Lithium negative electrode slurry and homogenizing process thereof

Abstract

The application provides a lithium negative electrode slurry and a homogenizing process thereof. The negative electrode slurry comprises graphite, a conductive agent, a binder, a thickening agent and a solvent. The conductive agent comprises at least one of carbon nanotubes, conductive carbon black and graphene. The thickening agent comprises sodium carboxymethyl cellulose. The binder comprises PAA or a water-based binder copolymerized with PAA, and butadiene styrene rubber. The solvent is deionized water. The total solid content of the negative electrode slurry is 46-50%, and the initial viscosity is 2500-4000 mPa.S. The negative electrode slurry is prepared by combining dry and wet methods. The application has the advantages that carbon nanotubes, carbon black and graphene can be effectively used as the negative electrode composite conductive agent in the water-based negative electrode slurry, the negative electrode slurry has good dispersion effect, good stability, good coating performance and is not prone to delamination, and the negative electrode plate can be effectively improved in resistivity, reduced in impedance, improved in energy density of the battery cell and increased in liquid retention.

Description

Technical Field

[0001] This invention belongs to the field of electrode materials, and particularly relates to a lithium battery negative electrode slurry and its homogenization process. Background Technology

[0002] Lithium-ion batteries are widely used in consumer electronics, energy storage, and power batteries due to their high operating voltage, high specific energy, low self-discharge, and good cycle performance.

[0003] Conductive agents in lithium-ion batteries, as key auxiliary materials for achieving conductivity, are divided into traditional conductive agents (conductive graphite, conductive carbon black, carbon fiber) and novel conductive agents (carbon nanotubes, graphene). Commonly used traditional conductive agents, such as conductive carbon black, have point-to-point contact with the active material, while novel conductive agents, such as carbon nanotubes (CNTs), can have point-to-line contact with the active material. They exhibit excellent electrical and thermal conductivity, significantly contributing to improved battery capacity, rate performance, cycle life, and reduced battery polarization. They also facilitate heat dissipation during charging and discharging.

[0004] Novel conductive agents, such as graphene, utilize a unique sheet-like structure, resulting in point-to-surface contact with active materials. This maximizes the effectiveness of the conductive agent while reducing its dosage. Therefore, combining two or all three of CNTs, graphene, and conductive carbon black to create conductive pastes can fully leverage the synergistic effects between the conductive agents. This approach is more suitable for use in lithium-ion battery cathodes with poor conductivity, forming a robust conductive network. Currently, some composite oil-based conductive pastes are already being used in lithium-ion battery cathodes.

[0005] For lithium-ion battery anode materials, although the commonly used graphite anode material has good conductivity, the expansion and contraction of the graphite material during repeated charge and discharge processes reduces the contact between graphite particles, increases the gaps, and some even detach from the current collector and no longer participate in the electrode reaction. Therefore, it is necessary to add a conductive agent to maintain the stability of the material's conductivity during cycling.

[0006] Currently, conductive carbon black is still the main conductive agent used in negative electrodes because it has the best dispersibility in aqueous negative electrode slurries. However, as the power market places increasingly stringent demands on the performance of lithium-ion batteries (energy density, cycle life, fast charging performance), constructing a better conductive network, reducing the amount of conductive agent used, and reducing the battery interface impedance are the most direct ways to solve these problems. The development and application of novel aqueous negative electrode composite conductive agents is a new approach.

[0007] The dispersion effect of the negative electrode slurry in aqueous negative electrode directly affects the processing performance, capacity utilization, internal resistance, rate performance, etc. of lithium-ion batteries. New conductive agents generally have a large specific surface area, and it is already difficult to disperse them when used alone. Using them in combination will further increase the difficulty of dispersing the negative electrode slurry. Conventional dry or wet slurry homogenization processes cannot achieve a good dispersion effect. Summary of the Invention

[0008] To address the problem that novel conductive agents are difficult to disperse in aqueous negative electrode slurries in existing technologies, which affects the processing performance, capacity utilization, internal resistance, and rate performance of lithium-ion batteries, this invention provides a lithium battery negative electrode slurry and its homogenization process.

