Aqueous compounded slurry and preparation method thereof, and lithium ion battery negative electrode material

Abstract

The present application belongs to the technical field of lithium battery negative electrode slurry, and particularly relates to a water-based compound slurry, a preparation method thereof and a lithium ion battery negative electrode material, comprising the following steps: S1, dissolving amino alcohol and CMC in deionized water to obtain a dispersion glue solution; S2, adding SWCNT and MWCNT into independent dispersion glue solutions respectively for wetting, and pre-dispersing using a high-pressure homogenizer to obtain SWCNT pre-dispersion liquid and MWCNT pre-dispersion liquid; S3, dispersing the SWCNT pre-dispersion liquid and the MWCNT pre-dispersion liquid through a high-pressure jet homogenizer to obtain SWCNT slurry and MWCNT slurry; and S4, mixing the SWCNT slurry and the MWCNT slurry to obtain a water-based compound slurry; the present application preliminarily disperses the agglomerated structure of carbon nanotubes by using the shearing force and the cavitation effect of the high-pressure homogenizer, and then performs secondary dispersion using the high-pressure jet homogenizer, so that the SWCNT and the MWCNT are further dispersed into fibrous conductive carbon tubes with high aspect ratio and poor agglomeration; the MWCNT with high aspect ratio can have better conductive performance and cycle performance than traditional MWCNT.

Description

Technical Field

[0001] This invention belongs to the field of lithium battery anode slurry technology, specifically relating to an aqueous compound slurry and its preparation method, and lithium-ion battery anode materials. Background Technology

[0002] In the early stages of lithium-ion battery manufacturing, pulp preparation is one of the most important processes. Pulp preparation refers to the process of uniformly dispersing the positive and negative electrode materials, conductive agents, binders, and other materials of lithium-ion batteries in water or a certain organic solvent (mainly NMP) using methods such as stirring, centrifugation, and ball milling.

[0003] SWCNTs (single-walled carbon nanotubes) are commonly used conductive agents in existing silicon anode batteries. They have excellent performance but are expensive. Traditional MWCNTs (multi-walled carbon nanotubes) are small, aggregated particles with generally poor long-range conductivity. Although they are easy to obtain, they are not suitable for silicon anode slurries in lithium-ion batteries.

[0004] Therefore, how to improve the long-range conductivity of MWCNT in negative electrode slurry is a technical problem that urgently needs to be solved in this field.

[0005] It should be noted that the information disclosed in this background section is only for understanding the background technology of the present application concept, and therefore, the above description is not considered to constitute prior art information. Summary of the Invention

[0006] This disclosure provides at least one aqueous compound slurry and its preparation method, as well as a lithium-ion battery anode material.

[0007] In a first aspect, embodiments of this disclosure provide a method for preparing an aqueous compound slurry, comprising the following steps: S1, dissolving amino alcohol and CMC in deionized water to obtain a dispersion solution; S2, adding SWCNT and MWCNT to separate dispersion solutions for wetting, and pre-dispersing them using a high-pressure homogenizer to obtain SWCNT pre-dispersion liquid and MWCNT pre-dispersion liquid; S3, dispersing the SWCNT pre-dispersion liquid and MWCNT pre-dispersion liquid using a high-pressure jet homogenizer to obtain SWCNT slurry and MWCNT slurry; S4, mixing the SWCNT slurry and MWCNT slurry to obtain an aqueous compound slurry.

[0008] In one optional embodiment, the sum of the mass fractions of amino alcohol and CMC in the dispersion solution of step S1 is 0.4%-0.8%.

[0009] In one optional implementation, the high-pressure homogenizer pre-dispersion in step S2 specifically includes:

[0010] At a temperature of 24±4℃, with the required input energy for the pre-dispersed slurry set at 0.3 kWh / kg, calculate the homogenization duration T; T satisfies the following relationship: In the formula, T is the required homogenization time in hours; E is the input energy in kilowatt-hours per kilogram; M total Total output is expressed in kilograms; P represents the power of the high-pressure homogenizer, expressed in kilowatts.

[0011] In one optional implementation, the pretreated MWCNTs have a particle size of no more than 20 μm.

[0012] In one optional implementation, the mass fraction of SWCNT and the mass fraction of MWCNT in step S2 are 0.4%-0.8%.

