Structure-energy storage integrated multi-dimensional conductive network composition, negative electrode material and preparation method

Abstract

The invention belongs to the technical field of conductive materials, and provides a structure-energy storage integrated multi-dimensional conductive network composition, a negative electrode material and a preparation method. The method comprises the following steps: mixing conductive carbon black, graphene, carbon nanotubes, conductive ceramic particles and water to obtain a multi-dimensional conductive network composition; the mass ratio of the conductive carbon black to the carbon nanotubes is (0.8-1.2): (0.8-1.2), the mass of the graphene is 0.1-2% of the sum of the mass of the conductive carbon black and the carbon nanotubes, and the mass of the conductive ceramic particles is 0.5-5% of the sum of the mass of the conductive carbon black and the carbon nanotubes. Different conductive components are strictly proportioned and are subjected to dispersion process control, so that mutually communicated conductive frameworks are formed in the high-specific-capacity negative electrode active material, a multi-level conductive path is constructed microcosmically, and formation and stable existence of a multi-dimensional conductive network are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of conductive materials, and particularly relates to a multi-dimensional conductive network composition integrated with structure and energy storage, a negative electrode material, and a preparation method thereof. Background Art

[0002] Common conductive agents in the negative electrode of lithium-ion batteries include conductive carbon black (such as KetjenBlack, acetylene black), carbon nanotubes (CNT), graphene, and conductive polymers or ceramic materials. These conductive agents can effectively reduce electrode polarization and improve the utilization rate of specific capacity and rate performance. However, when multiple conductive agents act synergistically in a high specific capacity Si-C negative electrode system, the following problems are faced: (1) The dispersion stability of each conductive agent in aqueous slurry or organic slurry is poor, and it is easy to agglomerate, resulting in uneven local conductivity; (2) Carbon nanotubes and graphene are prone to form local stacking in the electrode, affecting the continuity of the conductive framework and the control of pore structure; (3) Introducing conductive ceramics (such as TiC) helps to improve the structural stability and high rate performance, but how to form a complementary structure with carbon materials needs to be optimized.

[0003] For the application of structure-energy storage integrated carbon fiber composites, it is particularly important to construct a uniformly distributed and continuously conductive three-dimensional network in the negative electrode layer. This will enable the negative electrode to maintain a stable electron path under repeated charge and discharge and mechanical stress, achieving high power density and long life.

[0004] Therefore, it is of great significance to research and obtain a conductive agent composition integrated with structure and energy storage that forms a stable multi-dimensional conductive network and a multi-dimensional conductive network negative electrode material. Summary of the Invention

[0005] The purpose of the present invention is to provide a multi-dimensional conductive network composition integrated with structure and energy storage, a negative electrode material, and a preparation method thereof in order to overcome the deficiencies of the prior art.

[0006] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0007] The present invention provides a preparation method of a multi-dimensional conductive network composition integrated with structure and energy storage, comprising the following steps:

[0008] Mix conductive carbon black, graphene, carbon nanotubes, and conductive ceramic particles to obtain a multi-dimensional conductive network composition;

[0009] The mass ratio of conductive carbon black to carbon nanotubes is 0.8 - 1.2:0.8 - 1.2, the mass of graphene is 0.1 - 2% of the sum of the masses of conductive carbon black and carbon nanotubes, and the mass of conductive ceramic particles is 0.5 - 5% of the sum of the masses of conductive carbon black and carbon nanotubes.

[0010] Preferably, the conductive carbon black is Ketjen Black, and the conductive ceramic particles are TiC.

[0011] Preferably, the mixing method includes one or more of ultrasonic dispersion, shear mixing, and planetary ball milling; the ultrasonic dispersion time is 10 - 60 min, the shear mixing speed is 3000 - 8000 rpm, and the planetary ball milling time is 0.5 - 2 h.

[0012] Preferably, the mixing is a first mixing of conductive carbon black and graphene, a second mixing of the first mixture and carbon nanotubes, and a third mixing of the second mixture and conductive ceramic particles.

[0013] Preferably, conductive ceramic particles, a dispersant, and water are mixed to obtain a slurry. After adjusting the pH value of the slurry, it is then mixed with the second mixture; the pH value of the slurry is adjusted to 8 - 11.

[0014] The present invention also provides a structure - energy storage integrated multi - dimensional conductive network composition prepared by the described preparation method.

