Preparation method of lithium ion battery diaphragm

A technology for lithium ion batteries and separators, which is applied in the field of preparation of lithium ion battery separators, can solve the problems of difficulty in dispersion, easy agglomeration, and difficulty in uniformly dispersing the separator matrix, and achieves good rate performance and cycle performance, and the effect of improving puncture strength.

Inactive Publication Date: 2015-09-30
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, nanomaterials have a large specific surface area, and are difficult to disperse and easily agglomerate. It is difficult to disperse evenly in the separator matrix, which often leads to unsatisfactory performance of the obtained products.

Method used

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

Examples

Experimental program
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Effect test

Embodiment 1

[0019] (1) Weigh 0.01g of graphene nanosheets (volume negligible) and 100ml of dimethylacetamide respectively at room temperature and blend them, and then sonicate for 20min to prepare a graphene nanosheet dispersion with a concentration of 0.1g / L.

[0020] (2) Weigh a certain amount of high-density polyethylene and dissolve it in dibutyl phthalate at 180°C for 45 minutes, and prepare high-density polyethylene particles with a particle size of 100 nm by emulsion polymerization. The continuous phase in the emulsion polymerization method used For absolute ethanol.

[0021] (3) First weigh 15.0g of polyvinylidene fluoride into the Erlenmeyer flask, and at the same time add 3.0g of polyvinylpyrrolidone, 0.5g of high-density polyethylene particles, and then add 10ml of 0.1g / L graphene uniform dispersion, that is, 0.001 g graphene, followed by adding dimethylacetamide so that the mass percentages of polyvinylidene fluoride, polyvinylpyrrolidone, high-density polyethylene and dimeth...

Embodiment 2

[0031] (1) Weigh 0.01g of graphene nanosheets (negligible volume) and 100ml of dimethylacetamide at room temperature and blend them, and then ultrasonically prepare a dispersion of graphene nanosheets with a concentration of 0.1g / L for 20 minutes.

[0032] (2) Weigh a certain amount of high-density polyethylene and dissolve it in dibutyl phthalate at 180°C for 45 minutes, and prepare high-density polyethylene particles with a particle size of 100 nm by emulsion polymerization. The continuous phase in the emulsion polymerization method used For absolute ethanol.

[0033] (3) Weigh 12.0g of polyvinylidene fluoride-hexafluoropropylene into the conical flask, add 2.0g of polyvinylpyrrolidone, 0.5g of high-density polyethylene, and then add 0.1ml of 0.1g / L graphene uniform dispersion , that is, 0.00001g graphene, and then add dimethylacetamide, so that the mass percentages of polyvinylidene fluoride-hexafluoropropylene, polyvinylpyrrolidone, high-density polyethylene particles and...

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Abstract

The invention relates to a preparation method of a lithium ion battery diaphragm. The preparation method comprises the following steps: (1) preparing a graphene nanosheet dispersion liquid of which the concentration is lower than or equal to 0.1 g / L; (2) preparing polymer particles of which the particle diameters are smaller than or equal to 600 nm; (3) uniformly mixing the polymer particles, the graphene nanosheet dispersion liquid and a polymer to prepare a polymer, polymer particle and graphene co-mixed casting solution; (4) treating the casting solution according to an immersion precipitation method, so as to obtain a polymer, polymer particle and graphene lithium ion battery diaphragm. The diaphragm prepared according to the preparation method is suitable for different battery material systems, is 4.6V or higher in decomposition voltage, and has the advantages that the porosity rate and the ionic conductivity are respectively 30 percent and 50 percent or higher than those of a pure polymer diaphragm, the puncture strength is improved by 46 percent, and all the service performances are superior.

Description

technical field [0001] The invention relates to a preparation method of a lithium ion battery diaphragm. Background technique [0002] Lithium-ion batteries have become one of the most important chemical power sources in contemporary times due to their advantages such as high energy density, high output voltage, long cycle life, and environmental friendliness. At present, in addition to being widely used in mobile communications, digital products and other fields, lithium-ion batteries are gradually becoming an important power supply system in the fields of energy storage and electric vehicles. In lithium-ion batteries, the separator mainly plays the role of isolating positive and negative electrode materials and conducting lithium ions. The performance of the separator directly determines the cycle performance and safety performance of lithium-ion batteries. [0003] Lithium-ion batteries, especially power lithium-ion batteries, have stricter requirements on separator perf...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/16H01M10/0525H01M50/446
CPCH01M10/0525H01M50/403H01M50/409Y02E60/10
Inventor 刘久清何俊颖
Owner CENT SOUTH UNIV
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