CN109065804B - Water-based ceramic/PVDF (polyvinylidene fluoride) mixed coating slurry as well as preparation method and application thereof - Google Patents
Water-based ceramic/PVDF (polyvinylidene fluoride) mixed coating slurry as well as preparation method and application thereof Download PDFInfo
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Abstract
The invention provides a water-based ceramic/PVDF mixed coating slurry, a preparation method and application thereof, wherein high-purity water, perfluoroalkyl dispersing agents, tert-butyl hydroperoxide and acetone are uniformly mixed, and then vinylidene fluoride and hexafluoropropylene gas are continuously introduced to obtain a water-based PVDF emulsion; dispersing the ceramic material and the first dispersant in deionized water, adding the thickening agent and the adhesive, the aqueous PVDF emulsion and the wetting agent, and uniformly mixing to obtain the slurry. Coating the prepared water-based ceramic/PVDF mixed coating slurry on a polyethylene diaphragm to obtain a wet film; and drying to obtain the water-based ceramic/PVDF mixed coating membrane. The invention aims to remarkably improve the dispersion uniformity of the ceramic/PVDF blended slurry, improve the uniformity of the coating of the ceramic/PVDF mixed coating diaphragm, and remarkably improve the comprehensive performance of the lithium ion battery diaphragm by combining the characteristics of the ceramic material and the PVDF material.
Description
Technical Field
The invention relates to the technical field of battery diaphragm materials, in particular to water-based ceramic/PVDF mixed coating slurry and a preparation method and application thereof.
Background
The lithium ion battery diaphragm is mainly divided into a single-layer microporous membrane, a composite membrane, a blended membrane and a non-woven fabric membrane. The coated separator is one of the composite membranes. The ternary battery and the wet coating diaphragm are matched for use in the current market, and the demand of the wet coating diaphragm is continuously increased along with the continuous improvement of the market proportion of the ternary battery. The coating of the separator is mainly classified into inorganic ceramic coating and polymer coating, and the structure and properties of the coating layer are greatly changed according to the difference of raw materials and processes, thereby affecting the performance of the battery. The battery performance including chemical properties such as oxidation resistance, adhesion, electrolyte wettability, etc. is determined by the properties of the coating material itself; the structure of the coating, such as micropore morphology, porosity, consistency, etc., is determined by the coating process; thermal stability, moisture, electrolyte retention, etc., which are related to both the raw material properties and the coating process. According to the requirements of different batteries, products with different properties can be flexibly designed by changing raw materials and technological processes.
The ceramic particle coating diaphragm takes a PE or PP film as a substrate, and the surface of the ceramic particle coating diaphragm is coated with a layer of Al2O3、SiO2、Mg(OH)2Or other inorganic ceramic particles having excellent heat resistance. The main process of ceramic coating comprises the following steps: uniformly stirring deionized water, a ceramic material, a dispersing agent, an adhesive and a slurry regulator (a thickening agent, a surfactant and the like) to obtain the slurry for coating. Coating on a coating machine, and drying to obtain the coating diaphragm. Factors such as coating mode, temperature and humidity of workshop environment, temperature of an oven and the like have certain influence on product performance. The advantages of the ceramic coated separator are as follows: 1. the thermal stability of the diaphragm is improved, the ceramic coated diaphragm has small shrinkage at high temperature, internal short circuit caused by the shrinkage of the diaphragm can be avoided, and the safety performance of the battery is obviously improved; 2. secondly, increaseThe wettability of the diaphragm on the electrolyte is favorable for reducing the internal resistance of the battery and improving the discharge power; 3. moreover, the oxidation of the diaphragm can be prevented or reduced, which is beneficial to matching with the use of a high-voltage anode and prolonging the cycle life of the battery.
