A negative electrode paste for lead-carbon batteries and its preparation method

Abstract

This invention relates to the field of negative electrode materials for storage batteries, and discloses a lead paste for negative electrodes of lead-carbon storage batteries and its preparation method. The lead paste comprises the following raw materials by mass: 360-410 parts of β-lead oxide, 590-640 parts of α-lead oxide powder, 3-5 parts of mixed carbon, 10-15 parts of barium sulfate, 1-3 parts of humic acid, 1-3 parts of sodium lignosulfonate, 0.5-1 part of hydrophobic hydrogen inhibitor, 0.5 parts of vanillin, 1-2 parts of conductive fiber, 40-45 parts of sulfuric acid, 5-10 parts of additives, and the balance of pure water. This application uses additives with specific composition and proportions, wherein the hydrophobic hydrogen inhibitor, in combination with the additives, can significantly improve battery performance. The surface-modified hydrophobic hydrogen inhibitor is uniformly dispersed on the hydrophobic crosslinking network and acts as a pore-forming agent for the hydrophobic crosslinking network, significantly enhancing the hydrogen-oxygen recombination effect of the hydrophobic crosslinking network, significantly reducing the hydrogen evolution and water loss of the storage battery, thereby greatly improving battery life.

Description

Technical Field

[0001] This invention relates to the field of negative electrode materials for lead-carbon batteries, and in particular to a lead paste for negative electrodes of lead-carbon batteries and its preparation method. Background Technology

[0002] Lead-carbon batteries are a new type of battery that combines supercapacitors with lead-acid batteries. They possess advantages such as large capacity, good cycle performance, high initial capacity, and high fast charge / discharge performance, and have gradually become the mainstay of the electric vehicle industry. Although lead-carbon batteries have many advantages, they also have the following problems during use: The active materials on the negative electrode undergo significant volume changes during interconversion; the higher the degree of conversion, the higher the rate of volume change. This leads to the collapse and detachment of the active materials on the negative electrode during deep charge / discharge. Furthermore, the active materials on the negative electrode also experience excessive hydrogen evolution and water loss during the conversion process. The large amount of hydrogen produced impacts the structure of the active materials, accelerating their collapse. Excessive hydrogen evolution also leads to water loss in the battery. All of these problems significantly reduce the battery's lifespan.

[0003] To address the aforementioned problems, existing technologies have provided numerous solutions, such as the lead-acid battery negative electrode paste and its preparation method disclosed in CN 113540424 A. This method adds a compounding acid to the raw materials. This compounding acid is an emulsion formed from polytetrafluoroethylene-acrylic acid and sulfuric acid. This compounding acid can form a hydrophobic cross-linked network in the lead paste, promoting oxygen and hydrogen recombination and reducing battery water loss. Simultaneously, the carboxyl groups on the polymer molecules complex with lead powder, further enhancing the bonding strength between the cross-linked network and the active material. While the above methods can reduce the collapse and shedding of the negative electrode active material and hydrogen evolution to some extent, this application finds that the method introduces hydrophobic substances. Since the hydrogen evolution agent in the lead paste raw materials is usually a highly hydrophilic metal oxide, it is repelled by the hydrophobic substances during the paste-making process, forming agglomerates. This significantly reduces the dispersibility in the lead paste system, resulting in poor hydrogen evolution performance. Therefore, to solve this problem, this application provides a new lead-carbon battery negative electrode paste and its preparation method. Summary of the Invention

[0004] To overcome the aforementioned problems, this application provides a lead-carbon battery negative electrode paste and its preparation method. The negative electrode paste uses additives with specific composition and proportion, which can fully disperse the hydrogen inhibitor in the hydrophobic cross-linked network formed by the additives. This can significantly improve the hydrogen inhibition effect of the hydrogen inhibitor in the negative electrode paste, significantly suppress the hydrogen evolution and water loss of the battery negative electrode, and significantly improve battery performance.

