A binder for a battery and a method for preparing and using the same

Abstract

The application belongs to the technical field of batteries, and particularly relates to a binder for batteries, a preparation method and application thereof. The preparation raw material of the binder for batteries comprises a first monomer, and the first monomer comprises an acrylic ester monomer containing a urea group and a phenylboronic acid structural unit. The application has the beneficial effects that the binder can form a large number of hydrogen bonds to improve the elasticity of the polymer binder, and the hydroxyl group and the amide group can form a cross-linking structure by reacting with the phenylboronic acid group, thereby greatly improving the mechanical strength of the polymer binder, and thus having a higher tensile strength and a larger elongation at break, being capable of adapting to and inhibiting a huge volume change of silicon-based active particles in a long cycle process, maintaining the integrity of the electrode structure, and improving the electrical performance of the battery.

Description

Technical Field

[0001] This invention belongs to the field of battery technology, specifically relating to a battery binder, its preparation method, and its application. Background Technology

[0002] As a crucial component of lithium / sodium-ion battery electrodes, binders typically constitute only a portion of the total electrode mass (≤20 wt%), serving to bind the active materials, conductive agents, and current collectors together. However, even a small amount of binder plays a critical role in maintaining the integrity of the electrode structure during charge and discharge. For electrode active materials that undergo significant volume changes or even pulverization during cycling, binders can, to a certain extent, help maintain the morphology of the active materials and suppress the impact of volume deformation and electrode pulverization on battery performance.

[0003] As the most commonly used binders in lithium-ion batteries, polyvinylidene fluoride (PVDF) and carboxymethyl cellulose (CMC) / styrene-butadiene rubber (SBR) binders play important roles. PVDF binders, however, rely solely on weak van der Waals forces to bond the electrode active material and current collector. When applied to active materials with large volume deformation or to fabricate high-quality loaded electrodes, they cannot effectively maintain the bond between the electrode active particles and the current collector, making it difficult to maintain the structural integrity of the electrode during long cycles. CMC / SBR binders exhibit better adhesion than PVDF due to the interaction between the polar groups on the polymer chain and the -OH groups on the surface of the Si-based active material. However, since the molecular weight of CMC extracted from natural cellulose is not adjustable, its mechanical properties are fixed and cannot be further optimized to improve them. Therefore, when applied to Si-based electrodes, it cannot effectively adapt to and suppress electrode volume expansion.

[0004] Currently, to address the aforementioned problems, various types of secondary battery electrode binders have been developed. For example, existing technologies disclose the preparation of an amphiphilic polymer binder using soap-free emulsion polymerization with hydrophilic and oleophilic structural units. This type of amphiphilic polymer binder exhibits good adhesion and low environmental pollution; however, its mechanical strength is low, failing to meet the binder requirements for large-volume deformation electrodes such as silicon-based electrodes. Existing technologies also disclose aqueous polymer latexes such as styrene-acrylate polymers and styrene-butadiene polymers. These polymer binders typically have low viscosity and contain a significant amount of emulsifier, which is detrimental to electrode slurry preparation.

[0005] Therefore, the design and development of novel high-mechanical-strength polymer binders are of great significance for the application of high-energy-density secondary batteries. Summary of the Invention

[0006] This application provides a battery binder, its preparation method, and its application, aiming to solve the problem that existing binders cannot meet the requirements of large-volume deformation electrodes.

[0007] The first aspect of this application provides a battery binder, the raw materials for preparing the battery binder including a first monomer, the first monomer including an acrylate monomer containing urea group and phenylboronic acid structural units.

[0008] The binder described in this application can form a large number of hydrogen bonds to enhance the elasticity of the polymer binder. In addition, hydroxyl and amide groups can react with phenylboronic acid groups to form a cross-linked structure, thereby significantly improving the mechanical strength of the polymer binder. Therefore, it has high tensile strength and large elongation at break, which can adapt to and suppress the huge volume deformation of silicon-based active particles during long cycles, maintain the integrity of the electrode structure, and improve the electrical performance of the battery.

[0009] According to some embodiments of the battery binder described in this application, the raw materials for preparing the battery binder further include a second monomer, the second monomer including a functional monomer that can undergo a condensation reaction with phenylboronic acid.

[0010] According to some embodiments of the battery binder described in this application, the raw materials for preparing the first monomer include isocyanate methacrylate and aminophenylboronic acid.

