Nested coated antimony carbon material as well as preparation method and application thereof

Abstract

The invention relates to a nested coated antimony carbon material as well as a preparation method and application thereof, and belongs to the technical field of lead-acid batteries. The nested coated antimony carbon material comprises graphite and an antimony carbon coating structure, the antimony-carbon coating structure comprises an antimony trioxide inner core and a carbon coating layer, and the antimony-carbon coating structure is embedded in graphite; in an X-ray diffraction pattern of the nested coated antimony carbon material, [C (222) + C (10-2)] / C (002) is equal to 0.1-1, and C (10-2) / C (222) is equal to 0.01-0.1; the mass content of antimony trioxide in the nested coated antimony carbon material is 30-90%. After the nested coated antimony carbon material is applied to a lead-acid battery positive electrode additive, a lead-acid battery positive electrode lead plaster and a lead-acid battery, the influence of an antimony-free effect can be avoided in the lead-acid battery formation and charge-discharge processes, the discharge capacity of the lead-acid battery is effectively improved, and the cycle life of the lead-acid battery is effectively prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lead-acid batteries, in particular to a nested coated antimony-carbon material and a preparation method and application thereof. BACKGROUND

[0002] The lead-acid battery is one of the most mature and widely used energy storage batteries at present. At present, the discharge capacity of the positive plate of the lead-acid battery is much lower than that of the negative plate. Therefore, improving the utilization rate of the positive active material (PAM) is the key to improving the energy density of the lead-acid battery.

[0003] In the prior art, the addition of positive additives of the lead-acid battery and the optimization of the positive paste formula of the lead-acid battery are used to try to solve the above technical problems. For example, Chinese patent CN107317027B uses four basic lead sulfate (4BS) crystals to improve the cycle life of the battery, but the problem of "antimony-free effect" in the corrosion layer of the grid interface still exists. To solve the problem of "antimony-free effect" in the positive paste of the lead-acid battery, the current technology is to directly add antimony trioxide during the mixing process. However, the direct addition of antimony trioxide will inhibit the generation of 4BS crystals in the positive paste of the lead-acid battery, and small-sized 3BS crystals are generated, which leads to a decrease in the porosity of the positive paste of the lead-acid battery, a low skeleton strength of the PAM, and a low cycle life of the lead-acid battery. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a nested coated antimony-carbon material and a preparation method and application thereof. The nested coated antimony-carbon material has an antimony-carbon coating structure, and the structure is embedded in graphite. The nested coated antimony-carbon material can be used as a positive additive of the lead-acid battery in combination with 4BS crystals for the positive paste of the lead-acid battery. Since the antimony trioxide core in the nested coated antimony-carbon material is coated in the carbon coating layer, the carbon coating layer can prevent the release of the antimony trioxide core during the mixing process of the positive paste of the lead-acid battery, reduce the inhibitory effect on the generation of 4BS crystals, increase the content of 4BS crystals in the positive paste of the lead-acid battery, and also help to increase the porosity of the positive paste of the lead-acid battery and enhance the skeleton structure strength of the positive paste of the lead-acid battery. When the positive paste of the lead-acid battery is coated on the positive plate and prepared into a lead-acid battery, the antimony trioxide core coated by the carbon coating layer is released during the formation process of the lead-acid battery, so that the lead-acid battery avoids the influence of "antimony-free effect" during the charging and discharging process, effectively improves the discharge capacity and cycle life of the lead-acid battery.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions: This invention provides a nested antimony-carbon material, comprising graphite and an antimony-carbon coating structure; the antimony-carbon coating structure comprises an antimony trioxide core and a carbon coating layer, the antimony-carbon coating structure being embedded in the graphite; in the X-ray diffraction pattern of the nested antimony-carbon material, the peak intensity C of the characteristic peak of the (222) crystal plane is... (222) The peak intensity C of the characteristic peak of the (10-2) crystal plane (10-2) The sum of the peak intensities of the characteristic peaks of the (002) crystal plane and C (002) The ratio [C] (222) + C (10-2) ] / C (002) =0.1~1, and the peak intensity C of the characteristic peak of the (10-2) crystal plane is... (10-2) The peak intensity C of the characteristic peak of the (222) crystal plane (222) The ratio of C (10-2) / C (222) =0.01~0.1; The mass content of antimony trioxide in the nested antimony-carbon material is 30~90%. Among them, the characteristic peak of the (222) crystal plane corresponds to the characteristic peak of antimony trioxide, the characteristic peak of the (10-2) crystal plane corresponds to the characteristic peak of antimony element, and the characteristic peak of the (002) crystal plane corresponds to the characteristic peak of graphite.

