Solid-state battery assembly method and system

Abstract

The invention relates to a solid-state battery assembly method and system in the technical field of lithium battery production, and the method comprises the following steps: S1, coating electrolyte slurry on two sides of a film to form a composite film; s2, stacking the composite film, the positive plate and the negative plate in a crossed manner to form a lamination body; and S3, packaging the lamination body. The two sides of a diaphragm are coated with electrolyte slurry to form a composite diaphragm, and then the composite diaphragm, a positive plate and a negative plate are sequentially stacked in a crossed mode. The electrolyte slurry is coated on the surface of the diaphragm, and after the composite diaphragm and positive and negative pole pieces are stacked in a crossed manner, the electrolyte slurry is in contact with the pole pieces, so that the surfaces of the pole pieces can be infiltrated, the contact area of the electrolyte slurry and the pole pieces is increased, the infiltration speed is increased, and the infiltration uniformity of the pole pieces can be ensured; meanwhile, compared with a polymer electrolyte injection mode, the raw material cost is saved.

Description

Technical Field

[0001] This invention relates to the field of lithium battery production technology, and in particular to a solid-state battery assembly method and system. Background Technology

[0002] Solid-state batteries mainly consist of solid electrodes and a solid electrolyte, with the solid electrolyte positioned between the positive and negative solid electrodes. One of the biggest challenges in solid-state batteries is the solid-solid interface contact. The interface impedance between the solid electrolyte and the positive and negative electrode materials is high, resulting in low transmission efficiency and large internal resistance, which affects the battery's cycle performance and may cause localized overheating, posing certain safety hazards.

[0003] Existing technologies primarily improve interfacial impedance by injecting polymer electrolytes into the battery, allowing the polymer electrolyte to wet the electrode and solid electrolyte surfaces. Since a battery contains several stacked electrodes, current processes involve the electrolyte wetting from the electrode edges towards the center of the stack after injection. This not only results in excessively long wetting times but also easily leads to uneven wetting of the electrode surfaces. Furthermore, this electrolyte injection process requires injecting a large amount of polymer electrolyte into the battery to ensure that the electrolyte penetrates to the center of the stacked electrodes, significantly increasing raw material costs.

[0004] Therefore, a technical solution is urgently needed to solve the above problems. Summary of the Invention

[0005] To address the aforementioned problems, this invention discloses a solid-state battery assembly method and system. The technical solution of this invention is implemented as follows:

[0006] The first aspect of this invention discloses a method for preparing a solid-state battery, the method comprising the following steps:

[0007] S1. Coat both sides of the film with electrolyte slurry to form a composite film;

[0008] S2. The composite film is directly stacked with the positive and negative electrode sheets to form a stacked body;

[0009] S3. Encapsulate the stacked body.

[0010] Preferably, the freezing point range of the electrolyte slurry is -80℃ to -30℃, and the viscosity of the electrolyte slurry is η, where 70 < η < 1500 (mPa·s).

[0011] Preferably, in S1, the method of applying the electrolyte slurry onto the film includes any one of gravure roller forward coating, gravure roller reverse coating, and extrusion coating.

[0012] Preferably, in step S1, an electrolyte coating is simultaneously applied to both sides of the film, forming an electrolyte coating on both sides of the film simultaneously; the areal density of the electrolyte coating is 1.5 g / m³. 2 ~100g / m 2 .

[0013] Preferably, after S3, the process further includes placing the packaged stacked body in an environment of 20°C to 60°C.

[0014] Preferably, the preparation of a positive electrode and a negative electrode is included before step S2; wherein the method for preparing the positive electrode includes the following steps:

[0015] S11. Cut the positive electrode roll to form a positive electrode sheet;

[0016] S12. Inspect the positive electrode and remove defective positive electrode sheets;

[0017] The preparation method of the negative electrode includes the following steps:

[0018] S13. Cut the negative electrode roll to form a negative electrode sheet;

[0019] S14. Inspect the negative electrode and remove any defective negative electrode sheets.

[0020] The second aspect of the present invention discloses a solid-state battery preparation system. The assembly method disclosed in the first aspect of the present invention is carried out in the solid-state battery assembly system. The solid-state battery preparation system includes a thin film unwinding roller, a coating device, a first feeding device, a second feeding device, and a stacking device.

[0021] The film unwinding roller is used to unwind the film.

[0022] The coating device is located downstream of the film unwinding roller, and a set of coating devices is provided on both sides of the film for double-sided coating of electrolyte slurry on the film to generate a composite film.

[0023] The first feeding device transports the positive electrode sheet. The first feeding device is located on one side of the coating device and upstream of the stacking device.

[0024] The second feeding device is used to transport the negative electrode sheet. The second feeding device is located on the other side of the coating device and upstream of the stacking device.

[0025] The stacking device is used to receive positive electrode sheets, negative electrode sheets, and composite films, and to stack them.

