Method for producing a sulfide electrolyte layer
By coating a mixed slurry onto the electrode and then drying it, the preparation process of the sulfide electrolyte layer is simplified, the problem of high energy consumption caused by multiple solvent removal and drying operations is solved, and more efficient production and cost reduction are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- REASOLID (QUZHOU) NEW MATERIAL TECH CO LTD
- Filing Date
- 2024-12-02
- Publication Date
- 2026-06-02
AI Technical Summary
The existing process for preparing sulfide electrolyte layers requires multiple solvent removal and drying operations, resulting in a complex process with high energy consumption, which is not conducive to simplification and cost reduction.
The mixed slurry is coated onto the electrode and the sulfide electrolyte layer is prepared simultaneously through a drying process. By combining stirring, ball milling and filtration steps, repeated desolvation is avoided. The preparation and modification of the sulfide solid electrolyte layer are completed simultaneously through the electrode drying process.
It simplifies the preparation process, reduces energy consumption, improves the convenience of material transportation and the ability to isolate water and oxygen, reduces production costs, and is conducive to industrialization.
Smart Images
Figure CN122136449A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of solid-state battery technology, and more specifically, to a method for preparing a sulfide electrolyte layer. Background Technology
[0002] Solid-state batteries are a new type of battery technology that uses solid electrolytes instead of traditional liquid electrolytes. Solid electrolytes can be materials such as ceramics, polymers, or sulfides. During charging and discharging, lithium ions migrate between the positive and negative electrodes through the solid electrolyte to complete the electrochemical reaction. Compared to traditional lithium-ion batteries, solid-state batteries have significant advantages in safety, energy density, and cycle life, and are expected to be widely used in electric vehicles, energy storage systems, portable electronic devices, and military and aerospace applications.
[0003] Typically, the preparation of sulfide electrolyte layers involves first removing the solvent from the mixed electrolyte precursor slurry and then heat-treating it to synthesize it. Next, solvents and binders are added to the synthesized solid electrolyte powder to prepare a composite electrolyte slurry. The composite electrolyte slurry is then coated onto the electrode of a lithium-ion battery and subjected to heat drying again. This process requires multiple solvent removal and drying operations, which is not conducive to saving processes and reducing energy consumption.
[0004] In view of this, the present invention is proposed. Summary of the Invention
[0005] The purpose of this invention is to provide a method for preparing a sulfide electrolyte layer, which helps to simplify the solid-state battery manufacturing process.
[0006] This invention is implemented as follows:
[0007] In a first aspect, the present invention provides a method for preparing a sulfide electrolyte layer, specifically comprising the following steps:
[0008] A mixed slurry comprising raw material A, lithium salt, solvent and binder is coated onto an electrode to obtain an electrode with a mixed slurry coating; wherein raw material A is a sulfide electrolyte or a sulfide electrolyte precursor;
[0009] The electrode with the mixed slurry coating is dried to obtain a sulfide electrolyte layer attached to the electrode.
[0010] In an optional embodiment, the method for preparing the mixed slurry includes: adding a binder to a mixture of raw material A, lithium salt and solvent and stirring to obtain the mixed slurry.
[0011] In an optional embodiment, the stirring speed is 1000 rpm to 1500 rpm, the stirring time is 0.5 h to 5 h, and the stirring is carried out under argon protection.
[0012] In an optional embodiment, the mixture is ball-milled and filtered, then a binder is added, followed by stirring.
[0013] In an optional embodiment, the ball milling step is performed at a rotation speed of 1000 rpm to 2000 rpm and for a ball milling time of 0.5 h to 5 h.
[0014] In an optional embodiment, the mass ratio of raw material A to lithium salt in the mixed slurry is 3:(0.9-1.1).
[0015] In an optional embodiment, the mass-to-volume ratio of raw material A to solvent in the mixed slurry is (58-62) g / L.
[0016] In an optional embodiment, the mass ratio of raw material A to adhesive is 60:(0.9-1.1).
[0017] In an optional embodiment, the filtration includes passing the ball-milled slurry through a 50-325 mesh sieve.
[0018] In an optional embodiment, the drying temperature is 90℃~150℃, and the drying time is 1h~5h.
[0019] The present invention has the following beneficial effects:
[0020] In this invention, the preparation and coating processes of sulfide electrolytes are coupled together. The preparation and modification of the solid sulfide electrolyte layer are completed simultaneously using the electrode drying process. Repeated desolvation is not required, and the electrolyte is entirely in liquid or slurry during the process. Material preparation in a glove box is not necessary, which is more conducive to material transfer and transportation. This greatly reduces the difficulty and cost of completely isolating powder materials from water and oxygen. This method greatly shortens the preparation process and energy consumption, effectively reducing production costs. The method has a short production process, high process flexibility, and is more conducive to industrialization. Attached Figure Description
[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0022] Figure 1 This is a flowchart of Example 1;
[0023] Figure 2 This is a flowchart of Example 2;
[0024] Figure 3 This is the flowchart for Comparative Example 1. Detailed Implementation
[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.
[0026] This invention provides a method for preparing a sulfide electrolyte layer, specifically including the following steps:
[0027] A mixed slurry comprising raw material A, lithium salt, solvent and binder is coated onto an electrode to obtain an electrode with a mixed slurry coating; wherein raw material A is a sulfide electrolyte or a sulfide electrolyte precursor;
[0028] The electrode with the mixed slurry coating is dried to obtain a sulfide electrolyte layer attached to the electrode.
[0029] In this embodiment, the liquid-phase preparation of sulfide electrolytes and the coating process of sulfide electrolytes are coupled. The preparation and modification of the sulfide solid electrolyte layer are completed simultaneously using the electrode drying process. On the one hand, repeated desolvation is eliminated, which helps reduce energy consumption and simplify the process. On the other hand, except for the batching, the electrolyte is in liquid or slurry throughout the process, eliminating the need for material preparation in a glove box. This facilitates material transport and transfer, and ensures complete isolation of the powder material from water and oxygen, thereby improving the convenience of process implementation and further reducing costs. In summary, this method greatly reduces the preparation process and energy consumption, effectively lowers production costs, and features a short production process and high process flexibility, making it more conducive to industrialization.
[0030] In this embodiment, the sulfide electrolyte precursor may include Li2S and P2S5, and the molar ratio of Li2S to P2S5 may be (65-75):(25-35); the lithium salt may be selected from at least one of lithium chloride, lithium bromide, lithium iodide, lithium nitride, lithium carbide and lithium fluoride; the solvent may be selected from at least one of ethanol, butyl acetate, n-hexane and N-methylpyrrolidone; the binder may be selected from polyvinylidene fluoride (PVDF) and styrene-butadiene rubber (SBR).
[0031] In this embodiment, the coating method can be selected from roller coating, spray coating, slot coating, etc.; when the mixing of materials is involved in the preparation of the mixed slurry, the mixing method can be selected from the following mixing methods or a combination of mixing methods:
[0032] ① Emulsification;
[0033] ② Stirring + emulsification;
[0034] ③ Stirring + ball milling;
[0035] ④ Emulsification + ball milling;
[0036] ⑤ Stirring + ball milling + emulsification.
[0037] In an optional embodiment, the method for preparing the mixed slurry includes: adding a binder to a mixture of raw material A, lithium salt and solvent and stirring to obtain the mixed slurry.
[0038] In the process of preparing mixed slurry, in order to avoid the difficulty of stirring due to high viscosity, the other components except the binder are mixed evenly first, and then the binder is added, which is more conducive to improving efficiency.
[0039] In an optional embodiment, the stirring speed is 1000 rpm to 1500 rpm, the stirring time is 0.5 h to 5 h, and the stirring is carried out under argon protection.
[0040] Specifically, the stirring speed can be any value between 1000 rpm, 1100 rpm, 1200 rpm, 1300 rpm, 1400 rpm, 1500 rpm, or 1000 rpm to 1500 rpm, and the stirring time can be any value between 0.5 h, 1 h, 2 h, 3 h, 4 h, 5 h, or 0.5 h to 5 h.
[0041] Ensuring sufficient stirring speed and time helps improve the uniformity of the mixed slurry. At the same time, the stirring process is carried out under argon protection, which can prevent the material from failing after contact with air.
[0042] In an optional embodiment, the mixture is ball-milled and filtered, then a binder is added, followed by stirring.
[0043] Ball milling and filtration are beneficial for obtaining a fine and uniform mixture, which in turn facilitates the uniform dispersion of the mixed slurry on the electrode. At the same time, if the raw material A is a sulfide electrolyte precursor, the sulfide electrolyte precursor will also be converted into sulfide electrolyte during the ball milling process. Compared with the conversion of sulfide electrolyte precursor to sulfide electrolyte during drying, this is more conducive to the preparation of high-performance sulfide electrolyte.
[0044] In an optional embodiment, the ball milling step is performed at a speed of 1000 rpm to 2000 rpm and for a time of 0.5 h to 5 h. Ball milling can reduce the particle size and facilitate the uniform dispersion of each component in the mixture.
[0045] Specifically, the ball milling speed can be any value between 1000 rpm, 1100 rpm, 1200 rpm, 1300 rpm, 1400 rpm, 1500 rpm, 1600 rpm, 1700 rpm, 1800 rpm, 1900 rpm, 2000 rpm or 1000 rpm to 2000 rpm, and the ball milling time can be any value between 0.5 h, 1 h, 2 h, 3 h, 4 h, 5 h or 0.5 h to 5 h.
[0046] In an optional embodiment, the mass ratio of raw material A to lithium salt in the mixed slurry is 3:(0.9-1.1), specifically any value between 3:0.9, 3:1, 3:1.1 or 3:(0.9-1.1).
[0047] In an optional embodiment, the mass-to-volume ratio of raw material A to solvent in the mixed slurry is (58-62) g / L, specifically any value between 58, 59, 60, 61, 62 or (58-62) g / L.
[0048] In an optional embodiment, the mass ratio of raw material A to adhesive is 60:(0.9-1.1), specifically any value between 60:0.9, 60:1, 60:1.1 or 60:(0.9-1.1).
[0049] In an optional embodiment, the filtration includes passing the ball-milled slurry through a sieve with a mesh size of 50 to 325. Specifically, the mesh size can be any value between 50, 100, 150, 200, 250, 300, 325, or 50 to 325.
[0050] In an optional embodiment, the drying temperature is 90℃~150℃, and the drying time is 1h~5h.
[0051] Specifically, the drying temperature can be any value between 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃ or 90℃~150℃, and the drying time can be any value between 1h, 2h, 3h, 4h, 5h or 1h~5h.
[0052] During the drying process, solvent removal occurs. When raw material A is a sulfide electrolyte precursor and raw material A has not been ball-milled, the drying step is also accompanied by the conversion of the sulfide electrolyte precursor into the sulfide electrolyte.
[0053] The features and performance of the present invention will be further described in detail below with reference to embodiments.
[0054] Example 1:
[0055] A method for preparing a sulfide electrolyte layer is provided, such as... Figure 1 As shown, the specific steps include:
[0056] Weigh 60.0g of LPS precursor (Li2S and P2S5 in a molar ratio of 75:25), 20.0g of LiI, and 1.0g of SBR (styrene-butadiene rubber) binder, and add them to a mixing tank containing 1000ml of butyl acetate. Stir for 4 hours at 25°C and 2000rpm under 99.999% argon protection.
[0057] After homogenization, the slurry is uniformly coated onto the positive and negative electrode sheets using spraying / roller coating. It is then dried at 130℃ for 2 hours to obtain a sulfide electrolyte layer attached to the electrode sheets. The ionic conductivity of the sulfide electrolyte layer reaches 1.0 × 10⁻⁶. -3 Sulfide solid electrolyte with S / cm.
[0058] Example 2:
[0059] This embodiment provides a method for preparing a sulfide electrolyte layer, such as... Figure 2 As shown, the specific steps include:
[0060] Weigh 60.0g of LPS precursor (Li2S and P2S5 in a molar ratio of 75:25) and 20.0g of LiI, add them to 1000ml of butyl acetate, and use a ball mill at room temperature and a ball milling speed of 2000rpm for 2h under 99.999% argon protection. The ball-milled slurry is then sieved through a 50-mesh sieve to obtain a fine and uniform electrolyte slurry.
[0061] Add 1.0g of SBR (styrene-butadiene rubber) binder to the slurry after sieving, and stir for 4 hours at 25°C and 2000rpm under 99.999% argon protection.
[0062] After homogenization, the slurry is uniformly coated onto the positive and negative electrode sheets using spraying / roller coating. It is then dried at 130℃ for 2 hours to obtain a sulfide electrolyte layer attached to the electrode sheets. The ionic conductivity of the sulfide electrolyte layer reaches 1.0 × 10⁻⁶. -3 Sulfide solid electrolyte with S / cm.
[0063] Comparative Example 1
[0064] This comparative example provides a method for preparing a sulfide electrolyte layer, such as... Figure 3 As shown, the specific steps include:
[0065] Process 1: Solid Electrolyte Preparation
[0066] The synthesized LPS precursor (Li2S and P2S5 in a molar ratio of 75:25) and 20g of LiI were added to 1000ml of butyl acetate solvent. The mixture was ball-milled at 500rpm for 120min. After ball milling, the reaction slurry was dried to a powder with a solid content greater than 95%. Then, it was heated and complexed at 150℃ for 2h to form a lithium iodide and ethyl lithium complex coating layer on the surface of the solid electrolyte particles, thus obtaining the modified solid electrolyte material.
[0067] Step 2: Preparation of solid electrolyte slurry
[0068] The solid electrolyte powder was sealed and stored in high-purity argon gas and transferred to the battery production end. In a glove box isolated from water and oxygen, the prepared sulfide electrolyte, polyvinylpyrrolidone, and polymer ion conductor were added to an N,N-dimethylacetamide solution in a ratio of 58:3.5:38.5. The mixture was homogenized at 2000 rpm for 60 minutes to obtain a composite electrolyte slurry.
[0069] Step 3: Electrode Preparation
[0070] The composite electrolyte slurry was uniformly coated onto the electrode of a lithium-ion battery and dried at 150°C to obtain a conductivity ≥1×10⁻⁶. -3 Composite solid electrolyte with S / cm.
[0071] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for preparing a sulfide electrolyte layer, characterized in that, Specifically, the following steps are included: A mixed slurry comprising raw material A, lithium salt, solvent and binder is coated onto an electrode to obtain an electrode with a mixed slurry coating; wherein raw material A is a sulfide electrolyte or a sulfide electrolyte precursor; The electrode with the mixed slurry coating is dried to obtain a sulfide electrolyte layer attached to the electrode.
2. The method for preparing the sulfide electrolyte layer according to claim 1, characterized in that, The method for preparing the mixed slurry includes: adding a binder to a mixture of raw material A, lithium salt and solvent and stirring to obtain the mixed slurry.
3. The method for preparing the sulfide electrolyte layer according to claim 2, characterized in that, The stirring speed is 1000 rpm to 1500 rpm, the stirring time is 0.5 h to 5 h, and the stirring is carried out under argon protection.
4. The method for preparing the sulfide electrolyte layer according to claim 2, characterized in that, After ball milling and filtering the mixture, a binder is added, followed by stirring.
5. The method for preparing the sulfide electrolyte layer according to claim 4, characterized in that, The ball milling step is performed at a speed of 1000 rpm to 2000 rpm for a time of 0.5 h to 5 h.
6. The method for preparing the sulfide electrolyte layer according to claim 1, characterized in that, The mass ratio of raw material A to lithium salt in the mixed slurry is 3:(0.9-1.1).
7. The method for preparing the sulfide electrolyte layer according to claim 1, characterized in that, In the mixed slurry, the mass-volume ratio of raw material A to solvent is (58-62) g / L.
8. The method for preparing the sulfide electrolyte layer according to claim 1, characterized in that, The mass ratio of raw material A to adhesive is 60:(0.9-1.1).
9. The method for preparing the sulfide electrolyte layer according to claim 4, characterized in that, The filtration process includes passing the ball-milled slurry through a 50-325 mesh sieve.
10. The method for preparing the sulfide electrolyte layer according to claim 1, characterized in that, The drying temperature is 90℃~150℃, and the drying time is 1h~5h.