Polymer dispersing agent, preparation method, electrode slurry, electrode pole piece and battery

Abstract

A polymer dispersing agent, a preparation method, an electrode slurry, an electrode pole piece, and a battery. The polymer dispersing agent contains a repeating unit I, a repeating unit II, and a repeating unit III. The mole number a of the repeating unit I, the mole number b of the repeating unit II and the mole number c of the repeating unit III satisfy the following numerical relationships: a / (a+b)＝0.50 to 0.85, and (a+b) / c＝0.2 to 1.0. The preparation method is simple. The prepared polymer dispersing agent has a novel structure, can be used in an electrode slurry preparation process, and has excellent dispersion viscosity reduction and viscosity stabilization effects.

Description

Polymer dispersant, preparation method, electrode slurry, electrode plate and battery

[0001] This application claims the benefit of Chinese Patent Application No. 2023118032044 filed on December 26, 2023. This application incorporates the entirety of the aforementioned Chinese Patent Application. Technical Field

[0002] The invention relates to a polymer 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 fields, carbon materials represented by carbon nanotubes, graphene, and conductive carbon black and carbon-coated materials represented by lithium iron phosphate and lithium manganese iron phosphate have been widely used as battery electrode materials.

[0004] However, due to the special particle structure and surface morphology of this type of carbon material and carbon-coated material, when no dispersant is used or traditional polyvinyl pyrrolidone dispersants are used, problems such as poor particle dispersion, high slurry viscosity, and short storage time often occur during the preparation of electrode slurry, further affecting the quality stability of the battery.

[0005] Patent application CN115322293A discloses a dispersant, a preparation method, and its use in preparing a carbon nanotube dispersion. In the dispersant preparation method provided in this patent application, the reaction temperature of the maleic anhydride copolymer and the amine is always maintained at 80-150°C. In the resulting polymer, almost all of the maleic anhydride is ring-opened to form amide, which limits the viscosity-reducing and viscosity-stabilizing effects of the dispersant.

[0006] Summary of the Invention

[0007] The present invention overcomes the existing problems of poor particle dispersion, high slurry viscosity, and short storage life that often occur during the preparation of electrode slurries. It provides a polymer dispersant, a preparation method, an electrode slurry, an electrode plate, and a battery. The preparation method is simple, and the resulting polymer dispersant has a novel structure. It can be used in the preparation of electrode slurries and exhibits excellent dispersing, viscosity reduction, and viscosity stabilization.

[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 a polymer dispersant comprising a repeating unit I, a repeating unit II, and a repeating unit III;

[0010] The structure of the repeating unit I is shown in Formula I:

[0011] In each repeating unit I,

[0012] R1 and R2 are each independently hydrogen, methyl or ethyl;

[0013] R3 are each independently C 10 -C 25 An alkyl group or a group represented by formula (1);

[0014] In each group represented by formula (1), R4, R5, R6, and R7 are each independently hydrogen, methyl, or ethyl; R8 is each independently C1-C 18 alkyl; n is each independently 6-60;

[0015] The structure of the repeating unit II is shown in Formula II:

[0016] In each repeating unit II,

[0017] R1 and R2 are each independently hydrogen, methyl or ethyl;

[0018] R9, R 10 are independently hydrogen, C1-C 25 alkyl or R3; and R9 and R 10 Not simultaneously hydrogen;

[0019] Z is independently hydrogen, Li + 、Na + , K + NH4 + or an organic amine group with a molecular weight of less than 150;

[0020] The structure of the repeating unit III is shown in Formula III:

[0021] In each repeating unit III,

[0022] R 11 、R 12 、R 13 are each independently hydrogen, methyl or ethyl;

[0023] R 14 are independently hydrogen, phenyl, C1-C 18 Alkyl or C1-C 18 Alkoxy;

[0024] Wherein, the degree of polymerization a of the repeating unit I, the degree of polymerization b of the repeating unit II, and the degree of polymerization c of the repeating unit III satisfy the following quantitative relationship:

[0025] a / (a+b)=0.50~0.85, (a+b) / c=0.2~1.0.

[0026] In the present invention, “in each ..., ... are each independently ...” means that in the molecular chain of the polymer dispersant, in different repeating units represented by the same general formula, the groups represented by the same symbol may be the same or different.

[0027] For example, "In each repeating unit I, R1 and R2 are independently hydrogen, methyl, or ethyl" means that in the molecular chain of the polymer dispersant, R1 and R2 in different repeating units I represented by formula (I) may be the same or different, and R2 may be the same or different; and within the same repeating unit I, R1 and R2 do not affect each other and may be the same or different. Similarly, each repeating unit II and each repeating unit III has the same meaning.

[0028] For another example, it is necessary to explain that "in each group represented by formula (1), R4, R5, R6, and R7 are each independently hydrogen, methyl, or ethyl; R8 is each independently C1-C 18 alkyl; n is independently 6-60" means that in the molecular chain of the polymer dispersant, in different repeating units I represented by formula (I), when R3 is a group represented by formula (1), "n" in formula (1) can be the same or different; n In the embodiment, R4, R5, R6, and R7 may be the same or different.

[0029] In the present invention, the polymerization degree a, the polymerization degree b, and the polymerization degree c are calculated based on the feed ratio of the base polymer and the amine compound and the imidization rate.

[0030] In the present invention, in each repeating unit I, R3 can be independently C 12 -C 18 Alkyl groups, such as C 12 Alkyl, C 16 Alkyl or C 18 of alkyl.

[0031] In the present invention, in each repeating unit II, R9, R 10 Can be independently C 18 of alkyl.

[0032] In the present invention, the weight average molecular weight of the polymer dispersant may be 16,000-52,000, preferably 16,800-51,200, more preferably 16,800-27,800, further preferably 23,400-27,800, for example, 16,800, 20,200, 21,900, 23,400, 26,500, 27,800, 29,700, 35,900 or 51,200.

[0033] In the present invention, the molecular weight distribution index (PDI) of the polymer dispersant may be no greater than 2.00, preferably 1.59-1.92, more preferably 1.59-1.65, further preferably 1.63-1.65, for example 1.59, 1.60, 1.62, 1.63, 1.65, 1.75, 1.78 or 1.92.

[0034] In the present invention, the distribution of the repeating unit I, the repeating unit II and the repeating unit III may be one of the following:

[0035] ① The repeating unit I, the repeating unit II and the repeating unit III are randomly distributed;

[0036] ② The repeating unit I and the repeating unit II form a first block, and the repeating unit III forms a second block. In the first block, the repeating unit I and the repeating unit II are randomly distributed.

[0037] In the present invention, the degree of polymerization refers to the average number of repeating units represented by the same general formula in the molecular chain of the polymer dispersant. For example, the "degree of polymerization a of the repeating unit I" means the average number of repeating units I represented by formula (I) in the molecular chain of the polymer dispersant.

[0038] In the present invention, the value of a / (a+b) may be 0.55-0.82, preferably 0.55-0.81, for example, 0.55, 0.66, 0.70, 0.73, 0.77, 0.81 or 0.82.

