A lithium battery composite conductive agent and its preparation method

Abstract

This application relates to the field of lithium batteries, and specifically discloses a lithium battery composite conductive agent, which comprises the following components: conductive particles, organic carriers, binders, colloid materials, dispersants, and solvents; the conductive particles include conductive graphite, carbon fiber, and graphene; the organic carrier is one or two of sorbitan trioleate and lecithin; the colloid material is one or two of guar gum, gelatin, or carrageenan; the dispersant is modified carboxymethyl cellulose. This application also discloses a preparation method of the lithium battery composite conductive agent, which comprises the following steps: S1: Prepare modified carboxymethyl cellulose; S2: Prepare a premixed solution; S3: Prepare a mixed slurry; S4: Prepare a conductive mixed solution; S5: Prepare the lithium battery composite conductive agent. This application has the effect of improving the dispersibility among the components in the composite conductive agent.

Description

Technical Field

[0001] The present application relates to the field of lithium batteries, and more specifically, to a lithium battery composite conductive agent and a preparation method thereof. Background Art

[0002] Due to the advantages of high energy density, excellent cycle performance, and low self-discharge rate of lithium-ion batteries, they are widely used in fields such as energy storage, electric vehicles, and electronic products. The active materials of lithium-ion batteries are mostly transition metal oxides or transition metal salts, and most of them are semiconductors or insulators with poor conductivity, which limits the electron migration rate in the battery, restricts the performance, and may cause performance attenuation or failure. Therefore, a conductive agent must be added to improve the conductivity of lithium-ion batteries in order to increase the charge and discharge rate and cycle performance.

[0003] At present, the commonly used lithium battery conductive agents can be divided into traditional conductive agents (such as carbon black, conductive graphite, carbon fiber, etc.) and new conductive agents (such as carbon nanotubes, graphene, and their mixed conductive slurries, etc.). There has been research on making graphite into a composite conductive agent to form a conductive network, but the composite conductive agents reported currently are all mixed in a certain proportion, which is difficult to ensure good contact and dispersion between the components of the composite conductive agent and cannot achieve an ideal conductive effect. Therefore, there is still room for improvement. Summary of the Invention

[0004] In order to improve the dispersibility between the components in the composite conductive agent, the present application provides a lithium battery composite conductive agent and a preparation method thereof.

[0005] In the first aspect, the present application provides a lithium battery composite conductive agent, adopting the following technical solution:

[0006] A lithium battery composite conductive agent, comprising the following components in parts by mass:

[0007] 15 - 20 parts of conductive particles; 0.3 - 0.6 parts of organic carrier; 0.1 - 0.4 parts of binder; 0.5 - 0.7 parts of colloid material; 1 - 2 parts of dispersant; 100 - 120 parts of solvent;

[0008] The conductive particles include conductive graphite, carbon fiber, and graphene;

[0009] The organic carrier is one or two of sorbitan trioleate and lecithin;

[0010] The colloid material is one or two of guar gum, gelatin, or carrageenan;

[0011] The dispersant is modified carboxymethyl cellulose, and the preparation method of the modified carboxymethyl cellulose is as follows: Dissolve carboxymethyl cellulose in water, stir evenly under the protection of nitrogen, then add sodium persulfate - sodium sulfite anhydrous as an initiator, mix evenly, add acrylamide monomer, continue to introduce nitrogen, the reaction temperature is 35 - 45 °C, the reaction time is 2 - 3 h, and finally wash the obtained polymer solution with ethanol, vacuum filter, wash with water and dry to obtain the modified carboxymethyl cellulose.

[0012] By adopting the above technical solution, the conductive graphite has good conductivity and is in a point - contact form with the active material, and can form a certain - scale conductive network structure; the carbon fiber has a linear structure and is easy to form a good conductive network in the electrode, and the contact form between the carbon fiber and the active material is point - line contact; due to its unique flaky structure, the contact between graphene and the active material is point - surface contact. The organic carrier can prevent the solvent from volatilizing too fast, so as to ensure that the dispersibility between the components is not easily affected.

