Preparation method of high-temperature-resistant low-resistivity lithium ion battery diaphragm

Abstract

The invention relates to a preparation method of a high-temperature-resistant low-resistivity lithium ion battery diaphragm and belongs to the technical field of battery diaphragms. The high-temperature-resistant low-resistivity lithium ion battery diaphragm comprises a base film and a coating slurry layer applied to one lateral end surface or two lateral end surfaces of the base film, the coating slurry layer is made of ceramic slurry or graphene-modified ceramic slurry, and the coating slurry layer on at least one of the two lateral end surfaces of the base film is made from graphene-modified ceramic slurry; the preparation of the diaphragm comprises the steps of preparing graphene-modified ceramic slurry, pretreating a base film and coating and drying; sodium polyacrylate, ammonia water, alcohol, graphene and waterborne acrylic emulsion as well as sodium carboxymethyl cellulose solution are added in sequence during preparation of the graphene-modified ceramic slurry, the slurry that is obtained has stable properties and is as advantageous as the ceramic slurry and graphene material, a battery diaphragm with the base film coated with the slurry has low shrinkage and high safety, battery charging speed is high, and the diaphragm is suitable the industries requiring high-temperature operation and quick-charge batteries, such as electric vehicles.

Description

technical field [0001] The invention belongs to the technical field of battery separators, and in particular relates to a preparation method of a high-temperature-resistant and low-resistivity lithium-ion battery separator. Background technique [0002] The basic function of the battery separator in a lithium battery is to separate the positive and negative electrodes, and to absorb the electrolyte to allow lithium ions to pass through. 3C products include computers (Computer), communications (Communication) and consumer electronics (ConsumerElectronics), which are the main fields of application of lithium batteries. For lithium batteries of 3C products, only PP separators and PE separators are used, and their performance can be compared. nice to meet. However, with the continuous development of electric vehicles, the performance of lithium batteries must be further improved to meet the requirements of electric vehicles. Lithium batteries have more stringent requirements. ...

AI Technical Summary

Problems solved by technology

At present, the high temperature resistance and heat-resistant shrinkage of ceramic coated separators cannot meet the requirements under certain temperature conditions. Graphene modified ceramic coated separators are used to improve the heat-resistant stability and heat-resistant shrinkage of lithium battery separators. It has been greatly improved, and can greatly increase the charging and discharging speed of the battery, and increase the specific energy of the battery, and the graphene-modified diaphragm battery prepared by a special process can achieve high-temperature closed cells, preventing further reaction of the battery and preventing the overheating of the battery. A series of hazards, the charging and discharging function of the battery is automatically restored at room temperature, and the market competitiveness is greatly improved. However, there is no relatively mature method for preparing the graphene-modified coating separator in the prior art.

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