[0039] In the present invention, the value of (a+b) / c may be 0.30-0.76, for example, 0.30, 0.39, 0.42 or 0.76.

[0040] In the present invention, the degree of polymerization a of the repeating unit I may be 1-100, preferably 4.70-12.22, more preferably 4.70-6.97, for example 4.70, 5.64, 5.98, 6.18, 6.51, 6.86, 6.97 or 12.22.

[0041] In the present invention, the degree of polymerization b of the repeating unit II may be 1-100, preferably 1.53-5.28, more preferably 1.53-3.80, for example 1.53, 1.64, 1.99, 2.32, 2.52, 2.86, 3.80 or 5.28.

[0042] In the present invention, the degree of polymerization c of the repeating unit III may be 10-200, preferably 11.15-45.00, such as 11.15, 20.48, 28.32 or 45.00.

[0043] In the present invention, the polymer dispersant may be any one of P-1 to P-9:

[0044] P-1: In each repeating unit I, R1 and R2 are hydrogen, and R3 is a group represented by formula (1) or C 12 alkyl, R4, R5 are hydrogen or methyl, R6, R7 are hydrogen, R8 is methyl; in repeating unit II, R1, R2 are hydrogen, R9, R 10 C 18 alkyl, Z is hydrogen; in repeating unit III, R 11 、R 12 、R 13 is hydrogen, R 14 is phenyl; a / (a+b)=0.70, (a+b) / c=0.76;

[0045] P-2: In each repeating unit I, R1 and R2 are hydrogen, and R3 is a group represented by formula (1) or C 16 alkyl, R4, R5 are hydrogen or methyl, R6, R7 are hydrogen, R8 is methyl; in repeating unit II, R1, R2 are hydrogen, R9, R 10 C 18 alkyl, Z is hydrogen; in repeating unit III, R 11 、R 12 、R 13 is hydrogen, R 14 is phenyl; a / (a+b)=0.73, (a+b) / c=0.76;

[0046] P-3: In each repeating unit I, R1 and R2 are hydrogen, and R3 is a group represented by formula (1) or C 18 alkyl, R4, R5 are hydrogen or methyl, R6, R7 are hydrogen, R8 is methyl; in repeating unit II, R1, R2 are hydrogen, R9, R 10 C 18 alkyl, Z is hydrogen; in repeating unit III, R 11 、R 12 、R 13 is hydrogen, R 14is phenyl; a / (a+b)=0.81, (a+b) / c=0.76;

[0047] P-4: In each repeating unit I, R1 and R2 are hydrogen, and R3 is a group represented by formula (1) or C 16 alkyl, R4, R5 are hydrogen or methyl, R6, R7 are hydrogen, R8 is methyl; in repeating unit II, R1, R2 are hydrogen, R9, R 10 C 18 alkyl, Z is hydrogen; in repeating unit III, R 11 、R 12 、R 13 is hydrogen, R 14 is phenyl; a / (a+b)=0.55, (a+b) / c=0.76;

[0048] P-5: In repeating unit I, R1 and R2 are hydrogen, and R3 is C 12 alkyl, R4, R5 are hydrogen or methyl, R6, R7 are hydrogen, R8 is methyl; in each repeating unit II, R1, R2 are hydrogen, R9, R 10 For hydrogen, C 18 or a group represented by formula (1), Z is hydrogen; in the repeating unit III, R 11 、R 12 、R 13 is hydrogen, R 14 is phenyl; a / (a+b)=0.66, (a+b) / c=0.76;

[0049] P-6: In each repeating unit I, R1 and R2 are hydrogen, and R3 is a group represented by formula (1) or C 12 alkyl, R4, R5 are hydrogen or methyl, R6, R7 are hydrogen, R8 is methyl; in repeating unit II, R1, R2 are hydrogen, R9 is hydrogen, R 10 C 18 alkyl, Z is hydrogen; in repeating unit III, R 11 、R 12 、R 13 is hydrogen, R 14 is phenyl; a / (a+b)=0.82, (a+b) / c=0.76;

[0050] P-7: In each repeating unit I, R1 and R2 are hydrogen, and R3 is a group represented by formula (1) or C 16 alkyl, R4, R5 are hydrogen or methyl, R6, R7 are hydrogen, R8 is methyl; in repeating unit II, R1, R2 are hydrogen, R9, R 10 C 18 alkyl, Z is hydrogen; in repeating unit III, R 11 、R12 、R 13 is hydrogen, R 14 is phenyl; a / (a+b)=0.77, (a+b) / c=0.42;

[0051] P-8: In each repeating unit I, R1 and R2 are hydrogen, and R3 is a group represented by formula (1) or C 16 alkyl, R4, R5 are hydrogen or methyl, R6, R7 are hydrogen, R8 is methyl; in repeating unit II, R1, R2 are hydrogen, R9, R 10 C 18 alkyl, Z is hydrogen; in repeating unit III, R 11 、R 12 、R 13 is hydrogen, R 14 is phenyl; a / (a+b)=0.70, (a+b) / c=0.30;

[0052] P-9: In each repeating unit I, R1 and R2 are hydrogen, and R3 is a group represented by formula (1) or C 16 alkyl, R4, R5 are hydrogen or methyl, R6, R7 are hydrogen, R8 is methyl; in repeating unit II, R1, R2 are hydrogen, R9, R 10 C 18 alkyl, Z is hydrogen; in repeating unit III, R 11 、R 12 、R 13 、R 14 is hydrogen; a / (a+b)=0.70, (a+b) / c=0.39.

[0053] In the present invention, the polymer dispersant can be prepared by the following method: reacting the reaction raw materials at 155-180° C. first, and then reacting at 60-150° C.; the reaction raw materials are the first raw material and the second raw material as described in the second aspect.

[0054] In the present invention, the carbon nanotube-containing electrode slurry prepared with the polymer dispersant has a viscosity of 528 mPa·s after storage for 1 hour and a viscosity of 2290 mPa·s after storage for 28 days at a rotation speed of 60 rpm, a time of 3 minutes, and a test temperature of 25°C according to the viscosity test method of GB / T 10247-2008.

[0055] In the present invention, the electrode slurry containing carbon-coated lithium iron phosphate prepared by the polymer dispersant has a viscosity of 5720 mPa·s after storage for 1 hour and a viscosity of 9520 mPa·s after storage for 28 days at a rotation speed of 60 rpm, a time of 3 minutes, and a test temperature of 25°C according to the GB / T 10247-2008 viscosity test method.