[0005] The specific technical solution of this invention is as follows:

[0006] A negative electrode paste for lead-carbon batteries, characterized in that it comprises the following raw materials by weight: 360-410 parts β-lead oxide, 590-640 parts α-lead oxide powder, 3-5 parts mixed carbon, 10-15 parts barium sulfate, 1-3 parts humic acid, 1-3 parts sodium lignin sulfonate, 0.5-1 part hydrophobic hydrogen inhibitor, 0.5 parts vanillin, 1-2 parts conductive fiber, 40-45 parts sulfuric acid, 5-10 parts additives, and the balance being pure water.

[0007] In the formulation of the negative electrode lead paste of this application, the functions of each raw material are as follows:

[0008] Mixed carbon: adsorbs active substances to form a conductive network, enhances the conductivity of the negative electrode, and prevents lead sulfate from failing to convert into spongy metallic lead after excessive cycling;

[0009] Barium sulfate: as a nucleating agent and swelling agent for lead sulfate, it inhibits the passivation of negative electrode active materials;

[0010] Sodium lignosulfonate and humic acid: act as swelling agents to inhibit the volume change of active substances;

[0011] Hydrophobic hydrogen inhibitor: Inhibits hydrogen evolution in battery electrolyte and reduces battery water loss;

[0012] Additives: Form a hydrophobic cross-linked network, reduce battery water loss, reduce the collapse and shedding of negative electrode active material, and enhance battery performance.

[0013] The negative electrode lead paste provided in this application uses additives with specific composition and proportion as raw materials. The hydrophobic hydrogen inhibitor, in combination with the additives, can fully disperse the hydrophobic hydrogen inhibitor in the cross-linked network formed by the additives. This can significantly inhibit hydrogen evolution and water loss in the negative electrode lead paste, significantly improve battery performance, and compared with commercially available batteries, have a longer cycle life, faster charging speed, and higher capacity at room temperature and low temperature.

[0014] Preferably, the mixed carbon comprises one or more of acetylene black, activated carbon, carbon black, and graphene.

[0015] Preferably, the conductive fiber comprises polyurethane fiber and / or polyacrylonitrile fiber.

[0016] Preferably, the additive is a tetrafluoroethylene-acrylic acid copolymer, and the mass ratio of the tetrafluoroethylene-acrylic acid copolymer is 3~4:1.

[0017] Preferably, the hydrophobic hydrogen inhibitor includes bismuth oxide and a hydrophobic modifier, and the preparation method of the hydrophobic hydrogen inhibitor includes: accelerating bismuth oxide and passing it through droplets formed by the hydrophobic modifier, followed by solidification to obtain the hydrophobic hydrogen inhibitor.

[0018] The hydrogen inhibitor in this application is bismuth oxide, a metal oxide. The surface of metal oxides exhibits capillary action, thus possessing strong hydrophilicity. This application uses a hydrophobic modifier to hydrophobically modify the bismuth oxide, significantly increasing its hydrophobicity. Furthermore, this application partially modifies the surface of bismuth oxide during the preparation of the hydrophobic hydrogen inhibitor, making the modified bismuth oxide surface hydrophobic while the unmodified surface is hydrophilic. The hydrophobic surface is miscible with the hydrophobic auxiliary emulsion particles, while the hydrophilic side is miscible with water. After mixing the auxiliary, bismuth oxide, and water, the auxiliary first forms emulsion particles, while the bismuth oxide is embedded in these particles on one side and dissolved in water on the other, forming a unique emulsion form.

