Inorganic/organic composite membrane, preparation method of inorganic/organic composite membrane and lithium ion secondary battery containing membrane

An inorganic composite and separator technology, applied in secondary batteries, battery pack components, circuits, etc., can solve the problems of small compactness, small surface roughness, insufficient bulk density of the separator, poor heat resistance of the separator, etc., to improve safety and stability. , The effect of preventing fire accidents and reducing the resistance of transmission

Active Publication Date: 2014-09-24
东莞市魔方新能源科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The first aspect of the task of the present invention is at least one surface of the porous substrate by coating at least two kinds of porous insulating layers composed of inorganic particles and binders with different average particle sizes in a gradient change, to provide a kin

Method used

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  • Inorganic/organic composite membrane, preparation method of inorganic/organic composite membrane and lithium ion secondary battery containing membrane
  • Inorganic/organic composite membrane, preparation method of inorganic/organic composite membrane and lithium ion secondary battery containing membrane
  • Inorganic/organic composite membrane, preparation method of inorganic/organic composite membrane and lithium ion secondary battery containing membrane

Examples

Experimental program
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Effect test

Embodiment 1

[0051] The preparation methods of the positive electrode sheet, the negative electrode sheet and the lithium ion secondary battery are the same as those of Comparative Example 1.

[0052] Such as figure 1 As shown, the porous substrate g1 of the organic / inorganic composite diaphragm is coated with a layer of porous insulation g2, and the inorganic particles in the porous insulation layer g2 include two different particle sizes of the first type of inorganic particles g21 and the second type of inorganic particles g22 , The binder adheres to the surface of the inorganic particles after mixing with the inorganic particles, which is not shown in the figure.

[0053] Preparation of diaphragm:

[0054] (1) Preparation of porous insulating layer g2

[0055] Add 15wt% polyacrylate emulsion (40% in the aqueous solution) to deionized water, stir for 1h, and then add 40% of the first Al 2 O 3  Particles (average particle size of 0.3μm, particle size distribution of 0.05~2.0μm) and 45wt% of the ...

Embodiment 2

[0059] The preparation methods of the positive electrode sheet, the negative electrode sheet and the lithium ion secondary battery are the same as those of Comparative Example 1.

[0060] Preparation of diaphragm:

[0061] (1) Preparation of porous insulating layer g2

[0062] Add 15wt% polyacrylate emulsion (40% in aqueous solution) to deionized water, stir for 1h, and then add 25% of the first Al 2 O 3 Inorganic particles (the average particle size is 0.3μm, and the particle size distribution range is 0.08~2μm), 30% of the second type Al 2 O 3 Inorganic particles (average particle size of 0.6μm, particle size distribution range of 0.1~3.0μm) and 30wt% of the third type Al 2 O 3 The particles (average particle size of 1.0μm, particle size distribution range of 0.1~4.5μm) were stirred for 2h and then ground in a ball mill for 1h to prepare a slurry with a solid content of 40%.

[0063] (2) Coating a porous insulating layer g2 on the surface of the porous substrate g1

[0064] Take a pol...

Embodiment 3

[0066] (1) Preparation of porous insulating layer g2

[0067] Add 3wt% of polyvinylidene fluoride to N-methylpyrrolidone and stir at 45℃ for 1h, then add 40% of the first TiO 2 Particles (the average particle size is 0.25μm, the particle size distribution range is 0.08~1.8μm), 30% of the second type TiO 2 Particles (average particle size of 0.7μm, particle size distribution range of 0.1~3.5μm) and 27wt% third type TiO 2 The particles (the average particle size is 1.2μm, the particle size distribution range is 0.1~5μm) are stirred for 2h and then ground in a ball mill for 1h to prepare a slurry with a solid content of 65%.

[0068] (2) Coating a porous insulating layer g2 on the surface of the porous substrate g1

[0069] Take a polypropylene microporous film with a thickness of 12μm as the porous substrate g1, and then use gravure coating to uniformly cover the prepared slurry on one surface of the porous substrate g1 with a coating thickness of 2μm, and then divide the pole pieces in...

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Abstract

The invention discloses an inorganic/organic composite membrane which comprises a porous substrate and a porous insulating layer, wherein the porous insulating layer is attached to the porous substrate, and at least one surface of the porous substrate is coated with the porous insulating layer; the porous insulating layer comprises inorganic particles and a binding agent, wherein the inorganic particles are composed of n particles with different average particle diameters, n is large than or equal to 2, and the average particle diameters from the first type of inorganic particles to the nth type of inorganic particles are changed in a gradient manner. The invention further discloses a preparation method of the inorganic/organic composite membrane. The preparation method comprises the following steps: firstly, dissolving the binding agent into a solvent to form a polymer solution, then adding the inorganic particles, mixing to prepare the porous insulating layer, and then coating at least one surface of the porous substrate with the porous insulating layer. The invention further discloses a lithium ion secondary battery containing the membrane. The inorganic/organic composite membrane disclosed by the invention has the advantages of high stacking density, low thermal shrinkage rate, high puncture strength, simple preparation process and proper cost, and the lithium ion secondary battery containing the membrane has the advantages of good conservation rate of circulating volume and excellent safety performance and electrochemical performance.

Description

technical field [0001] The invention relates to the technical field of lithium-ion secondary batteries, in particular to an inorganic / organic composite membrane, a preparation method thereof and a lithium-ion secondary battery containing the membrane. Background technique [0002] Due to the characteristics of high energy density, high working voltage and light weight, lithium-ion secondary batteries have been widely used in consumer electronics products, such as mobile phones, notebook computers, tablet computers, Bluetooth headsets, MP3 and digital cameras. With the increasingly severe environmental pollution and energy crisis, the use of lithium-ion secondary batteries in power batteries and stationary power stations has become more and more popular, but the safety of lithium-ion secondary batteries has always been the focus of attention. [0003] The diaphragm of the lithium-ion secondary battery is used as the isolation of the positive and negative electrodes. It must...

Claims

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Application Information

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IPC IPC(8): H01M2/16H01M10/0525H01M50/446
CPCY02E60/122H01M10/0525H01M50/403H01M50/446Y02E60/10
Inventor 蒋中林
Owner 东莞市魔方新能源科技有限公司
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