Lithium Speciation in the LiPF6/PC Electrolyte Studied by Two-Dimensional Heteronuclear Overhauser Enhancement and Pulse-Field Gradient Diffusometry NMR
| Autor: | Narayanan Chandrakumar, Vikas Bajpai Awantika Singh Sunil Kumar, R. Ravikanth Reddy, Subramanian Ganapathy, B. V. N. Phani Kumar, Swaminathan Sivaram, C. V. Avadhani |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Analytical chemistry Solvation 02 engineering and technology Electrolyte Lithium hexafluorophosphate 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Dissociation (chemistry) 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Ion Solvent chemistry.chemical_compound General Energy chemistry Heteronuclear molecule Physical and Theoretical Chemistry 0210 nano-technology Spectroscopy |
| Zdroj: | The Journal of Physical Chemistry C. 123:9661-9672 |
| ISSN: | 1932-7455 1932-7447 |
| Popis: | Electrolytic dissociation of lithium hexafluorophosphate (LiPF6) in the nonaqueous cyclic propylene carbonate (PC) has been investigated in the wide range of concentration (0.05–3.5 M) by 7Li solution-state nuclear magnetic resonance (NMR) spectroscopy. Two-dimensional heteronuclear Overhauser enhancement spectroscopy NMR experiments have not only enabled the cation solvation and ion-pairing to be directly monitored but additionally evidence anion–solvent interaction at higher concentrations (>1.2 M) of the PC electrolyte. Preliminary analysis of kinetic nOe data has been made to determine site-dependent cross-relaxation rates for the spatial interaction of the solvent with the Li+ cation and the PF6– anion. The concentration dependence of the 7Li NMR self-diffusion coefficient (Dself), determined using very strong pulsed magnetic field gradients (∼1700 Gauss/cm), depicts two breaks to mark the solvation and ion-pairing events in a distinct manner. This in turn has aided the determination of solvent coord... |
| Databáze: | OpenAIRE |
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