CN113363672A - Spraying diaphragm for lithium ion battery and preparation method thereof - Google Patents
Spraying diaphragm for lithium ion battery and preparation method thereof Download PDFInfo
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- CN113363672A CN113363672A CN202010149581.0A CN202010149581A CN113363672A CN 113363672 A CN113363672 A CN 113363672A CN 202010149581 A CN202010149581 A CN 202010149581A CN 113363672 A CN113363672 A CN 113363672A
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- 238000005507 spraying Methods 0.000 title claims abstract description 66
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- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 33
- 238000002360 preparation method Methods 0.000 title claims abstract description 9
- 238000000576 coating method Methods 0.000 claims abstract description 71
- 239000011248 coating agent Substances 0.000 claims abstract description 69
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- 238000000034 method Methods 0.000 claims abstract description 8
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- 238000003756 stirring Methods 0.000 claims description 21
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- 238000002156 mixing Methods 0.000 claims description 13
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- 229910001593 boehmite Inorganic materials 0.000 claims description 11
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 claims description 11
- 239000000203 mixture Substances 0.000 claims description 9
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- 230000035699 permeability Effects 0.000 claims description 6
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- 239000007921 spray Substances 0.000 claims description 5
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- 239000004642 Polyimide Substances 0.000 claims description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 4
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 4
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 4
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 4
- 239000007864 aqueous solution Substances 0.000 claims description 4
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- IXPNQXFRVYWDDI-UHFFFAOYSA-N 1-methyl-2,4-dioxo-1,3-diazinane-5-carboximidamide Chemical compound CN1CC(C(N)=N)C(=O)NC1=O IXPNQXFRVYWDDI-UHFFFAOYSA-N 0.000 claims description 3
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- 229920003169 water-soluble polymer Polymers 0.000 claims description 3
- 238000003618 dip coating Methods 0.000 claims description 2
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 claims description 2
- 239000000347 magnesium hydroxide Substances 0.000 claims description 2
- 229910001862 magnesium hydroxide Inorganic materials 0.000 claims description 2
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- 238000005303 weighing Methods 0.000 description 3
- DPXJVFZANSGRMM-UHFFFAOYSA-N acetic acid;2,3,4,5,6-pentahydroxyhexanal;sodium Chemical compound [Na].CC(O)=O.OCC(O)C(O)C(O)C(O)C=O DPXJVFZANSGRMM-UHFFFAOYSA-N 0.000 description 2
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Images
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
-
- 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
-
- 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
- H01M50/451—Separators, membranes or diaphragms characterised by the material having a layered structure comprising layers of only organic material and layers containing inorganic material
-
- 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
- H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
- H01M50/491—Porosity
-
- 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
Abstract
The invention discloses a spraying diaphragm for a lithium ion battery, which comprises a porous base film, an inorganic heat-resistant coating coated on one side of the base film and organic particle point-shaped coatings sprayed on the side of the inorganic heat-resistant coating and the other side of the base film. The total thickness of the spraying diaphragm is 6-50 μm, wherein the organic particle dot-shaped coating thickness is 0.5-10 μm, the coverage area of the dot-shaped coating is 10% -60% of the surface area of the base material, the shape of the spraying point is approximately circular, and the area of a single point is 314 μm2‑7mm2The organic particles account for 40-100% of each spraying point, the organic particle point-like coating has adhesive property, the diaphragm and the electrode can be adhered together by a hot pressing process in the preparation process of the battery core,the hardness of the battery core is improved, the lithium ion channel is shortened, and the safety performance of the battery is improved.
Description
Technical Field
The invention belongs to the technical field of lithium ion batteries, and particularly relates to a novel spraying diaphragm for a lithium ion battery and a preparation method thereof.
Background
Currently, ceramic-coated separators have been widely used in power lithium ion batteries because of their good heat resistance and electrolyte wettability. However, in the manufacturing process of the battery, the problems that the pole piece is not tightly attached to the diaphragm, the battery core is soft and the like still exist. In order to solve the problem, a newly developed lithium ion battery diaphragm is added with a functional coating with adhesive property on the basis of a ceramic coating film, and the functional coating plays a role in adhering a positive electrode, a negative electrode and the diaphragm so as to improve the hardness of a battery core and further improve the safety performance of the battery. However, the existing functional coating has high coverage rate, which often causes the increase of the internal resistance of the battery and the water jump at the end of the battery cycle. Therefore, it is necessary to reasonably control the coverage area of the functional coating so that the separator has certain adhesive property and the performance of the battery is not affected.