[0056] In a second aspect, the present invention provides a method for preparing a polymer dispersant, comprising the following steps:

[0057] S1. The first raw material is reacted at 155-180 ℃; the first raw material comprises a base polymer and a first amine compound;

[0058] S2 is cooled to 60-150 ℃, and the second raw material is continued to be added and reacted; the second raw material comprises the first amine compound or the second amine compound;

[0059] The first raw material and / or the second raw material further comprises a third amine compound;

[0060] The structure of the matrix polymer is shown in Formula M-1:

[0061] in,

[0062] R1, R2, R 11 、R 12 、R 13 and R 14 R1, R2, R 11 、R 12 、R 13 and R 14 ;

[0063] The ratio of d to e is (0.2-1.0):1;

[0064] The structure of the first amine compound is shown in Formula M-2:

[0065] H2N—R3

[0066] M-2

[0067] wherein R3 is R3 as described above;

[0068] The structure of the second amine compound is shown in Formula M-3:

[0069] Among them, R9 and R 10 As mentioned above, R9 and R 10 ;

[0070] The structure of the third amine compound is shown in Formula M-4:

[0071] wherein R4, R5, R6, R7, R8 and n are as described above.

[0072] In the present invention, in step S1, the first raw material may include the base polymer and the first amine compound.

[0073] In the present invention, in step S1, the first raw material may include the base polymer, the first amine compound and the third amine compound.

[0074] In the present invention, in step S2, the second raw material may include the first amine compound and the third amine compound.

[0075] In the present invention, in step S2, the second raw material may include the second amine compound and the third amine compound.

[0076] In the present invention, d may be 2-200.

[0077] In the present invention, e may be 10-200.

[0078] In the present invention, the number average molecular weight of the matrix polymer can be selected conventionally in the art, preferably 2000-3800, such as 2000, 3000 or 3800.

[0079] In the present invention, the acid value of the matrix polymer can be selected conventionally in the art, preferably 285-660 mgKOH / g, such as 285 mgKOH / g, 355 mgKOH / g, 480 mgKOH / g or 660 mgKOH / g.

[0080] In the present invention, the matrix polymer can be selected from conventional materials in the art, and is preferably maleic anhydride ethylene copolymer, SMA1000P, SMA2000P or SMA3000P.

[0081] In the present invention, the total amine value of the first amine compound can be selected conventionally in the art, preferably 210-300 mgKOH / g, such as 210 mgKOH / g, 223 mgKOH / g or 300 mgKOH / g.

[0082] In the present invention, the first amine compound may be a primary amine.

[0083] The primary amine can be selected from conventional ones in the art, preferably dodecyl primary amine, hexadecyl primary amine or octadecyl primary amine.

[0084] In the present invention, the total amine value of the second amine compound can be selected conventionally in the art, preferably 108 mgKOH / g.

[0085] In the present invention, the second amine compound may be a secondary amine.

[0086] The secondary amine can be selected from conventional amines in the art, preferably dioctadecylamine.

[0087] In the present invention, the third amine compound may be a polyetheramine.

[0088] The polyetheramine may be an alkyl-terminated monofunctional polyetheramine. Preferably, the polyetheramine may be an alkoxy polyethylene glycol polyetheramine, an alkoxy polypropylene glycol polyetheramine, an alkoxy polyethylene glycol polypropylene glycol random polyetheramine, or an alkoxy polyethylene glycol polypropylene glycol block polyetheramine; for example, the polyetheramine JEFFAMINE L100, the polyetheramine JEFFAMINE B60, or the polyetheramine JEFFAMINE B200 from Huntsman Corporation of the United States.

[0089] In the present invention, conventionally, the reactions of step S1 and step S2 are carried out in a solvent, which can be any organic solvent applicable in the art, such as N-methylpyrrolidone (NMP). The amount of the solvent can be selected within the applicable range in the art.

[0090] In step S1, the reaction temperature may be 158°C, 160°C, 165°C, 168°C, 175°C or 180°C.

[0091] In step S1, the reaction time is preferably 1.5-3 h, such as 1.5 h, 2 h, 2.5 h or 3 h, depending on the completion of the reaction.

[0092] In step S1, during the reaction, a protective gas may be used to remove the water generated by the reaction. The protective gas refers to a gas that does not react with the reaction system, such as nitrogen or an inert gas.

[0093] In step S2, the reaction temperature may be 80°C, 85°C, 90°C, 105°C, 110°C, 115°C, 120°C, 135°C or 140°C.

[0094] In step S2, the reaction time is preferably 2-3 hours, which is sufficient for the reaction to be completed.

[0095] In certain specific embodiments, the reaction temperature in step S1 is 158-165°C, and the reaction temperature in step S2 is 135-140°C.

[0096] In certain specific embodiments, the reaction temperature in step S1 is 168-175°C, and the reaction temperature in step S2 is 115-120°C.

[0097] In certain specific embodiments, the reaction temperature in step S1 is 175-180°C, and the reaction temperature in step S2 is 105-110°C.

[0098] In certain specific embodiments, the reaction temperature in step S1 is 160-165°C, and the reaction temperature in step S2 is 85-90°C.

[0099] In certain specific embodiments, the reaction temperature in step S1 is 160-165°C, and the reaction temperature in step S2 is 80-90°C.

[0100] In certain specific embodiments, the reaction temperature in step S1 is 160-165°C, and the reaction temperature in step S2 is 105-110°C.

[0101] In a third aspect, the present invention provides a polymer dispersant obtained by the preparation method of the polymer dispersant as described above.

[0102] In a fourth aspect, the present invention provides an electrode slurry comprising an electrode material and the polymer dispersant as described above.

[0103] In the present invention, the electrode material may be a carbon material or a carbon-coated material.

[0104] 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.

[0105] Wherein, the carbon-coated material is one or both of carbon-coated lithium iron phosphate and carbon-coated lithium manganese iron phosphate.

[0106] The electrode slurry may include: the polymer dispersant, the carbon material and a viscosity reducer.

[0107] The viscosity reducer can be a conventional choice in the art, such as the D603 product of Ruigu New Energy (Shanghai) Materials Technology Co., Ltd.

[0108] The mass ratio of the polymer dispersant, the carbon material and the viscosity reducer may be (2-8):1:(0.05-0.5), for example, 4:1:0.1.

[0109] The electrode slurry may include: the polymer dispersant, the carbon coating material, a binder and a conductive agent.

[0110] The binder can be selected conventionally in the art, such as PVDF.

[0111] The conductive agent can be selected from conventional ones in the art, such as carbon nanotubes, conductive carbon black (SP), acetylene black, etc.

[0112] The mass ratio of the polymer dispersant, the carbon coating material, the binder and the conductive agent may be (0.2-0.8):173.70:(3-4):(2-3), for example, 0.35:173.70:3.6:2.7.

[0113] In a fifth aspect, the present invention provides an electrode plate, which is made using the electrode slurry as described above.

[0114] 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.

[0115] In a sixth aspect, the present invention provides a battery comprising the electrode plate as described above.

[0116] In the present invention, the battery is preferably a lithium-ion battery.

[0117] Based on the common sense in the art, the above preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention. The reagents and raw materials used in the present invention are all commercially available.

