CN113809477A - Closed-pore characteristic battery diaphragm and preparation method and application thereof - Google Patents
Closed-pore characteristic battery diaphragm and preparation method and application thereof Download PDFInfo
- Publication number
- CN113809477A CN113809477A CN202010481133.0A CN202010481133A CN113809477A CN 113809477 A CN113809477 A CN 113809477A CN 202010481133 A CN202010481133 A CN 202010481133A CN 113809477 A CN113809477 A CN 113809477A
- Authority
- CN
- China
- Prior art keywords
- closed
- organic polymer
- battery separator
- diaphragm
- coating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- 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
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Cell Separators (AREA)
Abstract
The invention discloses a closed-pore characteristic battery diaphragm and a preparation method and application thereof; the closed-cell battery diaphragm comprises a diaphragm and a modified organic polymer coating coated on one side or two sides of the diaphragm, wherein the modified organic polymer coating comprises organic polymer powder and a grafting agent containing C ═ C double bonds. The modified organic polymer coating grafts and combines the coating into a whole at high temperature, thereby achieving the effect of completely closing and plugging the hole and greatly improving the hole closing performance of the diaphragm.
Description
Technical Field
The invention belongs to the field of battery diaphragm materials, and particularly relates to a closed-pore battery diaphragm and a preparation method and application thereof.
Background
Polyolefin microporous membranes are used for microfiltration membranes, battery separators, capacitor separators, fuel cell materials, and the like. Among these applications, when used as a battery separator, particularly a lithium ion battery separator, the polyolefin microporous membrane is required to have excellent ion permeability, excellent mechanical strength, and the like. In order to ensure the safety of batteries, separators for high-capacity batteries in recent years are required to have "low closed-cell temperature characteristics", "high rupture temperature characteristics", and "low heat shrinkability". In addition, in order to reduce variations in battery characteristics, it is also required to reduce variations in film thickness.
The "low closed cell temperature characteristic" is a function of ensuring the safety of the battery by melting the separator to form a film covering the electrode and blocking the current when the inside of the battery is overheated due to an overcharge state or the like. It is known that in the case of a polyethylene microporous membrane, the closed cell temperature, i.e., the temperature at which the melt characteristic is exhibited, is about 140 ℃. However, in order to prevent runaway reaction and the like in the battery as early as possible, it is preferable that the melting temperature is lower.
In the prior art, an organic polymer coating is coated on the surface of a diaphragm, but the common organic polymer coating cannot effectively improve the closed-cell performance of the diaphragm.
Disclosure of Invention
In view of the above, the present invention provides a battery separator with closed-cell characteristics, and a preparation method and an application thereof, wherein the closed-cell performance of the battery separator is effectively improved by an organic polymer coating.
In order to achieve the purpose, the invention provides the following technical scheme:
the invention provides a closed-cell-characteristic battery diaphragm which comprises a diaphragm and a modified organic polymer coating coated on one side or two sides of the diaphragm, wherein the modified organic polymer coating comprises organic polymer powder and a grafting agent containing C ═ C double bonds.
As a preferred technical solution, the organic polymer powder includes one or more of high-density polyethylene, low-density polyethylene, polypropylene, polyethylene-propylene copolymer, polyethylene-butene copolymer, polyethylene-hexene copolymer, polyethylene-octene copolymer, polystyrene-butene-styrene copolymer, polystyrene-ethylene-butene-styrene copolymer, polystyrene, polyphenylene oxide, polysulfone, polycarbonate, polyester, polyamide, polyurethane, polyacrylate, polyvinylidene chloride, polyolefin ionomer, polymethylpentene, and hydrogenated cyclopentadiene oligomer.
As a preferred technical scheme, the particle size of the organic polymer powder is 0.1-10 μm, the melting point is 110-140 ℃, the melt index under 190 ℃ and 21.6KG is 0.4-10, and the enthalpy is less than or equal to 170J/g.
As a preferred technical scheme, the grafting agent containing the C ═ C double bond comprises one or more of gamma-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane and vinyltriethoxysilane.
In a preferred embodiment, the modified organic polymer coating layer contains a grafting agent having a C ═ C double bond in an amount of 0.2 to 5 wt% based on the weight of the organic polymer powder.
As a preferable technical scheme, the thickness of the modified organic polymer coating is 0.1-10 mu m, and the surface density of the coating is 0.05-5g/m2。
As a preferable technical scheme, the diaphragm is a polyethylene film, a polypropylene film or a polyethylene and polypropylene composite film with the thickness of 5-40 μm and the porosity of 20-80%.