[0006] [C (222) + C (10-2) ] / C (002) The ratio can specifically be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0, or other values ​​within the range of 0.1 to 1.0; C (10-2) / C (222) The ratio can specifically be 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1 or other values ​​in the range of 0.01 to 0.1; the mass content of antimony trioxide in the nested antimony-carbon material can specifically be 30%, 40%, 50%, 60%, 70%, 80%, 90% or other values ​​in the range of 30% to 90%.

[0007] Preferably, in the X-ray diffraction pattern of the nested antimony-carbon material, the peak intensity C of the characteristic peak of the (222) crystal plane is... (222) The peak intensity C of the characteristic peak of the (10-2) crystal plane (10-2) The sum of the peak intensities of the characteristic peaks of the (002) crystal plane and C (002) The ratio [C] (222) + C (10-2) ] / C (002) =0.2~0.8, and the peak intensity C of the characteristic peak of the (10-2) crystal plane is... (10-2) The peak intensity C of the characteristic peak of the (222) crystal plane (222)The ratio of C (10-2) / C (222) =0.02~0.1; the antimony trioxide content in the nested coated antimony-carbon material is 30-80% by mass. More preferably, [C (222) + C (10-2) ] / C (002) =0.5~0.8; C (10-2) / C (222) =0.03~0.1; the mass content of antimony trioxide in the nested antimony-carbon material is 40-80%.

[0008] The present invention also provides a method for preparing any of the above-described nested antimony-carbon materials, comprising the following steps: S1: Graphite, antimony trioxide and organic carbon source are thoroughly mixed to obtain a mixture; wherein the mass ratio of graphite, antimony trioxide and organic carbon source is (10~80): (10~80): (5~20); S2: The mixture is first calcined at 200-400°C for 2-4 hours under an inert atmosphere or vacuum to melt the organic carbon source and coat it onto the surface of antimony trioxide; then the temperature is raised to 400-600°C and calcined for 3-12 hours to carbonize the organic carbon source and form the carbon coating layer, thus obtaining the sintered material; S3: Cool and crush the sintered material to obtain the nested coated antimony-carbon material.

[0009] Preferably, the organic carbon source is at least one of glucose, asphalt, petroleum coke, lignin, and polyethylene glycol; more preferably, the organic carbon source is asphalt.

[0010] Preferably, the mass ratio of graphite, antimony trioxide, and organic carbon source in the original mixture is (30-60):(35-65):(5-15). More preferably, the mass ratio of graphite, antimony trioxide, and organic carbon source in the original mixture is (40-60):(35-50):(5-15).

[0011] Preferably, in step S2, the material is first calcined at 300-400°C for 2-3 hours, and then calcined at 500-600°C for 5-10 hours.

[0012] The present invention discloses a method for preparing a nested antimony-carbon material, which involves calcining a mixture in an inert atmosphere or vacuum in two steps. First, the mixture is calcined at 300-400°C for 2-3 hours to melt the organic carbon source and coat it onto the surface of antimony trioxide. Then, it is held at 500-600°C for 5-10 hours to carbonize the organic carbon source and form the carbon coating layer. By controlling the temperature and time of the two calcinations, the invention forms a nested antimony-carbon material with a specific structure, ensuring that the core of the antimony-carbon coating structure is primarily antimony trioxide. Simultaneously, the graphite material serves as a substrate, allowing the antimony-carbon coating structure to be nested on the graphite surface. During the formation of lead-acid batteries, the conductivity of the graphite substrate enables the rapid release of the antimony trioxide core coated by the carbon coating layer. This specific microstructure is key to achieving the "time-controlled release" function of antimony trioxide. When the nested antimony-carbon material is combined with 4BS seed crystals as a positive electrode additive for lead-acid batteries and used in the positive electrode paste of lead-acid batteries, the carbon coating layer can effectively isolate antimony trioxide in the paste and curing environment, preventing antimony ions from dissolving and inhibiting the growth of 4BS crystals. When the positive electrode paste of lead-acid batteries is coated on the positive electrode plate and a lead-acid battery is prepared, in the acidic environment of lead-acid battery formation and subsequent charging and discharging, the electrolyte can gradually penetrate the carbon layer, causing antimony ions to dissolve and be slowly released, migrating to the grid interface, thereby eliminating the "antimony-free effect". The present invention also provides an application of any of the above-described nested antimony-carbon materials in lead-acid battery cathode additives.