[0009] The technical solution of the present invention is as follows: a lithium battery anode slurry, comprising graphite, a conductive agent, a binder, a thickener, and a solvent; the conductive agent includes at least one of carbon nanotubes, conductive carbon black, and graphene; the thickener includes sodium carboxymethyl cellulose; the binder includes water-based binders such as PAA or its copolymers, and styrene-butadiene rubber; the solvent is deionized water; the total solid content of the lithium battery anode slurry is 46-50%, and the initial viscosity is 2500-4000 mPa·s.

[0010] Furthermore, the aqueous binders of PAA or its copolymers include at least one of LA136D and LB300.

[0011] Furthermore, in the lithium-ion battery anode slurry, the solutes, by mass percentage, comprise 95–97% graphite, 0.5%–1.5% conductive agent, 1.4%–2.3% binder, and 0.8%–1.6% thickener.

[0012] Furthermore, the conductive agent contains, by mass percentage, 40-60% conductive carbon black, 30-50% carbon nanotubes (CNTs), and 0-20% graphene.

[0013] Furthermore, the adhesive contains 0% to 1% waterborne PAA or its copolymers, and 1% to 2% styrene-butadiene rubber.

[0014] The present invention also provides a homogenization process for lithium battery anode slurry to prepare the above-mentioned lithium battery anode slurry, comprising the following steps:

[0015] S1. Preparation of composite conductive slurry: After mixing the conductive agent, dispersant and deionized water, disperse them in a stirrer to obtain a composite conductive slurry for later use;

[0016] S2. Preparation of thickening solution: Sodium carboxymethyl cellulose is added to deionized water and dispersed by stirring in a planetary mixer to prepare a thickening solution with a solid content of 1-2%.

[0017] S3. Preparation of the first adhesive solution: Add PAA or its copolymer water-based binder with a solid content of 40% to the thickening liquid, further disperse to obtain the first adhesive solution, and take out 40-50% of the first adhesive solution for later use.

[0018] S4. Preparation of conductive adhesive solution: Add the composite conductive slurry from step S1 to the remaining first adhesive solution and disperse it again to obtain a conductive adhesive solution for later use.

[0019] S5. Graphite wetting: Add deionized water to the graphite for wetting and stir to disperse; the amount of deionized water is 20-30% of the graphite mass;

[0020] S6. Preparation of the first composite slurry: Add the conductive adhesive solution from step S4 to the stirring tank that wets the graphite in step S5, adjust the solid content of the composite slurry to 65-70%, and stir to disperse.

[0021] S7. Preparation of the second composite slurry: Add the first adhesive liquid prepared in step S3 to the slurry in step S6, and add deionized water to disperse it evenly. Vacuum is drawn during the dispersion process to obtain the second composite slurry.

[0022] S8. Preparation of the third composite slurry: Adjust the viscosity of the second composite slurry in step S7, add deionized water, stir and disperse, and vacuum during the dispersion process to obtain the third composite slurry.

[0023] S9. Preparation of lithium battery negative electrode slurry: Add styrene-butadiene rubber solution to the third composite slurry, stir and disperse, vacuum during dispersion, and finally reverse vacuum defoaming to obtain lithium-ion battery negative electrode slurry.

[0024] Furthermore, in step S5, the planetary mixer is first rotated at 15-20 rpm and stirred for 10 minutes, then scraped. After that, the mixture is stirred at 15-25 rpm, dispersed at 200-300 rpm, and stirred for 30-40 minutes.

[0025] Furthermore, in step S6, the composite slurry is first stirred at a revolution speed of 15-20 rpm for 10 minutes and then scraped. After that, it is stirred at a revolution speed of 15-25 rpm and a dispersion speed of 500-600 rpm for 70-90 minutes, and the cooling water circulation system is turned on during the stirring process.

