Acrylate polymer, dispersant, preparation method, electrode slurry, electrode pole piece, and battery

Abstract

The present invention relates to an acrylate polymer, a dispersant, a preparation method, an electrode slurry, an electrode pole piece, and a battery. The acrylate polymer comprises a repeat unit I, a repeat unit II, and a repeat unit III; based on the total mass of the acrylate polymer, the mass percentage of the repeat unit I is 30.0% -70.0%, and the mass percentage of the repeat unit III is 20.0%-60.0%. The preparation method is simple. Further, when the dispersant containing the acrylate polymer is used in the electrode slurry, the dispersion viscosity reduction and viscosity stabilization effects are excellent, further improving the mass stability of the battery.

Description

Acrylate polymer, dispersant, preparation method, electrode slurry, electrode plate and battery

[0001] This application claims priority to Chinese Patent Application No. 2023118095221, filed December 26, 2023. This application incorporates the entirety of the aforementioned Chinese Patent Application. Technical Field

[0002] The invention relates to an acrylate polymer, a dispersant, a preparation method, an electrode slurry, an electrode plate and a battery. Background Art

[0003] In recent years, with the development of new energy storage and electric vehicle technologies, carbon materials such as carbon nanotubes, graphene, and conductive carbon black, as well as carbon-coated materials such as lithium iron phosphate and lithium iron manganese phosphate, have been widely used as electrode materials. However, due to the unique particle structure and surface morphology of these carbon materials and carbon-coated materials, the preparation of electrode slurries without dispersants or with traditional polyvinyl pyrrolidone dispersants often results in poor particle dispersion, high slurry viscosity, and short storage life. This can render the slurry unusable or require further processing before use, further impacting battery quality and stability.

[0004] Patent application CN115975104A discloses an acrylate comb dispersant and its preparation method. This method involves polymerizing acrylate monomers, methacrylate monomers, unsaturated acids, and unsaturated amide monomers in the presence of an initiator and a chain transfer agent to produce the acrylate comb dispersant. The dispersant exhibits excellent dispersion properties for battery cathode materials. However, if the unsaturated amide monomer content in the copolymer is too low, it has no beneficial effect on dispersion performance. However, if the unsaturated amide monomer content is too high, the resistance of the battery cathode plate decreases and its flexibility decreases.

[0005] Patent application CN 116390976 A discloses a dispersant composition consisting of an alcoholamine compound, an acrylic polymer, and a solvent, which effectively disperses carbon-based conductive materials. However, the polyether acrylate structure contained in the acrylic polymer degrades under the action of the alcoholamine compound during storage and use, resulting in a loss of dispersibility and insufficient stability.

[0006] Summary of the Invention

[0007] The present invention overcomes the problems often encountered in the prior art in preparing electrode slurries, such as poor particle dispersion, high slurry viscosity, and poor storage stability. The invention provides an acrylate polymer, a dispersant, a preparation method, an electrode slurry, an electrode plate, and a battery. The preparation method is simple, and the resulting acrylate polymer has a novel structure. The dispersant containing the acrylate polymer can be used in the preparation of electrode slurries, exhibiting excellent dispersing, viscosity reduction, and viscosity stabilization effects, further improving battery quality and stability.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides an acrylate polymer comprising a repeating unit I, a repeating unit II, and a repeating unit III; based on the total mass of the acrylate polymer, the mass percentage of the repeating unit I is 30.0%-70.0%; the mass percentage of the repeating unit III is 20.0%-60.0%;

[0010] The structure of the repeating unit I is shown in formula (I):

[0011] In each repeating unit I,

[0012] R1 is each independently hydrogen or methyl;

[0013] R2 is each independently C 10 -C 25 Alkyl;

[0014] The structure of the repeating unit II is shown in formula (II):

[0015] In each repeating unit II,

[0016] R3 are each independently hydrogen or methyl;

[0017] Z is independently hydrogen, Li + 、Na + , K + NH4 + or an organic amine group with a molecular weight of less than 150;

[0018] The structure of the repeating unit III is shown in formula (III):

[0019] In each repeating unit III,

[0020] R4 are each independently hydrogen or methyl;

[0021] Each A group is independently -(CH2) p1 -;

[0022] In each A group, p1 is independently 0-2;

[0023] The B groups are each independently

[0024] In each B group, R5 is independently hydrogen or methyl, and R6 is independently hydrogen, C1-C 18 alkyl or C2-C6 acyl, and n1 is independently 4-70.

[0025] In the present invention, “in each ..., ... are each independently ...” means that in the molecular chain of the acrylic ester polymer, in different repeating units represented by the same general formula, the groups represented by the same symbol may be the same or different.

[0026] For example, "In each repeating unit I, R1 is independently hydrogen or methyl" means that in the molecular chain of the acrylate polymer, R1 in different repeating units I represented by formula (I) may be the same or different. Similarly, each repeating unit II and each repeating unit III has the same meaning.

[0027] For another example, it is necessary to explain that "in each B group, R5 is independently hydrogen or methyl, R6 is independently hydrogen, C1-C 18 The meaning of "n1 is 4-70" is that in the molecular chain of the acrylate polymer, in different repeating units I represented by formula (I), "n1" in each B group may be the same or different; n1 In the example, R5 may be the same or different.

[0028] In the present invention, in the acrylic ester polymer, the repeating unit I, the repeating unit II and the repeating unit III may be randomly distributed.

[0029] In the present invention, the weight average molecular weight of the acrylic ester polymer may be 10,000-70,000, preferably 28,100-68,300, more preferably 36,200-52,800, for example, 28,100, 36,200, 49,600, 52,800 or 68,300.

[0030] In the present invention, the molecular weight distribution index (PDI) of the acrylic ester polymer may be no greater than 2.20, preferably 1.65-2.15, more preferably 1.65-1.92, for example 1.65, 1.75, 1.85, 1.92 or 2.15.

[0031] In the present invention, in each repeating unit I, R2 is independently C12 -C 25 Alkyl, preferably C 16 -C 22 Alkyl groups, such as C 18 of alkyl.

[0032] In certain specific embodiments, in each repeating unit I, R1 is methyl; R2 is C 12 of alkyl.

[0033] In certain specific embodiments, in each repeating unit I, R1 is hydrogen; R2 is C 18 of alkyl.

[0034] In certain specific embodiments, in each repeating unit I, R1 is hydrogen; R2 is C 22 of alkyl.

[0035] In certain specific embodiments, in each repeating unit I, R1 is hydrogen; R2 is C 16 of alkyl.

[0036] In the present invention, the mass percentage of the repeating unit I may be 30.0%-65.0%, preferably 40.0%-65.0%, for example 30.0%, 40.0%, 50.0%, 60.0% or 65.0%.

[0037] In the present invention, in each repeating unit II, Z is preferably hydrogen.

[0038] In the present invention, p1 in each A group is independently 0 or 1.

