CN106784553B - Preparation method of polyolefin microporous membrane with ceramic coating, polyolefin microporous membrane and application - Google Patents
Preparation method of polyolefin microporous membrane with ceramic coating, polyolefin microporous membrane and application Download PDFInfo
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- CN106784553B CN106784553B CN201611228378.2A CN201611228378A CN106784553B CN 106784553 B CN106784553 B CN 106784553B CN 201611228378 A CN201611228378 A CN 201611228378A CN 106784553 B CN106784553 B CN 106784553B
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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
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
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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
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
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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
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/403—Manufacturing processes of separators, membranes or diaphragms
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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
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/411—Organic material
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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
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
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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 application discloses a preparation method of a polyolefin microporous membrane with a ceramic coating, the polyolefin microporous membrane and application. The preparation method of the polyolefin microporous membrane with the ceramic coating comprises the steps of carrying out fluorination treatment on a polyolefin microporous membrane base membrane, and then forming the ceramic coating on the surface of the polyolefin microporous membrane base membrane subjected to fluorination treatment; the fluorination treatment comprises subjecting the base film to fluorine gas at a concentration of 0.05% for 20 to 60 seconds. According to the preparation method of the polyolefin microporous membrane with the ceramic coating, the polyolefin microporous membrane is subjected to fluorination treatment in advance, then the ceramic coating is coated, the polarity and the wettability of the surface of the polyolefin microporous membrane can be effectively improved through the fluorination treatment, and the surface bonding force of the polyolefin microporous membrane and the ceramic coating is improved, so that the ceramic coating is uniformly coated and is not easy to fall off. And the fluorination treatment induces the molecular chain of the polyolefin microporous membrane to be entangled, so that the puncture resistance and the tensile strength are further improved.
Description
Technical Field
The application relates to the field of polyolefin microporous membranes, in particular to a preparation method of a ceramic coating polyolefin microporous membrane, a polyolefin microporous membrane prepared by the method and application.
Background
Currently, separators for lithium ion batteries are generally polyolefin microporous membranes, including polypropylene (abbreviated as PP) single-layer microporous membranes, polyethylene (abbreviated as PE) single-layer microporous membranes, and multilayer microporous membranes formed by compounding PP and PE. The polyolefin microporous membrane has the advantages of high porosity, high tear strength, high acid and alkali resistance, chemical reagent resistance, low price and the like; however, when the temperature of the battery is increased, particularly to 200 ℃, the polyolefin microporous membrane can shrink or melt, and further contact and short circuit between the positive electrode and the negative electrode are caused, so that unsafe accidents are caused. Therefore, it is desirable to apply ceramic coatings to improve their temperature resistance; however, the PP and PE microporous films are non-polar, and the ceramic coating is easily peeled off or unevenly coated, so that a short circuit phenomenon is easily caused during use.
Disclosure of Invention
The invention aims to provide an improved preparation method of a polyolefin microporous membrane with a ceramic coating, a polyolefin microporous membrane prepared by the method and application of the polyolefin microporous membrane.
In order to achieve the purpose, the following technical scheme is adopted in the application:
one aspect of the application discloses a preparation method of a polyolefin microporous membrane with a ceramic coating, which comprises the steps of carrying out fluorination treatment on a polyolefin microporous membrane base membrane, and then forming the ceramic coating on the surface of the polyolefin microporous membrane base membrane subjected to the fluorination treatment; the fluorination treatment comprises subjecting the base film to fluorine gas at a concentration of 0.05% for 20 to 60 seconds.
The concentration of the fluorine gas and the treatment time are mainly for forming a fluorinated layer uniformly dispersed on the surface of the micropores of the polyolefin microporous membrane, and therefore, the concentration of the fluorine gas and the treatment time can be adjusted depending on the treatment target.
