Lithium hydroxide monohydrate, preparation method and application thereof, lithium ion battery positive electrode material and lithium ion battery

Abstract

The present disclosure relates to lithium hydroxide monohydrate, a preparation method and application thereof, a lithium ion battery positive electrode material and a lithium ion battery. The lithiumhydroxide monohydrate has a particle size of 100-380 nm, and by weight, the content of Cu in the lithium hydroxide monohydrate is less than 1ppm, the content of Cr is less than 1ppm, the content of Niis less than 2ppm, the content of Zn is less than 2ppm, and the content of Fe is less than 4 ppm. The lithium hydroxide monohydrate has low magnetic element content, and can improve the service lifeof the lithium ion battery and reduce the self-discharge effect of the lithium ion battery when being used for preparing the lithium ion battery positive electrode material.

Description

technical field [0001] The present disclosure relates to the technical field of membrane separation, in particular to lithium hydroxide monohydrate, its preparation method and application, lithium ion battery cathode material and lithium ion battery. Background technique [0002] As an important industrial raw material, lithium hydroxide monohydrate is widely used in chemical industry, national defense, aerospace and energy storage. The lithium-based grease produced by lithium hydroxide monohydrate has the advantages of anti-oxidation, good fire resistance, wide applicable temperature range, and stable cycle performance. In the field of national defense, it can be used as a heat carrier for nuclear reactors and a protective agent for metal surfaces. In the field of aerospace, lithium hydroxide monohydrate can be used to purify the air in submarines and as a breathing mask for aviation pilots. In particular, with the rapid development of the lithium battery industry, lithiu...

AI Technical Summary

Problems solved by technology

However, because most of the salt lake brine in my country has a high magnesium-lithium ratio, it is very difficult to mine. For example, the document CN107720785A discloses a method for preparing lithium hydroxide based on membrane separation technology. In this document, the diluted old brine is directly used as nanofiltration Stock solution, due to the high concentration of Mg ions in the old salt lake brine (70000-100000ppm), it takes a lot of pure water to dilute the brine (more than 10 times the volume of brine) to achieve the concentration of divalent ions in the nanofiltration stock solution It is lower than the requirement of 8000ppm, which not only greatly increases the amount of water to be treated in nanofiltration and subsequent processes, resulting in large-scale equipment and high equipment costs, but also due to divalent and The content of multivalent ions is high, which leads to the unsatisfactory effect of impurity removal in the nanofiltration membrane separation process, which is not conducive to obtaining lithium hydroxide monohydrate with low magnetic content.

Secondly, the patented process needs to use hydrochloric acid to adjust the acidity, which is not conducive to environmental protection

In addition, the ion exchange section of this patent is located after the nanofiltration process, which not only increases the amount of resin used, but also increases the corresponding concentration of impurity ions in the subsequent lithium enrichment and concentration process, which is very likely to cause final The content of impurity ions including magnetic elements in the product lithium hydroxide monohydrate is relatively high

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