Battery slurry and preparation method thereof

Abstract

The invention discloses a battery slurry and a preparation method thereof, and the preparation method comprises the following steps: S1, adding a binder into a solvent, and then adding an electrode material or a solid electrolyte material to obtain a solid-liquid mixture; s2, adding a ball medium into the solid-liquid mixture; and S3, uniformly mixing the solid-liquid mixture in an oscillation manner to prepare the slurry for the battery, the oscillation frequency ranges from 500 Hz to 2000 Hz, and the oscillation time ranges from 300 min to 500 min. The spherical medium is introduced into the slurry system, the synergistic effect of the spherical medium and oscillation treatment is utilized, and meanwhile the problems that shearing force is insufficient and different areas of the slurry are different when the slurry is prepared through traditional stirring are solved. According to the invention, the particle aggregation phenomenon in the slurry is obviously reduced, the stability of the uniformity of the slurry is improved, and the surface defects such as pits and scratches in a coated product are obviously reduced; and uniform and fine high-quality slurry is obtained.

Description

A slurry for batteries and its preparation method Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a slurry for batteries and its preparation method. Background Technology

[0002] In current technological practices, slurry preparation is a crucial step affecting subsequent coating processes and the performance of the final product. Existing preparation technologies typically aim to achieve uniform distribution of solid components in a liquid medium through processes such as mixing and dispersion. However, these existing technologies generally face several shortcomings that urgently need to be addressed. Specifically, the prepared slurries often exhibit unstable uniformity and a tendency for particle agglomeration, leading to surface defects such as pitting during subsequent coating processes. These shortcomings directly affect the uniformity and consistency of the coating, thus adversely impacting the electrochemical performance and reliability of the product.

[0003] Therefore, existing technologies still need improvement and development. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a slurry for batteries and a method for preparing the same, in order to solve the problems of unstable uniformity and easy agglomeration of particles in the slurry prepared by the prior art.

[0005] The technical solution of the present invention is as follows: In the first aspect, the present invention provides a method for preparing a slurry for batteries, comprising the following steps: S1, adding a binder to a solvent, and then adding an electrode material or a solid electrolyte material to obtain a solid-liquid mixture; S2, adding a spherical medium to the solid-liquid mixture; S3, mixing the solid-liquid mixture uniformly by shaking to obtain the slurry for batteries; wherein the shaking frequency is 500-2000Hz and the shaking time is 300-500min.

[0006] Optionally, the diameter of the sphere medium is 2-10 mm.

[0007] Optionally, the ball-to-material ratio is 0.2-5:1.

[0008] Optionally, the material of the sphere medium is any one of zirconium oxide, alumina, agate, stainless steel, and tungsten carbide.

[0009] Optionally, the solvent is one or more of tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, acetonitrile, dioxane, methyl ethyl ketone, toluene, xylene, anisole, butyl acetate, methyl acetate, ethyl acetate, butyl butyrate, and isobutyl isobutyrate.

[0010] Optionally, the adhesive is one or more of carboxymethyl cellulose, polymethyl methacrylate, polyisobutylene, nitrile rubber, cis-butadiene rubber, styrene-butadiene rubber, polyacrylonitrile, polytetrafluoroethylene, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, and polystyrene-butadiene-styrene.

[0011] Optionally, the solid electrolyte material is Li3PS4 or Li7P3S. 11 Li 10 GeP2S 12 Li 3.833 Sn 0.867 S4, Li 6- y PS 5-y X 1+y X is one or more of Cl, Br, I, and F, and y ranges from 0 to 2.0; and / or, the solid electrolyte material is granular with a particle size of 0.5-15 μm.

[0012] Optionally, the electrode material is a positive electrode material or a negative electrode material.

[0013] Preferably, the positive electrode material is a layered oxide, a polyanionic compound, or a spinel oxide; the negative electrode material is one or more of graphite-based, lithium titanate, nano-silicon, and silicon-carbon composite.

[0014] In a second aspect, the present invention provides a slurry for batteries, which is prepared by the above-described preparation method.

[0015] Beneficial Effects: This invention provides a battery slurry and its preparation method. Compared with existing technologies, the advantages of this invention are: 1. This invention introduces a spherical medium into the slurry system and drives the spherical medium to mix with the slurry through oscillation and vibration. This utilizes the synergistic effect of the spherical medium and oscillation treatment to achieve strong dispersion and global homogenization without relying on traditional stirring and shearing. This significantly reduces particle agglomeration in the slurry, improves the stability of slurry uniformity, and significantly reduces surface defects such as pitting and scratches in coated products. In other words, this invention produces a uniform and fine high-quality slurry and ultimately achieves a smooth coating effect without pitting, significantly improving the overall preparation quality of the slurry and the consistency of the appearance and performance of the coated products.