[0118] The positive progress effect of the present invention is:

[0119] The present invention designs the structure of the repeating units in the molecular chain of the polymer dispersant, specifically based on a controlled ring-opening reaction of a maleic anhydride-ethylene copolymer, to obtain a polymer dispersant with a novel structure. The molecular chain of the polymer dispersant contains a specific content of an imidized five-membered ring structure and a specific content of a carboxylic acid group. On the one hand, compared with conventional non-cyclic structures, the imidized five-membered ring structure has better stability and better adsorption effect on carbon materials, making it more suitable for application in electrode slurries; on the other hand, the carboxylic acid group can further enhance the dispersing effect. Based on this, the polymer dispersant of the present invention has excellent dispersing, viscosity-reducing and viscosity-stabilizing effects when used in the process of preparing electrode slurries. DETAILED DESCRIPTION

[0120] 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.

[0121] In the following synthesis examples and comparative synthesis examples:

[0122] (1) Weight average molecular weight and molecular weight distribution index (PDI)

[0123] 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.

[0124] (2) Solid content

[0125] Solid content refers to the mass percentage of solids in a slurry or solution.

[0126] (3) Imidization rate

[0127] Calculation method of imidization rate:

[0128] Imidization rate = (number of moles of carboxylic acid in the starting material - number of moles of carboxylic acid in the reaction product - number of moles of primary amine in the reaction material) / number of moles of primary amine in the reaction material × 100%

[0129] The main raw materials used in the following synthesis examples and comparative synthesis examples are shown in Table 1:

[0130] Table 1

[0131] Synthesis Example 1

[0132] S1. Add 1640.0 g of NMP to a 3000 ml four-necked flask equipped with a stirrer, thermometer, reflux condenser, and feeding device. Start stirring, add 400.0 g (about 0.20 mol) of SMA1000P, and raise the temperature to below 150°C to completely dissolve the SMA1000P. Add 185.4 g (about 1.00 mol) of pre-heated and melted dodecyl primary amine, and raise the temperature to 158°C. Maintain the reaction temperature at 158-165°C, add 300.0 g (about 0.30 mol) of pre-heated and melted polyetheramine JEFFAMINE L100, and keep the reaction warm for 3 hours. Remove the water generated by the imidization reaction with nitrogen.

[0133] S2. The temperature of the reaction mass was then lowered to 135-140° C., and 208.8 g (about 0.40 mol) of pre-melted dioctadecylamine was added. The reaction was continued at this temperature for 2 h, and then the temperature was lowered and the material was discharged to obtain a polymer solution containing polymer dispersant P-1, with a solid content of 40% and an imidization rate of 92%.

[0134] The weight average molecular weight of the polymer dispersant P-1 was 21,900, and the molecular weight distribution index (PDI) was 1.60.

[0135] Synthesis Example 2

[0136] S1. Add 1950.0 g of NMP to a 3000 ml four-necked flask equipped with a stirrer, thermometer, reflux condenser, and feeding device. Start stirring, add 400.0 g (approximately 0.40 mol) of SMA1000P, and raise the temperature to below 150°C to completely dissolve the SMA1000P. Then, add 193.2 g (approximately 0.8 mol) of hexadecyl primary amine, which had been previously heated and melted, and raise the temperature to 158°C. Then, add 500.0 g (0.50 mol) of polyetheramine JEFFAMINE L100, which had been previously heated and melted. The temperature was raised to 168-175°C and the mixture was kept warm for 2 hours. The water generated by the imidization reaction was removed by nitrogen.

[0137] S2. The temperature of the reaction mass was then lowered to 115-120° C., and 208.8 g (about 0.40 mol) of pre-melted dioctadecylamine was added. The reaction was continued for 2 h, and then the temperature was lowered and the material was discharged to obtain a polymer solution containing polymer dispersant P-2, with a solid content of 40% and an imidization rate of 95%.

[0138] The weight average molecular weight of the polymer dispersant P-2 was 26,500, and the molecular weight distribution index (PDI) was 1.62.

[0139] Synthesis Example 3

[0140] S1. Add 1700.0 g of NMP to a 3000 ml four-necked flask equipped with a stirrer, thermometer, reflux condenser, and feeding device. Start stirring, add 400.0 g (approximately 0.40 mol) of SMA1000P, and raise the temperature to below 150°C to completely dissolve the SMA1000P. Then, add 215.6 g (approximately 0.80 mol) of pre-melted octadecyl primary amine; then add 360.0 g (approximately 0.60 mol) of polyetheramine JEFFAMINE B60. Raise the temperature to 175-180°C and maintain the reaction for 1.5 hours. Remove the water generated by the imidization reaction with nitrogen.

[0141] S2. The temperature of the reaction mass was then lowered to 105-110° C., and 156.6 g (about 0.30 mol) of pre-melted dioctadecylamine was added. The reaction was continued for 2 h, and then the temperature was lowered and the material was discharged to obtain a polymer solution containing polymer dispersant P-3, with a solid content of 40% and an imidization rate of 98%.

[0142] The weight average molecular weight of the polymer dispersant P-3 was 23,400, and the molecular weight distribution index (PDI) was 1.65.

[0143] Synthesis Example 4

[0144] S1. Add 1700.0 g of NMP to a 3000 ml four-necked flask equipped with a stirrer, thermometer, reflux condenser, and feeding device. Start stirring, add 333.3 g (approximately 0.17 mol) of SMA1000P, and raise the temperature to below 150°C to completely dissolve the SMA1000P. Then, add 161.0 g (approximately 0.67 mol) of hexadecyl primary amine, which had been previously melted, and then add 333.3 g (approximately 0.17 mol) of polyetheramine JEFFAMINE B200. Raise the temperature to 160-165°C and maintain the reaction for 2.5 hours. Remove the water generated by the imidization reaction with nitrogen.

[0145] S2. The temperature of the reaction mass was then lowered to 85-90° C., 304.5 g (about 0.58 mol) of pre-melted dioctadecylamine was added, and the reaction was continued for 3 h. The temperature was then lowered and the material was discharged to obtain a polymer solution containing polymer dispersant P-4, with a solid content of 40% and an imidization rate of 94%.

[0146] The weight average molecular weight of the polymer dispersant P-4 was 27,800, and the molecular weight distribution index (PDI) was 1.63.

[0147] Synthesis Example 5

[0148] S1. Add 1470.0 g of NMP to a 3000 ml four-necked flask equipped with a stirrer, thermometer, reflux condenser, and charging device. Start stirring, add 400.0 g (approximately 0.40 mol) of SMA1000P, and raise the temperature to below 150°C to completely dissolve the SMA1000P. Add 222.5 g (approximately 1.20 mol) of pre-melted dodecyl primary amine; raise the temperature to 160-165°C and maintain the reaction for 2.5 hours. Remove the water generated by the imidization reaction with nitrogen.

[0149] S2. The temperature of the reaction mass was then lowered to 80-90° C., and 156.6 g (about 0.30 mol) of pre-melted dioctadecylamine and 200.0 g (about 0.20 mol) of polyetheramine JEFFAMINE L100 were added. The reaction was continued for 3 h, and then the temperature was lowered and the material was discharged to obtain a polymer solution containing polymer dispersant P-5, which had a solid content of 40% and an imidization rate of 94%.

