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Zhu C, Pedretti BJ, Kuehster L, Ganesan V, Sanoja GE, Lynd NA. Ionic Conductivity, Salt Partitioning, and Phase Separation in High-Dielectric Contrast Polyether Blends and Block Polymer Electrolytes. Macromolecules 2023. [DOI: 10.1021/acs.macromol.2c02023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Congzhi Zhu
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Benjamin J. Pedretti
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Louise Kuehster
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Venkat Ganesan
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Gabriel E. Sanoja
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Nathaniel A. Lynd
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
- Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States
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2
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Gal JF, Maria PC, Yáñez M, Mó O. Lewis basicity of alkyl carbonates and other esters. The Gutmann Donor Number (DN), a flawed indicator? Boron trifluoride adduct-formation enthalpy, experimentally or computationally determined, as a reliable alternative. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Pedretti BJ, Czarnecki NJ, Zhu C, Imbrogno J, Rivers F, Freeman BD, Ganesan V, Lynd NA. Structure–Property Relationships for Polyether-Based Electrolytes in the High-Dielectric-Constant Regime. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00639] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Benjamin J. Pedretti
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Natalie J. Czarnecki
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Congzhi Zhu
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Jennifer Imbrogno
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Frederick Rivers
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Benny D. Freeman
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Venkat Ganesan
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Nathaniel A. Lynd
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
- Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States
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4
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Imbrogno J, Maruyama K, Rivers F, Baltzegar JR, Zhang Z, Meyer PW, Ganesan V, Aoshima S, Lynd NA. Relationship between Ionic Conductivity, Glass Transition Temperature, and Dielectric Constant in Poly(vinyl ether) Lithium Electrolytes. ACS Macro Lett 2021; 10:1002-1007. [PMID: 35549112 DOI: 10.1021/acsmacrolett.1c00305] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report a partial elucidation of the relationship between polymer polarity and ionic conductivity in polymer electrolyte mixtures comprising a homologous series of nine poly(vinyl ether)s (PVEs) and lithium bis(trifluoromethylsulfonyl)imide. Recent simulation studies have suggested that low dielectric polymer hosts with glass transition temperatures far below ambient conditions are expected to have ionic conductivity limited by salt solubility and dissociation. In contrast, high dielectric hosts are expected to have the potential for high ion solubility but slow segmental dynamics due to strong polymer-polymer and polymer-ion interactions. We report results for PVEs in the low polarity regime with dielectric constants of about 1.3 to 9.0. Ionic conductivity measured for the PVE and salt mixtures ranged from about 10-10 to 10-3 S/cm. In agreement with the predictions from computer simulations, the ionic conductivity increased with dielectric constant and plateaued as the dielectric approached 9.0, comparable to the dielectric constant of the widely used poly(ethylene oxide).
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Affiliation(s)
| | - Kazuya Maruyama
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | | | | | | | | | | | - Sadahito Aoshima
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
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Yang G, Ivanov IN, Ruther RE, Sacci RL, Subjakova V, Hallinan DT, Nanda J. Electrolyte Solvation Structure at Solid-Liquid Interface Probed by Nanogap Surface-Enhanced Raman Spectroscopy. ACS NANO 2018; 12:10159-10170. [PMID: 30226745 DOI: 10.1021/acsnano.8b05038] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Understanding the fundamental factors that drive ion solvation structure and transport is key to design high-performance, stable battery electrolytes. Reversible ion solvation and desolvation are critical to the interfacial charge-transfer process across the solid-liquid interface as well as the resulting stability of the solid electrolyte interphase. Herein, we report the study of Li+ salt solvation structure in aprotic solution in the immediate vicinity (∼20 nm) of the solid electrode-liquid interface using surface-enhanced Raman spectroscopy (SERS) from a gold nanoparticle (Au NP) monolayer. The plasmonic coupling between Au NPs produces strong electromagnetic field enhancement in the gap region, leading to a 5 orders of magnitude increase in Raman intensity for electrolyte components and their mixtures namely, lithium hexafluorophosphate, fluoroethylene carbonate, ethylene carbonate, and diethyl carbonate. Further, we estimate and compare the lithium-ion solvation number derived from SERS, standard Raman spectroscopy, and Fourier transform infrared spectroscopy experiments to monitor and ascertain the changes in the solvation shell diameter in the confined nanogap region where there is maximum enhancement of the electric field. Our findings provide a multimodal spectroscopic approach to gain fundamental insights into the molecular structure of the electrolyte at the solid-liquid interface.