PVDF, i.e., polyvinylidene fluoride, is a white powdery semi-crystalline polymer, has a melting point of 170 ℃ and a thermal decomposition temperature of over 316 ℃, and has excellent chemical corrosion resistance, oxidation resistance, flexibility, high tensile strength and high impact strength. The PVDF coating membrane has the characteristics of low internal resistance, good mechanical property, good chemical and electrochemical stability and the like. PVDF can provide certain ionic conductivity after swelling in the electrolyte. Due to the self-connectivity of PVDF, positive and negative materials can be connected together, the transmission distance of lithium ions between the positive and negative materials is greatly shortened, and the bonding performance is just the same as that of a brick after the battery is disassembled, so that the assembly efficiency in the battery assembly process is greatly improved. Without such a tie layer, subsequent reconditioning is required after some membrane misalignment during cell assembly, but the PVDF coated membrane reduces this effort. Because it shortens the transmission distance of positive and negative ions, the battery has a series of excellent performances, such as cycle performance, and meanwhile, because of being tightly attached to the positive and negative electrodes, the battery is endowed with certain safety. At present, more and more battery core manufacturers select a PVDF coating film in the battery design process, in particular to high-end energy storage batteries and automobile power batteries.
Mix coating is a new coating process developed in recent years, which is mainly to prepare uniform slurry of PVDF and ceramic materials and then coat the slurry. The mixed coating process can combine the advantages of ceramic coating and PVDF coating, and can obviously improve the comprehensive performance of the diaphragm. However, PVDF belongs to a hydrophobic polymer material, and ceramics is a hydrophilic material, and both are difficult to disperse in the same system. Even if the conventional technology can disperse the coating material, the coating material is difficult to disperse uniformly, so that the particles of the coating of the mixed coating diaphragm are not uniformly dispersed, and the nonuniform coating can cause the nonuniform local current density of the battery in the charging and discharging process, so that the structure of the electrode material is easier to damage in the circulating process, and the circulating life of the lithium ion battery is greatly shortened.
Disclosure of Invention
Aiming at the technical problems in the related art, the invention provides a water-based ceramic/PVDF mixed coating slurry and a preparation method thereof, and a coating diaphragm adopting the slurry and a preparation method thereof, aiming at remarkably improving the dispersion uniformity of the ceramic/PVDF mixed coating slurry, improving the uniformity of a coating of the ceramic/PVDF mixed coating diaphragm, and remarkably improving the comprehensive performance of a lithium ion battery diaphragm by combining the characteristics of a ceramic material and a PVDF material.
In order to achieve the technical purpose, the technical scheme of the invention is realized as follows:
on one hand, the invention provides a preparation method of water-based ceramic/PVDF mixed coating slurry, which comprises the following specific processes:
1) stirring and mixing high-purity water, perfluoroalkyl dispersing agents, tert-butyl hydroperoxide and acetone uniformly in a nitrogen atmosphere, heating, continuously introducing vinylidene fluoride monomer and hexafluoropropylene monomer gas, controlling reaction pressure, filtering and washing after the reaction is finished, and adjusting solid content to obtain a water-based PVDF emulsion;
2) dispersing the ceramic material and the first dispersant into deionized water, adding a thickening agent and an adhesive for dispersion, adding the aqueous PVDF emulsion obtained in the step 1) and a wetting agent while stirring, and uniformly mixing to obtain the aqueous ceramic/PVDF mixed coating slurry.
Further, in the step 1), the ratio of the high-purity water, the perfluoroalkyl dispersant, the tert-butyl hydroperoxide, the acetone, the vinylidene fluoride monomer and the hexafluoropropylene monomer is 150-200: 0.5-1: 0.3-0.9: 0.8-1.7: 60:40 by weight.
Further, in the step 1), the rotation speed of the stirring and mixing is 70rpm/min, and the stirring time is 1-5 h.
Further, in the step 1), the heating temperature is 60-100 ℃.
Further, in the step 1), the reaction pressure is controlled by adjusting the gas flow, the pressure is controlled to be 1.5-4.0 MPa, and the reaction time is 8-15 h.
Further, in the step 1), deionized water is adopted for washing for 3-5 times.
Further, in the step 1), the adjusting of the solid content means that deionized water is used for preparing an aqueous PVDF polymer emulsion with a mass fraction of 20%.