[0013] As a preferred embodiment of the present invention, the present invention provides a lead-acid battery cathode additive comprising 4BS seed crystals and any of the nested antimony-carbon materials described above, wherein the mass ratio of the nested antimony-carbon material to the 4BS seed crystals is (0.1~0.5):1.

[0014] This invention also provides a lead-acid battery positive electrode paste, comprising lead powder, water, sulfuric acid solution, and the aforementioned lead-acid battery positive electrode additive. Based on 100% lead powder, the amount of the lead-acid battery positive electrode additive is 1-2 wt%, the amount of water is 9-13 wt%, and the density of the sulfuric acid solution is 1.40 g / cm³. 3 The dosage is 8-12 wt%.

[0015] Preferably, the lead-acid battery positive electrode paste further includes 0.1-0.5 wt% stannous sulfate, 0.1-0.2 wt% short fibers, and 2-8 wt% red lead.

[0016] This invention also provides a method for preparing lead paste for the positive electrode of a lead-acid battery, comprising the following steps: T1: Add lead powder, positive electrode additive, stannous sulfate, short fiber and red lead to a paste mixer and perform dry mixing to obtain a dry powder mixture. The dry mixing time is 3 to 10 minutes. T2: Add water and sulfuric acid to the dry powder mixture and perform wet mixing to obtain lead paste intermediate. The wet mixing time is 10~30min. T3: Stir the lead paste intermediate to obtain lead-acid battery positive electrode lead paste.

[0017] The present invention also provides a lead-acid battery, comprising a positive electrode plate, a negative electrode plate, a separator, and an electrolyte, wherein the positive electrode plate is obtained by the above-mentioned lead-acid battery positive electrode lead paste through a coating, curing, and formation process.

[0018] Beneficial technical effects of the present invention: The nested antimony-carbon material of the present invention has an antimony-carbon coating structure, which is embedded in graphite. The present invention forms a nested antimony-carbon material through coating technology, and uses the nested antimony-carbon material in combination with 4BS seed crystals as a positive electrode additive for lead-acid batteries in lead-acid battery positive electrode paste. Since the antimony trioxide core in the nested antimony-carbon material is coated within the carbon coating layer, it effectively isolates the contact between antimony trioxide and the lead paste system in the paste and curing environment, avoiding its inhibitory effect on the growth of 4BS crystals, and ensuring the successful construction of a large and robust 4BS framework.

[0019] This invention defines the peak intensity C of the characteristic peak of the (10-2) crystal plane. (10-2) The peak intensity C of the characteristic peak of the (222) crystal plane (222) The ratio of C (10-2) / C (222) =0.01~0.1, so that the nested coated antimony-carbon material can exert the antimony effect in subsequent applications; the main substance exerting the antimony effect is antimony trioxide. In the preparation process of the nested coated antimony-carbon material of the present invention, the carbon coating layer is used to coat antimony trioxide as much as possible to reduce the possibility of antimony trioxide being reduced to elemental antimony. Therefore, the nested coated antimony-carbon material of the present invention is limited to C (10-2) / C (222) The smaller the ratio, the better the nested antimony-carbon material can exert its antimony effect in subsequent applications.

[0020] When the lead paste for the positive electrode of the lead-acid battery is coated onto the positive electrode plate and a lead-acid battery is prepared, during the subsequent battery formation and charge / discharge process, the electrolyte (sulfuric acid) gradually penetrates the pores or defects of the carbon layer, allowing antimony ions to dissolve and be released gradually. These antimony ions migrate to the grid interface during formation, effectively solving the "antimony-free effect" problem. Due to the combination of an excellent 4BS framework structure and good grid interface characteristics, the lead-acid battery prepared by this invention possesses both a positive electrode active material with high porosity and high framework strength, and a grid interface with low impedance, thereby significantly improving the battery's deep cycle life and discharge capacity. Attached Figure Description

[0021] Figure 1 The image shows the XRD pattern of the nested antimony-carbon material prepared in Example 1 of this invention. Figure 2 This is a SEM image of the nested antimony-carbon material prepared in Example 1 of the present invention; Figure 3 This is a SEM image of the lead paste for the positive electrode of a lead-acid battery prepared in Example 1 of the present invention; Figure 4 SEM image of the lead paste for the positive electrode of the lead-acid battery prepared for Comparative Example 1. Detailed Implementation

[0022] The technical solutions of the embodiments 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, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1 This embodiment provides a nested antimony-carbon material, including graphite and an antimony-carbon coating structure; the antimony-carbon coating structure includes an antimony trioxide core and a carbon coating layer, and the antimony-carbon coating structure is embedded in the graphite.

