Star-shaped polyacrylate emulsion binder, its preparation method and use

Abstract

The present application relates to the technical field of adhesive, and discloses a star-shaped polyacrylate emulsion adhesive, a preparation method and application thereof, wherein the star-shaped polyacrylate emulsion adhesive is obtained by dispersing the star-shaped polyacrylate in water in the form of particles to form a latex, and the structure of the polyacrylate is shown as follows: wherein R1 represents a hydrophilic segment containing a polar group, and the average polymerization degree is 30-250; and the hydrophobic segment with ABA structure or AB structure, wherein A is polymethyl methacrylate or polystyrene, and the average polymerization degree is 100-700; and B is one or more mixed from polyacrylate, polyacrylate, polyacrylate, polyacrylate, polyacrylate and polyacrylate, and the average polymerization degree is 300-800. The adhesive has more branches, more anchor points, can bear greater mechanical stress, has greater adhesion strength, reduces the possibility of adhesive slipping on the surface of active substances, and improves the electrochemical performance of the battery.

Description

Technical Field

[0001] This invention belongs to the technical field of adhesives, and particularly relates to a star-shaped polyacrylate emulsion adhesive, its preparation method, and its application. Background Technology

[0002] Lithium-ion batteries are increasingly widely used in energy storage due to their advantages such as high energy density, environmental friendliness, long lifespan, and light weight. In recent years, with the continuous development of digital products and new energy vehicles, research on lithium-ion batteries has also made great progress, but short battery life and long charging time remain major technical obstacles to their development. Silicon has a theoretical specific capacity as high as 4200 mAh·g. -1 Silicon is considered one of the most promising anode materials to replace graphite. However, silicon undergoes significant volume expansion during the charging and discharging process of lithium-ion batteries, causing the active material to detach from the current collector and resulting in rapid capacity decay. As an electrode component, the binder firmly bonds the active material and conductive agent to the current collector, playing a crucial role in the battery's rate performance and cycle life. Therefore, designing a high-performance binder is an effective method to suppress the volume expansion of silicon materials.

[0003] Polyacrylate binders are widely used as adhesives for battery electrodes due to their excellent film-forming properties, stable electrochemical performance, and resistance to oxidation. Electrodes made with polyacrylate binders exhibit good adhesion and flexibility, and the active material on the electrode surface is less likely to detach, which is beneficial for improving battery capacity. However, commonly used acrylate emulsion binders are mostly linear structures and cannot effectively mitigate the effects of volume changes at silicon-based anodes.

[0004] Therefore, it is essential to provide an adhesive that has more anchoring points, can withstand greater mechanical stress, effectively limits the slippage of the adhesive on the surface of the active material, improves adhesion strength, and enhances the electrochemical performance of the battery. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a star-shaped polyacrylate emulsion binder with a branched structure, which has more anchoring points than linear polymer binders, can withstand greater mechanical stress, can effectively limit the slippage of the binder on the surface of the active material and improve the adhesion strength, and improve the electrochemical performance of the battery, as well as its preparation method and application.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] A star-shaped polyacrylate emulsion binder is obtained by dispersing star-shaped polyacrylate particles in water to form a latex. The structure of the star-shaped polyacrylate is shown below:

[0008]

[0009] Wherein, R1- represents a hydrophilic segment containing a polar group, with an average degree of polymerization of 30-250; This represents a hydrophobic segment with an ABA or AB structure, where A is polymethyl methacrylate or polystyrene with an average degree of polymerization of 100-700, and B is one or more of polyethyl acrylate, polybutyl acrylate, polyisooctyl acrylate, polydodecyl acrylate, and polytetradecyl acrylate with an average degree of polymerization of 300-800.

[0010] A method for preparing a star-shaped polyacrylate emulsion binder includes the following steps:

[0011] Step 1: Weigh 0.5-1.5 parts by weight of macromolecular RAFT reagent, 0.4-1.2 parts by weight of bifunctional crosslinking agent, and 15-30 parts by weight of deionized water, mix them, and react at 60-90℃ for 6-10 hours to obtain star-shaped polymeric emulsifier.