[0013] In this application, the conductive particles are in point - to - point contact between the conductive graphite and the active material, and then the carbon fiber and the active material are in point - to - line contact, filling the gaps between the conductive graphite and the active material. Moreover, due to the point - surface contact between graphene and the active material, the contact area between the conductive agent and the active material is increased, improving the conductive performance of the battery; then, modified carboxymethyl cellulose is used as a dispersant, adsorbing on the surface of the conductive particles to generate steric hindrance, making it difficult for the conductive particles to agglomerate, and thus making the conductive graphite, carbon fiber and graphene evenly dispersed in the active material. At the same time, the dispersion effect of each component in the conductive agent is also improved. And, under the entanglement of the colloid material, the morphology of the conductive particles is supported, making the conductive network formed by the conductive particles more uniform and stable, thereby further improving the conductive performance of the battery.

[0014] Preferably, the conductive agent further comprises the following components in parts by mass:

[0015] Sodium dodecylbenzenesulfonate 0.6 - 1.2 parts.

[0016] By adopting the above technical solution, sodium dodecylbenzenesulfonate can reduce the surface free energy of the conductive particles, making it difficult for the already - dispersed conductive particles to re - aggregate, helping the conductive particles to better contact with the active material, and can construct a conductive network for the lithium - ion battery, which is beneficial to reducing the dosage ratio of the conductive agent, reducing the internal resistance and temperature, and improving the charge - discharge rate and cycle performance.

[0017] Preferably, the organic carrier is composed of sorbitan trioleate and lecithin mixed in a mass ratio of 1:1.2.

[0018] By adopting the above technical solution, under the action of sodium dodecylbenzenesulfonate, sorbitan trioleate and lecithin can more easily penetrate into the channels and voids between the internal aggregates of conductive particles, causing the aggregates between the particles to break, thereby improving the dispersion effect between the conductive particles and being conducive to improving the electrical conductivity of the conductive agent.

[0019] Preferably, the mass ratio of the conductive graphite, carbon fiber and graphene is (1 - 2):(0.8 - 1):(0.4 - 0.6).

[0020] By adopting the above technical solution, the conductive graphite, carbon fiber and graphene with specific ratios cooperate with each other, making the dispersion of the conductive graphite, carbon fiber and graphene more uniform, enabling the conductive network constructed between the conductive particles to exert their respective conductive advantages, being conducive to reducing the dosage of conductive particles, and thus improving the battery capacity.

[0021] Preferably, the particle size of the conductive graphite is 12 - 15 μm, the particle size of the carbon fiber is 8 - 10 μm, and the particle size of the graphene is 100 - 120 nm.

[0022] By adopting the above technical solution, the conductive particles with specific particle sizes contribute to the uniform mixing between the conductive particles and the active substances, achieving a better dispersion state between the conductive particles, and thus making it not easy for the conductive particles to agglomerate, being conducive to improving the electron transfer ability, thereby improving the electrical conductivity of the battery. Moreover, controlling the particle size of the conductive particles within a better range results in a better density between the conductive particles, making it not easy for cracks to occur inside the battery and being conducive to improving the service life of the battery.

[0023] Preferably, the solvent is one or more of terpineol, dimethyl succinate, dimethylformamide, N-methylpyrrolidone and dibutyl phthalate.

[0024] By adopting the above technical solution, using the above substances as solvents is conducive to improving the compatibility between the conductive particles and other components, and helps to improve the electrical conductivity of the conductive agent.

[0025] Preferably, the solvent is composed of terpineol and dimethyl succinate mixed in a mass ratio of 2:1.

[0026] Preferably, the binder is one or more of polytetrafluoroethylene, polyimide, styrene-butadiene copolymer and polyvinylidene fluoride.

[0027] By adopting the above technical solution, using the above substances as binders is conducive to reducing the sinking speed of the conductive agent, improving the dispersion effect of the conductive agent, and can also improve the compatibility between the conductive particles and the active substances, thereby improving the stability of the conductive agent.

[0028] In a second aspect, the present application provides a method for preparing a lithium battery composite conductive agent, adopting the following technical solution: A method for preparing a lithium battery composite conductive agent includes the following steps:

[0029] S1: Dissolve carboxymethyl cellulose in water, stir evenly under the protection of nitrogen, then add sodium persulfate - sodium sulfite anhydrous as an initiator, mix evenly, add acrylamide monomer, continue to introduce nitrogen, the reaction temperature is 35 - 45 °C, the reaction time is 2 - 3 h, and finally wash the obtained polymer solution with ethanol, vacuum filter, wash with water and dry to obtain modified carboxymethyl cellulose;

[0030] S2: Add conductive particles to half of the solvent according to the formula, and after ultrasonic dispersion evenly, obtain a premixed solution;

[0031] S3: Add the organic carrier, modified carboxymethyl cellulose and the other half of the solvent to the premixed solution, disperse evenly to obtain a mixed slurry;

[0032] S4: Add the binder and the colloidal material to the mixed slurry in sequence, and after dispersing evenly, obtain a conductive mixed liquid;

[0033] S5: Transport the conductive mixed liquid to a frosting device, and after frosting treatment, obtain a lithium battery composite conductive agent.

