Enhanced safety of sulfone-based electrolytes for lithium-ion batteries: broadening electrochemical window and enhancing thermal stability

By introducing 2 wt.% of triphenylphosphine oxide (TPPO) as a film-forming agent into a sulfone-based electrolyte containing 1 mol L -1 of lithium difluoro (oxalate) borate (LiDFOB), the electrochemical window of the lithium-ion battery electrolyte can be expended to 4.63 V. Additionally, this addition significantly enhances the thermal stability of the electrolyte.