Preparation method of lithium battery diaphragm

A lithium battery separator and coating liquid technology, applied in secondary batteries, battery pack parts, circuits, etc., can solve the problems of poor gas permeability of lithium battery separators, and achieve good flatness, low internal resistance, and good safety. Effect

Pending Publication Date: 2020-04-10
DONGGUAN DONGYANG SOLAR SCI RES & DEV CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Aiming at the problem in the prior art that the lithium battery diaphragm obtained when water is used as the solvent has poor gas permeability, the present invention provides a method for preparing a lithium battery diaphragm that is environmentally friendly and has good gas permeability

Method used

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  • Preparation method of lithium battery diaphragm
  • Preparation method of lithium battery diaphragm

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Experimental program
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Effect test

Embodiment 1

[0045] First, 20g of polyvinylidene fluoride resin, 6g of styrene-butadiene rubber emulsion, 0.5g of alkyl sulfate, 0.3g of octadecyltrimethylammonium chloride and 0.3g of sodium carboxymethylcellulose were added to 100g of deionized water, Stir evenly at 40°C; then filter through a sieve and stand for defoaming to obtain a PVDF coating solution.

[0046]Then connect the high-voltage power supply to a high-frequency relay, adjust the switching ratio of the high-frequency relay to 5:5, and the switching frequency to 200Hz; control the output voltage of the high-voltage power supply to 4kV, and form a pulsed voltage under the action of the high-frequency relay. Using a constant flow pump, the prepared PVDF coating solution is stably extruded through the needle at a speed of 10mL / min; and under the action of pulse voltage, the jet flow forms a uniform pattern on the surface of the PE base film with a moving speed of 200mm / s The dot matrix obtained PVDF composite diaphragm.

[00...

Embodiment 2

[0049] First, 20g of polyvinylidene fluoride resin, 5g of styrene-butadiene rubber emulsion, 0.5g of alkyl sulfate, 0.3g of octadecyltrimethylammonium chloride and 0.3g of sodium carboxymethylcellulose were added to 100g of deionized water, Stir evenly at 40°C; then filter through a sieve and stand for defoaming to obtain a PVDF coating solution.

[0050] Then connect the high-voltage power supply to a high-frequency relay, adjust the switching ratio of the high-frequency relay to 2:8, and the switching frequency to 150Hz; control the output voltage of the high-voltage power supply to 3.5kV, and form a pulsed voltage under the action of the high-frequency relay. Using a constant flow pump, the prepared PVDF coating liquid is stably extruded through the needle at a speed of 8mL / min; and under the action of pulse voltage, the jet flow forms a uniform pattern on the surface of the PE base film with a moving speed of 150mm / s The dot matrix obtained PVDF composite diaphragm.

[00...

Embodiment 3

[0053] First, 20g of polyvinylidene fluoride resin, 6g of styrene-butadiene rubber emulsion, 0.4g of alkyl sulfate, 0.3g of octadecyltrimethylammonium chloride and 0.3g of sodium carboxymethylcellulose were added to 100g of deionized water, Stir evenly at 40°C; then filter through a sieve and stand for defoaming to obtain a PVDF coating solution.

[0054] Then connect the high-voltage power supply to a high-frequency relay, adjust the switching ratio of the high-frequency relay to 4:6, and the switching frequency to 100Hz; control the output voltage of the high-voltage power supply to 3kV, and form a pulsed voltage under the action of the high-frequency relay. Using a constant flow pump, the prepared PVDF coating solution is stably extruded through the needle at a speed of 6mL / min; and under the action of pulse voltage, the jet flow forms a uniform pattern on the surface of the PE base film with a moving speed of 100mm / s The dot matrix obtained PVDF composite diaphragm.

[00...

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Abstract

The invention provides a preparation method of a lithium battery diaphragm. The preparation method comprises the following steps: jetting PVDF coating liquid onto a substrate by using a low-pressure pulse jet device through a constant-flow pump, and drying the substrate to obtain the lithium battery diaphragm. According to the invention, a low-pressure pulse jet process is adopted, the size and thickness of the formed single PVDF particle are uniform and consistent, the lattice arrangement of the PVDF particles is regular, the obtained diaphragm has the advantages of good smoothness, good airpermeability and low internal resistance, and the whole preparation process does not use an organic solvent and is environmentally friendly.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a preparation method of a lithium battery diaphragm. Background technique [0002] With the promotion of national policies, the new energy automobile industry has shown explosive development, thus driving the rapid development of the upstream raw material industry. It is estimated that in 2019, the demand for lithium battery separators will exceed 2.5 billion square meters. Moreover, in the next 5-10 years, the lithium battery separator will maintain a high growth rate of 30%. [0003] Lithium battery separator is the main component of lithium ion battery, its performance not only determines the interface structure and internal resistance of the battery, but also directly affects the capacity, rate, cycle and safety performance of the battery. Therefore, the development of high-performance lithium battery separators has become a research focus and hots...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/14H01M2/16H01M10/0525
CPCH01M10/0525H01M50/403H01M50/411H01M50/449Y02E60/10
Inventor 李义涛程宗盛邹智杰黄连红云晧张凌飞
Owner DONGGUAN DONGYANG SOLAR SCI RES & DEV CO LTD
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