[0012] Step 2: Weigh 1-5 parts by weight of monomer A, 15-50 parts by weight of deionized water and 0.3-1.5 parts by weight of star-shaped polymer emulsifier, mix and emulsify to obtain a pre-emulsion;

[0013] Step 3: Weigh 0.03-0.15 parts by weight of water-soluble initiator, prepare an initiator solution with a mass concentration of 1-2% using deionized water, heat the preemulsion to 60-90°C while stirring, add the initiator solution, and then keep the temperature constant for 60-120 min; then keep the temperature constant and add 4-15 parts by weight of monomer B, and continue the reaction for 60-120 min to obtain the preproduct;

[0014] Step 4: Cool the preproduct from Step 3 to room temperature to obtain... A star-shaped polyacrylate emulsion binder with hydrophobic segments of the AB structure; or, while maintaining the temperature of the preproduct from step 3, adding 1-5 parts by weight of monomer A, and then continuing the reaction for 60-120 minutes, to obtain... A star-shaped polyacrylate emulsion binder with hydrophobic segments of ABA structure;

[0015] The structure of the macromolecular RAFT reagent is as follows:

[0016] Wherein, R is isobutyric acid or 2-acrylonitrile acid; Z is C12 alkylthio or C12 alkyl; R1 is -H or -CH3; R2 is -H or -CH3; when R2 is -H, R3 is -H or -CH2OH; when R2 is -CH3, R3 is -H; m represents the average degree of polymerization of acrylic monomers, m = 15-125; n represents the average degree of polymerization of acrylamide monomers, n = 15-125;

[0017] The bifunctional crosslinking agent is one or more of N,N-methylenebisacrylamide, polyethylene glycol diacrylate, and tetraethylene glycol diacrylate in any proportion;

[0018] The monomer A is either methyl methacrylate or styrene;

[0019] The B monomer is any one or a mixture in any proportion of ethyl acrylate, butyl acrylate, isooctyl acrylate, dodecyl acrylate and tetradecyl acrylate;

[0020] The water-soluble initiator is potassium persulfate or ammonium persulfate.

[0021] Furthermore, in step 1, the macromolecular RAFT reagent, the bifunctional crosslinking agent, and deionized water are mixed in a reactor equipped with a condenser.

[0022] Furthermore, in step 3, the preemulsion is stirred and heated in a reactor equipped with a stirrer and a condenser.

[0023] Application of the above-mentioned star-shaped polyacrylate emulsion binder in silicon-based anodes of lithium-ion batteries.

[0024] Compared with the prior art, the present invention has the following technical effects:

[0025] The polyacrylate emulsion binder of this invention has a star-shaped structure with more branched chains, increasing the binding sites between the binder and the active material. This improves the adhesion strength between the binder and the active material, enhancing the structural stability of the electrode. Therefore, compared to linear polymer binders, the star-shaped polyacrylate emulsion binder of this invention has more branched chains, more anchoring points, and can withstand greater mechanical stress, effectively limiting the slippage of the binder on the surface of the active material and improving adhesion strength and the electrochemical performance of the battery. Furthermore, the polyacrylate emulsion binder of this invention uses water as a solvent, offering advantages of safety and environmental friendliness, and is relatively low in cost.

[0026] In the preparation method of the star-shaped polyacrylate emulsion binder of the present invention, a macromolecular RAFT reagent containing carboxyl and amide groups is used as the polymer arm, and a monomer containing divinyl functional groups is used as the crosslinking agent. A high molecular weight emulsifier with a star-shaped structure is prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization. The star-shaped polyacrylate emulsion binder is then prepared by RAFT soap-free emulsion polymerization technology. This technology has high monomer conversion rate, mild polymerization conditions, controllable molecular weight of the product, and narrow molecular weight distribution. Therefore, the prepared star-shaped polyacrylate binder has good stability and a narrow particle size distribution of latex particles.

[0027] Furthermore, the amide groups or ether bonds contained in the bifunctional crosslinking agent used in the preparation method can form a large number of hydrogen bonds with silicon particles, thereby improving the adhesion strength of the binder. At the same time, the abundant N and O atoms in the crosslinking agent can promote chelation with lithium ions, which is beneficial to the transport and storage of lithium ions and improves the specific capacity of the battery.

