Method for preparing high-purity annular sulfuric acid ester

Abstract

The invention discloses a method for preparing a high-purity cyclic sulfuric ester. The method comprises the following steps: adopting a method of removing residual raw materials by reaction, namely dissolving the prepared cyclic sulfuric ester crude product in a proper solvent, then adding certain amount of water into the solution, adding a proper amount of potassium permanganate solid in batch under stirring, reducing the generated manganese dioxide and excessive potassium permanganate by using a reducing agent such as sodium bisulfite, and finally treating an organic layer by the steps of water washing, alkali washing, water washing, drying, decompressing to remove the solvent and the like to obtain the high-purity cyclic sulfuric ester. The purified cyclic sulfuric ester is suitable to be used as an electrolyte additive of a lithium secondary battery to improve cycle performance, high-temperature performance and the like of the lithium secondary battery.

Description

technical field [0001] The present invention relates to the purification of high-purity cyclic sulfuric acid ester and the method for preparing high-purity products. In detail, the crude cyclic sulfate is dissolved in a suitable amount of solvent, and in the presence of water, the residual raw material is oxidized with potassium permanganate, and then the manganese dioxide generated is reduced with a reducing agent such as sodium bisulfite and excess potassium permanganate, and the organic layer is washed with water, neutralized, washed with water, dried, and desolvated under reduced pressure to obtain a high-purity cyclic sulfuric acid ester. The cyclic sulfate can be used as an additive to the electrolyte of a lithium secondary battery to improve the cycle performance and high temperature performance of the lithium secondary battery. Background technique [0002] Since the lithium-ion battery produced by Sony Corporation of Japan was launched in early 1991, the lithium-io...

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Problems solved by technology

[0007] The industrial production method of cyclic sulfuric acid ester is usually prepared by oxidation of sodium hypochlorite with cyclic sulfite in the presence of ruthenium trichloride catalyst, and this preparation method usually cannot react completely, and because cyclic sulfurous acid The boiling point of the ester is relatively high, so it is difficult to remove it in the final decompression drying, and the acidity is high, so it cannot be directly used as an electrolyte additive for lithium secondary batteries. It must be purified to reduce the content of impurities and reduce the content of residual acid.