Disclosure of Invention
The invention aims to overcome the technical problems in the prior art, and provides a diaphragm which has certain adhesive property, does not influence the internal resistance and the cycle performance of a lithium ion battery, and improves the liquid absorption and the liquid retention of electrolyte of the diaphragm.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a spray coating diaphragm for lithium ion battery comprises a porous base film, an inorganic heat-resistant coating coated on one side of the base film and an organic particle dot-shaped coating sprayed on the other side of the base film, wherein the total thickness of the spray coating diaphragm is controlled within the range of 6-50 mu m.
The porous base membrane material is selected from one or more of Polyethylene (PE), polypropylene (PP), Polyimide (PI), polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), Polyamide (PA) and polyethylene terephthalate (PET), the thickness of the base membrane is 3-25 mu m, the porosity is 20-80%, and the air permeability is 50-800 s/100 cc.
The thickness of the inorganic heat-resistant coating is 1-10 mu m, and the inorganic heat-resistant coating mainly comprises inorganic filler, thickener and adhesive resin.
The inorganic filler is one or more of alumina, boehmite, silica, titanium dioxide, zirconia, magnesia and magnesium hydroxide, and the specific surface area is 2-10 m2/g。
The thickness of the organic particle dotted coating is 0.5-10 mu m, the coverage area of the dotted coating is 10% -60% of the surface area of the base material, the shape of the spraying points is approximately circular, and the area of a single spraying point is 314 mu m2-7 mm2The organic particles in a single spraying point account for 40-100%, and the bonding strength with the pole piece is more than 0.1N/m.
The slurry used for the organic particle point coating is composed of the following raw materials: 65-90% of aqueous solution by mass, 5-30% of organic polymer by mass, 0.01-10% of thickening agent by mass, 0.1-5% of binding agent by mass, 0.001-1% of wetting agent by mass, 5-30% of solid content of slurry and 5-100 mpa · s of viscosity.
The organic particles comprise one or a mixture of more than two of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyvinylidene fluoride-trifluoroethylene copolymer, polyvinylidene fluoride-chlorotrifluoroethylene copolymer, tetrafluoroethylene-vinylidene fluoride copolymer and polymethyl methacrylate.
The thickening agent comprises one or more of carboxymethyl cellulose, hydroxyethyl cellulose, carboxyethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, polyallyl alcohol and sodium alginate.
The binder resin is a water-soluble polymer and comprises one or more of polyacrylic acid, polyacrylamide, polymethacrylic acid, polymethyl methacrylate and polyvinyl alcohol.
A spraying diaphragm for a lithium ion battery and a preparation method thereof are prepared according to the following method:
(1) preparing inorganic heat-resistant layer slurry, then coating the inorganic heat-resistant layer slurry on one side of a base film, and drying to obtain an inorganic heat-resistant layer;
(2) preparing organic particle point coating slurry:
A. mixing the organic polymer powder and the thickening agent, stirring and kneading the mixture into a uniform creamy mixture;
B. adding the aqueous solution into the A under the stirring action to adjust the solid content of the slurry and continuously stirring the slurry uniformly to form a uniform solution;
C. continuously adding the binder into the B, and uniformly mixing to obtain a finished product slurry;
(3) coating the slurry prepared in the step (2) on the other side of the base film and the side of the inorganic coating layer in a rotary spraying mode to obtain an organic particle point coating;
(4) and drying in an oven to obtain the spray coating diaphragm for the lithium ion battery.
The coating mode in the step (1) adopts one of gravure roll coating, wire bar coating, slit coating and dip coating.
The kneading time of the organic polymer and the thickening agent in the step (2) is more than or equal to 20 min.
The rotating speed of the rotary spraying is 3000-15000 r/min, and the speed of the rotary spraying is 10-150 m/min.
The drying temperature in the step (4) is less than or equal to 90 ℃.
The invention provides a preparation method of a spraying diaphragm for a lithium ion battery, which comprises the steps of coating prepared inorganic slurry on one side of a porous base film to obtain an inorganic heat-resistant layer, so that the heat resistance of the diaphragm is improved, and the safety performance of the battery is greatly improved; and then coating the prepared organic slurry on two sides of the inorganic coating film in a rotary spraying mode to ensure that two sides of the diaphragm have adhesive property. The preparation method is simple, has low requirements on equipment, is easy to control conditions, and is suitable for industrial production.
Drawings
Fig. 1 is a schematic structural diagram of a spray coating separator for a lithium ion battery according to the present invention.
