Synthesis and electrochemical properties of partially fluorinated ether solvents for lithium-sulfur battery electrolytes

Fluorinated ethers have been used as a co-solvent in traditional ether-based electrolytes to suppress the poly sulfide shuttle effect in lithium-sulfur batteries. In this work, five partially fluorinated ether compounds have been synthesized. The key properties, such as viscosity, ionic conductivity and polysulfide solubility of the electrolytes containing these co-solvents have been systematically studied. The electrolyte formulation showed best physical properties was tested in lithium-sulfur coin cells. The new fluoroether-based electrolytes displayed superior electrochemical performance compared to that of the traditional ether-based electrolytes.