[0019] When preparing lead paste using the emulsion formed by the above-mentioned hydrophobic hydrogen inhibitor, additives, and water, the additives form a cross-linked hydrophobic network, and the hydrophobic hydrogen inhibitor is uniformly dispersed on the cross-linked hydrophobic network. At the same time, part of the hydrophobic hydrogen inhibitor is embedded in the cross-linked network, while another part is exposed outside the cross-linked network. In addition, since part of the surface of the hydrophobic hydrogen inhibitor is not modified, it has strong hydrophilicity and can also form a pore-forming effect on the cross-linked network, which can form a tiny pore structure on the cross-linked network, significantly enhancing the hydrogen-oxygen recombination effect of the hydrophobic cross-linked network, effectively reducing battery water loss, and significantly improving the cycle life of the battery.

[0020] Furthermore, the hydrophobic modifier includes one or more of trimethylchlorosilane, thiophenol, and 1,3-propanedithiol.

[0021] A method for preparing lead paste for the negative electrode of a lead-carbon battery includes the following steps:

[0022] (1) Add β-lead oxide and pure water to the reaction vessel and stir. After stirring, add sulfuric acid dropwise and heat to obtain initial lead paste. Vacuum dry the initial lead paste and grind it to make initial lead powder.

[0023] (2) Add the additives and hydrophobic hydrogen inhibitors to pure water to make an emulsion;

[0024] (3) Place the initial lead powder obtained in step (1) into a paste mixing machine and add α-lead oxide, mixed carbon, barium sulfate, humic acid, sodium lignin sulfonate, conductive fiber and vanillin in sequence and mix evenly. Then add the emulsion obtained in step (2) and stir evenly to obtain negative electrode lead paste.

[0025] Preferably, the stirring time in step (1) is 5~15 min; the heating temperature is 50~70℃ and the heating time is 1~2 h; the vacuum drying temperature is 60~70℃ and the vacuum drying time is 3~5 h; the moisture content of the initial lead powder is less than 0.5% and the average particle size of the initial lead powder is 1~2 μm.

[0026] A storage battery comprising a negative electrode made of the aforementioned negative electrode lead paste.

[0027] An electric vehicle, including the aforementioned battery.

[0028] Compared with the prior art, this application has the following technical effects:

[0029] (1) This application uses additives with specific composition and ratio. The hydrophobic hydrogen inhibitor added in combination with the auxiliary agent can significantly improve battery performance.

[0030] (2) The surface of the hydrophobic hydrogen inhibitor of this application has been partially modified so that part of the bismuth oxide surface is hydrophobic and the other part is hydrophilic. The hydrophobic surface and the hydrophobic cross-linking network formed by the additive are partially intercalated and uniformly dispersed on the hydrophobic cross-linking network. At the same time, the hydrophilic surface can act as a pore-forming agent for the hydrophobic cross-linking network, so that the hydrophobic cross-linking network forms a porous structure, significantly enhancing the hydrogen-oxygen recombination effect of the hydrophobic cross-linking network, significantly reducing the hydrogen evolution and water loss of the battery, thereby greatly improving the battery life. Detailed Implementation

[0031] The present invention will be further described below with reference to embodiments.

[0032] General Implementation Examples:

[0033] A lead-carbon battery negative electrode paste comprises the following raw materials by weight: 360-410 parts β-lead oxide, 590-640 parts α-lead oxide powder, 3-5 parts mixed carbon, 10-15 parts barium sulfate, 1-3 parts humic acid, 1-3 parts sodium lignin sulfonate, 0.5-1 part hydrophobic hydrogen inhibitor, 0.5 parts vanillin, 1-2 parts conductive fiber, 40-45 parts sulfuric acid, 5-10 parts additives, and the balance being pure water.

[0034] The mixed carbon comprises one or more of acetylene black, activated carbon, carbon black, and graphene; the specific surface area of ​​the mixed carbon is 1000 m². 2 / g; the conductivity of the pure water is 1 μS / cm;

[0035] The conductive fibers include polyurethane fibers and / or polyacrylonitrile fibers;

[0036] The additive is a tetrafluoroethylene-acrylic acid copolymer, and the mass ratio of the tetrafluoroethylene-acrylic acid copolymer is 3~4:1;

[0037] The hydrophobic hydrogen inhibitor includes bismuth oxide and a hydrophobic modifier.

