CN113224305A - Preparation method of modified polyvinylidene fluoride for lithium ion battery - Google Patents
Preparation method of modified polyvinylidene fluoride for lithium ion battery Download PDFInfo
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- CN113224305A CN113224305A CN202110505473.7A CN202110505473A CN113224305A CN 113224305 A CN113224305 A CN 113224305A CN 202110505473 A CN202110505473 A CN 202110505473A CN 113224305 A CN113224305 A CN 113224305A
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/621—Binders
- H01M4/622—Binders being polymers
- H01M4/623—Binders being polymers fluorinated polymers
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F122/00—Homopolymers of compounds having one or more unsaturated aliphatic radicals each having only one carbon-to-carbon double bond, and at least one being terminated by a carboxyl radical and containing at least one other carboxyl radical in the molecule; Salts, anhydrides, esters, amides, imides or nitriles thereof
- C08F122/02—Acids; Metal salts or ammonium salts thereof, e.g. maleic acid or itaconic acid
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F2/00—Processes of polymerisation
- C08F2/44—Polymerisation in the presence of compounding ingredients, e.g. plasticisers, dyestuffs, fillers
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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Abstract
The invention discloses a preparation method of modified polyvinylidene fluoride for a lithium ion battery, which comprises the steps of adding graphene oxide into N, N-dimethylformamide, carrying out ultrasonic dispersion, then adding itaconic acid and azodiisobutyronitrile, heating to 60-70 ℃ in a nitrogen atmosphere, carrying out magnetic stirring reaction for 6-10 h, cooling, filtering and drying; adding the modified graphene oxide obtained in the step S1 into N, N-dimethylacetamide, carrying out ultrasonic treatment for 5-8 h, adding tin dichloride, raising the temperature to 60-70 ℃, stirring for 2-3 h, adding polyvinylidene fluoride and polyvinylpyrrolidone, continuing to magnetically stir for 10-16 h at the temperature, cooling, carrying out vacuum drying, putting into a ball mill, and grinding for 2-3 h to obtain the binder.
Description
Technical Field
The invention belongs to the technical field of lithium ion batteries, and particularly relates to a preparation method of modified polyvinylidene fluoride used in a lithium ion battery.
Background
Lithium ion batteries have been widely used in various digital electronic products because of a series of outstanding advantages such as high energy density, light weight, stable working voltage, long cycle life, high safety performance, and small environmental pollution. The electrode of the lithium ion battery is formed by coating positive and negative electrode materials on the surface of a current collector with a binder. The materials used as binders must therefore have the following main characteristics: 1) bonding the active materials to each other and to the current collector; 2) electrochemical stability, non-reactivity and mutual solubility with electrolytes; 3) the coating film has enough bonding strength when the amount is small, and does not fall off from the current collector to generate cracks; 4) high purity, less impurities and no denaturation at high temperature. Currently, polyvinylidene fluoride is the most widely used binder for lithium ion batteries. However, polyvinylidene fluoride and electrode materials have weak van der waals force, so that electrode particles are easy to fall off, and the specific discharge capacity is attenuated.
Disclosure of Invention
In view of the above problems, an object of the present invention is to provide a method for preparing modified polyvinylidene fluoride for use in lithium ion batteries, the method comprising the steps of:
s1: adding graphene oxide into N, N-dimethylformamide, carrying out ultrasonic dispersion, then adding itaconic acid and azobisisobutyronitrile, heating to 60-70 ℃ in a nitrogen atmosphere, carrying out magnetic stirring reaction for 6-10 h, cooling, filtering and drying.
S2: adding the modified graphene oxide obtained in the step S1 into N, N-dimethylacetamide, carrying out ultrasonic treatment for 5-8 h, adding tin dichloride, raising the temperature to 60-70 ℃, stirring for 2-3 h, adding polyvinylidene fluoride and polyvinylpyrrolidone, continuing to magnetically stir for 10-16 h at the temperature, cooling, carrying out vacuum drying, putting into a ball mill, and grinding for 2-3 h to obtain the binder.
Further, the mass ratio of the graphene oxide, the itaconic acid and the azobisisobutyronitrile in the step S1 is (1-2): 0.46-0.66: (0.24-0.39).
Furthermore, the mass-volume ratio of the modified graphene oxide to the N, N-dimethylacetamide neutralized tin dichloride is (0.69-0.88) g, (30-60) mL and (0.22-0.35) g.
Preferably, the mass ratio of the polyvinylidene fluoride to the polyvinylpyrrolidone is (8-15): (1.2-1.8).
Preferably, the molecular weight of the polyvinylpyrrolidone is 40000-55000.