Further, in the step 2), the ratio of the ceramic material, the first dispersing agent, the deionized water, the thickening agent, the adhesive, the aqueous PVDF emulsion obtained in the step 1) and the wetting agent is 10-30: 0.01-2: 45: 0.1-0.5: 7-15: 10-40: 0.05-0.5 in parts by weight.
Further, the ceramic material and the first dispersing agent in the step 2) are dispersed in deionized water and stirred for 0.5-8 hours.
Further, the stirring time for dispersing the thickening agent and the adhesive in the step 2) is 2-10 hours.
Further, the stirring time of the aqueous PVDF emulsion obtained in the step 1) in the step 2) and the wetting agent after the aqueous PVDF emulsion and the wetting agent are added is 3-9 hours.
Further, the perfluoroalkyl dispersing agent comprises one or more of perfluoroalkyl ethyl acrylate, ammonium perfluorooctanoate, perfluoroheptanoic acid and sodium perfluorododecyl sulfonate.
Further, the ceramic material comprises one or more of alumina, boehmite, silica, magnesium hydroxide, titania.
Further, the first dispersing agent comprises one or more of maleic anhydride-vinyl acetate, styrene-maleic anhydride, polyethylene glycol, sodium polyacrylate and potassium polyacrylate.
Further, the thickening agent comprises one or more of hydroxyethyl cellulose, methyl hydroxyethyl cellulose, sodium carboxymethyl cellulose, polyacrylamide and sodium alginate.
Further, the adhesive comprises one or more of styrene-butadiene latex, styrene-acrylic latex, polyvinyl alcohol, ethylene-vinyl acetate copolymer and polyurethane.
Further, the wetting agent is one or more of fluoroalkyl methoxy ether alcohol, fluoroalkyl ethoxy ether alcohol, alkylphenol ethoxylate, fatty alcohol polyoxyethylene ether and fatty acid polyoxyethylene ether.
On the other hand, the invention provides a preparation method of the water-based ceramic/PVDF mixed coating membrane, which comprises the following specific processes:
A) coating the prepared water-based ceramic/PVDF mixed coating slurry on a polyethylene diaphragm to obtain a wet film;
B) and drying the obtained wet film to obtain the water-based ceramic/PVDF mixed coating diaphragm.
Further, the thickness of the wet film in the step A) is 3-50 μm.
Further, the drying conditions in step B) are as follows: the temperature is 30-50 ℃, the relative humidity is 0.1-10%, and the drying time is 10-30 min.
In another aspect, the present invention provides an aqueous ceramic/PVDF hybrid coating slurry prepared by the method of the present invention.
In another aspect, the invention provides a water-based ceramic/PVDF mixed coating membrane prepared by the method of the invention.
In another aspect, the invention provides a lithium ion battery comprising a positive electrode material and a negative electrode material, wherein the water-based ceramic/PVDF mixed coating membrane is arranged between the positive electrode material and the negative electrode material.
The invention has the beneficial effects that:
the invention provides a water-based ceramic/PVDF mixed coating slurry, a preparation method and application thereof, and the water-based ceramic/PVDF mixed coating slurry has the following advantages:
when the prepared water-based ceramic/PVDF mixed coating slurry is used, the advantages are as follows:
1) perfluoroalkyl dispersing agents are adopted as the emulsifying agents, and in the emulsion polymerization reaction process of PVDF, the hydrophobic chain segments (such as: perfluoroalkyl) can be embedded in the PVDF emulsion particles, a hydrophilic segment on the surface of the PVDF particles (e.g.: acrylic acid chain segments, caprylic acid amine segments, carboxylic acid amine segments and sodium sulfonate segments) have good affinity with water, the hydrophilicity of the PVDF particles is remarkably improved, and the crystallinity of the PVDF particles is remarkably reduced. Compared with PVDF particles prepared by a conventional method, the PVDF emulsion prepared by the process disclosed by the invention can be uniformly dispersed in an aqueous solution without agglomeration and sedimentation, the hydrophilic chain segment is favorable for wettability with an electrolyte in the subsequent process, and the PVDF with low crystallinity is more favorable for improving the liquid absorption rate and the ionic conductivity of the diaphragm.
