Manufacturing method of lithium ion battery diaphragm as well as battery diaphragm prepared by manufacturing method and battery

A lithium ion battery and a manufacturing method technology are applied in the field of battery separators and batteries, which can solve the problems of poor quality, deterioration of battery performance, and high cost, and achieve the effects of reducing coating processes, avoiding poor quality, and increasing membrane breaking temperature.

Inactive Publication Date: 2015-02-18
DONGGUAN ADVANCED ELECTRONICS TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in order to ensure the standby time of electronic devices, the battery needs to be designed with sufficient capacity, which increases the length and width of the battery. Another disadvantage of this design is that the battery will be very soft and easily deformed, resulting in deterioration of battery performance.
In order to increase the hardness of the battery, the current solution is to dissolve the separator for the battery in an organic solvent with PVDF-HFP (vinylidene fluoride-hexafluoropropylene copolymer), and then coat it on the separator by dip coating, and then During the process, the thermal composite method is used to stick to the positive electrode sheet to increase the hardness of the battery. The disadvantage of using this method is that PVDF-HFP will enter the pores of the separator with the solvent, resulting in poor charge and discharge performance of the battery.
[0004] In order to solve the safety and hardness problems of the battery, there is another implementation method to first coat a layer of 2-6um ceramic layer on the separator, and then coat a layer of PVDF-HFP (vinylidene fluoride-hexafluoropropylene copolymer), This layer of PVDF-HFP corresponds to the positive pole piece, and then uses heating and compounding under the action of the electrolyte to bond the coating layer and the positive pole piece together to increase the hardness of the battery. Using this method, the separator needs to be coated with 2 Second, especially for the very thin diaphragm base material, it is difficult to coat itself, and multiple times of coating will cause poor quality and greatly increase the hidden dangers of quality, and the battery needs to be left standing at high temperature after adding electrolyte, the process is complicated, and the cost high

Method used

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  • Manufacturing method of lithium ion battery diaphragm as well as battery diaphragm prepared by manufacturing method and battery
  • Manufacturing method of lithium ion battery diaphragm as well as battery diaphragm prepared by manufacturing method and battery
  • Manufacturing method of lithium ion battery diaphragm as well as battery diaphragm prepared by manufacturing method and battery

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] A method for manufacturing a lithium ion battery separator, the process steps comprising:

[0031] a. Add 5% LBG-1 (a kind of polyvinylidene fluoride PVDF) into acetone, turn on the mixer and stir to dissolve into a uniform and transparent organic polymer material solution.

[0032] b. Add ceramic powder whose solid content accounts for 30% of the solution to the above solution, and the 50% cumulative diameter D50 in the particle size distribution of the ceramic powder is 0.5 microns, and stir evenly.

[0033] c. Evaporate and dry the solvent in the mixture by heating the above mixture, so that the surface of the ceramic particles 1 is coated with a layer of polyvinylidene fluoride resin PVDF 2 (see appendix). figure 1 ), the thickness of the coating layer 2 is about 0.1 micron, and the ceramic particle powder coated with the organic polymer material layer is obtained.

[0034] d. Add the coated ceramic powder into SBR (styrene butadiene rubber) emulsion, CMC (carboxym...

Embodiment 2

[0038] A method for manufacturing a lithium ion battery separator, the process steps comprising:

[0039] a. Add 10% LBG-1 (a kind of polyvinylidene fluoride PVDF) into acetone, turn on the mixer and stir to dissolve into a uniform and transparent solution.

[0040] b. Add ceramic powder whose solid content accounts for 30% of the solution to the above solution, and the 50% cumulative diameter D50 in the particle size distribution of the ceramic powder is 0.5um, and stir evenly.

[0041] c. Spray-dry the above mixture to remove the solvent in the mixture, so that the surface of the ceramic particles is coated with a layer of PVDF (see appendix). figure 1 ), the coating thickness is about 0.2 μm.

[0042] d. Add the coated ceramic powder into SBR (styrene butadiene rubber) emulsion, CMC (carboxymethyl cellulose) and deionized water and stir evenly.

[0043] e. Coat the above prepared slurry on a polypropylene membrane of a membrane substrate with a thickness of 9 microns by g...

Embodiment 3

[0046] A method for manufacturing a lithium ion battery separator, the process steps comprising:

[0047] a. Add ceramic powder and LBG-1 (a kind of polyvinylidene fluoride PVDF) into the mechanical fusion equipment at a ratio of 75:25 and mix evenly;

[0048] b. The mixture in step a is heated to 160 degrees, stirred for 2 hours and then cooled, so that LBG-1 forms a coating layer with a thickness of about 0.1 microns on the surface of the ceramic particles;

[0049] c. Add the coated ceramic powder into SBR (styrene-butadiene rubber) emulsion, and stir evenly with CMC (carboxymethyl cellulose) and deionized water.

[0050] d. Coat the above prepared slurry on a 9-micron polypropylene separator by gravure printing and dry, and the coating thickness is 3 microns after coating and drying.

[0051] Thereby, a lithium ion battery separator of the present embodiment can be obtained, the total thickness of the lithium ion battery separator is 12 microns, wherein the polypropylene ...

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Abstract

The invention discloses a manufacturing method of a lithium ion battery diaphragm as well as the battery diaphragm prepared by the manufacturing method and a battery. The manufacturing method comprises the following steps: a. covering the surface of ceramic power by one organic high molecular material layer through a solid-phase covering or liquid-phase covering manner to obtain ceramic grain powder covered with the organic high molecular material layer, and sieving the dried and granulated powder for later use; b. adding a solvent, glue and an impregnating compound into the ceramic powder coated in the last step to prepare ceramic slurry; and c. coating a lithium ion battery diaphragm base material by the ceramic slurry to prepare the lithium ion battery diaphragm. The ceramic is firstly covered with the high molecular material layer, and the enough rigidity of the lithium ion battery, and especially a thin, long and wide battery produced by the lithium ion battery diaphragm can be guaranteed; the shrinking percentage is low when the battery is heated, the diaphragm breaking temperature of the diaphragm is improved and the safety of the battery is improved; and the high molecular material layer only needs to be coated for one time, so that the cost is obviously reduced and the efficiency is improved by at least one time.

Description

technical field [0001] The invention relates to the technology in the field of lithium ion batteries, in particular to a method for manufacturing a lithium ion battery separator and the battery separator and battery prepared therefrom. Background technique [0002] Fossil resources represented by oil are decreasing day by day. Cars using oil as raw materials bring us convenience and also bring us a deteriorating environment. Human beings are sparing no effort to find clean alternative energy sources. Lithium-ion batteries have the advantages of small size, light weight and high energy density and can be used as clean energy in electric vehicles. The separator of lithium ion battery plays the role of separating the positive and negative electrodes in the battery. The commonly used lithium ion battery separator is polymer materials such as polyethylene, polypropylene or polyethylene and polypropylene composite materials. Pull-up or extraction methods are used to prepare porou...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/14H01M2/16H01M10/0525H01M50/403H01M50/434H01M50/443H01M50/449
CPCH01M10/0525H01M50/403H01M50/443Y02E60/10
Inventor 方祺陈卫刘勇标王晓明徐远新
Owner DONGGUAN ADVANCED ELECTRONICS TECH
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