The key point of the application lies in that research discovers that after the polyolefin microporous membrane is subjected to fluorination treatment, the polarity and the wettability of the surface of the polyolefin microporous membrane can be improved, the surface bonding force between the polyolefin microporous membrane and a ceramic coating is improved, the ceramic coating is uniformly coated and is not easy to fall off, and therefore the puncture resistance and the tensile strength of the battery diaphragm are improved; meanwhile, the fluorination treatment can initiate the entanglement of molecular chains, and further improve the puncture resistance and the tensile strength. In one embodiment of the present invention, the fluorination process is performed in a sealed fluorination process chamber, and the temperature may be room temperature, and the pressure in the sealed fluorination process chamber is standard atmospheric pressure.
Preferably, the base film is one of a polyethylene microporous film, a polypropylene microporous film and a polyethylene polypropylene composite microporous film.
It should be noted that, the present application takes a polyolefin microporous membrane as a research object, wherein a polyethylene microporous membrane, a polypropylene microporous membrane, and a polyethylene polypropylene composite microporous membrane are relatively common polyolefin microporous membranes, and it is not excluded that the preparation method of the present application is also applicable to other polyolefin microporous membranes.
Preferably, the ceramic coating is an alumina coating.
It is noted that in one implementation of the present application, the ceramic coating is preferably an alumina coating; it is understood that the key to the present application is to improve the adhesion of the surface of the polyolefin microporous membrane to the ceramic coating by performing fluorination treatment on the surface of the polyolefin microporous membrane, and the ceramic coating is not limited to the alumina coating, and other materials such as titanium dioxide, silicon dioxide, zirconium oxide, aluminum hydroxide, magnesium hydroxide, etc. can be used in the present application.
The other side of the application discloses a polyolefin microporous membrane with a ceramic coating prepared by the preparation method.
The application also discloses an application of the ceramic coating polyolefin microporous membrane in a battery diaphragm.
The other side of the application discloses a battery diaphragm of the ceramic coating polyolefin microporous membrane.
The preparation method can be understood that the prepared polyolefin microporous membrane with the ceramic coating has excellent puncture resistance and tensile strength, so that the polyolefin microporous membrane can be used as a battery diaphragm in a lithium ion battery, and can avoid battery quality problems or potential safety hazards caused by shedding of the ceramic coating or uneven coating.
The other side of the application discloses a fluorinated polyolefin microporous membrane prepared by the preparation method, and the fluorinated polyolefin microporous membrane comprises one of a fluorinated polyethylene microporous membrane, a fluorinated polypropylene microporous membrane and a fluorinated polyethylene polypropylene composite microporous membrane.
It should be noted that the fluorinated polyolefin microporous membrane of the present application is actually a product of fluorination treatment of a polyolefin microporous membrane according to the preparation method of the present application; in actual production, the polyolefin microporous membrane is coated with the ceramic coating and can be produced in downstream production, so that the fluorinated polyolefin microporous membrane has better polarity and wettability compared with the conventional untreated polyolefin microporous membrane, and the quality of the ceramic coating can be guaranteed.
Due to the adoption of the technical scheme, the beneficial effects of the application are as follows:
according to the preparation method of the polyolefin microporous membrane with the ceramic coating, the polyolefin microporous membrane is subjected to fluorination treatment in advance, then the ceramic coating is coated, the polarity and the wettability of the surface of the polyolefin microporous membrane can be effectively improved through the fluorination treatment, and the surface bonding force of the polyolefin microporous membrane and the ceramic coating is improved, so that the ceramic coating is uniformly coated and is not easy to fall off. And the fluorination treatment induces the molecular chain of the polyolefin microporous membrane to be entangled, so that the puncture resistance and the tensile strength are further improved.
Drawings
FIG. 1 is an electron microscope scan of a polyolefin microporous membrane before fluorination treatment in an example of the present application;
FIG. 2 is an electron microscope scan of a polyolefin microporous membrane after fluorination treatment in the examples of the present application.
Detailed Description
The present application is described in further detail below with reference to specific embodiments and the attached drawings. The following examples are intended to be illustrative of the present application only and should not be construed as limiting the present application.