[0039] In the present invention, in each B group, R6 is independently a methyl group, a butyl group or an acetyl group.

[0040] In the present invention, in each B group, n1 may be 6-45, for example, 6, 9, 16, 20 or 45.

[0041] In certain specific embodiments, in each repeating unit II, R4 and R5 are both hydrogen; R6 is methyl; and p1 is 1.

[0042] In certain specific embodiments, in each repeating unit II, R4 and R5 are both hydrogen; R6 is methyl; and p1 is 0.

[0043] In certain specific embodiments, in each repeating unit II, R4 is hydrogen; R5 is methyl; R6 is butyl; and p1 is 1.

[0044] In certain specific embodiments, in each repeating unit II, R4 is hydrogen; R5 is hydrogen or methyl; R6 is acetyl; and p1 is 1.

[0045] In certain specific embodiments, in each repeating unit II, R4 is methyl; R5 is hydrogen; R6 is acetyl; and p1 is 1.

[0046] In the present invention, the mass percentage of the repeating unit II may be 5.0%-20.0%, preferably 10.0%-15.0%, for example 5.0%, 10.0%, 15.0% or 20.0%.

[0047] In the present invention, the mass percentage of the repeating unit III may be 20.0%-50.0%, for example, 20.0%, 30.0%, 40.0% or 50.0%.

[0048] In the present invention, the acrylic ester polymer may further include a repeating unit IV, wherein the repeating unit IV is a repeating unit corresponding to styrene, and the mass percentage of the repeating unit IV may be 5.0%-20.0%.

[0049] In the present invention, the acrylic ester polymer may not include repeating units containing an amine group.

[0050] In the present invention, the acrylic ester polymer may be any one of A-1 to A-5:

[0051] A-1: In the repeating unit I, R1 is methyl, R2 is C 12 alkyl; in repeating unit II, R3 is hydrogen, Z is hydrogen; in repeating unit III, R4 is hydrogen, p1=1, R5 is hydrogen, and R6 is methyl; the mass percentage of repeating unit I is 65.0%, the mass percentage of repeating unit II is 15.0%, and the mass percentage of repeating unit III is 20.0%, excluding repeating units containing amino groups;

[0052] A-2: In repeating unit I, R1 is hydrogen, R2 is C 18 alkyl; in repeating unit II, R3 is hydrogen, Z is hydrogen; in repeating unit III, R4 is hydrogen, p1=0, R5 is hydrogen, and R6 is methyl; the mass percentage of repeating unit I is 40.0%, the mass percentage of repeating unit II is 10.0%, and the mass percentage of repeating unit III is 50.0%, excluding repeating units containing amino groups;

[0053] A-3: In repeating unit I, R1 is hydrogen, R2 is C 22 alkyl; in repeating unit II, R3 is methyl, Z is hydrogen; in repeating unit III, R4 is hydrogen, p1=1, R5 is methyl, and R6 is butyl; the mass percentage of repeating unit I is 30.0%, the mass percentage of repeating unit II is 20.0%, and the mass percentage of repeating unit III is 50.0%, excluding repeating units containing amino groups;

[0054] A-4: The acrylic ester polymer also includes repeating unit IV, which corresponds to the repeating unit of styrene; in repeating unit I, R1 is hydrogen, R2 is C 16 alkyl; in repeating unit II, R3 is hydrogen, Z is hydrogen; in repeating unit III, R4 is hydrogen, p1=1, in each B group, R5 is hydrogen or methyl, and R6 is acetyl; the mass percentage of repeating unit I is 60.0%, the mass percentage of repeating unit II is 5.0%, the mass percentage of repeating unit III is 30.0%, and the mass percentage of repeating unit IV may be 5.0%, excluding repeating units containing amino groups;

[0055] A-5: In each repeating unit I, R1 is hydrogen or methyl, R2 is C 12 Alkyl or C 18 alkyl; in the repeating unit II, R3 is hydrogen, Z is hydrogen; in the repeating unit III, R4 is a methyl group, p1=1, R5 is hydrogen, and R6 is an acetyl group; the mass percentage of the repeating unit I is 50.0%, the mass percentage of the repeating unit II is 10.0%, and the mass percentage of the repeating unit III is 40.0%, excluding the repeating unit containing an amino group.

[0056] In the present invention, the carbon nanotube-containing electrode slurry prepared from the acrylic ester polymer has a rotational viscosity of 182 mPa·s after storage for 1 hour and a rotational viscosity of 620 mPa·s after storage for 28 days under the viscosity test method of GB / T10247-2008.

[0057] In the present invention, the carbon-coated lithium iron phosphate electrode slurry prepared from the acrylic polymer has a rotational viscosity of 8700 mPa·s after storage for 1 hour and a rotational viscosity of 12600 mPa·s after storage for 24 hours under the viscosity test method of GB / T 10247-2008.

[0058] In the present invention, the acrylic ester polymer described herein is known to those skilled in the art to inevitably include some residual impurities in the preparation process, such as initiators, chain transfer agents, etc., due to some auxiliary materials used in the preparation process.

[0059] In a second aspect, the present invention provides a method for preparing an acrylate polymer, comprising the following steps: subjecting raw materials to a free radical polymerization reaction to obtain an acrylate polymer; wherein the raw materials include polymerizable monomers, and the polymerizable monomers include monomer M-1, monomer M-2, and monomer M-3; based on the total mass of the polymerizable monomers, the mass percentage of the monomer M-1 is 30.0%-70.0%; the mass percentage of the monomer M-3 is 20.0%-60.0%;

[0060] The structure of the monomer M-1 is shown in formula M-1:

[0061] wherein R1 and R2 are as described above;

[0062] The structure of the monomer M-2 is shown in formula M-2:

[0063] wherein R3 and Z are as described above;

[0064] The structure of the monomer M-3 is shown in formula M-3:

[0065] wherein A, B and R4 are as described above.

[0066] In the present invention, the monomer M-1 may be one or more of lauryl methacrylate, stearyl acrylate, behenyl acrylate and hexadecyl acrylate.

[0067] In the present invention, the mass percentage of the monomer M-1 may be 30.0%-65.0%, preferably 40.0%-65.0%, for example 30.0%, 40.0%, 50.0%, 60.0% or 65.0%.

[0068] In the present invention, the monomer M-2 may be acrylic acid or methacrylic acid.

[0069] In the present invention, the mass percentage of the monomer M-2 may be 2.0%-20.0%, preferably 10.0%-15.0%, for example 5.0%, 10.0%, 15.0% or 20.0%.

[0070] In the present invention, the monomer M-3 may be polyethylene glycol allyl methyl ether, polyethylene glycol vinyl methyl ether, polypropylene glycol allyl butyl ether, allyl polyethylene glycol polypropylene glycol acetate or methallyl polyethylene glycol acetate.

[0071] In the present invention, the average degree of polymerization of the polyol in the monomer M-3 may be 6-45, for example, 6, 9, 16, 20 or 45.