[0013] In one optional embodiment, the high-pressure jet homogenizer dispersion in step S3 specifically includes: dispersing the SWCNT pre-dispersion liquid and the MWCNT pre-dispersion liquid using a high-pressure jet homogenizer, so that some of the SWCNTs and all of the MWCNTs form fibrous conductive carbon nanotubes; wherein the dispersion pressure of the SWCNTs is 200-1000 bar, and the number of homogenization cycles is 10-20; the dispersion pressure of the MWCNTs is 200-500 bar, and the number of homogenization cycles is 10-20.

[0014] In one optional embodiment, the outer diameter OD value of the fibrous conductive carbon tube is not less than 0.45abs.

[0015] In one alternative embodiment, the nozzle orifice diameter used in the high-pressure jet homogenizer is no greater than φ0.5mm.

[0016] Secondly, this disclosure also provides an aqueous compound slurry, obtained by the method described above, comprising the following components by mass fraction: 0.4%-0.8% SWCNT and 0.4%-0.8% fibrous conductive carbon nanotubes; wherein the outer diameter OD value of the fibrous conductive carbon nanotubes is not less than 0.45abs.

[0017] Thirdly, this disclosure also provides a lithium-ion battery anode material, which is obtained by coating a current collector with the aqueous compound slurry as described above.

[0018] The beneficial effects of this invention are that the aqueous compound slurry and its preparation method, as well as the lithium-ion battery anode material, initially disperse the agglomerated structure of carbon nanotubes using a high-pressure homogenizer with shear force and cavitation effect. Subsequently, a high-pressure jet homogenizer is used for secondary dispersion, further dispersing SWCNTs and MWCNTs into fibrous conductive carbon nanotubes with high aspect ratio and low agglomeration. When these fibrous conductive carbon nanotubes are applied to the slurry, the agglomeration effect caused by traditional MWCNTs can be avoided, achieving a significant improvement in long-range conductivity. At the same time, in silicon-based anodes, MWCNTs with high aspect ratio can also achieve better conductivity and cycle performance than traditional MWCNTs.

[0019] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 A 100x magnified view of an SWCNT slurry provided in an embodiment of this disclosure. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0024] As used herein, the phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” etc., generally refer to the fact that a particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of this disclosure. Therefore, a particular feature, structure, or characteristic can be included in more than one embodiment of this disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms “example,” “exemplary,” etc., are used to “serve as an example, instance, or illustration.” Any implementation, aspect, or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. Rather, the use of the terms “example,” “exemplary,” etc., is intended to present concepts in a specific manner.

[0025] In this document, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as “at least one of…” modify the entire list of elements when following a list of elements, rather than individual elements in the list. For example, the expression “at least one of a, b, and c” should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0026] The terminology used herein is for the purpose of describing specific exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may also be intended to include plural forms unless otherwise clearly stated herein. The terms “comprising,” “including,” and “having” are inclusive and thus specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein should not be construed as requiring them to be performed in the specific order discussed or shown, unless specifically identified as such. Additional or alternative steps may be employed.

[0027] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0028] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0029] This disclosure provides a method for preparing an aqueous compound slurry, comprising the following steps: S1, dissolving amino alcohol and CMC (sodium carboxymethyl cellulose) in deionized water to obtain a dispersion solution; S2, adding SWCNT and MWCNT to separate dispersion solutions for wetting, and pre-dispersing them using a high-pressure homogenizer to obtain SWCNT pre-dispersion and MWCNT pre-dispersion; S3, dispersing the SWCNT pre-dispersion and MWCNT pre-dispersion using a high-pressure jet homogenizer to obtain SWCNT slurry and MWCNT slurry; S4, mixing the SWCNT slurry and MWCNT slurry to obtain an aqueous compound slurry.

[0030] In one optional embodiment, the sum of the mass fractions of amino alcohol and CMC in the dispersion solution of step S1 is 0.4%-0.8%.

[0031] In an optional implementation, the pre-dispersion of the high-pressure homogenizer in step S2 specifically includes: calculating the homogenization duration T at a temperature of 24±4℃, with the required input energy for the pre-dispersed slurry set at 0.3 kWh / kg; wherein T satisfies the following relationship: In the formula, T is the required homogenization time in hours; E is the input energy in kilowatt-hours per kilogram; M total Total output is expressed in kilograms; P represents the power of the high-pressure homogenizer, expressed in kilowatts.