[0024] The preparation method of the nested antimony-carbon material in this embodiment includes the following steps: S1: Graphite, antimony trioxide, and asphalt are thoroughly mixed in a plow mixer at a mass ratio of 40:50:10 to obtain a mixture. S2: The above mixture is fed into a rotary kiln for calcination at 300°C for 3 hours to melt the asphalt and coat the surface of antimony trioxide; then the temperature is raised to 550°C for calcination for 5 hours to carbonize the asphalt and form a carbon coating layer to obtain sintered material. S3: Then, the above sintered material is cooled to room temperature, and the sintered material is crushed to obtain powder material, which is the nested coated antimony carbon material of this embodiment.

[0025] Please see Figure 1 and Figure 2 , Figure 1 and 2 The images shown are the XRD and SEM images of the nested antimony-carbon material in this embodiment. Figure 1 C (222) =8445; C (10-2) =621; C (002) =14695; [C (222) + C (10-2)] / C (002) =0.62; C (10-2) / C (222) =0.07; The mass content of antimony trioxide in the nested antimony-carbon material of this embodiment is 48%. Figure 2 As can be seen, in nested antimony-carbon materials, there are many antimony-carbon coating structures embedded in graphite. The antimony-carbon coating structure includes an antimony trioxide core and a carbon coating layer.

[0026] This embodiment also provides a lead-acid battery positive electrode additive, comprising the nested antimony-carbon material and 4BS seed crystals of this embodiment, wherein the mass ratio of the nested antimony-carbon material to the 4BS seed crystals is 0.2:1. The nested antimony-carbon material and 4BS seed crystals prepared in this embodiment are mixed in a specific ratio to obtain the lead-acid battery positive electrode additive of this embodiment.

[0027] This embodiment also provides a lead-acid battery positive electrode paste, comprising lead powder, the aforementioned lead-acid battery positive electrode additive, water, sulfuric acid, stannous sulfate, red lead, and short fibers. Based on 100% lead powder by weight, the amount of lead-acid battery positive electrode additive is 1 wt%, the amount of water is 12 wt%, and the sulfuric acid solution (density 1.40 g / cm³) is also included. 3 The dosage is 10wt%, stannous sulfate is 0.1wt%, red lead is 3wt%, and short fiber is 0.1wt%.

[0028] The method for preparing lead paste for the positive electrode of a lead-acid battery in this embodiment includes the following steps: T1: Add lead powder, the above-mentioned lead-acid battery positive electrode additive, stannous sulfate, red lead, and short fiber to the paste mixer, and perform dry mixing for 8 minutes to obtain dry powder mixture. T2: Add water and sulfuric acid to the dry powder mixture and perform wet mixing for 20 minutes to obtain lead paste intermediate; T3: Stir the lead paste intermediate to obtain lead-acid battery positive electrode lead paste.

[0029] Please see Figure 3 , Figure 3 The image shows an SEM image of the lead-acid battery positive electrode paste prepared in this embodiment. It can be seen from the image that after adding the lead-acid battery positive electrode additive of this embodiment, the crystal form in the lead-acid battery positive electrode paste is rod-shaped 4BS crystals.

[0030] This embodiment also provides a lead-acid battery, including a positive electrode plate, a negative electrode plate, a separator, and an electrolyte; wherein, the positive electrode plate is obtained by coating, curing, and forming a lead-acid battery positive electrode paste according to this embodiment. In this embodiment, the lead-acid battery positive electrode paste of this embodiment is coated and cured to obtain a positive electrode plate coated with the lead-acid battery positive electrode paste of this embodiment, and a 12V20Ah lead-acid battery is manufactured according to conventional processes.

[0031] Example 2 This embodiment provides a nested antimony-carbon material, including graphite and an antimony-carbon coating structure; the antimony-carbon coating structure includes an antimony trioxide core and a carbon coating layer, and the antimony-carbon coating structure is embedded in the graphite.