[0072] In the present invention, the mass percentage of the monomer M-3 may be 20.0%-50.0%, for example, 20.0%, 30.0%, 40.0% or 50.0%.

[0073] In the present invention, the sum of the mass percentages of the monomer M-1, the monomer M-2 and the monomer M-3 may be 90.0%-100.0%, preferably 95.0%-100.0%, for example 95.0% or 100.0%.

[0074] In the present invention, the polymerizable monomers may further include monomer M-4.

[0075] The monomer M-4 may be styrene, and the mass percentage of the monomer M-4 may be 5.0%-20.0%.

[0076] In the present invention, the polymerizable monomers may not include monomers containing amino groups. The additional addition of amino groups will not bring any beneficial effects and will increase the rigidity of the polymer chain segments.

[0077] In the preparation method of the present invention, the reaction operation and conditions can be carried out according to conventional operations and conditions of this type of reaction in the art.

[0078] In the present invention, the free radical polymerization reaction can be carried out in a solvent.

[0079] The solvent can be any organic solvent suitable in the art, preferably one or more of ethyl acetate, butyl acetate, propylene glycol methyl ether acetate, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone, such as propylene glycol methyl ether acetate, N,N-dimethylformamide, butyl acetate or N-methylpyrrolidone.

[0080] In the present invention, the raw materials further include an initiator and a chain transfer agent.

[0081] The initiator may be a peroxide initiator, an azo initiator, or a redox initiator composed of a peroxide initiator and a reducing agent.

[0082] The peroxide initiator can be dibenzoyl peroxide, dilauroyl peroxide, diisopropyl benzene peroxide, isopropyl benzene hydroperoxide, methyl ethyl ketone peroxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, tert-butyl peroxytivalate, tert-butyl peroxypivalate, tert-butyl peroxyisobutyrate, tert-butyl peroxy(2-ethylhexanoate), 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl isopropyl benzene peroxide or 1,4-bis-tert-butyl peroxyisopropyl benzene.

[0083] The azo initiator can be azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, 1,1'-azo(cyanocyclohexane), 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), azobisimidazolinylpropane, 2,2'-azobis(N-butyl 2-methylpropionamide), 2,2'-azo(2-methyl-N-(2-hydroxyethyl)propionamide), 2,2-azobisisobutylamidine dihydrochloride or 2,2'-azabis(2-imidazoline) dihydrochloride.

[0084] The reducing agent may be an amine compound, preferably tetramethylethylenediamine, N,N-dimethylaniline, N,N-dimethyl-p-toluidine, ethylenediamine, diethylenetriamine, triethylenetetramine or tetraethylenepentamine.

[0085] The initiator can be added dropwise into the reaction system in the form of an initiator solution. The solvent of the initiator solution is the same as the aforementioned solvent. The addition time can be 360-420 minutes.

[0086] The chain transfer agent may be one or more of a mercaptocarboxylic acid chain transfer agent, a thiol chain transfer agent, isopropyl alcohol and hypophosphorous acid.

[0087] The mercaptocarboxylic acid chain transfer agent may be mercaptoacetic acid, 3-mercaptopropionic acid, ethyl 3-mercaptopropionate, butyl 3-mercaptopropionate, octyl 3-mercaptopropionate or trimethylolpropane tris(3-mercaptopropionate).

[0088] The mercaptan chain transfer agent may be mercaptoethanol, butyl mercaptan, hexyl mercaptan, octyl mercaptan or dodecyl mercaptan.

[0089] The chain transfer agent can be added dropwise into the reaction system in the form of a monomer solution. The monomer solution can include the polymerizable monomers and the chain transfer agent. The solvent of the monomer solution is the same as that described above. The addition time can be 360-420 minutes.

[0090] In the present invention, the reaction temperature of the free radical polymerization reaction can be 60-95°C, for example, 60°C, 65°C, 70°C, 78°C, 82°C, 90°C or 95°C.

[0091] In certain specific embodiments, the reaction temperature of the free radical polymerization reaction is 78-82°C.

[0092] In certain specific embodiments, the reaction temperature of the free radical polymerization reaction is 65-70°C.

[0093] In certain specific embodiments, the reaction temperature of the free radical polymerization reaction is 90-95°C.

[0094] In certain embodiments, the reaction temperature of the free radical polymerization reaction is 60-65°C.

[0095] In the present invention, the reaction time of the free radical polymerization reaction can be 30-120 min, for example, 30 min, 60 min or 120 min.

[0096] In the present invention, the free radical polymerization reaction can be carried out under a protective atmosphere. The protective atmosphere refers to a gas atmosphere that does not react with the reaction system, such as nitrogen or an inert gas.

[0097] In a third aspect, the present invention provides an acrylate polymer, which is prepared using the above-mentioned method for preparing an acrylate polymer.

[0098] In a fourth aspect, the present invention provides a dispersant comprising the above-mentioned acrylate polymer, a volatile small molecule amine compound and the solvent;

[0099] Wherein, the mass ratio of the acrylic ester polymer to the volatile small molecule amine compound is 100:(1-100).

[0100] In the present invention, the volatile small molecule amine compound can be selected from conventional sources in the art, preferably one or more of triethylamine, tri-n-butylamine, ethylenediamine, butanediamine, hexamethylenediamine, monoethanolamine, monoisopropanolamine, n-propanolamine, N,N-dimethylethanolamine, 2-amino-2-methyl-1-propanol, hydroxyethylethylenediamine and hydroxyethylhydrazine, such as butanediamine, monoethanolamine, n-propanolamine, N,N-dimethylethanolamine or 2-amino-2-methyl-1-propanol.

[0101] In the present invention, the mass ratio of the acrylic acid ester polymer to the volatile small molecule amine compound can be 100:1, 100:5, 100:10, 100:29.9 or 100:89.7.

[0102] In the present invention, the mass ratio of the acrylate polymer to the solvent can be 100:(50-5000), preferably 100:(100-1000), for example, 100:139.9, 100:140, 100:140.1, 100:310.3, 100:370.1, 100:395.0, 100:399.0 or 100:890.

[0103] In the present invention, the preparation method of the dispersant comprises the following steps: mixing the acrylic ester polymer, the volatile small molecule amine compound and the solvent.

[0104] In a fifth aspect, the present invention provides an electrode slurry comprising an electrode material and the dispersant as described above.

[0105] In the present invention, the electrode material may be a carbon material or a carbon-coated material.

[0106] The carbon material may be selected from conventional materials in the art, such as one or more of carbon nanotubes, graphene, acetylene black, porous carbon and conductive carbon black.

[0107] The carbon-coated material may be selected from conventional materials in the art, such as one or both of carbon-coated lithium iron phosphate and carbon-coated lithium manganese iron phosphate.

[0108] The electrode slurry may include the dispersant, the carbon material, and the solvent. The mass ratio of the acrylate dispersant to the carbon material may be 12.5:(5.0-20.0), such as 12.5:5.0, 12.5:10.0, or 12.5:20.0.