[0011] According to some embodiments of the battery binder described in this application, the molar ratio of the isocyanate methacrylate and the aminophenylboronic acid is 1:0.9-1.5.

[0012] According to some embodiments of the battery binder described in this application, the structural formula of the first monomer is:

[0013]

[0014] According to some embodiments of the battery binder described in this application, the second monomer includes acrylic acid, acrylamide, N-hydroxymethylacrylamide, hydroxyl-containing acrylates, etc. Polyethylene glycol monohydroxy acrylate and One or more of them.

[0015] According to some embodiments of the battery binder described in this application, the molar ratio of the first monomer to the second monomer is (1-99):(1-99).

[0016] According to some embodiments of the battery binder described in this application, the molar ratio of the first monomer to the second monomer is (5-10):(95-90).

[0017] A second aspect of this application provides a method for preparing the battery binder described in the first aspect of this application, comprising the following steps: subjecting raw material monomers to a condensation reaction.

[0018] The preparation method described in this application is simple and can be industrialized. It obtains a polymer structure that combines the excellent physicochemical properties of both monomers by performing a condensation reaction on the monomers.

[0019] According to some embodiments of the method for preparing the battery binder described in this application, the condensation reaction is carried out under the action of an initiator.

[0020] According to some embodiments of the method for preparing the battery binder described in this application, the initiator includes one or more of ammonium persulfate, potassium persulfate, and sodium persulfate.

[0021] According to some embodiments of the preparation method of the battery binder described in this application, the amount of initiator added is 0.5%-1.0% of the total mass of the first monomer and the second monomer.

[0022] According to some embodiments of the preparation method of the battery binder described in this application, the temperature of the condensation reaction is 70-90°C, and the time of the condensation reaction is 10-14 hours.

[0023] According to some embodiments of the method for preparing the battery binder described in this application, the preparation method further includes preparing the first monomer.

[0024] The preparation of the first monomer includes the following steps: nucleophilic addition reaction of isocyanate methacrylate and aminophenylboronic acid.

[0025] According to some embodiments of the method for preparing the battery binder described in this application, the nucleophilic addition reaction is carried out in an organic solvent; more preferably, the organic solvent includes one or more of dichloromethane, N,N-dimethylformamide, dimethyl sulfoxide, and ethylene glycol dimethyl ether.

[0026] According to some embodiments of the preparation method of the battery binder described in this application, the temperature of the nucleophilic addition reaction is 20-30°C; and the time of the nucleophilic addition reaction is 10-14 h.

[0027] A third aspect of this application provides a secondary battery, comprising the battery binder described in the first aspect of this application or the battery binder obtained by the preparation method described in the second aspect of this application.

[0028] The secondary battery described in this application has significantly improved electrochemical performance and markedly enhanced cycle stability due to the presence of the binder described in this application.

[0029] According to some embodiments of the secondary battery described in this application, the secondary battery further includes an electrode active material, a conductive agent, and the binder.

[0030] According to some embodiments of the secondary battery described in this application, the mass ratio of the electrode active material, the conductive agent and the binder is (50-95):(2-25):(3-25).

[0031] According to some embodiments of the secondary battery described in this application, the electrode active material includes a positive electrode active material and a negative electrode active material.

[0032] According to some embodiments of the secondary battery described in this application, the positive electrode active material includes one or more of lithium cobalt oxide, lithium iron manganese phosphate, lithium manganese oxide, lithium iron phosphate, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, sodium vanadium phosphate, lithium-rich manganese-based materials, sodium vanadium fluorinated phosphate, sodium iron pyrophosphate, and sodium nickel iron manganese oxide.

[0033] According to some embodiments of the secondary battery described in this application, the negative electrode active material includes one or more of lithium metal alloy, graphite, nano-silicon, silicon suboxide, and hard carbon.

[0034] According to some embodiments of the secondary battery described in this application, the conductive agent includes one or more of Super P conductive agent, Ketjen Black, acetylene black, and carbon nanotubes.

[0035] According to some embodiments of the secondary battery described in this application, the secondary battery includes lithium-ion batteries and sodium-ion batteries. Attached Figure Description

[0036] Figure 1 The graph shows the cycle performance of the battery prepared using the binder described in Example 1 of this application.

[0037] Figure 2 The graph shows the cycle performance of the battery prepared using the binder described in Example 2 of this application.