[0016] 2. This invention utilizes the synergistic effect of spherical media and vibration treatment to fundamentally optimize the dispersion and mixing process of slurry, and can simultaneously solve the problems of insufficient shear force and differences in different regions of slurry when preparing slurry by traditional stirring. Attached Figure Description

[0017] Figure 1 is a diagram showing the effect of the solid electrolyte slurry prepared in Example 1 of the present invention after coating.

[0018] Figure 2 is a diagram showing the effect of coating the positive electrode slurry obtained in Example 2 of the present invention.

[0019] Figure 3 is a diagram showing the effect of coating the negative electrode slurry obtained in Example 3 of the present invention.

[0020] Figure 4 shows the effect of coating the solid electrolyte slurry prepared in Comparative Example 1 of the present invention.

[0021] Figure 5 shows the effect of coating the solid electrolyte slurry prepared in Comparative Example 2 of the present invention. Detailed Implementation

[0022] This invention provides a slurry for batteries and a method for preparing the same. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below.

[0023] In existing technologies, the prepared slurries often exhibit unstable uniformity and a tendency for particle agglomeration, leading to surface defects such as pitting during subsequent coating processes. This is primarily due to insufficient shear force provided by the stirring process in current preparation methods, which fails to effectively break up particle agglomeration. Simultaneously, significant differences in flow rate and shear force exist across different regions of the mixing container, resulting in uneven local composition and dispersion. This leads to overall instability in the quality of slurries produced by existing technologies, making them prone to defects.

[0024] Based on this, embodiments of the present invention provide a method for preparing a battery slurry, comprising the following steps: S1, adding a binder to a solvent, and then adding an electrode material or a solid electrolyte material to obtain a solid-liquid mixture; S2, adding a spherical medium to the solid-liquid mixture; S3, mixing the solid-liquid mixture uniformly by shaking to obtain the battery slurry; wherein the shaking frequency is 500-2000Hz and the shaking time is 300-500min.

[0025] This invention employs a spherical medium-assisted oscillation treatment method, enabling the slurry system to achieve a more thorough and uniform dispersion and mixing effect. Specifically, a spherical medium is introduced into the slurry system, and the spherical medium is mixed with the slurry through oscillation and vibration, which fundamentally optimizes the dispersion and mixing process of the slurry, and simultaneously overcomes insufficient shear force and eliminates performance differences between different regions within the slurry. Therefore, the slurry prepared by this invention has the following beneficial effects: (1) Reduces particle agglomeration and improves the stability of slurry uniformity: The high-quality slurry prepared by this invention is uniform and delicate, which not only effectively reduces particle agglomeration, but also improves the stability of solid electrolyte materials or electrode materials in the slurry; (2) Reduces coating defects: The slurry prepared by this invention can achieve a smooth coating effect without pitting. Compared with existing stirring or homogenization treatments, it not only significantly reduces surface defects such as pitting, streaks, pinholes and particle protrusions, but also significantly improves the appearance and performance consistency of the coated products; (3) Since the quality of the slurry and the appearance and performance consistency of its coated products are significantly improved, the differences between different batches can be reduced.

[0026] In some embodiments, the diameter of the spherical medium is 2-10 mm. Preferably, the diameter of the spherical medium is 2-5 mm.

[0027] In this embodiment, a sphere diameter of 2-10 mm provides better dispersion for easily agglomerated powders. If the sphere size is smaller than this range, it is difficult to ensure that the dispersed powder maintains its original size. If the sphere size is larger than this range, it is difficult to guarantee the aforementioned dispersion effect on the dispersed particles. Preferably, the sphere diameter is 2-5 mm. Selecting slightly smaller spheres within this range can appropriately reduce the sphere-to-powder ratio while ensuring dispersion effect, thereby saving costs.

[0028] In some embodiments, the ball-to-material ratio is 0.2-5:1.

[0029] In some embodiments, the material of the spherical medium is any one of zirconium oxide, aluminum oxide, agate, stainless steel, and tungsten carbide.

[0030] In some embodiments, the solvent is one or more of tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, acetonitrile, dioxane, methyl ethyl ketone, toluene, xylene, anisole, butyl acetate, methyl acetate, ethyl acetate, butyl butyrate, and isobutyl isobutyrate.

[0031] In some embodiments, the adhesive is one or more of carboxymethyl cellulose, polymethyl methacrylate, polyisobutylene, nitrile rubber, cis-butadiene rubber, styrene-butadiene rubber, polyacrylonitrile, polytetrafluoroethylene, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, and polystyrene-butadiene-styrene.

[0032] In some embodiments, the solid electrolyte material is Li3PS4 or Li7P3S. 11 Li 10 GeP2S 12 Li 3.833 Sn 0.867 S4, Li 6-y PS 5-y X 1+y X is one or more of Cl, Br, I, and F, and y ranges from 0 to 2.0; and / or, the solid electrolyte material is granular with a particle size of 0.5-15 μm.

