Photocuring ink, insulating coating, battery shell, preparation method of battery shell and battery

Abstract

The invention provides light-cured printing ink, an insulating coating, a battery shell, a preparation method of the battery shell and a battery. The light-cured printing ink comprises acrylic resin and an active monomer, and the acrylic resin comprises polyester type polyurethane acrylate resin and bisphenol type epoxy acrylate resin; the mass ratio of the polyester type polyurethane acrylate resin to the bisphenol type epoxy acrylate resin is (3-6): 1; the mass ratio of the polyester type urethane acrylate resin to the bisphenol type epoxy acrylate resin is controlled within the range of (3-6): 1, so that the insulating coating has good flexibility and thermal shrinkage shape energy at the same time, the insulating coating is not prone to brittle rupture and thermal shrinkage, and the high temperature resistance and mechanical property of the insulating coating are improved.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and in particular relates to a photocurable ink, an insulating coating, a battery casing, a preparation method thereof, and a battery. Background Art

[0002] Currently, lithium-ion batteries generally have aluminum shells. In order to improve the electrical insulation performance of the lithium-ion battery surface, a spray printing process is generally used to print a layer of insulating ink on the surface of the aluminum shell, and then the insulating ink is photocured to obtain an integrated insulating coating.

[0003] However, in the related art, the insulating coating is prone to brittle cracking and thermal shrinkage, and the insulating coating cannot simultaneously have good high-temperature resistance and mechanical properties, and needs further improvement. Summary of the Invention

[0004] The embodiments of the present application provide a photocurable ink, an insulating coating, a battery housing, a preparation method thereof, and a battery, aiming to solve the aforementioned technical problems.

[0005] In a first aspect, an embodiment of the present application provides a light-curable ink, comprising: an acrylic resin and a reactive monomer;

[0006] The acrylic resin includes a polyester polyurethane acrylate resin and a bisphenol epoxy acrylate resin, and the mass ratio of the polyester polyurethane acrylate resin to the bisphenol epoxy acrylate resin is (3-6):1.

[0007] In one embodiment, the bisphenol epoxy acrylate resin includes one or more of bisphenol A epoxy acrylate resin, bisphenol S epoxy acrylate resin, and bisphenol F epoxy acrylate resin; and / or

[0008] The mass percentage of the acrylic resin in the light-curable ink is 20%-40%; and / or

[0009] The mass percentage of the active monomer in the photocurable ink is 50%-70%; and / or

[0010] The mass ratio of the active monomer to the acrylic resin is (1.2-3.5):1; and / or

[0011] The reactive monomers include monofunctional acrylate monomers, difunctional acrylate monomers and multifunctional acrylate monomers, and the functionality of the multifunctional acrylate monomers is greater than or equal to 3; and / or

[0012] The molecular weight of the polyester polyurethane acrylate resin is 1000-1500; and / or

[0013] The molecular weight of the bisphenol epoxy acrylate resin is 1000-1500; and / or

[0014] The polyester polyurethane acrylate resin has the general structural formula shown in structural formula (1):

[0015]

[0016] and / or

[0017] The bisphenol epoxy acrylate resin has a general structural formula shown in structural formula (2):

[0018]

[0019] In one embodiment, in the structural formula (1), R2, R5, and R6 are each independently selected from a C1-C6 alkyl group, and / or R4 is selected from a hexamethylene group or an isophorone group, and / or m is selected from an integer of 2-10; and / or

[0020] In the structural formula (2), R1 is selected from hydrogen or C1-C6 alkyl, and / or n is selected from an integer of 2-10; and / or

[0021] The mass ratio of the monofunctional acrylate monomer, the difunctional acrylate monomer and the multifunctional acrylate monomer is (4-6):1:(0.1-0.4); and / or

[0022] The monofunctional acrylate monomer includes at least one of isobornyl acrylate, isodecyl acrylate, lauryl acrylate or hexadecyl acrylate; and / or

[0023] The bifunctional acrylate monomer includes at least one of 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, and ethoxylated bisphenol A diacrylate; and / or

[0024] The multifunctional acrylate monomer includes at least one of trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol penta / hexaacrylate, and tris(2-hydroxyethyl)isocyanurate triacrylate.

[0025] In one embodiment, the photocurable ink further includes an initiator, a pigment, an auxiliary agent and / or a diluent.

[0026] In one embodiment, the initiator includes a deep curing initiator, a thioxanthone initiator and an amine initiator, and the absorption wavelength of the deep curing initiator is 300nm-400nm; and / or

[0027] The auxiliary agents include wetting agents and adhesion agents; and / or

[0028] The diluent includes at least one of isobornyl acrylate, isodecyl acrylate, lauryl acrylate or hexadecyl acrylate.

[0029] In one embodiment, the mass percentage of the initiator in the photocurable ink is 2%-5%; and / or

[0030] The mass percentage of the pigment in the light-curable ink is 0.5%-1%; and / or

[0031] The mass percentage of the auxiliary agent in the light-curable ink is 1%-3%; and / or

[0032] The mass percentage of the diluent in the light-curable ink is 4%-5%; and / or

[0033] The particle size D50 of the pigment is ≤0.4 μm.

[0034] In one embodiment, the deep curing initiator includes at least one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, bis(1-(2,4-difluorophenyl)-3-pyrrolyl)titanocene, bis-2,6-difluoro-3-pyrrolphenyltitanocene, 2-hydroxy-2-methyl-1-phenylpropanone, and 1-hydroxycyclohexylphenyl ketone; and / or

[0035] The thioxanthone initiator includes at least one of 2-chlorothioxanthone, isopropylthioxanthone and 2,4-diethylthioxanthone; and / or

[0036] The amine initiator comprises at least one of an active amine and a tertiary amine benzoate; and / or

[0037] The wetting agent comprises at least one of polyether-modified silicone and polyester-modified silicone; and / or

[0038] The adhesive comprises at least one of phosphate-modified acrylate and silane-modified polymer; and / or

[0039] The mass percentage of the deep curing initiator in the photocurable ink is 2%-5%; and / or

[0040] The sum of the mass percentage of the thioxanthone initiator and the amine initiator in the photocurable ink is 1% to 3% by mass; and / or

[0041] The mass ratio of the thioxanthone initiator to the amine initiator is 1:(0.2-0.5).

