Physical and electrochemical properties of triethylsulfonium bis(trifluoromethylsulfonyl)imide (S₂₂₂TFSI) ionic liquids with highly concentrated lithium bis(fluorosulfonyl)imide (LiFSI) were studied for application as stable electrolytes over a wide temperature range for Li metal batteries. xLiFSI-(1-x)S₂₂₂TFSI ionic liquids exhibited a wide liquid-phase temperature range between x = 0.1 and 0.7. The ionic conductivity (σ) at 25 °C decreased from 5.6 to 0.27 mS cm⁻¹ as x increased from 0.1 to 0.6, while the lithium transfer number (t_Li) significantly increased with increasing x. The product of σ and t_Li took a maximum value at x = 0.3. Impedance spectra of Li/Li symmetric cells using the ionic liquid electrolytes showed that the interface resistance (R_i) of the Li electrode decreased with increasing x up to 0.5. An increase in R_i with aging time caused by the formation of a solid electrolyte interphase layer was suppressed by increasing LiFSI concentration. Highly concentrated LiFSI ionic liquid at x = 0.6 significantly enhanced the cycling stability of Li deposition-dissolution, indicating that highly concentrated LiFSI ionic liquids from x = 0.3 to 0.6 are promising stable electrolytes with a wide liquid-phase temperature range for Li metal batteries.

研究了具有高浓度双（氟磺酰基）亚胺锂（LiFSI）的三乙基硫双（三氟甲基磺酰基）亚胺（ S ₂₂₂ TFSI）离子液体的物理和电化学性质，以在宽温度范围内用作锂金属电池的稳定电解质。xLiFSI-(1-x)S ₂₂₂ TFSI 离子液体表现出 x = 0.1 和 0.7 之间的宽液相温度范围。随着x 从 0.1 增加到 0.6，25 °C 下的离子电导率 (σ) 从 5.6 降低到 0.27 mS cm ^-1，而锂转移数 ( t _Li ) 随着 x 的增加而显着增加。σ 和t _Li的乘积在 x = 0.3 处取最大值。使用离子液体电解质的 Li/Li 对称电池的阻抗谱表明，Li 电极的界面电阻 ( R _i ) 随着 x 增加到 0.5 而降低。通过增加 LiFSI 浓度，抑制了由固体电解质界面层的形成引起的R _i随老化时间的增加。x = 0.6 的高浓度 LiFSI 离子液体显着增强了 Li 沉积-溶解的循环稳定性，表明 x = 0.3 至 0.6 的高浓度 LiFSI 离子液体是用于锂金属电池的具有宽液相温度范围的稳定电解质。