodes.[1]
Acknowledgement: Research was sponsored by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division. Research at Spallation Neutron Source user facility was sponsored by the Division of Scientific User Facilities, Office of Basic Energy Sciences, US Department of Energy, under contract DE-AC05-00OR22725 with UT-Battelle, LLC.
[1] Bridges, C.A.; Sun, X.G.; Guo, B.K.; Heller, W.T.; He, L.L.; Paranthaman, M.P.; Dai, S. “Observing Framework Expansion of Ordered Mesoporous Hard Carbon Anodes with Ionic Liquid Electrolytes via in Situ Small-Angle Neutron Scattering.” ACS Energy Lett.
2017, 2, (7), 1698-1704.
Uranium Electrorefining in 3LiCl-2KCl Based Melts
Authors: Nikitin Dmitry , Zolotarev Daniil A. , Mukhametdyanov Artur D. , Volkovich Vladimir A. , Polovov Ilya B. 
Published: December 2020

Molten halides can be effectively employed for electrorefining of refractory and radioactive metals with relatively negative reduction potentials and high melting temperatures. In the present study electrorefining of uranium was studied for developing pyrochemical reprocessing technology of metallized spent nuclear fuels. 3LiCl-2KCl molten salt was chosen as the working electrolyte. Uranium containing electrolytes were prepared by dissolving UCl3 in the solvent salt melt in an argon filled glove box to obtain various desired concentrations of uranium in the electrolyte. The working temperature in the refining experiments varied between 450 and 750 °C.
The experiments on uranium electrorefining were carried out in a stainless steel semi-industrial water-cooled electrolyser. Crude uranium metal was loaded in a specially designed molybdenum anodic basket. Glassy-carbon crucible was used to hold the melt. Molybdenum rod was employed as a cathode.
The main goal of the electrolytic refining process is obtaining high-purity uranium metal. Specific energy consumption is also very important. The results of the electrolytic refining depend on various parameters. In the present study current density, temperature, uranium concentration in the electrolyte, and specific quantity of electricity passed through the cell were selected as variables, and the current efficiently was chosen as a response factor.
Dense and compact uranium deposits were obtained under low current densities, while application of relatively high current densities led to the formation of uranium dendrites. Intermediate values of current density allowed producing more coherent deposits that could be easily scraped off the cathode. Increasing temperature led to a sharp change of the cathodic deposits morphology. The reason for this is the formation of tetragonal beta-uranium instead of the low-temperature orthorhombic alpha modification.
The values of cathodic current efficiency in the most of experiments confirmed the three-electron scheme of uranium reduction. Cathodic current density under certain conditions exceeded 95 %. The amount of salt retained in the cathodic deposit varied from 7 to 25 %, values typical for dendrite electrolytic metals.
Aluminum Ion Species Transport in Pure and Additive Modulated Deep Eutectic Solvents (DES) Electrolytes
Authors: Paterno Domenec , Suarez Sophia 
Published: December 2020

The need for safe, low cost, high energy and density storage devices is ubiquitous the world over. Satisfying this need requires various energy storage and conversion applications, one of which is the aluminum ion batteries. One problem with expansion in their development and commercialization is the availability of optimized electrolytes. Recently, deep eutectic solvents (DES) have gained attention as electrolytes for energy storage devices. These solvents are similar to ionic liquids, but are generally cheaper and easier to prepare. Additionally, they are known to dissolve metal oxides which plague AIBs operation, and their solubility is dependent on the hydrogen bond donor. Because of their inherent tunability, we studied the effect of AlCl3 concentration (1:1 – 1.7:1 molar ratio), amide type (acetamide (AA), butyramide (BA), propionamide (PA)), viscosity reducing additive type and concentration, on the aluminum ion species and transport in AlCl3:amide DES electrolytes using multi-Nuclear (1H, 27Al) Magnetic Resonance (NMR) and AC Impedance Spectroscopy techniques, as a function of temperature. Below are a few noteworthy observations.