[0042] In one embodiment, the active amine includes at least one of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexamethylenediamine, diethylamine, triethylamine, isophoronediamine, and 1,2-cyclohexanediamine; and / or

[0043] The tertiary amine benzoate includes at least one of ethyl 4-(N,N-dimethylamino)benzoate, ethyl N,N-diphenylmethylcarboxylate, and 2-ethylhexyl N,N-dimethylbenzoate.

[0044] In a second aspect, an embodiment of the present application further provides an insulating coating, wherein the insulating coating is formed by the photocurable ink as described above.

[0045] In a third aspect, an embodiment of the present application further provides a battery housing, comprising:

[0046] Main body;

[0047] An insulating coating layer is provided on at least a portion of the outer surface of the main body, and the insulating coating layer is formed of the light-curable ink as described above.

[0048] In a fourth aspect, an embodiment of the present application further provides a method for preparing a battery casing, the method comprising:

[0049] providing a main body portion of a battery housing;

[0050] Using the aforementioned light-curable ink as a raw material, spraying an ink layer on at least a portion of the outer surface of the main body;

[0051] The ink layer is cured by ultraviolet light irradiation to form an insulating coating, thereby obtaining the battery shell.

[0052] In one embodiment, the thickness of the ink layer is 50 μm-150 μm; and / or

[0053] The light source of the ultraviolet light includes an electrodeless lamp, and / or the wavelength of the ultraviolet light is 200nm-450nm, and / or the curing time is 1s-10s.

[0054] In a fifth aspect, an embodiment of the present application further provides a battery, comprising the insulating coating as described above, or comprising the battery casing as described above, or a battery casing prepared using the method as described above.

[0055] Beneficial effects of the embodiments of the present application:

[0056] The photocurable ink of the present embodiment includes an acrylic resin and a reactive monomer. A photocuring reaction occurs between the acrylic resins, between the reactive monomers, and / or between the acrylic resin and the reactive monomers under illumination to form a polymer. The acrylic resin includes a polyester polyurethane acrylate resin and a bisphenol epoxy acrylate resin, with the mass ratio of the polyester polyurethane acrylate resin to the bisphenol epoxy acrylate resin being (3-6):1. The polyester polyurethane acrylate resin has polyester segments, which improve the polymer's flexibility, high-temperature and high-humidity resistance, and chemical stability. The bisphenol epoxy acrylate resin has a rigid structure, such as a benzene ring, which improves the polymer's thermal shrinkage and electrical insulation properties. When the mass ratio of the polyester polyurethane acrylate resin to the bisphenol epoxy acrylate resin is less than 3:1, the polyester polyurethane acrylate resin content is likely to be too low, while the bisphenol epoxy acrylate resin content is too high, resulting in excessive rigidity and low flexibility of the polymer. This makes the insulating coating formed by the photocurable ink prone to brittle cracking and poor high temperature and high humidity resistance. When the mass ratio of the polyester polyurethane acrylate resin to the bisphenol epoxy acrylate resin is greater than 6:1, the polyester polyurethane acrylate resin content is likely to be too high, while the bisphenol epoxy acrylate resin content is too low. This makes the polymer's thermal shrinkage and insulation properties too low, and the insulating coating formed by the photocurable ink prone to high temperature shrinkage. Controlling the mass ratio of the polyester polyurethane acrylate resin to the bisphenol epoxy acrylate resin within the range of (3-6):1 can ensure that the insulating coating has both good flexibility and thermal shrinkage properties, making the insulating coating less prone to brittle cracking and thermal shrinkage, and improving the high temperature resistance and mechanical properties of the insulating coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] To more clearly illustrate the solutions in the present application or the prior art, a brief introduction to the drawings required for use in the embodiments or descriptions of the prior art is provided below. Obviously, the drawings described below are some embodiments of the present application. A person skilled in the art can derive other drawings based on these drawings without inventive effort.

[0058] Figure 1 This is a graph showing the test results of the insulating coating of Example 1 after aging treatment using the hundred-grid method;

[0059] Figure 2 This is a graph showing the test results of the insulating coating of Example 7 after aging treatment using the hundred-grid method;

[0060] Figure 3 This is a graph showing the test results of the insulating coating of Example 9 after aging treatment using the hundred-grid method;

[0061] Figure 4 This is a graph showing the test results of the insulating coating of Comparative Example 2 after aging treatment using the hundred-grid method;

[0062] Figure 5 This is a graph showing the results of the insulating coating of Comparative Example 1 tested using the hundred-grid method after aging treatment. DETAILED DESCRIPTION

[0063] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application. In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise specified, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state; while "inside" and "outside" refer to the outline of the device.

[0064] In the related art, the insulating coating is prone to brittle cracking and thermal shrinkage, and the insulating coating cannot simultaneously have good high-temperature resistance and mechanical properties, and needs further improvement.

[0065] The present application provides a photocurable ink comprising an acrylic resin and a reactive monomer. A photocurable reaction can occur between the acrylic resins, between the reactive monomers, and / or between the acrylic resin and the reactive monomers under illumination to form a polymer. The acrylic resin comprises a polyester polyurethane acrylate resin and a bisphenol epoxy acrylate resin, wherein the mass ratio of the polyester polyurethane acrylate resin to the bisphenol epoxy acrylate resin is (3-6):1. The polyester polyurethane acrylate resin comprises polyester segments, which can improve the polymer's flexibility, high-temperature and high-humidity resistance, and chemical stability. The bisphenol epoxy acrylate resin comprises a rigid structure, such as a benzene ring, which can improve the polymer's thermal shrinkage and electrical insulation properties. When the mass ratio of the polyester polyurethane acrylate resin to the bisphenol epoxy acrylate resin is less than 3:1, the polyester polyurethane acrylate resin content is likely to be too low, while the bisphenol epoxy acrylate resin content is too high, resulting in excessive rigidity and low flexibility of the polymer. This makes the insulating coating formed by the photocurable ink prone to brittle cracking and poor high temperature and high humidity resistance. When the mass ratio of the polyester polyurethane acrylate resin to the bisphenol epoxy acrylate resin is greater than 6:1, the polyester polyurethane acrylate resin content is likely to be too high, while the bisphenol epoxy acrylate resin content is too low. This makes the polymer's thermal shrinkage and insulation properties too low, and the insulating coating formed by the photocurable ink prone to high temperature shrinkage. Controlling the mass ratio of the polyester polyurethane acrylate resin to the bisphenol epoxy acrylate resin within the range of (3-6):1 can ensure that the insulating coating has both good flexibility and thermal shrinkage properties, making the insulating coating less prone to brittle cracking and thermal shrinkage, and improving the high temperature resistance and mechanical properties of the insulating coating.

