Lithium bis(fluorosulfonyl)imide (LiFSI) is one of the most promising lithium salts for use in lithium-ion batteries owing to its high ionic conductivity, high solubility in organic solvents, and excellent solid electrolyte interphase (SEI)-forming ability. In this study, we developed an ethylene carbonate (EC)-free electrolyte comprising LiFSI and sulfolane (SL) (LiFSI/SL). LiFSI/SL exhibits ideal Walden electrolyte behavior and crystallinity gap phenomena as well as reversible lithium intercalation into a graphite electrode. LiCoO₂/graphite full-cells containing the new electrolyte show superior cycle stabilities at room and high temperature compared to those with conventional LiPF₆/EC-based electrolytes. For example, after 200 cycles at 60 °C followed by 200 cycles at 70 °C, a cell with 1.5 mol dm⁻³ LiFSI/SL delivers a discharge capacity of 1.12 mAh, while that with 1.0 mol dm⁻³ LiPF₆/EC/EMC delivers a discharge capacity of only 0.84 mAh under the same conditions. The enhanced performance of batteries with LiFSI/SL can be attributed to the effective SEI derived from LiFSI.

双（氟磺酰基）酰亚胺锂（LiFSI）由于其高离子电导率，在有机溶剂中的高溶解性以及出色的固体电解质相间（SEI）形成能力，是最有希望用于锂离子电池的锂盐之一。在这项研究中，我们开发了包含LiFSI和环丁砜（SL）（LiFSI / SL）的不含碳酸亚乙酯（EC）的电解质。LiFSI / SL表现出理想的Walden电解质性能和结晶间隙现象，以及可逆的锂嵌入石墨电极中。与传统的LiPF ₆相比，包含新电解质的LiCoO ₂ /石墨全电池在室温和高温下显示出优异的循环稳定性。/ EC型电解液。例如，在60°C下200次循环后，再在70°C下200次循环后，具有1.5 mol dm ^-3 LiFSI / SL的电池的放电容量为1.12 mAh，而具有1.0 mol dm ^-3 LiPF ₆ / EC的电池的放电容量/ EMC在相同条件下的放电容量仅为0.84 mAh。具有LiFSI / SL的电池性能的增强可归因于源自LiFSI的有效SEI。