Additives for Stabilizing LiPF[sub 6]-Based Electrolytes Against Thermal Decomposition

Thermal stability of lithium-ion battery electrolytes composed of in a mixture of organic carbonates was probed. Generation of via the thermal dissociation of is the primary source of thermal decomposition. It was found that the addition of low concentrations (3-12%) of Lewis basic additives provides a dramatic increase in the thermal stability of the electrolyte. The increased stability is linked to the formation of base: complexes which reversibly sequester , preventing the decomposition of the electrolyte. Lewis bases investigated include pyridine, hexamethoxycyclotriphosphazene, and hexamethylphosphoramide. Our results can serve as a valuable model for stabilizing organic electrolytes against thermal decomposition initiated by Lewis acids.