Spray adhesive for battery separator and use thereof, battery separator spray slurry and battery separator

Abstract

The present invention relates to the technical field of battery adhesives and to a spray adhesive for a battery separator and a use thereof, a battery separator spray slurry, and a battery separator. The technical problem solved by the present invention is to provide a spray adhesive for a battery separator, wherein the spray adhesive is not prone to powder shedding and has good adhesion to an electrode sheet. The spray adhesive comprises a graft polymer. The graft polymer has an acrylonitrile polymer as a backbone and is grafted with polymeric latex particles, and the weight percentage of the polymeric latex particles in the graft polymer is 65-85%. By spraying the spray adhesive for a battery separator according to the present invention onto a battery separator, the phenomenon that existing acrylonitrile multipolymers are prone to powder shedding can be ameliorated, the adhesion strength to a substrate and an electrode sheet can be improved while a better hollowed-out structure can be maintained, and the sprayed separator exhibits good cold-press adhesion to positive and negative electrodes of a battery. The preparation method for the spray adhesive for a battery separator according to the present invention is simple, and uses water as a solvent for preparation, and the preparation method is green and environmentally friendly, has a low cost, and can achieve industrial production.

Description

Spray adhesive for battery separator and its application, spray slurry for battery separator and battery separator

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to Chinese patent application CN202410304507X, filed on March 18, 2024, and is incorporated herein by reference in its entirety for all other purposes. Technical Field

[0003] The invention relates to a spray adhesive for a battery separator and its application, a battery separator spray slurry and a battery separator, and belongs to the technical field of battery adhesives. Background Art

[0004] Lithium-ion battery separators, a key material in lithium-ion batteries, are typically coated on one or both sides of a microporous base membrane with one or more adhesive functional layers. This layer adheres to the positive and negative electrodes, improves the interface between the separator and the electrodes, and enhances lithium-ion transport. This layer also increases the hardness of the battery cell, thereby enhancing battery safety and cycle life. Commonly used coating materials in the market include polyvinylidene fluoride homopolymer or copolymer (PVDF), polymethyl methacrylate polymer (PMMA), and acrylate polymers. Micro-gravure roller coating and high-speed rotary spraying are common coating processes. High-speed rotary spraying is widely used in lithium-ion power battery systems because it effectively controls coating coverage and reduces battery internal resistance. The slurry used for spraying diaphragms generally includes components such as PVDF / PMMA polymer particles, adhesives, dispersants, wetting agents, etc. After spraying, the slurry agglomerates on the surface of the ceramic layer into a hollow structure: it is surrounded by raised parts, and the interior after the raised parts are enclosed is a hollow part. The adhesive is a crucial link to ensure the dispersion of the polymer, the formation of the hollow structure, and the adhesion to the ceramic layer and the positive and negative electrodes.

[0005] The adhesive is primarily based on an acrylonitrile multipolymer system. This system's polymers have a high polarity, allowing for a well-formed hollow structure. However, due to the significant polarity difference with the base film, powder shedding occurs easily during use. Furthermore, adhesion to the electrode plate needs improvement, resulting in relatively weak adhesion. Therefore, it's necessary to improve the bonding strength between the substrate and the electrode plate while maintaining a good hollow structure. Summary of the Invention

[0006] In view of the above defects, the technical problem solved by the present invention is to provide a spray adhesive for battery separators that is not easy to shed powder and has good bonding performance with the pole pieces.

[0007] The spray adhesive for battery separators of the present invention comprises a grafted polymer, wherein the grafted polymer has an acrylonitrile polymer as the main chain and is grafted with polymer latex particles, and the weight percentage of the polymer latex particles in the grafted polymer is 65-85%, wherein the polymerization monomers of the acrylonitrile polymer include acrylonitrile monomers, acrylic acid monomers and acrylamide monomers; and the polymerization monomers of the polymer latex particles include acrylate monomers.

[0008] In one embodiment of the present invention, the polymerization monomers of the polymer latex particles further include at least one of styrene monomers and acrylonitrile monomers.