2) The ceramic material and the first dispersing agent are uniformly dispersed in water, wherein the dispersing agent can break up and prevent the ceramic material from agglomerating, so that the agglomeration of the ceramic material is avoided; adding a thickening agent with more hydrophilic groups and an adhesive to further disperse uniformly; uniformly dispersing the PVDF emulsion and the wetting agent, wherein the wetting agent can increase the interfacial tension of the ceramic material, improve the hydrophilicity of the ceramic material and the wettability between the PVDF emulsion and the wetting agent, and the adhesive can ensure the adhesive capacity between the coating and the diaphragm substrate;
3) the ceramic particles and the PVDF particles in the prepared water-based ceramic/PVDF mixed coating slurry can be uniformly dispersed in the slurry, so that the dispersion stability is good, and the uniformity of the slurry is good.
The water-based ceramic/PVDF mixed coating membrane prepared by the invention has the following advantages:
the prepared slurry has good uniformity, after the slurry is coated on the membrane surface of the diaphragm substrate, the membrane surface is flat, particles are uniformly dispersed, and the agglomeration phenomenon is avoided, and the uniform coating is favorable for improving the uniformity of local current in the charging and discharging processes of the lithium ion battery, so that the cycle life of the battery is remarkably prolonged.
The coating diaphragm is dried under the condition of low temperature and low humidity, so that the phenomenon that the prepared PVDF particles with low melting point melt and block holes in the drying process of the coating diaphragm is avoided, the air permeability of the coating diaphragm can be increased, and the obtained diaphragm has compact surface, uniform thickness and high heat resistance; the prepared coating has strong binding force with the diaphragm, and particularly has heat shrinkage performance, so that the problem of diaphragm powder falling can be effectively inhibited;
the preparation method of the invention has simple process and no pollution to the environment, and is suitable for industrial production.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
FIG. 1 is an SEM image of an aqueous PVDF emulsion prepared by the preferred embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments that can be derived by one of ordinary skill in the art from the embodiments given herein are intended to be within the scope of the present invention.
Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.
Unless otherwise specified, the reagents and materials used in the present invention are commercially available products or products obtained by a known method.
Example 1
Adding 170g of high-purity water, 0.5g of perfluoroalkyl acrylate, 0.5g of perfluoroalkyl carboxylic acid amine, 0.5g of tert-butyl hydroperoxide and 1g of acetone into a nitrogen-filled high-pressure reaction kettle, uniformly mixing, continuously introducing 60g of vinylidene fluoride monomer and 40g of hexafluoropropylene monomer gas into the mixed solution at 60 ℃, controlling the reaction pressure to be 4.0Mpa by adjusting the gas flow, reacting for 8 hours, filtering, washing for 5 times with pure water to obtain concentrated PVDF polymer emulsion, adding deionized water into the concentrated PVDF polymer emulsion to adjust the solid content, and preparing the aqueous PVDF polymer emulsion with the mass fraction of 20%.
Adding 20g of magnesium hydroxide, 0.1g of styrene-maleic anhydride and 0.4g of sodium polyacrylate into 45g of deionized water, stirring for 3 hours, adding 0.2g of hydroxyethyl cellulose and 15g of polyurethane, continuing stirring for 6 hours, and finally adding 20g of aqueous PVDF polymer emulsion and 0.21g of fatty alcohol-polyoxyethylene ether simultaneously and stirring for 9 hours to obtain the aqueous ceramic/PVDF mixed coating slurry.
The aqueous ceramic/PVDF mixed coating slurry was coated on a polyethylene separator to obtain a wet film having a thickness of 10 μm. And drying the coated wet film for 10min at the temperature of 40 ℃ and the humidity of 1 percent to obtain the water-based ceramic/PVDF mixed coating diaphragm.