[0032] The preparation method of the nested antimony-carbon material in this embodiment includes the following steps: S1: Graphite, antimony trioxide, and asphalt are thoroughly mixed in a plow mixer at a mass ratio of 60:35:5 to obtain a mixture. S2: The above mixture is fed into a rotary kiln for calcination at 400°C for 2 hours to melt the asphalt and coat the surface of antimony trioxide; then the temperature is raised to 500°C for calcination for 10 hours to carbonize the asphalt and form a carbon coating layer to obtain sintered material. S3: Then, the above sintered material is cooled to room temperature, and the sintered material is crushed to obtain powder material, which is the nested coated antimony carbon material of this embodiment.

[0033] In the XRD test results of the nested antimony-carbon material in this embodiment, C (222) =4451;C (10-2) =84;C (002) =21843; [C (222) + C (10-2) ] / C (002) =0.21; C (10-2) / C (222) =0.02; The mass content of antimony trioxide in the nested antimony-carbon material of this embodiment is 33%.

[0034] This embodiment also provides a lead-acid battery positive electrode additive, comprising the nested antimony-carbon material and 4BS seed crystals of this embodiment, wherein the mass ratio of the nested antimony-carbon material to the 4BS seed crystals is 0.3:1. The nested antimony-carbon material and 4BS seed crystals prepared in this embodiment are mixed in a specific ratio to obtain the lead-acid battery positive electrode additive of this embodiment.

[0035] This embodiment also provides a lead-acid battery positive electrode paste, comprising lead powder, the aforementioned lead-acid battery positive electrode additive, water, sulfuric acid, stannous sulfate, red lead, and short fibers. Based on 100% lead powder, the amount of lead-acid battery positive electrode additive is 1.5 wt%, the amount of water is 12 wt%, and the sulfuric acid solution (density 1.40 g / cm³) is... 3 The dosage is 10wt%, stannous sulfate is 0.1wt%, red lead is 3wt%, and short fiber is 0.1wt%.

[0036] The method for preparing lead paste for the positive electrode of a lead-acid battery in this embodiment includes the following steps: T1: Add lead powder, the above-mentioned lead-acid battery positive electrode additive, stannous sulfate, red lead, and short fiber to the paste mixer, and perform dry mixing for 8 minutes to obtain dry powder mixture. T2: Add water and sulfuric acid to the dry powder mixture and perform wet mixing for 20 minutes to obtain lead paste intermediate; T3: Stir the lead paste intermediate to obtain lead-acid battery positive electrode lead paste.

[0037] This embodiment also provides a lead-acid battery, including a positive electrode plate, a negative electrode plate, a separator, and an electrolyte; wherein, the positive electrode plate is obtained by coating, curing, and forming a lead-acid battery positive electrode paste according to this embodiment. In this embodiment, the lead-acid battery positive electrode paste of this embodiment is coated and cured to obtain a positive electrode plate coated with the lead-acid battery positive electrode paste of this embodiment, and a 12V20Ah lead-acid battery is manufactured according to conventional processes.

[0038] Example 3 This embodiment provides a nested antimony-carbon material, including graphite and an antimony-carbon coating structure; the antimony-carbon coating structure includes an antimony trioxide core and a carbon coating layer, and the antimony-carbon coating structure is embedded in the graphite.

[0039] The preparation method of the nested antimony-carbon material in this embodiment includes the following steps: S1: Graphite, antimony trioxide, and asphalt are thoroughly mixed in a plow mixer at a mass ratio of 50:40:10 to obtain a mixture. S2: The above mixture is fed into a rotary kiln for calcination at 300°C for 3 hours to melt the asphalt and coat the surface of antimony trioxide; then the temperature is raised to 600°C for calcination for 6 hours to carbonize the asphalt and form a carbon coating layer to obtain sintered material. S3: Then, the above sintered material is cooled to room temperature, and the sintered material is crushed to obtain powder material, which is the nested coated antimony carbon material of this embodiment.

[0040] In the XRD test results of the nested antimony-carbon material in this embodiment, C (222) =7136;C (10-2) =437;C (002) =16246; [C (222) + C (10-2) ] / C (002) =0.47; C (10-2) / C (222) =0.06, the mass content of antimony trioxide in the nested antimony-carbon material of this embodiment is 38%.

[0041] This embodiment also provides a lead-acid battery cathode additive, comprising the nested antimony-carbon material and 4BS seed crystals of this embodiment, wherein the mass ratio of the nested antimony-carbon material to the 4BS seed crystals is 0.25:1. The antimony-carbon nested structure material and the 4BS seed crystals of this embodiment are mixed in a specific ratio to obtain the lead-acid battery cathode additive of this embodiment.

