Diaphragm for lithium ion battery, production method thereof, and battery core

A technology for a lithium ion battery and a production method, applied in the field of lithium ion batteries, can solve the problems of easy piercing of the separator, easy generation of dendrites, etc., and achieve the effects of reducing volume expansion, increasing absorption, and reducing internal resistance

Active Publication Date: 2015-04-01
天津蓝天特种电源科技股份公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For Li / CFx, the negative electrode Li band inside the cell is prone to dendrites, which can easily pierce the separator

Method used

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  • Diaphragm for lithium ion battery, production method thereof, and battery core
  • Diaphragm for lithium ion battery, production method thereof, and battery core
  • Diaphragm for lithium ion battery, production method thereof, and battery core

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0049] (1) Pretreatment of diaphragm:

[0050] At 80°C, the volume ratio of the prepared chromic acid oxidation solution is: K 2 Cr 2 o 7 :H 2 SO 4 :H 2 O=1:20:2, soak the polyethylene (PE) base film in the chromic acid oxidizing solution for 30 minutes, and corrode the base film by the acid oxidizing solution to corrode the surface of the base film so that the base film becomes a porous structure . Then rinse off the oxidizing solution with deionized water several times, and dry it for later use.

[0051] (2) Coating of aluminum nitride: Coating an aluminum nitride (AlN) nano film on the surface of the pretreated base film corresponding to the negative electrode, wherein the thickness of the AlN film is at the micron level, the specific method As follows: Put the aluminum nitride (AlN) ceramic powder into the vacuum radio frequency sputtering equipment, the side not coated with PTFE is used as the substrate, adjust the voltage and current of the equipment and the radio...

Embodiment 2

[0053] (1) Pretreatment of diaphragm:

[0054] At 80°C, the volume ratio of the prepared chromic acid oxidation solution is: K 2 Cr 2 o 7 :H 2 SO 4 :H 2 O=1:20:2, soak the 20μm-thick composite diaphragm produced by Celgard (the composition is PP / PE / PP) in the above chromic acid oxidation solution for 30min, and corrode the base film by the acidic oxidation solution to make the base film The surface part is corroded, so that the base membrane becomes porous. Then rinse off the oxidizing solution with deionized water several times, and dry it for later use.

[0055] (2) Coating of PTFE: Add PTFE to absolute ethanol, stir and dissolve at 70°C to obtain a gel solution with a mass fraction of 20%, and apply this solution on the pretreated basement membrane by sol-gel method On the surface corresponding to the positive electrode, the thickness is controlled at about 5 μm. After an hour of absolute ethanol volatilization in the air, it is then immersed in a certain amount of a...

Embodiment 3

[0058] (1) Pretreatment of diaphragm:

[0059] At 80°C, the volume ratio of the prepared chromic acid oxidation solution is: K 2 Cr 2 o 7 :H 2 SO 4 :H 2 O=1:20:2, soak the polyethylene (PE) base film in the above oxidizing solution for 30 minutes, corrode the base film surface part by the acidic oxidizing solution, so that the base film becomes a porous structure, and then Rinse off the oxidizing solution several times with deionized water, and dry it for later use.

[0060] (2) Coating of PVDF: Add PVDF to absolute ethanol, stir and dissolve at 70°C to obtain a gel solution with a mass fraction of 20%, and apply the solution to the pretreated basement membrane by sol-gel method On the surface corresponding to the positive electrode, the thickness is controlled at about 5 μm. After an hour of absolute ethanol volatilization in the air, it is then immersed in a certain amount of absolute ethanol to control the phase inversion of the coating solution. In a drying room at r...

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Abstract

The invention discloses a diaphragm for lithium ion battery, a production method thereof, and a battery core, and provides a diaphragm capable of improving battery safety, a production method thereof, and a battery core. The diaphragm for lithium ion battery comprises a base film, the surface of one side opposite to the battery cathode of the base film is provided with an aluminum nitride nano thin-film, and the surface of the other side opposite to the battery anode of the base film is provided with a polytetrafluoroethylene thin-film or a polyvinylidene fluoride thin-film. The surface of one side opposite to the battery cathode of the base film of the diaphragm is provided with a compact aluminum nitride thin-film, because of good toughness of the aluminum nitride, the fusing temperature is improved while maintaining the original obturator temperature of the diaphragm, and thus the contraction rate of the diaphragm is maximally inhibited. The contraction rate of the diaphragm, which has been coated with an aluminum nitride layer, can reduced to around 1% during hotbox or short-circuit. The diaphragm is especially suitable for safety tests of needling, short-circuit, and hotbox, and improves the safety of batteries.

Description

technical field [0001] The invention relates to the technical field of lithium-ion batteries, in particular to a separator for lithium-ion batteries, a production method thereof, and an electric core. Background technique [0002] Lithium-ion batteries are widely used in mobile communication equipment, portable electronic equipment, electric tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace and other fields, mainly including cylindrical batteries, square lithium-ion batteries, Polymer lithium ion battery, etc. [0003] The battery diaphragm refers to a layer of diaphragm material between the positive and negative electrodes of the battery. Its main function 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. . The battery separator is a very critical part of the ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M2/16H01M10/0525H01M50/409
CPCY02E60/122Y02E60/10
Inventor 王俊明阳晓霞段征王希文
Owner 天津蓝天特种电源科技股份公司
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