[0038] The hydrophobic modifier includes one or more of trimethylchlorosilane, thiophenol, and 1,3-propanedithiol;

[0039] A method for preparing lead paste for the negative electrode of a lead-carbon battery includes the following steps:

[0040] (1) Add 360-410 parts of β-lead oxide and 1100-1300 parts of pure water to a reaction vessel and stir for 5-15 minutes. After stirring, add 40-45 parts of sulfuric acid (density 1.4 g / ml) dropwise at room temperature and heat to 50-70℃ and keep warm for 1-2 hours. Filter and separate to obtain initial lead paste. Place the initial lead paste in a vacuum dryer and vacuum dry at 60-70℃ to obtain initial lead powder (average particle size 1-2 μm, moisture content less than 0.5%).

[0041] (2) Add 5-10 parts of the additive to 100-110 parts of pure water to make high-speed stirring, and then add 0.5-1 parts of hydrophobic hydrogen inhibitor and continue stirring to make an emulsion; the preparation method of the hydrophobic hydrogen inhibitor includes: accelerating bismuth oxide and passing it through droplets formed by the hydrophobic modifier and then solidifying it to obtain the hydrophobic hydrogen inhibitor.

[0042] (3) Place the initial lead powder obtained in step (1) into a paste mixing machine and add 590-640 parts of α-lead oxide, 3-5 parts of mixed carbon, 10-15 parts of barium sulfate, 1-3 parts of humic acid, 1-3 parts of sodium lignin sulfonate, 1-2 parts of conductive fiber, and 0.5 parts of vanillin. Dry mix for 10-15 minutes. After mixing evenly, add the emulsion obtained in step (2) and stir for 10-15 minutes to obtain negative electrode lead paste.

[0043] A storage battery includes a negative electrode made from the negative electrode paste.

[0044] An electric vehicle, including the aforementioned battery.

[0045] Example 1:

[0046] A negative electrode paste for lead-carbon batteries comprises the following raw materials by weight: 360 parts β-lead oxide, 590 parts α-lead oxide powder, 3 parts acetylene black, 10 parts barium sulfate, 1 part humic acid, 1 part sodium lignosulfonate, 0.5 parts hydrophobic hydrogen inhibitor, 0.5 parts vanillin, 1 part polyurethane fiber, 40 parts sulfuric acid, 5 parts tetrafluoroethylene-acrylic acid copolymer (mass ratio 3:1), and the balance being pure water.

[0047] A method for preparing lead paste for the negative electrode of a lead-carbon battery includes the following steps:

[0048] (1) Add 360 parts of β-lead oxide and 1100 parts of pure water to the reaction vessel and stir for 5 min. After stirring, add 40 parts of sulfuric acid (density 1.4 g / ml) dropwise at room temperature and heat to 50℃ and keep warm for 1 h. Filter and separate to obtain initial lead paste. Place the initial lead paste in a vacuum dryer and vacuum dry at 60℃ to obtain initial lead powder (average particle size 1 μm, moisture content less than 0.5%).

[0049] (2) Add 5 parts of the additive to 100 parts of pure water and stir at high speed, then add 0.3 parts of trimethylchlorosilane and 0.2 parts of thiophenol and continue stirring to form an emulsion; the preparation method of the hydrophobic hydrogen inhibitor includes: placing bismuth oxide in a high-speed gas flow for acceleration, spraying the accelerated bismuth oxide through droplets formed by the hydrophobic modifier and then solidifying it to obtain the hydrophobic hydrogen inhibitor;

[0050] (3) Place the initial lead powder obtained in step (1) into a paste mixing machine and add 590-640 parts of α-lead oxide, 3 parts of acetylene black, 10 parts of barium sulfate, 1 part of humic acid, 1 part of sodium lignosulfonate, 1 part of polyurethane fiber, and 0.5 parts of vanillin in sequence. Dry mix for 10 minutes. After mixing evenly, add the emulsion obtained in step (2) and stir for 10 minutes to obtain negative electrode lead paste.