[0026] Further, in step S7, the composite slurry is first stirred at a revolution speed of 15-20 rpm and a dispersion speed of 800-1000 rpm for 10 minutes and then scraped; then it is stirred at a revolution speed of 25-35 rpm and a dispersion speed of 2500-3500 rpm for 60-90 minutes, with a vacuum degree of -88 kPa to -92 kPa during the dispersion process, to obtain the second composite slurry.

[0027] The advantages of this invention are: it combines the advantages of dry pulping and wet pulping, and can effectively use carbon nanotubes, carbon black and graphene as composite conductive agents in aqueous negative electrode slurry, resulting in a negative electrode slurry with good dispersion, good stability, good coating performance and less delamination. It can also effectively improve the resistivity of the negative electrode sheet, reduce impedance, increase the energy density of the cell and increase the liquid retention. Attached Figure Description

[0028] Figure 1 This is a process diagram of homogenizing lithium battery negative electrode slurry according to the present invention. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] The lithium-ion battery anode slurry of the present invention comprises graphite, a conductive agent, a binder, a thickener, and a solvent. The conductive agent includes carbon nanotubes (CNT), conductive carbon black, and graphene; the thickener includes sodium carboxymethyl cellulose (CMC); the binder includes aqueous binders of PAA or its copolymers (LA136D or LB300) and styrene-butadiene rubber (SBR); the solvent is deionized water; the total solid content of the anode slurry is 46-50%, and the initial viscosity is 2500-4000 mPa·s.

[0031] In the lithium-ion battery anode slurry, the solutes, by mass percentage, are: graphite 95-97%, conductive agent 0.5%-1.5%, binder 1.4-2.3%, and thickener 0.8-1.6%.

[0032] The conductive agent comprises, by mass percentage: 40% conductive carbon black, 30-50% carbon nanotubes (CNTs), and 0-20% graphene.

[0033] The adhesive contains 0%–1% waterborne PAA or its copolymers, and 1%–2% styrene-butadiene rubber.

[0034] like Figure 1 As shown, the lithium battery anode slurry homogenization process of the present invention includes the following steps:

[0035] S1. Preparation of composite conductive slurry: After mixing the components of the conductive agent, deionized water and dispersant are added, and the mixture is stirred to pre-disperse the composite conductive slurry for later use.

[0036] S2. Preparation of thickening liquid: Sodium carboxymethyl cellulose (CMC) is added to deionized water and stirred and dispersed in a planetary mixer at a rotation speed of 20-35 rpm and a dispersion speed of 2000-3000 rpm for 90-150 min to prepare a thickening liquid with a solid content of 1-2%.

[0037] S3. Preparation of the first adhesive solution: Add 40% solids content PAA or its copolymer water-based binder (LA136D or LB300) to the thickening liquid, further disperse for 30-40 minutes, with a revolution speed of 20-35 rpm and a dispersion speed of 2000-3000 rpm; obtain the first adhesive solution, and take out 40-50% of the first adhesive solution for later use;

[0038] S4. Preparation of conductive adhesive solution: Add the composite conductive slurry from step S1 to the remaining first adhesive solution, and disperse it again at a revolution speed of 25-35 rpm and a dispersion speed of 2500-3500 rpm for 90-120 min to obtain the conductive adhesive solution for later use.

[0039] S5. Graphite wetting: Add deionized water to the graphite for wetting. In a planetary mixer, first rotate at 15-20 rpm and stir for 10 minutes, then scrape the material. After that, rotate at 15-25 rpm, disperse at 200-300 rpm, and stir for 30-40 minutes. The amount of deionized water used is 20-30% of the graphite mass.