[0015] The present invention also provides a method for preparing a multi - dimensional conductive network anode material from the described structure - energy storage integrated multi - dimensional conductive network composition. The multi - dimensional conductive network composition, anode active material, and aqueous binder system are mixed, and the mixed slurry is coated on a carbon fiber substrate to obtain a multi - dimensional conductive network anode material;

[0016] The sum of the masses of conductive carbon black, graphene, carbon nanotubes, and conductive ceramic particles is 2 - 10% of the mass of the anode active material.

[0017] Preferably, the carbon fiber substrate is a surface - modified carbon fiber substrate; the anode active material is Si - C, SiOx, or a metal alloy.

[0018] The present invention also provides a multi - dimensional conductive network anode material prepared by the described method.

[0019] The beneficial effects of the present invention include the following points:

[0020] 1) The present invention strictly controls the proportioning and dispersion process of different conductive components such as Ketjen Black, CNT, graphene, and TiC, enabling them to form an interconnected conductive framework in high - specific - capacity anode active materials such as Si - C, SiO x or Sn - based alloys, constructing a multi - level conductive path microscopically to ensure the formation and stable existence of a multi - dimensional conductive network.

[0021] 2) The multi-dimensional conductive network composition of the present invention forms a stable, continuous, and efficient multi-dimensional conductive framework in the negative electrode layer, thereby significantly improving the charge transport ability and cycling performance of the electrode; in the multi-dimensional conductive network composition, KB provides a basic conductive framework, CNT forms a one-dimensional conductive bridge, graphene constructs a two-dimensional extended interface, and TiC enhances rigidity and structural stability at high rates, thus forming a multi-dimensional and multi-scale conductive framework.

[0022] 3) The present invention adopts multi-step processes such as ultrasonic dispersion, planetary ball milling, or shear mixing to uniformly disperse CNT and graphene in the conductive carbon black network and reduce agglomeration; during the process, interface modification is performed on the surface of TiC particles (such as adjusting the pH value of the slurry formulation and adding a dispersant) to enable TiC to be better embedded in the carbon framework and improve the stability of the electrode at high rates.

[0023] 4) The negative electrode material prepared from the multi-dimensional conductive network composition of the present invention exhibits excellent rate performance and long cycling life in half-cell tests; in the application of structure-energy storage integration, the electrode still maintains smooth electronic pathways under mechanical loads and repeated cycling. Detailed implementation manners

[0024] The present invention provides a preparation method for a multi-dimensional conductive network composition for structure-energy storage integration, comprising the following steps:

[0025] Mix conductive carbon black, graphene, carbon nanotubes (CNT), and conductive ceramic particles to obtain a multi-dimensional conductive network composition;

[0026] The mass ratio of conductive carbon black to carbon nanotubes is 0.8 - 1.2:0.8 - 1.2, the mass of graphene is 0.1 - 2% of the sum of the masses of conductive carbon black and carbon nanotubes, and the mass of conductive ceramic particles is 0.5 - 5% of the sum of the masses of conductive carbon black and carbon nanotubes.

[0027] In the present invention, the mass ratio of conductive carbon black to carbon nanotubes is preferably 0.9 - 1.1:0.9 - 1.1, more preferably 1:1; the mass of graphene is preferably 0.5 - 1.5% of the sum of the masses of conductive carbon black and carbon nanotubes, more preferably 0.8 - 1.2%, and most preferably 1%; the mass of conductive ceramic particles is preferably 1 - 4% of the sum of the masses of conductive carbon black and carbon nanotubes, more preferably 1.5 - 3.5%, and most preferably 2 - 3%.

[0028] In the present invention, the conductive carbon black is preferably KetjenBlack (KB), and the conductive ceramic particle is preferably TiC.

[0029] In the present invention, the mixing method preferably includes one or more of ultrasonic dispersion, shear mixing, and planetary ball milling; the time of ultrasonic dispersion is preferably 10 - 60 min, more preferably 20 - 50 min, and still more preferably 30 - 40 min; the rotation speed of shear mixing is preferably 3000 - 8000 rpm, more preferably 4000 - 7000 rpm, and still more preferably 5000 - 6000 rpm, and the time of shear mixing is preferably 8 - 12 min, more preferably 10 min; the grinding time of planetary ball milling is preferably 0.5 - 2 h, more preferably 1 - 1.5 h; the rotation speed of planetary ball milling is preferably 200 - 400 rpm, more preferably 300 rpm.

[0030] In the present invention, ultrasonic dispersion, shear mixing, planetary ball milling, etc. are used to make each conductive component evenly distributed to form a continuous and stable three-dimensional conductive network.