[0028] The star-shaped polyacrylate emulsion binder prepared in this invention, when applied to the silicon-based anode of lithium-ion batteries, can effectively reduce the possibility of the active material detaching from the current collector and the capacity rapidly decaying due to the huge volume expansion of silicon in the anode during the charging and discharging process of lithium-ion batteries, thus effectively improving the electrochemical performance of lithium-ion batteries. Attached Figure Description

[0029] Figure 1 This is a peel strength test diagram of the star-shaped polyacrylate emulsion binder used as a silicon-oxygen anode in Embodiment 5 of the present invention.

[0030] Figure 2 This is a mechanical strength diagram of the star-shaped polyacrylate emulsion binder in Example 5 of the present invention;

[0031] Figure 3 This is the first charge-discharge curve of the star-shaped polyacrylate emulsion binder in Example 5 of the present invention. Detailed Implementation

[0032] The specific content of the present invention will be further explained in detail below with reference to the embodiments.

[0033] In the star-shaped polyacrylate emulsion binder of the present invention, R1- in the polyacrylate structure represents a hydrophilic segment containing a polar group, and the polar group is a polar group such as a carboxyl group and an amide group.

[0034] Example

[0035] Example 1

[0036] A method for preparing a star-shaped polyacrylate emulsion binder includes the following steps:

[0037] Step 1: Weigh 0.7 parts by weight of macromolecular RAFT reagent, 1.0 parts by weight of bifunctional crosslinking agent, and 20 parts by weight of deionized water, mix them in a reactor equipped with a condenser, and react at 90°C for 8 hours to obtain star-shaped polymeric emulsifier.

[0038] Step 2: Weigh 2 parts of monomer A, 35 parts of deionized water and 0.5 parts of star-shaped polymer emulsifier, mix and emulsify to obtain a pre-emulsion;

[0039] Step 3: Weigh 0.08 parts by weight of water-soluble initiator and prepare an initiator solution with a mass concentration of 2% using deionized water. Add the preemulsion to a reactor equipped with a stirrer and a condenser. While stirring, heat to 80°C and then add the initiator solution. Keep the temperature constant and react for 120 min. Then, keep the temperature constant and add 5 parts by weight of monomer B. Continue the reaction for 120 min to obtain the preproduct.

[0040] Step 4: Cool the preproduct from Step 3 to room temperature to obtain... It is a star-shaped polyacrylate emulsion binder with an AB structure of hydrophobic segments.

[0041] In this mixture, monomer A is methyl methacrylate; monomer B is a mixture of ethyl acrylate, butyl acrylate, and isooctyl acrylate in a weight ratio of 1:1:1; the water-soluble initiator is potassium persulfate; and the bifunctional crosslinking agent is N,N-methylenebisacrylamide.

[0042] Example 2

[0043] A method for preparing a star-shaped polyacrylate emulsion binder includes the following steps:

[0044] Step 1: Weigh 0.8 parts by weight of macromolecular RAFT reagent, 1.0 parts by weight of bifunctional crosslinking agent, and 30 parts by weight of deionized water, mix them in a reactor equipped with a condenser, and react at 90°C for 10 hours to obtain star-shaped polymeric emulsifier.

[0045] Step 2: Weigh 2 parts by weight of monomer A, 40 parts by weight of deionized water and 1.0 part by weight of star-shaped polymer emulsifier, mix and emulsify to obtain a pre-emulsion;

[0046] Step 3: Weigh 0.15 parts by weight of water-soluble initiator and prepare an initiator solution with a mass concentration of 2% using deionized water. Add the preemulsion to a reactor equipped with a stirrer and a condenser. While stirring, heat to 80°C and then add the initiator solution. Keep the temperature constant and react for 120 min. Then, keep the temperature constant and add 10 parts by weight of monomer B. Continue the reaction for 120 min to obtain the preproduct.

[0047] Step 4: While maintaining the temperature of the preproduct from Step 3, add 5 parts by weight of monomer A, and continue the reaction for 90 minutes to obtain... It is a star-shaped polyacrylate emulsion binder with hydrophobic segments of ABA structure.

[0048] In this mixture, monomer A is styrene; monomer B is a mixture of dodecyl acrylate and tetradecyl acrylate in a weight ratio of 2:1; the water-soluble initiator is ammonium persulfate; and the bifunctional crosslinking agent is polyethylene glycol diacrylate.