[0040] S6. Preparation of the first composite slurry: Add the conductive adhesive solution from step S4 to the mixing tank that wets the graphite in step S5, and adjust the solid content of the composite slurry to 65-70%, so that it is in the form of mud; first, stir at a revolution speed of 15-20 rpm for 10 minutes and then scrape the material, and then stir at a revolution speed of 15-25 rpm and a dispersion speed of 500-600 rpm for 70-90 minutes, and turn on the cooling water circulation system during the stirring process;

[0041] S7. Preparation of the second composite slurry: Add the first adhesive solution prepared in step S3 to the slurry in step S6, and add an appropriate amount of deionized water for uniform dispersion. First, stir at a revolution speed of 15-20 rpm and a dispersion speed of 800-1000 rpm for 10 minutes, then scrape the material. Next, stir at a revolution speed of 25-35 rpm and a dispersion speed of 2500-3500 rpm for 60-90 minutes. During the dispersion process, a vacuum is drawn with a vacuum degree of -88 kPa to -92 kPa to obtain the second composite slurry.

[0042] S8. Preparation of the third composite slurry: Adjust the viscosity of the second composite slurry in step S7, add deionized water, stir for 30 minutes at a revolution speed of 25-35 rpm and a dispersion speed of 2500-3500 rpm, and apply vacuum during the dispersion process to a vacuum degree of -88 kPa to -92 kPa to obtain the third composite slurry.

[0043] S9. Preparation of lithium battery negative electrode slurry: Add styrene-butadiene rubber (SBR) solution to the third composite slurry, rotate at 15-20 rpm, disperse at 500-600 rpm, stir for 30 min, vacuum during dispersion, vacuum degree -88 kPa to -92 kPa, and finally reverse vacuum defoaming to obtain lithium-ion battery negative electrode slurry.

[0044] In the preparation process of the above-mentioned lithium battery anode slurry, there are no specific limitations on the proportions of materials not described in each step, as long as the content of each solute in the final slurry reaches the aforementioned mass percentage range. For example, adjusting the solid content of the composite slurry to 65-70% in step S6 can be done by adjusting the solid content of the conductive adhesive in the early stage, or by directly adding a certain amount of deionized water in step S6.

[0045] The rotational speed, dispersion speed, stirring time, vacuum degree, and other conditions of the stirring in each step can be adjusted in a timely manner according to the specific type of planetary stirrer or the difference in the viscosity of the slurry in each step, based on the experience of those skilled in the art. The purpose is to ensure that the slurry in each step is completely and uniformly dispersed. The range given in this invention is a relatively suitable preparation condition in the experiment, but it should not be regarded as a strict limitation on this condition.

[0046] Compared to the traditional wet-process negative electrode slurry preparation method that directly adds conductive agents and graphite to the adhesive solution, the homogenization process of this invention adopts the method of first preparing a composite conductive slurry separately, and then gradually adding the conductive adhesive solution and adhesive solution to wet the graphite. This achieves a gradual reduction in the solid content of the negative electrode slurry and better dispersion effect, and is especially suitable for the use of composite conductive agents in negative electrode slurries.

[0047] The present invention will be further illustrated below with two specific embodiments.

[0048] Example 1

[0049] The homogenization process for lithium-ion battery anode slurry includes the following steps:

[0050] S1. Preparation of composite conductive paste: Carbon nanotubes (CNT), conductive carbon black, and graphene are mixed, and deionized water and dispersant are added for pre-dispersion, wherein CNT:SP:graphene = 4:5:1, to obtain a composite conductive paste with an effective content of 5% for later use. The mass ratio of the composite conductive agent to the solute in the negative electrode paste is 0.5%.

[0051] S2. Preparation of thickening solution: Sodium carboxymethyl cellulose (CMC) is added to deionized water and stirred and dispersed in a planetary mixer at a rotation speed of 35 rpm and a dispersion speed of 3000 rpm for 120 min to prepare a thickening solution with a solid content of 1.5%.

