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Lithium ion battery diaphragm material and preparation method thereof

A lithium-ion battery and diaphragm material technology, which is applied in the field of lithium-ion battery diaphragm materials and its preparation, can solve the problems of unstable diaphragm size, easy shrinkage, high temperature of the battery, etc., and achieve improved resistance to electrolyte dissolution, good safety and , the effect of good battery capacity

Inactive Publication Date: 2016-02-24
浙江锂盾储能材料技术有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantages of the existing polyolefin separators are: 1. The polyolefin separator is easy to shrink when heated, which will cause the size of the separator to be unstable, and the positive and negative electrodes will directly contact and cause a short circuit; 2. The closed cell temperature and membrane rupture temperature are low. When wearing and other conditions, a large amount of heat is released inside the battery, causing the diaphragm to completely melt and shrink, and the battery is short-circuited to generate high temperature until the battery disintegrates or explodes

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] A lithium-ion battery diaphragm material includes a base film material and a coating, the base film material includes polyethylene and porous aluminum oxide ultrafine powder; the coating is polytetrafluoroethylene.

[0020] Among them, the particle size of the porous alumina ultrafine powder is 3000 mesh, the pore size is 5nm, and the pore density is 10 10 piece / cm 2 . The content of the alumina superfine powder accounts for 0.1% of the base film material.

[0021] A preparation method for preparing a lithium-ion battery diaphragm material, comprising the following steps:

[0022] Step 1, polyethylene and porous alumina ultrafine powder are uniformly mixed to obtain a polyolefin mixture;

[0023] Step 2, the polyolefin mixture is extruded, cooled, and cut in a twin-screw extruder, the melt coextrusion temperature of the extruder is 130°C, and the cooling temperature is 5°C;

[0024] Step 3, take the material in step 2 and extrude it twice in a twin-screw extruder, c...

Embodiment 2

[0028] A lithium-ion battery diaphragm material, comprising a base film material and a coating, the base film material comprising polypropylene and porous aluminum oxide ultrafine powder; the coating is made of polyvinylidene fluoride and polychlorotrifluoroethylene mixture.

[0029] Among them, the particle size of the porous alumina ultrafine powder is 4000 mesh, the pore size is 50nm, and the pore density is 10 11 piece / cm 2 . The content of the alumina ultrafine powder accounts for 2% of the base film material.

[0030] A preparation method for preparing a lithium-ion battery diaphragm material, comprising the following steps:

[0031] Step 1, polypropylene and porous alumina ultrafine powder are uniformly mixed to obtain a polyolefin mixture;

[0032] Step 2, the polyolefin mixture is extruded, cooled, and cut in a twin-screw extruder, the melt co-extrusion temperature of the extruder is 150°C, and the cooling temperature is 20°C;

[0033] Step 3, take the material i...

Embodiment 3

[0037] A lithium-ion battery diaphragm material, comprising a base film material and a coating, the base film material comprising a mixture of polyethylene and polypropylene and porous aluminum oxide ultrafine powder; the coating is tetrafluoroethylene and polytrifluoroethylene Mixtures of vinyl chloride.

[0038] Among them, the particle size of the porous alumina ultrafine powder is 5000 mesh, the pore size is 100nm, and the pore density is 10 12 piece / cm 2 . The content of the alumina superfine powder accounts for 3% of the base film material.

[0039] A preparation method for preparing a lithium-ion battery diaphragm material, comprising the following steps:

[0040] Step 1, uniformly mixing a mixture of polyethylene and polypropylene and porous alumina ultrafine powder to obtain a polyolefin mixture;

[0041] Step 2, the polyolefin mixture is extruded, cooled, and cut in a twin-screw extruder, the melt coextrusion temperature of the extruder is 180°C, and the cooling ...

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Abstract

The invention provides a lithium ion battery diaphragm material and a preparation method thereof. The diaphragm material comprises base diaphragm materials and a coating layer, wherein the base diaphragm materials comprise polyolefin and porous aluminium oxide ultrafine powder; the coating layer is a fluoride varnish. The preparation method of the lithium ion battery diaphragm material comprises the steps of 1, evenly mixing the aluminium oxide ultrafine powder and the polyolefin; 2, extruding a polyolefin mixture in a twin-screw extruder. For a base diaphragm of the diaphragm material, the polyolefin and the porous aluminium oxide ultrafine powder are selected as the base diaphragm materials, so that the pore closing temperature of the diaphragm can be effectively reduced, and the pore uniformity of the diaphragm can be effectively improved; the surface of the diaphragm material is coated with a carbon-containing fluorine diaphragm material, so that the electrolyte dissolution resistance of a fluorine diaphragm can be effectively improved, and better safety and battery capacity are achieved in a battery application process.

Description

technical field [0001] The invention relates to the field of lithium battery materials, in particular to a lithium ion battery diaphragm material and a preparation method thereof. Background technique [0002] Lithium-ion batteries are important green energy batteries. Due to their light weight, large specific capacity and safety, they have been widely used in mobile power supplies, notebook computers, mobile phones, and power vehicles. Lithium-ion batteries are generally composed of battery casing (packaging material), positive electrode, negative electrode, diaphragm and electrolyte. The diaphragm is an important material for isolating the positive and negative electrodes of the inner core of the battery. During the use of the battery, lithium ions can freely pass through the diaphragm to realize the battery life. The quality of charging and discharging is directly related to the service life and safety performance of the battery. [0003] At present, lithium-ion battery ...

Claims

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Application Information

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IPC IPC(8): H01M2/14H01M2/16H01M10/0525H01M50/403H01M50/406H01M50/446H01M50/449H01M50/491
CPCH01M10/0525H01M50/40H01M50/446H01M50/403Y02E60/10
Inventor 章结兵谢凤秀
Owner 浙江锂盾储能材料技术有限公司