[0109] The electrode slurry may include: the dispersant, the carbon coating material, a binder, a conductive agent, and the solvent. The mass ratio of the dispersant, the carbon coating material, the binder, and the conductive agent may be (0.90-3.60):173.70:(3-4):(2-3), for example, 0.90:173.70:3.6:2.7, 1.80:173.70:3.6:2.7, or 3.60:173.70:3.6:2.7. The binder may be selected conventionally in the art, such as PVDF. The conductive agent may be selected conventionally in the art, such as SP.

[0110] In a fifth aspect, the present invention provides an electrode plate, which is made using the electrode slurry as described above.

[0111] In the present invention, the method for preparing an electrode plate using the electrode slurry can be conventional in the art, and generally comprises: coating the electrode slurry on at least one surface of a current collector, and drying.

[0112] In a sixth aspect, the present invention provides a battery comprising the electrode plate as described above.

[0113] In the present invention, the battery is preferably a lithium-ion battery.

[0114] On the basis of conforming to the common sense in this field, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0115] The reagents and raw materials used in the present invention are commercially available.

[0116] The positive progress effect of the present invention is:

[0117] The present invention designs the structure of the repeating units in the molecular chain of the acrylate polymer to obtain a novel acrylate polymer. The molecular chains of the acrylate polymer are all fatty groups, which can avoid increasing the rigidity of the polymer chain segments and help to obtain excellent dispersion, viscosity reduction and viscosity stabilization effects. First, the acrylate monomer M-1 is conducive to the formation of a strong adsorption of the dispersant on the carbon material or carbon-coated material; secondly, the interaction between the acrylate monomer M-2 and the volatile small molecule amine compound B can enhance the adsorption effect and provide a charge repulsion effect; furthermore, the methoxy-terminated polyether monomer M-3 has good chemical stability and better segment flexibility compared to the existing methoxy polyethylene glycol acrylate monomer. Based on this, the dispersant of the present invention is used in the process of preparing electrode slurry, which has excellent dispersion, viscosity reduction and viscosity stabilization effects, further improving the quality stability of the battery. DETAILED DESCRIPTION

[0118] The present invention is further illustrated by way of examples below, but the present invention is not limited to the scope of the examples. Experimental methods in the following examples where specific conditions are not specified were performed according to conventional methods and conditions, or selected according to the product specifications.

[0119] In the following synthesis examples and comparative synthesis examples:

[0120] (1) Weight average molecular weight and molecular weight distribution index (PDI)

[0121] The weight average molecular weight and molecular weight distribution index of the polymer were determined using a Waters 1515 gel permeation chromatograph, calibrated with standard polystyrene, and N-methylpyrrolidone as the mobile phase at a column temperature of approximately 90°C.

[0122] (2) Solid content

[0123] Solid content refers to the mass percentage of solids in a slurry or solution.

[0124] Synthesis Example 1

[0125] Into a 2000 ml four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a dropping device, 300.0 g of propylene glycol methyl ether acetate was added, and the mixture was stirred and heated to 80°C.

[0126] Simultaneously, an initiator solution prepared by dissolving 6.0 g of benzoyl peroxide in 188.0 g of propylene glycol methyl ether acetate and a monomer solution prepared by dissolving 780.0 g of lauryl methacrylate (M-1), 180.0 g of acrylic acid (M-2), 240.0 g of polyethylene glycol (n=9) allyl methyl ether (M-3), and 6.0 g of n-dodecyl mercaptan in 300.0 g of propylene glycol methyl ether acetate were added dropwise. The dropping time was controlled at 420 minutes and 360 minutes, respectively, and the reaction temperature was controlled at 78-82° C. After the dropwise addition was completed, the mixture was kept at 78-82° C. for 120 minutes to complete the polymerization reaction. After the holding period was completed, the mixture was cooled to below 50° C. to obtain a polymer solution containing the acrylate polymer (A-1) having a solids content of 60.2%.

[0127] The weight average molecular weight of the acrylic acid ester polymer (A-1) was 49,600, and the molecular weight distribution index (PDI) was 1.92.

[0128] Synthesis Example 2

[0129] 300.0 g of N,N-dimethylformamide was added to a 2000 ml five-necked flask equipped with a stirrer, N2 inlet tube, thermometer, reflux condenser, and dropping device. The air in the four-necked flask was replaced by N2, and the mixture was stirred and heated to 65°C.

[0130] Simultaneously, an initiator solution prepared by dissolving 3.0 g of azobisisobutyronitrile in 295.0 g of N,N-dimethylformamide and a monomer solution prepared by dissolving 400.0 g of stearyl acrylate (M-1), 100.0 g of acrylic acid (M-2), 500.0 g of polyethylene glycol (n=16) vinyl methyl ether (M-3), and 2.0 g of mercaptoethanol in 400.0 g of N,N-dimethylformamide were added dropwise. The addition times were controlled at 420 and 360 minutes, respectively, and the reaction temperature was controlled at 65-70°C. After the addition was completed, the mixture was kept at 65-70°C for 60 minutes to complete the polymerization reaction. After the holding period, the temperature was lowered to below 50°C to obtain a polymer solution containing the acrylate polymer (A-2) with a solids content of 50.1%.

[0131] The weight average molecular weight of the acrylic acid ester polymer (A-2) was 36,200, and the molecular weight distribution index (PDI) was 1.85.

[0132] Synthesis Example 3

[0133] Into a 2000 ml four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a dropping device, 300.0 g of butyl acetate was added, and the mixture was heated to 90° C. with stirring.

[0134] Simultaneously, an initiator solution prepared by dissolving 3.0 g of azobisisoheptanenitrile in 296.4 g of butyl acetate and a monomer solution prepared by dissolving 180.0 g of docosyl acrylate (M-1), 120.0 g of methacrylic acid (M-2), 300.0 g of polypropylene glycol (n=20) allyl butyl ether (M-3), and 0.6 g of octyl 3-mercaptopropionate in 800.0 g of butyl acetate were added dropwise. The addition times were controlled at 420 minutes and 360 minutes, respectively, and the reaction temperature was controlled at 90-95° C. After the addition was completed, the mixture was kept at 90-95° C. for 30 minutes to complete the polymerization reaction. After the holding period was completed, the temperature was lowered to below 50° C. to obtain a polymer solution containing the acrylate polymer (A-3) having a solids content of 30.1%.

[0135] The weight average molecular weight of the acrylic acid ester polymer (A-3) was 68,300, and the molecular weight distribution index (PDI) was 2.15.

[0136] Synthesis Example 4

[0137] 300.0 g of N-methylpyrrolidone was added to a 2000 ml four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a dropping device. The air in the four-necked flask was replaced by nitrogen and the mixture was stirred and heated to 60°C.