[0034] By adopting the above technical solution, the lithium battery conductive agent prepared by the above method has good dispersion performance and conductivity, and moreover, the production process of this method is simple, which is beneficial to industrial production.

[0035] In summary, the present application includes at least one of the following beneficial technical effects:

[0036] 1. By adopting the point - to - point contact between conductive graphite and the active material, then the point - to - line contact between carbon fiber and the active material to fill the gaps between the conductive graphite and the active material in contact, and moreover, due to the point - to - surface contact between graphene and the active material, the contact area between the conductive agent and the active material is increased, so that the conductivity of the battery is improved; then use modified carboxymethyl cellulose as a dispersant, which adsorbs on the surface of the conductive particles to generate steric hindrance, making it difficult for the conductive particles to agglomerate, and further making the conductive graphite, carbon fiber and graphene evenly dispersed in the active material. And under the entanglement of the colloidal material, the morphology of the conductive particles is supported, making the conductive network formed by the conductive particles more uniform and stable, thereby improving the conductivity of the battery.

[0037] 2. The conductive particles have a specific particle size, which helps to uniformly mix the conductive particles with the active material, enabling the conductive particles to achieve a better dispersion state, improving the electron transport ability, thereby enhancing the conductivity of the battery. Moreover, with small particle size and good density, cracks are not easily generated inside the battery, making it not prone to breakage at high temperatures, which is beneficial to extending the service life of the battery.

[0038] 3. By using sodium dodecylbenzenesulfonate in combination with sorbitan trioleate and lecithin, sorbitan trioleate and lecithin can more easily penetrate into the channels and voids between the internal aggregates of the conductive particles, causing the aggregates between the particles to break, thereby improving the dispersion effect between the conductive particles, which is beneficial to enhancing the conductivity of the conductive agent. Description of the Drawings

[0039] Figure 1 It is a schematic diagram of the steps of a preparation method of a lithium battery composite conductive agent in this application.

[0040] Figure 2 It is a discharge cycle curve graph of the lithium battery in Example 3 of this application at a temperature of 60 °C and a charge-discharge rate of 1C. Detailed Embodiments

[0041] The following further elaborates on this application in conjunction with embodiments.

[0042] Example 1

[0043] This example discloses a lithium battery composite conductive agent, which includes the following components:

[0044] Conductive particles; organic carrier; binder; colloid material; dispersant; solvent;

[0045] The conductive particles include conductive graphite, carbon fiber, and graphene. Among them, the particle size of the conductive graphite is 10 μm, the particle size of the carbon fiber is 5 μm, and the particle size of the graphene is 100 nm; the organic carrier is sorbitan trioleate; the colloid material is guar gum and gelatin; the dispersant is modified carboxymethyl cellulose; the binder is polytetrafluoroethylene; the solvent is dimethylformamide.

[0046] This example also discloses a preparation method of a lithium battery composite conductive agent, which includes the following steps:

[0047] S1: Dissolve carboxymethyl cellulose in deionized water, stir evenly under the protection of nitrogen, then add sodium persulfate-sodium metabisulfite (concentration of 350 mg / L) as an initiator, mix evenly, add acrylamide monomer, continue to introduce nitrogen, the reaction temperature is 35 °C, the reaction time is 2 h, and finally wash the obtained polymer solution with ethanol, vacuum filter, rinse with deionized water, and dry to obtain modified carboxymethyl cellulose;

[0048] S2: Add conductive particles into half of the solvent according to the formula (specific dosages are shown in Table 1). After ultrasonic dispersion until evenly mixed, a pre-mixed solution is obtained. The frequency of ultrasonic dispersion is 40KHz, and the time of ultrasonic dispersion is 30min;

[0049] S3: Add the organic carrier, modified carboxymethyl cellulose, and the other half of the solvent into the pre-mixed solution (specific dosages are shown in Table 1), and disperse evenly at a rotation speed of 350r / min to obtain a mixed slurry;

[0050] S4: Add the binder and the colloidal material (specific dosages are shown in Table 1) into the mixed slurry in sequence, and stir evenly at a rotation speed of 380r / min to obtain a conductive mixed solution;

[0051] S5: Transport the conductive mixed solution to a frosting device. After frosting treatment, a lithium battery composite conductive agent is obtained. The frosting treatment time is 5h, and the treatment temperature is 60°C.