[0066] In this embodiment, the mass ratio of the polyester polyurethane acrylate resin to the bisphenol epoxy acrylate resin can be any one of 3:1, 4:1, 5:1, 6:1, etc., or a range between any two of them, which is not limited here.

[0067] In this embodiment, the bisphenol epoxy acrylate resin may include one or more of bisphenol A epoxy acrylate resin, bisphenol S epoxy acrylate resin, and bisphenol F epoxy acrylate resin, which are not limited here.

[0068] In one embodiment, the mass percentage of acrylic resin in the photocurable ink is 20%-40%; alternatively, the mass percentage of acrylic resin in the photocurable ink can be any one of 20%, 25%, 30%, 35%, 40%, or any two thereof, without limitation. In this embodiment, if the mass percentage of acrylic resin in the photocurable ink is too high, the viscosity of the photocurable ink at room temperature may increase, limiting the penetration of ultraviolet light into the photocurable ink and resulting in poor curing. Furthermore, it may increase resin shrinkage stress, resulting in reduced peel strength between the insulating coating and the main body of the battery casing. If the mass percentage of acrylic resin in the photocurable ink is too low, the electrical insulation performance, high-temperature resistance, chemical stability, and mechanical properties of the insulating coating may be reduced.

[0069] In one embodiment, the mass ratio of the active monomer to the acrylic resin is (1.2-3.5):1. Optionally, the mass ratio of the active monomer to the acrylic resin can be any one of 1.2:1, 1.5:1, 1.8:1, 2.0:1, 2.5:1, 3.0:1, 3.2:1, 3.5:1, etc., or a range between any two thereof, and is not limited here. In this embodiment, if the mass ratio of the active monomer to the acrylic resin is too large, it is easy to cause the content of the active monomer to be excessive and the content of the acrylic resin to be too low. Excessive active monomers are likely to reduce the crosslinking density of the acrylic resin. In addition, the more active monomers there are, the higher the UV energy required for complete curing. Under limited UV energy, excessive active monomers are likely to lead to incomplete curing, resulting in a decrease in the mechanical properties, high temperature resistance, and electrical insulation properties of the insulating coating. If the mass ratio of the active monomer to the acrylic resin is too small, it is easy to cause the content of the active monomer to be too low and the content of the acrylic resin to be too high, the viscosity of the photocurable ink at room temperature to increase, the penetration of ultraviolet light into the photocurable ink to be limited, and the curing effect of the photocurable ink to be poor; at the same time, it is easy to cause the shrinkage stress of the resin to increase, resulting in a decrease in the peel strength between the insulating coating and the main body of the battery shell.

[0070] In one embodiment, the molecular weight of the polyester polyurethane acrylate resin is 1000-1500. Alternatively, the molecular weight of the polyester polyurethane acrylate resin may be any one of 1000, 1100, 1200, 1300, 1400, 1500, or any two thereof, without limitation. In this embodiment, the molecular weight of the polyester polyurethane acrylate resin is set to 1000-1500 to ensure that the UV-curable ink has an appropriate viscosity, thereby reducing ink smearing and clogging during spraying.

[0071] In one embodiment, the molecular weight of the bisphenol epoxy acrylate resin is 1000-1500. Alternatively, the molecular weight of the bisphenol epoxy acrylate resin may be any one of 1000, 1100, 1200, 1300, 1400, 1500, or any two thereof, without limitation. In this embodiment, the molecular weight of the bisphenol epoxy acrylate resin is set to 1000-1500 to ensure that the UV-curable ink has an appropriate viscosity, thereby reducing ink smearing and clogging during spraying.

[0072] In one embodiment, the polyester polyurethane acrylate resin has the general structural formula shown in structural formula (1):

[0073]

[0074] In this embodiment, the polyester-type polyurethane acrylate resin has a polyester chain segment, which can improve the flexibility, high temperature and high humidity resistance and chemical stability of the polymer; in addition, the polyester-type polyurethane acrylate resin has multiple polar groups such as carbonyl groups and alkoxy groups, which can form chemical bonds or van der Waals forces with the main body of the battery shell to improve the adhesion of the insulating coating.

[0075] In one embodiment, in structural formula (1), R2, R5, and R6 are each independently selected from a C1-C6 alkyl group, and / or R4 is selected from a hexamethylene group or an isophorone group, and / or m is selected from an integer of 2-10.

[0076] In one embodiment, the polyester polyurethane acrylate resin represented by structural formula (1) can be prepared by the following method:

[0077] S11. Add a polyester polyol having a structure as shown in Formula 1 and an isocyanate having a structure as shown in Formula 2 to a reaction vessel containing an acetone solvent and mix them evenly to obtain a first mixed solution. Add dibutyltin dilaurate and triethylenediamine as catalysts to the first mixed solution, and conduct a polycondensation reaction at an ambient temperature of 60°C-80°C for 4-12 hours to obtain a compound represented by Formula 3. The molar ratio of the polyester polyol to the isocyanate is 2:1, and the mass percentage of the catalyst in the first mixed solution is 0.1%-0.5%. The reaction formula is as follows:

[0078]

[0079] S12. Add an acrylate having a structure as shown in Formula 4 to a reaction vessel, and continue the reaction at an ambient temperature of 60°C to 80°C for 4 to 12 hours to obtain a polyester polyurethane acrylate resin represented by structural formula (1); wherein the molar ratio of the acrylate to the polyester polyol is 2:1. The reaction formula is as follows:

[0080]

[0081] In this embodiment, the polyester polyol may include at least one of adipic acid polyester polyol, sebacic acid polyester polyol, terephthalic acid polyester polyol and phthalic acid polyester polyol; the isocyanate may include at least one of isophorone diisocyanate and hexamethylene diisocyanate.

[0082] In one embodiment, the bisphenol epoxy acrylate resin has the general structural formula shown in structural formula (2):

[0083]

[0084] In this embodiment, the bisphenol epoxy acrylate resin has a rigid structure such as a benzene ring, which can improve the thermal shrinkage and electrical insulation properties of the polymer.

[0085] In one embodiment, in structural formula (2), R1 is selected from hydrogen or C1-C6 alkyl, and / or n is selected from an integer of 2-10.