[0026] Preferably, the coating apparatus includes a gravure roller, a scraper, and a material box;

[0027] The material box is located on one side of the gravure roller and contains electrolyte slurry. The gravure roller extends at least partially into the material box and carries out the electrolyte slurry by rotating. One end of the scraper faces the gravure roller and is used to scrape off excess electrolyte slurry from the gravure roller.

[0028] Preferably, the upstream of the first feeding device further includes a positive electrode preparation device for preparing positive electrode sheets;

[0029] The upstream of the second feeding device also includes a negative electrode preparation device, used to prepare negative electrode sheets.

[0030] Preferably, the stacking device includes a stacking stage, a first driving member, a platform, a displacement plate, and a second driving member;

[0031] Both the first driving unit and the stacking table are mounted on the displacement plate. The output end of the first driving unit is connected to the stacking table and is used to drive the stacking table to reciprocate between the output end of the first feeding device and the output end of the second feeding device.

[0032] The second driving component is mounted on the platform, and its output end is connected to the displacement plate. The second driving component is used to drive the displacement plate to move up and down.

[0033] The advantages of this invention are as follows:

[0034] This invention involves coating both sides of a separator with an electrolyte slurry to form a composite separator. The composite separator is then directly and alternately stacked with the positive and negative electrode sheets. By coating the separator surface with the electrolyte slurry, the electrolyte slurry comes into contact with the electrode sheets after the composite separator and the positive and negative electrode sheets are alternately stacked. This wets the electrode surface, increasing the contact area between the electrolyte slurry and the electrode sheets. This not only improves the wetting speed but also ensures uniform wetting of the electrode sheets. Furthermore, compared to injecting polymer electrolytes, it saves on raw material costs. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Identical parts are indicated by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, while the terms "bottom surface," "top surface," "inner," and "outer" refer to directions toward or away from the geometric center of a specific part, respectively.

[0037] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of the gravure roller reverse coating structure;

[0039] Figure 3 This is a schematic diagram of the coating structure for an extrusion die.

[0040] In the above figures, the figure numbers indicate the following:

[0041] 1. Film unwinding roller; 2. Coating device; 21. Gravure roller; 22. Scraper; 23. Extrusion die; 3. First feeding device; 31. First conveyor belt; 4. Second feeding device; 41. Second conveyor belt; 5. Stacking device; 51. Stacking table; 52. First driving component; 521. Motor; 522. Lead screw; 53. Platform; 54. Displacement plate; 55. Second driving component; 6. Positive electrode preparation device; 61. First unwinding roller; 62. First cutting assembly; 621. First electrode lug die-cutting structure; 622. First electrode cutting structure; 7. Detection assembly; 71. CCD detection device; 72. Third conveyor belt; 73. Abnormal clip; 74. Rejection claw; 8. Negative electrode preparation device; 81. Second unwinding roller; 82. Second cutting assembly; 821. Second electrode lug die-cutting structure; 822. Second electrode cutting structure. Detailed Implementation

[0042] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0043] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used in the detailed description is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0044] In the description of specific embodiments of the present invention, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present invention, "multiple" means two or more, unless otherwise explicitly defined.

[0045] In this invention, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this invention can be combined with other embodiments.

[0046] In the description of the embodiments of this invention, the term "and / or" is merely a description of the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this invention, the character " / " generally indicates that the preceding and following associated objects have an "or" relationship.

[0047] Throughout this invention, numerical values ​​represent approximate measures or limits of a range to cover minute deviations from a given value, as well as embodiments with approximately the mentioned value and embodiments with the exact mentioned value. Except for the working examples provided at the end of the detailed description, all numerical values ​​of parameters (e.g., quantities or conditions) in this specification (including the appended claims) should be understood to be modified in all cases by the term “about,” regardless of whether “about” actually appears before the numerical value. “About” indicates that the stated numerical value allows for some minor inaccuracy (somewhat close to the exact value; approximately or reasonably close to the value; almost). If the inaccuracy provided by “about” is not otherwise understood in this general sense in the art, then “about” as used in this invention at least indicates a variation that can be produced by common methods of measuring and using such a parameter. For example, “about” may include a variation less than or equal to 5%, optionally less than or equal to 4%, optionally less than or equal to 3%, optionally less than or equal to 2%, optionally less than or equal to 1%, optionally less than or equal to 0.5%, and in some respects, optionally less than or equal to 0.1%.

[0048] Additionally, the disclosure of the range includes the disclosure of all values ​​across the entire range and the disclosure of further subdivided ranges, including the endpoints and subranges given for these ranges.

[0049] Existing technologies improve interfacial impedance by injecting polymer electrolytes into the battery, which wet the electrode and solid electrolyte surfaces. However, existing processes not only involve excessively long wetting times and uneven wetting of the electrode surfaces, but also require injecting large amounts of polymer electrolytes into the battery, increasing raw material costs.