[0138] Simultaneously, an initiator solution prepared by dissolving 6.0 g of 4,4'-azobis(4-cyanovaleric acid) in 190.4 g of N-methylpyrrolidone and a monomer solution prepared by dissolving 720.0 g of hexadecyl acrylate (M-1), 60.0 g of acrylic acid (M-2), 360.0 g of allyl polyethylene glycol polypropylene glycol (n=45) acetate (M-3), 60.0 g of styrene, and 3.6 g of 3-mercaptopropionic acid in 300.0 g of N-methylpyrrolidone were added dropwise. The addition times were controlled at 420 and 360 minutes, respectively, and the reaction temperature was controlled at 60-65°C. After the addition was completed, the mixture was kept at 60-65°C for 120 minutes to complete the polymerization reaction. After the incubation period, the temperature was lowered to below 50°C to obtain a polymer solution containing an acrylate polymer (A-4) with a solids content of 59.9%.

[0139] The weight average molecular weight of the acrylic acid ester polymer (A-4) was 28,100, and the molecular weight distribution index (PDI) was 1.65.

[0140] Synthesis Example 5

[0141] Into a 2000 ml four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a dropping device, 300.0 g of N,N-dimethylformamide was added, and the mixture was stirred and heated to 60°C.

[0142] Simultaneously, an initiator solution prepared by dissolving 6.0 g of benzoyl peroxide in 190.2 g of N,N-dimethylformamide, a reducing agent solution prepared by dissolving 3.0 g of N,N-dimethylaniline in 100.0 g of N,N-dimethylformamide, and a monomer solution prepared by dissolving 200.0 g of stearyl acrylate (M-1), 300.0 g of lauryl methacrylate (M-1), 100.0 g of acrylic acid (M-2), 400.0 g of methallyl polyethylene glycol (n=6) acetate (M-3), and 0.8 g of mercaptoethanol in 400.0 g of N,N-dimethylformamide were added dropwise. The addition times were controlled at 420 minutes, 420 minutes, and 360 minutes, respectively, and the reaction temperature was controlled at 60-65° C. After the addition was completed, the reaction mixture was kept at 60-65° C. for 60 minutes to complete the polymerization reaction. After the heat preservation was completed, the temperature was lowered to below 50° C. to obtain a polymer solution containing an acrylic acid ester polymer (A-5) with a solid content of 50.2%.

[0143] The weight average molecular weight of the acrylic acid ester polymer (A-5) was 52,800, and the molecular weight distribution index (PDI) was 1.75.

[0144] Comparative Synthesis Example 1

[0145] Compared with Synthesis Example 2, the only difference is that stearyl acrylate is replaced by isooctyl acrylate, and a polymer solution containing polymer P-1 is obtained, which has a solid content of 50.0%, a weight-average molecular weight of 37100, and a molecular weight distribution index (PDI) of 1.83.

[0146] Comparative Synthesis Example 2

[0147] Compared with Synthesis Example 4, the only difference is that the monomer solution is replaced with a monomer solution obtained by dissolving 240.0 g of hexadecyl acrylate, 60.0 g of acrylic acid, 840.0 g of allyl polyethylene glycol polypropylene glycol (n=45) acetate, 60.0 g of styrene, and 3.6 g of 3-mercaptopropionic acid in 300.0 g of N-methylpyrrolidone. The resulting polymer solution contains polymer P-2 and has a solid content of 59.5%, a weight-average molecular weight of 27,300, and a molecular weight distribution index (PDI) of 1.63.

[0148] Comparative Synthesis Example 3

[0149] The acrylate comb dispersant prepared in Example 5 of invention patent CN115975104A is labeled as P-3. The obtained polymer solution has a solid content of 47.3%, a weight average molecular weight of 52,300, and a molecular weight distribution index of 2.13.

[0150] Comparative Synthesis Example 4

[0151] Compared with Synthesis Example 1, the only difference is that 240.0 g of polyethylene glycol (n=9) allyl methyl ether (M-3) in the monomer solution is replaced with 240.0 g of methoxy polyethylene glycol (n=9) acrylate, thereby obtaining a polymer solution containing polymer P-4 having a solid content of 60.2%, a weight-average molecular weight of 51,300, and a molecular weight distribution index of 1.96.

[0152] The main raw materials used in the synthesis examples and comparative examples are summarized in Table 1.

[0153] Table 1

[0154] Preparation Examples and Comparative Examples

[0155] The polymer solutions obtained in Synthesis Examples 1-5 and Comparative Synthesis Examples 1-5 were uniformly mixed with PVP K30 (Luvitec K30, manufactured by BASF GmbH, Germany), volatile small molecule amine compound B, and solvent C in the mass ratios shown in Table 2 to obtain dispersants D01-D09 in Preparation Examples 1-9 of the present invention and dispersants D10-D15 in Comparative Preparation Examples 1-6. The preparation results are shown in Table 3. It should be noted that since the polymer solutions themselves contain a certain amount of solvent, the solvent amount in Table 2 refers to the amount of additional solvent, while the solvent content in Table 3 refers to the total solvent content in the dispersants.

[0156] Table 2 Dispersant preparation raw materials in preparation examples and preparation comparative examples

[0157] Table 3 Dispersant compositions in preparation examples and comparative examples

[0158] Application Example 1: Electrode Slurry Containing Carbon Nanotubes (CNTs)

[0159] Carbon nanotubes H (CNT) are used, and their main technical indicators are shown in Table 4.

[0160] Table 4 Technical indicators of carbon nanotubes H (CNT)

[0161] Use a ball mill to grind and disperse according to the scheme in Table 5. After all the CNTs are added, grind for 3 hours to obtain an electrode slurry containing CNTs (referred to as CNT slurry).

[0162] Table 5 CNT slurry preparation scheme

[0163] The rotational viscosity of the CNT slurry in Table 5 was tested using a rotational viscometer 1 hour, 24 hours, 3 days, 7 days, 14 days, and 30 days after the grinding. The results are shown in Table 6.

[0164] Reference standard: GB / T 10247-2008 Viscosity test method, instrument model: DV-2TLV Brookfield viscometer, key parameters are as follows:

[0165] Rotor: Select according to viscosity range; Speed: 60 rpm; Time: 3 min; Test temperature: 25°C.

[0166] Table 6 Rotational viscosity of CNT slurry after storage for different times (viscosity unit: mPa·s)

[0167] Note: X indicates that a uniform slurry cannot be obtained, and ※ indicates that the slurry is gelled.

[0168] From the data comparison of CNT-D02 and CNT-D10 slurries, it can be preliminarily seen that when preparing the dispersant P1 in the CNT-D10 slurry, the M-1 monomer in the synthetic comparative example 1 is isooctyl acrylate, that is, the carbon chain length is only 8, which is lower than the carbon chain length of R1 in the synthetic example 2, and cannot play the role of viscosity reduction and viscosity stabilization, which will cause the slurry to gel.