The decomposition voltage of the diaphragm is 4.9V, the thermal shrinkage after baking for 1h at 150 ℃ is 1.8% (MD direction) and 0.9% (TD direction), the puncture strength is 5.1N, the tensile strength is 210Mpa (MD direction) and 180Mpa (TD direction), the liquid absorption rate is 170%, the film rupture temperature is 170 ℃, and the lithium ion conductivity is 1.58 multiplied by 10-3S/cm, and the transference number of lithium ions was 0.73. And (3) assembling the lithium cobaltate, the lithium sheet, the electrolyte and the water-based ceramic/PVDF mixed coating diaphragm into a button cell, testing the performance of the button cell, and keeping the capacity retention rate of 81.7% after circulating for 300 circles under the charge-discharge rate of 3C.
Example 2
Adding 150g of high-purity water, 0.5g of sodium perfluoroalkyl sulfonate, 0.9g of tert-butyl hydroperoxide and 0.8g of acetone into a high-pressure reaction kettle filled with nitrogen, uniformly mixing, continuously introducing 60g of vinylidene fluoride monomer and 40g of hexafluoropropylene monomer gas into the mixed solution at 80 ℃, controlling the reaction pressure to be 2.0MPa by adjusting the gas flow, reacting for 10 hours, filtering the prepared PVDF emulsion, washing with pure water for 3 times to obtain a concentrated PVDF polymer emulsion, adding deionized water into the concentrated PVDF polymer emulsion to adjust the solid content, and preparing the aqueous PVDF polymer emulsion with the mass fraction of 20%.
Adding 10g of alumina and 0.01g of sodium polyacrylate into 45g of deionized water, stirring for 8 hours, adding 0.25g of sodium carboxymethylcellulose, 0.25g of sodium alginate and 7.5g of butylbenzene latex, continuing stirring for 10 hours, and finally simultaneously adding 40g of aqueous PVDF polymer emulsion, 0.21g of fatty acid polyoxyethylene ether and 0.29g of fluoroalkyl methoxy ether alcohol and stirring for 3 hours to obtain the aqueous ceramic/PVDF mixed coating slurry.
The aqueous ceramic/PVDF mixed coating slurry was coated on a polyethylene separator to obtain a wet film having a thickness of 30 μm. And drying the coated wet film for 15min at the temperature of 50 ℃ and the humidity of 10 percent to obtain the water-based ceramic/PVDF mixed coating diaphragm.
The decomposition voltage of the diaphragm is 4.7V, the thermal shrinkage after baking for 1h at 150 ℃ is 1.5% (MD direction) and 0.7% (TD direction), the puncture strength is 5.3N, the tensile strength is 250Mpa (MD direction) and 192Mpa (TD direction), the liquid absorption rate is 283%, the film breaking temperature is 180 ℃, and the lithium ion conductivity is 1.73 multiplied by 10-3S/cm, the transference number of lithium ions is 0.69. And (3) assembling the lithium cobaltate, the lithium sheet, the electrolyte and the water-based ceramic/PVDF mixed coating diaphragm into a button cell, testing the performance of the button cell, and keeping the capacity retention rate of 83.5% after circulating for 300 circles under the charge-discharge rate of 3C.
Example 3
Adding 200g of high-purity water, 0.8g of perfluoroalkyl acrylate, 0.3g of tert-butyl hydroperoxide and 1.7g of acetone into a high-pressure reaction kettle filled with nitrogen, uniformly mixing, continuously introducing 60g of vinylidene fluoride monomer and 40g of hexafluoropropylene monomer gas into the mixed solution at 100 ℃, controlling the reaction pressure to be 1.5Mpa by adjusting the gas flow, reacting for 15 hours, filtering the prepared PVDF emulsion, washing with pure water for 4 times to obtain a concentrated PVDF polymer emulsion, adding deionized water into the concentrated PVDF polymer emulsion to adjust the solid content, and preparing the aqueous PVDF polymer emulsion with the mass fraction of 20%.
Adding 10g of titanium dioxide, 20g of boehmite and 2.0g of polyethylene glycol into 45g of deionized water, stirring for 3 hours, adding 0.5g of methylhydroxyethyl cellulose, 5.0g of styrene-acrylic emulsion and 6.0g of polyacrylate emulsion, continuing stirring for 6 hours, and finally simultaneously adding 10g of aqueous PVDF polymer emulsion and 0.05g of fluoroalkyl ethoxy ether alcohol and stirring for 9 hours to obtain PVDF/alumina blended slurry.
