Electrolyte Dependence of Li+ Transport Mechanisms in Small Molecule Solvents from Classical Molecular Dynamics
As demands on Li-ion battery performance increase, the need for electrolytes with high ionic conductivity and a high Li+ transference number (tLi) becomes crucial to boost power density. Unfortunately, tLi in liquid electrolytes is typically <0.5 due to Li+ migrating via a vehicular mechanism, wh...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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American Chemical Society
2024
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| Online Access: | https://hdl.handle.net/1721.1/155561 |
| _version_ | 1824457980881403904 |
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| author | Crabb, Emily Aggarwal, Abhishek Stephens, Ryan Shao-Horn, Yang Leverick, Graham Grossman, Jeffrey C. |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Crabb, Emily Aggarwal, Abhishek Stephens, Ryan Shao-Horn, Yang Leverick, Graham Grossman, Jeffrey C. |
| author_sort | Crabb, Emily |
| collection | MIT |
| description | As demands on Li-ion battery performance increase, the need for electrolytes with high ionic conductivity and a high Li+ transference number (tLi) becomes crucial to boost power density. Unfortunately, tLi in liquid electrolytes is typically <0.5 due to Li+ migrating via a vehicular mechanism, whereby Li+ diffuses along with its solvation shell, making its diffusivity slower than the counteranion. Designing liquid electrolytes where the Li+ ion diffuses independently of its solvation shell is of significant interest to enhance the transference number. In this work, we elucidate how the properties of the solvent influence the Li+ transport mechanism. Using classical molecular dynamics simulations, we find that a vehicular mechanism can be increasingly preferred with a decreasing solvent viscosity and increasing interaction energy between the solvent and Li+. Thus, a weaker interaction energy can enhance tLi through a solvent-exchange mechanism, ultimately improving Li-ion battery performance. Finally, metadynamics simulations show that in electrolytes where a solvent-exchange mechanism is preferable, the energy barrier to changing the coordination environment of Li+ is much lower than in electrolytes where a vehicular mechanism dominates. |
| first_indexed | 2024-09-23T09:51:29Z |
| format | Article |
| id | mit-1721.1/155561 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2025-02-19T04:18:37Z |
| publishDate | 2024 |
| publisher | American Chemical Society |
| record_format | dspace |
| spelling | mit-1721.1/1555612024-11-21T16:39:42Z Electrolyte Dependence of Li+ Transport Mechanisms in Small Molecule Solvents from Classical Molecular Dynamics Crabb, Emily Aggarwal, Abhishek Stephens, Ryan Shao-Horn, Yang Leverick, Graham Grossman, Jeffrey C. Massachusetts Institute of Technology. Department of Physics Massachusetts Institute of Technology. Research Laboratory of Electronics Massachusetts Institute of Technology. Department of Materials Science and Engineering Massachusetts Institute of Technology. Department of Mechanical Engineering As demands on Li-ion battery performance increase, the need for electrolytes with high ionic conductivity and a high Li+ transference number (tLi) becomes crucial to boost power density. Unfortunately, tLi in liquid electrolytes is typically <0.5 due to Li+ migrating via a vehicular mechanism, whereby Li+ diffuses along with its solvation shell, making its diffusivity slower than the counteranion. Designing liquid electrolytes where the Li+ ion diffuses independently of its solvation shell is of significant interest to enhance the transference number. In this work, we elucidate how the properties of the solvent influence the Li+ transport mechanism. Using classical molecular dynamics simulations, we find that a vehicular mechanism can be increasingly preferred with a decreasing solvent viscosity and increasing interaction energy between the solvent and Li+. Thus, a weaker interaction energy can enhance tLi through a solvent-exchange mechanism, ultimately improving Li-ion battery performance. Finally, metadynamics simulations show that in electrolytes where a solvent-exchange mechanism is preferable, the energy barrier to changing the coordination environment of Li+ is much lower than in electrolytes where a vehicular mechanism dominates. 2024-07-10T16:27:46Z 2024-07-10T16:27:46Z 2024-03-29 2024-07-10T13:12:51Z Article http://purl.org/eprint/type/JournalArticle 1520-6106 1520-5207 https://hdl.handle.net/1721.1/155561 J. Phys. Chem. B 2024, 128, 14, 3427–3441 en 10.1021/acs.jpcb.3c07999 The Journal of Physical Chemistry B Creative Commons Attribution-Noncommercial-ShareAlike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf American Chemical Society Author |
| spellingShingle | Crabb, Emily Aggarwal, Abhishek Stephens, Ryan Shao-Horn, Yang Leverick, Graham Grossman, Jeffrey C. Electrolyte Dependence of Li+ Transport Mechanisms in Small Molecule Solvents from Classical Molecular Dynamics |
| title | Electrolyte Dependence of Li+ Transport Mechanisms in Small Molecule Solvents from Classical Molecular Dynamics |
| title_full | Electrolyte Dependence of Li+ Transport Mechanisms in Small Molecule Solvents from Classical Molecular Dynamics |
| title_fullStr | Electrolyte Dependence of Li+ Transport Mechanisms in Small Molecule Solvents from Classical Molecular Dynamics |
| title_full_unstemmed | Electrolyte Dependence of Li+ Transport Mechanisms in Small Molecule Solvents from Classical Molecular Dynamics |
| title_short | Electrolyte Dependence of Li+ Transport Mechanisms in Small Molecule Solvents from Classical Molecular Dynamics |
| title_sort | electrolyte dependence of li transport mechanisms in small molecule solvents from classical molecular dynamics |
| url | https://hdl.handle.net/1721.1/155561 |
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