METHOD OF PURIFYING LITHIUM HEXAFLUOROPHOSPHATE

摘要

A method of purifying lithium hexafluorophosphate, useful as an electrolyte for a secondary lithium battery or a catalyst for organic synthesis, to an extremely high purity. Phosphorus pentachloride is added to the lithium hexafluorophosphate to be purified which contains harmful impurities such as oxyfluorides and lithium fluoride. Hydrofluoric acid is further added to the lithium hexafluorophosphate in at least an equivalent amount based on the phosphorus pentachloride, and is reacted with the pentachloride to yield phosphorus pentafluoride, with which the lithium fluoride is converted to lithium hexafluorophosphate to conduct purification.