[0150] The weight average molecular weight of the polymer dispersant P-5 was 16,800, and the molecular weight distribution index (PDI) was 1.59.

[0151] Synthesis Example 6

[0152] S1. Add 1450.0 g of NMP to a 3000 ml four-necked flask equipped with a stirrer, thermometer, reflux condenser, and feeding device. Start stirring, add 400.0 g (approximately 0.40 mol) of SMA1000P, and raise the temperature to below 150°C to completely dissolve the SMA1000P. Then, add 241.0 g (approximately 1.30 mol) of pre-melted dodecyl primary amine; then add 300.0 g (approximately 0.30 mol) of polyetheramine JEFFAMINE L100. The temperature is raised to 160-165°C and maintained for 2 hours. The water generated by the imidization reaction is removed by nitrogen.

[0153] S2. The temperature of the reaction mass was then lowered to 105-110° C., 27.0 g (about 0.10 mol) of octadecyl primary amine, which had been heated and melted in advance, was added, and the reaction was continued for 2 h. The temperature was then lowered and the material was discharged to obtain a polymer solution containing polymer dispersant P-6, with a solid content of 40% and an imidization rate of 82%.

[0154] The weight average molecular weight of the polymer dispersant P-6 was 20200, and the molecular weight distribution index (PDI) was 1.62.

[0155] Synthesis Example 7

[0156] S1. Add 1980.0 g of NMP to a 3000 ml four-necked flask equipped with a stirrer, thermometer, reflux condenser, and feeding device. Start stirring, add 600.0 g (approximately 0.20 mol) of SMA2000P, and raise the temperature to below 150°C to completely dissolve the SMA2000P. Then, add 265.7 g (approximately 1.10 mol) of hexadecyl primary amine, which had been previously melted, and then add 300.0 g (approximately 0.30 mol) of polyetheramine JEFFAMINE L100. The temperature was raised to 160-165°C and the reaction was maintained for 2.5 hours. The water generated by the imidization reaction was removed with nitrogen.

[0157] S2. The temperature of the reaction mass was then lowered to 105-110° C., and 156.6 g (about 0.30 mol) of pre-melted dioctadecylamine was added. The reaction was continued for 3 h, and then the temperature was lowered and the material was discharged to obtain a polymer solution containing polymer dispersant P-7, with a solid content of 40% and an imidization rate of 93%.

[0158] The weight average molecular weight of the polymer dispersant P-7 was 29,700, and the molecular weight distribution index (PDI) was 1.75.

[0159] Synthesis Example 8

[0160] S1. Add 1900.0 g of NMP to a 3000 ml four-necked flask equipped with a stirrer, thermometer, reflux condenser, and feeding device. Start stirring, add 633.3 g (approximately 0.17 mol) of SMA3000P, and raise the temperature to below 150°C to completely dissolve the SMA3000P. Add 201.3 g (approximately 0.83 mol) of pre-melted hexadecyl primary amine; then add 250.0 g (approximately 0.25 mol) of polyetheramine JEFFAMINE L100. Raise the temperature to 160-165°C and maintain the reaction for 2.5 hours. Remove the water generated by the imidization reaction with nitrogen.

[0161] S2. The temperature of the reaction mass was then lowered to 105-110° C., and 174.0 g (about 0.33 mol) of pre-melted dioctadecylamine was added. The reaction was continued for 3 h, and then the temperature was lowered and the material was discharged to obtain a polymer solution containing polymer dispersant P-8, with a solid content of 40% and an imidization rate of 92%.

[0162] The weight average molecular weight of the polymer dispersant P-8 was 35,900, and the molecular weight distribution index (PDI) was 1.78.

[0163] Synthesis Example 9

[0164] S1. Add 1900.0 g of NMP to a 3000 ml four-necked flask equipped with a stirrer, thermometer, reflux condenser, and feeding device. Start stirring, add 300.0 g (about 0.10 mol) of maleic anhydride-ethylene copolymer, and raise the temperature to below 150° C. to completely dissolve the maleic anhydride-ethylene copolymer. Then, add 241.5 g (about 1.00 mol) of hexadecyl primary amine, which had been previously heated and melted. Then, add 300.0 g (about 0.30 mol) of polyetheramine JEFFAMINE L100. The temperature is raised to 160-165° C. and the mixture is kept warm for 2.5 hours. The water generated by the imidization reaction is removed by nitrogen.

[0165] S2. The temperature of the reaction mass was then lowered to 105-110° C., and 234.9 g (about 0.45 mol) of pre-melted dioctadecylamine was added. The reaction was continued for 3 h, and then the temperature was lowered and the material was discharged to obtain a polymer solution containing polymer dispersant P-9, with a solid content of 40% and an imidization rate of 94%.

[0166] The weight average molecular weight of the polymer dispersant P-9 was 51,200, and the molecular weight distribution index (PDI) was 1.92.

[0167] Comparative Synthesis Example 1

[0168] Compared to Synthesis Example 3, the only difference was that the octadecyl primary amine was replaced with an equal molar amount of n-octylamine. The resulting polymer was labeled S-1, and the imidization rate was 98%. The weight-average molecular weight of polymer dispersant S-1 was 22,700, and the molecular weight distribution index (PDI) was 1.64.

[0169] Comparative Synthesis Example 2

[0170] Compared to Synthesis Example 3, the only difference was that the reaction temperature was controlled at 105-110°C throughout the entire process. The resulting polymer was labeled S-2, and the imidization rate was 8%. The polymer dispersant S-2 had a weight-average molecular weight of 22,100 and a molecular weight distribution index (PDI) of 1.63.

[0171] Comparative Synthesis Example 3

[0172] Compared to Synthesis Example 6, the only difference was that the reaction temperature was controlled at 160-165°C throughout the entire process. The resulting polymer was labeled S-3, and the overall imidization rate was measured at the end of the reaction to be 97%. The weight-average molecular weight of polymer dispersant S-3 was 21,100, and the molecular weight distribution index (PDI) was 1.64.

[0173] Comparative Synthesis Example 4

[0174] Prepared according to Example 2 of Chinese Invention Patent CN115322293A, the overall imidization rate was 12% at the end of the reaction and is designated S-4. Polymer dispersant S-4 has a weight-average molecular weight of 27,100 and a molecular weight distribution index (PDI) of 1.62.

[0175] The main raw materials and process parameters of the synthesis examples and comparative examples are summarized in Table 2. Some characteristic parameters of the prepared polymer dispersants are shown in Table 3:

[0176] Table 2

[0177] Table 3

[0178] Among them, taking P-1 as an example,

[0179] Degree of polymerization a = (number of moles of polyetheramine JEFFAMINE L100 + number of moles of dodecyl primary amine) × imidization ratio ÷ number of moles of SMA1000P = (0.30 + 1.00) × 0.92 ÷ 0.20 = 5.98;

[0180] Degree of polymerization b = [(number of moles of polyetheramine JEFFAMINE L100 + number of moles of dodecyl primary amine) × (1-imidization rate) + number of moles of dioctadecyl secondary amine] ÷ number of moles of SMA1000P = [(0.30 + 1.00) × (1.00 - 0.92) + 0.40] ÷ 0.20 = 2.52;

[0181] Degree of polymerization c = number average molecular weight of SMA1000P × mass percentage of styrene units in SMA1000P ÷ molar mass of styrene units = 2000 × 58% ÷ 10 4 = 11.15.