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Affiliation(s)
- Guang Yang
- Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Ilia N Ivanov
- Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Rose E Ruther
- Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Robert L Sacci
- Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Veronika Subjakova
- Department of Nuclear Physics and Biophysics , Comenius University , Mlynska dolina F1 , Bratislava 84248 , Slovakia
| | - Daniel T Hallinan
- Department of Chemical and Biomedical Engineering , Florida A&M University-Florida State University College of Engineering , 2525 Pottsdamer Street , Tallahassee , Florida 32310 , United States
| | - Jagjit Nanda
- Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
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6
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Borodin O, Ren X, Vatamanu J, von Wald Cresce A, Knap J, Xu K. Modeling Insight into Battery Electrolyte Electrochemical Stability and Interfacial Structure. Acc Chem Res 2017; 50:2886-2894. [PMID: 29164857 DOI: 10.1021/acs.accounts.7b00486] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Electroactive interfaces distinguish electrochemistry from chemistry and enable electrochemical energy devices like batteries, fuel cells, and electric double layer capacitors. In batteries, electrolytes should be either thermodynamically stable at the electrode interfaces or kinetically stable by forming an electronically insulating but ionically conducting interphase. In addition to a traditional optimization of electrolytes by adding cosolvents and sacrificial additives to preferentially reduce or oxidize at the electrode surfaces, knowledge of the local electrolyte composition and structure within the double layer as a function of voltage constitutes the basis of manipulating an interphase and expanding the operating windows of electrochemical devices. In this work, we focus on how the molecular-scale insight into the solvent and ion partitioning in the electrolyte double layer as a function of applied potential could predict changes in electrolyte stability and its initial oxidation and reduction reactions. In molecular dynamics (MD) simulations, highly concentrated lithium aqueous and nonaqueous electrolytes were found to exclude the solvent molecules from directly interacting with the positive electrode surface, which provides an additional mechanism for extending the electrolyte oxidation stability in addition to the well-established simple elimination of "free" solvent at high salt concentrations. We demonstrate that depending on their chemical structures, the anions could be designed to preferentially adsorb or desorb from the positive electrode with increasing electrode potential. This provides additional leverage to dictate the order of anion oxidation and to effectively select a sacrificial anion for decomposition. The opposite electrosorption behaviors of bis(trifluoromethane)sulfonimide (TFSI) and trifluoromethanesulfonate (OTF) as predicted by MD simulation in highly concentrated aqueous electrolytes were confirmed by surface enhanced infrared spectroscopy. The proton transfer (H-transfer) reactions between solvent molecules on the cathode surface coupled with solvent oxidation were found to be ubiquitous for common Li-ion electrolyte components and dependent on the local molecular environment. Quantum chemistry (QC) calculations on the representative clusters showed that the majority of solvents such as carbonates, phosphates, sulfones, and ethers have significantly lower oxidation potential when oxidation is coupled with H-transfer, while without H-transfer their oxidation potentials reside well beyond battery operating potentials. Thus, screening of the solvent oxidation limits without considering H-transfer reactions is unlikely to be relevant, except for solvents containing unsaturated functionalities (such as C═C) that oxidize without H-transfer. On the anode, the F-transfer reaction and LiF formation during anion and fluorinated solvent reduction could be enhanced or diminished depending on salt and solvent partitioning in the double layer, again giving an additional tool to manipulate the order of reductive decompositions and interphase chemistry. Combined with experimental efforts, modeling results highlight the promise of interphasial compositional control by either bringing the desired components closer to the electrode surface to facilitate redox reaction or expelling them so that they are kinetically shielded from the potential of the electrode.