The invention also provides a preparation method of the battery diaphragm with the closed-cell characteristic, which comprises the following steps:
(1) mixing organic polymer powder with water, adding a grafting agent containing C ═ C double bonds, grinding, stirring and dispersing to obtain modified organic polymer dispersion liquid;
(2) diluting the modified organic polymer dispersion liquid prepared in the step (1) to prepare coating slurry;
(3) sending the diaphragm into a coating device, and coating by using the coating slurry prepared in the step (2);
(4) and (4) drying and rolling the diaphragm coated in the step (3) to obtain the closed-pore battery diaphragm.
The invention also provides an application of the battery diaphragm with the closed-cell characteristic: a lithium ion battery comprising a positive electrode, a negative electrode, an electrolyte, and a battery separator between the positive electrode and the negative electrode, the battery separator comprising the closed-cell battery separator.
The invention has the beneficial effects that:
the organic polymer is modified by adopting the grafting agent containing C ═ C double bonds, and the organic polymer is used as a modified organic polymer coating of the diaphragm, the modified organic polymer coating can initiate C ═ C double bond polymerization reaction at high temperature, a cross-linked network framework is formed between organic polymer chains, and the coating is grafted and combined into a whole, so that the effect of completely closing and plugging the hole is achieved, and the hole closing performance of the diaphragm is greatly improved.
Detailed Description
The present invention is further described with reference to specific examples to enable those skilled in the art to better understand the present invention and to practice the same, but the examples are not intended to limit the present invention.
Example 1:
(1) mixing LDPE powder (melting point of 115 ℃, melt index of 7.5 at 190 ℃ and under 21.6KG, enthalpy of 150J/g) and water according to a mass ratio of 4:6, adding a gamma-methacryloxypropyltrimethoxysilane grafting agent accounting for 1% of the mass of the LDPE powder, grinding for 0.5h by using a horizontal grinding machine, and dispersing for 2h at a stirring speed of 1000r/min by using a stirrer to obtain a grafted LDPE dispersion liquid;
(2) diluting the grafted LDPE dispersion liquid prepared in the step (1) with a sodium carboxymethylcellulose solution until the LDPE content is 0.6 wt%, and then adding a dispersing agent, a polyacrylic acid adhesive emulsion and a fluorocarbon surfactant to prepare coating slurry;
(3) taking a polyolefin diaphragm, feeding the diaphragm into a coating device, and performing double-sided coating by using the coating slurry prepared in the step (2);
(4) and (4) drying and rolling the diaphragm coated in the step (3) to obtain the modified LDPE coating diaphragm.
Example 2:
the present embodiment is different from embodiment 1 in that: the LDPE was replaced by a polyethylene-propylene copolymer (particle size 1.8 μm, melting point 125 ℃, melt index 4 at 190 ℃ and 21.6KG, enthalpy 160J/g).
Comparative example 1:
(1) mixing LDPE powder (melting point of 115 ℃, melt index of 7.5 at 190 ℃ and under 21.6KG, enthalpy of 150J/g) and water according to a mass ratio of 4:6, then grinding for 0.5h by using a horizontal grinding machine, and then dispersing for 2h at a stirring speed of 1000r/min by using a stirrer to obtain LDPE dispersion liquid;
(2) diluting the LDPE dispersion liquid prepared in the step (1) with a sodium carboxymethylcellulose solution until the content of LDPE is 0.6 wt%, and then adding a dispersing agent, a polyacrylic acid adhesive emulsion and a fluorocarbon surfactant to prepare coating slurry;
(3) taking a polyolefin diaphragm, feeding the diaphragm into a coating device, and performing double-sided coating by using the coating slurry prepared in the step (2);
(4) and (4) drying and rolling the diaphragm coated in the step (3) to obtain the LDPE coating diaphragm.
Comparative example 2:
the difference from comparative example 1 is that: the LDPE is replaced by a polyethylene-propylene copolymer (melting point 125 ℃, melt index 4 at 190 ℃ and 21.6KG, enthalpy 160J/g).
The separators obtained in examples 1-2 and comparative examples 1-2 were subjected to performance tests under the same conditions, and the results are shown in table 1.
TABLE 1 comparison of results of membrane Performance tests
From the performance test data in table 1, the closed cell temperature of example 1 is 119 ℃, the temperature difference of the closed cell process is 29 ℃, and compared with comparative example 1, the closed cell temperature is stable, and the duration of the closed cell process is long; the closed cell temperature of example 2 is 127 ℃, the temperature difference of the closed cell process is 33 ℃, and compared with the comparative example 2, the closed cell temperature is stable, and the closed cell process has long duration.
The above experimental data show that the common organic polymer coating cannot effectively improve the closed pore performance of the diaphragm; the modified organic polymer coating grafts and combines the coating into a whole at high temperature, thereby achieving the effect of completely closing and plugging the hole and greatly improving the hole closing performance of the diaphragm.