[0182] Similarly, a, b, and c in P-2 to P-9 and S-1 to S-3 can all be calculated with reference to P-1, as listed above.

[0183] Application Example 1: Electrode Slurry Containing Carbon Nanotubes (CNTs)

[0184] Carbon nanotubes G (CNT) are used, and their main technical indicators are shown in Table 4.

[0185] Table 4 Technical indicators of carbon nanotubes G (CNT)

[0186] A sand mill was used to grind and disperse the CNTs in a mass ratio of CNT: polymer dispersant (effective portion): viscosity reducer: NMP = 4.0%: 1.0%: 0.1%: 94.9%. The grinding was completed after all the CNTs were added for 3 hours to obtain a CNT-containing electrode slurry (hereinafter referred to as CNT slurry). The polymer dispersants were the polymer dispersants prepared in Synthesis Examples 1-9 and Comparative Synthesis Examples 1-4, and the conventional dispersant PVP K30. The corresponding electrode slurries prepared were respectively designated CNT-01 to CNT-14, as shown in Table 5. The viscosity reducer used was D603 product from Ruigu New Energy (Shanghai) Materials Technology Co., Ltd.

[0187] The rotational viscosity was then 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 5.

[0188] Reference standard: GB / T 10247-2008 Viscosity test method, instrument model: DV-2TLV Brookfield viscometer, key parameters are as follows:

[0189] Rotor: Select according to viscosity range; Speed: 60 rpm; Time: 3 min; Test temperature: 25°C.

[0190] Table 5 Rotational viscosity of CNT slurry after storage for different times (viscosity unit: mPa·s)

[0191] Note: PVP K30 adopts Luvitec K30 produced by BASF GmbH of Germany.

[0192] From the data comparison of CNT-03 slurry and CNT-10 slurry, it can be seen that when preparing the polymer dispersant in CNT-10 slurry, the primary amine in Synthesis Comparative Example 1 uses n-octylamine, that is, the carbon chain length is only 8, which is lower than the carbon chain length of R3 in Synthesis Example 3, and it is difficult to achieve the effect of viscosity reduction and viscosity stabilization.

[0193] From the data comparison of CNT-03 slurry and CNT-11 slurry, it can be seen that when preparing the polymer dispersant in CNT-11 slurry, the reaction temperature of 105-110°C was used in all the synthesis comparison examples 2, resulting in a small number of repeating units with a five-membered ring structure, resulting in very limited improvement in the viscosity reduction and viscosity stabilization effects.

[0194] From the data comparison of CNT-06 slurry and CNT-12 slurry, it can be seen that when preparing the polymer dispersant in CNT-12 slurry, the reaction temperature of 160-165°C was used in all synthetic comparative examples 3, resulting in an excessive number of repeating units with a five-membered ring structure, resulting in very limited improvements in the viscosity reduction and viscosity stabilization effects.

[0195] In summary, from the results in Table 5, it can be seen that the viscosity reduction and viscosity stabilization effects of CNT-01 to CNT-09 prepared using the polymer dispersant of the present invention are significantly better than those of CNT-10 to CNT-14 prepared using the comparative dispersant.

[0196] Application Example 2: Electrode slurry containing carbon-coated lithium iron phosphate (C@LFP)

[0197] The lithium iron phosphate product 10P (C@LFP) is used, and its main technical indicators are shown in Table 6.

[0198] Table 6 Technical indicators of lithium iron phosphate products 10P

[0199] A homogenizer was used to perform homogenization and dispersion according to the protocol in Table 7 to obtain an electrode slurry containing C@LFP (referred to as C@LFP slurry). The polymer dispersants were the polymer dispersants prepared in Synthesis Examples 1-9 and Comparative Synthesis Examples 1-4, and the conventional dispersant PVP K30. The numbers of the corresponding electrode slurries are shown in Table 7.

[0200] The rotational viscosity was then tested after 1 hour of discharge and 24 hours of storage. The results are shown in Table 8.

[0201] Reference standard: GB / T 10247-2008 Viscosity test method, instrument model: DV-2TLV Brookfield viscometer, key parameters are as follows:

[0202] Rotor: Select according to viscosity range; Speed: 60 rpm; Time: 3 min; Test temperature: 25°C.

[0203] Table 7 Homogenization scheme of C@LFP slurry

[0204] Table 8 Rotational viscosity of C@LFP slurry

[0205] From the data comparison of 10P-P3 slurry and 10P-S1 slurry, it can be seen that when preparing the polymer dispersant in 10P-S1 slurry, the primary amine in Synthesis Comparative Example 1 adopts n-octylamine, that is, the carbon chain length is only 8, which is lower than the carbon chain length of R3 in Synthesis Example 3, and it is difficult to achieve the viscosity reducing and stabilizing effects.

[0206] From the data comparison of 10P-P3 slurry and 10P-S2 slurry, it can be seen that when preparing the polymer dispersant in 10P-S2 slurry, the reaction temperature of 105-110°C was used in all the synthesis comparative examples 2, resulting in a small number of repeating units with a five-membered ring structure, resulting in very limited improvement in the viscosity reduction and viscosity stabilization effects.

[0207] From the data comparison of 10P-P6 slurry and 10P-S3 slurry, it can be seen that when preparing the polymer dispersant in 10P-S3 slurry, the reaction temperature of 160-165°C was used in all the synthesis comparative examples 3, resulting in an excessive number of repeating units with a five-membered ring structure, resulting in very limited improvements in the viscosity reduction and viscosity stabilization effects.

[0208] In summary, the results in Table 8 show that the viscosity reduction and stabilization effects of slurries 10P-P1 to 10P-P9 prepared using the dispersants of the present invention are significantly superior to those of slurries 10P-K30, 10P-S1 to 10P-S4 prepared using comparative dispersants. While the above examples illustrate the detailed methods of the present invention, they do not necessarily imply that the present invention must rely on these examples. The examples in this section are merely exemplary and explanatory and should not limit the scope of protection of the present invention in any way.