[0051] Example 2:

[0052] A lead-carbon battery negative electrode paste comprises the following raw materials by weight: 385 parts β-lead oxide, 615 parts α-lead oxide powder, 3 parts acetylene black, 1 part graphene, 12.5 parts barium sulfate, 2 parts humic acid, 2 parts sodium lignosulfonate, 0.75 parts hydrophobic hydrogen inhibitor, 0.5 parts vanillin, 0.5 parts polyurethane fiber, 0.5 parts polyacrylonitrile fiber, 42 parts sulfuric acid, 7 parts tetrafluoroethylene-acrylic acid copolymer (mass ratio 3:1), and the balance being pure water.

[0053] (1) Add 385 parts of β-lead oxide and 1200 parts of pure water to the reaction vessel and stir for 10 min. After stirring, add 42 parts of sulfuric acid (density 1.4 g / ml) dropwise at room temperature and heat to 60℃ and keep warm for 1.5 h. Filter and separate to obtain initial lead paste. Place the initial lead paste in a vacuum dryer and vacuum dry at 65℃ to obtain initial lead powder (average particle size 1~2 μm, moisture content less than 0.5%).

[0054] (2) Add 7 parts of tetrafluoroethylene-acrylic acid copolymer (mass ratio of 3:1) to 105 parts of pure water and stir at high speed, then add 0.3 parts of trimethylchlorosilane and 0.45 parts of thiophenol and continue stirring to form an emulsion; the preparation method of the hydrophobic hydrogen inhibitor includes: accelerating bismuth oxide and passing it through droplets formed by the hydrophobic modifier and then solidifying it to obtain the hydrophobic hydrogen inhibitor;

[0055] (3) Place the initial lead powder obtained in step (1) into a paste mixing machine and add 615 parts of α-lead oxide, 3 parts of acetylene black, 1 part of graphene, 12.5 parts of barium sulfate, 2 parts of humic acid, 2 parts of sodium lignosulfonate, 0.5 parts of vanillin, 0.5 parts of polyurethane fiber, and 0.5 parts of polyacrylonitrile fiber in sequence. Dry mix for 10-15 minutes. After mixing evenly, add the emulsion obtained in step (2) and stir for 13 minutes to obtain negative electrode lead paste.

[0056] Example 3:

[0057] A lead-carbon battery negative electrode paste comprises the following raw materials by weight: 410 parts β-lead oxide, 640 parts α-lead oxide powder, 3 parts acetylene black, 1 part carbon black, 0.7 parts graphene, 0.3 parts activated carbon, 15 parts barium sulfate, 3 parts humic acid, 3 parts sodium lignosulfonate, 1 part hydrophobic hydrogen inhibitor, 0.5 parts vanillin, 1 part polyurethane fiber, 1 part polyacrylonitrile fiber, 45 parts sulfuric acid, 10 parts tetrafluoroethylene-acrylic acid copolymer (mass ratio 4:1), and the balance being pure water.

[0058] A method for preparing lead paste for the negative electrode of a lead-carbon battery includes the following steps:

[0059] (1) Add 410 parts of β-lead oxide and 1300 parts of pure water to the reaction vessel and stir for 15 min. After stirring, add 45 parts of sulfuric acid (density 1.4 g / ml) dropwise at room temperature and heat to 70℃ and keep warm for 2 h. Filter and separate to obtain initial lead paste. Place the initial lead paste in a vacuum dryer and vacuum dry at 70℃ to obtain initial lead powder (average particle size 1~2 μm, moisture content less than 0.5%).

