Active substance modification method, bipolar plate, lead-based battery and energy storage device

Abstract

The invention relates to an active substance modification method, a bipolar plate, a lead-based battery and an energy storage device. The active substance modification method comprises the following steps: mixing a raw material to be modified with modified graphite powder to form a mixture, and adding a plurality of impact balls; a high-speed stirring device is used for stirring the mixture, and under the high-energy impact of the impact balls, particles of the lead sulfate generate cracks and molecular lattices generate lattice distortion, so that fine particles of the graphene can enter the particle cracks and the molecular lattices of the lead sulfate. As fine particles of graphene exist in particle cracks and molecular lattices of the modified lead sulfate, the modified lead sulfate has good conductivity and continuously keeps good conductivity during charging and discharging, good conductivity and excellent activity can be ensured even if the proportion of the lead sulfate in a positive active material or the positive active material is 100%, and the positive active material can be applied to the field of lithium ion batteries. The specific capacity and the specific power of the lead-based battery are greatly improved, irreversible sulfation of a polar plate is prevented, and the service life is prolonged.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a method for modifying active materials, bipolar plates, lead-based batteries, and energy storage devices. Background Technology

[0002] Traditional lead-based batteries primarily use lead powder and lead oxide powder as their active materials. During charging, the lead powder in the positive electrode transforms into lead oxide under oxidation, while the negative electrode transforms into elemental lead powder under reduction. During discharging, the active materials in both the positive and negative electrodes gradually transform into lead sulfate powder. When the proportion of non-conductive lead sulfate powder in the positive and negative active materials exceeds 50%, the current conduction function between lead powder or lead oxide powder is disrupted. Furthermore, after multiple charge-discharge cycles, some lead sulfate powder in the active materials of traditional lead-based batteries agglomerates into non-conductive clumps. Therefore, the utilization rate of active materials in lead-based batteries is generally below 50%, resulting in generally poor specific capacity and specific power of lead-based batteries. Summary of the Invention

[0003] Therefore, it is necessary to provide an active material modification method, bipolar plate, lead-based battery and energy storage device to address the problem that the utilization rate of active materials in existing lead-based batteries is generally less than 50%, resulting in poor specific capacity and specific power of lead-based batteries.

[0004] A method for modifying an active substance, characterized by comprising the following steps:

[0005] The raw material to be modified is mixed with graphene-containing nano-graphite powder to form a mixture, and several impact balls are added; wherein the raw material to be modified contains lead sulfate powder;

[0006] The mixture is stirred using a high-speed stirring device, thereby causing cracks in the particle structure of lead sulfate and lattice distortion in the molecular crystal under the high kinetic energy impact of the impacting ball. This allows graphene microparticles to enter the interior of the lead sulfate particles, and some graphene microparticles to penetrate into the molecular crystal lattice of lead sulfate.

[0007] In one embodiment, the raw material to be modified further comprises lead powder;

[0008] The step of mixing the raw material to be modified with graphene-containing nano-graphite powder to form a mixture further includes:

[0009] A sulfuric acid diluent is added to the mixture, the temperature of which is between 60°C and 80°C.

[0010] In one embodiment, after the step of stirring the mixture using a high-speed stirring device, the method further includes:

[0011] The mixture is rapidly cooled, causing the lead sulfate dissolved in the solution to precipitate out as fine crystals.

[0012] In one embodiment, the impact ball is a zirconium ball.

[0013] In one embodiment, the high-speed stirring device rotates at a speed greater than or equal to 3000 rpm.

[0014] In one embodiment, the concentration of the sulfuric acid diluent is between 10% and 50%.

[0015] In one embodiment, the weight ratio of lead sulfate in the mixture to the graphene-containing nano-graphite powder is between 100:1 and 100:10.

[0016] A bipolar electrode plate includes a substrate, a positive current collector, a negative current collector, a positive active material layer, and a negative active material layer. The positive current collector and the negative current collector are respectively stacked on opposite sides of the substrate. The positive active material layer is stacked on the side of the positive current collector away from the substrate, and the negative active material layer is stacked on the side of the negative current collector away from the substrate.