Fig. 2 is a schematic distribution diagram of organic particle dots of a dot-shaped coating sprayed.
FIG. 3 is a scanning electron micrograph of the sprayed separator in example 1.
1-porous base film, 2-inorganic heat-resistant coating and 3-organic particle dotted coating.
Detailed Description
The present invention is described in detail below by way of specific examples, which are provided only for illustrating the present invention and are not intended to limit the scope of the present invention.
Example 1
a. Preparing ceramic slurry: the specific surface area is 5 m2Adding alumina powder as an inorganic filler per gram into a hydrosolvent, uniformly stirring, adding a thickening agent, uniformly stirring to adjust the viscosity of the slurry, grinding, adding a certain amount of a binder and a wetting agent, and uniformly mixing to obtain the finished inorganic coating slurry.
b. Coating of inorganic slurry: and (b) selecting a wet-process synchronous double-drawing polyethylene diaphragm with the thickness of 9 mu m, coating the ceramic slurry prepared in the step (a) on one side of the base film in a micro gravure roll type coating mode at the coating speed of 100 m/min, and drying to obtain the ceramic coating diaphragm, wherein the porosity is 40% and the air permeability is 160 s/100cc, and the thickness of the ceramic coating diaphragm is 3 mu m.
c. Preparing PVDF spraying coating slurry: weighing a certain amount of polyvinylidene fluoride-hexafluoropropylene copolymer powder and a thickening agent sodium carboxymethyl cellulose, mixing, stirring and kneading for 60 min to form a uniform creamy mixture, and then adding ultrapure water under the stirring action to adjust the solid content of the slurry and form a uniform solution; and finally, adding the adhesive into the uniform solution, and uniformly stirring and mixing to obtain the PVDF slurry.
d. Coating of PVDF slurry: and (c) simultaneously coating the PVDF slurry prepared in the step (c) on two sides of the ceramic coating film in a high-speed rotary spraying mode, wherein the coating speed is 30 m/min, the rotating speed of a rotary spray head is 10000 rpm/min, and drying to obtain the spraying diaphragm. The thickness of the single-layer PVDF spraying coating is 3 mu m, the area of a PVDF spraying point accounts for 30% of the area of the base film, and the PVDF coverage area in the single PVDF spraying point accounts for about 50% of the area of the spraying point. Scanning electron microscopy of the PVDF spray coating is shown in fig. 3.
The thickness of the spraying diaphragm for the lithium ion battery is 17.5 mu m, the thickness of the ceramic coating is 3 mu m, and the thickness of the double-sided PVDF coating is 5.5 mu m. Carrying out hot pressing treatment on the sprayed diaphragm and the positive pole piece by using a flat hot press at 85 ℃ under the condition of 1 Mpa for 5 min, and testing the bonding strength by using a tensile machine, wherein the test result is 0.9N/m2。
Example 2
a. Preparation of boehmite slurry: adding boehmite powder into a hydrosolvent, stirring and dispersing, then adding a thickening agent, uniformly stirring to adjust the viscosity of the slurry, finally adding a certain amount of a binder and a wetting agent, and uniformly mixing to obtain the finished boehmite slurry.
b. Coating of boehmite slurry: and (3) selecting a wet-process asynchronous-stretching polyethylene membrane with the thickness of 12 microns, wherein the porosity is 42%, coating the boehmite slurry prepared in the step (a) on one side of the base membrane in a narrow-slit coating mode at the coating speed of 60 m/min, and drying to obtain the boehmite coated membrane, wherein the thickness of the boehmite coating is 4 microns.
c. Preparing PVDF spraying coating slurry: weighing a certain amount of polyvinylidene fluoride powder and hydroxyethyl cellulose, mixing, stirring and kneading for 30 min to form a uniform creamy mixture, and then adding ultrapure water under the stirring action to adjust the solid content of the slurry and form a uniform solution; and finally, adding the adhesive into the uniform solution, and uniformly stirring and mixing to obtain the PVDF slurry.
d. Coating of PVDF slurry: and (c) simultaneously coating the PVDF slurry prepared in the step (c) on two sides of the boehmite coating film in a high-speed rotary spraying mode, wherein the coating speed is 30 m/min, the rotating speed of a rotary spray head is 8000 rpm/min, and drying to obtain the spraying diaphragm. The thickness of the single-layer PVDF spraying coating is 3 mu m, and the area of a single-layer PVDF spraying point accounts for 25 percent of the area of the base membrane.
