A method for preparing ceramic slurry for solid-state battery

Abstract

The present invention discloses a method for preparing ceramic slurry for solid-state batteries, which specifically includes the following steps: S1, raw material selection and proportioning; S2, mixing and dispersing process; S3, slurry post-treatment; S4, slurry application and battery assembly; the raw materials include ceramic powder, binder, thickener and solvent, and the present invention relates to the technical field of solid-state batteries. The method for preparing ceramic slurry for solid-state batteries effectively solves the agglomeration problem of ceramic particles through fine raw material proportioning and innovative mixing and dispersing process, realizes uniform dispersion of ceramic particles in slurry, viscosity adjustment and vacuum degassing treatment, ensures the stability and fluidity of slurry, is conducive to subsequent coating and battery assembly, and homogenization treatment improves the interface contact quality between slurry and electrode material, reduces interface resistance, and improves the electrochemical performance of battery. The assembled solid-state battery shows significant advantages in energy density, cycle stability and safety.

Description

Technical Field

[0001] The present invention relates to the technical field of solid-state batteries, and in particular to a method for preparing ceramic slurry for solid-state batteries. Background Art

[0002] A solid-state battery is a battery that uses solid electrodes and solid electrolytes. The negative electrode material of a solid-state battery can be a composite negative electrode of nano-silicon and graphite, and the positive electrode can be lithium manganese oxide, a lithium-rich manganese-based material, or a lithium-free positive electrode material. The electrolyte is a solid electrolyte with an energy density of 300-450 watt-hours / kilogram. Solid-state batteries use solid electrolytes to replace the electrolytes and diaphragms of traditional lithium-ion batteries. They are safer, have higher energy density, and have stronger cycle performance. They have become the main research and development direction of the next generation of power batteries. Solid electrolytes can be roughly divided into three categories: inorganic electrolytes, solid polymer electrolytes, and composite electrolytes. Since the power-to-weight ratio of solid-state batteries is relatively high, they are ideal batteries for electric vehicles.

[0003] As the core of the next generation of energy storage technology, solid-state batteries have attracted much attention due to their high safety, long cycle life and potential high energy density. However, problems such as particle agglomeration, uneven dispersion, and difficulty in viscosity control in the preparation process of ceramic electrolyte slurry have seriously restricted the improvement of solid-state battery performance. In the existing technology, although there are a variety of ceramic slurry preparation methods, they often have defects such as complex process, high cost, low efficiency or unstable product performance. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a method for preparing a ceramic slurry for a solid-state battery, which solves the problems mentioned in the above background technology.

[0005] To achieve the above objectives, the present invention is implemented by the following technical scheme: A method for preparing ceramic slurry for solid-state batteries, specifically comprising the following steps:

[0006] S1. Raw material selection and proportion: select ceramic materials with high ionic conductivity, low electronic conductivity and good chemical stability, binders with excellent bonding, electrochemical stability and thermal stability, dispersants that promote uniform dispersion of particles, and organic solvents that have good solubility for ceramic powders, binders and dispersants;

[0007] S2. Mixing and dispersion process:

[0008] (1) Pre-dispersion: First, the ceramic powder is mixed with a portion of the solvent, accounting for 20%-30% of the total solvent, and dispersed in a high-speed shear disperser at a speed of 5000-10000 rpm for 10-20 minutes to initially break up the particle agglomerates;

[0009] (2) Adding binder and dispersant: Then, slowly add binder and dispersant and continue to disperse at the same speed for 10-15 minutes to ensure that all components are evenly mixed;

[0010] (3) High shear and ultrasonic dispersion: Finally, the remaining solvent is added and a high shear disperser combined with ultrasonic dispersion is used at a speed of 10,000-15,000 rpm and an ultrasonic frequency of 20-40 kHz for 30-60 minutes to achieve the ultimate dispersion of the ceramic particles;

[0011] S3, slurry post-treatment:

[0012] (1) Vacuum degassing: Place the slurry in a vacuum degassing machine and degas at a pressure of -0.1 MPa for 1-2 hours to completely remove the bubbles in the slurry;

[0013] (2) Homogenization: Use a high-pressure homogenizer to homogenize the slurry, with the pressure set at 20-50 MPa, and repeat 2-3 times to further improve the uniformity and stability of the slurry;

[0014] S4. Slurry application and battery assembly: The prepared ceramic slurry is evenly coated on the electrode surface of the solid-state battery. After drying, curing and other process treatments, it is assembled with the positive and negative electrode materials into a complete solid-state battery.

