UV-LED ink-jet printing insulation area edge coating ink for lithium ion battery positive plate and preparation method and application of UV-LED ink-jet printing insulation area edge coating ink

Abstract

The invention discloses UV-LED ink-jet printing insulation area edge coating ink for a lithium ion battery positive plate as well as a preparation method and an application of the UV-LED ink-jet printing insulation area edge coating ink. The ink comprises the following components in percentage by weight: 5-15% of modified epoxy resin, 10-20% of an organic solvent, 2-10% of tackifying resin, 1-5% of a flexibilizer, 5-10% of inorganic filler, 0.1-5% of a coupling agent, 40-360% of a monomer, 0.1-1% of a delayed thermal curing agent, 3-8% of a free radical photoinitiator, 1-3% of a cationic photoinitiator and 1-3% of other auxiliaries. The ink is used for UV curing ink-jet printing, a cured coating is solvent-resistant, electrochemical corrosion-resistant, high-voltage-resistant and good in insulativity and keeps good binding power with a lithium ion battery positive electrode current collector, a lithium ion battery edge-coated positive electrode piece obtained through ink-jet printing is efficient, high in quality and low in cost, and particularly, the lithium ion battery edge-coated positive electrode piece can be applied to a special-shaped battery. And the technical advantages are particularly remarkable.

Description

Technical Field

[0001] The present invention belongs to the technical field of lithium-ion batteries, and in particular relates to a UV-LED inkjet printing insulating area edge coating ink for lithium-ion battery positive electrode sheets, a preparation method and an application thereof. Background Art

[0002] With the development of lithium-ion battery technology, the market and technology have formed a severe competitive trend. Major battery manufacturers are particularly concerned about the yield rate of battery manufacturing, which has a great impact on battery manufacturing products and profits. The larger the size and capacity of the single cell, the more significant the impact of each technical detail of the fully automated manufacturing process on the yield rate of battery manufacturing. Among them, the edge coating process of the positive electrode insulation area to prevent the electrode from misaligning and short-circuiting is an important technical point.

[0003] The traditional process is to coat the insulating area of ​​the pole piece with a layer of aluminum oxide, and then cut it according to the battery requirements. This causes material loss and low efficiency. Especially for special-shaped batteries, the efficiency of traditional pole piece edge coating is low and even difficult to achieve.

[0004] Therefore, it is urgent to develop a UV-LED inkjet printing insulating area edge coating ink for lithium-ion battery positive electrode sheets, and use UV curing inkjet printing technology to produce insulating edge coated positive electrode sheets. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides an ink for UV-LED inkjet printing of insulating area edge coating of lithium ion battery positive electrode sheets. The ink is used for UV curing inkjet printing. The cured coating is resistant to solvents, electrochemical corrosion, high voltage, good insulation, and maintains good adhesion with the positive electrode collector of the lithium ion battery. The lithium ion battery edge-coated positive electrode sheet obtained by inkjet printing is efficient, high quality, and low cost, and its technical advantages are particularly significant, especially in special-shaped batteries.

[0006] Another object of the present invention is to provide a method for preparing the UV-LED inkjet printing insulating area edge coating ink for lithium ion battery positive electrode plates.

[0007] Another object of the present invention is to provide an application and use method of the UV-LED inkjet printing insulating area edge coating ink for lithium ion battery positive electrode plates.

[0008] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is as follows:

[0009] A UV-LED inkjet printing insulating area edge coating ink for lithium ion battery positive electrode sheets comprises the following components in weight percentage: 5-15% of modified epoxy resin, 10-20% of organic solvent, 2-10% of tackifying resin, 1-5% of toughening agent, 5-10% of inorganic filler, 0.1-5% of coupling agent, 40-60% of monomer, 0.1-1% of delayed type thermal curing agent, 3-8% of free radical photoinitiator, 1-3% of cationic photoinitiator and 1-3% of other auxiliary agents.

[0010] In some specific embodiments, the modified epoxy resin is an organosilicon-modified epoxy resin.

[0011] In some specific embodiments, the organic solvent is a strong polar solvent, preferably at least one of acetone, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, and N,N-dimethylpyrrolidone.