[0060] (2) 10 parts of tetrafluoroethylene-acrylic acid copolymer (mass ratio of 4:1) were added to 110 parts of pure water and stirred at high speed. Then, 0.3 parts of trimethylchlorosilane, 0.45 parts of thiophenol and 0.25 parts of 1,3-propanedithiol were added and stirred to form an emulsion. The preparation method of the hydrophobic hydrogen inhibitor includes the following steps: bismuth oxide is accelerated and passed through droplets formed by the hydrophobic modifier and then solidified to obtain the hydrophobic hydrogen inhibitor.

[0061] (3) Place the initial lead powder obtained in step (1) into a paste mixing machine and add 640 parts of α-lead oxide, 3 parts of acetylene black, 1 part of carbon black, 0.7 parts of graphene, 0.3 parts of activated carbon, 15 parts of barium sulfate, 3 parts of humic acid, 3 parts of sodium lignosulfonate, 1 part of polyurethane fiber, 1 part of polyacrylonitrile fiber, and 0.5 parts of vanillin. Dry mix for 15 minutes. After mixing evenly, add the emulsion obtained in step (2) and stir for 15 minutes to obtain negative electrode lead paste.

[0062] Comparative Example 1:

[0063] Comparative Example 1 used a conventional negative electrode formulation (6DZF20).

[0064] Comparative Example 2: (Unmodified hydrogen inhibitor)

[0065] The difference between Comparative Example 2 and Example 1 is that bismuth oxide is used as the hydrogen inhibitor, and the hydrogen inhibitor is not hydrophobically modified. All other conditions are the same as in Example 1.

[0066] Comparative Example 3: (Complete hydrophobic modification of hydrogen inhibitor surface)

[0067] The difference between Comparative Example 3 and Example 1 is that the preparation step of the hydrophobic hydrogen inhibitor in step (2) is: bismuth oxide is completely immersed in the hydrophobic modifier and dried and cured, and the other conditions are the same as in Example 1.

[0068] Application examples

[0069] The negative electrode lead pastes from Examples 1-3 and Comparative Examples 1-3 were used to make battery negative electrodes, and then the negative electrodes were used to make lead-carbon batteries according to conventional methods.

[0070] Example of detection:

[0071] The lead-carbon batteries prepared with negative electrode lead paste from Examples 1-3 and Comparative Examples 1-3 were subjected to battery performance tests. The test indicators were: room temperature capacity, low temperature (-10℃) capacity, cycle life, and battery water loss after 300 cycles. The test results are shown in Table 1.

[0072] Table 1 Test Results

[0073] Capacity at room temperature / min (2hr) -10℃ low temperature capacity / min (2hr) Cycle life / times Water loss / g Example 1 138 108 471 42.12 Example 2 138 109 487 42.27 Example 3 139 109 502 40.94 Comparative Example 1 128 96 389 48.56 Comparative Example 2 130 102 407 45.19 Comparative Example 3 125 94 323 51.02

[0074] As shown in Table 1, compared with Comparative Example 1 (conventional lead-carbon battery), the lead-carbon batteries in Examples 1-3 all have higher room temperature and low temperature capacity, faster charging speed and longer cycle life, indicating that the lead-carbon battery negative electrode paste provided in this application can improve the performance of lead-acid batteries.

[0075] The hydrogen inhibitor in Comparative Example 2 was not modified. Compared with Comparative Example 1, the battery performance of Comparative Example 2 was improved to some extent, but not significantly. Compared with Comparative Example 2, the battery performance of Example 1 was significantly improved. This shows that although using the unmodified hydrogen inhibitor as a raw material to prepare negative electrode lead paste can improve the battery performance, the improvement effect is not significant. However, using the partially modified hydrogen inhibitor provided in this application can significantly improve the battery performance. Analyzing the water loss data of Example 1, Comparative Example 1, and Comparative Example 2 separately, it can be seen that the water loss of Example 1 is significantly lower than that of Comparative Example 1 and Comparative Example 2. This indicates that the partially modified hydrogen inhibitor provided in this application can significantly inhibit the water loss of the battery, and its effect is more significant than that of the unmodified hydrogen inhibitor.