[0017] Both the negative electrode active material layer and the positive electrode active material layer include the modified material prepared according to the active material modification method described in any of the above embodiments.

[0018] A lead-based battery includes a plurality of bipolar plates as described in any of the above embodiments, wherein the plurality of bipolar plates are stacked.

[0019] An energy storage device includes a lead-based battery as described in any of the above embodiments.

[0020] The above-mentioned active material modification method, bipolar plate, lead-based battery and energy storage device utilize a high-speed stirring device to stir the mixture, so that the impact ball impacts the lead sulfate particles and lead sulfate molecules with high energy, causing cracks in the lead sulfate particles and lattice distortion of the molecular crystal lattice. This allows the fine graphene particles to enter the cracks in the lead sulfate particles and the molecular crystal lattice more easily, thus achieving the modification of the raw material to be modified. The modified material exhibits excellent electrical conductivity due to the presence of fine graphene particles within the particle cracks of lead sulfate and its molecular lattice. Therefore, when used as the positive and / or negative active material in lead-based battery plates, it maintains excellent conductivity throughout the charging and discharging process. Even when the positive active material or the proportion of lead sulfate in the positive active material is 100%, it ensures excellent conductivity and activity, thus significantly improving the specific capacity and specific power of lead-based batteries. Furthermore, it prevents the formation of non-conductive interfaces and agglomerates on the surface and inside the positive and / or negative active materials of the plates, greatly extending the lifespan of lead-based batteries. Attached Figure Description

[0021] Figure 1 This is a flowchart of the steps of an active substance modification method in one embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of an active substance modification device according to an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of a lead-based battery in one embodiment of the present invention. Detailed Implementation

[0024] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0025] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0027] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0028] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0029] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0030] Please see Figure 1 and Figure 2 , Figure 1 A flowchart of an active substance modification method according to an embodiment of the present invention is shown. Figure 2 A schematic diagram of an active substance modification device is shown. An embodiment of the present invention provides a method for modifying active substances, comprising the following steps:

[0031] S10: The raw material to be modified is mixed with nano-graphite powder containing graphene to form a mixture 100, and a number of impact balls 200 are added; wherein, the raw material to be modified contains lead sulfate powder;

[0032] S20: The mixture 100 is stirred using a high-speed stirring device 400, causing cracks to form in the lead sulfate particles and lattice distortion in the molecular crystal under the high-energy impact of the impact ball 200. Because of the cracks in the lead sulfate particles and the lattice distortion, graphene microparticles can more easily enter the cracks and lattice of the lead sulfate particles, thus forming the modified material.

[0033] Thus, by using a high-speed stirring device 400 to stir the mixture 100, the impacting ball 200 delivers high-energy impacts to the lead sulfate molecules, causing cracks in the lead sulfate particles and lattice distortion. This allows fine graphene particles to more easily enter the cracks and lattice of the lead sulfate particles, thereby modifying the raw material to be modified. Due to the presence of fine graphene particles in the cracks and lattice of the lead sulfate particles, the modified material exhibits excellent electrical conductivity. Therefore, when used as the positive and / or negative active material in the electrode plates of lead-based batteries, it maintains excellent conductivity during charging and discharging, even when the positive active material or the proportion of lead sulfate in the positive active material is 100%. This ensures excellent conductivity and activity, significantly improving the specific capacity and specific power of lead-based batteries, preventing irreversible sulfation of the electrodes, and extending the battery's lifespan.

[0034] It should also be noted that in existing lead-based batteries, if deep discharge is not promptly recharged, dissolved lead sulfate will precipitate from the electrolyte. This precipitated lead sulfate adheres to the surface of the electrode plates, forming a dense white sulfate crystal layer. This non-conductive sulfate crystal layer disrupts the chemical and electrical connection between the electrolyte and the battery electrode plates. The raw materials to be modified in this invention, after being modified using the above-described modification method, maintain good conductivity, significantly enhancing the activity of the active materials. Consequently, a non-conductive sulfate crystal layer will not form on the electrode plates during use, preventing the formation of non-conductive interfaces and clumps on the surface and / or interior of the positive and / or negative active materials of the electrode plates, thus further extending the lifespan of the lead-based battery.

