Lithium–Sulfur Batteries with Micelle-Structured Electrolytes and Imide-Based Salts

Imide electrolyte salts have received increasing interest in lithium–sulfur battery (LSB) research due to their oxidation capacity, thermal stability, and cycling stability. Although the ionic conductivity of imide electrolytes is moderate, a LSB with exhibits improved charge–discharge (CD) capacity Coulombic efficiency. Here, we applied an effective strategy suppress polysulfide dissolution by using micelle-structured fluorinated ether-based additive (F4EO2) lithium bis(trifluorosulfonyl)imide (LiTFSI) bis(fluorosulfonyl)imide (LiFSI) salts. In contrast LiFSI electrolyte, LiTFSI F4EO2 shows superior performance terms its compatibility (Li)-metal anode, electrochemical high specific discharge ca. 1331 mAh/g sulfur/carbon (S/C) composite//electrolyte//Li-metal configuration at 0.1C. The enhanced increase concentration solution. results demonstrate that solution salt improves suppressing forming favorable passivation layer on Li-metal leading 1221 after 20 cycles 950 100 (for T5FDLiTFSI), respectively, efficiency 99.98% 99.99% CD cycles, respectively.