[0012] In some specific embodiments, the tackifying resin is a homopolymeric polyvinylidene fluoride or a modified acrylonitrile resin; preferably, a silicone-modified polyacrylonitrile resin with a molecular weight of more than 100,000 or a polyvinylidene fluoride with a molecular weight of 300,000.

[0013] In some specific embodiments, the toughening agent is a long-chain aliphatic compound containing a glycidyl ether group, preferably glycidyl methacrylate.

[0014] In some specific embodiments, the inorganic filler is selected from at least one of nano titanium dioxide, nano aluminum oxide, and nano silicon dioxide; preferably, the particle size D50 of the inorganic filler is less than 200 nanometers.

[0015] In some specific embodiments, the coupling agent is selected from at least one of the silane coupling agents KH507 and KH560.

[0016] In some specific embodiments, the monomer is any one of a monofunctional monomer, a difunctional monomer, and a trifunctional monomer;

[0017] Preferably, the monofunctional monomer is at least one selected from styrene, methyl (meth)acrylate, butyl (methyl)acrylate, and isooctyl (meth)acrylate;

[0018] The bifunctional monomer is selected from at least one of divinylbenzene, ethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, and tricyclodecane dimethanol diacrylate;

[0019] The trifunctional monomer is at least one selected from triallyl isocyanurate, ethoxylated trimethylolpropane triacrylate, and pentaerythritol triacrylate.

[0020] In some specific embodiments, the delayed thermal curing agent is an imidazole curing agent, preferably at least one selected from imidazole, methylimidazole, ethylimidazole, and phenylimidazole.

[0021] In some specific embodiments, the free radical photoinitiator is photoinitiator ITX.

[0022] In some specific embodiments, the cationic photoinitiator is Irgacure261.

[0023] In some specific embodiments, the other auxiliary agent is selected from at least one of a wetting agent, a dispersant, and a leveling agent, and preferably the main component of the auxiliary agent is a polyether-modified silicone or polyacrylate.

[0024] On the other hand, the aforementioned method for preparing UV-LED inkjet printing insulating area edge coating ink for lithium ion battery positive electrode sheet comprises the following steps:

[0025] (1) mixing the tackifying resin, the organic solvent, part of the monomer, the coupling agent, and the inorganic filler, grinding until the particle size D50 is less than 200 nm, filtering, and obtaining a milky white nano-dispersion slurry;

[0026] (2) dispersing the free radical photoinitiator and the cationic photoinitiator in the remaining monomers to obtain a mixed solution;

[0027] (3) The milky white nano-dispersion slurry obtained in step (1), the mixed solution obtained in step (2), the modified epoxy resin, the delayed-type thermal curing agent, the toughening agent, and the other additives are uniformly mixed, and then filtered to obtain UV-LED inkjet printing insulating area edge coating ink for lithium-ion battery positive electrode sheets.

[0028] On the other hand, the aforementioned UV-LED inkjet printed insulating area edge coating ink for lithium ion battery positive electrode sheets or the UV-LED inkjet printed insulating area edge coating ink for lithium ion battery positive electrode sheets prepared by the aforementioned preparation method is used in lithium ion batteries.

[0029] On the other hand, the aforementioned method for using UV-LED inkjet printing of insulating area edge ink for lithium-ion battery positive electrode sheet comprises the following steps:

[0030] (1) Loading the UV-LED inkjet printing insulating area edge coating ink for lithium ion battery positive electrode sheet into the printer, and printing the edge of the positive electrode sheet with a width of 1.5±0.2mm and a thickness of 10-15mm;

[0031] (2) irradiating the positive electrode sheet treated in step (1) under a UV-LED lamp for light curing;

[0032] (3) baking the positive electrode sheet treated in step (2) to allow the organic solvent to fully volatilize and dry the surface of the edge-coated rubber block in the insulating area;

[0033] (4) Further drying and thermally curing the surface-dried edge-coated electrode sheet to obtain an inkjet-printed insulating edge-coated positive electrode sheet.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The ink coated on the edge of the insulating area of ​​the UV-LED inkjet printed pole piece of the present invention has a fast curing speed, excellent adhesion, good flexibility, and the cured coating is resistant to solvents, electrochemical corrosion, high voltage, and has good insulation performance. DETAILED DESCRIPTION

[0036] The following examples further illustrate the technical solution of the present invention, but are not intended to limit the scope of protection of the present invention.