[0035] In a specific embodiment, the raw material to be modified also includes lead powder.

[0036] Step S10 also includes:

[0037] A diluted sulfuric acid solution, with a temperature between 60°C and 80°C, is added to the mixture. This allows the sulfuric acid in the diluted solution to react with the lead powder in the raw material to form lead sulfate. The temperature of the diluted sulfuric acid solution (60°C to 80°C) helps to increase the reaction rate and maintains the mixture at a high temperature, which facilitates the entry of graphene microparticles into the molecular lattice of lead sulfate during stirring in step S20, further enhancing the modification effect. Optionally, the concentration of the added diluted sulfuric acid solution can be between 10% and 50%, preferably 20%.

[0038] It should be noted that since lead sulfate is formed by the reaction of sulfuric acid with lead, lead powder can also be included in the raw materials. Since the active material recovered from lead-based batteries is a powder containing both lead sulfate and lead powder, in this embodiment, the raw material to be modified can be the powder recovered from the active material of lead-based batteries. This eliminates the need to melt and purify the recovered powder before use, reducing the cost of recycling lead-based batteries.

[0039] Furthermore, the step S20 is followed by the following step:

[0040] S30: The mixture 100 is rapidly cooled, causing the lead sulfate dissolved in the solution to precipitate out as fine crystals, forming a finely granulated modified substance (i.e., lead sulfate material), further enhancing the activity of the modified substance. Thus, since the active material of the recovered lead-based battery is a coarse powder with poor activity, recrystallizing the lead sulfate dissolved in the diluted sulfuric acid solution to form finely granulated lead sulfate powder further enhances the activity of the modified substance.

[0041] Furthermore, the impact ball 200 is an acid-resistant impact ball, thereby preventing the impact ball 200 from reacting with the sulfuric acid diluent. Preferably, the impact ball 200 is a zirconium ball, which, while ensuring that it does not react with the sulfuric acid diluent, has a high specific gravity, ensuring that it can form high-energy impacts on the molecular lattice of lead sulfate, causing cracks in the lead sulfate particles and lattice distortion of the molecular lattice.

[0042] Preferably, the high-speed stirring device 400 rotates at a speed greater than or equal to 3000 rpm, thereby using the high-speed rotation of the high-speed stirring device 400 to stir the mixture 100 at high speed, so that the zirconium balls form high-energy impacts on the molecular lattice of lead sulfate, causing cracks in the lead sulfate particles and lattice distortion of the molecular lattice.

[0043] Preferably, the nano-graphite powder contains graphene. On one hand, using nano-graphite powder makes the nano-graphite particles finer, making it easier for them to enter the lattice of lead sulfate molecules and the gaps between particles where the lattice is distorted. On the other hand, graphene is a graphene-based material... 2 A novel material, graphene, is a single-layer two-dimensional honeycomb lattice structure formed by the close packing of hybridized carbon atoms. Graphene itself possesses excellent electrical conductivity, and its distribution within lead sulfate materials further enhances the activity of the modified material, thus improving the modification effect. Nano-graphite powder containing graphene exhibits good electrical conductivity and permeability, easily penetrating into the cracks of lead sulfate particles and the distorted lattice of lead sulfate molecules, which is beneficial for further improving the modification effect.

[0044] Furthermore, the weight ratio of lead sulfate in mixture 100 to the graphene-containing nano-graphite powder is between 100:1 and 100:10.

[0045] Specifically, step S10 includes adding the raw material to be modified, graphite powder, sulfuric acid dilution and zirconium balls into the mixing tank 300.

[0046] Step S20 specifically includes: using a high-speed stirring device 400 to rotate at high speed in a stirring tank 300, causing zirconium balls to impact the molecular lattice of lead sulfate at high speed, thereby causing cracks in the lead sulfate particles and lattice distortion of the molecular lattice, which in turn allows the fine graphene particles to enter the particle cracks and the lattice distortion of the lead sulfate molecular lattice more smoothly, thus achieving modification.