[0032] Specifically, for example, for 10 kg of dispersed material, under the condition of using a homogenizer with a power of 4 kW, the formula as described above is used: T = (kWh / kg * 10 kg) / 4 kWh = 0.75 hours.

[0033] Specifically, pre-dispersion aims to deagglomerate CNT powder. Currently, SWCNTs produced by this process are highly entangled flocculents. Pre-dispersion allows them to absorb some energy, reducing their entanglement and enabling them to be dispersed through the nozzle, preventing nozzle clogging during high-pressure jet homogenization. However, excessive dispersion can lead to a decrease in long-range conductivity. Therefore, calculating the homogenization duration can balance dispersion effectiveness and long-range conductivity. Similarly, although SWCNTs are less entangled than MWCNTs, they can still achieve better pre-dispersion through a high-pressure homogenizer, thereby improving the efficiency of high-pressure jet homogenization.

[0034] In one optional implementation, the pretreated MWCNTs have a particle size of no more than 20 μm.

[0035] In one optional implementation, the mass fraction of SWCNT and the mass fraction of MWCNT in step S2 are 0.4%-0.8%.

[0036] In an optional embodiment, the high-pressure jet homogenizer dispersion in step S3 specifically includes: dispersing the SWCNT pre-dispersion liquid and the MWCNT pre-dispersion liquid using a high-pressure jet homogenizer, so that a portion (not less than 10%) of the SWCNTs and all of the MWCNTs form fibrous conductive carbon nanotubes; wherein the dispersion pressure of the SWCNTs is 200-1000 bar, and the homogenization times are 10-20 times; the dispersion pressure of the MWCNTs is 200-500 bar, and the homogenization times are 10-20 times.

[0037] Specifically, carbon nanotubes are dispersed through the cavitation, impact, and shearing effects of a high-pressure jet homogenizer, especially for MWCNTs. Since the carbon nanotube strength of MWCNTs is lower than that of SWCNTs, a nozzle with a smaller aperture is needed for homogenization to allow for more cavitation impact effects, thereby dispersing them into fibrous carbon nanotubes. A smaller homogenization pressure is used to reduce the shearing effect, thus producing MWCNTs with a high aspect ratio, avoiding the breakage of weaker MWCNTs and the formation of secondary agglomeration.

[0038] In one optional embodiment, the outer diameter OD value of the fibrous conductive carbon tube is not less than 0.45abs.

[0039] Specifically, the slurry is diluted and subjected to optical density testing. The optical density value is calculated by multiplying the powder mass fraction in the slurry by 100,000. For example, a 0.4% SWCNT slurry is diluted by 0.4% * 100,000 and then tested for optical density. The higher the optical density value, the higher the degree of dispersion.

[0040] In one alternative embodiment, the nozzle orifice diameter used in the high-pressure jet homogenizer is no greater than φ0.5mm.

[0041] Specifically, because there are agglomerated powders in the pre-dispersed slurry, smaller nozzles are not conducive to the dispersion of agglomerated powders and may cause blockage. Larger nozzles will reduce the effects of cavitation and impact, and the dispersion mode will be more of the shear effect between valve bodies, causing MWCNTs to break and re-agglomerate.

[0042] Secondly, this disclosure also provides an aqueous compound slurry, obtained by the method described above, comprising the following components by mass fraction: 0.4%-0.8% SWCNT and 0.4%-0.8% fibrous conductive carbon nanotubes; wherein the OD value of the fibrous conductive carbon nanotubes is not less than 0.45abs (optical density value).

[0043] Thirdly, this disclosure also provides a lithium-ion battery anode material, which is obtained by coating a current collector with the aqueous compound slurry as described above.

[0044] Example 1:

[0045] Preparation of water-based compound slurry:

[0046] S1, Dissolve 10g amino alcohol and 40g CMC in 4950g deionized water to obtain a dispersion solution;

[0047] S2, SWCNT and MWCNT were added to separate dispersion solutions for wetting and pre-dispersed using a high-pressure homogenizer. SWCNT was homogenized at 24°C for 0.375 h and MWCNT was homogenized at 24°C for 0.375 h to obtain SWCNT pre-dispersion and MWCNT pre-dispersion.