[0038] Figure 3 The graph shows the cycle performance of the battery prepared using the binder described in Example 3 of this application.

[0039] Figure 4 The graph shows the cycle performance of the battery prepared using the binder described in Example 4 of this application.

[0040] Figure 5 The graph shows the cycle performance of the battery prepared using the binder described in Example 5 of this application.

[0041] Figure 6 The graph shows the cycle performance of the battery prepared using CMC / SBR binder. Detailed Implementation

[0042] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0043] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0044] This application provides a battery adhesive, the raw materials for which the battery adhesive is prepared include a first monomer, the first monomer including an acrylate monomer containing urea and phenylboronic acid structural units.

[0045] The binder described in this application can form a large number of hydrogen bonds to enhance the elasticity of the polymer binder. In addition, hydroxyl and amide groups can react with phenylboronic acid groups to form a cross-linked structure, thereby significantly improving the mechanical strength of the polymer binder. Therefore, it has high tensile strength and large elongation at break, which can adapt to and suppress the huge volume deformation of silicon-based active particles during long cycles, maintain the integrity of the electrode structure, and improve the electrical performance of the battery.

[0046] In some embodiments of this application, the raw materials for preparing the battery binder further include a second monomer, the second monomer including a functional monomer that can undergo a condensation reaction with phenylboronic acid.

[0047] In some embodiments of this application, the raw materials for preparing the first monomer include isocyanate methacrylate and aminophenylboronic acid.

[0048] In some embodiments of this application, the molar ratio of the isocyanate methacrylate to the aminophenylboronic acid is 1:0.9-1.5; for example, 1:0.9, 1:1, 1:1.2, 1:1.3, 1:1.5, etc.

[0049] In some embodiments of this application, the structural formula of the first monomer is:

[0050]

[0051] In some embodiments of this application, the second monomer includes acrylic acid, acrylamide, N-hydroxymethylacrylamide, hydroxyl-containing acrylates, etc. Polyethylene glycol monohydroxy acrylate and One or more of them.

[0052] In some embodiments of this application, the molar ratio of the first monomer to the second monomer is (1-99):(1-99), such as 1:99, 2:98, 10:90, 20:80, 30:70, 60:40, 50:50, 65:35, 78:22, 85:15, 88:12, 90:10, 95:5, 99:1, etc.

[0053] In some embodiments of this application, the molar ratio of the first monomer to the second monomer is (5-10):(95-90), such as 5:95, 6:94, 7:93, 8:92, 9:91, 10:90, etc.

[0054] This application also provides a method for preparing the battery binder described in the first aspect of this application, comprising the following steps: subjecting raw material monomers to a condensation reaction to obtain a polymer structure that possesses the excellent physicochemical properties of both monomers.

[0055] In some embodiments of this application, the condensation reaction is carried out under the action of an initiator.

[0056] In some embodiments of this application, the initiator includes one or more of ammonium persulfate, potassium persulfate, and sodium persulfate. The initiators selected in this application have advantages such as low toxicity, low cost, ease of operation, and single-electron oxidation characteristics.

[0057] In some embodiments of this application, the amount of initiator added is 0.5%-1.0% of the total mass of the first monomer and the second monomer, such as 0.5%, 0.8%, 0.9%, 1.0%, etc. Controlling the amount of initiator added in this application within this range helps to obtain polymers with appropriate molecular weight and achieve a narrow molecular weight distribution of the polymer.

[0058] In some embodiments of this application, the temperature of the condensation reaction is 70-90°C, such as 70°C, 75°C, 80°C, 85°C, 90°C, etc., and the time of the condensation reaction is 10-14 hours, such as 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, etc. Controlling the temperature of the condensation reaction within this range is beneficial to improving the reaction rate and the activity of the initiator.

[0059] In some embodiments of this application, the preparation method further includes preparing the first monomer;

[0060] The preparation of the first monomer includes the following steps: nucleophilic addition reaction of isocyanate methacrylate and aminophenylboronic acid.

[0061] In some embodiments of this application, the nucleophilic addition reaction is carried out in an organic solvent; more preferably, the organic solvent includes one or more of dichloromethane, N,N-dimethylformamide, dimethyl sulfoxide, and ethylene glycol dimethyl ether.

[0062] In some embodiments of this application, the temperature of the nucleophilic addition reaction is 20-30°C; and the time of the nucleophilic addition reaction is 10-14 hours.