[0009] In one embodiment of the present invention, the acrylonitrile monomer includes at least one of acrylonitrile and methacrylonitrile;

[0010] The acrylic monomer includes at least one of acrylic acid, methacrylic acid, allyloxyhydroxypropyl sulfonic acid, vinyl sulfonic acid, 2-acrylamide-2-methylpropane sulfonic acid, propylene sulfonic acid, methpropylene sulfonic acid, itaconic acid, and maleic acid;

[0011] The acrylamide monomer includes at least one of acrylamide, methacrylamide, N-ethylacrylamide, N-hydroxymethylacrylamide, N-hydroxyethylacrylamide, and N-hydroxypropylacrylamide;

[0012] The acrylic acid ester monomers include at least one of methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, butyl acrylate, butyl methacrylate, n-octyl acrylate, isooctyl acrylate, isooctyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, lauryl acrylate, lauryl methacrylate, octadecyl acrylate, octadecyl methacrylate, isobornyl acrylate, and isobornyl methacrylate;

[0013] The styrene monomers include at least one of styrene, p-fluorostyrene, methylstyrene, m-fluorostyrene, o-fluorostyrene, sodium styrene sulfonate, p-methoxystyrene, o-methylstyrene, and p-methylstyrene.

[0014] In one embodiment of the present invention, the weight ratio of acrylonitrile monomer, acrylic acid monomer and acrylamide monomer is 30-60:30-50:8-20. In a specific embodiment, the weight ratio of acrylonitrile monomer, acrylic acid monomer and acrylamide monomer is 50:35:15.

[0015] In some specific embodiments, the weight percentage of the polymer latex particles to the grafted polymer is 75%.

[0016] In some embodiments, the spray adhesive for battery separators further comprises a solvent. In a specific embodiment, the solvent is water.

[0017] In a specific embodiment of the present invention, the spray adhesive for battery separator has a viscosity of 500 to 30,000 mPa·s when measured at 25° C. based on a solid content of 12%.

[0018] The present invention also provides the use of the spray adhesive for battery separators of the present invention in spraying battery separators.

[0019] The battery separator spray adhesive of the present invention can be used for spraying battery separators. The battery separator spray adhesive is mixed with polymer particles such as PVDF or PMMA and water to prepare a slurry, which can be sprayed onto the surface of the battery separator to improve battery performance.

[0020] In a specific embodiment of the present invention, the battery separator is a PP separator or a PE separator.

[0021] In some embodiments, the battery separator can be used in lithium-ion batteries.

[0022] The invention also provides a battery separator spray slurry.

[0023] The battery separator spraying slurry of the present invention comprises polymer particles and the above-mentioned battery separator spraying glue.

[0024] The present invention also provides a battery separator.

[0025] The battery separator of the present invention comprises a base film and a coating on the surface of the base film, and the coating is formed by spraying the battery separator spray slurry of the present invention.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The battery separator spray adhesive of the present invention is sprayed on the battery separator, which can improve the phenomenon that the existing acrylonitrile multi-polymer is easy to fall off powder, and can improve the bonding strength with the substrate and the pole piece while maintaining a good hollow structure. The sprayed separator has good cold pressing bonding performance with the positive and negative electrodes of the battery.

[0028] The preparation method of the spray adhesive for the battery separator of the present invention is simple, uses water as a solvent for preparation, is green and environmentally friendly, has low cost, and can be industrially produced. DETAILED DESCRIPTION

[0029] The spray adhesive for battery separators of the present invention comprises a grafted polymer, wherein the grafted polymer has an acrylonitrile polymer as the main chain and is grafted with polymer latex particles, and the weight percentage of the polymer latex particles in the grafted polymer is 65-85%, wherein the polymerization monomers of the acrylonitrile polymer include acrylonitrile monomers, acrylic acid monomers and acrylamide monomers; and the polymerization monomers of the polymer latex particles include acrylate monomers.

[0030] The battery separator spray adhesive of the present invention is based on an acrylonitrile polymer and is grafted with specific latex particles, which can improve the phenomenon of easy powder loss of existing acrylonitrile multi-polymers and improve the bonding strength with the substrate and the pole piece while maintaining a good hollow structure.

[0031] The graft copolymer of the present invention is a component that plays an adhesive role in the spray adhesive for battery separators. The graft polymer has an acrylonitrile polymer as the main chain and grafted polymer latex particles.

[0032] The acrylonitrile polymer of the present invention can be an acrylonitrile multipolymer commonly used in the art, which is polymerized by acrylonitrile and other monomers containing double bonds. In a specific embodiment of the present invention, the polymerization monomers of the acrylonitrile polymer include acrylonitrile monomers, acrylic acid monomers and acrylamide monomers.