[0086] In one embodiment, the bisphenol epoxy acrylate resin represented by structural formula (2) can be prepared by the following method:

[0087] S21. Add bisphenol A and ethylene chloride to a reaction vessel containing acetone solvent and mix thoroughly to obtain a first mixed solution. Add sodium hydroxide as a catalyst to the first mixed solution and conduct a polycondensation reaction at an ambient temperature of 50°C-100°C for 2-12 hours to obtain the compound represented by Formula 5. The molar ratio of bisphenol A to ethylene chloride is 2:3, and the mass percentage of the catalyst in the first mixed solution is 0.1%-1%. The reaction formula is as follows:

[0088]

[0089] S22. Add triethylamine catalyst and an acrylic compound having a structure as shown in Formula 6 to a reaction vessel, and react at an ambient temperature of 25°C to 80°C for 2 to 12 hours to obtain a bisphenol-type epoxy acrylate resin represented by structural formula (2); wherein the molar ratio of acrylic acid to bisphenol A is 2:1. The reaction formula is as follows:

[0090]

[0091] In one embodiment, the mass percentage of the active monomer in the photocurable ink is 50%-70%. Alternatively, the mass percentage of the active monomer in the photocurable ink can be any one of 50%, 55%, 60%, 65%, 70%, or any two thereof, without limitation herein. In this embodiment, if the mass percentage of the active monomer in the photocurable ink is too high, the excess active monomer can easily reduce the crosslinking density of the acrylic resin, resulting in a decrease in the mechanical properties of the insulating coating. Furthermore, the more active monomer, the higher the UV energy required for complete curing. Given limited UV energy, excessive active monomer can easily lead to incomplete curing. The active monomer can reduce the viscosity of the photocurable ink. If the mass percentage of the active monomer in the photocurable ink is too low, the viscosity of the photocurable ink can easily increase, limiting the penetration of ultraviolet light into the photocurable ink and resulting in poor curing of the photocurable ink.

[0092] In one embodiment, the reactive monomers include monofunctional acrylate monomers, difunctional acrylate monomers, and multifunctional acrylate monomers, wherein the functionality of the multifunctional acrylate monomers is greater than or equal to 3. In this embodiment, the monofunctional acrylate monomers can increase the flexibility and adhesion of the insulating coating, while the difunctional acrylate monomers and multifunctional acrylate monomers can improve the electrical insulation, electrolyte resistance, and crosslink density of the insulating coating. The combined use of the monofunctional acrylate monomers, difunctional acrylate monomers, and multifunctional acrylate monomers can produce a synergistic effect, improving the flexibility, electrical insulation, solvent resistance, and adhesion of the insulating coating.

[0093] In one embodiment, the mass ratio of the monofunctional acrylate monomer, the difunctional acrylate monomer, and the multifunctional acrylate monomer is (4-6):1:(0.1-0.4). Optionally, the mass ratio of the monofunctional acrylate monomer, the difunctional acrylate monomer, and the multifunctional acrylate monomer can be any one of 4:1:0.4, 4:1:0.3, 4:1:0.2, 4:1:0.1, 6:1:0.1, etc., or a range between any two of them, which is not limited here. In this embodiment, when the mass of the monofunctional acrylate monomer is too much and the mass of the multifunctional acrylate monomer is too little, it is easy to cause the cross-linking density of the insulating coating to be too low and the high temperature resistance to be poor. When the mass of the monofunctional acrylate monomer is too little and the mass of the multifunctional acrylate monomer is too much, it is easy to cause the insulating coating to be incompletely cured, the insulating coating to be sticky, the insulating coating to be easily brittle, and the aging resistance to be poor.

[0094] In one embodiment, the monofunctional acrylate monomer includes at least one of isobornyl acrylate, isodecyl acrylate, lauryl acrylate, or hexadecyl acrylate.

[0095] In one embodiment, the bifunctional acrylate monomer includes at least one of 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, and ethoxylated bisphenol A diacrylate.

[0096] In one embodiment, the multifunctional acrylate monomer includes at least one of trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol penta / hexaacrylate, and tris(2-hydroxyethyl)isocyanurate triacrylate.

[0097] In one embodiment, the photocurable ink further includes an initiator, a pigment, an auxiliary agent and / or a diluent.

[0098] In one embodiment, the initiator includes a deep curing initiator, a thioxanthone initiator and an amine initiator, and the absorption wavelength of the deep curing initiator is 300nm-400nm. The initiator can promote the polymerization reaction of the polymer monomer and the acrylic resin to achieve the curing of the photocurable ink. The initiator includes a deep curing initiator, a thioxanthone initiator and an amine initiator, and the absorption wavelength of the deep curing initiator is 300nm-400nm. Generally, the longer the wavelength of light, the better the ability of light to penetrate the material. Therefore, the ink in the deep area usually requires longer wavelength light during photocuring, and the absorption wavelength of the deep curing initiator is 300nm-400nm. The deep curing initiator can absorb light that matches the longer wavelength, ensuring that the deep curing initiator can also be effectively activated to generate free radicals in the deep area, thereby achieving deep curing. Thioxanthone initiators can meet the needs of surface curing due to their high absorption efficiency and rapid initiation ability. Thioxanthone initiators form an excited state under light. The electron-rich sulfur atoms in the molecular structure of thioxanthone initiators enhance the molecule's ability to absorb light, allowing the excited state to be efficiently generated. The excited state thioxanthone initiators extract hydrogen atoms from amine initiators through intramolecular hydrogen abstraction reactions to generate active free radicals and amine free radicals. Amine free radicals can react with oxygen to generate peroxyamines, which in turn consume oxygen in the surface area, thereby reducing the interference of oxygen on surface curing, allowing the surface area to complete surface curing before oxygen diffuses to the reaction interface, improving the oxygen inhibition problem, and improving the surface curing effect of the insulating coating. When the light-curing ink is cured, both surface curing and bottom curing can be achieved simultaneously.

[0099] In one embodiment, the mass percentage of the initiator in the photocurable ink is 2%-5%. Alternatively, the mass percentage of the initiator in the photocurable ink can be any one of 2%, 2.5%, 3%, 3.5%, 4%, 5%, or any range between two of these, without limitation. In this embodiment, excessive initiator content can lead to an overly rapid curing reaction, potentially causing internal stress or cracks in the insulating coating. Excessive initiator content can result in incomplete curing, impacting the mechanical strength and durability of the insulating coating.