[0033] In some embodiments, the electrode material is a positive electrode material or a negative electrode material.

[0034] In some embodiments, the positive electrode material is a layered oxide, a polyanionic compound, or a spinel oxide; the negative electrode material is one or more of graphite-based, elemental lithium, lithium titanate, nano-silicon, and silicon-carbon composite.

[0035] The layered oxide is LiCoO2 or LiNi. x Co y Mn Z O2 (x+y+z=1) or LiNi x Co y Al z O2 (NCA); the polyanionic compound is LiFePO4 or LiMn x Fe 1-x PO4 (0 < x < 1); the spinel-type oxide is LiMn2O4.

[0036] More preferably, in step S1, a binder is added to the solvent, and then an electrode material is added to obtain a solid-liquid mixture, and a conductive agent is also added; the conductive agent is one or more of acetylene black, conductive carbon black, graphite, metal fiber, carbon nanofiber, carbon nanotube, and graphene.

[0037] An embodiment of the present invention provides a battery slurry, which is prepared by the above-described preparation method.

[0038] The present invention will be further described below through specific embodiments.

[0039] Example 1 This example provides a solid electrolyte slurry and its preparation method, as follows: (1) Add 42 mL of ethyl acetate (solvent) to a zirconium oxide bottle.

[0040] (2) Add 1.2g of polystyrene-butadiene-styrene (binder) to ethyl acetate.

[0041] (3) Add 15g of Li6PS5Cl (LPSC) powder to the above system to form a solid-liquid mixture.

[0042] (4) Add 5g of zirconia balls (5mm in diameter) to the solid-liquid mixture above; then seal the zirconia bottle.

[0043] (5) Place the sealed zirconium oxide bottle on a vibrating mixer for vibration treatment to obtain electrolyte slurry; wherein the vibration frequency of the vibrating mixer is 500 Hz and the time is 300 min.

[0044] (6) The obtained electrolyte slurry is coated into an electrolyte membrane with a thickness of 150 μm, and then the electrolyte membrane is dried at 100 °C to obtain the electrolyte membrane shown in Figure 1.

[0045] As shown in Figure 1, the electrolyte membrane prepared in Example 1 is free of defects such as pitting and scratches, and the membrane is uniform and flat.

[0046] Example 2 This example provides a positive electrode slurry and its preparation method, as follows: (1) Add 37 mL of isobutyl isobutyrate (solvent) to a zirconium oxide bottle.

[0047] (2) Add 0.8g of nitrile rubber (adhesive) to isobutyl isobutyrate.

[0048] (3) Add 15g of positive electrode powder (NCM811:VGCF:LPSC=80:5:15) to the above system to form a solid-liquid mixture.

[0049] (4) Add 3g of agate balls (5mm in diameter) to the solid-liquid mixture; then seal the zirconium oxide bottle.

[0050] (5) Place the sealed zirconium oxide bottle on a vibrating mixer for vibration treatment to obtain positive electrode slurry; wherein the vibration frequency of the vibrating mixer is 750 Hz and the time is 420 min.

[0051] (6) The positive electrode slurry is coated into a positive electrode film with a thickness of 150 μm, and then the positive electrode film is dried at 100 °C to obtain the positive electrode film shown in Figure 2.

[0052] As shown in Figure 2, the positive electrode film prepared in Example 2 is free of defects such as pitting and scratches, and the film is uniform and flat.

[0053] Example 3 This example provides a negative electrode slurry and its preparation method, as follows: (1) Add 45 mL of ethyl acetate (solvent) to a zirconium oxide bottle.

[0054] (2) Add 1.0g of carboxymethyl cellulose (binder) to ethyl acetate.

[0055] (3) Add 15g of negative electrode powder (graphite:LPSC=80:20) to the above system to form a solid-liquid mixture.

[0056] (4) Add 4.5g of agate balls (6mm in diameter) to the solid-liquid mixture; then seal the zirconium oxide bottle.

[0057] (5) Place the sealed zirconium oxide bottle on a vibrating mixer for vibration treatment to obtain negative electrode slurry; wherein the vibration frequency of the vibrating mixer is 1000Hz and the time is 360min.

[0058] (6) The negative electrode slurry is coated into a negative electrode film with a thickness of 150 μm, and then the negative electrode film is dried at 100 °C to obtain the negative electrode film shown in Figure 3.

[0059] As shown in Figure 3, the negative electrode film prepared in Example 3 is free of defects such as pitting and scratches, and the film is uniform and flat.

[0060] Comparative Example 1 This example provides an electrolyte slurry and its preparation method. Compared with Example 1, this comparative example uses a stirring method to prepare an electrolyte membrane, as follows: (1) Add 42 mL of ethyl acetate (solvent) to a zirconium oxide bottle.