[0031] In the present invention, the mixing is preferably a first mixing of conductive carbon black and graphene, a second mixing of the first mixture and carbon nanotubes, and a third mixing of the second mixture and conductive ceramic particles.

[0032] In the present invention, conductive ceramic particles, a dispersant, and water are mixed to obtain a slurry. After adjusting the pH value of the slurry, it is then mixed with the second mixture; the pH value of the slurry is preferably adjusted to 8 - 11, more preferably adjusted to 9 - 10.

[0033] In the present invention, the purpose of mixing conductive ceramic particles, a dispersant, and water and adjusting the pH value of the slurry is to make TiC better combine with the carbon-based conductive agent; the dispersant is preferably a polycarboxylic acid type dispersant.

[0034] The present invention also provides a structure-energy storage integrated multi-dimensional conductive network composition prepared by the described preparation method.

[0035] The present invention also provides a method for preparing a multi-dimensional conductive network anode material from the described structure-energy storage integrated multi-dimensional conductive network composition. The multi-dimensional conductive network composition, anode active material, and aqueous binder system are mixed, and the mixed slurry is coated on a carbon fiber substrate to obtain a multi-dimensional conductive network anode material;

[0036] The sum of the masses of conductive carbon black, graphene, carbon nanotubes, and conductive ceramic particles is 2 - 10% of the mass of the anode active material.

[0037] In the present invention, the aqueous binder system is preferably a PAA / CMC / SBR (polyacrylic acid / carboxymethyl cellulose sodium / styrene-butadiene rubber) binder system.

[0038] In the present invention, the total mass of the conductive carbon black, graphene, carbon nanotubes, and conductive ceramic particles is preferably 3-8%, more preferably 4-7%, and still more preferably 5-6% of the mass of the negative electrode active material.

[0039] In the present invention, the viscosity of the multi-dimensional conductive network composition is preferably 1000-2000 mPa·s, more preferably 1000-2000 mPa·s, and still more preferably 1500-1600 mPa·s.

[0040] In the present invention, the carbon fiber substrate is preferably a surface-modified carbon fiber substrate; the negative electrode active material is preferably Si-C, SiO x or a metal alloy; the metal alloy is preferably a Sn-based alloy.

[0041] The present invention also provides a multi-dimensional conductive network negative electrode material prepared by the method described above.

[0042] The method of the present invention can obtain a structure-energy storage integrated negative electrode material with excellent rate performance and cycle life; this negative electrode material still maintains good cycle performance and mechanical stability under high energy density and high rate working conditions.

[0043] The technical solutions provided by the present invention will be described in detail below with reference to the examples, but they should not be construed as limiting the protection scope of the present invention.

[0044] In the examples and comparative examples, the particle size of the TiC nanoparticles is 50 nm; the type of the polycarboxylic acid-based dispersant is NOPCALL D-6080; the surface treatment process of the T700 carbon fiber is as follows: the T700 carbon fiber is first treated with 50 W plasma for 60 s to increase the surface energy, and then soaked in a KH550 amino silane ethanol solution (0.5 wt%) for 20 min and dried at 80 °C to improve the hydrophilicity of the fiber surface and the bonding strength with the negative electrode slurry.

[0045] In the small-scale test stage of Examples 1-3, an intermittent ultrasonic disperser is used for ultrasonic dispersion; the volume of the planetary ball mill tank is 0.5-2 L, and the processing capacity is small; the stirring volume of the high-shear disperser is less than 2 L; in the large-scale production of Example 4, it is replaced with a continuous tube-type ultrasonic dispersion device, and the slurry continuously flows through the ultrasonic generating area through a pipeline to reduce the interruption in batch operations; the volume of the planetary ball mill is 5-20 L; a multi-stage shear head or an external circulation type high-shear mixer is used for shear mixing, and the processing capacity can reach dozens to hundreds of liters, and the mixing quality is monitored in real time by means such as an online flow meter and an online viscosity detector.