[0042] This embodiment also provides a lead-acid battery positive electrode paste, comprising lead powder, the aforementioned lead-acid battery positive electrode additive, water, sulfuric acid, stannous sulfate, short fibers, and red lead. Based on 100% lead powder, the amount of lead-acid battery positive electrode additive is 1.5 wt%, the amount of water is 12 wt%, and the sulfuric acid solution (density 1.40 g / cm³) is... 3 The dosage is 10wt%, stannous sulfate is 0.1wt%, red lead is 3wt%, and short fiber is 0.1wt%.

[0043] The method for preparing lead paste for the positive electrode of a lead-acid battery in this embodiment includes the following steps: T1: Add lead powder, the above-mentioned lead-acid battery positive electrode additive, stannous sulfate, red lead, and short fiber to the paste mixer, and perform dry mixing for 8 minutes to obtain dry powder mixture. T2: Add water and sulfuric acid to the dry powder mixture and perform wet mixing for 20 minutes to obtain lead paste intermediate; T3: Stir the lead paste intermediate to obtain lead-acid battery positive electrode lead paste.

[0044] This embodiment also provides a lead-acid battery, including a positive electrode plate, a negative electrode plate, a separator, and an electrolyte; wherein, the positive electrode plate is obtained by coating, curing, and forming a lead-acid battery positive electrode paste according to this embodiment. In this embodiment, the lead-acid battery positive electrode paste of this embodiment is coated and cured to obtain a positive electrode plate coated with the lead-acid battery positive electrode paste of this embodiment, and a 12V20Ah lead-acid battery is manufactured according to conventional processes.

[0045] Example 4 This embodiment provides a nested antimony-carbon material, including graphite and an antimony-carbon coating structure; the antimony-carbon coating structure includes an antimony trioxide core and a carbon coating layer, and the antimony-carbon coating structure is embedded in the graphite.

[0046] The preparation method of the nested antimony-carbon material in this embodiment includes the following steps: S1: Graphite, antimony trioxide, and asphalt are thoroughly mixed in a plow mixer at a mass ratio of 40:45:15 to obtain a mixture. S2: The above mixture is fed into a rotary kiln for calcination at 350°C for 2 hours to melt the asphalt and coat the surface of antimony trioxide; then the temperature is raised to 550°C for calcination for 8 hours to carbonize the asphalt and form a carbon coating layer to obtain sintered material. S3: Then, the above sintered material is cooled to room temperature, and the sintered material is crushed to obtain powder material, which is the nested coated antimony carbon material of this embodiment.

[0047] In the XRD test results of the nested antimony-carbon material in this embodiment, C (222) =7819;C (10-2) =783;C (002) =13769; [C (222) + C (10-2) ] / C (002) =0.62; C (10-2) / C (222) =0.1; The mass content of antimony trioxide in the nested antimony-carbon material of this embodiment is 42%.

[0048] This embodiment also provides a positive electrode additive comprising the nested coated antimony-carbon material prepared in this embodiment and 4BS seed crystals, wherein the mass ratio of the nested coated antimony-carbon material to the 4BS seed crystals is 0.2:1. The nested coated antimony-carbon material and 4BS seed crystals prepared in this embodiment are mixed in a specific ratio to obtain the lead-acid battery positive electrode additive of this embodiment.

[0049] This embodiment also provides a lead-acid battery positive electrode paste, comprising lead powder, the aforementioned lead-acid battery positive electrode additive, water, sulfuric acid, stannous sulfate, short fibers, and red lead. Based on 100% lead powder, the amount of lead-acid battery positive electrode additive is 1.5 wt%, the amount of water is 12 wt%, and the sulfuric acid solution (density 1.40 g / cm³) is... 3 The dosage is 10wt%, stannous sulfate is 0.1wt%, red lead is 3wt%, and short fiber is 0.1wt%.

[0050] The method for preparing lead paste for the positive electrode of a lead-acid battery in this embodiment includes the following steps: T1: Add lead powder, the above-mentioned lead-acid battery positive electrode additive, stannous sulfate, red lead, and short fiber to the paste mixer, and perform dry mixing for 8 minutes to obtain dry powder mixture. T2: Add water and sulfuric acid to the dry powder mixture and perform wet mixing for 20 minutes to obtain lead paste intermediate; T3: Stir the lead paste intermediate to obtain lead-acid battery positive electrode lead paste.