Figure 1. VFT plots of the ionic conductivity for AlCl3:AA (left) and AlCl3:PA (right) DES electrolytes.
Thirdly, the variable temperature 1H and 27Al spectra and T1 data for the pure and additives included DES electrolytes were very dependent on concentration, additive type and concentration, and species type. For example, in the 1:1 molar ratio electrolyte, the assigned AlCl2(amide)+ species had the longest T1, while the AlCl2(amide)2
+ had the shortest. Additionally, the inclusion of additives such as fluoroethylene carbonate (FEC) and propylene carbonate (PC) caused species specific increasing local ion dynamics, possibly through the reduction of bulk viscosity effects and Coulombic interactions. These results and more will be expounded upon in our presentation.
Firstly, for both AlCl3:PA and AlCl3:BA DES electrolytes, a maximum in ionic conductivity was observed at the 1.3:1 molar ratio. For AlCl3:AA DES the maximum occurred at the 1.5:1 molar ratio. Secondly, for the three amides conductivity values fell in the range of ~1 – 11 mS/cm over the temperature range of 288 – 363K. Additionally, the temperature dependence displayed curve-like behavior and were fitted using the VFT equation to reveal high levels of fragility and dynamic behaviors similarities to some pure ILs where the effective inter-conversion between the trans and cis conformations of the anion facilitated faster ion dynamics.

Figure 1
Preparation and Electrochemical Properties of Ambient Temperature Molten Chlorides Based on Quaternary Ammonium Chloride and MgCl2
Authors: Matsumoto Hajime , Akai Naoto , Oyabu Rie 
Published: December 2020

The research and development of magnesium secondary batteries using magnesium anode have been attracted much attention as one of the prospective post-lithium ion batteries due to the high theoretical capacity (3830 Ah/dm3) and without no resource constraints. However, it has been quite difficult to construct the magnesium batteries because practical electrolytes for the battery has not yet been developed.
We previously reported that TFSA-based ILs were not suitable for a Mg anode even in alkali metal binary molten salt such as MgTFSA2-KTFSA, which indicated that the existence of the TFSA anion disturbed a magnesium redox on Mg electrodes. [1] On the other hand, relatively smooth magnesium redox could be observed in 1-butyl-3-methylimidazolium chloride melts containing Mg[TFSA]2. [2] However, the electrochemical window of the imidazolium melt was limited by the reduction decomposition of the imidazolium.
In this study, we reported that ambient temperature molten chlorides could be obtained by mixing a quaternary ammonium chloride and MgCl2, which did not contain the TFSA anion and also imidazolium cations. The thermal properties and also physicochemical properties were investigated. The electrochemical response of a magnesium metal in the melt were also shown to indicate the possibility as an electrolyte for a magnesium anode battery.
[1] K. Kubota, H. Matsumoto, J. Electrochem. Soc., 167 (2020) 020541.
[2] H. Matsumoto, K. Kubota, ECS Transactions, 86(14) (2018) 21.
(Invited) Relating Ion Structures and Transport Properties of Ionic Liquids
Authors: Philippi Frederik David , Clark Ryan , Koutsoukos Spyridon , Hunt Patricia A , Welton Tom 
Published: December 2020

Whether used as electrolytes or solvents for synthesis both the bulk viscosity and the microscopic dynamics of ions in ionic liquids often determine the applicability of these. Hence, it is important to understand the connection between the structures of ionic liquid ions and these key properties. Features that contribute to these behaviours include ion mass, size, interactions, and flexibility and the ability of the ions to give rise to nanoscale segregation of charged and nonpolar domains.
In this work, we combine experimental and theoretical studies of a wide range of ionic liquids composed of structurally similar ions in an attempt to separate the relative contributions of these features to the transport properties of ionic liquids. We target a number of design parameters, such as the ions' central atoms (e.g., ammonium or phosphonium cations), ion substitution (e.g., alkyl chain length and degree of substitution of cations and fluorination of the anion).
In addition to the direct effects of structural changes to an individual ion, we show that the significance of these changes is often moderated by the nature of the counter ion of the ionic liquid. We also demonstrate that targeted design of functional groups based on structure-property relations can yield ionic liquids of exceptionally high fluidity.
3D Sn-Based Anodes for Solid State Rechargeable Batteries
Authors: Nurpeissova Arailym , Kalimuldina Gulnur , Bakenov Zhumabay 
Published: December 2020