The above-mentioned embodiments are merely preferred embodiments for fully illustrating the present invention, and the scope of the present invention is not limited thereto. The equivalent substitution or change made by the technical personnel in the technical field on the basis of the invention is all within the protection scope of the invention. The protection scope of the invention is subject to the claims.
Claims (9)
1. A closed cell battery separator, characterized by: the modified organic polymer coating comprises organic polymer powder and a grafting agent containing C ═ C double bonds.
2. The closed-cell battery separator of claim 1, wherein: the organic polymer powder comprises one or more of high-density polyethylene, low-density polyethylene, polypropylene, polyethylene-propylene copolymer, polyethylene-butylene copolymer, polyethylene-hexene copolymer, polyethylene-octene copolymer, polystyrene-butylene-styrene copolymer, polystyrene-ethylene-butylene-styrene copolymer, polystyrene, polyphenyl ether, polysulfone, polycarbonate, polyester, polyamide, polyurethane, polyacrylate, polyvinylidene chloride, polyolefin ionomer, polymethylpentene and hydrogenated cyclopentadiene oligomer.
3. The closed-cell battery separator of claim 2, wherein: the particle size of the organic polymer powder is 0.1-10 μm, the melting point is 110-140 ℃, the melt index under 190 ℃ and 21.6KG is 0.4-10, and the enthalpy is less than or equal to 170J/g.
4. The closed-cell battery separator of claim 1, wherein: the grafting agent containing C ═ C double bonds comprises one or more of gamma-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane and vinyltriethoxysilane.
5. The closed-cell battery separator of claim 1, wherein: in the modified organic polymer coating, the mass of the grafting agent containing C ═ C double bonds accounts for 0.2-5 wt% of the mass of the organic polymer powder.
6. The closed-cell battery separator of claim 1, wherein: the thickness of the modified organic polymer coating is 0.1-10 mu m, and the surface density of the coating is 0.05-5g/m2。
7. The closed-cell battery separator of claim 1, wherein: the diaphragm is a polyethylene film, a polypropylene film or a polyethylene and polypropylene composite film with the thickness of 5-40 mu m and the porosity of 20-80%.
8. The method for producing a closed-cell battery separator according to any one of claims 1 to 7, wherein: the method comprises the following steps:
(1) mixing organic polymer powder with water, adding a grafting agent containing C ═ C double bonds, grinding, stirring and dispersing to obtain modified organic polymer dispersion liquid;
(2) diluting the modified organic polymer dispersion liquid prepared in the step (1) to prepare coating slurry;
(3) sending the diaphragm into a coating device, and coating by using the coating slurry prepared in the step (2);
(4) and (4) drying and rolling the diaphragm coated in the step (3) to obtain the closed-pore battery diaphragm.
9. A lithium ion battery comprising a positive electrode, a negative electrode, an electrolyte, and a battery separator between the positive electrode and the negative electrode, wherein: the battery separator comprising the closed-cell battery separator of any of claims 1 to 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010481133.0A CN113809477A (en) | 2020-05-31 | 2020-05-31 | Closed-pore characteristic battery diaphragm and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010481133.0A CN113809477A (en) | 2020-05-31 | 2020-05-31 | Closed-pore characteristic battery diaphragm and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113809477A true CN113809477A (en) | 2021-12-17 |
Family
ID=78891903
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010481133.0A Pending CN113809477A (en) | 2020-05-31 | 2020-05-31 | Closed-pore characteristic battery diaphragm and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113809477A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116435707A (en) * | 2023-06-09 | 2023-07-14 | 宁德新能源科技有限公司 | Electrochemical device and electronic device |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103066227A (en) * | 2012-12-26 | 2013-04-24 | 中科院广州化学有限公司 | Flexible composite ceramic membrane with low temperature closed-cell performance and good dimensional stability |
| CN103441229A (en) * | 2013-07-23 | 2013-12-11 | 清华大学 | Battery separator and preparation method thereof |
| CN105047845A (en) * | 2015-06-19 | 2015-11-11 | 深圳市星源材质科技股份有限公司 | High-dielectric constant nano-composite coating diaphragm and preparation method thereof |
| CN106920912A (en) * | 2017-04-14 | 2017-07-04 | 上海恩捷新材料科技股份有限公司 | A kind of preparation method of lithium ion battery barrier film |