[0033] The acrylonitrile monomer is a substance containing a double bond and a nitrile group, for example, including but not limited to at least one of acrylonitrile and methacrylonitrile.

[0034] Acrylic monomers are substances containing double bonds and carboxyl groups, including but not limited to at least one of acrylic acid, methacrylic acid, allyloxyhydroxypropyl sulfonic acid, vinyl sulfonic acid, 2-acrylamide-2-methylpropanesulfonic acid, propylene sulfonic acid, methpropylene sulfonic acid, itaconic acid, and maleic acid.

[0035] Acrylamide monomers are substances containing double bonds and amide groups, including at least one of acrylamide, methacrylamide, N-ethylacrylamide, N-hydroxymethylacrylamide, N-hydroxyethylacrylamide, and N-hydroxypropylacrylamide.

[0036] The ratio of acrylonitrile monomer, acrylic acid monomer, and acrylamide monomer can be conventional in the art. In one embodiment of the present invention, the weight ratio of acrylonitrile monomer, acrylic acid monomer, and acrylamide monomer is 30-60:30-50:8-20. In a specific embodiment, the weight ratio of acrylonitrile monomer, acrylic acid monomer, and acrylamide monomer is 50:35:15.

[0037] Polymer latex particles are tiny particles formed during the emulsion polymerization process. These particles are formed by free radical polymerization or ionic polymerization of polymerized monomers. The monomers for polymerizing polymer latex particles can be hydrophobic monomers containing double bonds commonly used in the art.

[0038] In one embodiment of the present invention, the polymerization monomers of the polymer latex particles include acrylic acid ester monomers.

[0039] In some embodiments of the present invention, the polymerization monomers of the polymer latex particles further include at least one of styrene monomers and acrylonitrile monomers.

[0040] The acrylic acid ester monomers include at least one of methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, butyl acrylate, butyl methacrylate, n-octyl acrylate, isooctyl acrylate, isooctyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, lauryl acrylate, lauryl methacrylate, octadecyl acrylate, octadecyl methacrylate, isobornyl acrylate, and isobornyl methacrylate.

[0041] The styrene monomers include at least one of styrene, p-fluorostyrene, methylstyrene, m-fluorostyrene, o-fluorostyrene, sodium styrene sulfonate, p-methoxystyrene, o-methylstyrene, and p-methylstyrene.

[0042] The acrylonitrile monomer includes at least one of acrylonitrile and methacrylonitrile.

[0043] In the present invention, the weight percentage of the polymer latex particles in the grafted polymer is key. In one embodiment of the present invention, the weight percentage of the polymer latex particles in the grafted polymer is 65-85%. If the proportion of polymer latex particles is too large, the dispersibility of the grafted polymer on PVDF or PMMA particles will deteriorate. If the proportion of polymer latex particles is too small, the adhesion to the base film is not strong and powdering is likely to occur. In some specific embodiments, the weight percentage of the polymer latex particles in the grafted polymer is 65%, 70%, 75%, 80%, 85%, etc. Preferably, the weight percentage of the polymer latex particles in the grafted polymer is 75%.

[0044] The spray adhesive for battery separators further comprises a solvent. The graft copolymer of the present invention can form a uniform aqueous emulsion in water, so in one embodiment, the solvent is water.

[0045] In some embodiments, the battery separator spray adhesive further comprises an additive, which may be a dispersant, a wetting agent, an antioxidant, a defoaming agent, etc. In one specific embodiment of the present invention, the battery separator spray adhesive has a viscosity of 500 to 30,000 mPa·s when measured at 25° C., based on a solid content of 12%.

[0046] The viscosity of the present invention is measured using a DV2T viscometer (DV2TLV, Brookfield, USA) at a temperature of 25° C., a rotor model No. 63#, and a rotation speed of 12 RPM. The test conditions are: test time = 3 minutes, data collection duration = 2 minutes, and data collection mode: single-point averaging.

[0047] The spray adhesive for the battery separator of the present invention can be prepared by conventional methods.

[0048] In one embodiment of the present invention, the method for preparing the spray adhesive for battery separator comprises the following steps:

[0049] The polymerization monomer of acrylonitrile polymer is mixed with a solvent, and an initiator is added to initiate the reaction; after the reaction for 8 to 16 hours, the polymerization monomer of polymer latex particles and an emulsifier are added, and the reaction is continued until the reaction is completed, and a neutralizer is added for neutralization to obtain a spray adhesive for a secondary battery separator.