[0052] Example 2

[0053] The difference from Example 1 is:

[0054] S1: Dissolve carboxymethyl cellulose in deionized water, stir evenly under the protection of nitrogen, then add sodium persulfate-sodium metabisulfite (concentration is 300mg / L) as an initiator, mix evenly, add acrylamide monomer, continue to introduce nitrogen, the reaction temperature is 45°C, and the reaction time is 3h. Finally, wash the obtained polymer solution with ethanol, vacuum filter, rinse with deionized water, and dry to obtain modified carboxymethyl cellulose;

[0055] S5: Transport the conductive mixed solution to a frosting device. After frosting treatment, a lithium battery composite conductive agent is obtained. The frosting treatment time is 3h, and the treatment temperature is 50°C.

[0056] Example 3

[0057] The difference from Example 1 is:

[0058] S1: Dissolve carboxymethyl cellulose in deionized water, stir evenly under the protection of nitrogen, then add sodium persulfate-sodium metabisulfite (concentration is 320mg / L) as an initiator, mix evenly, add acrylamide monomer, continue to introduce nitrogen, the reaction temperature is 40°C, and the reaction time is 2.5h. Finally, wash the obtained polymer solution with ethanol, vacuum filter, rinse with deionized water, and dry to obtain modified carboxymethyl cellulose;

[0059] S5: Transport the conductive mixed solution to a frosting device. After frosting treatment, a lithium battery composite conductive agent is obtained. The frosting treatment time is 4h, and the treatment temperature is 55°C.

[0060] The dosages of each component in Examples 1 - 3 are shown in Table 1, and the unit of dosage in Table 1 is kg.

[0061] Table 1

[0062]

[0063]

[0064] Example 4

[0065] The difference from Example 3 is that 0.6 kg of sodium dodecylbenzenesulfonate is further added in S3.

[0066] Example 5

[0067] The difference from Example 3 is that 1.2 kg of sodium dodecylbenzenesulfonate is further added in S3.

[0068] Example 6

[0069] The difference from Example 5 is that the organic carrier is composed of a mixture of sorbitan trioleate and lecithin with a mass ratio of 1:1.2.

[0070] Example 7

[0071] The difference from Example 5 is that the organic carrier is composed of a mixture of sorbitan trioleate and lecithin with a mass ratio of 2:1.

[0072] Example 8

[0073] The difference from Example 6 is that lecithin is replaced with an equal amount of sorbitan trioleate.

[0074] Example 9

[0075] The difference from Example 6 is that sorbitan trioleate is replaced with an equal amount of lecithin.

[0076] Example 10

[0077] The difference from Example 3 is that the mass ratio of conductive graphite, carbon fiber, and graphene is 1:0.8:0.4; the particle size of conductive graphite is 12 μm, the particle size of carbon fiber is 8 μm, and the particle size of graphene is 100 nm.

[0078] Example 11

[0079] The difference from Example 3 is that the mass ratio of conductive graphite, carbon fiber, and graphene is 2:1:0.6; the particle size of conductive graphite is 15 μm, the particle size of carbon fiber is 10 μm, and the particle size of graphene is 120 nm.

[0080] Example 12

[0081] The differences from Example 3 are as follows: the mass ratio of conductive graphite, carbon fiber, and graphene is 2:1:0.6; the particle size of conductive graphite is 15 μm, the particle size of carbon fiber is 10 μm, and the particle size of graphene is 120 nm; 1.2 kg of sodium dodecylbenzenesulfonate is also added in S3; the organic carrier is composed of sorbitan trioleate and lecithin mixed in a mass ratio of 1:1.2; the solvent is composed of terpineol and dimethyl succinate mixed in a mass ratio of 2:1.

[0082] Comparative Example 1

[0083] The difference from Example 3 is that the dispersant is unmodified carboxymethyl cellulose.

[0084] Comparative Example 2

[0085] The difference from Example 3 is that no conductive graphite is added in S2.

[0086] Comparative Example 3

[0087] The difference from Example 3 is that no carbon fiber is added in S2.