[0050] To address the aforementioned problems, this invention proposes a technical solution. The details are as follows:

[0051] The first aspect of this invention discloses a method for preparing a solid-state battery, the method comprising the following steps:

[0052] S1. Coat both sides of the film with electrolyte slurry to form a composite film;

[0053] S2. The composite film is directly stacked with the positive and negative electrode sheets to form a stacked body;

[0054] S3. Encapsulate the stacked body.

[0055] In this invention, the electrolyte slurry is generated by a eutectic reaction. The process of this invention is applicable to the coating of any eutectic electrolyte slurry. The electrolyte slurry is mainly formed by lithium salts and organic ligands through hydrogen bonding and Lewis acid-base interactions, without the need for solvents. The resulting electrolyte slurry can provide a wide electrochemical window, stable electrolyte / electrode interface compatibility, and specific ion / charge transport properties.

[0056] Specifically, the lithium salt can be any one or more of LiTFSI, LiNO3, LiClO4, LiDFOB, and LiCF3SO3, and the organic ligand can be any one or more of MAc, SN, Ace, and urea.

[0057] The lithium salt and corresponding organic ligand in the electrolyte slurry can be any of the combinations listed in the table below:

[0058] lithium salts organic ligands LiTFSI MAc LiTFSI SN LiTFSI / LiDFOB SN LiTFSI Ace <![CDATA[LiNO3]]> MAc <![CDATA[LiClO4]]> <![CDATA[MSM / H2O]]> LiTFSI Ace LiTFSI MAc <![CDATA[LiCF3SO3]]> Ace LiTFSI urea

[0059] This invention involves coating an electrolyte slurry onto both sides of a thin film, which is then cross-stacked with positive and negative electrode sheets. This arrangement ensures the slurry is present between the film and the positive electrode sheet, and between the film and the negative electrode sheet, allowing for thorough contact and wetting of both surfaces. By directly coating the electrolyte slurry between the film and the electrode sheets, this invention achieves sufficient contact between the slurry and both surfaces, improving both the wetting speed and the uniformity of the wetting process. Furthermore, this coating method also reduces the cost of the electrolyte slurry.

[0060] Specifically, the freezing point range of the electrolyte slurry is -80℃ to -30℃, and the viscosity of the electrolyte slurry is η, where 70 < η < 1500 (mPa·s).

[0061] In practical applications, the viscosity η of the electrolyte slurry can be selected as 70 mPa·s, 100 mPa·s, 200 mPa·s, 300 mPa·s, 400 mPa·s, 500 mPa·s, 600 mPa·s, 700 mPa·s, 800 mPa·s, 900 mPa·s, 1000 mPa·s, 1100 mPa·s, 1200 mPa·s, 1300 mPa·s, 1400 mPa·s, 1500 mPa·s, etc. The values ​​listed above are merely examples and not limitations. Those skilled in the art can freely implement any value within the range of 70 mPa·s to 1500 mPa·s, provided it does not exceed their understanding.

[0062] In this invention, the thin film has insulating properties. The thin film can be a separator or an electrolyte membrane, and it is disposed between the positive electrode and the negative electrode to prevent short circuit between the positive electrode and the negative electrode.

[0063] In one specific embodiment, the film is a separator, which includes one or more of the following: polyolefin separator, coated polyester film, cellulose film, polyimide film and polyamide film, spandex or aramid film, non-woven separator, and inorganic nano solid electrolyte layer.

[0064] In one specific embodiment, the thin film is an electrolyte membrane, which includes a solid electrolyte. The solid electrolyte includes at least one of sulfide solid electrolytes, halide solid electrolytes, and oxide solid electrolytes.

[0065] In some embodiments, in S1, the electrolyte coating is applied to both sides of the film simultaneously, forming an electrolyte coating on both sides of the film at the same time. Since the electrolyte coating of this invention does not require drying after application, if one side of the film is coated before the other, the side already coated with the electrolyte coating is easily damaged or contaminated during the coating process, affecting the consistency of the electrolyte coating thickness and consequently the wetting effect on the electrode. By applying the coating to both sides simultaneously, this problem can be avoided, further ensuring coating quality and product quality.

[0066] In some embodiments, in S1, the method of applying the electrolyte slurry onto the film includes any one of gravure roller forward coating, gravure roller reverse coating, and extrusion coating.

[0067] In one specific embodiment, an electrolyte slurry is coated onto a film using anilox forward coating. Specifically, two opposing anilox rollers are used to coat the film, with the film passing between the two rollers. After the slurry is applied to the anilox rollers, excess electrolyte slurry is scraped off by a squeegee. The anilox rollers rotate in the same direction as the film's movement, transferring the slurry from their surfaces onto the film, thus achieving coating. This electrolyte coating method ensures a uniform thickness and smooth edges of the electrolyte coating. Furthermore, by adjusting the distance between the squeegee and the anilox rollers, the thickness of the slurry on the rollers can be increased, thereby adjusting the coating thickness of the electrolyte slurry.