Compared with the prior art, the invention has the following beneficial effects:
1. according to the invention, firstly, itaconic acid and azobisisobutyronitrile are adopted to modify graphene oxide, and then modified polyvinylidene fluoride is adopted, so that the graphene oxide has good linearity, and meanwhile, the surface of the graphene oxide is happy and rich in functional groups, and the bonding effect of a bonding agent and an active material can be improved after the graphene oxide is compounded with an electrode active material of a lithium ion battery.
2. In the invention, the polyvinylidene fluoride is modified by using the tin dichloride, so that the infiltration effect of the polyvinylidene fluoride binder and the electrolyte can be improved, and the binding effect can be further effectively improved by adding the polyvinylpyrrolidone.
Drawings
FIG. 1 is a graph showing the peel strength test results of modified polyvinylidene fluoride binders prepared in examples 1 to 4 of the present invention.
Detailed Description
The following embodiments of the present invention are described in detail, and the embodiments are implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, it should be noted that, for those skilled in the art, a plurality of modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Example 1
A preparation method of modified polyvinylidene fluoride for lithium ion batteries specifically comprises the following steps:
s1: adding graphene oxide into N, N-dimethylformamide, carrying out ultrasonic dispersion, then adding itaconic acid and azobisisobutyronitrile, heating to 60 ℃ in a nitrogen atmosphere, carrying out magnetic stirring reaction for 6 hours, cooling, filtering and drying; wherein the mass ratio of the graphene oxide to the itaconic acid to the azobisisobutyronitrile is 1:0.46: 0.24.
S2: adding the modified graphene oxide obtained in the step S1 into N, N-dimethylacetamide, performing ultrasonic treatment for 5 hours, adding tin dichloride, raising the temperature to 60 ℃, stirring for 2 hours, adding polyvinylidene fluoride and polyvinylpyrrolidone, continuing to perform magnetic stirring for 10 hours at the temperature, cooling, performing vacuum drying, putting into a ball mill, and grinding for 2 hours to obtain the binder; the mass volume ratio of the modified graphene oxide to the N, N-dimethylacetamide neutralized tin dichloride is 0.69g to 30mL to 0.22g, and the mass ratio of the polyvinylidene fluoride to the polyvinylpyrrolidone is 8: 1.2.
Example 2
A preparation method of modified polyvinylidene fluoride for lithium ion batteries specifically comprises the following steps:
s1: adding graphene oxide into N, N-dimethylformamide, carrying out ultrasonic dispersion, then adding itaconic acid and azobisisobutyronitrile, heating to 70 ℃ in a nitrogen atmosphere, carrying out magnetic stirring reaction for 10 hours, cooling, filtering and drying; wherein the mass ratio of the graphene oxide to the itaconic acid to the azobisisobutyronitrile is 2:0.66: 0.39.
S2: adding the modified graphene oxide obtained in the step S1 into N, N-dimethylacetamide, performing ultrasonic treatment for 8 hours, adding tin dichloride, raising the temperature to 70 ℃, stirring for 3 hours, adding polyvinylidene fluoride and polyvinylpyrrolidone, continuing to perform magnetic stirring for 16 hours at the temperature, cooling, performing vacuum drying, putting into a ball mill, and grinding for 3 hours to obtain the binder; the mass volume ratio of the modified graphene oxide to the N, N-dimethylacetamide neutralized tin dichloride is 0.88g to 60mL to 0.35g, and the mass ratio of the polyvinylidene fluoride to the polyvinylpyrrolidone is 15: 1.8.
Example 3
A preparation method of modified polyvinylidene fluoride for lithium ion batteries specifically comprises the following steps:
s1: adding graphene oxide into N, N-dimethylformamide, carrying out ultrasonic dispersion, then adding itaconic acid and azobisisobutyronitrile, heating to 65 ℃ in a nitrogen atmosphere, carrying out magnetic stirring reaction for 8 hours, cooling, filtering and drying; wherein the mass ratio of the graphene oxide to the itaconic acid to the azobisisobutyronitrile is 1.3:0.54: 0.29.
S2: adding the modified graphene oxide obtained in the step S1 into N, N-dimethylacetamide, performing ultrasonic treatment for 7 hours, adding tin dichloride, raising the temperature to 65 ℃, stirring for 2.5 hours, adding polyvinylidene fluoride and polyvinylpyrrolidone, continuing to perform magnetic stirring for 12 hours at the temperature, cooling, performing vacuum drying, putting into a ball mill, and grinding for 2.5 hours to obtain the binder; the mass volume ratio of the modified graphene oxide to the N, N-dimethylacetamide neutralized tin dichloride is 0.75g to 40mL to 0.28g, and the mass ratio of the polyvinylidene fluoride to the polyvinylpyrrolidone is 12 to 1.5.