[0037] A UV-LED inkjet printing insulating area edge coating ink for lithium ion battery positive electrode sheet, comprising the following components by weight percentage:

[0038]

[0039] In the present invention, the modified epoxy resin is a silicone-modified epoxy resin; the added weight percentage of the modified epoxy resin is 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, etc., but is not limited thereto.

[0040] In the present invention, the organic solvent includes at least one of acetone, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, and N,N-dimethylpyrrolidone; the added weight percentage of the organic solvent is 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc., but is not limited thereto.

[0041] In the present invention, the tackifying resin is silicone-modified polyacrylonitrile with a molecular weight of more than 100,000 and polyvinylidene fluoride with a molecular weight of 300,000; the added weight percentage of the tackifying resin is 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc., but not limited to this.

[0042] In the present invention, the toughening agent is a long-chain aliphatic compound with a glycidyl ether group, such as glycidyl methacrylate; the weight percentage of the toughening agent added is 1%, 2%, 3%, 4%, 5%, etc., but is not limited thereto.

[0043] In the present invention, the inorganic filler includes at least one of nano titanium dioxide, nano aluminum oxide, and nano silicon dioxide, and the particle size D50 is less than 200 nanometers, such as 150nm, 100nm, etc.; the added weight percentage of the inorganic filler is 5%, 6%, 7%, 8%, 9%, 10%, etc., but is not limited thereto.

[0044] In the present invention, the coupling agent is at least one of silane coupling agents KH507 and KH560; the added weight percentage of the coupling agent is 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, etc., but is not limited thereto.

[0045] In the present invention, the monomer includes at least one of a monofunctional monomer, a bifunctional monomer, and a trifunctional monomer. The monofunctional monomer includes at least one of styrene, methyl (meth) acrylate, butyl (methyl) acrylate, and isooctyl (meth) acrylate; the bifunctional monomer includes at least one of divinylbenzene, ethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, and tricyclodecane dimethanol diacrylate; the trifunctional monomer includes at least one of triallyl isocyanurate, ethoxylated trimethylolpropane triacrylate, and pentaerythritol triacrylate. The added weight percentage of the monomer is 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58%, 60%, etc., but is not limited thereto.

[0046] In the present invention, the delayed-type thermal curing agent is an imidazole curing agent, for example, including at least one of imidazole, methylimidazole, ethylimidazole, and phenylimidazole; the added weight percentage of the delayed-type thermal curing agent is 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, etc., but is not limited to this.

[0047] In the present invention, the free radical photoinitiator is photoinitiator ITX, and the added weight percentage of the free radical photoinitiator is 3%, 4%, 5%, 6%, 7%, 8%, etc., but not limited thereto.

[0048] In the present invention, the cationic photoinitiator is Irgacure 261; the added weight percentage of the cationic photoinitiator is 1%, 1.5%, 2%, 2.5%, 3%, etc., but not limited thereto.

[0049] In the present invention, the other additives include at least one of a wetting agent, a dispersant, and a leveling agent, and their main components are polyether-modified silicones or polyacrylates; the weight percentage of the other additives added is 1%, 1.5%, 2%, 2.5%, 3%, etc., but not limited to this.

[0050] In another aspect of the present invention, the method for preparing the UV-LED inkjet printing insulating area edge coating ink for lithium ion battery positive electrode sheet comprises the following steps:

[0051] (1) mixing a tackifying resin, an organic solvent, 20-60% of a monomer, a coupling agent, and an inorganic powder, grinding the mixture to a particle size D50 of less than 200 nm, and filtering the mixture to obtain a milky white nano-dispersion slurry;

[0052] (2) dispersing a free radical photoinitiator and a cationic photoinitiator in the remaining monomers to obtain a mixed solution;

[0053] (3) The milky white nano-dispersion slurry obtained in step (1), the mixed solution obtained in step (2), the modified epoxy resin, the delayed-type thermal curing agent, the toughening agent, and other additives are uniformly mixed, and then filtered through a 200-mesh filter to obtain a UV-LED inkjet printing insulating area edge coating ink for lithium-ion battery positive electrode sheets.