[0046] Example 1

[0047] 0.02 g of polycarboxylic acid dispersant was used to treat 2 g of TiC nanoparticles, and deionized water was added to make up to 100 g. After stirring and dispersing, the pH value of the slurry was adjusted to 10 to reduce the agglomeration of TiC, and TiC slurry was obtained;

[0048] The mass ratio of Ketjen Black to carbon nanotubes was 1:1, the mass of graphene was 0.5% of the sum of the masses of conductive carbon black and carbon nanotubes, and the mass of TiC nanoparticles was 2% of the sum of the masses of Ketjen Black and carbon nanotubes;

[0049] Ketjen Black and graphene were added to 300 g of deionized water and ultrasonically dispersed at a power of 100 W and a frequency of 40 kHz (intermittent ultrasonic disperser) for 30 min to obtain a mixture; the mixture and carbon nanotubes were shear-mixed at a rate of 5000 rpm for 10 min to form a stable KB-graphene-CNT ternary dispersion system; the TiC slurry was slowly added to the ternary dispersion system and ground in a planetary ball mill at a rate of 300 rpm for 30 min to obtain a highly dispersed multi-dimensional conductive network composition.

[0050] 5 g of the multi-dimensional conductive network composition (dry basis), 100 g of Si-C active material (dry basis), and 5 g of PAA / CMC / SBR binder system (dry basis) were mixed in deionized water. The M of PAA w was 450000, the degree of substitution of CMC was 0.8. In the binder system, the mass ratio of PAA, CMC, and SBR was 1:1:1. After stirring and mixing, the viscosity was adjusted to 1500 mPa·s. The mixture was coated on the surface-treated T700 carbon fiber substrate. By setting the blade gap of the coater to 60 μm, a dry film thickness of 25 μm was achieved. After drying at 70 °C for 1 h, it was further dried at 120 °C for 1.5 h to remove residual moisture and cure the binder, forming a multi-dimensional conductive network negative electrode layer for structure-energy storage integration.

[0051] The dried negative electrode sheet was cut into circular pieces with a diameter of 14 mm. The negative electrode sheet, separator (such as Celgard 2400 or PP / PE composite film), and lithium metal sheet were used as counter electrodes, and a conventional carbonate-based electrolyte (EC / DMC + additive) was used. Assembly was carried out in a glove box (argon atmosphere), and the water content and oxygen content should be strictly controlled below the ppm level. It was pressed and sealed, denoted as the test battery.

[0052] The assembled button cell was charged and discharged 1-2 times at a low current at room temperature (25 °C) to activate the electrode material and stabilize the solid electrolyte interface (SEI film). The cut-off voltage during formation was usually 0.005-1.5 V. The battery test system was the Neware battery test system.

[0053] 0.5C rate test: Discharge (or charge) the battery at 0.5C until the set cut-off voltage (such as 0.005V); record the capacity after multiple charge-discharge cycles at 0.5C.

[0054] Specific capacity calculation: Based on the theoretical capacity of the active material (such as Si-C) or the actual mass of the active material (expressed in mAh / g), divide the discharge capacity obtained by voltage-capacity integration by the weight of the active material.

[0055] 2C rate test: After multiple cycles, increase the rate to 2C; repeat the charge-discharge cycles several times and record its specific capacity and capacity retention rate. Generally, at high rates, the charge-discharge time is significantly shortened (<0.5h), and the capacity measured during this period will decrease to a certain extent compared with that at low rates, indicating increased polarization.

[0056] Capacity retention rate determination: Capacity retention rate = (specific capacity of a certain cycle / specific capacity of the initial cycle) × 100%; after 100 cycles (or the specified number of cycles), comparing the capacity retention rates can evaluate the cycle stability of the material.

[0057] Comparative Example 1

[0058] Omit the graphene, carbon nanotubes, and TiC slurry in Example 1, and keep other process conditions the same as in Example 1.

[0059] Comparative Example 2

[0060] Omit the graphene and TiC slurry in Example 1, and keep other process conditions the same as in Example 1.

[0061] Comparative Example 3

[0062] Omit the TiC slurry in Example 1, and keep other process conditions the same as in Example 1.

[0063] Compared with the negative electrode using only KB (Comparative Example 1), the KB / CNT composite conductive network (Comparative Example 2) significantly reduces the interfacial impedance, with the specific capacity increasing by 10% at 0.5C rate and the capacity retention rate increasing by 5% after 100 cycles.

[0064] The capacity retention rate of the electrode in Comparative Example 3 at 1C rate is 8% higher than that of the electrode without graphene (Comparative Example 2), and at the same time, the impedance spectrum (EIS) shows that the charge transfer impedance is significantly reduced.

[0065] At 2C rate, the specific capacity retention rate of the electrode in Example 1 can still reach over 70%, which is 5% higher than that of the system without adding TiC (Comparative Example 3), proving that TiC enhances the high-rate performance and structural stability.