Claims

1. A polymer dispersant, characterized in that, It contains repeating unit I, repeating unit II, and repeating unit III; The structure of the repeating unit I is shown in Formula I: In each repeating unit I, R1 and R2 are each independently hydrogen, methyl, or ethyl; Each R3 is independently C 10 -C 25 alkyl or a group represented by formula (1); Among the groups represented by each formula (1), R4, R5, R6, and R7 are each independently hydrogen, methyl, or ethyl; R8 is each independently an alkyl group having 1 to 18 C; n is each independently 6 - 60; The structure of the repeating unit II is shown in Formula II: In each repeating unit II, R1 and R2 are each independently hydrogen, methyl, or ethyl; R9, R 10 each independently represents hydrogen, an alkyl group having 1 to C 25 or R3; and R9 and R 10 are not simultaneously hydrogen; 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, R 11 、R 12 、R 13 are each independently hydrogen, methyl or ethyl; R 14 each independently is hydrogen, phenyl, a C1-C 18 alkyl group or a C1-C 18 alkoxy group; Wherein, the degree of polymerization a of the repeating unit I, the degree of polymerization b of the repeating unit II, and the degree of polymerization c of the repeating unit III satisfy the following quantitative relationship: a / (a + b) = 0.50 to 0.85, (a + b) / c = 0.2 to 1.

0.

2. The polymer dispersant according to claim 1, wherein In each repeating unit I, each R3 is independently C 12 -C 18 alkyl, such as C 12 alkyl, C 16 alkyl or C 18 alkyl; and / or, in each repeating unit II, R9, R 10 are each independently an alkyl group having 18 carbon atoms; And / or, the weight-average molecular weight of the polymer dispersant is 16,000 - 52,000, preferably 16,800 - 51,200, more preferably 16,800 - 27,800, even more preferably 23,400 - 27,800, such as 16,800, 20,200, 21,900, 23,400, 26,500, 27,800, 29,700, 35,900, or 51,200; And / or, the PDI of the polymer dispersant is not greater than 2.00, preferably 1.59 - 1.92, more preferably 1.59 - 1.65, even more preferably 1.63 - 1.65, such as 1.59, 1.60, 1.62, 1.63, 1.65, 1.75, 1.78, or 1.92; And / or, the distribution of the repeating unit I, the repeating unit II, and the repeating unit III is One of the following situations: ① The repeating unit I, the repeating unit II, and the repeating unit III are randomly distributed; ② The repeating unit I and the repeating unit II form a first block, and the repeating unit III forms a second block. In the first block, the repeating unit I and the repeating unit II are randomly distributed; And / or, the value of a / (a + b) is 0.55 - 0.82, preferably 0.55 - 0.81, such as 0.55, 0.66, 0.70, 0.73, 0.77, 0.81, or 0.82; And / or, the value of (a + b) / c is 0.30 - 0.76, such as 0.30, 0.39, 0.42, or 0.76; And / or, the degree of polymerization a of the repeating unit I is 1 - 100, preferably 4.70 - 12.22, more preferably 4.70 - 6.97, such as 4.70, 5.64, 5.98, 6.18, 6.51, 6.86, 6.97, or 12.22; And / or, the degree of polymerization b of the repeating unit II is 1 - 100, preferably 1.53 - 5.28, more preferably 1.53 - 3.80, such as 1.53, 1.64, 1.99, 2.32, 2.52, 2.86, 3.80, or 5.28; And / or, the degree of polymerization c of the repeating unit III is 10 - 200, preferably 11.15 - 45.00, such as 11.15, 20.48, 28.32, or 45.00; Preferably, the polymer dispersant is any one of P-1 to P-9: P-1: In each repeating unit I, R1 and R2 are hydrogen, R3 is a group represented by formula (1) or an alkyl group of C 12 , R4 and R5 are hydrogen or methyl, R6 and R7 are hydrogen, and R8 is methyl; in repeating unit II, R1 and R2 are hydrogen, R9 and R 10 are an alkyl group of C 18 , and Z is hydrogen; in repeating unit III, R 11 , R 12 , R 13 are hydrogen, R 14 is phenyl; a / (a + b) = 0.70, (a + b) / c = 0.76; P-2: In each repeating unit I, R1 and R2 are hydrogen, R3 is a group represented by formula (1) or an alkyl group of C 16 , R4 and R5 are hydrogen or methyl, R6 and R7 are hydrogen, and R8 is methyl; in repeating unit II, R1 and R2 are hydrogen, R9 and R 10 are an alkyl group of C 18 , and Z is hydrogen; in repeating unit III, R 11 , R 12 , R 13 are hydrogen, R 14 is phenyl; a / (a + b) = 0.73, (a + b) / c = 0.76; P-3: In each repeating unit I, R1 and R2 are hydrogen, R3 is a group represented by formula (1) or an alkyl group of C 18 wherein R4 and R5 are hydrogen or methyl, R6 and R7 are hydrogen, and R8 is methyl; in repeating unit II, R1 and R2 are hydrogen, R9 and R 10 are an alkyl group of C 18 and Z is hydrogen; in repeating unit III, R 11 , R 12 , and R 13 are hydrogen. R 14 is phenyl; a / (a + b) = 0.81, (a + b) / c = 0.76; P-4: In each repeating unit I, R1 and R2 are hydrogen, R3 is a group represented by formula (1) or an alkyl group of C 16 , R4 and R5 are hydrogen or methyl, R6 and R7 are hydrogen, and R8 is methyl; in repeating unit II, R1 and R2 are hydrogen, R9 and R 10 are an alkyl group of C 18 , and Z is hydrogen; in repeating unit III, R 11 , R 12 , R 13 are hydrogen, R 14 is phenyl; a / (a + b) = 0.55, (a + b) / c = 0.76; P-5: In repeating unit I, R1 and R2 are hydrogen, R3 is an alkyl group of C 12 , R4 and R5 are hydrogen or methyl, R6 and R7 are hydrogen, and R8 is methyl; in each repeating unit II, R1 and R2 are hydrogen, R9 and R 10 are hydrogen, an alkyl group of C 18 , or a group represented by formula (1), and Z is hydrogen; in repeating unit III, R 11 , R 12 , R 13 are hydrogen, and R 14 is phenyl; a / (a + b) = 0.66, (a + b) / c = 0.76; P-6: In each repeating unit I, R1 and R2 are hydrogen, R3 is a group represented by formula (1) or an alkyl group of C 12 , R4 and R5 are hydrogen or methyl, R6 and R7 are hydrogen, and R8 is methyl; in repeating unit II, R1 and R2 are hydrogen, R9 is hydrogen, R 10 is an alkyl group of C 18 , and Z is hydrogen; in repeating unit III, R 11 , R 12 , R 13 are hydrogen, R 14 is phenyl; a / (a + b) = 0.82, (a + b) / c = 0.76; P-7: In each repeating unit I, R1 and R2 are hydrogen, R3 is a group represented by formula (1) or an alkyl group of C 16 , R4 and R5 are hydrogen or methyl, R6 and R7 are hydrogen, and R8 is methyl; in repeating unit II, R1 and R2 are hydrogen, R9 and R 10 are an alkyl group of C 18 , and Z is hydrogen; in repeating unit III, R 11 , R 12 , and R 13 are hydrogen, and R 14 is phenyl; a / (a + b) = 0.77, (a + b) / c = 0.42; P-8: In each repeating unit I, R1 and R2 are hydrogen, R3 is a group represented by formula (1) or an alkyl group of C 16 , R4 and R5 are hydrogen or methyl, R6 and R7 are hydrogen, and R8 is methyl; in repeating unit II, R1 and R2 are hydrogen, R9 and R 10 are an alkyl group of C 18 , and Z is hydrogen; in repeating unit III, R 11 , R 12 , and R 13 are hydrogen, and R 14 is phenyl; a / (a + b) = 0.70, (a + b) / c = 0.30; P-9: In each repeating unit I, R1 and R2 are hydrogen, R3 is a group represented by formula (1) or an alkyl group of C 16 , R4 and R5 are hydrogen or methyl, R6 and R7 are hydrogen, and R8 is methyl; in repeating unit II, R1 and R2 are hydrogen, R9 and R 10 are an alkyl group of C 18 , and Z is hydrogen; in repeating unit III, R 11 , R 12 , R 13 , R 14 are hydrogen; a / (a + b) = 0.70, (a + b) / c = 0.39; and / or, the polymer dispersant is prepared by the following method: reacting the reaction raw materials at 155 - 180 °C first, and then reacting at 60 - 150 °C; the reaction raw materials are the first raw material and the second raw material as described in claim 3; and / or, for the carbon nanotube-containing electrode paste prepared from the polymer dispersant, at a rotation speed of 60 rpm, a time of 3 min, and a test temperature of 25 °C, according to the viscosity test method of GB / T 10247 - 2008, the viscosity after storage for 1 h can reach 528 mPa·s, and the viscosity after storage for 28 days can reach 2290 mPa·s; and / or, for the electrode paste containing carbon-coated lithium iron phosphate prepared from the polymer dispersant, at a rotation speed of 60 rpm, a time of 3 min, and a test temperature of 25 °C, according to the viscosity test method of GB / T 10247 - 2008, the viscosity after storage for 1 h can reach 5720 mPa·s, and the viscosity after storage for 28 days can reach 9520 mPa·s. It comprises the following steps:

3. A preparation method of a polymer dispersant, characterized in that, S1. React the first raw material at 155 - 180 °C; the first raw material includes a matrix polymer and a first amine compound; S2. Cool down to 60 - 150 °C, and continue to add the second raw material and react; the second raw material includes the first amine compound or a second amine compound; The first raw material and / or the second raw material further includes a third amine compound; wherein, The structure of the matrix polymer is shown in Formula M-1: the ratio of d to e is (0.2 - 1.0):1; R1, R2, R 11 , R 12 , R 13 and R 14 as defined in claim 1 or 2; the structure of the first amine compound is as shown in formula M-2: H2N—R3 wherein, R3 is as defined in claim 1 or 2; M-2 wherein, R4, R5, R6, R7, R8 and n are as defined in claim 1 or 2. The structure of the second amine compound is shown in Formula M-3: wherein, R9 and R 10 are as defined in claim 1 or 2; The structure of the third amine compound is shown in Formula M-4: d is 2 - 200; 4. The preparation method of the polymer dispersant according to claim 3, wherein, and / or, e is 10 - 200; and / or, the number average molecular weight of the matrix polymer is 2000 - 3800, such as 2000, 3000 or 3800; and / or, the acid value of the matrix polymer is 285 - 660 mgKOH / g, such as 285 mgKOH / g, 355 mgKOH / g, 480 mgKOH / g or 660 mgKOH / g; and / or, the matrix polymer is maleic anhydride-ethylene copolymer, SMA1000P, SMA2000P or SMA3000P; and / or, the total amine value of the first amine compound is 210 - 300 mgKOH / g, such as 210 mgKOH / g, 223 mgKOH / g or 300 mgKOH / g; and / or, the first amine compound is a primary amine; the primary amine is preferably dodecyl primary amine, hexadecyl primary amine or octadecyl primary amine; and / or, the total amine value of the second amine compound is 108 mgKOH / g; and / or, the second amine compound is a secondary amine; the secondary amine is preferably dioctadecylamine; and / or, the third amine compound is a polyetheramine; the polyetheramine is preferably an alkyl-capped monofunctional polyetheramine, and the polyetheramine is preferably alkoxy polyethylene glycol polyetheramine, alkoxy polypropylene glycol polyetheramine, alkoxy polyethylene glycol polypropylene glycol random polyetheramine or alkoxy polyethylene glycol polypropylene glycol block polyetheramine. ​ 5. The preparation method of the polymer dispersant according to claim 3, characterized in that, In step S1, the first raw material includes the matrix polymer and the first amine compound; And / or, in step S1, the first raw material includes the matrix polymer, the first amine compound, and the third amine compound; And / or, in step S2, the second raw material includes the first amine compound and the third amine compound; And / or, in step S2, the second raw material includes the second amine compound and the third amine compound; And / or, the reactions in steps S1 and S2 are carried out in a solvent, and the solvent is preferably NMP; And / or, in step S1, the reaction time is 1.5 - 3 h, such as 1.5 h, 2 h, 2.5 h, or 3 h; And / or, in step S1, during the reaction, a protective gas is used to carry out the water generated by the reaction; the protective gas is preferably nitrogen or an inert gas; And / or, in step S2, the reaction time is 2 - 3 h; And / or, the reaction temperature in step S1 and the reaction temperature in step S2 satisfy any one of the following cases ① - ⑥: ① The reaction temperature in step S1 is 158 - 165 °C, and the reaction temperature in step S2 is 135 - 140 °C; ② The reaction temperature in step S1 is 168 - 175 °C, and the reaction temperature in step S2 is 115 - 120 °C; ③ The reaction temperature in step S1 is 175 - 180 °C, and the reaction temperature in step S2 is 105 - 110 °C; ④ The reaction temperature in step S1 is 160 - 165 °C, and the reaction temperature in step S2 is 85 - 90 °C; ⑤ The reaction temperature in step S1 is 160 - 165 °C, and the reaction temperature in step S2 is 80 - 90 °C; ⑥ The reaction temperature in step S1 is 160 - 165 °C, and the reaction temperature in step S2 is 105 - 110 °C.

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

7. An electrode paste, characterized in that, It includes an electrode material and the polymer dispersant according to any one of claims 1, 2, and 6.

8. The electrode paste according to claim 7, wherein 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 ① and ②: ① The electrode paste includes: the polymer dispersant, the carbon material, and a viscosity reducer; the mass ratio of the polymer dispersant, the carbon material, and the viscosity reducer is more preferably (2 - 8):1:(0.05 - 0.5), such as 4:1:0.1; ② The electrode paste includes: the polymer dispersant, the carbon-coated material, a binder, and a conductive agent; the binder is preferably PVDF; the conductive agent is preferably carbon nanotubes, conductive carbon black, or acetylene black; the mass ratio of the polymer dispersant, the carbon-coated material, the binder, and the conductive agent is preferably (0.2 - 0.8):173.70:(3 - 4):(2 - 3), such as 0.35:173.70:3.6:2.

7.

9. An electrode tab, characterized in that, It is prepared using the electrode paste described in claim 7 or 8.

10. A battery, characterized in that, It includes the electrode tab described in claim 9.

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