[0054] In the present invention, the UV-LED inkjet printing insulating area edge coating ink for lithium ion battery positive electrode sheet can be used in the field of lithium ion battery technology, and the specific use method is exemplified as follows:

[0055] The method for using the UV-LED inkjet printing insulating area edge coating ink comprises the following steps:

[0056] (1) Load the UV-LED inkjet printing insulation area edge coating ink into the printer, and print the edge of the positive electrode sheet with a width of 1.5±0.2mm and a thickness of 10-15mm;

[0057] (2) irradiating the positive electrode sheet treated in step (1) under a UV-LED lamp for 5 seconds for light curing;

[0058] (3) baking the positive electrode sheet treated in step (2) in a forced air oven at 120° C. for 5 minutes to allow the organic solvent to fully evaporate and dry the surface of the coated rubber block in the insulating area;

[0059] (4) The edge-coated electrode sheet with dried surface is transferred into a vacuum drying oven at 85-120° C. and baked for 5-24 hours to further dry and heat cure to obtain an inkjet-printed insulating edge-coated positive electrode sheet.

[0060] The present invention is further explained below by more specific examples, but does not constitute any limitation.

[0061] Example 1

[0062] A UV-LED inkjet printing insulating area edge coating ink for lithium ion battery positive electrode sheet, comprising the following components by weight percentage:

[0063]

[0064]

[0065] The method for preparing the UV-LED inkjet printing insulating area edge coating ink for the positive electrode of a lithium-ion battery comprises the following steps:

[0066] (1) 3 g of PVDF with a molecular weight of 300,000 was dissolved in 20 g of tetrahydrofuran. After complete dissolution, 5 g of Al2O3, 3.5 g of silane coupling agent KH570, 15 g of isooctyl methacrylate, 5 g of 1,4-butanediol dimethacrylate, 5 g of ethoxylated trimethylolpropane triacrylate, 1 g of surfactant Digo 245, and 1 g of dispersant BYK 110 were added, and the mixture was dispersed at high speed and sand-milled to form a uniform milky white dispersion slurry;

[0067] (2) 3 g of free radical photoinitiator ITX, 1 g of cationic photoinitiator Irgacure261, 0.5 g of phenylimidazole, and 20 g of isooctyl methacrylate were mixed to obtain a mixed solution;

[0068] (3) The milky white slurry obtained in step (1), the mixed solution obtained in step (2), 14 g of silicone-modified epoxy resin, and 3 g of methyl methacrylate glycidyl ether are mixed evenly, and then filtered through a 200-mesh filter membrane to obtain UV-LED inkjet printing insulating area edge coating ink for lithium-ion battery positive electrode sheets.

[0069] The method for using the UV-LED inkjet printing insulating area edge coating ink comprises the following steps:

[0070] (1) Load the UV-LED inkjet printing insulation area edge coating ink into the printer, and print the edge of the positive electrode sheet with a width of 1.5±0.2mm and a thickness of 10-15mm;

[0071] (2) irradiating the positive electrode sheet treated in step (1) under a UV-LED lamp for 5 seconds for light curing;

[0072] (3) baking the positive electrode sheet treated in step (2) in a forced air oven at 120° C. for 5 minutes to allow the solvent tetrahydrofuran to fully evaporate and dry the surface of the coated rubber block in the insulating area;

[0073] (4) The surface-dried edge-coated electrode sheet is transferred into a 120° C. vacuum drying oven and baked for 5 h to further dry and thermally cure to obtain an inkjet-printed insulating edge-coated positive electrode sheet.