[0088] Comparative Example 4

[0089] The difference from Example 3 is that no graphene is added in S2.

[0090] Comparative Example 5

[0091] The difference from Example 3 is that an equal amount of carbon nanotubes is used to replace graphene.

[0092] Comparative Example 6

[0093] The difference from Example 3 is that an equal amount of xanthan gum is used to replace guar gum and gelatin.

[0094] Comparative Example 7

[0095] The difference from Example 3 is that:

[0096] A lithium battery composite conductive agent, comprising the following components in parts by mass:

[0097] 10 kg of conductive particles; 0.1 kg of organic carrier; 2 kg of binder; 1 kg of colloidal material; 3 kg of dispersant; 90 kg of solvent.

[0098] Experiment 1

[0099] In this experiment, the performances of the composite conductive agents prepared in Example 3 and Comparative Example 1 were respectively detected, and the detection results are shown in Table 2.

[0100] Table 2

[0101]

[0102]

[0103] According to the experimental results in Table 2, it can be seen that the composite conductive agent prepared in Example 3 meets the detection standard.

[0104] Experiment 2

[0105] The conductive agents prepared in Examples 1-12 and Comparative Examples 1-7 were used in the positive electrode paste to prepare lithium batteries, which were respectively labeled as Specimens 1-19, and then the high-temperature cycle performance of the lithium batteries was detected respectively. The test method is as follows:

[0106] At 60 °C, charging was carried out in a constant current and constant voltage charging mode, with a limiting current of 0.5C, a termination voltage of 3.65V, and a termination current of 3.5A. Discharging was carried out in a constant current discharging mode, with a discharging current of 1C, and a discharging cut-off voltage of 2.5 volts. After 2000 cycles, the initial discharge capacity C1 (mAh), the discharge capacity C2 (mAh) after 2000 cycles, and the capacity retention rate R (%) after 2000 cycles were calculated respectively.

[0107] R = 1 - [(C1 - C2) / C1] × 100%.

[0108] Experiment 3

[0109] In this experiment, according to the measurement method of the conductivity of non-ferrous metal materials in JISH0505-1975, the conductivity (S / m) of Specimens 1-19 (corresponding to Examples 1-12 and Comparative Examples 1-7 respectively) was detected.

[0110] The experimental data of Experiment 2 and Experiment 3 are shown in Table 3.

[0111] Table 3

[0112]

[0113]

[0114] According to the comparison of the data of Specimens 13 - 17 in Table 3 with the data of Specimen 3 respectively, it can be obtained that in Specimen 13, carboxymethyl cellulose was not modified; in Specimen 14, conductive graphite was not added; in Specimen 15, carbon fiber was not added; in Specimen 16, graphene was not added. The conductivity of Specimens 13 - 16 was basically close. Compared with Specimens 13 - 16, the conductivity of Specimen 3 increased from about 13 S / m to 16.7 S / m, indicating that using conductive graphite, carbon fiber, and graphene as conductive particles and modifying carboxymethyl cellulose is beneficial to improving the conductivity of lithium batteries. In Specimen 17, carbon nanotubes were used in combination with conductive graphite and carbon fiber, and the conductivity of the lithium battery was much lower than that of Specimen 3, indicating that using carbon nanotubes in combination with conductive graphite and carbon fiber not only cannot improve the conductivity of the lithium battery but also reduces it. This is because whether carbon nanotubes are in an entangled growth state or an array growth state, it is very difficult to disperse them evenly with conductive graphite and carbon fiber, thus affecting the conductivity of the lithium battery.

[0115] According to the comparison of the data of Specimen 18 in Table 3 with the data of Specimen 3, it can be obtained that in Specimen 18, xanthan gum was used to replace guar gum and gelatin as the organic carrier, and the conductivity was 12.4 S / m, while the conductivity of Specimen 3 was 16.7 S / m, indicating that not any organic carrier can improve the conductivity of lithium batteries.

[0116] According to the data of Specimen 19 and Specimen 3 in Table 3, it can be obtained that the dosage of each component in Specimen 19 was outside the dosage range of this application, and the conductivity was 11.8 S / m. Compared with Specimen 19, the conductivity of Specimen 3 increased by 4.9 S / m, indicating that not any ratio of each component in the conductive agent can achieve the effect of this application (improving the conductivity of lithium batteries).