[0051] This embodiment also provides a lead-acid battery, including a positive electrode plate, a negative electrode plate, a separator, and an electrolyte; wherein, the positive electrode plate is obtained by coating, curing, and forming a lead-acid battery positive electrode paste according to this embodiment. In this embodiment, the lead-acid battery positive electrode paste of this embodiment is coated and cured to obtain a positive electrode plate coated with the lead-acid battery positive electrode paste of this embodiment, and a 12V20Ah lead-acid battery is manufactured according to conventional processes.

[0052] Comparative Example 1 This comparative example directly uses the same mass of antimony trioxide instead of the nested antimony-carbon material in Example 1; all other aspects are the same as in Example 1. That is: This comparative example provides a lead-acid battery positive electrode additive comprising antimony trioxide and 4BS seed crystals, with a mass ratio of antimony trioxide to 4BS seed crystals of 0.2:1. Antimony trioxide and 4BS seed crystals are mixed in the specified ratio to obtain the lead-acid battery positive electrode additive of this comparative example.

[0053] This comparative example also provides a lead-acid battery positive electrode paste, comprising lead powder, the aforementioned lead-acid battery positive electrode additive, water, sulfuric acid, stannous sulfate, short fibers, and red lead. Based on 100% lead powder by weight, the amount of lead-acid battery positive electrode additive is 1.5 wt%, the amount of water is 12 wt%, and the sulfuric acid solution (density 1.40 g / cm³) is... 3 The dosage is 10wt%, stannous sulfate is 0.1wt%, red lead is 3wt%, and short fiber is 0.1wt%.

[0054] The preparation method of the positive electrode paste for lead-acid batteries in this comparative example includes the following steps: T1: Add lead powder, the above positive electrode additive, stannous sulfate, red lead, and short fiber to the paste mixer, and perform dry mixing for 8 minutes to obtain a dry powder mixture. T2: Add water and sulfuric acid to the dry powder mixture and perform wet mixing for 20 minutes to obtain lead paste intermediate; T3: Stir the lead paste intermediate to obtain lead-acid battery positive electrode lead paste.

[0055] Please see Figure 4 , Figure 4 The image shows the SEM image of the positive electrode paste for the lead-acid battery formed in this comparative example. It can be seen from the image that the crystals in the positive electrode paste for the lead-acid battery in this comparative example are 3BS crystals. That is, the formation of 4BS crystals was suppressed by directly mixing antimony trioxide with 4BS seed crystals, and 3BS crystals with smaller crystal size were generated.

[0056] This comparative example also provides a lead-acid battery, including a positive electrode plate, a negative electrode plate, a separator, and an electrolyte; wherein the positive electrode plate is prepared by coating, curing, and forming the positive electrode paste of the lead-acid battery of this embodiment. In this comparative example, the positive electrode paste of the lead-acid battery of this comparative example is coated and cured to obtain a positive electrode plate coated with the positive electrode paste of the lead-acid battery of this embodiment, and a 12V20Ah lead-acid battery is manufactured according to conventional processes.

[0057] Performance testing The lead-acid batteries obtained in Examples 1-4 and Comparative Example 1 were subjected to cyclic charge-discharge tests under the following conditions: ① constant voltage 14.8V, current 10A for 4.5h, ② then discharged at 10A to the termination voltage of 10.5V, ③ repeating steps ① to ② constitutes one cycle. The battery cycle test results are shown in Table 1.

[0058] Table 1. Capacity and cycle test results of lead-acid batteries in Examples 1-4 and Comparative Example 1

[0059] According to the results in Table 1, all of Examples 1-4 used the nested antimony-carbon material prepared in this invention as an additive to finally form lead-acid batteries. Compared with the lead-acid battery formed by directly adding antimony trioxide as an additive without coating in Comparative Example 1, the capacity and cycle number were improved, which effectively brought into play the dual effects of antimony effect and 4BS crystal.

[0060] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and the present invention also intends to include these modifications and variations.

