Inorganic composite microporous membrane serving as lithium ion battery diaphragm and preparation method thereof

A lithium-ion battery and inorganic composite technology, applied in battery components, chemical instruments and methods, nanotechnology for materials and surface science, etc., can solve the problem of inability to effectively guarantee battery safety performance, battery diaphragm isolation battery Negative electrode, affecting the stability of battery performance and other issues, to achieve good high temperature resistance, prevent direct contact, and improve the effect of bonding strength

Inactive Publication Date: 2012-10-17
HENAN YITENG NEW ENERGY TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The production method has the disadvantages of complex process and low production efficiency; and, during the battery use, the battery is repeatedly charged and discharged, which will cause the inorganic material to easily fall off from the surface of the porous substrate. When the temperature of the battery rises, the battery diaphragm will not be able to It plays a very good role in isolating the positive and negative electrodes of the battery, but cannot effectively guarantee the safety performance of the battery and affects the stability of the battery performance

Method used

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  • Inorganic composite microporous membrane serving as lithium ion battery diaphragm and preparation method thereof
  • Inorganic composite microporous membrane serving as lithium ion battery diaphragm and preparation method thereof

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preparation example Construction

[0037] A preparation method for an inorganic composite microporous membrane used as a lithium-ion battery diaphragm, comprising the following steps:

[0038] Step 1. Co-extrude the inorganic composite polyolefin multilayer precursor through the multilayer die of the extrusion device, and cool the inorganic composite polyolefin multilayer precursor to obtain a sheet, wherein the sheet includes an intermediate layer and two outer layers, and the two outer layers are respectively located on both sides of the middle layer, wherein the middle layer is mainly composed of polyethylene, or a copolymer of ethylene and other olefins or a mixture of polyethylene and other polyolefins The two outer layers are mainly made of a mixture of polypropylene and nano-inorganic particles, and the nano-inorganic particles are at least one of aluminum oxide, magnesium oxide, calcium oxide and silicon oxide;

[0039] Step 2, biaxially stretching the sheet obtained in step 1 to obtain a film;

[0040...

Embodiment 1

[0043] The middle layer is made of polyethylene, which is a mixture of high-density polyethylene and low-density polyethylene, and the molecular weight of high-density polyethylene is 5×10 4 , the melting point is 130°C, and the molecular weight of low-density polyethylene is 3×10 3 , the melting point is 126°C, and the mass percentage of low-density polyethylene is 10%.

[0044] The outer layer solution includes polypropylene, nano inorganic particles and dispersant. Wherein, the nano-inorganic particles are aluminum oxide with a particle diameter of 500nm, the mass percentage of the nano-inorganic particles in the outer layer solution is 40%, and the mass percentage of polypropylene in the outer layer is 59%. The dispersant is polyethylene glycol, and the addition ratio is 1% of the total mass of the outer layer solution.

[0045] The middle layer solution and the outer layer solution are co-extruded through a three-layer die in the extrusion device, and the extruded precu...

Embodiment 2

[0048] The middle layer is made of polyethylene, which is a mixture of high-density polyethylene and low-density polyethylene, and the molecular weight of high-density polyethylene is 5×10 5 , the melting point is 135°C, and the molecular weight of low-density polyethylene is 1×10 4 , the melting point is 130°C, and the mass percentage of low-density polyethylene is 30%.

[0049] The outer layer solution includes polypropylene, nano inorganic particles and dispersant. Wherein, the nano-inorganic particles are magnesium oxide with a particle diameter of 40nm, the mass percentage of the nano-inorganic particles in the outer layer solution is 65%, and the mass percentage of polypropylene in the outer layer is 30%. The dispersant is polyvinyl alcohol, and the addition ratio is 5% of the total mass of the outer layer solution.

[0050] The middle layer solution and the outer layer solution are co-extruded through a three-layer die in the extrusion device, and the extruded precurs...

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Abstract

The invention relates to an inorganic composite microporous membrane serving as a lithium ion battery diaphragm and a preparation method of the inorganic composite microporous membrane. The inorganic composite microporous membrane is a co-extruded inorganic composite microporous membrane, and includes an intermediate layer and two outer layers, wherein the intermediate layer is mainly made of polyethylene, or the copolymer of ethylene and other olefins, or the mixture of polyethylene and other polyolefin; the two outer layers is mainly made of the mixture of polypropylene and inorganic nanoparticles; and the inorganic nanoparticles are selected from at least one of aluminum oxide, magnesium oxide, calcium oxide and silicon oxide. The inorganic composite microporous membrane provided by the invention has good unity, and can prevent shedding of the inorganic nanoparticles so as to ensure the stability of the battery performance during application of the inorganic composite microporous membrane. The preparation method provided by the invention can form the multilayer structure of the inorganic composite microporous membrane in one step by adopting co-extrusion method, thereby simplifying the production process, improving the production efficiency and improving the performance of the inorganic composite microporous membrane.

Description

technical field [0001] The invention relates to the field of battery separator production, in particular to an inorganic composite microporous membrane used as a lithium-ion battery separator and a preparation method thereof. Background technique [0002] The battery separator refers to a layer of separator material between the positive and negative electrodes of the battery. It is a very critical part of the battery and has a direct impact on battery safety and cost. The main function of the battery separator is to isolate the positive and negative electrodes and prevent the electrons in the battery from freely passing through, allowing the ions in the electrolyte to pass freely between the positive and negative electrodes. Therefore, the ion conductivity of the battery separator is directly related to the overall performance of the battery. The battery separator separates the positive and negative terminals of the battery. Because the battery separator has the self-closi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/16B32B27/06B32B27/30B82Y30/00B32B37/10
CPCY02E60/12Y02E60/10
Inventor 朱继中朱晓李顺阳靳磊朱磊曹俊梅邵发亮刘刚
Owner HENAN YITENG NEW ENERGY TECH
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