[0066] Example 2

[0067] 2 g of TiC nanoparticles were treated with 0.025 g of polycarboxylic acid dispersant, and deionized water was added to make up to 100 g. After stirring and dispersing, the pH value of the slurry was adjusted to 10 to reduce the agglomeration of TiC, and a TiC slurry was obtained;

[0068] The mass ratio of Ketjen Black to carbon nanotubes was 1:1, the mass of graphene was 1% of the sum of the masses of conductive carbon black and carbon nanotubes, and the mass of TiC nanoparticles was 1% of the sum of the masses of Ketjen Black and carbon nanotubes;

[0069] Ketjen Black and graphene were added to 300 g of deionized water, and ultrasonic dispersion was carried out at a power of 100 W and a frequency of 40 kHz for 30 min to obtain a mixture; the mixture and carbon nanotubes were continuously ultrasonically dispersed at a power of 100 W for 30 min and then ground in a planetary ball mill at a rate of 300 rpm for 30 min to form a stable KB-graphene-CNT ternary dispersion system; the TiC slurry was slowly added to the ternary dispersion system and ground in a planetary ball mill at a rate of 300 rpm for 30 min to obtain a highly dispersed multi-dimensional conductive network composition.

[0070] 5 g of the multi-dimensional conductive network composition (dry basis), 100 g of Si-C active material (dry basis), and 5 g of PAA / CMC / SBR binder system (dry basis) were mixed in deionized water. The solvent of the PAA / CMC / SBR binder system was water, and the M of PAA w was 400000, the degree of substitution of CMC was 0.8, and in the binder system, the mass fraction ratio of PAA, CMC, and SBR was 1:1:1. Stir and mix, adjust the viscosity to 1500 mPa·s, and coat the mixture on the surface-treated T700 carbon fiber substrate. By setting the doctor blade gap of the coater to 60 μm, a dry film thickness of 25 μm was achieved. After drying at 80 °C for 0.5 h, it was further dried at 120 °C for 1.5 h to remove residual moisture and cure the binder, forming a multi-dimensional conductive network negative electrode layer for integrated structure and energy storage.

[0071] Example 3

[0072] 2 g of TiC nanoparticles were treated with 0.02 g of polycarboxylic acid dispersant, and deionized water was added to make up to 100 g. After stirring and dispersing, the pH value of the slurry was adjusted to 9 to reduce the agglomeration of TiC, and a TiC slurry was obtained;

[0073] The mass ratio of Ketjen Black to carbon nanotubes was 1:1, the mass of graphene was 1.5% of the sum of the masses of conductive carbon black and carbon nanotubes, and the mass of TiC nanoparticles was 3% of the sum of the masses of Ketjen Black and carbon nanotubes;

[0074] Ketjen Black and graphene were added to 300 g of deionized water and ultrasonically dispersed (using an intermittent ultrasonic disperser) at a power of 100 W and a frequency of 40 kHz for 40 min to obtain a mixture. The mixture and carbon nanotubes were shear-mixed at a rate of 7000 rpm for 9 min to form a stable KB-graphene-CNT ternary dispersion system. The TiC slurry was slowly added to the ternary dispersion system and ground in a planetary ball mill at a rate of 350 rpm for 50 min to obtain a highly dispersed multi-dimensional conductive network composition.

[0075] 5 g of the multi-dimensional conductive network composition (dry basis), 100 g of the Si-C active material (dry basis), and 5 g of the PAA / CMC / SBR binder system (dry basis) were mixed in deionized water. The solvent of the PAA / CMC / SBR binder system was water. The M of PAA w was 400,000, the degree of substitution of CMC was 0.75. In the binder system, the mass ratio of PAA, CMC, and SBR was 1:1:1. The mixture was stirred and mixed, and the viscosity was adjusted to 1800 mPa·s. The mixture was coated on a surface-treated T700 carbon fiber substrate. By setting the doctor blade gap of the coater to 60 μm, a dry film thickness of 25 μm was achieved. After drying at 70 °C for 1 h, it was further dried at 120 °C for 1.5 h to remove residual moisture and cure the binder, forming a multi-dimensional conductive network negative electrode layer for integrated structure-energy storage.