[0100] In one embodiment, the combined mass percentage of the thioxanthone initiator and the amine initiator in the photocurable ink is 1%-3%. Alternatively, the combined mass percentage of the thioxanthone initiator and the amine initiator in the photocurable ink can be any one of 1%, 1.5%, 2%, 2.5%, 3%, or any two thereof, without limitation. In one embodiment, if the combined mass percentage of the thioxanthone initiator and the amine initiator is too high, the ink surface may cure too quickly, resulting in an uneven surface. This may cause defects such as orange peel and craters on the insulating coating surface, affecting the appearance and performance of the insulating coating. If the combined mass percentage of the thioxanthone initiator and the amine initiator is too low, the ink surface may not fully cure.

[0101] In one embodiment, the mass ratio between the thioxanthone initiator and the amine initiator is 1:(0.2-0.5). Optionally, the mass ratio between the thioxanthone initiator and the amine initiator can be any one of 1:0.2, 1:0.3, 1:0.4, 1:0.5, etc., or a range between any two of them, which is not limited here. In this embodiment, the thioxanthone initiator mainly generates free radicals with the amine initiator through hydrogen abstraction reaction to promote ink curing. When the mass ratio between the thioxanthone initiator and the amine initiator is too low, it is easy to cause the thioxanthone initiator to generate too few free radicals, and the initiation efficiency of the amine initiator alone is low, resulting in a slow curing speed and incomplete surface curing. When the mass ratio between the thioxanthone initiator and the amine initiator is too high, it is easy to cause the content of the amine initiator to be too low, and the effect of the amine initiator in improving oxygen inhibition is not ideal.

[0102] In one embodiment, the mass percentage of the deep-layer curing initiator in the photocurable ink is 2%-5%. Alternatively, the mass percentage of the deep-layer curing initiator in the photocurable ink may be any one of 2%, 2.5%, 3%, 3.5%, 5%, or any range between two of these, without limitation. In this embodiment, if the mass percentage of the deep-layer curing initiator in the photocurable ink is too high or too low, the insulating coating may exhibit poor consistency in the degree of curing between the surface layer and the deep layer.

[0103] In one embodiment, the deep curing initiator includes at least one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, bis(1-(2,4-difluorophenyl)-3-pyrrolyl)titanocene, bis-2,6-difluoro-3-pyrrolphenyltitanocene, 2-hydroxy-2-methyl-1-phenylpropanone, and 1-hydroxycyclohexylphenyl ketone.

[0104] In one embodiment, the thioxanthone initiator includes at least one of 2-chlorothioxanthone, isopropylthioxanthone, and 2,4-diethylthioxanthone.

[0105] In one embodiment, the amine initiator includes at least one of an active amine and a tertiary amine benzoate.

[0106] In one embodiment, the active amine includes at least one of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexamethylenediamine, diethylamine, triethylamine, isophoronediamine, and 1,2-cyclohexanediamine.

[0107] In one embodiment, the tertiary amine benzoate includes at least one of ethyl 4-(N,N-dimethylamino)benzoate, ethyl N,N-diphenylmethanecarboxylate, and 2-ethylhexyl N,N-dimethylbenzoate.

[0108] In one embodiment, the auxiliary agent includes a wetting agent and an adhesion agent, which can improve the spreadability and anti-cratering properties of the light-curable ink.

[0109] In one embodiment, the mass percentage of the additive in the photocurable ink is 1%-3%; optionally, the mass percentage of the additive in the photocurable ink can be any one of 1%, 1.5%, 2%, 2.5%, 3%, etc., or a range between any two of them, which is not limited here.

[0110] In one embodiment, the wetting agent includes at least one of polyether-modified silicone and polyester-modified silicone.

[0111] In one embodiment, the adhesive includes at least one of phosphate-modified acrylate and silane-modified polymer.

[0112] In one embodiment, the mass percentage of the diluent in the ink is 4%-5%. Alternatively, the mass percentage of the diluent in the light-curable ink can be any one of 4%, 4.2%, 4.6%, 4.8%, 5%, etc., or a range between any two of them, without limitation.

[0113] In one embodiment, the diluent includes at least one of isobornyl acrylate, isodecyl acrylate, lauryl acrylate, or hexadecyl acrylate.

[0114] In one embodiment, the mass percentage of the pigment in the photocurable ink is 0.5%-1%. Alternatively, the mass percentage of the pigment in the photocurable ink can be any one of 0.5%, 0.6%, 0.7%, 0.8%, 1%, etc., or a range between any two of them, without limitation.

[0115] In one embodiment, the particle size D50 of the pigment is ≤ 0.4 μm.

[0116] In one embodiment, the pigment includes at least one of phthalocyanine blue powder, phthalocyanine green powder, and titanium dioxide.

[0117] The present application also provides a method for preparing a photocurable ink, comprising: adding raw materials such as acrylic resin and active monomer into a double planetary mixer, and dispersing them at 500 r / min-1000 r / min for 0.5 h-1 h to obtain the photocurable ink.

[0118] The present application also provides an insulating coating, which is formed by the photocurable ink as described above.

[0119] The present application also provides a battery housing comprising a main body and an insulating coating, the insulating coating being disposed on at least a portion of the outer surface of the main body and being formed from the photocurable ink described above. In this embodiment, the main body can be made of a material having a certain hardness and strength, such as copper, iron, aluminum, stainless steel, or an aluminum alloy, without limitation. The shape of the main body is also not limited, and can be a rectangular parallelepiped, cylindrical, hexagonal prism, or the like, without limitation.

[0120] The present application also provides a method for preparing a battery casing, comprising:

[0121] S01. Providing a main body of a battery casing;

[0122] S02, using the above-mentioned light-curable ink as a raw material, spraying an ink layer on at least a portion of the outer surface of the main body;

[0123] S03. The ink layer is cured by ultraviolet light to form an insulating coating, thereby obtaining a battery shell.

[0124] In this embodiment, a spraying process is adopted to spray a layer of ink on the surface of the main body, and ultraviolet light is used for photocuring. The ink layer can be cured in situ on the surface of the main body, which can improve the adhesion of the insulating coating on the main body. At the same time, the insulating coating has good flexibility and thermal shrinkage properties, and the insulating coating is not prone to brittle cracking and thermal shrinkage.

[0125] In one embodiment, the thickness of the ink layer is 50 μm-150 μm; optionally, the thickness of the ink layer can be any one of 50 μm, 80 μm, 100 μm, 120 μm, 150 μm, etc. or a range between any two thereof, which is not limited here.