Examples
This example was tested with a commercially available PP-based membrane ZD25, as follows:
the PP-based film ZD25 was developed, and placed in a sealed fluorination treatment chamber at room temperature under a pressure of 1 atmosphere in which the fluorine gas was contained at a volume concentration of 0.05% for 20 seconds to obtain a fluorinated base film ZD25 of this example.
The characteristics of base film ZD25 and fluorinated base film ZD25 without fluorination treatment, including thickness, air permeability, tensile strength MD, puncture strength, shrinkage MD, shrinkage TD, were tested separately.
The air permeability is tested by adopting an Asahi air permeability instrument according to the GB/T458-.
The test method of the tensile strength MD comprises the following steps: the samples were cut into rectangular 2X 10cm strips and the experimental data were read using an MTS universal tester against GB/T12027-2004.
The puncture strength test method comprises the following steps: and (3) reading experimental data by adopting a puncture clamp of an MTS universal tester and contrasting with a GB/T21302-2007 standard test.
The test methods for shrinkage MD and shrinkage TD were: the sample was cut into a 10X 10cm square, placed in an oven at 105 ℃ and baked for 2 hours, and the results were calculated according to GB/T12027-2004 after being taken out.
The test results are shown in table 1.
TABLE 1 test results for base films and fluorinated base films
| Test items | Basement membrane ZD25 | Fluorinated basement membrane ZD25 |
| Thickness (μm) | 24.9 | 25 |
| Breathability (s/100mL) | 325 | 326 |
| Tensile Strength MD (Kg f/cm)2) | 1403 | 1437 |
| Puncture strength (1mm flat head/g) | 530 | 589 |
| Shrinkage ratio MD (%) at 105 ℃ for 2 hours | 1.4 | 0.7 |
| Shrinkage TD (%) (2 h) at 105 ℃ | 0.1 | 0.1 |
The results in table 1 show that fluorinated base film ZD25 obtained by the fluorination treatment has improved tensile strength and puncture strength, reduced heat shrinkage, and improved stability.
In addition, observation of base film ZD25 without fluorination treatment and base film ZD25 by electron microscope scanning showed that base film ZD25 without fluorination treatment was shown in fig. 1 and fig. 2, and base film ZD25 was shown in fig. 2. It can be seen that the fluorination treatment initiated the molecular chain entanglement of the microporous polyolefin membrane, which was favorable for improving the puncture resistance and tensile strength, which is consistent with the results in Table 1.
In addition, in this example, the dyne energy of ZD25 basement membrane before and after the fluorination treatment was tested by a dyne pen to show the influence of the fluorination treatment on the polarity and wettability of the basement membrane surface. The test result shows that the test solution is distributed in a point shape on the base film ZD25 and cannot be well covered on the base film ZD25, which is consistent with the fact that polypropylene has no polarity and surface wettability; and for the fluorinated base film ZD25 after the fluorination treatment, the test solution can uniformly cover the surface of the fluorinated base film, almost no punctate liquid drops exist, so that the surface polarity and the wettability of the base film are improved after the fluorination treatment, and a foundation is laid for the coating of the ceramic coating.
Further, in this example, base films ZD25 and ZD25 which were not subjected to the fluorination treatment were subjected to ceramic coating, respectively, to prepare battery separators, and the performances of both separators were tested. The method comprises the following specific steps:
the ceramic slurry used in this example was a conventional alumina ceramic slurry, the main materials being alumina, water, thickener and binder, and a small amount of dispersant. Wherein, the weight ratio of the alumina, the water, the thickening agent, the bonding agent and the dispersing agent is 1/1.42/0.0099/0.05/0.03. Uniformly dispersing all the components into water to obtain ceramic slurry, respectively coating the ceramic slurry on a base film ZD25 and a fluorinated base film ZD25 which are not subjected to fluorination treatment, and drying to obtain two ceramic coating diaphragms.
After the membranes were prepared, comparative tests were performed on the thickness, air permeability, tensile strength MD, puncture strength, shrinkage MD, shrinkage TD and peel strength of the two ceramic coated membranes in this example.