[0015] Preferably, the raw materials include ceramic powder, binder, thickener and solvent, wherein the mass proportion of ceramic powder is 40-50%, the mass proportion of binder is 1-5%, the mass ratio of thickener is 1.5-9:1 of high viscosity thickener and low viscosity thickener, the total mass proportion is 0.03-1%, and the mass proportion of solvent is 48.9-58.87%.

[0016] Preferably, the ceramic material is selected from one of lithium lanthanum zirconium oxide, lithium aluminum germanium phosphide or lithium silicon phosphorus oxide nitrogen, the binder is selected from one of polyvinylidene fluoride, polyvinyl alcohol or polyimide, the dispersant is selected from one of sodium dodecyl sulfate, polyethylene glycol or sodium polyacrylate, and the solvent is selected from one of N-methylpyrrolidone, dimethylformamide or dimethylacetamide.

[0017] Preferably, in S1, before mixing and dispersing, the ceramic powder is ground to ensure uniform particle size distribution without large particle agglomeration, and at the same time, the solvent is dehydrated to avoid the influence of moisture on the slurry performance.

[0018] Preferably, in S2(3), a high shear disperser with high shear force and good dispersing effect is selected, and one of a planetary high shear disperser or a colloid mill is used.

[0019] Preferably, in S2(2), a double planetary mixer is used to stir at an orbital speed of 10-15 rpm and a dispersion speed of 800-1200 rpm for 20-40 min. After scraping the cylinder, the mixture is stirred at an orbital speed of 20-30 rpm and a dispersion speed of 2800-3000 rpm for 60-180 min to obtain a ceramic slurry.

[0020] Preferably, in S4, coating is performed by one of blade coating, spraying or printing.

[0021] Beneficial Effects

[0022] The present invention provides a method for preparing ceramic slurry for solid-state batteries. Compared with the prior art, the method has the following beneficial effects: the method for preparing ceramic slurry for solid-state batteries specifically includes the following steps: S1, raw material selection and proportioning; S2, mixing and dispersing process; S3, slurry post-treatment; S4, slurry application and battery assembly; through fine raw material proportioning and innovative mixing and dispersing process, the agglomeration problem of ceramic particles is effectively solved, and the uniform dispersion of ceramic particles in the slurry is achieved. Viscosity adjustment and vacuum degassing treatment ensure the stability and fluidity of the slurry, which is beneficial to subsequent coating and battery assembly. The homogenization treatment improves the interface contact quality between the slurry and the electrode material, reduces the interface resistance, and improves the electrochemical performance of the battery. The assembled solid-state battery shows significant advantages in energy density, cycle stability and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flow chart of the steps of the present invention. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] See also Figure 1 The present invention provides a technical solution: a method for preparing ceramic slurry for solid-state batteries, which specifically includes the following embodiments:

[0026] Embodiment 1

[0027] S1. Raw material selection and proportion: select ceramic materials with high ionic conductivity, low electronic conductivity and good chemical stability, binders with excellent bonding, electrochemical stability and thermal stability, dispersants that promote uniform dispersion of particles, and organic solvents that have good solubility for ceramic powders, binders and dispersants;

[0028] S2. Mixing and dispersion process:

[0029] (1) Pre-dispersion: First, the ceramic powder was mixed with a portion of the solvent, accounting for 25% of the total solvent, and dispersed in a high-speed shear disperser at a speed of 7500 rpm for 15 minutes to preliminarily break up the particle agglomerates;

[0030] (2) Adding binder and dispersant: Then, slowly add binder and dispersant and continue to disperse at the same speed for 13 minutes to ensure that all components are evenly mixed;

[0031] (3) High shear and ultrasonic dispersion: Finally, the remaining solvent was added and a high shear disperser combined with ultrasonic dispersion was used at a speed of 12,500 rpm and an ultrasonic frequency of 30 kHz for 45 minutes to achieve the ultimate dispersion of the ceramic particles;

[0032] S3, slurry post-treatment:

[0033] (1) Vacuum degassing: The slurry is placed in a vacuum degassing machine and degassed at a pressure of -0.1 MPa for 1.5 hours to completely remove the bubbles in the slurry;

[0034] (2) Homogenization: The slurry was homogenized using a high-pressure homogenizer with the pressure set at 35 MPa, and the process was repeated twice to further improve the uniformity and stability of the slurry.