[0126] In one embodiment, the ultraviolet light source includes an electrodeless lamp, and / or the wavelength of the ultraviolet light is 200 nm-450 nm, and / or the curing time is 1 s-10 s.

[0127] The present application also provides a battery comprising the insulating coating described above, or comprising the battery casing described above, or a battery casing prepared using the method described above. In this embodiment, the type of battery is not limited, and the battery can be a lithium-ion battery, a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery.

[0128] The present application will be further described below through specific examples.

[0129] Example 1

[0130] This embodiment provides a photocurable ink, which includes an acrylic resin, a reactive monomer, an initiator, a pigment, an additive, and a diluent; wherein:

[0131] The mass percentage of the acrylic resin in the light-curing ink is 25%, and the acrylic resin is composed of a polyester polyurethane acrylate resin and a bisphenol A epoxy acrylate resin, and the mass ratio between the polyester polyurethane acrylate resin and the bisphenol A epoxy acrylate resin is 4:1;

[0132] The mass percentage of the active monomer in the light-curable ink is 64.5%, and the active monomer is composed of isobornyl acrylate, 1,6-hexanediol diacrylate and trimethylolpropane triacrylate, and the mass ratio between isobornyl acrylate, 1,6-hexanediol diacrylate and trimethylolpropane triacrylate is 4:1:0.2;

[0133] The mass percentage of the initiator in the light-curing ink is 3%, and the initiator consists of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-chlorothioxanthone and ethylenediamine.

[0134] The mass percentage of the pigment in the light-curing ink is 0.5%, and the pigment is titanium dioxide.

[0135] The mass percentage of the additive in the light-curing ink is 2%, and the additive includes polyether-modified silicone and phosphate-modified acrylate;

[0136] The mass percentage of the diluent in the light-curing ink is 5%, and the diluent is lauryl acrylate.

[0137] Example 2

[0138] The main difference between Example 2 and Example 1 is that:

[0139] The mass ratio between the polyester polyurethane acrylate resin and the bisphenol A epoxy acrylate resin is 3:1; the rest is the same as in Example 1.

[0140] Example 3

[0141] The main difference between Example 3 and Example 1 is that:

[0142] The mass ratio between the polyester polyurethane acrylate resin and the bisphenol A epoxy acrylate resin is 6:1; the rest is the same as in Example 1.

[0143] Example 4

[0144] The main difference between Example 4 and Example 1 is that:

[0145] The mass ratio of isobornyl acrylate, 1,6-hexanediol diacrylate and trimethylolpropane triacrylate is 4:1:0.4; the rest is the same as in Example 1.

[0146] Example 5

[0147] The main difference between Example 5 and Example 1 is that:

[0148] The mass ratio of isobornyl acrylate, 1,6-hexanediol diacrylate and trimethylolpropane triacrylate is 6:1:0.1; the rest is the same as in Example 1.

[0149] Example 6

[0150] The main difference between Example 6 and Example 1 is that:

[0151] The active monomers consist of isodecyl acrylate, ethoxylated bisphenol A diacrylate and propoxylated trimethylolpropane triacrylate; the rest are the same as in Example 1.

[0152] Example 7

[0153] The main difference between Example 7 and Example 1 is that:

[0154] The mass percentage of the acrylic resin in the light-curing ink is 20%, and the acrylic resin is composed of a polyester polyurethane acrylate resin and a bisphenol A epoxy acrylate resin, and the mass ratio between the polyester polyurethane acrylate resin and the bisphenol A epoxy acrylate resin is 3:1;

[0155] The mass percentage of the active monomer in the light-curable ink is 70%, and the active monomer is composed of isobornyl acrylate, 1,6-hexanediol diacrylate and trimethylolpropane triacrylate, and the mass ratio between isobornyl acrylate, 1,6-hexanediol diacrylate and trimethylolpropane triacrylate is 4:1:0.4;

[0156] The mass percentage of the diluent in the light-curing ink is 4.5%;

[0157] The rest is the same as in Example 1.

[0158] Example 8

[0159] The main difference between Example 8 and Example 1 is:

[0160] The mass percentage of the acrylic resin in the light-curing ink is 40%, and the acrylic resin is composed of a polyester polyurethane acrylate resin and a bisphenol A epoxy acrylate resin, and the mass ratio between the polyester polyurethane acrylate resin and the bisphenol A epoxy acrylate resin is 6:1;

[0161] The mass percentage of the active monomer in the light-curable ink is 50%, and the active monomer is composed of isobornyl acrylate, 1,6-hexanediol diacrylate and trimethylolpropane triacrylate, and the mass ratio between isobornyl acrylate, 1,6-hexanediol diacrylate and trimethylolpropane triacrylate is 6:1:0.1;

[0162] The mass percentage of the diluent in the light-curing ink is 4.5%;

[0163] The rest is the same as in Example 1.

[0164] Example 9

[0165] The main difference between Example 9 and Example 1 is that:

[0166] The mass ratio of isobornyl acrylate, 1,6-hexanediol diacrylate and trimethylolpropane triacrylate is 4:1:0.6; the rest is the same as in Example 1.

[0167] Example 10

[0168] The main difference between Example 10 and Example 1 is that:

[0169] The active monomer consists of isobornyl acrylate and 1,6-hexanediol diacrylate, and the mass ratio of isobornyl acrylate to 1,6-hexanediol diacrylate is 4:1. The rest is the same as in Example 1.

[0170] Example 11

[0171] The main differences between Example 11 and Example 1 are:

[0172] The mass percentage of the active monomer in the photocurable ink is 18.6%, and the mass percentage of the acrylic resin in the photocurable ink is 70.9%. The rest is the same as in Example 1.

[0173] Example 12

[0174] The main difference between Example 12 and Example 1 is that:

[0175] The mass percentage of the active monomer in the photocurable ink is 42.8%, and the mass percentage of the acrylic resin in the photocurable ink is 46.7%. The rest is the same as in Example 1.

[0176] Comparative Example 1

[0177] The main difference between Comparative Example 1 and Example 1 is:

[0178] The mass ratio of the polyester polyurethane acrylate resin to the bisphenol A epoxy acrylate resin is 2:1; the rest is the same as in Example 1.