[0049] Example 3

[0050] A method for preparing a star-shaped polyacrylate emulsion binder includes the following steps:

[0051] Step 1: Weigh 0.5 parts by weight of macromolecular RAFT reagent, 1.0 parts by weight of bifunctional crosslinking agent, and 30 parts by weight of deionized water, mix them in a reactor equipped with a condenser, and react at 90°C for 10 hours to obtain star-shaped polymeric emulsifier.

[0052] Step 2: Weigh 5 parts by weight of monomer A, 30 parts by weight of deionized water and 0.8 parts by weight of star-shaped polymer emulsifier, mix and emulsify to obtain a pre-emulsion;

[0053] Step 3: Weigh 0.10 parts by weight of water-soluble initiator and prepare an initiator solution with a mass concentration of 2% using deionized water. Add the preemulsion to a reactor equipped with a stirrer and a condenser. While stirring, heat to 90°C and then add the initiator solution. Keep the temperature constant and react for 120 min. Then, keep the temperature constant and add 5 parts by weight of monomer B. Continue the reaction for 120 min to obtain the preproduct.

[0054] Step 4: Cool the preproduct from Step 3 to room temperature to obtain... It is a star-shaped polyacrylate emulsion binder with an AB structure of hydrophobic segments.

[0055] In this mixture, monomer A is styrene; monomer B is ethyl acrylate; the water-soluble initiator is potassium persulfate; and the bifunctional crosslinking agent is tetraethylene glycol diacrylate.

[0056] Example 4

[0057] A method for preparing a star-shaped polyacrylate emulsion binder includes the following steps:

[0058] Step 1: Weigh 1.0 parts by weight of macromolecular RAFT reagent, 1.2 parts by weight of bifunctional crosslinking agent, and 30 parts by weight of deionized water, mix them in a reactor equipped with a condenser, and react at 90°C for 10 hours to obtain star-shaped polymeric emulsifier.

[0059] Step 2: Weigh 3 parts by weight of monomer A, 40 parts by weight of deionized water and 1.5 parts by weight of star-shaped polymer emulsifier, mix and emulsify to obtain a pre-emulsion;

[0060] Step 3: Weigh 0.15 parts by weight of water-soluble initiator and prepare an initiator solution with deionized water at a mass concentration of 2%. Add the pre-emulsion to a reactor equipped with a stirrer and a condenser. While stirring, heat to 70°C and then add the initiator solution. Then keep the temperature constant and react for 120 min. After that, keep the temperature constant and add 9 parts by weight of monomer B. Continue to react for 120 min to obtain the pre-product.

[0061] Step 4: Cool the preproduct from Step 3 to room temperature to obtain... It is a star-shaped polyacrylate emulsion binder with an AB structure of hydrophobic segments.

[0062] In this mixture, monomer A is methyl methacrylate; monomer B is butyl acrylate; the water-soluble initiator is ammonium persulfate; and the bifunctional crosslinking agent is a mixture of N,N-methylenebisacrylamide, polyethylene glycol diacrylate, and tetraethylene glycol diacrylate in a weight ratio of 1:1:1.

[0063] Example 5

[0064] A method for preparing a star-shaped polyacrylate emulsion binder includes the following steps:

[0065] Step 1: Weigh 1.0 parts by weight of macromolecular RAFT reagent, 1.2 parts by weight of bifunctional crosslinking agent, and 20 parts by weight of deionized water, mix them in a reactor equipped with a condenser, and react at 90°C for 10 hours to obtain star-shaped polymeric emulsifier.

[0066] Step 2: Weigh 4 parts by weight of monomer A, 50 parts by weight of deionized water and 0.9 parts by weight of star-shaped polymer emulsifier, mix and emulsify to obtain a pre-emulsion;

[0067] Step 3: Weigh 0.10 parts by weight of water-soluble initiator and prepare an initiator solution with deionized water at a mass concentration of 2%. Add the preemulsion to a reactor equipped with a stirrer and a condenser. While stirring, heat to 80°C and then add the initiator solution. Then keep the temperature constant and react for 120 min. After that, keep the temperature constant and add 6 parts by weight of monomer B. Continue to react for 120 min to obtain the preproduct.