[0050] Commonly used emulsifiers in the art are applicable to the present invention. In a specific embodiment of the present invention, the emulsifier is at least one of an ionic emulsifier and a non-ionic emulsifier.

[0051] The ionic emulsifier is at least one of sodium lauryl sulfate, sodium lauryl sulfonate, sodium dodecylbenzene sulfonate and sodium stearate.

[0052] The nonionic emulsifier is at least one of Span 40, Span 80, and OP-10. OP-10 is dodecylphenol polyoxyethylene ether, a commonly used emulsifier available on the market.

[0053] Span, also known as Span, is also a commonly used emulsifier. It can be used in various models, such as Span 80, Span 40, etc.

[0054] In one embodiment of the present invention, the amount of the emulsifier used is 0.2% to 10% by weight of the polymer latex particles. In one embodiment of the present invention, the amount of the emulsifier used is 1% to 5% by weight of the polymer latex particles. In one embodiment of the present invention, the amount of the emulsifier used is 1%, 2%, 3%, 4% or 5% by weight of the polymer latex particles.

[0055] The neutralizing agent can be a substance commonly used in the art that can adjust the pH value. In some embodiments of the present invention, the neutralizing agent is at least one of sodium salt, lithium salt, potassium salt, calcium salt, and organic amine. Organic amines include ammonia water and the like.

[0056] The battery separator spray adhesive of the present invention can be used for spraying battery separators. The battery separator spray adhesive is mixed with polymer particles such as PVDF / PMMA and water to prepare a slurry, which can be sprayed onto the surface of the battery separator to improve battery performance.

[0057] In a specific embodiment of the present invention, the battery separator is a PP separator or a PE separator.

[0058] In some embodiments, the battery separator can be used in lithium-ion batteries.

[0059] The battery separator spraying slurry of the present invention comprises polymer particles and the battery separator spraying glue of the present invention.

[0060] Commonly used polymer particles in the art are applicable to the present invention. In some embodiments, the polymer particles are at least one of PVDF particles, PMMA particles, and acrylate polymer particles.

[0061] The battery separator of the present invention comprises a base film and a coating on the surface of the base film, wherein the coating is formed by spraying the battery separator spraying slurry of the present invention.

[0062] The specific embodiments of the present invention are further described below in conjunction with examples, but the present invention is not limited to the scope of the examples.

[0063] Examples 1-22

[0064] In a 1000 mL four-necked flask, 300 g of distilled water and acrylonitrile polymer monomers were added, and the temperature was raised to the reaction temperature; an initiator was added to initiate the reaction; after a period of reaction (i.e., main chain reaction time), polymer monomers for polymer latex particles and an emulsifier were added; after reacting for 20 hours, sodium hydroxide solution was added to the reaction flask for neutralization and adjustment of the solid content to 12% with deionized water to obtain a spray adhesive for battery separators; wherein, the amount of each monomer and the reaction conditions are shown in Table 1.

[0065] Table 1

[0066] Comparative Example 1

[0067] In a 1000 mL four-necked flask, 300 g of distilled water, 35 g of methacrylic acid, 15 g of methacrylamide, and 50 g of acrylonitrile were added, and the reaction temperature was raised to 70° C.; ammonium persulfate initiator was added to initiate the reaction; after reacting for 20 h, sodium hydroxide solution was added to the reaction flask and neutralized to a pH of 7.47 to obtain a water-based adhesive.

[0068] Comparative Example 2

[0069] In a 1000 mL four-necked flask, 300 g of distilled water, 35 g of methacrylic acid, 15 g of methacrylamide, 50 g of acrylonitrile, 150 g of isooctyl acrylate, 50 g of cyclohexyl methacrylate, 100 g of styrene, 3 g of sodium lauryl sulfate, and 3 g of sodium stearate were added; ammonium persulfate initiator was added to initiate the reaction; after reacting for 20 hours, sodium hydroxide solution was added to the reaction flask and neutralized to a pH of 7.40 to obtain a water-based adhesive.

[0070] Comparative Example 3

[0071] In a 1500mL four-necked flask, 300g of distilled water, 35g of methacrylic acid, 15g of methacrylamide, and 50g of acrylonitrile were added, the reaction temperature was raised to 70°C, and ammonium persulfate initiator was added to initiate the reaction; after reacting for 14h, 366g of isooctyl acrylate, 122g of cyclohexyl methacrylate, 244g of styrene, 7.3g of sodium lauryl sulfate, and 7.3g of sodium stearate were added. After a total reaction time of 20h, sodium hydroxide solution was added to the reaction flask and neutralized to a pH of 7.55 to obtain a water-based adhesive.