[0048] S3, the SWCNT predispersant and MWCNT predispersant are dispersed using a high-pressure jet homogenizer. The dispersion pressure of the SWCNT predispersant is 700 bar, and the homogenization is performed 10 times. The dispersion pressure of the MWCNT predispersant is 300 bar, and the homogenization is performed 10 times, resulting in an SWCNT slurry and... Figure 1 The MWCNT slurry shown;

[0049] like Figure 1 As shown, SWCNTs dispersed by high-pressure jet exhibit a fibrous structure with a significantly improved aspect ratio.

[0050] S4. Mix SWCNT slurry and MWCNT slurry to obtain water-based compound slurry, hereinafter referred to as compound CNT.

[0051] The negative electrode slurry was prepared according to the solid mass ratio of graphite, silicon anode, CMC, carbon black, PAA, SBR, and compound CNT in 81.2:14.3:1:0.6:1.6:1.2:0.1, wherein the compound CNT consisted of 1 part SWCNT and 40 parts MWCNT.

[0052] First, CMC and deionized water are added to prepare the adhesive with a solid content of 2%. The subsequent additions are carbon black, graphite, silicon anode, CNT, PAA, and SBR. Finally, deionized water is added to adjust the solid content to 50%.

[0053] Before adding the SBR, the orbital speed was 3500 RPM and the rotational speed was 50 RPM. After adding the SBR, the orbital speed was 500 RPM and the rotational speed was 10 RPM. After homogenization for 120 minutes, the mixture was coated onto the current collector and dried at 80℃. Then, the electrode sheet was cut to serve as the negative electrode, and NCM was used as the positive electrode to prepare a pouch battery. The battery was then tested using the Xinwei testing system. The charge / discharge conditions were set to 200 cycles at 1C. As shown in Table 1, the results show that the first-cycle discharge capacity was 1864 mAh and the first-cycle efficiency was 76.3%.

[0054] Comparative Example 1:

[0055] The anode slurry was prepared according to the solid mass ratio of graphite, silicon anode, CMC, carbon black, PAA, SBR, and SWCNT of 81.2:14.3:1:0.6:1.6:1.2:0.05.

[0056] First, CMC and deionized water are added to prepare the adhesive with a solid content of 2%. The subsequent additions are carbon black, graphite, silicon anode, CNT, PAA, and SBR. Finally, deionized water is added to adjust the solid content to 50%.

[0057] Before adding SBR, the orbital speed was 3500 RPM and the rotational speed was 50 RPM. After adding SBR, the orbital speed was 500 RPM and the rotational speed was 10 RPM. After homogenization for 120 minutes, the mixture was coated onto the current collector and dried at 80℃. Then, the electrode sheet was cut to serve as the negative electrode, and NCM was used as the positive electrode to prepare a pouch battery. The battery was tested using the Xinwei testing system. The charge and discharge conditions were set to 200 cycles at 1C. As shown in Table 1, the results show that the first-cycle discharge capacity was 1807 mAh, and the first-cycle efficiency was 75.7%.

[0058] Example 2:

[0059] Preparation of water-based compound slurry:

[0060] S1, Dissolve 10g amino alcohol and 40g CMC in 4950g deionized water to obtain a dispersion solution;

[0061] S2, SWCNT and MWCNT were added to separate dispersion solutions for wetting and pre-dispersed using a high-pressure homogenizer. SWCNT was homogenized at 24°C for 0.375 h and MWCNT was homogenized at 24°C for 0.375 h to obtain SWCNT pre-dispersion and MWCNT pre-dispersion.

[0062] S3, the SWCNT predispersant and MWCNT predispersant are dispersed by a high-pressure jet homogenizer, wherein the dispersion pressure of the SWCNT predispersant is 700 bar and the homogenization is performed 10 times, and the dispersion pressure of the MWCNT predispersant is 300 bar and the homogenization is performed 10 times, to obtain SWCNT slurry and MWCNT slurry.

[0063] The negative electrode slurry was prepared according to the solid mass ratio of graphite, silicon anode, CMC, carbon black, PAA, SBR, and compound CNT in 81.2:14.3:1:0.6:1.6:1.2:0.2, wherein the compound CNT consisted of 1 part SWCNT and 40 parts MWCNT.