[0068] In one specific embodiment, an electrolyte slurry is coated onto a film using a reverse anilox coating process. Specifically, two opposing anilox rollers are used to coat the film, with the film passing between the two rollers. After the anilox rollers come into contact with the film and slurry is applied to them, excess electrolyte slurry is scraped off by a scraper. The rollers rotate in the opposite direction to the film's movement, transferring the slurry from the rollers onto the diaphragm. The thickness of the slurry transferred onto the diaphragm can be adjusted by controlling the rotation speed of the anilox rollers; a faster rotation speed results in a thicker electrolyte coating, while a slower rotation speed results in a thinner coating.

[0069] In one specific embodiment, the electrolyte slurry is coated onto a membrane by extrusion coating. Specifically, two opposing extrusion dies are used to coat the membrane, which passes between the two dies. The electrolyte slurry is extruded onto the diaphragm through the extrusion dies, forming an electrolyte coating on the diaphragm. The extrusion dies ensure more uniform electrolyte slurry output, guaranteeing consistent electrolyte coating thickness. By changing dies with different opening sizes, the thickness and coating area of ​​the electrolyte coating can be adjusted.

[0070] In some embodiments, the areal density of the electrolyte coating formed on both sides of the film is 1.5 g / m². 2 ~100g / m 2 .

[0071] In practical applications, the surface density of the electrolyte coating can be selected as 1.5 g / m². 2 5g / m 2 10g / m 2 15g / m 2 20g / m 2 25g / m 2 30g / m 2 35g / m 2 40g / m 2 45g / m 2 50g / m 2 55g / m 2 60g / m2 65g / m 2 70g / m 2 75g / m 2 80g / m 2 85g / m 2 90g / m 2 95g / m 2 100g / m 2 The values ​​listed above are merely examples and not limitations. Those skilled in the art can freely implement 1.5 g / m² without exceeding their understanding. 2～ 100g / m 2 Any value within the range.

[0072] In some embodiments, in step S2, the continuous composite film is folded in a Z-shape, and the positive and negative electrode sheets are sequentially and crosswise inserted between the folded composite films, so that there is a composite film between adjacent positive and negative electrode sheets. The electrolyte slurry on both sides of the composite film contacts the corresponding positive and negative electrode sheets and wets the surfaces of the positive and negative electrode sheets.

[0073] Specifically, one end of the continuous composite film is placed on a stacking platform to form the first layer. A positive electrode is then placed on the first layer, and the composite film is bent so that the bent portion overlaps the positive electrode to form the second layer. Next, a negative electrode is placed on the second layer, and the composite film is bent again so that the bent portion overlaps the negative electrode to form the third layer. This process of placing the positive electrode, bending the composite film, placing the negative electrode, and bending the composite film is repeated sequentially until a stack is formed. In the resulting stack, the composite film is folded in a Z-shape, and there is a layer of composite film between adjacent positive and negative electrodes.

[0074] It is understood that the above-described order of placing the positive and negative electrodes is merely an exemplary and non-limiting illustration. In other embodiments, the negative electrode may be placed on the first thin film first.

[0075] In some embodiments, when coating an electrolyte slurry on a continuous thin film, only one side of the first and last ends is coated with the electrolyte slurry. In the formed stack, the side of the composite film located at the bottom and top layers coated with the electrolyte slurry faces the positive or negative electrode sheet, thus wetting the corresponding positive or negative electrode sheet; the side not coated with the electrolyte slurry faces away from the corresponding positive or negative electrode sheet. This not only saves on the cost of the electrolyte slurry, but also avoids the electrolyte slurry on the stack being exposed on the outside, which would make assembly inconvenient.

[0076] In some implementations, the negative electrode is larger than the positive electrode. After stacking, the edges of the negative electrode extend beyond the edges of the positive electrode, preventing lithium plating on the negative electrode. The composite film is wider than the positive electrode, and the projection of the positive electrode falls on the composite film. This arrangement ensures isolation between the positive and negative electrodes, preventing short circuits between them.

[0077] In some embodiments, the preparation of a positive electrode and a negative electrode is further included before step S2; wherein, the method for preparing the positive electrode includes the following steps:

[0078] S11. Cut the positive electrode roll to form a positive electrode sheet;

[0079] S12. Inspect the positive electrode and remove defective positive electrode sheets;

[0080] The preparation method of the negative electrode includes the following steps:

[0081] S13. Cut the negative electrode roll to form a negative electrode sheet;

[0082] S14. Inspect the negative electrode and remove any defective negative electrode sheets.