[0072] Comparative Example 4

[0073] In a 1000mL four-necked flask, 300g of distilled water, 35g of methacrylic acid, 15g of methacrylamide, and 50g of acrylonitrile were added, the reaction temperature was raised to 70°C, and ammonium persulfate initiator was added to initiate the reaction; after reacting for 14h, 75g of isooctyl acrylate, 25g of cyclohexyl methacrylate, 50g of styrene, 1.5g of sodium lauryl sulfate, and 1.5g of sodium stearate were added, and the reaction temperature was raised to 70°C; after a total reaction time of 20h, sodium hydroxide solution was added to the reaction flask and neutralized to a pH of 7.42 to obtain a water-based adhesive.

[0074] Comparative Example 5

[0075] In a 1000 mL four-necked flask, 150 g of distilled water, 75 g of isooctyl acrylate, 25 g of cyclohexyl methacrylate, 50 g of styrene, 1.5 g of sodium lauryl sulfate, and 1.5 g of sodium stearate were added, and the reaction temperature was raised to 70° C.; ammonium persulfate initiator was added to initiate the reaction; and after reacting for 20 hours, a water-based emulsion adhesive was obtained.

[0076] Comparative Example 6

[0077] The emulsion adhesive prepared in Comparative Example 5 was blended with the aqueous adhesive prepared in Comparative Example 1 at a solid mass ratio of 75%:25% to obtain a blended adhesive.

[0078] The adhesive parameters of the examples and comparative examples are shown in Table 2.

[0079] Table 2

[0080] The properties of the spray adhesive obtained in the above examples and the adhesive obtained in the comparative examples were measured using the following test methods:

[0081] Solid content test: A moisture meter (LHS16-A, accuracy: one thousandth of a gram, Shanghai Tianmei Balance Instrument Co., Ltd.) was used for determination. The heating temperature of the moisture meter was set to 115°C; the heating mode was set to standard; and the end mode was set to automatically stop after 70 seconds.

[0082] pH test: Use a pH meter (Mettler S400K) calibrated with the slope of the alkaline section to measure the pH value of the sample and record the test results.

[0083] Viscosity test: The solids content of the spray adhesive was adjusted to 12% and measured using a DV2T viscometer (DV2TLV, Brookfield, USA) at a temperature of 25°C, a rotor model No. 63#, and a rotation speed of 12 RPM. The test conditions were: test time = 3 minutes, data collection duration = 2 minutes, and data collection method: single-point averaging.

[0084] The spray adhesive obtained in the example and the adhesive obtained in the comparative example were prepared into slurries, and their powdering phenomenon and bonding performance were measured.

[0085] Slurry preparation process and formula: Add 228.67g of water and 58.33g of spray glue (12%) to a 1000mL beaker, stir with a high-speed disperser at 500r / min for 5min, then slowly add 63g of PVDF or PMMA powder. After adding the powder, increase the speed to 2000r / min and disperse for 120min, then add 350g of water, reduce the speed to 1000r / min and disperse for 10min to obtain a slurry.

[0086] Slurry particle size detection method: Use a laser particle size analyzer to test the particle size of the dispersed slurry sample (for specific operation methods, refer to the SOP-MAStersizer 3000 operating procedures). Test parameter setting Analysis mode: General Particle type: spherical Opacity: 4-10% Material name: PAN Refractive index: 1.52 Absorption rate: 0.01 Medium: Water.

[0087] Spraying method: The prepared slurry is sprayed on the PP film with a spray gun, and the spraying surface density is controlled at 0.1g / m2 ; Spraying parameters: spraying pressure 0.2MPa, feeding speed 50Hz, diaphragm belt speed 3~5m / min.

[0088] Powder shedding evaluation: Use a cotton swab to gently wipe the sprayed diaphragm surface, and divide it into four levels according to the number of times the powder is wiped off: 0-20 times of powder shedding is marked as level one, 20-50 times of powder shedding is marked as level two, 50-100 times of powder shedding is marked as level three, and >100 times of no powder shedding is marked as level four.