[0064] First, CMC and deionized water are added to prepare the adhesive with a solid content of 2%. The subsequent additions are carbon black, graphite, silicon anode, CNT, PAA, and SBR. Finally, deionized water is added to adjust the solid content to 50%.

[0065] Before adding SBR, the orbital speed was 3500 RPM and the rotational speed was 50 RPM. After adding SBR, the orbital speed was 500 RPM and the rotational speed was 10 RPM. After homogenization for 120 minutes, the mixture was coated onto the current collector and dried at 80℃. Then, the electrode sheet was cut to serve as the negative electrode, and NCM was used as the positive electrode to prepare a pouch battery. The battery was tested using the Xinwei testing system. The charge and discharge conditions were set to 200 cycles at 1C. As shown in Table 1, the results show that the first-cycle discharge capacity was 1845 mAh, and the first-cycle efficiency was 75.9%.

[0066] Comparative Example 2

[0067] Preparation of water-based compound slurry:

[0068] S1, Dissolve 10g amino alcohol and 40g CMC in deionized water to obtain a dispersion solution;

[0069] S2, SWCNT is added to the dispersion solution to wet it, and pre-dispersed using a high-pressure homogenizer. SWCNT is homogenized at 24℃ for 0.375h to obtain SWCNT pre-dispersion solution.

[0070] S3, the SWCNT pre-dispersion liquid is dispersed by a high-pressure jet homogenizer. The dispersion pressure of the SWCNT pre-dispersion liquid is 700 bar, and the homogenization is performed 10 times to obtain SWCNT slurry.

[0071] S4, 1 part of SWCNT slurry is compounded with 40 parts of ordinary low aspect ratio MWCNT slurry that has been sand-milled and dispersed to obtain compound CNT slurry;

[0072] The negative electrode slurry was prepared according to the solid mass ratio of graphite, silicon anode, CMC, carbon black, PAA, SBR, and compound CNT in 81.2:14.3:1:0.6:1.6:1.2:0.1, wherein the compound CNT consisted of 1 part SWCNT and 40 parts MWCNT.

[0073] First, CMC and deionized water are added to prepare the adhesive with a solid content of 2%. The subsequent additions are carbon black, graphite, silicon anode, CNT, PAA, and SBR. Finally, deionized water is added to adjust the solid content to 50%.

[0074] Before adding SBR, the orbital speed was 3500 RPM and the rotational speed was 50 RPM. After adding SBR, the orbital speed was 500 RPM and the rotational speed was 10 RPM. After homogenization for 120 minutes, the mixture was coated onto the current collector and dried at 80℃. Then, the electrode sheet was cut to serve as the negative electrode, and NCM was used as the positive electrode to prepare a pouch battery. The battery was tested using the Xinwei testing system. The charge and discharge conditions were set to 200 cycles at 1C. As shown in Table 1, the results show that the first-cycle discharge capacity was 1801 mAh, and the first-cycle efficiency was 73.6%.

[0075] Specifically, based on the total mass fraction in the pouch battery, the performance of the pouch batteries obtained in Examples 1-2 and Comparative Examples 1-2 was tested, and the results are shown in Table 1 below.

[0076] Table 1

[0077] Example 1: 0.1% compound 4112 15.4 1864 76.3 89.5 Comparative Example 1: 0.05% SWCNT 4019 16.1 1807 75.7 89.7 Example 2: 0.2% compound 4284 15.5 1845 75.9 90.2 Comparative Example 2: 0.1% Common Compound 4112 17.1 1801 73.6 83.8

[0078] As shown in Table 1, the fibrous MWCNT slurry prepared by the method provided in this application, when combined with SWCNT slurry to form a compound slurry, exhibits better first-cycle discharge capacity, first-cycle efficiency, and cycle efficiency when applied in a silicon anode battery system. It can effectively reduce or replace the use of SWCNT in the silicon anode system, and its performance is superior to that of traditional multi-walled dispersion slurries.

