Composite lithium ion battery diaphragm and preparation method thereof

An ion battery and composite lithium technology, which is applied in battery pack parts, circuits, electrical components, etc., can solve the problems of difficult to control the uniformity of coating thickness, potential safety hazards of lithium ion batteries, and large wear and tear of mechanical equipment, and achieve continuous stability. The effect of mass production, eliminating the defoaming process, and improving production efficiency

Active Publication Date: 2015-01-07
CANGZHOU MINGZHU SEPARATOR TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The main problems in the current coating technology are: 1. The bonding strength between the main coating material (ceramic particles and polymer binder) and the porous base film is low, and it is easy to peel off from the base film, increasing the battery resistance , thereby deteriorating battery performance; 2. The special requirements of lithium-ion batteries lead to narrow selection of dispersants. The dispersants in the coating slurry in the prior art are mostly organic salts, which have poor dispersion effects and affect the uniformity of the coating.
On the other hand, the addition of organic salts will bring new safety hazards to lithium-ion batteries; 3. The ceramic particles commonly used in coatings are alumina (Al 2 o 3 ) particles, the hardness of alumina is high, the wear and tear on mechanical equipment is great, and the uniformity of coating thickness is difficult to control, which is not conducive to continuous production

Method used

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  • Composite lithium ion battery diaphragm and preparation method thereof
  • Composite lithium ion battery diaphragm and preparation method thereof
  • Composite lithium ion battery diaphragm and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] Example 1: Weigh 0.8 kg of sodium carboxymethyl cellulose, 0.6 kg of nano-silica, 1 kg of styrene-acrylic latex, 10 kg of nano-alumina, 80 kg of nano-barium sulfate, and 270 kg of deionized water; Mix silicon oxide with 270 kg of deionized water and disperse for 10 minutes using ultrasonic waves to make 270.6 kg of inorganic nano-dispersion; mix 30 kg of inorganic nano-dispersion with 10 kg of nano-alumina and stir for 10 minutes to obtain mixture 1; take the remaining inorganic Mix the nano-dispersion liquid with 80 kg nano barium sulfate, stir for 20 minutes to obtain mixture two; mix mixture one and mixture two, continue to disperse for 1 hour, obtain mixture three; add 0.8 kg carboxymethylcellulose sodium, 1 kg benzene to mixture three After the acrylic latex is fully stirred evenly, the slurry is obtained by filtering with a 400-mesh stainless steel screen; a polyethylene-based film with a thickness of 16 μm is selected, and the porosity is 42%, and the slurry is co...

Embodiment 2

[0034] Example 2: Weigh 0.2 kg of hydroxyethyl cellulose, 0.2 kg of nano-titanium dioxide, 1.2 kg of polyvinyl alcohol, 8 kg of nano-alumina, 80 kg of nano-barium sulfate, and 60 kg of deionized water; mix 0.2 kg of nano-titanium dioxide with 60 kg of deionized water was mixed, and ultrasonic dispersion was used for 10 minutes to make 60.2 kg of inorganic nano-dispersion; 5.5 kg of inorganic nano-dispersion was mixed with 8 kg of nano-alumina, and stirred for 30 minutes to obtain mixture 1; the remaining amount of inorganic nano-dispersion Mix with 80 kg of nano-barium sulfate, stir for 30 minutes to obtain mixture 2; mix mixture 1 with mixture 2, continue to disperse for 3 hours, and obtain mixture 3; add 0.2 kg hydroxyethyl cellulose and 1.2 kg polyvinyl alcohol to mixture 3 and stir thoroughly After uniformity, the slurry was obtained by filtering with a 400-mesh stainless steel screen; a polypropylene base film with a thickness of 22 μm was selected, and the porosity was 42...

Embodiment 3

[0035] Example 3: Weigh 2 kg of methyl hydroxyethyl cellulose, 0.5 kg of nano-silica, 1.5 kg of nano-titanium dioxide, 3 kg of styrene-acrylic latex, 20 kg of nano-alumina, 75 kg of nano-barium sulfate, and 102 kg of deionized water ; Mix 0.5 kg nano-silicon dioxide, 1.5 kg nano-titanium dioxide with 102 kg of deionized water, and disperse for 40 minutes using ultrasonic waves to make 104 kg of inorganic nano-dispersion; take 21.5 kg of inorganic nano-dispersion and mix with 20 kg of nano-alumina , stirred for 50 minutes to obtain mixture one; take the remaining amount of inorganic nano-dispersion liquid and mix it with 75 kg nano-barium sulfate, and stir for 50 minutes to obtain mixture two; mix mixture one and mixture two, and continue to disperse for 8 hours to obtain mixture three; add After 2 kg of methyl hydroxyethyl cellulose and 3 kg of styrene-acrylic latex were fully stirred evenly, the slurry was obtained by filtering with a 400-mesh stainless steel screen; a polyeth...

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Abstract

The invention relates to a composite lithium ion battery diaphragm and a preparation method thereof. The composite lithium ion battery diaphragm comprises a base film and a coating (s) coated on the single side or the two sides of the base film; the coating is obtained by coating and drying slurry, the slurry contains 20-60 percent of a base material by weight percentage, and the balance is deionized water; the base material comprises the following substances in parts by weight: 0.2-4 parts of thickening agent, 0.2-3 parts of inorganic nanometer dispersing agent, 1-5 parts of polymer adhesive and 88-98 parts of nano alumina and nano barium sulfate, wherein the mass ratio of the nano alumina to the nano barium sulfate is 1: (1-10). The composite lithium ion battery diaphragm provided by the invention has the benefits that the coating uniformity is good, the bonding strength is high and the process is good; the abrasion of mechanical equipment can be reduced on the basis of ensuring uniform pore distribution, excellent air permeability and good foreign body puncture resistance, and continuous and stable mass production is facilitated.

Description

technical field [0001] The invention relates to a lithium-ion battery technology, in particular to a composite lithium-ion battery diaphragm and a preparation method thereof, belonging to the technical field of batteries. Background technique [0002] Lithium-ion batteries are widely used as power sources for various mobile devices due to their high energy density, high operating voltage, no memory effect, and long cycle life. Lithium-ion batteries usually include a positive electrode, a negative electrode, a separator and an electrolyte. As a barrier between the positive and negative electrodes, the separator plays a vital role in the performance of the lithium-ion battery. Therefore, the safety of the lithium-ion battery can be improved by improving the performance of the separator The research on safety, usability and craftsmanship has received more and more attention. The separators used in lithium-ion batteries are generally polyolefin porous membranes, whose melting p...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/14H01M2/16
CPCH01M50/403H01M50/44Y02E60/10
Inventor 武跃孙卫佳于中彬赵中雷王庆通庄浩然
Owner CANGZHOU MINGZHU SEPARATOR TECH CO LTD
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