[0052] S3. Preparation of the first adhesive solution: Add LB300 with a solid content of 40% to the thickening liquid and further disperse for 40 minutes to obtain the first adhesive solution. Take out 40% of the first adhesive solution and store it for later use.

[0053] S4. Preparation of conductive adhesive solution: Add the composite conductive slurry from step S1 to the remaining first adhesive solution, disperse again for 120 min, and obtain conductive adhesive solution for later use;

[0054] S5. Graphite wetting: Add deionized water to the graphite for wetting, and stir in a planetary mixer for 30 minutes; the amount of deionized water is 22% of the graphite.

[0055] S6. Preparation of the first composite slurry: Add the conductive adhesive liquid from step S4 to the stirring tank that wets the graphite in step S5, adjust the solid content of the composite slurry to 68%, and make it into a mud-like state; first, stir at a revolution speed of 15 rpm for 10 minutes and then scrape the material, then stir at a revolution speed of 20 rpm and a dispersion speed of 600 rpm for 90 minutes, and turn on the cooling water circulation system during the stirring process.

[0056] S7. Preparation of the second composite slurry: Add the first adhesive solution prepared in step S3 to the slurry in step S6, and add an appropriate amount of deionized water for uniform dispersion. First, stir at a revolution speed of 15 rpm and a dispersion speed of 800 rpm for 10 minutes and then scrape the material. Then, stir at a revolution speed of 30 rpm and a dispersion speed of 3200 rpm for 60 minutes. During the dispersion process, a vacuum is drawn with a vacuum degree of -88 kPa to -92 kPa to obtain the second composite slurry.

[0057] S8. Preparation of the third composite slurry: Adjust the viscosity of the second composite slurry in step S7, add a certain amount of deionized water, stir for 30 min at a revolution speed of 30 rpm and a dispersion speed of 3200 rpm, and apply vacuum during the dispersion process to a vacuum degree of -88 kPa to -92 kPa to obtain the third composite slurry.

[0058] S9. Preparation of lithium battery negative electrode slurry: Add styrene-butadiene rubber (SBR) solution to the third composite slurry, rotate at 20 rpm, disperse at 500 rpm, stir for 30 min, vacuum during dispersion, vacuum degree -88 kPa to -92 kPa, and finally reverse vacuum defoaming to obtain lithium-ion battery negative electrode slurry.

[0059] The lithium battery slurry prepared above was uniformly coated on the negative electrode current collector, and after drying and rolling, lithium titanate negative electrode sheet was obtained. Its electrical properties such as resistivity and internal resistance were tested.

[0060] Example 2

[0061] The homogenization process for lithium-ion battery anode slurry includes the following steps:

[0062] S1. Preparation of thickening solution: Sodium carboxymethyl cellulose (CMC) is added to deionized water and stirred and dispersed in a planetary mixer at a rotation speed of 35 rpm and a dispersion speed of 3000 rpm for 120 min to prepare a thickening solution with a solid content of 1.5%.

[0063] S2. Preparation of the first adhesive solution: Add LB300 with a solid content of 40% to the thickening liquid and further disperse for 40 minutes to obtain the first adhesive solution. Take out 40% of the first adhesive solution and store it for later use.

[0064] S3. Preparation of conductive adhesive solution: Add conductive agent SP to the remaining first adhesive solution and disperse at high speed for 120 min to obtain conductive adhesive solution for later use; the mass percentage of conductive agent SP in the negative electrode slurry solute is 1%;

[0065] S4. Graphite wetting: Add deionized water to the graphite for wetting, and stir in a planetary mixer for 30 minutes; the amount of deionized water is 22% of the graphite.

[0066] S5. Preparation of the first composite slurry: Add the conductive adhesive liquid from step S3 to the stirring tank that wets the graphite in step S4, adjust the solid content of the composite slurry to 68%, and make it into a mud-like state; first, stir at a revolution speed of 15 rpm for 10 minutes and then scrape the material, then stir at a revolution speed of 20 rpm and a dispersion speed of 600 rpm for 90 minutes, and turn on the cooling water circulation system during the stirring process.