[0074] Example 2

[0075] A UV-LED inkjet printing insulating area edge coating ink for lithium ion battery positive electrode sheet, comprising the following components by weight percentage:

[0076]

[0077]

[0078] The method for preparing the UV-LED inkjet printing insulating area edge coating ink for the positive electrode of a lithium-ion battery comprises the following steps:

[0079] (1) 3 g of PVDF with a molecular weight of 300,000 was dissolved in 20 g of N,N-dimethylpyrrolidone. After complete dissolution, 8 g of TiO2, 2.5 g of silane coupling agent KH560, 10 g of butyl methacrylate, 4 g of divinylbenzene, 5 g of pentaerythritol triacrylate, 1 g of dispersant BYK 110, and 1 g of dispersant BYK 161 were added, and the mixture was dispersed at high speed and sand-milled to form a uniform milky white dispersion slurry;

[0080] (2) 3 g of free radical photoinitiator ITX, 2 g of cationic photoinitiator Irgacure261, 0.5 g of imidazole, and 35 g of butyl methacrylate were mixed to obtain a mixed solution;

[0081] (3) The white dispersion obtained in step (1), the mixed solution obtained in step (2), 10 g of silicone-modified epoxy resin, and 5 g of methyl methacrylate are mixed evenly, and then filtered through a 200-mesh filter membrane to obtain UV-LED inkjet printing insulating area edge coating ink for lithium-ion battery positive electrode sheets.

[0082] The method for using the UV-LED inkjet printing insulating area edge coating ink comprises the following steps:

[0083] (1) Load the UV-LED inkjet printing insulation area edge coating ink into the printer, and print the edge of the positive electrode sheet with a width of 1.5±0.2mm and a thickness of 10-15mm;

[0084] (2) irradiating the positive electrode sheet treated in step (1) under a UV-LED lamp for 5 seconds for light curing;

[0085] (3) baking the positive electrode sheet treated in step (2) in a forced air oven at 120° C. for 5 minutes to allow the solvent tetrahydrofuran to fully evaporate and dry the surface of the coated rubber block in the insulating area;

[0086] (4) The surface-dried edge-coated electrode sheet was transferred into a 95° C. vacuum drying oven and baked for 10 h to further dry and thermally cure to obtain an inkjet-printed insulating edge-coated positive electrode sheet.

[0087] Example 3

[0088] A UV-LED inkjet printing insulating area edge coating ink for lithium ion battery positive electrode sheet, comprising the following components by weight percentage:

[0089]

[0090]

[0091] The method for preparing the UV-LED inkjet printing insulating area edge coating ink for the positive electrode of a lithium-ion battery comprises the following steps:

[0092] (1) 2 g of organosilicon-modified polyacrylonitrile with a molecular weight of 100,000 was dissolved in 20 g of N,N-dimethylformamide. After complete dissolution, 10 g of SiO2, 1.5 g of silane coupling agent KH560, 15 g of butyl methacrylate, 4 g of divinylbenzene, 5 g of pentaerythritol triacrylate, 1 g of dispersant BYK 161, and 1 g of Lubrizol 32500 were added, and the mixture was dispersed at high speed and sand-milled to form a uniform milky white dispersion slurry;

[0093] (2) 3 g of free radical photoinitiator ITX, 2 g of cationic photoinitiator Irgacure261, 0.5 g of vinyl imidazole, 15 g of isooctyl methacrylate, and 5 g of styrene were mixed to obtain a mixed solution;

[0094] (3) The white dispersion obtained in step (1), the mixed solution obtained in step (2), 10 g of silicone-modified epoxy resin, and 5 g of methyl methacrylate are mixed evenly, and then filtered through a 200-mesh filter membrane to obtain UV-LED inkjet printing insulating area edge coating ink for lithium-ion battery positive electrode sheets.

[0095] The method for using the UV-LED inkjet printing insulating area edge coating ink comprises the following steps:

[0096] (1) Load the UV-LED inkjet printing insulation area edge coating ink into the printer, and print the edge of the positive electrode sheet with a width of 1.5±0.2mm and a thickness of 10-15mm;

[0097] (2) irradiating the positive electrode sheet treated in step (1) under a UV-LED lamp for 5 seconds for light curing;

[0098] (3) baking the positive electrode sheet treated in step (2) in a forced air oven at 120° C. for 5 minutes to allow the solvent N,N-dimethylformamide to fully evaporate and dry the surface of the coated rubber block in the insulating area;

[0099] (4) The surface-dried edge-coated electrode sheet is transferred into a 100° C. vacuum drying oven and baked for 8 h to further dry and thermally cure to obtain an inkjet-printed insulating edge-coated positive electrode sheet.