[0083] The positive electrode roll is a rolled-up positive electrode strip. Independent sheet-shaped positive electrode plates are cut from the positive electrode roll to facilitate subsequent stacking with composite films. Similarly, the negative electrode roll is a rolled-up negative electrode strip. Independent sheet-shaped negative electrode plates are cut from the negative electrode roll to facilitate subsequent stacking with composite films.

[0084] In some embodiments, the positive electrode sheet includes a positive current collector and positive active material layers disposed on both sides of the positive current collector, and the negative electrode sheet includes a negative current collector and negative active material layers disposed on both sides of the negative current collector. After the positive electrode sheet and the negative electrode sheet are cross-stacked with the composite film, the positive active material layers on both sides of the positive current collector and the negative active material layers on both sides of the negative current collector are in contact with the electrolyte slurry on the composite film to be wetted.

[0085] In some embodiments, the positive electrode active material layer includes a positive electrode active material. Non-limiting examples of the positive electrode active material include any one or a combination of at least two of lithium cobalt oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium manganese oxide, lithium manganese iron phosphate, lithium vanadium phosphate, lithium vanadium oxide phosphate, lithium iron phosphate, lithium titanate, or lithium-rich manganese-based materials. Typical but non-limiting combinations include a combination of lithium cobalt oxide and lithium nickel cobalt manganese oxide, or a combination of lithium nickel cobalt manganese oxide and lithium nickel cobalt aluminum oxide.

[0086] In some embodiments, non-limiting examples of the positive current collector include, but are not limited to, aluminum (Al), aluminum alloy, stainless steel, titanium, titanium alloy, and nickel-plated steel.

[0087] In some embodiments, the negative electrode active material layer includes a negative electrode active material. The specific type of negative electrode active material is not limited and can be selected according to requirements. Specifically, the negative electrode active material is selected from natural graphite, artificial graphite, mesophase microcarbon spheres (MCMB), hard carbon, soft carbon, silicon, silicon-carbon composites, Li-Sn alloys, Li-Sn-O alloys, Sn, SnO, SnO2, and spinel-structured lithiated TiO2-Li4Ti5O. 12 One or more of Li-Al alloys. Non-limiting examples of carbon materials include crystalline carbon, amorphous carbon, and mixtures thereof. Crystalline carbon can be amorphous or flake-shaped, small flake-shaped, spherical, or fibrous natural or artificial graphite. Amorphous carbon can be soft carbon, hard carbon, mesophase pitch carbides, calcined coke, etc.

[0088] In some embodiments, the negative current collector may be selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, polymer substrate coated with conductive metal, and combinations thereof.

[0089] In some implementations, the stacked wafers are packaged into a pouch solid-state battery in step S3.

[0090] Specifically, two grooves for placing the stacked cells are punched out on the aluminum-plastic film using a stamping device. The stacked cells are placed in one of the grooves, and then the two grooves are snapped together. The tabs on the stacked cells extend out of the grooves, and finally the edges of the grooves are heat-sealed to form a soft-pack solid-state battery.

[0091] In some embodiments, in step S3, the stacked wafers are packaged into a prismatic solid-state battery.

[0092] Specifically, the tabs on the stacked body are welded to the terminals on the top cover assembly. Then, the stacked body is placed inside the metal shell, and the top cover assembly is fastened to the open end of the top of the metal shell. Finally, the edge of the top cover assembly is welded to the edge of the metal shell to form a square solid-state battery.

[0093] In some embodiments, step S3 further includes placing the packaged stack in an environment of 20°C to 60°C.

[0094] In practical applications, the ambient temperature for solid-state batteries to rest can be selected from 20℃, 25℃, 28℃, 30℃, 35℃, 38℃, 40℃, 45℃, 48℃, 50℃, 55℃, 58℃, and 60℃. The values ​​listed above are merely examples and not limitations. Those skilled in the art can freely implement any value within the range of 20℃ to 60℃ without exceeding their understanding. Such temperatures can improve the wetting rate of the electrolyte coating, and this temperature range will not have any other impact on the internal structure of the battery.

[0095] The second aspect of this invention discloses a solid-state battery fabrication system, in which the assembly method disclosed in the first aspect of this invention is performed, with reference to... Figure 1-3 The solid-state battery fabrication system includes a thin film unwinding roller 1, a coating device 2, a first feeding device 3, a second feeding device 4, and a stacking device 5.

[0096] Among them, the film unwinding roller 1 is used to unwind the film;

[0097] The coating device 2 is located downstream of the film unwinding roller 1, and a set of coating devices 2 is provided on both sides of the film for double-sided coating of electrolyte slurry on the film to generate a composite film.

[0098] The first feeding device 3 transports the positive electrode sheet. The first feeding device 3 is located on one side of the coating device 2 and upstream of the stacking device 5.

