High-efficiency purifying device and method for short-path distillation of lithium bis(fluorosulfonyl)imide

Abstract

The invention discloses a high-efficiency purifying device and method for short-path distillation of lithium bis(fluorosulfonyl)imide short-path distillation. The device comprises a working platform, crystallization mechanisms, a control console, a reaction filter, a first feeder, a second feeder, mixed heating pipes, a third feeder and short-path distillers; the two crystallization mechanisms are arranged at the front end and the rear end of the right side of the working platform correspondingly; the two mixed heating pipes are arranged on the front side and the rear side of the top end of the working platform through supports correspondingly; and the two short-path distillers are respectively arranged at the top end of the working platform and are positioned at the right lower parts of the front and rear mixed heating pipes. The lithium bis(fluorosulfonyl)imide short-path distillation efficient purification device can realize lithium bis(fluorosulfonyl)imide short-path distillation integrated line production, is high in automation degree, automatically treats water vapor adsorbed on the inner wall in the reaction process in the process of separating out crystals from a lithium bis(fluorosulfonyl)imide intermediate product, and is long in crystallization time, and the processing efficiency of the lithium bis(fluorosulfonyl)imide is improved.

Description

technical field [0001] The invention relates to the technical field of lithium-ion batteries, in particular to a short-path distillation high-efficiency purification device for lithium bisfluorosulfonimide and a purification method thereof. Background technique [0002] Lithium-ion batteries are widely used in many fields such as mobile phones, notebook computers, small charging systems, and electric vehicles because of their large energy density, high operating voltage, and long cycle life. The continuous development is still expanding. The electrolyte in the existing lithium ion battery is lithium hexafluorophosphate product. This product has the advantages of high conductivity, but at the same time, it also has disadvantages such as poor thermal stability, harsh preparation process, and poor high and low temperature performance. Therefore, researchers are also continuing to develop new electrolytes for new lithium-ion batteries to improve the overall performance of lithiu...

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Problems solved by technology

[0002] Lithium-ion batteries are widely used in many fields such as mobile phones, notebook computers, small charging systems, electric vehicles, etc. because of their advantages such as large energy density, high working voltage, and long cycle life, and their application fields are changing with society. The continuous development is still expanding. The electrolyte in the existing lithium-ion battery is lithium hexafluorophosphate product. This product has the advantages of high conductivity, but at the same time, it also has disadvantages such as poor thermal stability, harsh preparation process, and poor high and low temperature performance. Therefore, researchers are also continuing to develop new electrolytes for new lithium-ion batteries to improve the overall performance of lithium-ion batteries. Among them, lithium bistrifluoromethylsulfonylimide (LiTFSI) has a large anion radius and is easy to dissociate. Lithium ions can be released, which can increase the conductivity, and the product has good thermal stability, but the product will corrode the aluminum sheet of the positive electrode current collector at a potential of 3.7V (Li+ / Li), which in turn affects the electrolyte. Applications in lithium-ion batteries have been studied. Lithium-ion battery electrolytes containing F—P bond anions can significantly reduce the corrosion of the electrolyte on the current collector. Therefore, lithium bisfluorosulfonyl imide (LiFSI) is due to its good structural stability and Excellent properties such as electrochemical properties have been widely favored by researchers in both academia and industry;

[0003] In the prior art field, during the high-efficiency purification process of short-path distillation of lithium bisfluorosulfonyl imide, during the crystallization process of the intermediate product of lithium bisfluorosulfonyl imide, water vapor adheres to the inner wall of the reaction tank and reflows into the middle under the action of gravity. In the product, the overall crystal precipitation time is longer, which affects the processing efficiency of lithium bisfluorosulfonyl imide

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