[0068] Step 4: While maintaining the temperature of the preproduct from Step 3, add 4 parts by weight of monomer A, and continue the reaction for 120 minutes to obtain... It is a star-shaped polyacrylate emulsion binder with hydrophobic segments of ABA structure.

[0069] Among them, monomer A is methyl methacrylate; monomer B isooctyl acrylate; the water-soluble initiator is potassium persulfate; and the bifunctional crosslinking agent is N,N-methylenebisacrylamide.

[0070] The star-shaped polyacrylate emulsion binder prepared in Example 5 was used as a silicone anode binder, and a peel test was performed on it according to the national standard GB / T 2792-2014. The results are as follows: Figure 1 As shown, the average peel force of the star-shaped polyacrylate adhesive in this embodiment can reach 0.8N, which is 4 times higher than that of the linear polyacrylate, indicating that the star-shaped polyacrylate adhesive prepared in Example 5 has good adhesion strength.

[0071] The star-shaped polyacrylate emulsion binder prepared in Example 5 was formed into a film at room temperature, and its mechanical strength was tested. The results are as follows: Figure 2 As shown, compared to linear polyacrylate, the star-shaped polyacrylate binder in this embodiment exhibits a significantly improved mechanical strength, reaching 7.43 MPa. The higher mechanical strength of the binder helps buffer the mechanical stress generated by large volume changes, maintaining the integrity of the electrode structure.

[0072] The star-shaped polyacrylate emulsion binder prepared in Example 5 was used as a silicon-oxygen anode binder to prepare a lithium-ion battery, and its electrochemical performance was tested at 25°C. Figure 3 The image shows the initial charge-discharge curve of the prepared battery at a 0.1C rate. In this embodiment, the initial discharge capacity of the battery prepared with the star-shaped polyacrylate binder is 517.2 mAh·g. -1 It represents a significant improvement compared to linear polyacrylates.

[0073] Example 6

[0074] A method for preparing a star-shaped polyacrylate emulsion binder includes the following steps:

[0075] Step 1: Weigh 1.5 parts by weight of macromolecular RAFT reagent, 0.4 parts by weight of bifunctional crosslinking agent, and 15 parts by weight of deionized water, mix them in a reactor equipped with a condenser, and react at 60°C for 6 hours to obtain star-shaped polymeric emulsifier.

[0076] Step 2: Weigh 1 part by weight of monomer A, 15 parts by weight of deionized water and 0.3 parts by weight of star-shaped polymer emulsifier, mix and emulsify to obtain a pre-emulsion;

[0077] Step 3: Weigh 0.03 parts by weight of water-soluble initiator and prepare an initiator solution with deionized water at a mass concentration of 1%. Add the pre-emulsion to a reactor equipped with a stirrer and a condenser. While stirring, heat to 60°C and then add the initiator solution. Then keep the temperature constant and react for 60 minutes. After that, keep the temperature constant and add 4 parts by weight of monomer B. Continue to react for 60 minutes to obtain the pre-product.

[0078] Step 4: While maintaining the temperature of the preproduct from Step 3, add 1 part by weight of monomer A, and continue the reaction for 60 minutes to obtain... It is a star-shaped polyacrylate emulsion binder with hydrophobic segments of ABA structure.

[0079] In this mixture, monomer A is styrene; monomer B is dodecyl acrylate; the water-soluble initiator is ammonium persulfate; and the bifunctional crosslinking agent is polyethylene glycol diacrylate.

[0080] Example 7

[0081] A method for preparing a star-shaped polyacrylate emulsion binder includes the following steps:

[0082] Step 1: Weigh 1.5 parts by weight of macromolecular RAFT reagent, 0.4 parts by weight of bifunctional crosslinking agent, and 15 parts by weight of deionized water, mix them in a reactor equipped with a condenser, and react at 80°C for 6 hours to obtain star-shaped polymeric emulsifier.