The aqueous ceramic/PVDF mixed coating slurry was coated on a polyethylene separator to obtain a wet film having a thickness of 50 μm. And drying the coated wet film for 30min at the temperature of 30 ℃ and the humidity of 0.1 percent to obtain the water-based ceramic/PVDF mixed coating diaphragm.
The membrane has a decomposition voltage of 5.1V at 150After baking for 1h, the thermal shrinkage was 1.2% (MD) and 0.6% (TD) respectively, the puncture strength was 5.6N, the tensile strength was 351MPa (MD) and 215MPa (TD) respectively, the liquid absorption rate was 337%, the film rupture temperature was 210 ℃, and the lithium ion conductivity was 2.75X 10-3S/cm, the transference number of lithium ions was 0.77. And (3) assembling the lithium cobaltate, the lithium sheet, the electrolyte and the water-based ceramic/PVDF mixed coating diaphragm into a button cell, testing the performance of the button cell, and keeping the capacity retention rate of 86.9% after circulating for 300 circles under the charge-discharge rate of 3C.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (5)
1. A preparation method of water-based ceramic/PVDF mixed coating slurry is characterized by comprising the following specific steps:
stirring and mixing high-purity water, perfluoroalkyl dispersing agents, tert-butyl hydroperoxide and acetone uniformly in a nitrogen atmosphere, wherein the rotating speed is 70rpm/min, the stirring time is 1-5 h, the heating temperature is 60-100 ℃, continuously introducing vinylidene fluoride monomer and hexafluoropropylene monomer gases, adjusting the gas flow rate, controlling the reaction pressure to be 1.5-4.0 Mpa, adjusting the reaction time to be 8-15 h, filtering after the reaction is finished, washing with deionized water for 3-5 times, preparing 20 mass percent aqueous PVDF polymer emulsion with deionized water, and adjusting the solid content to obtain the aqueous PVDF emulsion;
in the step 1), the ratio of the high-purity water, the perfluoroalkyl dispersant, the tert-butyl hydroperoxide, the acetone, the vinylidene fluoride monomer and the hexafluoropropylene monomer is 150-200: 0.5-1: 0.3-0.9: 0.8-1.7: 60:40 in parts by weight;
dispersing a ceramic material and a first dispersing agent in deionized water, stirring for 0.5-8 h, adding a thickening agent and an adhesive for dispersion, stirring for 2-10 h, adding the aqueous PVDF emulsion and the wetting agent obtained in the step 1) while stirring for 3-9 h, and uniformly mixing to obtain aqueous ceramic/PVDF mixed coating slurry;
in the step 2), the mixture ratio of the ceramic material, the first dispersing agent, the deionized water, the thickening agent, the adhesive, the aqueous PVDF emulsion obtained in the step 1) and the wetting agent is 10-30: 0.01-2: 45: 0.1-0.5: 7-15: 10-40: 0.05-0.5 in parts by weight;
the perfluoroalkyl dispersant is perfluoroalkyl ethyl acrylate;
the ceramic material is boehmite and titanium dioxide;
the first dispersant is polyethylene glycol;
the thickening agent is methyl hydroxyethyl cellulose;
the adhesive is styrene-acrylic latex;
the wetting agent is fluoroalkyl ethoxy ether alcohol.
2. A preparation method of a water-based ceramic/PVDF mixed coating membrane is characterized by comprising the following specific steps:
coating the water-based ceramic/PVDF mixed coating slurry prepared by the method of claim 1 on a polyethylene diaphragm to obtain a wet film;
and drying the obtained wet film to obtain the water-based ceramic/PVDF mixed coating diaphragm.
3. The preparation method of the water-based ceramic/PVDF mixed coating membrane as claimed in claim 2, wherein the thickness of the wet membrane is 3-50 μm;
the drying conditions were as follows: the temperature is 30-50 ℃, the relative humidity is 0.1-10%, and the drying time is 10-30 min.