The thickness of the spraying diaphragm for the lithium ion battery is 22 mu m, the thickness of the boehmite coating is 4 mu m, and the thickness of the double-sided PVDF coating is 6 mu m. Hot pressing the sprayed diaphragm and the positive pole piece by a flat hot press at 85 ℃ under 1 Mpa for 5 min, and then carrying out hot pressing treatment on the sprayed diaphragm and the positive pole pieceThe bonding strength of the adhesive is tested by a tensile machine, and the test result is 1.2N/m2。
Example 3
a. Preparing ceramic slurry: the specific surface area is 5 m2Adding alumina powder as an inorganic filler per gram into a hydrosolvent, uniformly stirring, adding a thickening agent, uniformly stirring to adjust the viscosity of the slurry, grinding, adding a certain amount of a binder and a wetting agent, and uniformly mixing to obtain the finished inorganic coating slurry.
b. Coating of inorganic slurry: and (b) selecting a wet-process synchronous double-drawing polyethylene diaphragm with the thickness of 9 mu m, coating the ceramic slurry prepared in the step (a) on one side of the base film in a micro gravure roll type coating mode at the coating speed of 100 m/min, and drying to obtain the ceramic coating diaphragm, wherein the porosity is 40% and the air permeability is 160 s/100cc, and the thickness of the ceramic coating diaphragm is 3 mu m.
c. Preparing polymethyl methacrylate spraying coating slurry: weighing a certain amount of polymethyl methacrylate and thickener sodium carboxymethylcellulose, mixing, stirring for 20 min, and then adding ultrapure water under the stirring action to adjust the solid content of the slurry and form a uniform solution; finally, adding the adhesive and the wetting agent into the uniform solution, and uniformly stirring and mixing to obtain the polymethyl methacrylate slurry.
d. Coating of polymethyl methacrylate slurry: and c, spraying the polymethyl methacrylate slurry prepared in the step c on two sides of the ceramic coating film simultaneously in a high-speed rotary spraying mode, wherein the coating speed is 40 m/min, the rotating speed of a rotary spray head is 8000 rpm/min, and drying is carried out at 65 ℃ to obtain the spraying diaphragm. The thickness of the single-layer polymethyl methacrylate spraying coating is 2 mu m, the area of the spraying point accounts for 30 percent of the area of the substrate, and the coverage area of the polymethyl methacrylate particles in the single spraying point accounts for about 100 percent of the area of the spraying point.
The thickness of the spraying diaphragm for the lithium ion battery is 15.9 mu m, the thickness of the ceramic coating is 2.9 mu m, and the thickness of the double-sided PVDF coating is 4.0 mu m. Carrying out hot pressing treatment on the sprayed diaphragm and the positive pole piece by using a flat hot press at 85 ℃ under the condition of 1 Mpa for 5 min, and testing the bonding strength by using a tensile machine, wherein the test result is 2.8N/m2。
Comparative example 4
The ceramic slurry in the example 1 is used for preparing a 9+3 ceramic coating film, then the PVDF slurry in the example 1 is respectively coated on two sides of the 9+3 ceramic film in a micro gravure roller coating mode, the following table shows the comparison between the two products and the finished product in the example 1, the PVDF coverage rate of the micro gravure roller coated finished product is high, the air permeability is high, and the internal resistance of the battery is larger, while the coverage rate of the diaphragm prepared by spraying is low, the air permeability is small, and the internal resistance of the battery is basically similar to the internal resistance of the ceramic film battery.
Claims (15)
1. A spraying diaphragm for a lithium ion battery is characterized by comprising a porous base film, an inorganic heat-resistant coating coated on one side of the base film and organic particle point-shaped coatings sprayed on the side of the inorganic heat-resistant coating and the other side of the base film; the total thickness of the spraying diaphragm is 6-50 μm, wherein the thickness of the organic particle dot-shaped coating is 0.5-10 μm, the coverage area of the dot-shaped coating is 10-60% of the surface area of the base material, the shape of the spraying points is approximately circular, and the area of a single spraying point is 314 μm2-7 mm2The proportion of the organic particles in a single spraying point is 40-100%, and the bonding strength with the pole piece is more than 0.1N/m.
2. The spray coating separator for lithium ion battery according to claim 1, wherein the material of the porous base film is selected from one or more of Polyethylene (PE), polypropylene (PP), Polyimide (PI), polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), Polyamide (PA), polyethylene terephthalate (PET), the thickness of the base film is 3-25 μm, the porosity is 20% -80%, and the air permeability is 50-800 s/100 cc.