[0061] (2) Add 1.2g of polystyrene-butadiene-styrene (binder) to ethyl acetate.

[0062] (3) Add 15g of Li6PS5Cl powder to the above system to form a solid-liquid mixture.

[0063] (4) The above solid-liquid mixture is processed by stirring to obtain an electrolyte slurry; wherein the stirring rate is 1200 rpm and the time is 300 min.

[0064] (5) The obtained electrolyte slurry is coated into an electrolyte membrane with a thickness of 150 μm, and then the electrolyte membrane is dried at 100 °C to obtain the electrolyte membrane shown in Figure 4.

[0065] As shown in Figure 4, the electrolyte membrane prepared in Comparative Example 1 has obvious pitting compared to the electrolyte membrane prepared in Example 1.

[0066] Comparative Example 2 This example provides an electrolyte slurry and its preparation method. Compared with Example 1, this comparative example uses a homogenization method to prepare the electrolyte membrane, as follows: (1) Add 42 mL of ethyl acetate (solvent) to a zirconium oxide bottle.

[0067] (2) Add 1.2g of polystyrene-butadiene-styrene (binder) to ethyl acetate.

[0068] (3) Add 15g of Li6PS5Cl powder to the above system to form a solid-liquid mixture.

[0069] (4) The above solid-liquid mixture is processed by homogenization stirring to obtain electrolyte slurry; wherein the stirring rate is 9000 rpm, the stirring time is 5 min, and the process is repeated 8 times with an interval of about 5 min between each time.

[0070] (5) The obtained electrolyte slurry is coated into an electrolyte membrane with a thickness of 150 μm, and then the electrolyte membrane is dried at 100 °C to obtain the electrolyte membrane shown in Figure 5.

[0071] As can be seen from Figure 5, the electrolyte membrane prepared in Comparative Example 2 is significantly less uniformly coated compared to the electrolyte membrane prepared in Example 1.

[0072] In summary, this invention employs a spherical medium-assisted oscillation treatment method. Through the synergistic effect of both, it aims to simultaneously overcome insufficient shear force and eliminate performance differences between different regions within the slurry. This invention fundamentally optimizes the dispersion and mixing process of the slurry, thereby obtaining a uniform and fine high-quality slurry, and ultimately achieving a smooth coating effect without pitting. Overall, it significantly improves the preparation quality of the slurry and the consistency of the appearance and performance of the coated product.

[0073] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for preparing a slurry for batteries, characterized in that, Includes the following steps: S1. Add a binder to the solvent, then add electrode material or solid electrolyte material to obtain a solid-liquid mixture; S2. Add a spherical medium to the solid-liquid mixture; S3. Mix the solid-liquid mixture evenly by shaking to obtain the battery slurry; the shaking frequency is 500-2000Hz, and the shaking time is 300-500min.

2. The preparation method according to claim 1, characterized in that, The diameter of the sphere medium is 2-10 mm.

3. The preparation method according to claim 1, characterized in that, The ball-to-material ratio is 0.2-5:

1.

4. The preparation method according to claim 1, characterized in that, The material of the sphere medium is any one of zirconium oxide, aluminum oxide, agate, stainless steel, and tungsten carbide.

5. The preparation method according to claim 1, characterized in that, The solvent is one or more of tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, acetonitrile, dioxane, methyl ethyl ketone, toluene, xylene, anisole, butyl acetate, methyl acetate, ethyl acetate, butyl butyrate, and isobutyl isobutyrate.

6. The preparation method according to claim 1, characterized in that, The adhesive is one or more of the following: carboxymethyl cellulose, polymethyl methacrylate, polyisobutylene, nitrile rubber, cis-butadiene rubber, styrene-butadiene rubber, polyacrylonitrile, polytetrafluoroethylene, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, and polystyrene-butadiene-styrene.

7. The preparation method according to claim 1, characterized in that, The solid electrolyte material is Li3PS4 or Li7P3S. 11 Li 10 GeP2S 12 Li 3.833 Sn 0.867 S4, Li 6-y PS 5-y X 1+y X is one or more of Cl, Br, I, and F, and y ranges from 0 to 2.0; and / or, the solid electrolyte material is granular with a particle size of 0.5-15 μm.

8. The preparation method according to claim 1, characterized in that, The electrode material is either a positive electrode material or a negative electrode material.

9. The preparation method according to claim 8, characterized in that, The positive electrode material is a layered oxide, a polyanionic compound, or a spinel oxide; the negative electrode material is one or more of graphite-based, lithium titanate, nano-silicon, and silicon-carbon composite.

10. A slurry for batteries, characterized in that, The battery slurry is prepared by the preparation method described in any one of claims 1-9.

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