Manufacturing method for lithium hexafluoro phosphate

Abstract

A method of preparing lithium hexafluoro phosphate (LiPF6) using phosphorous pentachloride (PCl5), lithium chloride (LiCl), and hydrogen fluoride (HF) as raw materials. The method includes the steps of: (a) reacting the phosphorous pentafluoride with the hydrogen fluoride to prepare phosphorous pentafluoride (PF5), and (b) reacting the phosphorous pentafluoride with the lithium chloride in a hydrogen fluoride to prepare the lithium hexafluoro phosphate. Also, in this method, anhydrous hydrogen fluoride, from which moisture was removed by treating with F2 gas, is used in the steps (a) and (b), and the step (b) further comprises contacting the reaction system of the step (b) with F2 gas. Accordingly, as the method adopts relatively cheap raw materials, such as PCl5, LiCl and the like, while a highly pure F2 obtained by an electrolysis is used in the reaction system, it has an advantage in that it enables lithium hexafluoro phosphate (LiPF6) to be prepared at a high yield and purity.

Dependencies are inferred from the claim text.