[0099] The second feeding device 4 is used to transport negative electrode sheets. The second feeding device 4 is located on the other side of the coating device 2 and upstream of the stacking device 5.

[0100] The stacking device 5 is used to receive positive electrode sheets, negative electrode sheets, and composite films, and to stack them.

[0101] The solid-state battery fabrication system described above first coats both sides of the film using the coating device 2 to form a composite film. Then, the composite film coated with electrolyte slurry is directly stacked with the positive and negative electrode sheets using the stacking device 5 to form a stack. This allows the electrolyte slurry on the composite film to fully contact and wet the positive and negative electrode sheets, improving the wetting efficiency and uniformity of the positive and negative electrode sheets, and also saving on the cost of electrolyte slurry.

[0102] It is understood that the packaging system of this application also includes packaging equipment, which can be a pouch battery packaging equipment or a prismatic battery packaging equipment. This is conventional battery packaging equipment in the prior art, and will not be described in detail here.

[0103] In some embodiments, the coating apparatus 2 includes a gravure roller 21, a scraper 22, and a hopper disposed on one side of the film, through which the film passes. The hopper, containing an electrolyte slurry, is located on one side of the gravure roller 21. The gravure roller 21 extends at least partially into the hopper, and its rotation carries the electrolyte slurry out. One end of the scraper 22 faces the gravure roller 21 and is used to scrape off excess electrolyte slurry from the roller. As the film passes through the gravure roller 21, the electrolyte slurry is coated onto the film, forming an area density of 1.5 g / m² on both sides of the film. 2 ~100g / m 2 Electrolyte coating.

[0104] In some specific implementations, refer to Figure 1 A coating device 2 is provided on both sides of the film unwinding roller 11. The gravure rollers 21 of the two coating devices 2 are arranged opposite each other. The film passes between the two gravure rollers 21, and the two gravure rollers 21 abut against the film. The scraper 22 is located upstream of the gravure roller 21. The rotation direction of the gravure roller 21 is the same as the movement direction of the diaphragm. The electrolyte slurry on the gravure roller 21 is transferred onto the diaphragm.

[0105] In this embodiment, by adjusting the distance between the scraper 22 and the gravure roller 21, the thickness of the paste adhering to the gravure roller 21 can be adjusted, thereby adjusting the thickness of the paste layer after coating. This method facilitates adjustment of the coating thickness and ensures coating efficiency.

[0106] In some other specific embodiments, refer to Figure 2 As shown, the scraper 22 is located downstream of the gravure roller 21. The rotation direction of the gravure roller 21 is opposite to the movement direction of the diaphragm. The diaphragm passes through the gravure roller 21, and the electrolyte slurry on the gravure roller 21 is transferred onto the diaphragm.

[0107] In this embodiment, the coating thickness can be adjusted by regulating the rotation speed of the gravure roller 21. The faster the rotation speed of the gravure roller 21, the thicker the coating; the slower the rotation speed of the gravure roller 21, the thinner the coating. This method facilitates the adjustment of the coating thickness and ensures coating efficiency.

[0108] In some other implementations, refer to Figure 3 As shown, the coating device 2 is an extrusion coating device, including an extrusion die 23 and a material box containing electrolyte slurry. One end of the extrusion die 23 is connected to the material box, and the other end faces the separator. The slurry is extruded and coated onto the separator through the extrusion die 23. By adjusting the width of the extrusion die 23, the thickness of the extruded electrolyte slurry can be adjusted, thereby adjusting the thickness of the electrolyte coating. This device can precisely ensure the uniformity of the electrolyte slurry coating and guarantee the wetting effect of the electrolyte slurry on the positive and negative electrode sheets.

[0109] In some embodiments, the first feeding device 3 and the second feeding device 4 can be any one of a robot, a conventional conveyor belt, and a negative pressure conveyor belt, which can transport the positive electrode sheet to the stacking device 5.

[0110] In some embodiments, the upstream of the first feeding device 3 further includes a positive electrode preparation device 6 for preparing positive electrode sheets. The first feeding device 3 includes a first unwinding roller 61, a first cutting assembly 62, and a detection assembly 7. The first feeding device 3 is a first conveyor belt 31, which is a negative pressure conveyor belt.

[0111] The first unwinding roller 61 is used to unwind the positive electrode winding;

[0112] The first cutting assembly 62 is disposed downstream of the first unwinding roller 61 and is used to cut the positive electrode roll into electrode sheets. The first cutting assembly 62 includes a first tab die-cutting structure 621 and a first electrode sheet cutting structure 622. The first tab die-cutting structure 621 is capable of cutting tabs on the positive electrode roll. The first electrode sheet cutting structure 622 is disposed downstream of the first tab die-cutting structure 621 and is used to cut the positive electrode roll with the tabs cut into positive electrode sheets.