Recent rapid technological progress in various fields of industry and daily life has been driven by miniaturization of electronics. The devices for various applications such as medical devices, logic and memory circuits, and various sensors have been drastically reduced to smaller dimensions with vastly improved performance. Limited performance of batteries is one of the most critical problems to be tackled for sustainable technological advances and to allow for further development of novel and future technologies.
Lithium-ion batteries (LIBs) exhibit excellent cycle performance and high energy capacity and thus are the best choice to power miniaturized devices. However, the current architecture used in LIBs’ electrodes limits their energy and power densities. Furthermore, safety issues arising from flammable liquid electrolytes and lithium dendrite growth upon cycling still remain as the major challenges for implementation of LIBs in this area. Advanced architectures and materials are needed to design high performance LIBs with increased energy storage capacity per unit volume while maintaining a small footprint area.
A three-dimensional (3D) architecture design of the battery electrodes can remarkably enhance the energy and power densities of conventional LIBs. In this regard, we report a unique 3D architecture anode designed for all-solid battery and fabricated by electrodeposition of ultrathin Ni3Sn4 intermetallic alloy onto a commercially available nickel foam current collector from an aqueous electrolyte. The X-ray diffraction results obtained from three-dimensional electrodes indicated that the main phase of electrodeposited alloys was Ni3Sn4. The designed three-dimensional electrode demonstrated a high discharge capacity of 843,75 mAh g-1 during initial cycles and a stable cycle performance over prolonged cycling. The high surface area of the electrode and short Li+-ions diffusion paths along with suppression of volume expansion provided by the proposed 3D structure and Ni inactive matrix play a key role in improving the performance of the electrode.
Acknowledgements
This work was supported by the project 091019CRP2114 “Three-Dimensional All Solid State Rechargeable Batteries” from Nazarbayev University.

References:

[1] J.M. Tarascon, M. Armand, Issues and challenges facing rechargeable lithium batteries, Nature. 414 (2001) 359–67. https://doi.org/10.1038/35104644.
[2] M.T. McDowell, I. Ryu, S.W. Lee, C. Wang, W.D. Nix, Y. Cui, Studying the kinetics of crystalline silicon nanoparticle lithiation with in situ transmission electron microscopy, Adv. Mater. 24 (2012) 6034–6041. https://doi.org/10.1002/adma.201202744.
Understanding Kinetics of Complex Interfaces in Solid-State Batteries from Multiscale Simulations
Authors: Wood Brandon C. , Heo Tae Wook , Wan Liwen , Dive Aniruddha Mukund , Jana Aniruddha , Shi Rongpei , Kang ShinYoung , Kweon Kyoung , Grieder Andrew , Adelstein Nicole 
Published: December 2020

Developing viable solid-state batteries requires understanding the various chemical and physical processes that occur at homogeneous and heterogeneous solid-solid interfaces. Examples include internal grain boundaries, interphases, and electrode-electrolyte interfaces, each of which can play a key role in determining transport and cycling stability. To explore these impacts in detail, our team has been applying simulations from the atomic scale to the mesoscale, considering the structure, chemistry, and dynamics of the solid-state interfaces. We will provide an overview of these activities as applied to the garnet Li7-xLa3Zr2O12 (LLZO) solid electrolyte system. First, we will show how mesoscale phase-field models can be combined with atomistic simulations of grains and grain boundary regions to predict and assess the transport properties of interface-dominated systems. We apply this framework to determine the operating conditions and microstructural considerations for which grain boundaries appreciably affect diffusion mechanisms and pathways in LLZO. Second, we will show how ab initio simulations are applied to isolate local chemical motifs that act as precursors to interphase formation at the LLZO-cathode interface. Evidence of interdiffusion and structural reorganization at the interface provides clues into possible degradation mechanisms, in addition to impacting interfacial impedance. Overall, the simulation results highlight the importance of considering interfaces in realistic materials descriptions of solid-state batteries, while simultaneously highlighting the possible tunability of microstructure at multiple scales to impact performance.
This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
Improving Cell Resistance and Cycle Life with Solvate/Thiophosphate Hybrid Electrolytes in Lithium Metal and Lithium Sulfur Batteries
Authors: Gewirth Andrew A. , Philip Maria , Shin Minjeong , Madsen Kenneth 
Published: December 2020

Solid electrolytes (SEs) have become a practical option for lithium ion and lithium metal batteries due to their improved safety over commercially available ionic liquids. The most promising of the SEs are the thiophosphates whose excellent ionic conductivities at room temperature are comparable to those of the commercially-utilized ionic liquids. Hybrid solid-liquid electrolytes exhibit higher ionic conductivities than their bare solid electrolyte counterparts due to decreased grain boundary resistance, enhanced interfacial contact with electrodes, and decreased degradation at the interface.
In this study, we evaluate a series of hybrid electrolytes made from a ‘solvate’ electrolyte in both Li-Li symmetric cells and in a full cell with a Li2S cathode relative to their bare Li/SE/Li counterparts. Interestingly, hybrid electrolytes made by combining HFE-modified solvates and SE exhibit all the benefits of the interlayer modified SEs, without the necessity of pellet manufacture. The solvate-integrated cathode layer is additionally beneficial for achieving high active material utilization, maintaining intimate interfacial contact, and providing buffer space for volume contraction and expansion. X-ray tomography measurements show the presence of a buffer layer results in substantially less crack formation. The hybrid Li2S cell exhibited superior cycling performance compared to the solid-state cells in terms of Li2S loading, Li2S utilization, and cycling stability. Finally, we discuss the use of hybrid electrolytes to enable other cathode chemistries.
Highly Ordered Adlayer Formation of Water-Insoluble Nanographenes on Gold Using "Molecular Container"
Authors: Yoshimoto Soichiro , Origuchi Sakura , Sasano Senri , Hashiguchi Shunta , Fukaminato Tsuyoshi , Yoshizawa Michito 
Published: December 2020

