Method for preparing lithium ion battery diaphragm

A lithium ion battery and separator technology, applied in the field of preparation of lithium ion battery separator, can solve the problems of separator battery short circuit, battery failure, battery short circuit, etc., and achieve the effects of prolonging service life, preventing shrinkage and improving safety.

Inactive Publication Date: 2012-04-18
BAODING SHANHE RIYUE INDAL +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the production process or use of lithium-ion batteries, the internal short circuit of the battery is often caused by the puncture of the diaphragm; in addition, the diaphragm material will shrink when the temperature is high, and the shrinkage of the diaphragm can also cause the internal short circuit of the battery, resulting in battery failure, and may It will cause an explosion, which will bring great safety problems

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] 1. First prepare the diaphragm on the negative electrode sheet

[0022] (1) Dissolve about 5 grams of polyvinylidene fluoride (PVDF) in 50 grams of N-methylpyrrolidone (NMP), add 1 g of nano-aluminum nitride, ball mill for 3 hours, and mix well to obtain a slurry;

[0023] (2) Spray the ball-milled slurry on the surface of the negative electrode with a thickness of about 20 microns, and then pass the sprayed negative electrode through a box with a relative humidity of 85%~95% for about 3 minutes;

[0024] (3) After taking the negative electrode out of the box, immediately bake it at 90~95°C until the moisture in the coating is less than 200ppm, and a separator is formed on the surface of the negative electrode.

[0025] 2. Prepare the soft-packed lithium-ion battery according to the existing conventional technology with the negative electrode sheet covered with the separator and the positive electrode sheet.

[0026] The lithium-ion battery is tested as follows:

[00...

Embodiment 2

[0031] 1. First prepare the diaphragm on the positive electrode sheet

[0032] (1) Dissolve about 3 g of polyvinylidene fluoride (PVDF) in 40 g of dimethylacetamide, add 2 g of nano-titanium oxide, stir magnetically at 40°C for 4 hours, and mix well to obtain a slurry;

[0033] (2) Spray the prepared slurry on the surface of the positive electrode at 60°C with a spray thickness of about 15 microns, and then pass the sprayed negative electrode through a box with a relative humidity of 85% to 95% for about 3 minutes;

[0034] (3) After taking the negative electrode out of the box, immediately bake it at 90~95°C. After baking, the moisture in the coating is required to be less than 200ppm.

[0035] 2. Prepare the soft-packed lithium-ion battery according to the existing conventional technology with the negative electrode sheet covered with the separator and the positive electrode sheet.

[0036] The above-mentioned lithium-ion battery is tested as follows:

[0037] 1. High temp...

Embodiment 3

[0041] 1. First prepare the diaphragm on the negative electrode sheet

[0042] (1) Dissolve about 5 g of polyvinylidene fluoride (PVDF) in 70 g of dimethylformamide, add 3 g of nano-alumina, stir magnetically at 45 ° C for 4 hours, and mix well to obtain a slurry;

[0043] (2) Spray the prepared slurry on the surface of the negative electrode sheet at 40~60°C, the spray thickness is about 25 microns, and then pass the sprayed negative electrode sheet through a box with a relative humidity of 85%~95% for about 3 minutes;

[0044] (3) After taking the negative electrode out of the box, immediately bake it at 130~140°C. After baking, the moisture in the coating should be less than 200ppm.

[0045] 2. Prepare the soft-packed lithium-ion battery according to the existing conventional technology with the negative electrode sheet covered with the separator and the positive electrode sheet.

[0046] The above-mentioned lithium-ion battery is tested as follows:

[0047] 1. High tempe...

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PUM

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Abstract

The invention discloses a method for preparing a lithium ion battery diaphragm. The diaphragm is an insulated coating arranged on the surface of an anode plate or a cathode plate. The method comprises the following steps of: (1) dissolving 3 to 7 weight parts of polyvinylidene fluoride into 40 to 60 weight parts of organic solvent, adding 1 to 3 weight parts of inorganic powder, and mixing uniformly to obtain slurry; (2) spraying the slurry to the surface of the anode plate or the cathode plate, and placing the anode plate or the cathode plate in a box with the relative humidity of 85 to 98 percent for 2 to 5 minutes; and (3) taking the anode plate or the cathode plate out of the box, and baking the anode plate or the cathode plate at the temperature of between 80 and 150 DEG C till the anode plate or the cathode plate is dried. The method for preparing the diaphragm is simple, easy to implement and convenient for industrialized production; and because inorganic particles are doped in the diaphragm to form a skeleton, the extrusion resistance of the diaphragm is improved, shrinkage of the diaphragm at a high temperature can be prevented, and the safety of the lithium ion battery is improved.

Description

technical field [0001] The invention relates to a battery diaphragm, in particular to a preparation method of a lithium ion battery diaphragm. Background technique [0002] The internal structure of batteries (including lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and lithium batteries) mainly includes four parts: positive electrode, negative electrode, separator, and electrolyte. [0003] The separator is an insulating material, and its function is to prevent the short circuit between the cathode and the anode. At the same time, the diaphragm needs to have micropores, so that ions in the electrolyte can pass through the micropores freely. At present, the diaphragm is mostly made of rubber, plastic and other materials, and its material and structure determine that the diaphragm has inherent disadvantages such as poor thermal conductivity, easy shrinkage at high temperature, and resistance to extrusion. [0004] Taking lithium-ion batte...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/16H01M10/0525
CPCY02E60/122Y02E60/10
Inventor 李建国王风河
Owner BAODING SHANHE RIYUE INDAL
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