[0100] The basic properties of the UV-LED inkjet printed insulating area edge coating ink obtained in Examples 1-3 and the mechanical properties test after printing and curing on the current collector aluminum foil:

[0101] Comparative Example 1:

[0102] 80g of aluminum oxide powder with a particle size of D50 = 0.3-0.7μm was dispersed in 200g of N,N-dimethylpyrrolidone solvent, and 20g of PVDF with a molecular weight of 500,000 was added at the same time. The mixture was stirred to allow the PVDF to fully dissolve, and a coating solution in which PVDF and ceramics were evenly mixed was obtained. The coating was applied on the edge of the positive electrode sheet using a slit coating process, and the coating thickness was controlled at 30±2μm. The solution was dried at 120°C to achieve PVDF / Al2O3 edge coating in the insulating area.

[0103] Comparative Example 2:

[0104] 100g of aluminum oxide powder with a particle size of D50=0.3-0.7μm was dispersed in 200g of N,N-dimethylpyrrolidone solvent, and 10g of PVDF with a molecular weight of 500,000 was added at the same time. The mixture was stirred to allow the PVDF to fully dissolve, and a coating solution in which PVDF and ceramic were evenly mixed was obtained. The coating was applied on the edge of the positive electrode sheet using a slit coating process, and the coating thickness was controlled at 30±2μm. The solution was dried at 120°C to achieve PVDF / Al2O3 edge coating in the insulating area.

[0105] <Performance Test Method>

[0106] Viscosity test: Use BROOKFIELD DV-II+Pro rotational viscometer to test the ink viscosity at 25°C;

[0107] Average particle size: Zeta potential analyzer is used to test the nanoparticle size distribution of the color paste;

[0108] Surface tension: Use a surface tension meter to test the surface tension of the ink;

[0109] Adhesion test before and after electrolyte solvent immersion:

[0110] Before soaking: After high temperature curing, stick 3M600# tape on the touch-coated sample strip, tightly and without bubbles, pull it up quickly, and observe the falling of characters;

[0111] After immersion: electrolyte solvent (PC:DMC:EMC molar ratio = 1:1:1), 60°C, immerse for 24 hours, observe whether there is obvious shedding;

[0112] Bending test: Use a folding tester to bend the aluminum foil after curing the characters 10 times to observe the breakage of the characters;

[0113] Hi-pot test: using an AC withstand voltage tester, the inkjet printed and cured specimens on the aluminum foil current collector are tested. The test voltage range is: AC 0-5KV (±3%), time 1-99 seconds; test current: 0-200MA (±3%).

[0114] <Test Results>

[0115]

[0116] It can be seen from the above table that the UV-LED inkjet-printed insulating area edge-coated ink for lithium-ion battery positive electrode sheets obtained in Examples 1-3 has low viscosity, small particle size, and appropriate surface tension, which can ensure smooth ink spraying. The printing and curing on the current collector aluminum foil has excellent effect, strong adhesion, resistance to electrolyte solvents, and can reach a breakdown voltage of 1500V, with good insulation; it has extremely strong bending resistance and good flexibility. The two comparative examples 1-2 using traditional processes for slit coating have a coating thickness of 30μm, and their breakdown voltage just meets the insulation requirement of greater than 800V, and their bending resistance is poorer than that of inkjet-printed coatings. The above results show that the UV-LED inkjet-printed insulating area edge-coated ink of the present invention has excellent performance and can be effectively used for edge-coating printing of insulating areas of lithium battery positive electrode sheets.

[0117] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A UV-LED inkjet printing insulating area edge coating ink for lithium ion battery positive electrode sheet, characterized in that: The invention comprises the following components in percentage by weight: 5-15% of modified epoxy resin, 10-20% of organic solvent, 2-10% of tackifying resin, 1-5% of toughening agent, 5-10% of inorganic filler, 0.1-5% of coupling agent, 40-60% of monomer, 0.1-1% of delayed thermal curing agent, 3-8% of free radical photoinitiator, 1-3% of cationic photoinitiator and 1-3% of other auxiliary agents.

2. The UV-LED inkjet printing insulating area edge coating ink as claimed in claim 1, characterized in that: The modified epoxy resin is an epoxy resin modified by silicone.