[0113] The detection component 7 is located downstream of the first cutting component 62 and is used to detect the positive electrode sheet, screen out defective positive electrode sheets, and transport the defect-free positive electrode sheets to the stacking device.

[0114] Specifically, the detection component 7 includes a CCD detection device 71, a third conveyor belt 72, an abnormality magazine 73, and a rejection claw 74.

[0115] The third conveyor belt 72 is located downstream of the first electrode cutting structure 622, and its top surface is used to receive the cut positive electrode sheets. A CCD inspection device 71 is located on one side of the third conveyor belt 72. The CCD inspection device 71 has an image recognition program built-in, capable of acquiring images of the positive electrode sheets on the third conveyor belt 72, recognizing the images, and detecting defective positive electrode sheets. The CCD inspection device 71 and its built-in image recognition technology are existing technologies and will not be described in detail here.

[0116] The first conveyor belt 31 and the third conveyor belt 72 are offset from each other, with part of the first conveyor belt 31 located above the third conveyor belt 72. The bottom surface of the first conveyor belt 31 is equipped with a vacuum suction port, capable of picking up and transporting the positive electrode sheets from the third conveyor belt 72. An abnormality clip 73 and a rejection claw 74 are positioned opposite each other on either side of the first conveyor belt 31. When the CCD detection device 71 detects a defective positive electrode sheet, the rejection claw 74 strikes the first conveyor belt 31, removing the defective positive electrode sheet from the first conveyor belt 31 into the abnormality clip 73. Positive electrode sheets without abnormalities are transported by the first conveyor belt 31 to the stacking device 5.

[0117] In some embodiments, the upstream of the second feeding device 4 further includes a negative electrode preparation device 8 for preparing negative electrode sheets. The second feeding device 4 includes a second unwinding roller 81, a second cutting assembly 82, and also a set of detection components 7. The second feeding device 4 is a second conveyor belt 41, which is a negative pressure conveyor belt.

[0118] The second unwinding roller 81 is used to unwind the negative electrode winding;

[0119] The second cutting assembly 82 is disposed downstream of the second unwinding roller 81 and is used to cut the negative electrode roll into electrode sheets. The second cutting assembly 82 includes a second electrode tab die-cutting structure 821 and a second electrode sheet cutting structure 822. The second electrode tab die-cutting structure 821 is capable of cutting electrode tabs on the negative electrode roll. The second electrode sheet cutting structure 822 is disposed downstream of the second electrode tab die-cutting structure 821 and is used to cut the negative electrode roll with the electrode tabs cut into negative electrode sheets.

[0120] The detection component 7 is located downstream of the second cutting component 82 and is used to detect the negative electrode sheets cut by the second cutting component 82, screen out defective negative electrode sheets, and transport defect-free negative electrode sheets to the stacking device. The third conveyor belt 73 in the detection component 7 is located at the discharge end of the second electrode sheet cutting structure 822 and is used to receive the cut negative electrode sheets. The CCD detection device 71 is used to detect the negative electrode sheets on the third conveyor belt 73. The second conveyor belt 32 is offset from the third conveyor belt 72, with a portion of the second conveyor belt 32 located above the third conveyor belt 72. The bottom surface of the second conveyor belt 32 is used to adsorb and transfer the negative electrode sheets on the third conveyor belt 72. An abnormality clip 73 and a rejection claw 74 are located on both sides of the second conveyor belt 41 to remove defective negative electrode sheets.

[0121] Specifically, the stacking device 5 is used to zig-fold the composite film and to stack the positive and negative electrode sheets crosswise with the composite film. This application improves the stacking assembly efficiency of solid-state batteries by continuously coating the separator with a coating device and zig-stacking the positive, negative, and composite film sheets.

[0122] In some embodiments, the stacking device 5 includes a stacking stage 51, a first driving member 52, a carrier stage 53, a displacement plate 54, and a second driving member 55. The first driving member 52 and the stacking stage 51 are both mounted on the displacement plate 54. The output end of the first driving member 52 is connected to the stacking stage 51, driving the stacking stage 51 to reciprocate between the output ends of the first feeding device 3 and the second feeding device 4. The second driving member 55 is mounted on the carrier stage 53, and its output end is connected to the displacement plate 54, driving the displacement plate 54 to move up and down.

[0123] Specifically, the output ends of the first feeding device 3, the coating device 2, and the second feeding device 4 are sequentially arranged above the stacking table 51; the output end of the first driving member 52 is connected to the stacking table 51 and is used to drive the stacking table 51 to reciprocate between the output ends of the first feeding device 3 and the second feeding device 4 to realize the stacking process of the positive electrode and the separator.

