Method of purifying lithium hexafluorosphate
AssigneeStella Chemifa Corporation
InventorsHirohisa Kikuyama, Toshirou Fukudome, Masahide Waki, Hirofumi Yazaki
Life of this patent
Estimating the term…
Abstract
A method of purifying lithium hexafluorophosphate that allows to purify lithium hexafluorophosphate, useful as lithium secondary cell electrolyte, organic synthesis medium or the like, to an extremely high purity is provided. Lithium hexafluorophosphate containing harmful impurities such as oxyfluoride, lithium fluoride is purified by adding phosphoric chloride. The purification is performed in the presence of phosphoric chloride and hydrogen fluoride of the quantity equal or superior to the equivalent amount for reacting them, and then by converting lithium fluoride lithium hexafluorophosphate with generated phosphor pentafluoride.
Claims5
A method of purifying lithium hexafluorosphate(LiPF6), wherein the purifying thereof is performed in the presence of phosphoric pentachloride(PCl5) and hydrogen fluoride(HF) of the quantity necessary for producing phosphor pentafluoride(PF5) of the quantity more than necessary for converting lithium fluoride(LiF) and oxyfluoride in a crude lithium hexafluorosphate(LiPF6).
Dependencies are inferred from the claim text.