3. The spray-coated separator for lithium ion batteries according to claim 1, wherein the thickness of the inorganic heat-resistant coating layer is 1 to 10 μm, and mainly comprises an inorganic filler, a thickener and a binder resin.
4. The spray coating separator for lithium ion batteries according to claim 3, wherein the inorganic filler is any one or a mixture of two or more of alumina, boehmite, silica, titania, zirconia, magnesia and magnesium hydroxide, and has a specific surface area of 2 to 10 m2/g。
5. The spray coating membrane for the lithium ion battery as claimed in claim 3, wherein the thickener is any one or more of carboxymethyl cellulose, hydroxyethyl cellulose, carboxyethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, polypropylene alcohol and sodium alginate.
6. The spray coating separator for the lithium ion battery according to claim 3, wherein the binder resin is a water-soluble polymer comprising one or more of polyacrylic acid, polyacrylamide, polymethacrylic acid, polymethyl methacrylate and polyvinyl alcohol.
7. The spray coating separator for the lithium ion battery according to claim 1, wherein the slurry for the dot coating of the organic particles is composed of the following raw materials: 65-90% of aqueous solution by mass, 5-30% of organic polymer by mass, 0.01-10% of thickening agent by mass, 0.1-5% of binding agent by mass, 0.001-1% of wetting agent by mass, 5-30% of solid content of slurry and 5-100 mpa · s of viscosity.
8. The spray coating separator for lithium ion batteries according to claim 7, wherein the organic particles comprise any one or a mixture of two or more of polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), polyvinylidene fluoride-trifluoroethylene copolymer (PVDF-TrFE), polyvinylidene fluoride-chlorotrifluoroethylene copolymer (PVDF-CTFE), tetrafluoroethylene and difluoroethylene copolymer, and polymethyl methacrylate.
9. The spray coating membrane for the lithium ion battery as claimed in claim 7, wherein the thickener comprises any one or more of carboxymethyl cellulose, hydroxyethyl cellulose, carboxyethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, polypropylene alcohol and sodium alginate.
10. The spray coating separator for lithium ion batteries according to claim 7, wherein the binder resin is a water-soluble polymer comprising one or more of polyacrylic acid, polyacrylamide, polymethacrylic acid, polymethylmethacrylate and polyvinyl alcohol.
11. A process for preparing a spray-coated separator for lithium ion batteries according to claim 1,
(1) preparing inorganic heat-resistant layer slurry, then coating the inorganic heat-resistant layer slurry on one side of a base film, and drying to obtain an inorganic heat-resistant layer;
(2) preparing organic particle point coating slurry:
A. mixing the organic polymer and the thickening agent, stirring and kneading the mixture into a uniform creamy mixture;
B. adding the aqueous solution into the A under the stirring action to adjust the solid content of the slurry and continuously stirring the slurry uniformly to form a uniform solution;
C. adding a binder and a wetting agent into the B, and uniformly mixing to obtain a finished product slurry;
(3) coating the slurry in the step (2) on the other side of the base film and the side of the inorganic coating layer in a rotary spraying mode;
(4) and drying in an oven to obtain the lithium ion battery spraying diaphragm.
12. The method for preparing a spray coating separator for a lithium ion battery according to claim 11, wherein the coating manner in the step (1) is one of gravure roll coating, wire bar coating, slit coating and dip coating.
13. The preparation method of the spray coating diaphragm for the lithium ion battery according to claim 11, wherein the kneading time of the organic polymer and the thickener is not less than 20 min.
14. The method for preparing a spraying diaphragm for a lithium ion battery as claimed in claim 11, wherein the spraying speed is 10-150 m/min, and the rotational speed of the rotary spraying is 3000-15000 r/min.
15. The method for preparing the spray coating diaphragm for the lithium ion battery according to claim 11, wherein the drying temperature is less than or equal to 90 ℃.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010149581.0A CN113363672A (en) | 2020-03-06 | 2020-03-06 | Spraying diaphragm for lithium ion battery and preparation method thereof |
| PCT/CN2020/094693 WO2021174709A1 (en) | 2020-03-06 | 2020-06-05 | Spray separator for lithium ion battery and preparation method therefor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010149581.0A CN113363672A (en) | 2020-03-06 | 2020-03-06 | Spraying diaphragm for lithium ion battery and preparation method thereof |
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| CN113363672A true CN113363672A (en) | 2021-09-07 |
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| CN202010149581.0A Pending CN113363672A (en) | 2020-03-06 | 2020-03-06 | Spraying diaphragm for lithium ion battery and preparation method thereof |
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| WO (1) | WO2021174709A1 (en) |
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