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Affiliation(s)
- Oleg Borodin
- Electrochemistry
Branch, Sensors and Electron Devices Directorate, US Army Research Laboratory, 2800 Powder Mill Rd., Adelphi, Maryland 20783, United States
| | - Xiaoming Ren
- Electrochemistry
Branch, Sensors and Electron Devices Directorate, US Army Research Laboratory, 2800 Powder Mill Rd., Adelphi, Maryland 20783, United States
| | - Jenel Vatamanu
- Electrochemistry
Branch, Sensors and Electron Devices Directorate, US Army Research Laboratory, 2800 Powder Mill Rd., Adelphi, Maryland 20783, United States
| | - Arthur von Wald Cresce
- Electrochemistry
Branch, Sensors and Electron Devices Directorate, US Army Research Laboratory, 2800 Powder Mill Rd., Adelphi, Maryland 20783, United States
| | - Jaroslaw Knap
- Simulation Sciences Branch, RDRL-CIH-C, US Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005-5066, United States
| | - Kang Xu
- Electrochemistry
Branch, Sensors and Electron Devices Directorate, US Army Research Laboratory, 2800 Powder Mill Rd., Adelphi, Maryland 20783, United States
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7
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Pollard TP, Beck TL. Structure and polarization near the Li+ ion in ethylene and propylene carbonates. J Chem Phys 2017; 147:161710. [DOI: 10.1063/1.4992788] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Travis P. Pollard
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, USA
| | - Thomas L. Beck
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, USA
- Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221, USA
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8
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Frisco S, Liu DX, Kumar A, Whitacre JF, Love CT, Swider-Lyons KE, Litster S. Internal Morphologies of Cycled Li-Metal Electrodes Investigated by Nano-Scale Resolution X-ray Computed Tomography. ACS APPLIED MATERIALS & INTERFACES 2017; 9:18748-18757. [PMID: 28485578 DOI: 10.1021/acsami.7b03003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
While some commercially available primary batteries have lithium metal anodes, there has yet to be a commercially viable secondary battery with this type of electrode. Research prototypes of these cells typically exhibit a limited cycle life before dendrites form and cause internal cell shorting, an occurrence that is more pronounced during high-rate cycling. To better understand the effects of high-rate cycling that can lead to cell failure, we use ex situ nanoscale-resolution X-ray computed tomography (nano-CT) with the aid of Zernike phase contrast to image the internal morphologies of lithium metal electrodes on copper wire current collectors that have been cycled at low and high current densities. The Li that is deposited on a Cu wire and then stripped and deposited at low current density appears uniform in morphology. Those cycled at high current density undergo short voltage transients to >3 V during Li-stripping from the electrode, during which electrolyte oxidation and Cu dissolution from the current collector may occur. The effect of temperature is also explored with separate cycling experiments performed at 5 and 33 °C. The resulting morphologies are nonuniform films filled with voids that are semispherical in shape with diameters ranging from hundreds of nanometers to tens of micrometers, where the void size distributions are temperature-dependent. Low-temperature cycling elicits a high proportion of submicrometer voids, while the higher-temperature sample morphology is dominated by voids larger than 2 μm. In evaluating these morphologies, we consider the importance of nonidealities during extreme charging, such as electrolyte decomposition. We conclude that nano-CT is an effective tool for resolving features and aggressive cycling-induced anomalies in Li films in the range of 100 nm to 100 μm.
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Affiliation(s)
- Sarah Frisco
- Department of Materials Science and Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Danny X Liu
- Chemistry Division, U.S. Naval Research Laboratory , Washington, District of Columbia 20375, United States
| | - Arjun Kumar
- Department of Mechanical Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Jay F Whitacre
- Department of Materials Science and Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Corey T Love
- Chemistry Division, U.S. Naval Research Laboratory , Washington, District of Columbia 20375, United States
| | - Karen E Swider-Lyons
- Chemistry Division, U.S. Naval Research Laboratory , Washington, District of Columbia 20375, United States
| | - Shawn Litster
- Department of Mechanical Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
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Zahn R, Lagadec MF, Hess M, Wood V. Improving Ionic Conductivity and Lithium-Ion Transference Number in Lithium-Ion Battery Separators. ACS APPLIED MATERIALS & INTERFACES 2016; 8:32637-32642. [PMID: 27934143 DOI: 10.1021/acsami.6b12085] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The microstructure of lithium-ion battery separators plays an important role in separator performance; however, here we show that a geometrical analysis falls short in predicting the lithium-ion transport in the electrolyte-filled pore space. By systematically modifying the surface chemistry of a commercial polyethylene separator while keeping its microstructure unchanged, we demonstrate that surface chemistry, which alters separator-electrolyte interactions, influences ionic conductivity and lithium-ion transference number. Changes in separator surface chemistry, particularly those that increase lithium-ion transference numbers can reduce voltage drops across the separator and improve C-rate capability.
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Affiliation(s)
- Raphael Zahn
- Laboratory for Nanoelectronics, Department of Information Technology and Electrical Engineering, Eidgenoessische Technische Hochschule Zurich , 8092 Zurich, Switzerland
| | - Marie Francine Lagadec
- Laboratory for Nanoelectronics, Department of Information Technology and Electrical Engineering, Eidgenoessische Technische Hochschule Zurich , 8092 Zurich, Switzerland
| | - Michael Hess
- Laboratory for Nanoelectronics, Department of Information Technology and Electrical Engineering, Eidgenoessische Technische Hochschule Zurich , 8092 Zurich, Switzerland
| | - Vanessa Wood
- Laboratory for Nanoelectronics, Department of Information Technology and Electrical Engineering, Eidgenoessische Technische Hochschule Zurich , 8092 Zurich, Switzerland
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