[0035] S4. Slurry application and battery assembly: The prepared ceramic slurry is evenly coated on the electrode surface of the solid-state battery. After drying, curing and other process treatments, it is assembled with the positive and negative electrode materials into a complete solid-state battery.

[0036] Embodiment 2

[0037] S1. Raw material selection and proportion: select ceramic materials with high ionic conductivity, low electronic conductivity and good chemical stability, binders with excellent bonding, electrochemical stability and thermal stability, dispersants that promote uniform dispersion of particles, and organic solvents that have good solubility for ceramic powders, binders and dispersants;

[0038] S2. Mixing and dispersion process:

[0039] (1) Pre-dispersion: First, the ceramic powder was mixed with a portion of the solvent, accounting for 20% of the total solvent, and dispersed in a high-speed shear disperser at a speed of 5000 rpm for 10 minutes to preliminarily break up the particle agglomerates;

[0040] (2) Adding binder and dispersant: Then, slowly add binder and dispersant and continue to disperse at the same speed for 10 minutes to ensure that all components are evenly mixed;

[0041] (3) High shear and ultrasonic dispersion: Finally, the remaining solvent was added and a high shear disperser combined with ultrasonic dispersion was used at a speed of 10,000 rpm and an ultrasonic frequency of 20 kHz for 30 minutes to achieve the ultimate dispersion of the ceramic particles;

[0042] S3, slurry post-treatment:

[0043] (1) Vacuum degassing: The slurry is placed in a vacuum degassing machine and degassed at a pressure of -0.1 MPa for 1 hour to completely remove the bubbles in the slurry;

[0044] (2) Homogenization: The slurry was homogenized using a high-pressure homogenizer with the pressure set at 20 MPa, and repeated twice to further improve the uniformity and stability of the slurry;

[0045] S4. Slurry application and battery assembly: The prepared ceramic slurry is evenly coated on the electrode surface of the solid-state battery. After drying, curing and other process treatments, it is assembled with the positive and negative electrode materials into a complete solid-state battery.

[0046] Embodiment 3

[0047] S1. Raw material selection and proportion: select ceramic materials with high ionic conductivity, low electronic conductivity and good chemical stability, binders with excellent bonding, electrochemical stability and thermal stability, dispersants that promote uniform dispersion of particles, and organic solvents that have good solubility for ceramic powders, binders and dispersants;

[0048] S2. Mixing and dispersion process:

[0049] (1) Pre-dispersion: First, the ceramic powder is mixed with a portion of the solvent, accounting for 30% of the total solvent, and dispersed in a high-speed shear disperser at a speed of 10,000 rpm for 20 minutes to preliminarily break up the particle agglomerates;

[0050] (2) Adding binder and dispersant: Then, slowly add binder and dispersant and continue to disperse at the same speed for 15 minutes to ensure that all components are evenly mixed;

[0051] (3) High shear and ultrasonic dispersion: Finally, the remaining solvent was added and a high shear disperser combined with ultrasonic dispersion was used at a speed of 15,000 rpm and an ultrasonic frequency of 40 kHz for 60 minutes to achieve the ultimate dispersion of the ceramic particles;

[0052] S3, slurry post-treatment:

[0053] (1) Vacuum degassing: The slurry is placed in a vacuum degassing machine and degassed at a pressure of -0.1 MPa for 2 hours to completely remove the bubbles in the slurry;

[0054] (2) Homogenization: The slurry was homogenized using a high-pressure homogenizer with the pressure set at 50 MPa and repeated three times to further improve the uniformity and stability of the slurry;

[0055] S4. Slurry application and battery assembly: The prepared ceramic slurry is evenly coated on the electrode surface of the solid-state battery. After drying, curing and other process treatments, it is assembled with the positive and negative electrode materials into a complete solid-state battery.

[0056] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0057] Effect Example

[0058] At a test temperature of 25°C, the charge and discharge current was 1.67A / g (1C), the charge and discharge voltage range was 1.7-2.8V, and the number of cycles was 1000. The test results of the first discharge capacity and the capacity retention rate after 1000 cycles were as follows. The assembled button cells were charged and discharged at 2.0-4.6V and 0.1C to evaluate the first discharge specific capacity and the first coulomb efficiency of each positive electrode material; the assembled button cells were cycled 50 times at 2.0-4.6V and 0.2C to evaluate the cycle performance and voltage attenuation of the positive electrode material. See the table below for details:

[0059]

[0060] It can be seen from the above table that: through fine raw material ratios and innovative mixing and dispersion processes, the agglomeration problem of ceramic particles is effectively solved, and the uniform dispersion of ceramic particles in the slurry is achieved. Viscosity adjustment and vacuum degassing treatment ensure the stability and fluidity of the slurry, which is beneficial to subsequent coating and battery assembly. The homogenization treatment improves the interface contact quality between the slurry and the electrode material, reduces the interface resistance, and improves the electrochemical performance of the battery. The assembled solid-state batteries show significant advantages in energy density, cycle stability and safety.