Carbon materials such as graphene have been extensively studied for their application in electronic devices,electrocatalysis, and sensors. In contrast, polycyclic aromatic hydrocarbons (PAHs), the so-called nanographenes, are excellent materials for the creation of two-dimensional (2D) nanosheets.[1] The formation of adlayers on electrode surfaces is challenging because PAHs without peripheral substituents are used as 2D molecular templates and applications in conductance enhancement and organic field-effect transistors.[2] However, large PAHs tend to exhibit poor or no solubilities in organic solvents and water.
To overcome this issue, in this study, we employed water-soluble micellar capsules consisting of V-shaped amphiphilic molecules. Characteristic electrochemical behaviors were observed in 0.1 M H2SO4 in the presence of the water-soluble capsules containing PAHs such as dicoronylene. Furthermore, under these conditions, PAHs were released from the capsules, resulting in the formation of a 2D adlayer of PAHs at the electrochemical interface. Finally, using electrochemical scanning tunneling microscopy (EC-STM), we demonstrate that our molecular containers based on the water-soluble molecular capsules allow the facile preparation of 2D PAH adlayers in addition to structurally controlling nanostructure formation on Au surfaces.In particular, dicoronylene molecules formed a highly ordered adlayer with c(4 x 8√3)rect adlattice.[3]

References:
[1] J. Wu, W. Pisula, K. Müllen, Chem. Rev.
2007, 107, 718.
[2] L. Zhang, Y. Cao, N. S. Colella, Y. Liang, J.-L. Brédas, K. N. Houk, A. L. Briseno, Acc. Chem. Res.
2015, 48, 500.
[3] S. Origuchi, M. Kishimoto, M. Yoshizawa, S. Yoshimoto, Angew. Chem., Int. Ed.
2018, 57, 15481.
(Invited) Extended Electrochemical Potential Range Induced By Plasmonic Electronic Excitation
Authors: Murakoshi Kei 
Published: December 2020

Spectroelectrochemistry is powerful tool to investigate electronic sates and geometrical structures of electrified interfaces in-situ under the conditions where photonic and electronic energy conversion functionalities emerge. One can use plasmon-powered processes to expand the ability of the spectroscopy regarding sensitivities in space, time, and energy resolutions. As their characteristics on localization of surface plasmons into molecule scale, huge intensity gradient of electromagnetic field would break the limit of light-matter interactions via the modification of the selection rule of the electronic excitation process. I have discussed about the possibility for the surface-enhanced-Raman scattering (SERS) as the probe to monitor the exotic electronic excitation processes[1-8]. Based on the observation of a small number of molecules at the plasmonic metal nanostructures by SERS, possibilities leading to the future innovative photo-functionalities were demonstrated by showing improved properties at optical manipulation of electrons and molecules, and ions. In this presentation, we will show that the localized surface plasmons of the Au nanodimer structures prepared on defect-free graphene provide highly-confined electromagnetic field to generate holes and electrons of the electrochemical potentials beyond the limit of far field light illumination [7]. Novel non-zero wavevector excitation results in the generation of highly reductive and oxidative powers for electrochemical reactions. The present findings point to a novel approach to breaking the limit of opto-electronic interactions and photochemical reactions using various materials.

References

[1] K. Murakoshi and L. M. Liz-Marzán et al., ACS nano, 14, 28-117 (2019).
[2] T. Konishi et al., J. Am. Chem. Soc. 135, 1009-1014 (2013).
[3] F. Nagasawa et al., J. Phys. Chem. Lett. 5, 14-19 (2014).
[4] M. Takase et al., Nature Photonics, 7, 550-554 (2013)
[5] H. Minamimoto et al., Faraday Discuss. 205, 261-269 (2017).
[6] F. Kato et al., ACS Photonics 5, 788-796 (2018).
[7] J. Zhang et al., Nano Lett. 19, 7887-7894 (2019).
[8] K. Suzuki and X. Li et al., ACS Energy Lett. 5, 1252-1259 (2020).