[0117] According to the comparison of the data of Specimens 4 - 5 in Table 3 with Specimen 3 respectively, it can be obtained that in Specimen 5, sodium dodecylbenzenesulfonate was added on the basis of Specimen 3. The conductivity was 20.3 S / m, and the capacity retention rate was 83%. Compared with Specimen 3, the conductivity increased by 3.6 S / m, and the capacity retention rate increased by 10%. This indicates that adding sodium dodecylbenzenesulfonate is not only beneficial to improving the conductive performance of lithium batteries but also improves the high-temperature cycle performance of lithium batteries. This is because sodium dodecylbenzenesulfonate can reduce the surface free energy of conductive particles, making it not easy for the dispersed conductive particles to re-aggregate, which helps the conductive particles better contact with the active substances, thus improving the performance of the lithium battery.

[0118] According to the data of specimens 6-9 in Table 3 compared with specimen 3 respectively, sorbitan trioleate was added alone in specimen 8, and lecithin was added alone in specimen 9, and the conductivity of specimen 8 and specimen 9 was basically close; while in specimen 6, the organic carrier was composed of a mixture of sorbitan trioleate and lecithin with a mass ratio of 1:1.2, and the conductivity increased from about 19 S / m to 21.8 S / m, indicating that the organic carrier composed of a mixture of sorbitan trioleate and lecithin with a mass ratio of 1:1.2 is beneficial to improving the conductivity of lithium batteries.

[0119] The above are all preferred embodiments of this application, and the protection scope of this application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A lithium battery composite conductive agent, characterized in that: It includes components in the following parts by mass: 15 - 20 parts of conductive particles; 0.3 - 0.6 part of organic carrier; 0.1 - 0.4 part of binder; 0.5 - 0.7 part of colloidal material; 1 - 2 parts of dispersant; 100 - 120 parts of solvent; the solvent is composed of terpineol and dimethyl succinate mixed in a mass ratio of 2:1; The conductive particles include conductive graphite, carbon fiber and graphene; the mass ratio of conductive graphite, carbon fiber and graphene is (1 - 2):(0.8 - 1):(0.4 - 0.6); the particle size of conductive graphite is 12 - 15 μm, the particle size of the carbon fiber is 8 - 10 μm, and the particle size of the graphene is 100 - 120 nm; The organic carrier is one or both of sorbitan trioleate and lecithin; The colloidal material is one or both of guar gum, gelatin or carrageenan; The dispersant is modified carboxymethyl cellulose, and the preparation method of modified carboxymethyl cellulose is as follows: dissolve carboxymethyl cellulose in water, stir evenly under the protection of nitrogen, then add sodium persulfate - sodium sulfite as initiator, mix evenly, then add acrylamide monomer, continue to introduce nitrogen, the reaction temperature is 35 - 45 °C, the reaction time is 2 - 3 h, and finally wash the obtained polymer solution with ethanol, vacuum filter, wash with water and dry to obtain modified carboxymethyl cellulose; The preparation method is as follows: S1: Dissolve carboxymethyl cellulose in water, stir evenly under the protection of nitrogen, then add sodium persulfate - sodium sulfite as initiator, mix evenly, then add acrylamide monomer, continue to introduce nitrogen, the reaction temperature is 35 - 45 °C, the reaction time is 2 - 3 h, and finally wash the obtained polymer solution with ethanol, vacuum filter, wash with water and dry to obtain modified carboxymethyl cellulose; S2: Add conductive particles to half of the amount of solvent according to the formula, and after ultrasonic dispersion evenly, obtain a premixed solution; S3: Add the organic carrier, modified carboxymethyl cellulose and the other half of the amount of solvent to the premixed solution, disperse evenly to obtain a mixed slurry; S4: Add the binder and the colloidal material to the mixed slurry in sequence, disperse evenly to obtain a conductive mixed liquid; S5: Transport the conductive mixed liquid to a grinding device, and obtain a lithium battery composite conductive agent after grinding treatment.

2. The lithium battery composite conductive agent according to claim 1, characterized in that: The conductive agent also includes components in the following parts by mass: 0.6 - 1.2 parts of sodium dodecylbenzenesulfonate.

3. The lithium battery composite conductive agent according to claim 2, wherein: The organic carrier is composed of sorbitan trioleate and lecithin mixed in a mass ratio of 1:1.

2.

4. The composite conductive agent for lithium battery according to claim 1, wherein: The binder is one or more of polytetrafluoroethylene, polyimide, styrene - butadiene copolymer and polyvinylidene fluoride.

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