4. An aqueous ceramic/PVDF mixed coated separator membrane prepared by the method of any of claims 2-3.
5. A lithium ion battery comprising a positive electrode material and a negative electrode material, wherein the aqueous ceramic/PVDF mixed coating membrane according to claim 4 is arranged between the positive electrode material and the negative electrode material.
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| CN110112348B (en) * | 2019-03-19 | 2021-09-28 | 上海恩捷新材料科技有限公司 | Battery coating film slurry, battery diaphragm, secondary battery and preparation method thereof |
| CN110660949A (en) * | 2019-10-08 | 2020-01-07 | 宁波中科达新材料有限公司 | Preparation method of inorganic and organic composite coating diaphragm |
| CN110911620B (en) * | 2019-10-19 | 2022-04-29 | 东莞东阳光科研发有限公司 | Spotted coating diaphragm slurry, composite diaphragm and preparation method thereof |
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| CN111129405A (en) * | 2019-12-30 | 2020-05-08 | 河北金力新能源科技股份有限公司 | Mixed coating diaphragm slurry and preparation method thereof, mixed coating diaphragm and lithium battery |
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| CN113363670A (en) * | 2021-04-30 | 2021-09-07 | 万向一二三股份公司 | Diaphragm and lithium ion battery comprising same |
| CN114221088A (en) * | 2021-11-30 | 2022-03-22 | 中材锂膜有限公司 | High-adhesion-strength PVDF (polyvinylidene fluoride) coated diaphragm and preparation method thereof |
| CN115000622B (en) * | 2022-07-21 | 2024-04-26 | 浙江人行道化工有限公司 | PVDF coated diaphragm and preparation method thereof |
| CN115101894B (en) * | 2022-08-18 | 2024-10-11 | 宁德卓高新材料科技有限公司 | PVDF (polyvinylidene fluoride) coated diaphragm and preparation method and application thereof |
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| CN103187549B (en) * | 2011-12-28 | 2015-04-22 | 山东东岳高分子材料有限公司 | Diaphragm for lithium ion battery and preparation method thereof |
| KR20150010159A (en) * | 2013-07-18 | 2015-01-28 | 삼성에스디아이 주식회사 | Rechargeable lithium battery and method of preparing the same |
| CN104143615B (en) * | 2013-08-26 | 2016-08-03 | 河南师范大学 | A kind of lithium ion battery composite separation membrane and preparation method thereof |
| CN105085753B (en) * | 2014-05-07 | 2017-05-10 | 浙江蓝天环保高科技股份有限公司 | Preparation method for polyvinylidene difluoride resin with high thermal stability and copolymer of polyvinylidene difluoride resin |
| CN104332578A (en) * | 2014-11-20 | 2015-02-04 | 深圳市星源材质科技股份有限公司 | Adhesive composite diaphragm and manufacturing method thereof |
| CN105061659A (en) * | 2015-07-31 | 2015-11-18 | 深圳诚立胜新材料科技有限公司 | Fluorine-containing material preparation method, and application of fluorine-containing material prepared through using method |
| CN106336476B (en) * | 2016-08-25 | 2019-12-10 | 浙江孚诺林化工新材料有限公司 | preparation method of vinylidene fluoride copolymer with high elongation at break |
| CN106684296A (en) * | 2016-08-26 | 2017-05-17 | 宁德卓高新材料科技有限公司 | PVDF (polyvinylidene fluoride) mixed coating diaphragm with good safety and preparation method thereof |
| CN106784534B (en) * | 2016-08-29 | 2019-09-13 | 东莞市卓高电子科技有限公司 | The preparation method of PVDF copolymer ceramic coating membrane |
| CN106654123B (en) * | 2017-01-20 | 2020-01-24 | 东莞市卓高电子科技有限公司 | Preparation method of PVDF (polyvinylidene fluoride) or PVDF (polyvinylidene fluoride) copolymer coating diaphragm |
| CN107093694B (en) * | 2017-05-17 | 2019-12-31 | 河北金力新能源科技股份有限公司 | Water-based PVDF (polyvinylidene fluoride) coated lithium ion battery diaphragm and preparation method thereof |
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