[0083] Step 2: Weigh 1 part by weight of monomer A, 15 parts by weight of deionized water and 0.3 parts by weight of star-shaped polymer emulsifier, mix and emulsify to obtain a pre-emulsion;

[0084] Step 3: Weigh 0.03 parts by weight of water-soluble initiator and prepare an initiator solution with deionized water at a mass concentration of 1%. Add the pre-emulsion to a reactor equipped with a stirrer and a condenser. While stirring, heat to 60°C and then add the initiator solution. Then keep the temperature constant and react for 90 minutes. After that, keep the temperature constant and add 15 parts by weight of monomer B. Continue to react for 90 minutes to obtain the pre-product.

[0085] Step 4: Cool the preproduct from Step 3 to room temperature to obtain... It is a star-shaped polyacrylate emulsion binder with an AB structure of hydrophobic segments.

[0086] In this mixture, monomer A is methyl methacrylate; monomer B is tetradecyl acrylate; the water-soluble initiator is potassium persulfate; and the bifunctional crosslinking agent is a mixture of N,N-methylenebisacrylamide and tetraethylene glycol diacrylate in a mass ratio of 2:1.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A star-shaped polyacrylate emulsion binder, characterized in that: The product is obtained by dispersing star-shaped polyacrylate particles in water to form a latex. The star-shaped structure is formed by reacting a macromolecular RAFT reagent with a bifunctional crosslinking agent to form a star-shaped polymeric emulsifier, which is then further polymerized with a hydrophobic monomer to form a star-shaped polyacrylate emulsion binder. A method for preparing a star-shaped polyacrylate emulsion binder includes the following steps: Step 1: Weigh 0.5-1.5 parts by weight of macromolecular RAFT reagent, 0.4-1.2 parts by weight of bifunctional crosslinking agent, and 15-30 parts by weight of deionized water, mix them, and react at 60-90℃ for 6-10 h to obtain star-shaped polymeric emulsifier. Step 2: Weigh 1-5 parts by weight of monomer A, 15-50 parts by weight of deionized water and 0.3-1.5 parts by weight of star-shaped polymer emulsifier, mix and emulsify to obtain a pre-emulsion; Step 3: Weigh 0.03-0.15 parts by weight of water-soluble initiator, prepare an initiator solution with a mass concentration of 1-2% using deionized water, heat the preemulsion to 60-90°C while stirring, add the initiator solution, and then keep the temperature constant for 60-120 min; then keep the temperature constant and add 4-15 parts by weight of monomer B, and continue the reaction for 60-120 min to obtain the preproduct; Step 4: Cool the preproduct from Step 3 to room temperature to obtain a star-shaped polyacrylate emulsion binder with hydrophobic segments of AB structure; or keep the preproduct from Step 3 at a constant temperature and add 1-5 parts by weight of monomer A, and then continue the reaction for 60-120 min to obtain a star-shaped polyacrylate emulsion binder with hydrophobic segments of ABA structure. The structure of the macromolecular RAFT reagent is as follows: ; Wherein, R is isobutyric acid or 2-acrylonitrile acid; Z is C12 alkylthio or C12 alkyl; R1 is -H or -CH3; R2 is -H or -CH3; when R2 is -H, R3 is -H or -CH2OH; when R2 is -CH3, R3 is -H; m represents the average degree of polymerization of acrylic monomers, m=15-125; n represents the average degree of polymerization of acrylamide monomers, n=15-125; The bifunctional crosslinking agent is one or more of N,N-methylenebisacrylamide, polyethylene glycol diacrylate, and tetraethylene glycol diacrylate in any proportion; The monomer A is either polymethyl methacrylate or polystyrene, with an average degree of polymerization of 100-700. The B monomer is any one or a mixture in any proportion of ethyl polyacrylate, butyl polyacrylate, isooctyl polyacrylate, dodecyl polyacrylate, and tetradecyl polyacrylate, with an average degree of polymerization of 300-800. The water-soluble initiator is potassium persulfate or ammonium persulfate.

2. The star-shaped polyacrylate emulsion binder as described in claim 1, characterized in that, In step 1, the macromolecular RAFT reagent, the bifunctional crosslinking agent, and deionized water are mixed in a reactor equipped with a condenser.

3. The star-shaped polyacrylate emulsion binder as described in claim 1, characterized in that, In step 3, the preemulsion is stirred and heated in a reactor equipped with a stirrer and a condenser.

4. The application of a star-shaped polyacrylate emulsion binder as described in claim 1 in a silicon-based anode of a lithium-ion battery.

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