[0067] S6. Preparation of the second composite slurry: Add the first adhesive solution prepared in step S2 to the slurry in step S6, and add an appropriate amount of deionized water for uniform dispersion. First, stir at a revolution speed of 15 rpm and a dispersion speed of 800 rpm for 10 minutes and then scrape the material; then stir at a revolution speed of 30 rpm and a dispersion speed of 3200 rpm for 60 minutes. During the dispersion process, a vacuum is drawn with a vacuum degree of -88 kPa to -92 kPa to obtain the second composite slurry.

[0068] S7. Preparation of the third composite slurry: Adjust the viscosity of the second composite slurry in step S6, add a certain amount of deionized water, stir for 30 min at a revolution speed of 30 rpm and a dispersion speed of 3200 rpm, and apply vacuum during the dispersion process to a vacuum degree of -88 kPa to -92 kPa to obtain the third composite slurry.

[0069] S8. Preparation of lithium battery negative electrode slurry: Add styrene-butadiene rubber (SBR) solution to the third composite slurry, rotate at 20 rpm, disperse at 500 rpm, stir for 30 min, vacuum during dispersion, vacuum degree -88 kPa to -92 kPa, and finally reverse vacuum defoaming to obtain lithium-ion battery negative electrode slurry.

[0070] The lithium battery slurry prepared above was uniformly coated on the negative electrode current collector, and after drying and rolling, lithium titanate negative electrode sheet was obtained. Its electrical properties such as resistivity and internal resistance were tested.

[0071] The physical properties of the negative electrode slurry obtained in Examples 1 and 2 and the electrical properties of the corresponding negative electrode sheets are detailed in Tables 1 and 2.

[0072] Table 1 Physical properties of lithium battery anode slurry

[0073]

[0074] Table 2 Electrical properties of the negative electrode

[0075]

[0076] As shown in Tables 1 and 2, the slurry obtained by the homogenization process of the present invention in Examples 1 and 2 has better dispersibility of negative electrode slurry, the solid content of the upper and lower layers is basically stable, and sedimentation is not easy to occur. Even for novel conductive agents that are not easy to disperse, the dispersion effect is better. The initial viscosity of the negative electrode slurry is slightly lower, which is suitable for electrode coating and has a good leveling effect. The viscosity increases after 24 hours of storage, but the change is still within a suitable range. The resulting negative electrode sheet has lower resistivity, higher cell capacity, and higher initial efficiency, and the overall performance of the cell is better.

[0077] In Example 1, the composite conductive agent used was only 0.5%, while in Example 2, the conductive agent SP was 1%. The composite conductive agent achieved better overall cell performance with half the amount, and had a higher liquid retention coefficient, lower resistivity, and lower charging DCR. This indicates that the conductive network construction in Example 1 was better, resulting in better cycle performance. For battery design, this means that the proportion of auxiliary materials can be reduced within the limited casing space, leaving more space to increase the content of the 0.5% negative electrode active material graphite, further improving the energy density of the battery. Therefore, Example 1 has significant advantages over Example 2.