[0169] From the data comparison of CNT-D03, CNT-D06, CNT-D07, CNT-D08 and CNT-D09 slurries, as well as the data comparison of CNT-D12 and CNT-D13 slurries, it can be preliminarily seen that when preparing the dispersant in the slurry, as the proportion of volatile small molecule amine increases, the viscosity reduction and viscosity stabilization effects first increase and then decrease. In the CNT-D08 slurry, when the weight proportion of volatile small molecule amine in the dispersant is 9.0 parts, that is, 9wt% of the polymer, the viscosity reduction and viscosity stabilization effects reach excellent results.

[0170] From the data comparison of CNT-D04 and CNT-D11 slurries, it can be preliminarily seen that when preparing the dispersant P2 in the CNT-D11 slurry, in the synthesis comparison example 2, the mass percentage of the M-3 monomer allyl polyethylene glycol polypropylene glycol (n=45) acetate reached 70%, resulting in a significant decrease in the viscosity reduction and viscosity stabilization effects.

[0171] From the data comparison of CNT-D05 and CNT-D15 slurries, it can be preliminarily seen that when preparing the dispersant P4 in the CNT-D15 slurry, in the synthetic comparative example 4, the M-3 monomer adopts methoxy polyethylene glycol acrylate, that is, the group connected to the main chain carbon is changed from the alkylene group in the synthetic example 1 to the carbonyl group, which greatly reduces the viscosity reduction and stabilization effects.

[0172] In summary, from the results in Table 6, it can be seen that the viscosity reduction and viscosity stabilization effects of CNT-D01 to CNT-D09 slurries obtained by using the dispersant of the preparation example are significantly better than those of CNT-D10 to CNT-D15 obtained by using the dispersant of the preparation comparative example.

[0173] Application Example 2: Electrode slurry containing carbon-coated lithium iron phosphate (C@LFP)

[0174] The lithium iron phosphate product 10P (C@LFP) is used, and its main technical indicators are shown in Table 7.

[0175] Table 7 Technical indicators of lithium iron phosphate products 10P

[0176] Use a homogenizer to perform homogenization and dispersion according to the scheme in Table 8 to obtain an electrode slurry containing C@LFP (referred to as C@LFP slurry).

[0177] Table 8 Homogenization scheme of C@LFP slurry

[0178] The rotational viscosity of the C@LFP slurry in Table 8 was tested after 1 hour of discharge and 24 hours of storage. The results are shown in Table 9.

[0179] Reference standard: GB / T 10247-2008 Viscosity test method, instrument model: DV-2TLV Brookfield viscometer, key parameters are as follows:

[0180] Rotor: Select according to viscosity range; Speed: 60 rpm; Time: 3 min; Test temperature: 25°C.

[0181] Table 9 Rotational viscosity of C@LFP slurry

[0182] From the data comparison of 10P-D02 and 10P-D10 slurries, it can be preliminarily seen that when preparing the dispersant P1 in the 10P-D10 slurry, the M-1 monomer used in Synthesis Comparative Example 1 is isooctyl acrylate, that is, the carbon chain length is only 8, which is lower than the carbon chain length of R1 in Synthesis Example 2, and cannot achieve the viscosity reducing and stabilizing effects.

[0183] From the data comparison of 10P-D03, 10P-D06, 10P-D07, 10P-D08 and 10P-D09 slurries, it can be preliminarily seen that when preparing the dispersant in the slurry, as the proportion of volatile small molecule amine increases, the viscosity reduction and viscosity stabilization effects first increase and then decrease. In 10P-D03, 10P-D08 and 10P-D09 slurries, when the weight proportion of volatile small molecule amine in the dispersant is 3-27 parts, that is, 3wt%-27wt% of the polymer, the viscosity reduction and viscosity stabilization effects achieve better results.

[0184] From the data comparison of 10P-D04 and 10P-D11 slurries, it can be preliminarily seen that when preparing the dispersant P2 in the 10P-D11 slurry, compared with Synthesis Example 2, the mass percentage of the M-3 monomer allyl polyethylene glycol polypropylene glycol (n=45) acetate reached 70%, resulting in a significant decrease in the viscosity reduction and viscosity stabilization effects.

[0185] From the data comparison of 10P-D05 and 10P-D15 slurries, it can be preliminarily seen that when preparing the dispersant P4 in the 10P-D15 slurry, in the synthetic comparative example 4, the M-3 monomer adopts methoxy polyethylene glycol acrylate, that is, the group connected to the main chain carbon is changed from the alkylene group in the synthetic example 1 to the carbonyl group, which greatly reduces the viscosity reduction and stabilization effects.

[0186] In summary, from the results in Table 9, it can be seen that the viscosity reducing and stabilizing effects of slurries 10P-D01 to 10P-D09 obtained by using the dispersant prepared in the example are significantly better than those of slurries 10P-D10 to 10P-D15 obtained by using the dispersant prepared in the comparative example.

[0187] The present invention illustrates the detailed method of the present invention through the above embodiments, but it does not mean that the present invention must rely on the above embodiments. The embodiments in this section are only exemplary and explanatory and should not have any limiting effect on the scope of protection of the present invention.

Claims

1. An acrylate polymer, characterized in that, It includes repeating unit I, repeating unit II and repeating unit III; based on the total mass of the acrylate polymer, the mass percentage of repeating unit I is 30.0% - 70.0%; the mass percentage of repeating unit III is 20.0% - 60.0%; The structure of the repeating unit I is shown in formula (I): In each repeating unit I, R1 is independently hydrogen or methyl; Each R2 is independently C 10 -C 25 alkyl; The structure of the repeating unit II is shown in Formula (II): In each repeating unit II, R3 is independently hydrogen or methyl; Z is independently hydrogen, Li + , Na + , K + , NH4 + or an organic amine group with a molecular weight within 150; The structure of the repeating unit III is shown in formula (III): In each repeating unit III, R4 is independently hydrogen or methyl; Group A is independently -(CH2) p1 -; In each A group, p1 is independently an integer from 0 to 2; The B groups are each independently In each B group, each R5 is independently hydrogen or methyl, each R6 is independently hydrogen, an alkyl group having 1 to 18 carbon atoms or an acyl group having 2 to 6 carbon atoms, and each n1 is independently 4 to 70.