Example 4
A preparation method of modified polyvinylidene fluoride for lithium ion batteries specifically comprises the following steps:
s1: adding graphene oxide into N, N-dimethylformamide, carrying out ultrasonic dispersion, then adding itaconic acid and azobisisobutyronitrile, heating to 68 ℃ in a nitrogen atmosphere, carrying out magnetic stirring reaction for 9 hours, cooling, filtering and drying; wherein the mass ratio of the graphene oxide to the itaconic acid to the azobisisobutyronitrile is 1.7:0.62: 0.36.
S2: adding the modified graphene oxide obtained in the step S1 into N, N-dimethylacetamide, performing ultrasonic treatment for 7 hours, adding tin dichloride, raising the temperature to 68 ℃, stirring for 3 hours, adding polyvinylidene fluoride and polyvinylpyrrolidone, continuing to perform magnetic stirring for 14 hours at the temperature, cooling, performing vacuum drying, putting into a ball mill, and grinding for 3 hours to obtain the binder; the mass volume ratio of the modified graphene oxide to the N, N-dimethylacetamide neutralized tin dichloride is 0.85g to 50mL to 0.34g, and the mass ratio of the polyvinylidene fluoride to the polyvinylpyrrolidone is 13: 1.6.
And (3) performance testing: preparing uniform anode slurry, namely mixing an anode active material lithium iron phosphate, a conductive agent and a binder polyvinylidene fluoride according to a mass ratio of 8:1:1, and performing ball milling for 2 hours to obtain the uniform anode slurry. Preparation of test sample strips: the positive electrode slurry is coated on an aluminum foil, dried and subjected to sample preparation according to the sample preparation requirement in the standard GB/T2790-1995 adhesive 180-degree peel strength test method for flexible materials versus rigid materials, the result is shown in the attached figure 1, and the bonding strength of the modified polyvinylidene fluoride adhesive prepared in the examples 1-4 is 2.84KN m-1As described above, the adhesive of the present invention has excellent adhesive strength.
Claims (5)
1. A preparation method of modified polyvinylidene fluoride for lithium ion batteries is characterized by comprising the following steps:
s1: adding graphene oxide into N, N-dimethylformamide, performing ultrasonic dispersion, then adding itaconic acid and azodiisobutyronitrile, heating to 60-70 ℃ in a nitrogen atmosphere, performing magnetic stirring reaction for 6-10 h, cooling, filtering and drying;
s2: adding the modified graphene oxide obtained in the step S1 into N, N-dimethylacetamide, carrying out ultrasonic treatment for 5-8 h, adding tin dichloride, raising the temperature to 60-70 ℃, stirring for 2-3 h, adding polyvinylidene fluoride and polyvinylpyrrolidone, continuing to magnetically stir for 10-16 h at the temperature, cooling, carrying out vacuum drying, putting into a ball mill, and grinding for 2-3 h to obtain the binder.
2. The method as claimed in claim 1, wherein the mass ratio of graphene oxide to itaconic acid to azobisisobutyronitrile in the step S1 is (1-2): 0.46-0.66): 0.24-0.39.
3. The preparation method of the modified polyvinylidene fluoride used in the lithium ion battery according to claim 1, wherein the mass-to-volume ratio of the modified graphene oxide to the N, N-dimethylacetamide and the tin dichloride is (0.69-0.88) g, (30-60) mL and (0.22-0.35) g.
4. The method for preparing the modified polyvinylidene fluoride used in the lithium ion battery as claimed in claim 1, wherein the mass ratio of the polyvinylidene fluoride to the polyvinylpyrrolidone is (8-15): (1.2-1.8).
5. The preparation method of the modified polyvinylidene fluoride used in the lithium ion battery according to claim 1, wherein the molecular weight of the polyvinylpyrrolidone is 40000-55000.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114085302A (en) * | 2021-11-16 | 2022-02-25 | 江苏超电新能源科技发展有限公司 | Preparation method and application of chlorinated polyvinylidene fluoride material |
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Patent Citations (6)
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| US20130316234A1 (en) * | 2011-01-06 | 2013-11-28 | Mitsubishi Rayon Co., Ltd. | Modifier for polyvinylidene fluoride, binder resin composition for battery, electrode for secondary battery and battery |
| US20130337320A1 (en) * | 2012-06-15 | 2013-12-19 | Semiconductor Energy Laboratory Co., Ltd. | Method for manufacturing storage battery electrode, storage battery electrode, storage battery, and electronic device |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114085302A (en) * | 2021-11-16 | 2022-02-25 | 江苏超电新能源科技发展有限公司 | Preparation method and application of chlorinated polyvinylidene fluoride material |
| CN114085302B (en) * | 2021-11-16 | 2023-03-14 | 江苏超电新能源科技发展有限公司 | Preparation method and application of chlorinated polyvinylidene fluoride material |
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