Test methods for air permeability, tensile strength MD, puncture strength, shrinkage MD, shrinkage TD refer to the previous tests for base film ZD25 and fluorinated base film ZD 25. The peel strength was measured by cutting a sample coated with the ceramic coating to a width of 2cm and a length of 20 cm. And flatly pasting the cut sample on a pasted double-sided adhesive tape ruler with the width of 2cm and the length of 8cm, immediately mounting the ruler on a machine for measurement after pasting, wherein the testing speed is 300mm/min, and the testing distance is 200 mm. The results of the tests are shown in Table 2.
TABLE 2 results of tests on base films and fluorinated base films after application of ceramic coatings
The results in table 2 show that the peel strength of the ceramic coating is significantly improved after the fluorination treatment, i.e. the surface adhesion between the base film and the ceramic coating is improved; moreover, the ceramic coating is uniform, the air permeability, the tensile strength and the puncture strength are improved to different degrees, and the thermal stability is better.
The foregoing is a more detailed description of the present application in connection with specific embodiments thereof, and it is not intended that the present application be limited to the specific embodiments thereof. For those skilled in the art to which the present application pertains, several simple deductions or substitutions can be made without departing from the concept of the present application, and all should be considered as belonging to the protection scope of the present application.
Claims (5)
1. A preparation method of a polyolefin microporous membrane with a ceramic coating is characterized by comprising the following steps: the method comprises the following steps of carrying out fluorination treatment on a polyolefin microporous membrane base film, and then forming a ceramic coating on the surface of the fluorinated polyolefin microporous membrane base film; the fluorination treatment comprises placing the base film in fluorine gas with the concentration of 0.05% to react for 20-60 seconds;
the polyolefin microporous membrane base film is one of a polyethylene microporous membrane, a polypropylene microporous membrane and a polyethylene polypropylene composite microporous membrane, and the ceramic coating is an alumina coating.
2. The ceramic-coated polyolefin microporous membrane prepared by the preparation method according to claim 1.
3. Use of the ceramic coated polyolefin microporous membrane according to claim 2 in a battery separator.
4. A battery separator comprising the ceramic coated polyolefin microporous membrane of claim 2.
5. The fluorinated polyolefin microporous membrane prepared by the preparation method according to claim 1, wherein the fluorinated polyolefin microporous membrane comprises one of a fluorinated polyethylene microporous membrane, a fluorinated polypropylene microporous membrane and a fluorinated polyethylene polypropylene composite microporous membrane.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102088067A (en) * | 2009-12-04 | 2011-06-08 | 索尼公司 | Diaphragm and battery |
| CN102496745A (en) * | 2011-11-28 | 2012-06-13 | 泉州劲鑫电子有限公司 | High-temperature nickel-metal hydride battery and manufacturing method thereof |
| CN104617328A (en) * | 2014-07-10 | 2015-05-13 | 天津东皋膜技术有限公司 | Long-life lithium ion secondary battery and manufacturing method thereof |
| CN105428575A (en) * | 2015-12-04 | 2016-03-23 | 中国制浆造纸研究院衢州分院 | Preparation method for plasma-induced grafting acrylic acid modified nickel-metal hydride battery diaphragm paper |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2001068088A (en) * | 1999-08-31 | 2001-03-16 | Sanyo Electric Co Ltd | Nonaqueous electrolyte secondary battery |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102088067A (en) * | 2009-12-04 | 2011-06-08 | 索尼公司 | Diaphragm and battery |
| CN102496745A (en) * | 2011-11-28 | 2012-06-13 | 泉州劲鑫电子有限公司 | High-temperature nickel-metal hydride battery and manufacturing method thereof |
| CN104617328A (en) * | 2014-07-10 | 2015-05-13 | 天津东皋膜技术有限公司 | Long-life lithium ion secondary battery and manufacturing method thereof |
| CN105428575A (en) * | 2015-12-04 | 2016-03-23 | 中国制浆造纸研究院衢州分院 | Preparation method for plasma-induced grafting acrylic acid modified nickel-metal hydride battery diaphragm paper |
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