2. The acrylate polymer according to claim 1, wherein In the acrylate polymer, repeating unit I, repeating unit II and repeating unit III are randomly distributed; and / or, the weight-average molecular weight of the acrylate polymer is 10,000 - 70,000, preferably 28,100 - 68,300, more preferably 36,200 - 52,800, such as 28,100, 36,200, 49,600, 52,800 or 68,300; and / or, the molecular weight distribution index of the acrylate polymer is not greater than 2.20, preferably 1.65 - 2.15, more preferably 1.65 - 1.92, such as 1.65, 1.75, 1.85, 1.92 or 2.15; and / or, the mass percentage of repeating unit I is 30.0% - 65.0%, preferably 40.0% - 65.0%, such as 30.0%, 40.0%, 50.0%, 60.0% or 65.0%; and / or, the mass percentage of repeating unit II is 5.0% - 20.0%, preferably 10.0% - 15.0%, such as 5.0%, 10.0%, 15.0% or 20.0%; and / or, the mass percentage of repeating unit III is 20.0% - 50.0%, such as 20.0%, 30.0%, 40.0% or 50.0%; and / or, the acrylate polymer further includes repeating unit IV, and repeating unit IV is the repeating unit corresponding to styrene; the mass percentage of repeating unit IV is preferably 5.0% - 20.0%; and / or, the acrylate polymer does not include repeating units containing amino groups; and / or, in each repeating unit I, R1 and R2 independently satisfy any one of the following cases ① - ⑤: ①Each R2 is independently C 12 -C 25 alkyl, preferably C 16 -C 22 alkyl, such as C 18 alkyl; ②R1 is methyl; R2 is an alkyl group of C 12 ; ③R1 is hydrogen; R2 is an alkyl group of C 18 ; ④R1 is hydrogen; R2 is an alkyl group of C 22 ; ⑤R1 is hydrogen; R2 is an alkyl group of C 16 ; and / or, in each repeating unit II, R3 and Z satisfy any one of the following cases ① - ②: ① R3 is hydrogen and Z is hydrogen; ② R3 is methyl; Z is hydrogen; and / or, in each repeating unit III, the A group, B group, R4, R5, R6, p1, n1 satisfy any one of the following cases ① - ⑧: ① In each A group, p1 is 0 or 1; ② In each B group, R6 is methyl, butyl or acetyl; ③ In each B group, n1 is 6 - 45, such as 6, 9, 16, 20 or 45; ④ R4 and R5 are both hydrogen; R6 is methyl; p1 is 1; ⑤ R4 and R5 are both hydrogen; R6 is methyl; p1 is 0; ⑥ R4 is hydrogen; R5 is methyl; R6 is butyl; p1 is 1; ⑦ R4 is hydrogen; R5 is hydrogen or methyl; R6 is acetyl; p1 is 1; ⑧ R4 is methyl; R5 is hydrogen; R6 is acetyl; p1 is 1; Preferably, the acrylate polymer is any one of A-1 to A-5: A-1: In repeating unit I, R1 is methyl and R2 is an alkyl group of C 12 ; in repeating unit II, R3 is hydrogen and Z is hydrogen; in repeating unit III, R4 is hydrogen, p1 = 1, R5 is hydrogen, and R6 is methyl; the mass percentage of repeating unit I is 65.0%, the mass percentage of repeating unit II is 15.0%, and the mass percentage of repeating unit III is 20.0%, excluding repeating units containing amino groups; A-2: In repeating unit I, R1 is hydrogen and R2 is an alkyl group of C 18 ; in repeating unit II, R3 is hydrogen and Z is hydrogen; in repeating unit III, R4 is hydrogen, p1 = 0, R5 is hydrogen, and R6 is methyl; the mass percentage of repeating unit I is 40.0%, the mass percentage of repeating unit II is 10.0%, and the mass percentage of repeating unit III is 50.0%, excluding repeating units containing amino groups; A-3: In repeating unit I, R1 is hydrogen and R2 is an alkyl group of C 22 ; in repeating unit II, R3 is methyl and Z is hydrogen; in repeating unit III, R4 is hydrogen, p1 = 1, R5 is methyl, and R6 is butyl; the mass percentage of repeating unit I is 30.0%, the mass percentage of repeating unit II is 20.0%, and the mass percentage of repeating unit III is 50.0%, excluding repeating units containing amino groups; A-4: The acrylate polymer further includes repeating unit IV - the repeating unit corresponding to styrene; in repeating unit I, R1 is hydrogen and R2 is an alkyl group of C 16 ; in repeating unit II, R3 is hydrogen and Z is hydrogen; in repeating unit III, R4 is hydrogen, p1 = 1, and in each B group, R5 is hydrogen or methyl and R6 is acetyl; the mass percentage of repeating unit I is 60.0%, the mass percentage of repeating unit II is 5.0%, the mass percentage of repeating unit III is 30.0%, the mass percentage of repeating unit IV is 5.0%, and repeating units containing amine groups are not included; A-5: In each repeating unit I, R1 is hydrogen or methyl, and R2 is an alkyl group of C 12 or an alkyl group of C 18 ; in repeating unit II, R3 is hydrogen and Z is hydrogen; in repeating unit III, R4 is methyl, p1 = 1, R5 is hydrogen, and R6 is acetyl; the mass percentage of repeating unit I is 50.0%, the mass percentage of repeating unit II is 10.0%, and the mass percentage of repeating unit III is 40.0%, excluding repeating units containing amino groups; And / or, the carbon nanotube-containing electrode paste prepared from the acrylate polymer can reach a rotational viscosity of 182 mPa·s after 1 h of storage and 620 mPa·s after 28 days of storage under the viscosity test method of GB / T 10247-2008; And / or, the electrode paste containing carbon-coated lithium iron phosphate prepared from the acrylate polymer can reach a rotational viscosity of 8700 mPa·s after 1 h of storage and 12600 mPa·s after 24 h of storage under the viscosity test method of GB / T 10247-2008.

3. A method for preparing an acrylate polymer, characterized in that, It includes the following steps: Carry out a radical polymerization reaction on the raw materials to obtain it; wherein, the raw materials include polymerization monomers, and the polymerization monomers include monomer M-1, monomer M-2 and monomer M-3; based on the total mass of the polymerization monomers, the mass percentage of monomer M-1 is 30.0%-70.0%; the mass percentage of monomer M-3 is 20.0%-60.0%; The structure of the monomer M-1 is shown in Formula M-1 as follows: Wherein, R1 and R2 are as defined in claim 1 or 2; The structure of the monomer M-2 is shown in Formula M-2 as follows: Wherein, R3 and Z are as defined in claim 1 or 2; The structure of the monomer M-3 is as shown in Formula M-3: Wherein, A, B and R4 are as defined in claim 1 or 2.

4. The method for preparing an acrylate polymer according to claim 3, wherein, The monomer M-1 is one or more of lauryl methacrylate, stearyl acrylate, docosyl acrylate and hexadecyl acrylate; And / or, the mass percentage of the monomer M-1 is 30.0%-65.0%, preferably 40.0%-65.0%, such as 30.0%, 40.0%, 50.0%, 60.0% or 65.0%; And / or, the monomer M-2 is acrylic acid or methacrylic acid; And / or, the mass percentage of the monomer M-2 is 2.0%-20.0%, preferably 10.0%-15.0%, such as 5.0%, 10.0%, 15.0% or 20.0%; And / or, the monomer M-3 is allyl methyl polyglycol ether, vinyl methyl polyglycol ether, allyl butyl polypropylene glycol ether, allyl polyglycol polypropylene glycol acetate or methyl allyl polyglycol acetate; And / or, the mass percentage of the monomer M-3 is 20.0%-50.0%, such as 20.0%, 30.0%, 40.0% or 50.0%; And / or, the sum of the mass percentages of the monomer M-1, monomer M-2 and monomer M-3 is 90.0%-100.0%, preferably 95.0%-100.0%, such as 95.0% or 100.0%; And / or, the polymerization monomers further include monomer M-4; the monomer M-4 is preferably styrene; the mass percentage of the monomer M-4 is preferably 5.0%-20.0%; And / or, the polymerization monomers do not include amine-containing monomers.