[0063] This application also provides a secondary battery, including the battery binder described in the first aspect of this application or the battery binder obtained by the preparation method described in the second aspect of this application.

[0064] Because the secondary battery contains the binder described in this application, its electrochemical performance is greatly improved, and the cycle stability of the battery is significantly improved.

[0065] In some embodiments of this application, the secondary battery includes an electrode active material, a conductive agent, and the binder.

[0066] In some embodiments of this application, the mass ratio of the electrode active material, the conductive agent, and the binder is (50-95):(2-25):(3-25), for example 50:25:25, 60:20:20, 60:25:15, 80:10:10, 80:15:5, 85:10:5, 90:7:3, 95:2:3, etc.

[0067] In some embodiments of this application, the electrode active material includes a positive electrode active material and a negative electrode active material.

[0068] In some embodiments of this application, the positive electrode active material includes one or more of lithium cobalt oxide, lithium iron manganese phosphate, lithium manganese oxide, lithium iron phosphate, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, sodium vanadium phosphate, lithium-rich manganese-based materials, sodium vanadium fluorinated phosphate, sodium iron pyrophosphate, and sodium nickel iron manganese oxide.

[0069] In some embodiments of this application, the negative electrode active material includes one or more of lithium metal alloy, graphite, silicon-based materials, and hard carbon.

[0070] In some embodiments of this application, the conductive agent includes one or more of Super P conductive agent, Ketjen Black, acetylene black, and carbon nanotubes.

[0071] In some embodiments of this application, the secondary battery includes lithium-ion batteries and sodium-ion batteries.

[0072] The present application will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0073] Example 1

[0074] A method for preparing a battery binder includes the following steps:

[0075] Under an argon atmosphere, 15.5 g of isocyanate methacrylate and 13.7 g of aminophenylboronic acid were dissolved in 150 mL of dichloromethane and stirred at a reaction temperature of 25 °C for 12 hours to obtain an acrylate monomer containing urea and phenylboronic acid structural units, denoted as P1.

[0076] Weigh 18.0g of acrylate monomer P1 containing urea and phenylboronic acid structural units and dissolve it in 300mL of water. Then add 0.18g of potassium persulfate to the water to obtain a reaction solution. Stir the above reaction solution at 80℃ for 12 hours to obtain a uniform and stable polymer binder solution, denoted as A1.

[0077] Example 2

[0078] A method for preparing a battery binder includes the following steps:

[0079] Under an argon atmosphere, 6.0 g of acrylate monomer P1 containing urea and phenylboronic acid structural units and 11.98 g of acrylamide monomer (denoted as F1) were weighed and dissolved in 300 mL of water. Then, 0.18 g of potassium persulfate was added to the water to obtain a reaction solution. The above reaction solution was stirred at 80 °C for 12 hours to obtain a homogeneous and stable polymer binder solution, denoted as A2.

[0080] Example 3

[0081] A method for preparing a battery binder includes the following steps:

[0082] Under an argon atmosphere, 3.6 g of acrylate monomer P1 containing urea and phenylboronic acid structural units and 14.4 g of...

[0083] Dissolve (F2) in 300 mL of water, then add 0.18 g of potassium persulfate to the water to obtain a reaction solution; stir the above reaction solution at 80 °C for 12 hours to obtain a uniform and stable polymer binder solution, denoted as A3.

[0084] Example 4

[0085] A method for preparing a battery binder includes the following steps:

[0086] Under an argon atmosphere, 2.57 g of acrylate monomer P1 containing urea and phenylboronic acid structural units and 15.43 g of... Dissolve (F3) in 300 mL of water, then add 0.18 g of potassium persulfate to the water to obtain a reaction solution; stir the above reaction solution at 80 °C for 12 hours to obtain a uniform and stable polymer binder solution, denoted as A4.

[0087] Example 5

[0088] A method for preparing a battery binder includes the following steps:

[0089] Under an argon atmosphere, 4.26 g of acrylate monomer P1 containing urea and phenylboronic acid structural units and 13.74 g of...

[0090]

[0091] Dissolve (F4) in 300 mL of water, then add 0.18 g of potassium persulfate to the water to obtain a reaction solution; stir the above reaction solution at 80 °C for 12 hours to obtain a uniform and stable polymer binder solution, denoted as A5.

