Method and apparatus for preparing composite electrode structures for all-solid-state batteries

Abstract

This application provides a method and apparatus for preparing a composite electrode structure for an all-solid-state battery, relating to the field of solid-state batteries. The method for preparing the composite electrode structure includes: pre-pressing an electrode sheet to obtain a pre-pressed electrode sheet; imprinting the pre-pressed electrode sheet using a textured roller to obtain a patterned electrode sheet with a patterned surface, the patterned surface comprising patterned and unpatterned regions, the thickness of the patterned region differing from the thickness of the unpatterned region; and combining the patterned electrode sheet with a solid electrolyte membrane, performing multi-stage roller transfer to obtain the composite electrode structure. This application enhances the bonding force with the solid electrolyte membrane by preparing an uneven pattern on the electrode sheet surface, thereby improving the stability of the composite electrode structure. The patterned electrode sheet combined with the electrolyte membrane can form ion channels, which is beneficial for improving the electrochemical performance of the battery.

Description

Technical Field

[0001] This application relates to the field of solid-state batteries, and in particular to a method and apparatus for preparing a composite electrode structure for an all-solid-state battery. Background Technology

[0002] Solid-state batteries, as a high-performance and highly safe new battery technology, have received widespread attention in recent years. Their core advantage lies in using a solid electrolyte to replace the traditional liquid electrolyte, thereby significantly improving the battery's energy density and safety. However, the composite process of the negative electrode and solid electrolyte has always been one of the technical bottlenecks in the manufacturing of solid-state batteries.

[0003] Currently, the composite of solid-state battery anode and solid electrolyte membrane is mainly achieved through the following two methods: single-stage constant voltage transfer and wet slurry transfer-in-situ curing.

[0004] Single-stage constant-pressure transfer printing typically uses two pressure rollers or a hot platen to apply pressure to the negative electrode and electrolyte in a single step. Single-stage pressure has the problem of uniform pressure, failing to simultaneously address both "venting" and "densification" requirements, resulting in high interfacial porosity. Furthermore, single-stage constant-pressure transfer printing is prone to bubbles, cracks, edge defects, and insufficient peel strength, leading to low peel strength, increased internal resistance, and reduced cycle life.

[0005] The wet paste transfer-in-situ curing method involves first floating the negative electrode film onto a sulfide wet paste, and then curing it through hot pressing. This method applies a single-stage pressure during hot pressing, which cannot effectively degas the material, making it difficult to completely eliminate micropores. Furthermore, the solids content of the wet paste needs to be strictly matched, making the process complex. Summary of the Invention

[0006] The purpose of this application is to provide a method and apparatus for preparing a composite electrode structure for an all-solid-state battery, so as to solve the above-mentioned problems.

[0007] To achieve the above objectives, this application adopts the following technical solution:

[0008] A method for preparing a composite electrode structure for an all-solid-state battery, comprising:

[0009] The electrode sheets are pre-pressed to obtain pre-pressed electrode sheets;

[0010] The pre-pressed electrode sheet is pressed using a pressure roller with a textured surface to obtain an electrode sheet with a patterned surface. The patterned electrode sheet includes a patterned area and a non-patterned area, and the thickness of the patterned area is different from the thickness of the non-patterned area.

[0011] The patterned electrode sheet on the surface is combined with a solid electrolyte membrane and subjected to multi-stage roll transfer printing to obtain a composite electrode structure, wherein the number of roll transfer printing cycles is greater than or equal to 2.

[0012] In some embodiments, the pressure of adjacent roller transfer stages in the multi-stage roller transfer is different.

[0013] According to embodiments of this application, the electrode sheet includes a positive electrode sheet or a negative electrode sheet.

[0014] According to an embodiment of this application, the compaction density of the pre-compressed electrode sheet is 1.1~1.6 g / cm³. 3 ;

[0015] And / or, the linear pressure of the embossing is 0.5-1 kN / m, and the embossing speed is 10-50 m / min.

[0016] According to an embodiment of this application, the number of roller transfers is 3, and the multi-stage roller transfer includes pre-press transfer, main press transfer, and fine press transfer;

[0017] The pressure of the pre-press transfer is 0.1~0.5 MPa, and the temperature of the pre-press transfer is 20~80 ℃;

[0018] The pressure of the main pressure transfer is 0.3~0.8 MPa, and the temperature of the main pressure transfer is 20~90℃;

[0019] The pressure of the precision transfer is 0.40~2.0 MPa, and the temperature of the precision transfer is 20~90℃.

[0020] According to an embodiment of this application, after each stage of roller transfer printing is completed, the thickness of the composite structure is detected, and the control amount of the next stage of roller transfer printing is adjusted based on the deviation between the detected thickness of the composite structure and the set thickness.

[0021] The adjustment of the pressure for the roller transfer includes:

[0022] When the detected thickness is greater than the set thickness, increase the pressure of the next stage of roller transfer and / or decrease the distance between the pressure rollers;

[0023] When the detected thickness is less than the set thickness, reduce the pressure of the next stage of roller transfer and / or increase the distance between the pressure rollers.

[0024] According to an embodiment of this application, the method further includes: using a laser thickness gauge to detect the structure of the composite structure;

[0025] And / or, use the MPC controller to calculate the control quantity for the next stage of roller transfer printing.

[0026] This application also provides an apparatus for fabricating a composite electrode structure for an all-solid-state battery. The apparatus is used to perform the fabrication method for the composite electrode structure of an all-solid-state battery as described above. The apparatus includes:

[0027] A pre-pressing roller is used to pre-press the electrode sheet to obtain a pre-pressed electrode sheet;

[0028] An anilox roller, the surface of which has a texture, is disposed on the conveying path of the pre-pressed electrode sheet and is used to form a pattern on the surface of the pre-pressed electrode sheet to obtain an electrode sheet with a patterned surface.

[0029] A gradient pressure roller assembly is positioned on the conveying path of the patterned electrode sheet on the surface, and is used to combine the patterned electrode sheet with a solid electrolyte membrane to obtain a composite electrode structure.

[0030] According to an embodiment of this application, the surface of the anilox roller has an array of textures, the texture being pits;

[0031] The depth of the pit is 2-5 μm, and the distance between adjacent pits is 50-100 μm;

[0032] And / or, the shape of the recess includes at least one of a triangle, a square, a parallelogram, and a rectangle.

[0033] According to an embodiment of this application, the gradient pressure roller group includes three sets of servo pressure rollers, each set of servo pressure rollers has a built-in piezoelectric ceramic actuator, and each set of servo pressure rollers can be independently pressure adjusted.

[0034] According to embodiments of this application, the device further includes a laser thickness gauge and an MPC controller.

[0035] Compared with the prior art, the beneficial effects of this application include:

[0036] This application enhances the adhesion between the electrode sheet and the solid electrolyte membrane by preparing an uneven pattern on the surface of the electrode sheet, thereby improving the stability of the composite electrode structure. Compared with a flat electrode sheet without a pattern, the peel strength of this application is increased by more than 40%. When the patterned electrode sheet of this application is combined with the electrolyte membrane, it can form ion channels, which is beneficial to improving the electrochemical performance of the battery. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.

[0038] Figure 1 This is a flowchart illustrating the fabrication method of the composite electrode structure for the all-solid-state battery of this application. Detailed Implementation

[0039] As used in this article:

[0040] "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0041] The conjunction "composed of..." excludes any unspecified elements, steps, or components. If used in a claim, this phrase makes the claim closed, excluding materials other than those described, except for associated conventional impurities. When the phrase "composed of..." appears in a clause of the body of a claim rather than immediately following it, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0042] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1–5” is disclosed, the described range should be interpreted as including ranges “1–4”, “1–3”, “1–2”, “1–2 and 4–5”, “1–3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0043] In these embodiments, unless otherwise specified, the portions and percentages are all by weight.

[0044] "Parts by mass" refers to the basic unit of measurement that expresses the mass ratio of multiple components. One part can represent any unit mass, such as 1g or 2.689g. If we say that component A has "a" parts by mass and component B has "b" parts by mass, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it can mean that the mass of component A is aK and the mass of component B is bK (where K is any number representing a multiplier). It is important to understand that, unlike parts by mass, the sum of the mass parts of all components is not limited to 100 parts.

[0045] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0046] A method for fabricating a composite electrode structure for an all-solid-state battery, referenced Figure 1 ,include:

[0047] The electrode sheets are pre-pressed to obtain pre-pressed electrode sheets;

[0048] The pre-pressed electrode sheet is pressed using a pressure roller with a textured surface to obtain an electrode sheet with a patterned surface. The patterned electrode sheet includes a patterned area and a non-patterned area, and the thickness of the patterned area is different from the thickness of the non-patterned area.

[0049] The patterned electrode sheet on the surface is combined with a solid electrolyte membrane and subjected to multi-stage roll transfer printing to obtain a composite electrode structure. The number of roll transfer printing stages is greater than or equal to 2, and the pressure of adjacent roll transfer printing stages is different.

[0050] According to embodiments of this application, the electrode sheet includes a positive electrode sheet or a negative electrode sheet.

[0051] When the electrode sheet is a negative electrode sheet, the negative electrode sheet includes a negative current collector and a negative active layer located on the negative current collector, and the negative active layer is made of negative electrode slurry;

[0052] In some embodiments, the thickness of the negative electrode active layer is 30-50 μm.

[0053] The solid content of the negative electrode slurry is 40%~50%;

[0054] The negative electrode active layer material comprises 60 wt% to 70 wt% silicon, 10 wt% to 20 wt% graphite, 5 wt% to 10 wt% conductive agent, 4 wt% to 7 wt% binder, and 1 wt% to 5 wt% functional additives. The silicon material is nano-silicon powder with a D50 particle size of 50 nm to 150 nm. The conductive agent includes conductive carbon black and carbon nanotubes, the binder includes sodium carboxymethyl cellulose and lithium polyacrylate, and the functional additive is hollow silica microspheres.

[0055] According to an embodiment of this application, the compaction density of the pre-compressed electrode sheet is 1.1~1.6 g / cm³. 3 ;

[0056] For example, the compaction density of the pre-compressed electrode sheet is 1.1 g / cm³. 3 1.2 g / cm 3 1.3 g / cm 31.4 g / cm 3 1.5 g / cm 3 1.6 g / cm 3 Or 1.1~1.6 g / cm 3 Any value between.

[0057] And / or, the linear pressure of the embossing is 0.5-1 kN / m, and the embossing speed is 10-50 m / min.

[0058] For example, the linear pressure of the embossing is 0.5 kN / m, 0.6 kN / m, 0.7 kN / m, 0.8 kN / m, 0.9 kN / m, 1 kN / m or any value between 0.5 and 1 kN / m, and the embossing speed is 10 m / min, 20 m / min, 30 m / min, 40 m / min, 50 m / min or any value between 10 and 50 m / min.

[0059] According to an embodiment of this application, the number of roller transfers is 3, and the multi-stage roller transfer includes pre-press transfer, main press transfer, and fine press transfer;

[0060] The pressure of the pre-press transfer is 0.1~0.5 MPa, and the temperature of the pre-press transfer is 20~80 ℃; it serves to exhaust air.

[0061] For example, the pressure for pre-press transfer is 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa or any value between 0.1 and 0.5 MPa, and the temperature for pre-press transfer is 20 ℃, 30 ℃, 40 ℃, 50 ℃, 60 ℃, 70 ℃, 80 ℃ or any value between 20 and 80 ℃.

[0062] The pressure of the main pressure transfer is 0.3~0.8 MPa, and the temperature of the main pressure transfer is 20~90℃; it plays a densifying role.

[0063] For example, the pressure of the main pressure transfer is 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa or any value between 0.3 and 0.8 MPa, and the temperature of the main pressure transfer is 20℃, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃ or any value between 20 and 90℃.

[0064] The pressure of the precision transfer is 0.40~2.0 MPa, and the temperature of the precision transfer is 20~90℃. It serves a leveling function.

[0065] For example, the pressure for precision transfer is 0.40 MPa, 0.6 MPa, 0.8 MPa, 1.0 MPa, 1.2 MPa, 1.4 MPa, 1.6 MPa, 1.8 MPa, 2.0 MPa, or any value between 0.40 and 2.0 MPa, and the temperature for precision transfer is 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, or any value between 20 and 90°C.

[0066] In existing composite methods for solid-state batteries, the thickness fluctuations cannot be corrected in real time, resulting in high defect density.

[0067] To improve the shortcomings of existing methods that cannot correct thickness fluctuations in real time, in some embodiments of this application, after each stage of roll transfer is completed, the thickness of the composite structure is detected, and the control amount of the next stage of roll transfer is adjusted according to the deviation between the detected thickness of the composite structure and the set thickness.

[0068] The adjustment of the pressure for the roller transfer includes:

[0069] When the detected thickness is greater than the set thickness, increase the pressure of the next stage of roller transfer and / or decrease the distance between the pressure rollers;

[0070] When the detected thickness is less than the set thickness, reduce the pressure of the next stage of roller transfer and / or increase the distance between the pressure rollers.

[0071] According to an embodiment of this application, the method further includes: using a laser thickness gauge to detect the structure of the composite structure;

[0072] And / or, use the MPC controller to calculate the control quantity for the next stage of roller transfer printing.

[0073] The MPC controller adjusts the piezoelectric actuator every 1ms to achieve closed-loop control. The MPC control logic is as follows: during the continuous transfer and lamination process, the thickness after transfer is detected by a laser thickness gauge, and the difference between the current material thickness and the set target thickness is calculated. Using this difference as input, the pressure and / or roller gap of the transfer equipment are dynamically adjusted to complete the closed-loop control of the composite electrode thickness.

[0074] MPC controller: prediction step size k=5, smoothing factor λ=0.2, objective function minΣ[e(t+k)] 2 +λ·ΔGap 2In this equation, e(t+k) represents the difference between the thickness measured by the laser thickness gauge at time t+k and the target thickness; ΔGap represents the roll gap value that needs to be adjusted; λ is a weighting coefficient used to balance the relative importance of the deviation and adjustment terms, and is adjusted based on actual experimental verification to ensure the model meets the requirements; k is the number of prediction steps of the model, which can be adjusted according to the actual situation. The purpose of minimizing the objective function is to minimize the thickness deviation value while also minimizing the dynamic adjustment process, because large adjustments in continuous production will lead to poorer stability. As the parameters above indicate, the thickness deviation value and the dynamic adjustment value of the equipment are minimized at the five consecutive step times t, t+1, t+2, t+3, t+4, and t+5.

[0075] In some embodiments, the method further includes a step of peeling off the electrolyte membrane substrate; this step may be omitted if the electrolyte membrane is a self-supporting membrane.

[0076] This application reduces the porosity of the electrode / electrolyte membrane composite to ≤2% and increases the anode / electrolyte peel strength to ≥6N / cm.

[0077] This application also provides an apparatus for fabricating a composite electrode structure for an all-solid-state battery. The apparatus is used to perform the fabrication method for the composite electrode structure of an all-solid-state battery as described above. The apparatus includes:

[0078] A pre-pressing roller is used to pre-press the electrode sheet to obtain a pre-pressed electrode sheet;

[0079] An anilox roller, the surface of which has a texture, is disposed on the conveying path of the pre-pressed electrode sheet and is used to form a pattern on the surface of the pre-pressed electrode sheet to obtain an electrode sheet with a patterned surface.

[0080] A gradient pressure roller assembly is positioned on the conveying path of the patterned electrode sheet on the surface, and is used to combine the patterned electrode sheet with a solid electrolyte membrane to obtain a composite electrode structure.

[0081] According to an embodiment of this application, the surface of the anilox roller has an array of textures, the texture being pits;

[0082] The depth of the pit is 2-5 μm, and the distance between adjacent pits is 50-100 μm;

[0083] For example, the depth of the pit is any value between 2μm, 3μm, 4μm, 5μm or 2-5μm, and the distance between adjacent pits is any value between 50μm, 60μm, 70μm, 80μm, 90μm, 100μm or 50-100μm.

[0084] And / or, the shape of the recess includes at least one of a triangle, a square, a parallelogram, and a rectangle.

[0085] According to an embodiment of this application, the gradient pressure roller group includes three sets of servo pressure rollers, each set of servo pressure rollers has a built-in piezoelectric ceramic actuator, and each set of servo pressure rollers can be independently pressure adjusted.

[0086] According to embodiments of this application, the device further includes a laser thickness gauge and an MPC controller.

[0087] The implementation schemes of this application will be described in detail below with reference to specific embodiments. However, those skilled in the art will understand that the following embodiments are only for illustrating this application and should not be regarded as limiting the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0088] Example 1

[0089] Example 1 provides an apparatus for fabricating a composite electrode structure for an all-solid-state battery. The apparatus includes:

[0090] The pre-roller is used to pre-press the negative electrode sheet to obtain a pre-pressed negative electrode sheet; the diameter of the pre-roller is 200mm, the surface is mirror-finished, and Ra≤30 nm.

[0091] The anilox roller has a textured surface and is positioned on the conveying path of the pre-pressed negative electrode sheet. It is used to form a pattern on the surface of the pre-pressed negative electrode sheet to obtain a negative electrode sheet with a patterned surface. The anilox roller has a diameter of 200 mm and an array of pits on its surface. The pits are 2 μm deep and 100 μm apart. The pits are triangular in shape.

[0092] The gradient pressure roller assembly is positioned on the conveying path of the negative electrode sheet with a patterned surface, and is used to combine the patterned negative electrode sheet with a solid electrolyte membrane to obtain a composite electrode structure. The gradient pressure roller assembly includes three sets of servo pressure rollers, each with a built-in piezoelectric ceramic actuator, and each servo pressure roller is independently pressure-adjusted with a resolution ≤0.01MPa.

[0093] Laser thickness gauge, 5-point laser thickness gauge head, 905nm wavelength, sampling frequency ≥1kHz, accuracy ±0.5μm. The laser thickness gauge is used to detect the thickness of composite structures after roll transfer printing.

[0094] MPC controller, prediction step size k=5, smoothing factor λ=0.2, objective function min Σ[e(t+k)] 2 +λ·ΔGap2 The MPC controller outputs control parameters for the next stage of roll transfer printing based on the deviation between the detected thickness and the set thickness. The MPC controller adjusts the piezoelectric actuator every 1ms to achieve a closed loop.

[0095] Methods for preparing composite electrode structures for all-solid-state batteries include:

[0096] Step A: Preparation of the negative electrode sheet

[0097] A negative electrode slurry with a solid content of 45% was prepared with water according to the following formula and coated onto a negative electrode current collector. After drying, a negative electrode active layer with a thickness of 40 μm was formed on the negative electrode current collector, thus obtaining a negative electrode sheet.

[0098] Nano-silicon powder (D50≈100 nm, Si≥99.9%) 65 wt%

[0099] Artificial graphite (D50 ≈ 8 μm) 20 wt%

[0100] 6 wt% conductive carbon black

[0101] Carbon nanotubes (outer diameter 10-20 nm) 2 wt%

[0102] Sodium carboxymethyl cellulose (120 kDa) 2.0 wt%

[0103] Lithium polyacrylate (Mw≈250 kDa) 3.0 wt%

[0104] Hollow SiO2 microspheres (particle size 200 nm, wall thickness 20 nm) 2.0 wt%

[0105] Step B: Negative electrode pre-rolling

[0106] The negative electrode sheet obtained in step A is pre-rolled at a pressure of 0.20 MPa to reduce its compaction density to 1.2 g / cm³. 3 .

[0107] Step C: Texture Roller Pressing

[0108] Using a textured steel roller (dimples 2μm deep, 100μm spacing, equilateral triangle pattern), with a linear pressing of 0.8 kN / m, a pattern is rolled onto the surface of the negative electrode sheet. The resulting negative electrode sheet includes a patterned area and an unpatterned area, with the thickness of the patterned area being different from that of the unpatterned area.

[0109] Step D: The sulfide solid electrolyte powder and binder PAA are dispersed in the solvent dimethylformamide to form an electrolyte suspension. The slurry is then coated onto aluminum foil and dried to form a solid electrolyte membrane with a substrate. The patterned electrode sheet obtained in Step C is then laminated with the solid electrolyte membrane and subjected to multi-stage roll transfer printing. The multi-stage roll transfer printing is performed three times, with different pressures for each stage. The multi-stage roll transfer printing includes pre-press transfer printing, main press transfer printing, and fine press transfer printing.

[0110] The pressure for pre-press transfer is 0.20 MPa, and the temperature for pre-press transfer is 80℃; the pressure for main pressure transfer is 0.35 MPa, and the temperature for main pressure transfer is 85℃; the pressure for fine pressure transfer is 0.50 MPa, and the temperature for fine pressure transfer is 90℃.

[0111] Step E: Peel off the electrolyte membrane substrate to form a negative electrode / electrolyte membrane composite.

[0112] Example 2

[0113] The difference between Example 2 and Example 1 is that the conditions for multi-stage roller transfer in step D are as follows: the pressure of pre-press transfer is 0.25 MPa, and the temperature of pre-press transfer is 80°C; the pressure of main press transfer is 0.4 MPa, and the temperature of main press transfer is 85°C; the pressure of fine press transfer is 0.55 MPa, and the temperature of fine press transfer is 90°C. The rest is the same as in Example 1.

[0114] Comparative Example 1

[0115] The difference between Comparative Example 1 and Example 1 is that step C uses a smooth roller press for pressing, resulting in a uniform thickness of the negative electrode sheet after pressing in step C, without any uneven patterns. Everything else is the same as in Example 1.

[0116] Comparative Example 2

[0117] The difference between Comparative Example 2 and Example 1 is that step D involves single-stage roller transfer printing at a pressure of 0.5 MPa and a temperature of 90°C. Everything else is the same as in Example 1.

[0118] The performance of the composite electrode structures prepared in Examples 1-2 and Comparative Examples 1-2 was tested.

[0119] The testing methods included: testing the porosity of the composite electrode structure using the BET (nitrogen adsorption) method; measuring the peel strength of the composite electrode structure using a peel strength tester; and measuring the surface finish Ra of the composite electrode structure using a spectroscopic confocal microscope.

[0120] The test results are shown in Table 1.

[0121] Table 1

[0122]

[0123] As can be seen from Table 1, compared with Comparative Examples 1-2, the composite electrode structures of Examples 1-2 have lower porosity and higher peel strength, which is beneficial to improving electrochemical performance.

[0124] The composite electrode structures of Examples 1-2 and Comparative Examples 1-2 were assembled into an all-solid-state battery. The battery assembly method included: die cutting, cutting the composite film in Examples 1-2 and Comparative Examples 1-2 into 8*10mm electrode sheets respectively; stacking, stacking with 6*8mm positive electrode sheets; welding, ultrasonically welding the positive and negative electrode tabs; encapsulation, vacuum encapsulating the electrode core with the welded tabs in an aluminum-plastic film; isostatic pressing, isostatic pressing the cell; and formation testing, charging and discharging testing the cell to test its electrical performance.

[0125] The electrochemical performance of the all-solid-state battery was tested, including its voltage resistance, initial efficiency, and rate performance. The test results are shown in Table 2.

[0126] Table 2. Comparison of electrochemical performance between Examples 1-2 and Comparative Examples 1-2

[0127]

[0128] As shown in Table 2, the internal resistance of Examples 1-2 is lower than that of Comparative Examples 1-2, the rate performance of Examples 1-2 is better than that of Comparative Examples 1-2, Examples 1-2 has a higher initial efficiency, and the overall electrochemical performance of Examples 1-2 is better than that of Comparative Examples 1-2. This indicates that the battery cells assembled by combining negative electrode mesh patterning with multi-stage roll transfer printing have significant advantages in terms of internal resistance and rate performance.

[0129] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0130] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the foregoing claims, any of the claimed embodiments can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. A method for preparing a composite electrode structure for an all-solid-state battery, characterized in that, include: The electrode sheets are pre-pressed to obtain pre-pressed electrode sheets; The pre-pressed electrode sheet is pressed using a pressure roller with a textured surface to obtain an electrode sheet with a patterned surface. The patterned electrode sheet includes a patterned area and a non-patterned area, and the thickness of the patterned area is different from the thickness of the non-patterned area. The patterned electrode sheet on the surface is combined with a solid electrolyte membrane and subjected to multi-stage roll transfer printing to obtain a composite electrode structure. The roll transfer printing is performed three times, and the multi-stage roll transfer printing includes pre-press transfer printing, main press transfer printing, and fine press transfer printing. The pressure of adjacent two stages of roll transfer printing is different. The pressure of the pre-press transfer is 0.1~0.5 MPa, and the temperature of the pre-press transfer is 70~80℃; The pressure of the main pressure transfer is 0.3~0.8 MPa, and the temperature of the main pressure transfer is 80~90℃; The pressure of the precision transfer is 0.40~2.0MPa, and the temperature of the precision transfer is 80~90℃.

2. The method for preparing the composite electrode structure of the all-solid-state battery according to claim 1, characterized in that, The electrode plates include positive electrode plates or negative electrode plates.

3. The method for preparing the composite electrode structure of the all-solid-state battery according to claim 1, characterized in that, The compaction density of the pre-compressed electrode sheet is 1.1~1.6 g / cm³. 3 ; And / or, the linear pressure of the embossing is 0.5-1 kN / m, and the embossing speed is 10-50 m / min.

4. The method for preparing the composite electrode structure of the all-solid-state battery according to any one of claims 1-3, characterized in that, After each stage of roller transfer is completed, the thickness of the composite structure is detected. Based on the deviation between the detected thickness and the set thickness, the control amount of the next stage of roller transfer is adjusted. Adjusting the control parameters for roller transfer printing includes: When the detected thickness is greater than the set thickness, increase the pressure of the next stage of roller transfer and / or decrease the distance between the pressure rollers; When the detected thickness is less than the set thickness, reduce the pressure of the next stage of roller transfer and / or increase the distance between the pressure rollers.

5. The method for preparing the composite electrode structure of the all-solid-state battery according to claim 4, characterized in that, The method further includes: using a laser thickness gauge to detect the thickness of the composite structure; And / or, use the MPC controller to calculate the control quantity for the next stage of roller transfer printing.

6. An apparatus for preparing a composite electrode structure for an all-solid-state battery, characterized in that, The apparatus for fabricating the composite electrode structure of the all-solid-state battery is used to perform the method for fabricating the composite electrode structure of the all-solid-state battery as described in any one of claims 1-5, wherein the fabrication apparatus comprises: A pre-pressing roller is used to pre-press the electrode sheet to obtain a pre-pressed electrode sheet; An anilox roller, the surface of which has a texture, is disposed on the conveying path of the pre-pressed electrode sheet and is used to form a pattern on the surface of the pre-pressed electrode sheet to obtain an electrode sheet with a patterned surface. A gradient pressure roller assembly is positioned on the conveying path of the patterned electrode sheet on the surface, and is used to combine the patterned electrode sheet with a solid electrolyte membrane to obtain a composite electrode structure.

7. The apparatus for preparing the composite electrode structure of an all-solid-state battery according to claim 6, characterized in that, The surface of the anilox roller has an array of textures, and the textures are pits; The depth of the pit is 2-5 μm, and the distance between adjacent pits is 50-100 μm; The shape of the pit includes at least one of triangle, parallelogram, and rectangle.

8. The apparatus for preparing the composite electrode structure of an all-solid-state battery according to claim 6, characterized in that, The gradient pressure roller group includes three sets of servo pressure rollers, each set of servo pressure rollers has a built-in piezoelectric ceramic actuator, and each set of servo pressure rollers can be independently pressure adjusted.

9. The apparatus for preparing the composite electrode structure of an all-solid-state battery according to any one of claims 6-8, characterized in that, The device also includes a laser thickness gauge and an MPC controller.

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