[0089] Adhesion Test: In an environment with a humidity of 0.5% RH, cut the sprayed separator into 4cm x 20cm strips. Take a 5cm x 20cm cut positive or negative electrode sheet, and laminate the sprayed surface of the separator to the positive or negative electrode sheet. Roll the sheet onto a 3cm wide PP sheet to form a 3cm wide and 5cm long cold pressing sample. Prepare at least three samples. Place the sample in a cold press and cold press at 25°C, 3MPa, and 1min. Conduct the adhesion test in accordance with GB / T 2790-1995, Test Method for 180° Peel Strength of Adhesives. Apply double-sided tape to the test surface of the tensile testing machine, laminate the electrode sheet onto the tape, and connect the separator to the tensile testing machine with a traction tape. Turn on the tensile testing machine and read the value T when the display is stable. The test environment is: temperature 25°C, and adhesion test humidity 25% RH. The average value of multiple measurements is taken, and the bonding force = ΔT / 0.04 (N / m) (ΔT is the average value of multiple measurements), and the numerical value indicates the strength of the bonding force.

[0090] The test results are shown in Table 3.

[0091] Table 3 Note: “×” means the test conditions are not met and the test cannot be performed.

[0092] "Demulsification" means that the emulsion breaks during the pulping process, causing the powder to agglomerate and become unusable for spraying.

Claims

1. Spray adhesive for battery separator, characterized by: The graft polymer comprises an acrylonitrile polymer as the main chain, grafted polymer latex particles, and the polymer latex particles account for 65 to 85% of the weight percentage of the graft polymer, wherein: The polymerization monomers of the acrylonitrile polymer include acrylonitrile monomers, acrylic acid monomers and acrylamide monomers; the polymerization monomers of the polymer latex particles include acrylate monomers.

2. The spray adhesive for battery separator according to claim 1, characterized in that: The polymerization monomers of the polymer latex particles further include at least one of styrene monomers and acrylonitrile monomers.

3. The spray adhesive for battery separator according to claim 2, characterized in that: The acrylonitrile monomer includes at least one of acrylonitrile and methacrylonitrile; The acrylic monomer includes at least one of acrylic acid, methacrylic acid, allyloxyhydroxypropyl sulfonic acid, vinyl sulfonic acid, 2-acrylamide-2-methylpropane sulfonic acid, propylene sulfonic acid, methpropylene sulfonic acid, itaconic acid, and maleic acid; The acrylamide monomer includes at least one of acrylamide, methacrylamide, N-ethylacrylamide, N-hydroxymethylacrylamide, N-hydroxyethylacrylamide, and N-hydroxypropylacrylamide; The acrylic acid ester monomers include at least one of methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, butyl acrylate, butyl methacrylate, n-octyl acrylate, isooctyl acrylate, isooctyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, lauryl acrylate, lauryl methacrylate, octadecyl acrylate, octadecyl methacrylate, isobornyl acrylate, and isobornyl methacrylate; The styrene monomers include at least one of styrene, p-fluorostyrene, methylstyrene, m-fluorostyrene, o-fluorostyrene, sodium styrene sulfonate, p-methoxystyrene, o-methylstyrene, and p-methylstyrene.

4. The spray adhesive for battery separator according to claim 1, characterized in that: The weight ratio of acrylonitrile monomer, acrylic acid monomer and acrylamide monomer is 30-60:30-50:8-20.

5. The spray adhesive for battery separator according to claim 4, characterized in that: The weight ratio of acrylonitrile monomer, acrylic acid monomer and acrylamide monomer is 50:35:

15.

6. The spray adhesive for battery separator according to claim 1, characterized in that: The weight percentage of the polymer latex particles to the graft polymer is 75%.

7. The spray adhesive for battery separator according to any one of claims 1 to 6, characterized in that: Also included is a solvent, which is water.

8. The spray adhesive for battery separator according to claim 7, characterized in that: The viscosity thereof is 500 to 30,000 mPa·s when measured at 25° C. with a solid content of 12%.

9. Use of the spray adhesive for battery separator according to any one of claims 1 to 8 in spraying battery separator.

10. Use of the spray adhesive for battery separator according to claim 9 in spraying battery separator, characterized in that: The battery separator is a PP separator or a PE separator.

11. Battery separator spraying slurry, characterized by: The invention comprises polymer particles and the spray adhesive for battery separator according to any one of claims 1 to 8.

12. A battery separator, characterized in that: It comprises a base film and a coating on the surface of the base film, and the coating is sprayed with the battery separator spray slurry according to claim 11.

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