[0124] The stacking table 51 is slidably engaged with the displacement plate 54. The first driving component 52 includes a motor 521 and a lead screw 522. The motor 521 is mounted on the displacement plate 54, and its output end is connected to the lead screw 522. The lead screw 522 passes through the stacking table 51 and is threadedly engaged with the stacking table 51. The motor 521 drives the lead screw 522 to rotate, which can drive the stacking table 51 to move, so that the stacking table 51 reciprocates between the output end of the first feeding device 3 and the output end of the second feeding device 4.

[0125] In the stacking device 5, the second driving component 55 is a cylinder. The second driving component 55 is mounted on the platform 53 and its output end is connected to the displacement plate 54, which can drive the displacement plate 54 to move up and down. The stacking table 51 is mounted on the displacement plate 54 and can follow the displacement plate 54 to move up and down, thereby realizing height adjustment to adjust the distance between the stacking table 51 and the discharge port of the first feeding device 3, the second feeding device 4 and the coating device 2.

[0126] The solid-state battery prepared in this embodiment has an electrolyte slurry coated on both sides of the thin film, so that the electrolyte slurry exists between the electrode and the thin film, which increases the contact area between the electrolyte slurry and the electrode. The electrolyte slurry can quickly wet the electrode, improve the wetting speed of the electrode, and also improve the uniformity of the wetting of the electrode.

[0127] It should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a solid-state battery, characterized in that, Includes the following steps: S1. Coat both sides of the film with electrolyte slurry to form a composite film; S2. The composite film is directly stacked with the positive electrode and the negative electrode to form a stacked body; S3. Encapsulate the stacked body.

2. The solid-state battery preparation method according to claim 1, characterized in that, The freezing point range of the electrolyte slurry is -80℃ to -30℃, and the viscosity of the electrolyte slurry is η, where 70 < η < 1500 (mPa·s).

3. The solid-state battery preparation method according to claim 1, characterized in that, In step S1, the method of applying the electrolyte slurry onto the film includes any one of gravure roller forward coating, gravure roller reverse coating, and extrusion coating.

4. The solid-state battery preparation method according to claim 1, characterized in that, In step S1, an electrolyte coating is simultaneously applied to both sides of the film, forming an electrolyte coating on both sides of the film; the areal density of the electrolyte coating is 1.5 g / m³. 2 ~100g / m 2 .

5. The solid-state battery preparation method according to claim 1, characterized in that, The step S3 further includes placing the packaged stacked body in an environment of 20°C to 60°C.

6. The solid-state battery preparation method according to claim 1, characterized in that, Before S2, the process further includes the preparation of the positive electrode and the preparation of the negative electrode; wherein, the method for preparing the positive electrode includes the following steps: S11. Cut the positive electrode roll to form the positive electrode sheet; S12. Inspect the positive electrode sheet and remove any defective positive electrode sheets; The method for preparing the negative electrode sheet includes the following steps: S13. Cut the negative electrode roll to form the negative electrode sheet; S14. Inspect the negative electrode sheet and remove defective negative electrode sheets.

7. A solid-state battery fabrication system, wherein the assembly method according to any one of claims 1-6 is performed in the assembly system, characterized in that, The solid-state battery fabrication system includes a thin film unwinding roller, a coating device, a first feeding device, a second feeding device, and a stacking device. The film unwinding roller is used to unwind the film; The coating device is located downstream of the film unwinding roller, and a set of the coating devices is provided on both sides of the film for double-sided coating of the electrolyte slurry on the film to generate a composite film. The first feeding device transports the positive electrode sheet. The first feeding device is located on one side of the coating device and upstream of the stacking device. The second feeding device is used to transport the negative electrode sheet. The second feeding device is located on the other side of the coating device and upstream of the stacking device. The stacking device is used to receive the positive electrode, the negative electrode, and the composite film, and to stack them.

8. The solid-state battery fabrication system according to claim 7, characterized in that, The coating apparatus includes a gravure roller, a scraper, and a material box; The material box is located on one side of the gravure roller, and the material box stores the electrolyte slurry. The gravure roller extends at least partially into the material box, and the gravure roller carries out the electrolyte slurry by rotating. One end of the scraper faces the gravure roller and is used to scrape off excess electrolyte slurry on the gravure roller.

9. The solid-state battery fabrication system according to claim 7, characterized in that, The upstream of the first feeding device also includes a positive electrode preparation device for preparing the positive electrode; The upstream of the second feeding device also includes a negative electrode preparation device for preparing negative electrode sheets.

10. The solid-state battery fabrication system according to claim 7, characterized in that, The stacking device includes a stacking stage, a first driving member, a platform, a displacement plate, and a second driving member; Both the first driving member and the stacking table are mounted on the displacement plate. The output end of the first driving member is connected to the stacking table, which is used to drive the stacking table to reciprocate between the output end of the first feeding device and the output end of the second feeding device. The second driving member is disposed on the platform, and the output end of the second driving member is connected to the displacement plate. The second driving member is used to drive the displacement plate to move up and down.

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