[0078] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A homogenization process for lithium battery anode slurry, characterized in that: Includes the following steps: S1. Preparation of composite conductive slurry: After mixing the conductive agent, dispersant and deionized water, disperse them in a stirrer to obtain a composite conductive slurry for later use; S2. Preparation of thickening solution: Sodium carboxymethyl cellulose is added to deionized water and stirred and dispersed in a planetary mixer to prepare a thickening solution with a solid content of 1-2%. S3. Preparation of the first adhesive solution: Add PAA or its copolymer water-based binder with a solid content of 40% to the thickening liquid, further disperse to obtain the first adhesive solution, and take out 40-50% of the first adhesive solution for later use. S4. Preparation of conductive adhesive solution: Add the composite conductive slurry from step S1 to the remaining first adhesive solution and disperse it again to obtain a conductive adhesive solution for later use. S5. Graphite wetting: Add deionized water to the graphite for wetting and stir to disperse; the amount of deionized water is 20-30% of the graphite mass; S6. Preparation of the first composite slurry: Add the conductive adhesive solution from step S4 to the stirring tank that wets the graphite in step S5, adjust the solid content of the composite slurry to 65-70%, and stir to disperse. S7. Preparation of the second composite slurry: Add the first adhesive liquid prepared in step S3 to the slurry in step S6, and add deionized water to disperse it evenly. Vacuum is drawn during the dispersion process to obtain the second composite slurry. S8. Preparation of the third composite slurry: Adjust the viscosity of the second composite slurry in step S7, add deionized water, stir and disperse, and vacuum during the dispersion process to obtain the third composite slurry. S9. Preparation of lithium battery negative electrode slurry: Add styrene-butadiene rubber solution to the third composite slurry, stir and disperse, vacuum during dispersion, and finally reverse vacuum defoaming to obtain lithium-ion battery negative electrode slurry; The negative electrode slurry for lithium-ion batteries includes graphite, conductive agent, binder, thickener, and solvent. The conductive agent includes carbon nanotubes, conductive carbon black, and graphene; the thickener includes sodium carboxymethyl cellulose; the binder includes waterborne binders such as PAA or its copolymers and styrene-butadiene rubber; the solvent is deionized water; the total solid content in the negative electrode slurry is 46-50%, and the initial viscosity is 2500-4000 mPa·s.

2. The lithium battery anode slurry homogenization process according to claim 1, characterized in that: Aqueous binders of PAA or its copolymers include at least one of LA136D and LB300.

3. The lithium battery anode slurry homogenization process according to claim 1, characterized in that: The solutes in the negative electrode slurry, by mass percentage, are: graphite 95-97%, conductive agent 0.5%-1.5%, binder 1.4-2.3%, and thickener 0.8-1.6%.

4. The lithium battery anode slurry homogenization process according to claim 3, characterized in that: The conductive agent contains, by mass percentage, 40-60% conductive carbon black, 30-50% carbon nanotubes, and 10-20% graphene.

5. The lithium battery anode slurry homogenization process according to claim 1, characterized in that: Styrene-butadiene rubber accounts for 1% to 2%.

6. The lithium battery anode slurry homogenization process according to claim 1, characterized in that, In step S5, the graphite is first rotated at 15-20 rpm in a planetary mixer and stirred for 10 minutes, then scraped off. After that, the mixture is rotated at 15-25 rpm, dispersed at 200-300 rpm, and stirred for 30-40 minutes.

7. The lithium battery anode slurry homogenization process according to claim 1, characterized in that: In step S6, the composite slurry is first stirred at a revolution speed of 15-20 rpm for 10 minutes and then scraped. After that, it is stirred at a revolution speed of 15-25 rpm and a dispersion speed of 500-600 rpm for 70-90 minutes. During the stirring process, the cooling water circulation system is turned on.

8. The lithium battery anode slurry homogenization process according to claim 1, characterized in that: In step S6, the composite slurry is first stirred at a revolution speed of 15-20 rpm for 10 minutes and then scraped. After that, it is stirred at a revolution speed of 15-25 rpm and a dispersion speed of 500-600 rpm for 70-90 minutes. During the stirring process, the cooling water circulation system is turned on.

9. The lithium battery anode slurry homogenization process according to claim 1, characterized in that, In step S7, the composite slurry is first stirred at a revolution speed of 15-20 rpm and a dispersion speed of 800-1000 rpm for 10 minutes and then scraped off; then it is stirred at a revolution speed of 25-35 rpm and a dispersion speed of 2500-3500 rpm for 60-90 minutes, with a vacuum degree of -88 kPa to -92 kPa during the dispersion process, to obtain the second composite slurry.

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