Lithium ionic secondary cell barrier, preparation and lithium ionic cell thereof

A secondary battery, lithium ion technology, applied in secondary batteries, battery pack components, circuits, etc., can solve problems such as short circuit at the edge of the positive current collector, achieve simple and easy operation in the production process, reduce safety accidents, and resist edge burrs Strong piercing effect

Inactive Publication Date: 2011-04-06
BYD CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a separator for lithium ion batteries and a method for manufacturing the separator, which solves the problem in the prior art that the burrs on the edge of the positive current collector are easy to pierce the separator and cause an internal short circuit. Under the environment of use, the thermal shrinkage of the edge of the separator can be suppressed, and the short circuit of the battery caused by the direct contact of the positive and negative electrodes caused by the thermal shrinkage of the edge of the separator can be prevented.

Method used

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  • Lithium ionic secondary cell barrier, preparation and lithium ionic cell thereof
  • Lithium ionic secondary cell barrier, preparation and lithium ionic cell thereof
  • Lithium ionic secondary cell barrier, preparation and lithium ionic cell thereof

Examples

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Effect test

Embodiment 1

[0027] This example is used to illustrate the preparation method of the positive electrode of the battery provided by the present invention, the preparation of the diaphragm, and the lithium ion battery prepared by using the diaphragm.

[0028] (1) Preparation of positive electrode

[0029] Dissolve 30 grams of polyvinylidene fluoride (PVDF) in 450 grams of N-methylpyrrolidone (NMP) solvent to prepare a binder solution, and then mix 940 grams of LiCoO 2 Add 30 grams of acetylene black powder to the above solution, stir and mix evenly to obtain a positive electrode slurry; use a pulper to evenly coat the positive electrode slurry on both sides of an aluminum foil with a thickness of 18 microns to form a thickness of ? mm coating layer, and then put the pole piece in an oven and bake at 100° C. for 5 hours for sheeting treatment to obtain a positive pole piece with a thickness of 0.135 mm. Cut the sheet again to make a positive electrode of 550 mm (length) × 44 mm (width), each...

Embodiment 2

[0038] The heat-resistant resin is polyamide resin (PA6), 450 grams of N-methylpyrrolidone (NMP) solvent, and 85 grams of thermoplastic resin polymethyl methacrylate are stirred and dispersed evenly to obtain a liquid composition. This liquid composition is coated on (the model is celgard30008) polypropylene / polyethylene / polypropylene three-layer composite membrane such as image 3 On the edge of the long side shown, the width of the coating is 0.6 cm.

[0039] The rest of the steps were the same as in Example 1 to prepare lithium ion battery A2.

[0040] 100 identical batteries A2 were prepared by the method of Example 2.

Embodiment 3

[0042]The heat-resistant resin is polyphenylene sulfide resin (R-4), 450 grams of N-methylpyrrolidone (NMP) solvent, and 80 grams of thermoplastic resin polyethylene powder are stirred and dispersed evenly to obtain a liquid composition. This liquid composition is coated on (the model is celgard30008) polypropylene / polyethylene / polypropylene three-layer composite membrane such as image 3 On the edge of the long side shown, coat a width of 1.5 cm.

[0043] The rest of the steps were the same as in Example 1 to prepare lithium ion battery A3.

[0044] 100 identical batteries A3 were prepared by the method of Example 3.

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Abstract

Disclosed is a lithium-ion secondary battery diaphragm (3), comprising two long sides (5) and two wide sides (6), at least two of which are coated with a width of 0.2cm to 2cm of heat-resistant resin (4) on the edges, wherein the heat-resistant temperature of the heat-resistant resin is 150 DEG C to 300 DEG C, and the shrinkage rate thereof is 0 to 1 percent; and a preparation method of the diaphragm and a lithium-ion battery containing the diaphragm. The diaphragm can solve the problems that the edge burrs of the positive current collector in the prior art easily puncture the diaphragm resulting in internal short circuit, and safety problems caused by the direct contact of the edges of the anode and the cathode due to the shrinkage of the diaphragm at higher ambient temperatures. The prepared diaphragm has advantages of strong ability of resisting against puncturing by the edge burrs, high temperature resistance and effectively reducing safety accidents caused by the direct contact of the edges of the anode and the cathode due to the shrinkage of the diaphragm at higher ambient temperatures.

Description

technical field [0001] The invention relates to a lithium-ion secondary battery diaphragm, a preparation method thereof and a lithium-ion battery. Background technique [0002] Lithium-ion secondary batteries are widely used as power sources for portable electronic products such as mobile phones and notebook computers due to their high energy density, light weight and no memory effect. How to improve the safety of lithium-ion batteries has always been the focus of research in battery design and development, especially battery safety issues caused by internal short circuits in batteries. [0003] A nonaqueous electrolyte battery is disclosed in CN1838472A, which has a positive pole, a negative pole and a separator, the positive pole is formed with a positive active material containing layer on the current collector, and the negative pole is formed with a negative active material containing layer on the current collector, The separator is interposed between the positive and n...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M2/14C09K21/14C08L101/12H01M10/0525H01M50/403H01M50/417H01M50/489
CPCY02E60/122Y02E60/10
Inventor 刘璋勇高秀玲姜占锋
Owner BYD CO LTD
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