Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7726222 | Journal of Power Sources | 2018 | 10 Pages |
Abstract
Herein, we report the results of a detailed study on the use of different Li imide salts (LiTFSI, LiFSI, and LiFTFSI) as electrolyte additives for lithium-ion batteries. The introduction of lithium imide salts in the electrolyte is shown to considerably improve the first cycle coulombic efficiency and the long-term cycling stability of graphite/LiFePO4 cells. Using LiTFSI, a capacity fading of only â¼2% occurred over 600 cycles while the control cell with the state-of-the-art additive (VC) lost â¼20% of the initial capacity at 20 °C. The results of the XPS and impedance spectroscopy measurements of graphite electrodes show that, after the formation cycle, the SEI obtained in the presence of imide salts is thinner, contains more LiF and is less resistive than that obtained using VC. Despite the beneficial effect of the imide salts on the lithium-ion cell performance, a slightly reduced thermal stability of the SEI is observed.
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Varvara Sharova, Arianna Moretti, Thomas Diemant, Alberto Varzi, R.Jürgen Behm, Stefano Passerini,