[0076] Example 4 Verification of Multi-step Dispersion and Large-scale Production

[0077] To achieve large-scale industrial production, the process of Example 1 was scaled up: a continuous tubular ultrasonic dispersion device (the slurry continuously flowed through the ultrasonic generation area through a pipeline, reducing the interruption in batch operations), a planetary ball mill, and a shear mixing three-step method were used to shorten the production cycle and enable the slurry to form a stable system within 60 min. Online detection (such as particle size detection and viscosity detection) was set at each dispersion or mixing stage. When agglomeration or abnormal fluidity of the slurry was found, the process parameters could be adjusted in a timely manner. Roll-to-roll coating was used to achieve a production speed of several meters per minute, and an infrared / hot air drying system was combined to dry the film in one go. When coating a large area, an online thickness gauge (laser thickness gauge or β-ray thickness gauge) and a surface detection system were required to ensure the electrode uniformity and no obvious pinholes or local agglomeration.

[0078] After large-area electrode coating, tests showed that the capacity retention rate was still as high as over 80% in 300 cycles, and the electrode surface was uniform without obvious local agglomeration, and excellent interfacial integrity was maintained after multiple cycles. The "large-scale industrial production verification" of Example 4 not only inherited the core principle of the small-scale test process, but also ensured the matching of output and quality through equipment upgrading, process scaling-up and process optimization, obtained a stable multi-dimensional conductive network composition, and still had excellent electrochemical performance and interfacial stability after large-area coating.

[0079] The present invention combines Ketjen Black, carbon nanotubes, graphene, and conductive ceramic particles (TiC) in a specific ratio with a multi-step dispersion process to form a continuous and stable three-dimensional conductive framework in the high specific capacity anode material. The method of the present invention significantly improves the electron transfer efficiency of the electrode, reduces local agglomeration, and enhances the structural stability of the electrode under high rate and multi-cycle conditions. The test results show that the multi-dimensional conductive network constructed by the present invention increases the capacity retention rate of the electrode by 5-10% at medium and high rates, increases the specific capacity by 5-10% in the range of 0.5-2C rates, and the capacity retention rate increases by 5-10% after 100-300 cycles, providing high-performance and high-reliability technical support for the structure-energy storage integrated composite material. The method for constructing the multi-dimensional conductive network of the present invention can flexibly adjust the proportion of the conductive agent and the dispersion parameters to adapt to different types of high specific capacity anode materials and different application scenarios.

[0080] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a multi-dimensional conductive network composition with integrated structure and energy storage, characterized in that: The following steps are included: Mixing conductive carbon black, graphene, carbon nanotubes and conductive ceramic particles to obtain a multi-dimensional conductive network composition; The mass ratio of conductive carbon black to carbon nanotubes is 0.8-1.2:0.8-1.2, the mass of graphene is 0.1-2% of the total mass of conductive carbon black and carbon nanotubes, and the mass of conductive ceramic particles is 0.5-5% of the total mass of conductive carbon black and carbon nanotubes.

2. The preparation method according to claim 1, characterized in that: The conductive carbon black is Ketjen Black, and the conductive ceramic particles are TiC.

3. The preparation method according to claim 1 or 2, characterized in that: The mixing method includes one or more of ultrasonic dispersion, shear mixing and planetary ball milling; the ultrasonic dispersion time is 10 to 60 minutes, the shear mixing speed is 3000 to 8000 rpm, and the planetary ball milling time is 0.5 to 2 hours.

4. The preparation method according to claim 3, characterized in that: The mixing is a first mixing of conductive carbon black and graphene, a second mixing of the first mixture and carbon nanotubes, and a third mixing of the second mixture and conductive ceramic particles.

5. The preparation method according to claim 4, characterized in that: Conductive ceramic particles, a dispersant and water are mixed to obtain a slurry, and the pH value of the slurry is adjusted before mixing with a second mixture; the pH value of the slurry is adjusted to 8-11.

6. A multi-dimensional conductive network composition with integrated structure and energy storage prepared by the preparation method according to any one of claims 1 to 5.

7. The method for preparing a multidimensional conductive network negative electrode material from the multidimensional conductive network composition with integrated structure and energy storage as claimed in claim 6, characterized in that: The multidimensional conductive network composition, the negative electrode active material and the aqueous binder system are mixed, and the mixed slurry is coated on a carbon fiber substrate to obtain a multidimensional conductive network negative electrode material; The mass of the conductive carbon black, graphene, carbon nanotubes and conductive ceramic particles is 2-10% of the mass of the negative electrode active material.

8. The method according to claim 7, characterized in that The carbon fiber substrate is a surface-modified carbon fiber substrate; the negative electrode active material is Si-C, SiOx or a metal alloy.

9. The multi-dimensional conductive network negative electrode material prepared by the method according to claim 7 or 8.