[0179] Comparative Example 2

[0180] The main difference between Comparative Example 2 and Example 1 is:

[0181] The mass ratio between the polyester polyurethane acrylate resin and the bisphenol A epoxy acrylate resin is 7:1; the rest is the same as in Example 1.

[0182] Comparative Example 3

[0183] A 100 μm thick PET blue film was used instead of the insulating coating.

[0184] Test method:

[0185] The photocurable inks of Examples 1 to 12 and Comparative Examples 1 to 2 were sprayed on an aluminum sheet using an electrodeless lamp as a light source, a UV wavelength of 400 nm, and a curing time of 8 seconds to obtain an insulating coating having a thickness of 100 μm.

[0186] (1) 100-grid adhesion test

[0187] Using the GB / T 9286-2021 method for testing, the insulating coatings obtained in Examples 1 to 12 and Comparative Examples 1 to 2, as well as the PET blue film from Comparative Example 3, were adhered to the surface of a 150×100 mm aluminum plate and placed on a horizontal, rigid surface. A grid knife was used to cut perpendicular to the sample, ensuring that all cuts penetrated the substrate surface. A similar number of cuts were then made at 90° angles to the original cut lines to form a grid. A soft brush was then used to sweep the surface several times. Transparent tape was applied over the grid, flattened, and removed. The adhesion of the insulating coating was evaluated using the adhesion grading table, where Grade 0 indicates no coating peeling; Grade 1 indicates ≤5% peeling; Grade 2 indicates 5%-15% peeling; Grade 3 indicates 15%-35% peeling; Grade 4 indicates 35%-65% peeling; and Grade 5 indicates >65% peeling. The test results are shown in Table 1.

[0188] (2) Shear strength test

[0189] The insulating coatings obtained in Examples 1 to 12 and Comparative Examples 1 to 2, and the PET blue film of Comparative Example 3 were subjected to shear strength tests according to the method of GB / T 7124-2008. The test results are shown in Table 1.

[0190] (3) Insulation resistance test

[0191] The insulation properties of the insulating coatings obtained in Examples 1 to 12 and Comparative Examples 1 to 2, and the PET blue film of Comparative Example 3 were tested using an insulation withstand voltage tester at 1500V DC for 60 seconds to measure insulation resistance. The test results are shown in Table 1.

[0192] (4) High temperature resistance test

[0193] The insulating coatings obtained in Examples 1 to 12 and Comparative Examples 1 to 2, as well as the PET blue film of Comparative Example 3, were subjected to a high-temperature resistance test at 130°C for 48 hours. The samples were observed for abnormalities such as shrinkage, shedding, and cracking. The test results are shown in Table 1.

[0194] (5) Withstand voltage test

[0195] The insulating coatings obtained in Examples 1 to 12 and Comparative Examples 1 to 2, as well as the PET blue film of Comparative Example 3, were subjected to a withstand voltage test using an insulation withstand voltage tester. The test conditions were DC 4000 V, the test time was 60 s, and the leakage current was ≤ 0.1 mA. The test results are shown in Table 1.

[0196] (5) Aging test

[0197] The insulating coatings obtained in Examples 1 to 12 and Comparative Examples 1 to 2 and the PET blue film of Comparative Example 3 were aged using a constant temperature and humidity chamber. The aging temperature was 85°C, the relative humidity was 85%, and the aging time was 2000 hours. After aging, the insulating coatings were observed for cracking or shedding. At the same time, the shear strength, adhesion, withstand voltage performance, and insulation resistance of the insulating coatings after aging were tested. The test results are shown in Tables 2 and Figure 1-Figure 5 shown; among them, Figure 1 This is a graph showing the test results of the insulating coating of Example 1 after aging treatment using the hundred-grid method; Figure 2 This is a graph showing the test results of the insulating coating of Example 7 after aging treatment using the hundred-grid method; Figure 3 This is a graph showing the test results of the insulating coating of Example 9 after aging treatment using the hundred-grid method; Figure 4 This is a graph showing the test results of the insulating coating of Comparative Example 2 after aging treatment using the hundred-grid method; Figure 5 This is a graph showing the results of the insulating coating of Comparative Example 1 tested using the hundred-grid method after aging treatment.

[0198] Table 1:

[0199]

[0200]

[0201] Table 2:

[0202]

[0203]

[0204] From the test results of the above-mentioned Examples 1 to 12 and Comparative Examples 1 to 3, it can be seen that the insulating coatings prepared in Examples 1 to 12 have a hundred-grid adhesion of level 0 before aging treatment, a shear strength greater than or equal to 8.6 MPa, and no shrinkage after high-temperature treatment. The insulating coatings of the embodiments of the present application have both good high-temperature resistance and mechanical properties. The reason is that: the photocurable ink includes acrylic resin and active monomers, the acrylic resin includes polyester polyurethane acrylate resin and bisphenol epoxy acrylate resin, and the mass ratio of polyester polyurethane acrylate resin and bisphenol epoxy acrylate resin is (3-6):1; polyester polyurethane acrylate resin has polyester chain segments, which can improve the flexibility, high temperature and high humidity resistance and chemical stability of the polymer; bisphenol epoxy acrylate resin has rigid structures such as benzene rings, which can improve the thermal shrinkage and electrical insulation properties of the polymer. Controlling the mass ratio of polyester polyurethane acrylate resin and bisphenol epoxy acrylate resin in the range of (3-6):1 can make the insulating coating have good flexibility and thermal shrinkage properties at the same time, the insulating coating is not prone to brittle cracking and thermal shrinkage, and the high temperature resistance and mechanical properties of the insulating coating are improved.

[0205] From the comparison of Examples 1-8 and Example 10, it can be seen that the active monomers include monofunctional acrylate monomers, difunctional acrylate monomers and multifunctional acrylate monomers, and the functionality of the multifunctional acrylate monomers is greater than or equal to 3, which can further improve the adhesion, shear strength, insulation performance, voltage resistance, high temperature resistance and aging performance of the insulating coating, so that the insulating coating has good mechanical properties, insulation performance, voltage resistance and high temperature resistance both before and after aging treatment.

[0206] From the comparison of Examples 1-8 and Example 9, it can be seen that controlling the mass ratio between the monofunctional acrylate monomers, the difunctional acrylate monomers and the multifunctional acrylate monomers within an appropriate range can further improve the adhesion, shear strength, high temperature resistance and aging performance of the insulating coating, so that the insulating coating has good mechanical properties and high temperature resistance both before and after aging treatment.