3. The UV-LED inkjet printing insulating area edge coating ink as claimed in claim 1, characterized in that: The organic solvent is a strong polar solvent, preferably at least one of acetone, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide and N,N-dimethylpyrrolidone.

4. The UV-LED inkjet printing insulating area edge coating ink as claimed in claim 1, characterized in that: The tackifying resin is a homopolymerized polyvinylidene fluoride or a modified acrylonitrile resin; preferably a silicone-modified polyacrylonitrile resin with a molecular weight of more than 100,000 or a polyvinylidene fluoride with a molecular weight of 300,000; and / or The toughening agent is a long-chain aliphatic compound containing a glycidyl ether group, preferably glycidyl methacrylate.

5. The UV-LED inkjet printing insulating area edge coating ink as claimed in claim 1, characterized in that: The inorganic filler is selected from at least one of nano titanium dioxide, nano aluminum oxide, and nano silicon dioxide; preferably, the particle size D50 of the inorganic filler is less than 200 nanometers; and / or The coupling agent is selected from at least one of silane coupling agents KH507 and KH560.

6. The UV-LED inkjet printing insulating area edge coating ink as claimed in claim 1, characterized in that: The monomer is any one of a monofunctional monomer, a difunctional monomer, and a trifunctional monomer; Preferably, the monofunctional monomer is selected from at least one of styrene, methyl (meth)acrylate, butyl (methyl)acrylate, and isooctyl (meth)acrylate; and / or The bifunctional monomer is at least one selected from divinylbenzene, ethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, tricyclodecane dimethanol diacrylate; and / or The trifunctional monomer is at least one selected from triallyl isocyanurate, ethoxylated trimethylolpropane triacrylate, and pentaerythritol triacrylate.

7. The UV-LED inkjet printing insulating area edge coating ink as claimed in claim 1, characterized in that: The delayed thermal curing agent is an imidazole curing agent, preferably at least one selected from imidazole, methylimidazole, ethylimidazole, and phenylimidazole; and / or The free radical photoinitiator is photoinitiator ITX; and / or The cationic photoinitiator is Irgacure 261; and / or The other auxiliary agent is selected from at least one of a wetting agent, a dispersant, and a leveling agent, and preferably the main component of the auxiliary agent is a polyether-modified silicone or polyacrylate.

8. The method for preparing the UV-LED inkjet printing insulating area edge coating ink for lithium ion battery positive electrode sheet according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) mixing the tackifying resin, the organic solvent, part of the monomer, the coupling agent, and the inorganic filler, grinding until the particle size D50 is less than 200 nm, filtering, and obtaining a milky white nano-dispersion slurry; (2) dispersing the free radical photoinitiator and the cationic photoinitiator in the remaining monomers to obtain a mixed solution; (3) The milky white nano-dispersion slurry obtained in step (1), the mixed solution obtained in step (2), the modified epoxy resin, the delayed-type thermal curing agent, the toughening agent, and the other additives are uniformly mixed, and then filtered to obtain UV-LED inkjet printing insulating area edge coating ink for lithium-ion battery positive electrode sheets.

9. Use of the UV-LED inkjet printing insulating area edge coating ink for lithium ion battery positive electrode sheets as described in any one of claims 1 to 7 or the UV-LED inkjet printing insulating area edge coating ink for lithium ion battery positive electrode sheets prepared by the preparation method according to claim 8 in lithium ion batteries.

10. The method for using the UV-LED inkjet printing insulating area edge coating ink for lithium ion battery positive electrode sheets according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Loading the UV-LED inkjet printing insulating area edge coating ink for lithium ion battery positive electrode sheet into the printer, and printing the edge of the positive electrode sheet with a width of 1.5±0.2mm and a thickness of 10-15mm; (2) irradiating the positive electrode sheet treated in step (1) under a UV-LED lamp for light curing; (3) baking the positive electrode sheet treated in step (2) to allow the organic solvent to fully volatilize and dry the surface of the edge-coated rubber block in the insulating area; (4) Further drying and thermally curing the surface-dried edge-coated electrode sheet to obtain an inkjet-printed insulating edge-coated positive electrode sheet.

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