[0092] Example 6

[0093] A method for preparing a battery binder includes the following steps:

[0094] Under an argon atmosphere, 1.9 g of acrylate monomer P1 containing urea and phenylboronic acid structural units and 16.1 g of F2 monomer were weighed and dissolved in 300 mL of water. Then, 0.18 g of potassium persulfate was added to the water to obtain a reaction solution. The above reaction solution was stirred at 80 °C for 12 hours to obtain a homogeneous and stable polymer binder solution, denoted as B3.

[0095] Example 7

[0096] A method for preparing a battery binder includes the following steps:

[0097] Under an argon atmosphere, 6.4 g of acrylate monomer P1 containing urea and phenylboronic acid structural units and 11.6 g of F2 monomer were weighed and dissolved in 300 mL of water. Then, 0.18 g of potassium persulfate was added to the water to obtain a reaction solution. The above reaction solution was stirred at 80 °C for 12 hours to obtain a homogeneous and stable polymer binder solution, denoted as C3.

[0098] Example 8

[0099] A method for preparing a battery binder includes the following steps:

[0100] Under an argon atmosphere, 1.2 g of acrylate monomer P1 containing urea and phenylboronic acid structural units and 16.8 g of F2 monomer were weighed and dissolved in 300 mL of water. Then, 0.18 g of potassium persulfate was added to the water to obtain a reaction solution. The above reaction solution was stirred at 80 °C for 12 hours to obtain a homogeneous and stable polymer binder solution, denoted as D3.

[0101] Performance study of the adhesives described in Examples 1-5 of this application:

[0102] The tensile strength of the adhesive is determined according to the tensile test method; the sample is prepared according to the national standard GB / T 1040, with a parallel section size > 20 mm, an aspect ratio of 5:1, and a thickness greater than 1 mm. A static tensile load is applied to the sample to determine the tensile strength.

[0103] The elongation at break of the adhesive was determined according to the tensile test method. Samples were prepared according to the national standard GB / T 1040, with a parallel section >20mm, an aspect ratio of 5:1, and a thickness greater than 1mm. A static tensile load was applied to the sample to determine the elongation at break. The test results are shown in Table 1.

[0104] Table 1

[0105] Example 1 Example 2 Example 3 Example 4 Example 5 Tensile strength (MPa) 8.7 10.2 10.6 11.1 8.3 Elongation at break (%) 150.2 120.5 170.2 140.3 130.5

[0106] As shown in Table 1, the adhesive described in this application has a superior elongation at break. The hydroxyl and amide groups in the monomers of the adhesive described in this application can react with phenylboronic acid groups to form a cross-linked structure, thereby significantly improving the tensile strength of the polymer adhesive. Furthermore, as shown in Table 1, the adhesive prepared in Example 3 of this application has even better elongation at break properties. This is because the polymer adhesive prepared using F2 monomer contains a large number of ester bonds, which can significantly increase the polymer's elasticity.

[0107] The effect of different molar ratios of P1 and F2 on the properties of the prepared adhesive is shown in Table 2.

[0108] Table 2

[0109] Example 3 Example 6 Example 7 Example 8 The molar ratio of P1 to F2 10：90 5：95 20：80 3：97 Tensile strength (MPa) 10.6 10.3 11.2 9.3 Elongation at break (%) 170.2 165.3 143.2 167.4

[0110] This application study investigates the performance of the binders described in Examples 1-5 in batteries.

[0111] The negative electrode active materials, silicon carbide 450 and Super P, were added to a mortar at a mass ratio of 0.94:0.03:0.03 with the binders described in Examples 1-5 and the CMC / SBR binder, respectively. 1.5 mL of deionized water was added as a dispersant. The mixture was ground and stirred at 30°C for 20 minutes to obtain a uniform slurry. This slurry was then uniformly coated onto copper foil, which was then dried in a 60°C oven for 2 hours. The foil was then punched into electrode sheets of suitable size using a punching machine, and further dried in an 80°C oven for 24 hours. The sheets were then stored in a glove box for later use.

[0112] Using the electrodes obtained above as the negative electrode and lithium nickel cobalt manganese oxide as the positive electrode, a lithium nickel cobalt manganese oxide / silicon-carbon 450 full cell was assembled. The long-term cycling performance and capacity retention of the above cell at 0.5C and room temperature were tested, and the results are as follows: Figures 1-6 As shown in Table 3.