[0207] From the comparison of Examples 1-8 and Examples 11-12, it can be seen that controlling the mass percentage of active monomers in the photocurable ink within an appropriate range can further improve the adhesion, shear strength, insulation performance, voltage resistance, high temperature resistance and aging performance of the insulating coating, so that the insulating coating has good mechanical properties, insulation performance, voltage resistance and high temperature resistance both before and after aging treatment.

[0208] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, based on the ideas of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A light-curing ink, characterized in that: include: Acrylic resin and reactive monomer; The acrylic resin includes a polyester polyurethane acrylate resin and a bisphenol epoxy acrylate resin, and the mass ratio of the polyester polyurethane acrylate resin to the bisphenol epoxy acrylate resin is (3-6):

1.

2. The light-curable ink according to claim 1, characterized in that: The bisphenol epoxy acrylate resin includes one or more of bisphenol A epoxy acrylate resin, bisphenol S epoxy acrylate resin, and bisphenol F epoxy acrylate resin; and / or The mass percentage of the acrylic resin in the light-curable ink is 20%-40%; and / or The mass percentage of the active monomer in the photocurable ink is 50%-70%; and / or The mass ratio of the active monomer to the acrylic resin is (1.2-3.5):1; and / or The reactive monomers include monofunctional acrylate monomers, difunctional acrylate monomers and multifunctional acrylate monomers, and the functionality of the multifunctional acrylate monomers is greater than or equal to 3; and / or The molecular weight of the polyester polyurethane acrylate resin is 1000-1500; and / or The molecular weight of the bisphenol epoxy acrylate resin is 1000-1500; and / or The polyester polyurethane acrylate resin has the general structural formula shown in structural formula (1): and / or The bisphenol epoxy acrylate resin has a general structural formula shown in structural formula (2):

3. The light-curable ink according to claim 2, characterized in that: In the structural formula (1), R2, R5, and R6 are each independently selected from a C1-C6 alkyl group, and / or R4 is selected from a hexamethylene group or an isophorone group, and / or m is selected from an integer of 2-10; and / or In the structural formula (2), R1 is selected from hydrogen or C1-C6 alkyl, and / or n is selected from an integer of 2-10; and / or The mass ratio of the monofunctional acrylate monomer, the difunctional acrylate monomer and the multifunctional acrylate monomer is (4-6):1:(0.1-0.4); and / or The monofunctional acrylate monomer includes at least one of isobornyl acrylate, isodecyl acrylate, lauryl acrylate or hexadecyl acrylate; and / or The bifunctional acrylate monomer includes at least one of 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, and ethoxylated bisphenol A diacrylate; and / or The multifunctional acrylate monomer includes at least one of trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol penta / hexaacrylate, and tris(2-hydroxyethyl)isocyanurate triacrylate.

4. The light-curable ink according to any one of claims 1 to 3, characterized in that: The photocurable ink further includes an initiator, a pigment, an auxiliary agent and / or a diluent.

5. The light-curable ink according to claim 4, characterized in that: The initiator includes a deep curing initiator, a thioxanthone initiator and an amine initiator, and the absorption wavelength of the deep curing initiator is 300nm-400nm; and / or The auxiliary agents include wetting agents and adhesion agents; and / or The diluent includes at least one of isobornyl acrylate, isodecyl acrylate, lauryl acrylate or hexadecyl acrylate.

6. The light-curable ink according to claim 4, characterized in that: The mass percentage of the initiator in the photocurable ink is 2%-5%; and / or The mass percentage of the pigment in the light-curable ink is 0.5%-1%; and / or The mass percentage of the auxiliary agent in the light-curable ink is 1%-3%; and / or The mass percentage of the diluent in the light-curable ink is 4%-5%; and / or The particle size D50 of the pigment is ≤0.4 μm.

7. The light-curable ink according to claim 5, characterized in that: The deep curing initiator includes at least one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, bis(1-(2,4-difluorophenyl)-3-pyrrolyl)titanocene, bis-2,6-difluoro-3-pyrrolphenyltitanocene, 2-hydroxy-2-methyl-1-phenylacetone, and 1-hydroxycyclohexylphenyl ketone; and / or The thioxanthone initiator includes at least one of 2-chlorothioxanthone, isopropylthioxanthone and 2,4-diethylthioxanthone; and / or The amine initiator comprises at least one of an active amine and a tertiary amine benzoate; and / or The wetting agent comprises at least one of polyether-modified silicone and polyester-modified silicone; and / or The adhesive comprises at least one of phosphate-modified acrylate and silane-modified polymer; and / or The mass percentage of the deep curing initiator in the photocurable ink is 2%-5%; and / or The sum of the mass percentage of the thioxanthone initiator and the amine initiator in the photocurable ink is 1% to 3% by mass; and / or The mass ratio of the thioxanthone initiator to the amine initiator is 1:(0.2-0.5).

8. The light-curable ink according to claim 7, characterized in that: The active amine includes at least one of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexamethylenediamine, diethylamine, triethylamine, isophoronediamine, and 1,2-cyclohexanediamine; and / or The tertiary amine benzoate includes at least one of ethyl 4-(N,N-dimethylamino)benzoate, ethyl N,N-diphenylmethylcarboxylate, and 2-ethylhexyl N,N-dimethylbenzoate.

9. An insulating coating, characterized in that: The insulating coating is formed from the photocurable ink according to any one of claims 1 to 8.

10. A battery casing, characterized in that: include: Main body; An insulating coating layer is provided on at least a portion of the outer surface of the main body, and the insulating coating layer is formed by the photocurable ink according to any one of claims 1 to 8.

11. A method for preparing a battery shell, characterized in that: The preparation method of the battery shell includes: providing a main body portion of a battery housing; Using the light-curable ink according to any one of claims 1 to 8 as a raw material, spraying an ink layer on at least a portion of the outer surface of the main body; The ink layer is cured by ultraviolet light irradiation to form an insulating coating, thereby obtaining the battery shell.

12. The method for preparing a battery casing according to claim 11, wherein: The thickness of the ink layer is 50 μm-150 μm; and / or The light source of the ultraviolet light includes an electrodeless lamp, and / or the wavelength of the ultraviolet light is 200nm-450nm, and / or the curing time is 1s-10s.

13. A battery, characterized in that: The invention comprises the insulating coating according to claim 9, or comprises the battery shell according to claim 10, or is a battery shell prepared by the method according to claim 11 or 12.

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