| CN110048057A (en) * | 2019-03-25 | 2019-07-23 | 重庆云天化纽米科技股份有限公司 | Surface modified PMMA/PVDF mixing coating composite diaphragm for lithium battery and preparation method thereof |
| CN110326128A (en) * | 2018-01-31 | 2019-10-11 | 株式会社Lg化学 | Diaphragm includes the lithium secondary battery of diaphragm and its manufacturing method |
| CN110635092A (en) * | 2019-08-28 | 2019-12-31 | 重庆云天化纽米科技股份有限公司 | Polar polyolefin separator and preparation method thereof |
| CN111108627A (en) * | 2018-08-17 | 2020-05-05 | 株式会社Lg化学 | Crosslinked polyolefin separator and method for producing same |
-
2020
- 2020-05-31 CN CN202010481133.0A patent/CN113809477A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103066227A (en) * | 2012-12-26 | 2013-04-24 | 中科院广州化学有限公司 | Flexible composite ceramic membrane with low temperature closed-cell performance and good dimensional stability |
| CN103441229A (en) * | 2013-07-23 | 2013-12-11 | 清华大学 | Battery separator and preparation method thereof |
| CN105047845A (en) * | 2015-06-19 | 2015-11-11 | 深圳市星源材质科技股份有限公司 | High-dielectric constant nano-composite coating diaphragm and preparation method thereof |
| CN106920912A (en) * | 2017-04-14 | 2017-07-04 | 上海恩捷新材料科技股份有限公司 | A kind of preparation method of lithium ion battery barrier film |
| CN110326128A (en) * | 2018-01-31 | 2019-10-11 | 株式会社Lg化学 | Diaphragm includes the lithium secondary battery of diaphragm and its manufacturing method |
| CN111108627A (en) * | 2018-08-17 | 2020-05-05 | 株式会社Lg化学 | Crosslinked polyolefin separator and method for producing same |
| US20200266410A1 (en) * | 2018-08-17 | 2020-08-20 | Lg Chem, Ltd. | Crosslinked Polyolefin Separator and Manufacturing Method Thereof |
| CN110048057A (en) * | 2019-03-25 | 2019-07-23 | 重庆云天化纽米科技股份有限公司 | Surface modified PMMA/PVDF mixing coating composite diaphragm for lithium battery and preparation method thereof |
| CN110635092A (en) * | 2019-08-28 | 2019-12-31 | 重庆云天化纽米科技股份有限公司 | Polar polyolefin separator and preparation method thereof |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116435707A (en) * | 2023-06-09 | 2023-07-14 | 宁德新能源科技有限公司 | Electrochemical device and electronic device |
| CN116435707B (en) * | 2023-06-09 | 2023-09-19 | 宁德新能源科技有限公司 | Electrochemical device and electronic device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4792688B2 (en) | Method for producing separator for non-aqueous electrolyte secondary battery | |
| EP2755256B1 (en) | Slurry for secondary batteries | |
| JP6193333B2 (en) | Separator and manufacturing method thereof | |
| KR102314215B1 (en) | Separator with improved heat-resistance and air permeability and secondary battery comprising the same | |
| KR19990088434A (en) | Polymeric membranes having electrolytes and secondary cells using the same | |
| CN113169417A (en) | Separator for lithium secondary battery and lithium secondary battery including the same | |
| CN109841785A (en) | A kind of battery diaphragm and preparation method thereof and the lithium ion battery comprising the diaphragm | |
| JP2018163872A (en) | Separator for nonaqueous secondary battery, and nonaqueous secondary battery | |
| CN112909430A (en) | Lithium ion battery diaphragm and preparation method thereof and lithium ion battery | |
| JP2014531707A (en) | Electrode forming composition | |
| CN101849315B (en) | Lithium ion secondary battery | |
| JP5170018B2 (en) | Nonaqueous electrolyte secondary battery separator | |
| CN112615111A (en) | High-liquid-retention self-repairing diaphragm, preparation method thereof and lithium ion battery | |
| KR20180101182A (en) | Separator for non-aqueous secondary battery, and non-aqueous secondary battery | |
| CN114374055A (en) | Battery separator with high mechanical strength, high flame retardance and high adhesion and preparation method thereof | |
| KR101918445B1 (en) | Nonaqueous electrolyte secondary battery separator | |
| CN113809477A (en) | Closed-pore characteristic battery diaphragm and preparation method and application thereof | |
| US20220247038A1 (en) | Secondary batteries | |
| JP2016111002A (en) | Separator for non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery | |
| CN113036308A (en) | Lithium ion battery composite gel diaphragm and preparation method and application thereof | |
| WO2023179550A1 (en) | Composite oil-based separator and preparation method therefor, and secondary battery | |
| EP3394917A1 (en) | Composite material | |
| US11394029B2 (en) | Slurry composition for non-aqueous secondary battery functional layers, non-aqueous secondary battery functional layer, and non-aqueous secondary battery | |
| CN115863907A (en) | Lithium battery diaphragm and preparation method and application thereof | |
| JP2019029315A (en) | Separator for nonaqueous secondary battery and nonaqueous secondary battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |