Lithium ion battery and preparation method thereof

A lithium-ion battery and cell technology, which is used in the manufacture of electrolyte batteries, secondary batteries, battery pack components, etc., can solve the problems of easy leakage of liquid lithium-ion batteries and poor battery safety performance, and avoid external mechanical damage. , The effect of preventing battery leakage and corrosion

Active Publication Date: 2013-01-23
BYD CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The invention solves the technical problem in the prior art that the liquid lithium ion battery is easy to leak, resulting in poor safety performance of the battery

Method used

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  • Lithium ion battery and preparation method thereof
  • Lithium ion battery and preparation method thereof

Examples

Experimental program
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Effect test

Embodiment approach

[0021] As common knowledge of those skilled in the art, positive and negative tabs are drawn out from the battery cell for drawing out the internal current of the battery. The tabs can all be drawn out from one end face of the battery core, or can be drawn out from two end faces of the battery core respectively, which is not specifically limited in the present invention. As a preferred embodiment of the present invention, the tabs 4 are all drawn out from one end face of the cell; then the gel porous protective film 3 is wrapped around the cell 2 and the other end face where the tabs are not drawn out, such as figure 2 shown.

[0022] The present invention also provides the preparation method of described lithium ion battery, comprises the following steps:

[0023] A. Dissolving a polymer that can be swollen by an electrolyte in a solvent system to form a polymer solution, then coating the polymer solution on a porous substrate, and obtaining a polymer porous membrane after ...

Embodiment 1

[0034] (1) Preparation of polymer porous membrane: Dissolve 6 parts by weight of polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) in 94 parts by weight of acetone and stir evenly to obtain a polymer solution; the polyethylene porous substrate The polymer porous membrane A1 was obtained after being immersed in a polymer solution, taken out and dried.

[0035] (2) Preparation of battery cell: the positive electrode sheet containing lithium cobaltate and the negative electrode sheet containing artificial graphite are wound together with a polyethylene microporous separator with a thickness of 16 μm inserted thereinto, and a battery cell with a winding structure is assembled. One end of the cell leads out to a tab.

[0036] (3) Preparation of lithium-ion battery: use the polymer porous membrane A1 of step (1) to wrap the four sides of the battery cell and a bottom surface where the tabs are not drawn out, and then insert it into the battery case as a whole, inject electrolyte,...

Embodiment 2

[0038] The lithium-ion battery S2 of this example was prepared in the same manner as in Example 1, the difference being that:

[0039] In step (1), 6 parts by weight of polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) was dissolved in a solvent system containing 89 parts by weight of acetone and 5 parts by weight of water, and stirred evenly to obtain this example polymer solution; the polypropylene porous substrate is immersed in the polymer solution, taken out and dried to obtain the polymer porous membrane A2;

[0040] In step (2), the polyethylene microporous membrane with a thickness of 20 μm was used instead of the polyethylene microporous membrane with a thickness of 16 μm in Example 1.

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Abstract

The invention provides a lithium ion battery which comprises a housing, and a battery core and electrolyte accommodated within the housing, A gel porous protection film is arranged between the housing and the battery core, and coats the outside of the battery core so as to absorb the electrolyte flowing out from the battery core and swell, and the film comprises a porous substrate and gel polymer located on the porous substrate. The invention further provides a preparation method of the lithium ion battery. The lithium ion battery provided by the invention can effectively prevent leakage inside the battery and has a good safety performance.

Description

technical field [0001] The invention belongs to the field of secondary batteries, in particular to a lithium ion battery and a preparation method thereof. Background technique [0002] Liquid lithium-ion batteries have the advantages of long cycle life, high open circuit voltage, high energy density, and no memory effect. Since their introduction in the 1990s, they have been widely used in electronic devices such as mobile phones, notebook computers, MP3, MP4, and cameras. . However, the disadvantage of liquid lithium-ion batteries is that they use highly fluid organic solutions, so leakage, corrosion, and combustion are prone to occur during use, and there are certain safety hazards. [0003] In view of the existing problems of liquid lithium-ion batteries, polymer lithium-ion batteries using gel state or solid electrolytes have attracted extensive attention from academia and industry. However, because the ionic conductivity of the colloidal electrolyte is lower than that...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M10/0525H01M2/02H01M10/058
CPCY02E60/122Y02E60/10Y02P70/50
Inventor 玉正日钟滢龚娅刘善文梁世硕
Owner BYD CO LTD
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