[0079] Specifically, in Comparative Example 2, SWCNTs were only dispersed using a conventional process, and the aspect ratio did not meet the specified requirements. Therefore, they could not achieve the performance achievable in Example 1 at the same concentration. This is because the volume change of silicon anode materials during charge and discharge can reach up to 300%-400%, which can easily lead to material structure damage and electrode pulverization, affecting cycle life. At the same time, silicon has low conductivity, which affects electron transport and lithium-ion diffusion. Therefore, fibrous MWCNTs with a high aspect ratio can form a stable three-dimensional network structure in silicon anode materials, improving conductivity and alleviating volume expansion, thereby improving cycle performance. In other words, compared with Comparative Example 2, fibrous MWCNTs with a high aspect ratio have higher efficiency after 200 cycles at 1C.

[0080] Furthermore, the cost of 0.05% concentration of SWCNT in Comparative Example 1 is much higher than that of 0.1% compound in Example 1, but under the synergistic effect of fibrous MWCNT slurry and SWCNT slurry, the long-range conductivity of Example 1 does not decrease but increases.

[0081] In summary, this aqueous compound slurry and its preparation method, as well as the lithium-ion battery anode material, utilize a high-pressure homogenizer to initially disperse the aggregated structure of carbon nanotubes through shear force and cavitation effect. Subsequently, a high-pressure jet homogenizer is used for secondary dispersion, further dispersing SWCNTs and MWCNTs into high aspect ratio, non-agglomerated fibrous conductive carbon nanotubes. The application of these fibrous conductive carbon nanotubes in the slurry can avoid the agglomeration effect caused by traditional MWCNTs, achieving a significant improvement in long-range conductivity. At the same time, in silicon-based anodes, the high aspect ratio MWCNTs can also achieve better conductivity and cycle performance than traditional MWCNTs.

[0082] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for preparing an aqueous compound slurry, characterized in that, Includes the following steps: Step S1: Dissolve amino alcohol and CMC in deionized water to obtain a dispersion solution; Step S2: Wet SWCNT and MWCNT separately into independent dispersion solutions and pre-disperse them using a high-pressure homogenizer to obtain SWCNT pre-dispersion and MWCNT pre-dispersion. Step S3: Disperse the SWCNT predispersant and MWCNT predispersant using a high-pressure jet homogenizer to obtain SWCNT slurry and MWCNT slurry. as well as, Step S4: Mix SWCNT slurry and MWCNT slurry to obtain water-based compound slurry; The total mass fraction of amino alcohol and CMC in the dispersion solution of step S1 is 0.4%-0.8%; The pre-dispersion of the high-pressure homogenizer in step S2 specifically includes: At a temperature of 24±4℃, with the required input energy for the pre-dispersed slurry set at 0.3 kWh / kg, calculate the duration T of homogenization. The T satisfies the following relationship: ; In the formula, T is the required homogenization time, in hours; E represents the energy input, measured in kilowatt-hours per kilogram. M total Total output, in kilograms; P represents the power of the high-pressure homogenizer, measured in kilowatts.

2. The preparation method according to claim 1, characterized in that, The particle size of pre-dispersed MWCNTs is no greater than 20 μm.

3. The preparation method according to claim 1, characterized in that, In step S2, the mass fraction of SWCNT is 0.4%-0.8%, and the mass fraction of MWCNT is 0.4%-0.8%.

4. The preparation method according to claim 1, characterized in that, The high-pressure jet homogenizer dispersion in step S3 specifically includes: The SWCNT predispersant and MWCNT predispersant are dispersed using a high-pressure jet homogenizer to form fibrous conductive carbon nanotubes. The dispersion pressure of the SWCNT is 200-1000 bar, and the number of homogenization cycles is 10-20. The dispersion pressure of the MWCNT is 200-500 bar, and the homogenization times are 10-20.

5. The preparation method according to claim 4, characterized in that, The OD value of the fibrous conductive carbon nanotube is not less than 0.45abs.

6. The preparation method according to claim 4, characterized in that, The nozzle orifice diameter used in the high-pressure jet homogenizer is φ0.3-0.5mm.

7. A water-based compound slurry, characterized in that, Obtained by the method described in claim 4, comprising the following components by mass fraction: SWCNT 0.4%-0.8%, MWCNT 0.4%-0.8%; among which, The OD value of the fibrous conductive carbon nanotube is not less than 0.45 abs.

8. A lithium-ion battery anode material, characterized in that, The mixture is obtained by coating the current collector with the water-based compound slurry as described in claim 7.

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