[0076] The surface of the hydrogen inhibitor in Comparative Example 3 was completely modified. Data analysis showed that the battery performance of Comparative Example 3 was lower than that of Comparative Example 1 and Comparative Example 2. Furthermore, by comparing the water loss data, it was found that the water absorption of Comparative Example 3 was higher than that of Comparative Example 1. The reason for the above problems may be that after using a completely modified surface hydrogen inhibitor, the completely hydrophobic hydrogen inhibitor is completely encapsulated inside the emulsion particles of the additive. When the additive forms a cross-linked network, the completely hydrophobic hydrogen inhibitor is encapsulated inside the cross-linked network and cannot participate in the electrolyte reaction, thus failing to play a hydrogen inhibition role, which leads to an increase in water loss.

[0077] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A negative electrode paste for a lead-carbon battery, characterized in that, The raw materials, by weight, include: 360-410 parts β-lead oxide, 590-640 parts α-lead oxide powder, 3-5 parts mixed carbon, 10-15 parts barium sulfate, 1-3 parts humic acid, 1-3 parts sodium lignosulfonate, 0.5-1 part hydrophobic hydrogen inhibitor, 0.5 parts vanillin, 1-2 parts conductive fiber, 40-45 parts sulfuric acid, 5-10 parts additives, and the balance being pure water. The additives are tetrafluoroethylene-acrylic acid copolymers, and the mass ratio of the tetrafluoroethylene-acrylic acid copolymers is 3-4:

1. The hydrophobic hydrogen inhibitor includes bismuth oxide and a hydrophobic modifier. The hydrophobic hydrogen inhibitor is prepared by accelerating the bismuth oxide and passing it through droplets formed by the hydrophobic modifier, followed by curing.

2. The lead paste for the negative electrode of a lead-carbon battery according to claim 1, characterized in that, The mixed carbon includes one or more of activated carbon, carbon black, and graphene.

3. The lead paste for the negative electrode of a lead-carbon battery according to claim 1, characterized in that, The conductive fibers include polyurethane fibers and / or polyacrylonitrile fibers.

4. The lead paste for the negative electrode of a lead-carbon battery according to claim 1, characterized in that, The hydrophobic modifier includes one or more of trimethylchlorosilane, thiophenol, and 1,3-propanedithiol.

5. A method for preparing lead paste for the negative electrode of a lead-carbon battery according to any one of claims 1 to 4, characterized in that, Includes the following steps: (1) Add β-lead oxide and pure water to the reaction vessel and stir. After stirring, add sulfuric acid dropwise and heat to obtain initial lead paste. Vacuum dry the initial lead paste and grind it to make initial lead powder. (2) Add the additives and hydrophobic hydrogen inhibitors to pure water to make an emulsion; (3) Place the initial lead powder obtained in step (1) into a paste mixing machine and add α-lead oxide, mixed carbon, barium sulfate, humic acid, sodium lignin sulfonate, conductive fiber and vanillin in sequence and mix evenly. Then add the emulsion obtained in step (2) and stir evenly to obtain negative electrode lead paste.

6. A preparation method according to claim 5, characterized in that, The stirring time in step (1) is 5~15 min; the heating temperature is 50~70℃ and the heating time is 1~2 h; the vacuum drying temperature is 60~70℃ and the vacuum drying time is 3~5 h; the moisture content of the initial lead powder is less than 0.5% and the average particle size of the initial lead powder is 1~2 μm.

7. A storage battery, characterized in that, The negative electrode includes the negative electrode paste prepared by any one of claims 1 to 4 or the negative electrode paste prepared by any one of claims 5 to 6.

8. An electric vehicle, characterized in that, Includes the storage battery as described in claim 7.