[0113] Table 3

[0114] Example 1 Example 2 Example 3 Example 4 Example 5 CMC / SBR Capacity retention 79.6％ 72.1％ 80.5％ 78.1％ 72.7％ 67.8

[0115] From Table 3 and Figure 1-6 It can be seen that the binder prepared in this application can significantly improve the cycle stability of the battery when applied to silicon-based electrode materials. The lithium nickel cobalt manganese oxide / silicon carbon 450 full cell assembled based on the silicon carbon 450 electrode prepared in Example 3 exhibits the best long-cycle performance.

[0116] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A battery adhesive, characterized in that, The raw materials for preparing the battery binder include a first monomer and a second monomer; the first monomer includes an acrylate monomer containing urea and phenylboronic acid structural units; The structural formula of the first monomer is: ； The second monomer includes a functional monomer that can undergo a condensation reaction with phenylboronic acid; The method for preparing the battery binder includes the following steps: polymerizing the raw materials for preparing the battery binder under the action of an initiator; the initiator includes one or more of ammonium persulfate, potassium persulfate, and sodium persulfate; the polymerization temperature is 70-90℃, and the polymerization time is 10-14h.

2. The battery adhesive according to claim 1, characterized in that, The raw materials for preparing the first monomer include isocyanate methacrylate and aminophenylboronic acid; The molar ratio of the isocyanate methacrylate to the aminophenylboronic acid is 1:0.9-1.

5.

3. The battery binder according to claim 1, characterized in that, The second monomer includes acrylic acid, acrylamide, N-hydroxymethylacrylamide, hydroxyl-containing acrylates, , , polyethylene glycol monohydroxy acrylate and One or more of the following; And / or, the molar ratio of the first monomer to the second monomer is (1-99):(1-99).

4. The battery adhesive according to claim 1, characterized in that, The molar ratio of the first monomer to the second monomer is (5-10):(95-90).

5. A method for preparing the battery binder according to any one of claims 1-4, characterized in that, The process includes the following steps: polymerizing the raw materials for preparing the battery binder under the action of an initiator; the initiator includes one or more of ammonium persulfate, potassium persulfate, and sodium persulfate; the polymerization temperature is 70-90℃, and the polymerization time is 10-14h.

6. The method for preparing the battery binder according to claim 5, characterized in that, The amount of the initiator added is 0.5%-1.0% of the total mass of the first monomer and the second monomer.

7. The method for preparing the battery binder according to claim 5, characterized in that, The preparation method further includes preparing the first monomer; The preparation of the first monomer includes the following steps: nucleophilic addition reaction of isocyanate methacrylate and aminophenylboronic acid.

8. The method for preparing the battery binder according to claim 7, characterized in that, The nucleophilic addition reaction is carried out in an organic solvent, which includes one or more of dichloromethane, N,N-dimethylformamide, dimethyl sulfoxide, and ethylene glycol dimethyl ether.

9. The method for preparing the battery binder according to claim 7, characterized in that, The nucleophilic addition reaction is carried out at a temperature of 20-30°C and for a duration of 10-14 hours.

10. A secondary battery, characterized in that, Includes the battery binder according to any one of claims 1-4 or the battery binder obtained by the preparation method according to any one of claims 5-9.

11. The secondary battery according to claim 10, characterized in that, The secondary battery further includes electrode active materials, a conductive agent, and the binder; The mass ratio of the electrode active material, the conductive agent and the binder is (50-95):(2-25):(3-25).

12. The secondary battery according to claim 11, characterized in that, The electrode active material includes a positive electrode active material and a negative electrode active material; The positive electrode active material includes one or more of lithium cobalt oxide, lithium iron manganese phosphate, lithium manganese oxide, lithium iron phosphate, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, sodium vanadium phosphate, lithium-rich manganese-based materials, sodium vanadium fluorinated phosphate, sodium iron pyrophosphate, and sodium nickel iron manganese oxide. The negative electrode active material includes one or more of the following: lithium metal alloy, graphite, nano-silicon, silicon suboxide, and hard carbon. And / or, the conductive agent includes one or more of Super P conductive agent, Ketjen Black, acetylene black and carbon nanotubes.

13. The secondary battery according to claim 10, characterized in that, The secondary battery includes a lithium-ion battery or a sodium-ion battery.

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