Claims

1. A nested, coated antimony-carbon material, characterized in that, The structure includes graphite and antimony-carbon coating; the antimony-carbon coating structure includes an antimony trioxide core and a carbon coating layer, and the antimony-carbon coating structure is embedded in the graphite; in the X-ray diffraction pattern of the nested antimony-carbon material, the peak intensity C of the characteristic peak of the (222) crystal plane is... (222) The peak intensity C of the characteristic peak of the (10-2) crystal plane (10-2) The sum of the peak intensities of the characteristic peaks of the (002) crystal plane and C (002) The ratio [C] (222) + C (10-2) ] / C (002) =0.1~1, and the peak intensity C of the characteristic peak of the (10-2) crystal plane is... (10-2) The peak intensity C of the characteristic peak of the (222) crystal plane (222) The ratio of C (10-2) / C (222) =0.01~0.1; the mass content of antimony trioxide in the nested antimony-carbon material is 30~90%.

2. The nested antimony-carbon material according to claim 1, characterized in that, In the X-ray diffraction pattern of the nested antimony-carbon material, the peak intensity C of the characteristic peak of the (222) crystal plane is... (222) The peak intensity C of the characteristic peak of the (10-2) crystal plane (10-2) The sum of the peak intensities of the characteristic peaks of the (002) crystal plane and C (002) The ratio [C] (222) + C (10-2) ] / C (002) =0.2~0.8, and the peak intensity C of the characteristic peak of the (10-2) crystal plane is... (10-2) The peak intensity C of the characteristic peak of the (222) crystal plane (222) The ratio of C (10-2) / C (222) =0.02~0.1; the mass content of antimony trioxide in the nested antimony-carbon material is 30-80%.

3. A method for preparing a nested, coated antimony-carbon material as described in any one of claims 1 to 2, characterized in that, Includes the following steps: S1: Graphite, antimony trioxide and organic carbon source are thoroughly mixed to obtain a mixture; wherein the mass ratio of graphite, antimony trioxide and organic carbon source is (10~80): (10~80): (5~20); S2: The mixture is first calcined at 200-400°C for 2-4 hours under an inert atmosphere or vacuum to melt the organic carbon source and coat it onto the surface of antimony trioxide; then the temperature is raised to 400-600°C and calcined for 3-12 hours to carbonize the organic carbon source and form the carbon coating layer, thus obtaining the sintered material; S3: Cool and crush the sintered material to obtain the nested coated antimony-carbon material.

4. The method for preparing the nested coated antimony-carbon material according to claim 3, characterized in that, The organic carbon source is at least one of glucose, asphalt, petroleum coke, lignin, and polyethylene glycol, and the mass ratio of graphite, antimony trioxide and organic carbon source in the mixture is (30-60):(35-65):(5-15).

5. The method for preparing the nested coated antimony-carbon material according to claim 4, characterized in that, The organic carbon source is asphalt. In step S2, it is first calcined at 300-400℃ for 2-3 hours, and then calcined at 500-600℃ for 5-10 hours.

6. A lead-acid battery positive electrode additive, characterized in that, It includes 4BS seed crystals and the nested coated antimony-carbon material as described in any one of claims 1 to 2, wherein the mass ratio of the nested coated antimony-carbon material to the 4BS seed crystals is (0.1 to 0.5):

1.

7. A lead-acid battery positive electrode paste, comprising lead powder, water, sulfuric acid solution, and the lead-acid battery positive electrode additive as described in claim 6, characterized in that... Based on 100% lead powder, the amount of the lead-acid battery positive electrode additive is 1-2 wt%, the amount of water is 9-13 wt%, and the density of the sulfuric acid solution is 1.40 g / cm³. 3 The dosage is 8-12 wt%.

8. The lead paste for the positive electrode of a lead-acid battery according to claim 7, characterized in that, The lead-acid battery positive electrode paste also includes 0.1-0.5 wt% stannous sulfate, 0.1-0.2 wt% short fibers, and 2-8 wt% red lead.

9. A method for preparing lead paste for a lead-acid battery positive electrode as described in claim 8, characterized in that, Includes the following steps: T1: Add lead powder, the lead-acid battery positive electrode additive, stannous sulfate, short fiber, and red lead to the paste mixer, and perform dry mixing to obtain a dry powder mixture. The dry mixing time is 3-10 minutes. T2: Add water and sulfuric acid to the dry powder mixture and perform wet mixing to obtain lead paste intermediate. The wet mixing time is 10~30min. T3: Stir the lead paste intermediate to obtain lead-acid battery positive electrode lead paste.

10. A lead-acid battery, comprising a positive electrode plate, a negative electrode plate, a separator, and an electrolyte, characterized in that, The positive electrode plate is prepared by coating, curing and formation processes of the lead-acid battery positive electrode paste as described in claim 7 or 8.

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