[0047] Furthermore, the stirred tank 300 has acid resistance, thereby preventing the stirred tank 300 from reacting with the diluted sulfuric acid solution. Optionally, the stirred tank 300 is made of ultra-high molecular weight polymer material.

[0048] Furthermore, the high-speed stirring device 400 has acid resistance, thereby preventing it from reacting with the diluted sulfuric acid solution. Optionally, a protective layer made of ultra-high molecular weight material is formed on the surface of the high-speed stirring device 400. The high-speed stirring device 400 can be driven by a motor 500 to rotate at high speed.

[0049] Please see Figure 3 As shown, based on the above-described active material modification method, the present invention also provides a bipolar electrode plate 10, which includes a substrate 11, a positive current collector 12, a negative current collector 13, a positive active material layer 14, and a negative active material layer 15. The positive current collector 12 and the negative current collector 13 are respectively stacked on opposite sides of the substrate 11. The positive active material layer 14 is stacked on the side of the positive current collector 12 facing away from the substrate 11, and the negative active material layer 15 is stacked on the side of the negative current collector 13 facing away from the substrate 11. Both the negative active material layer 15 and the positive active material layer 14 include a modified material prepared using the active material modification method described in any of the above embodiments.

[0050] Based on the bipolar plate 10 described above, the present invention also provides a lead-based battery 600, including a plurality of bipolar plates 10 as described in any of the above embodiments, wherein the plurality of bipolar plates 10 are stacked.

[0051] Based on the lead-based battery 600 described above, the present invention also provides an energy storage device, which includes the lead-based battery 600 as described in any of the above embodiments. Specifically, the energy storage device can be applied in scenarios requiring energy storage and discharging, such as energy storage cabinets, electric vehicles, ships, spacecraft, and submarines, and is not limited thereto.

[0052] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0053] The embodiments described above are merely illustrative 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 patent. 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 these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for modifying an active substance, characterized in that, Including the following steps: The raw material to be modified is mixed with graphene-containing nano-graphite powder to form a mixture, and several impact balls are added; wherein, the raw material to be modified contains lead sulfate powder; The mixture is stirred using a high-speed stirring device, which causes cracks to form in the lead sulfate particles and lattice distortion to occur under the high-energy impact of the impacting ball, allowing graphene particles to enter the cracks and lattice of the lead sulfate particles.

2. The method for modifying active substances according to claim 1, characterized in that, The raw material to be modified also includes lead powder; The step of mixing the raw material to be modified with graphene-containing nano-graphite powder to form a mixture further includes: A sulfuric acid diluent is added to the mixture, the temperature of which is between 60°C and 80°C.

3. The method for modifying active substances according to claim 2, characterized in that, Following the step of stirring the mixture using a high-speed stirring device, the method further includes: The mixture is rapidly cooled, causing the lead sulfate dissolved in the solution to precipitate out as fine crystals.

4. The method for modifying active substances according to claim 3, characterized in that, The impact ball is a zirconium ball.

5. The method for modifying active substances according to claim 2, characterized in that, The concentration of the sulfuric acid dilution is between 10% and 50%.

6. The method for modifying active substances according to any one of claims 1 to 5, characterized in that, The high-speed stirring device has a rotation speed greater than or equal to 3000 rpm.

7. The method for modifying active substances according to any one of claims 1 to 5, characterized in that, The weight ratio of lead sulfate in the mixture to the graphene-containing nano-graphite powder is between 100:1 and 100:

10.

8. A bipolar electrode plate, characterized in that, The device includes a substrate, a positive current collector, a negative current collector, a positive active material layer, and a negative active material layer. The positive current collector and the negative current collector are respectively stacked on opposite sides of the substrate. The positive active material layer is stacked on the side of the positive current collector away from the substrate, and the negative active material layer is stacked on the side of the negative current collector away from the substrate. Both the negative electrode active material layer and the positive electrode active material layer comprise the modified material prepared according to the active material modification method according to any one of claims 1 to 7.

9. A lead-based battery, characterized in that, It includes a plurality of bipolar plates as described in claim 8, wherein the plurality of bipolar plates are stacked.

10. An energy storage device, characterized in that, Including the lead-based battery as described in any one of claims 9.

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