| Autor: |
Liu, Xu, Zarrabeitia, Maider, Mariani, Alessandro, Gao, Xinpei, Schütz, Hanno Maria, Fang, Shan, Bizien, Thomas, Elia, Giuseppe Antonio, Passerini, Stefano |
| Předmět: |
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| Zdroj: |
Small Methods; Jul2021, Vol. 5 Issue 7, p1-13, 13p |
| Abstrakt: |
FSI−‐based ionic liquids (ILs) are promising electrolyte candidates for long‐life and safe lithium metal batteries (LMBs). However, their practical application is hindered by sluggish Li+ transport at room temperature. Herein, it is shown that additions of bis(2,2,2‐trifluoroethyl) ether (BTFE) to LiFSI‐Pyr14FSI ILs can effectively mitigate this shortcoming, while maintaining ILs′ high compatibility with lithium metal. Raman spectroscopy and small‐angle X‐ray scattering indicate that the promoted Li+ transport in the optimized electrolyte, [LiFSI]3[Pyr14FSI]4[BTFE]4 (Li3Py4BT4), originates from the reduced solution viscosity and increased formation of Li+‐FSI− complexes, which are associated with the low viscosity and non‐coordinating character of BTFE. As a result, Li/LiFePO4 (LFP) cells using Li3Py4BT4 electrolyte reach 150 mAh g−1 at 1 C rate (1 mA cm−2) and a capacity retention of 94.6% after 400 cycles, revealing better characteristics with respect to the cells employing the LiFSI‐Pyr14FSI (operate only a few cycles) and commercial carbonate (80% retention after only 218 cycles) electrolytes. A wide operating temperature (from −10 to 40 °C) of the Li/Li3Py4BT4/LFP cells and a good compatibility of Li3Py4BT4 with LiNi0.5Mn0.3Co0.2O2 (NMC532) are demonstrated also. The insight into the enhanced Li+ transport and solid electrolyte interphase characteristics suggests valuable information to develop IL‐based electrolytes for LMBs. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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