| 1. |
- Drvarič Talian, Sara, et al.
(författare)
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Fluorinated Ether Based Electrolyte for High-Energy Lithium-Sulfur Batteries: Li+ Solvation Role behind Reduced Polysulfide Solubility
- 2017
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Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 1520-5002 .- 0897-4756. ; 29:23, s. 10037-10044
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Tidskriftsartikel (refereegranskat)abstract
- By employing new electrolytes, the polysulfide shuttle phenomenon, one of the main problems of lithium-sulfur (Li-S) batteries, can be significantly reduced. Here we present excellent Coulombic efficiencies as well as adequate performance of high-energy Li-S cells by the use of a fluorinated ether (TFEE) based electrolyte at low electrolyte loading. The observed altered discharge profile was investigated both by electrochemical experiments and an especially tailored COSMO-RS computational approach, while the details of the discharge mechanism were elucidated by two operando techniques: XANES and UV-vis spectroscopy. A significant decrease of polysulfide solubility compared to tetraglyme is due to different Li+ solvation mode.
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| 2. |
- Flores, Eibar, 1990, et al.
(författare)
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Solvation structure in dilute to highly concentrated electrolytes for lithium-ion and sodium-ion batteries
- 2017
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Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686. ; 233, s. 134-141
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Tidskriftsartikel (refereegranskat)abstract
- The solvation structure of several lithium and sodium based electrolytes are explored as a function of salt concentration over a wide range via a detailed PM7 computational study. The cation coordination shells are found to be well-defined and solvent rich for dilute electrolytes, while disordered and anion rich for the more concentrated electrolytes. The Na-based electrolytes display larger cation coordination shells with a more pronounced presence of fluorine as compared to the Li-based electrolytes. The origins of the structural differences are discussed as well as their consequences for properties of battery electrolytes and battery usage-especially targeting the current large interest in highly concentrated electrolytes.
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| 3. |
- Jeschke, Steffen, 1986, et al.
(författare)
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Predicting the Solubility of Sulfur: A COSMO-RS-Based Approach to Investigate Electrolytes for Li-S Batteries
- 2017
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Ingår i: Chemistry - A European Journal. - : Wiley. - 1521-3765 .- 0947-6539. ; 23:38, s. 9130-9136
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Tidskriftsartikel (refereegranskat)abstract
- Lithium-sulfur (Li-S) batteries are, in theory, considering their basic reactions, very promising from a specific energy density point of view, but have poor power rate capabilities. The dissolution of sulfur from the C/S cathode in the electrolyte is a rate-determining and crucial step for the functionality. To date, time-consuming experimental methods, such as HPLC/UV, have been used to quantify the corresponding solubilities. Here, we use a computational fluid-phase thermodynamics approach, the conductor-like screening model for real solvents (COSMO-RS), to compute the solubilities of sulfur in different binary and ternary electrolytes. By using both explicit and implicit solvation approaches for lithium bistrifluoromethanesulfonimidate (LiTFSI)-containing electrolytes, a deviation of
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