[0061] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0062] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing ceramic slurry for solid-state batteries, characterized in that: The specific steps include: S1. Raw material selection and proportion: select ceramic materials with high ionic conductivity, low electronic conductivity and good chemical stability, binders with excellent bonding, electrochemical stability and thermal stability, dispersants that promote uniform dispersion of particles, and organic solvents that have good solubility for ceramic powders, binders and dispersants; S2. Mixing and dispersion process: (1) Pre-dispersion: First, the ceramic powder is mixed with a portion of the solvent, accounting for 20%-30% of the total solvent, and dispersed in a high-speed shear disperser at a speed of 5000-10000 rpm for 10-20 minutes to initially break up the particle agglomerates; (2) Adding binder and dispersant: Then, slowly add binder and dispersant and continue to disperse at the same speed for 10-15 minutes to ensure that all components are evenly mixed; (3) High shear and ultrasonic dispersion: Finally, the remaining solvent is added and a high shear disperser combined with ultrasonic dispersion is used at a speed of 10,000-15,000 rpm and an ultrasonic frequency of 20-40 kHz for 30-60 minutes to achieve the ultimate dispersion of the ceramic particles; S3, slurry post-treatment: (1) Vacuum degassing: Place the slurry in a vacuum degassing machine and degas at a pressure of -0.1 MPa for 1-2 hours to completely remove the bubbles in the slurry; (2) Homogenization: Use a high-pressure homogenizer to homogenize the slurry, with the pressure set at 20-50 MPa, and repeat 2-3 times to further improve the uniformity and stability of the slurry; S4. Slurry application and battery assembly: The prepared ceramic slurry is evenly coated on the electrode surface of the solid-state battery. After drying, curing and other process treatments, it is assembled with the positive and negative electrode materials into a complete solid-state battery.

2. The method for preparing a ceramic slurry for a solid-state battery according to claim 1, characterized in that: The raw materials include ceramic powder, binder, thickener and solvent, wherein the mass proportion of ceramic powder is 40-50%, the mass proportion of binder is 1-5%, the mass ratio of thickener is 1.5-9:1 of high viscosity thickener and low viscosity thickener, the total mass proportion is 0.03-1%, and the mass proportion of solvent is 48.9-58.87%.

3. The method for preparing a ceramic slurry for a solid-state battery according to claim 1, characterized in that: The ceramic material is selected from one of lithium lanthanum zirconium oxide, lithium aluminum germanium phosphide or lithium silicon phosphorus oxide nitrogen, the binder is selected from one of polyvinylidene fluoride, polyvinyl alcohol or polyimide, the dispersant is selected from one of sodium dodecyl sulfate, polyethylene glycol or sodium polyacrylate, and the solvent is selected from one of N-methylpyrrolidone, dimethylformamide or dimethylacetamide.

4. The method for preparing a ceramic slurry for a solid-state battery according to claim 1, characterized in that: In S1, before mixing and dispersing, the ceramic powder is ground to ensure uniform particle size distribution without large particle agglomeration. At the same time, the solvent is dehydrated to avoid the influence of moisture on the slurry performance.

5. The method for preparing a ceramic slurry for a solid-state battery according to claim 1, characterized in that: In S2(3), a high shear disperser with high shear force and good dispersing effect is selected, and one of a planetary high shear disperser or a colloid mill is used.

6. The method for preparing a ceramic slurry for a solid-state battery according to claim 1, characterized in that: In S2(2), a double planetary mixer is used to stir at an orbital speed of 10-15 rpm and a dispersion speed of 800-1200 rpm for 20-40 min. After scraping the cylinder, the mixture is stirred at an orbital speed of 20-30 rpm and a dispersion speed of 2800-3000 rpm for 60-180 min to obtain a ceramic slurry.

7. The method for preparing a ceramic slurry for a solid-state battery according to claim 1, characterized in that: In S4, coating is performed by a method selected from the group consisting of blade coating, spraying, and printing.

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