5. The preparation method of the acrylate polymer according to claim 3, wherein, The radical polymerization reaction is carried out in a solvent; the solvent is preferably one or more of ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone, such as propylene glycol monomethyl ether acetate, N,N-dimethylformamide, butyl acetate, or N-methylpyrrolidone; And / or, the raw materials further include an initiator and a chain transfer agent; Preferably, the initiator is a peroxide initiator, an azo initiator, or a redox initiator composed of a peroxide initiator and a reducing agent; the peroxide initiator is preferably benzoyl peroxide, dilauroyl peroxide, diisopropylbenzene peroxide, cumene hydroperoxide, methyl ethyl ketone peroxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, tert-butyl peroxypivalate, tert-butyl peroxyneopentanoate, tert-butyl peroxyisobutyrate, tert-butyl peroxy(2-ethylhexanoate), 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxyisopropylbenzene, or 1,4-bis(tert-butylperoxy)cumene; the azo initiator is preferably azobisisobutyronitrile, azobisisopentanenitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, 1,1'-azobis(cyanocyclohexane), 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), azodimidinylpropane, 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis(2-methyl-N-(2-hydroxyethyl)propionamide), 2,2-azobisisobutylamidine dihydrochloride, or 2,2'-azobis(2-imidazoline) dihydrochloride; the reducing agent is preferably an amine compound, more preferably tetramethylethylenediamine, N,N-dimethylaniline, N,N-dimethyl-p-toluidine, ethylenediamine, diethylenetriamine, triethylenetetramine, or tetraethylenepentamine; Preferably, the initiator is added dropwise into the reaction system in the form of an initiator solution; the dropping time is more preferably 360-420 min; Preferably, the chain transfer agent is one or more of mercapto carboxylic acid chain transfer agents, mercaptan chain transfer agents, isopropyl alcohol, and hypophosphorous acid; the mercapto carboxylic acid chain transfer agent is more preferably mercaptoacetic acid, 3-mercaptopropionic acid, ethyl 3-mercaptopropionate, butyl 3-mercaptopropionate, octyl 3-mercaptopropionate, or trimethylolpropane tris(3-mercaptopropionate); the mercaptan chain transfer agent is more preferably mercaptoethanol, butyl mercaptan, hexyl mercaptan, octyl mercaptan, or dodecyl mercaptan; Preferably, the chain transfer agent is added dropwise into the reaction system in the form of a monomer solution; the monomer solution more preferably includes a polymerization monomer and the chain transfer agent; the dropping time is more preferably 360-420 min; And / or, the reaction temperature of the radical polymerization reaction is 60-95 °C; the reaction temperature of the radical polymerization reaction preferably satisfies any one of the following conditions ①-④: ① The reaction temperature of the radical polymerization reaction is 78-82 °C; ② The reaction temperature of the radical polymerization reaction is 65 - 70 °C; ③ The reaction temperature of the radical polymerization reaction is 90 - 95 °C; ④ The reaction temperature of the radical polymerization reaction is 60 - 65 °C; And / or, the reaction time of the radical polymerization reaction is 30 - 120 min, such as 30 min, 60 min or 120 min; And / or, the radical polymerization reaction is carried out under a protective atmosphere; The protective atmosphere is preferably nitrogen or an inert gas.

6. An acrylate polymer, characterized in that, It is obtained by using the preparation method of the acrylate polymer according to any one of claims 3 - 5.

7. A dispersant, characterized in that, It includes the acrylate polymer according to any one of claims 1, 2 and 6, a volatile small molecule amine compound and a solvent; Wherein, the mass ratio of the acrylate polymer to the volatile small molecule amine compound is 100:(1 - 100).

8. The dispersant according to claim 7, wherein The volatile small molecule amine compound is one or more of triethylamine, tri-n-butylamine, ethylenediamine, butanediamine, hexanediamine, monoethanolamine, monoisopropanolamine, n-propanolamine, N,N-dimethylethanolamine, 2-amino-2-methyl-1-propanol, hydroxyethyl ethylenediamine and hydroxyethyl hydrazine, such as butanediamine, monoethanolamine, n-propanolamine, N,N-dimethylethanolamine or 2-amino-2-methyl-1-propanol; And / or, the mass ratio of the acrylate polymer to the volatile small molecule amine compound is 100:1, 100:5, 100:10, 100:29.9 or 100:89.7; And / or, the mass ratio of the acrylate polymer to the solvent is 100:(50 - 5000), preferably 100:(100 - 1000), such as 100:139.9, 100:140, 100:140.1, 100:310.3, 100:370.1, 100:395.0, 100:399.0 or 100:890; And / or, the solvent is one or more of ethyl acetate, butyl acetate, propylene glycol methyl ether acetate, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone, such as propylene glycol methyl ether acetate, N,N-dimethylformamide, butyl acetate or N-methylpyrrolidone.

9. An electrode paste, characterized in that, It includes an electrode material and a dispersant according to claim 7 or 8.

10. The electrode paste according to claim 9, characterized in that, The electrode material is a carbon material or a carbon-coated material; Preferably, the carbon material is one or more of carbon nanotubes, graphene, acetylene black, porous carbon and conductive carbon black; Preferably, the carbon-coated material is one or two of carbon-coated lithium iron phosphate and carbon-coated lithium manganese iron phosphate; Preferably, the electrode paste is any one of the systems in ① and ②: ① The electrode paste includes: the dispersant, the carbon material and the solvent; The mass ratio of the dispersant to the carbon material is more preferably 12.5:(5.0 - 20.0), such as 12.5:5.0, 12.5:10.0 or 12.5:20.0; ② The electrode paste includes: the dispersant, the carbon-coated material, the binder, the conductive agent, and the solvent; the mass ratio of the dispersant, the carbon-coated material, the binder, and the conductive agent is more preferably (0.90 - 3.60):173.70:(3 - 4):(2 - 3), such as 0.90:173.70:3.6:2.7, 1.80:173.70:3.6:2.7, or 3.60:173.70:3.6:2.7; the binder is more preferably PVDF; the conductive agent is more preferably SP.

11. An electrode tab, characterized in that, It is prepared using the electrode paste according to claim 9 or 10.

12. A battery, characterized in that, It includes the electrode tab according to claim 11.

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