Isostatic pressing device and battery production equipment

Abstract

The utility model relates to an isostatic pressing device and battery production equipment, the isostatic pressing device comprises at least two layers of isostatic pressing films arranged at intervals along a preset direction, and an accommodating space for accommodating an electrode assembly is formed between every two adjacent layers of isostatic pressing films; wherein at least one layer of isostatic pressing film comprises an oil-proof layer and a heat sealing layer which are arranged in a stacked mode in the preset direction, and the heat sealing layer faces the containing space. The isostatic pressing film is in contact with the electrode assembly, pressure is applied to the electrode assembly so as to perform isostatic pressing treatment, in the process, the isostatic pressing film can be more conveniently separated from the electrode assembly, and the film is more convenient to detach; the probability that the heat conduction medium pollutes the electrode assembly in the isostatic pressing treatment process can be effectively reduced, and the oil-proof layer can be cleaned more conveniently.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to an isostatic pressing device and battery production equipment. Background Art

[0002] During the production process of solid-state batteries, the electrode components need to be subjected to isostatic pressing treatment to ensure close contact between the electrode and the solid electrolyte, thereby achieving the densification of the solid-state battery.

[0003] However, in the current isostatic pressing process, the structure of the isostatic pressing device is relatively complex, which not only makes the operation process cumbersome, but also makes the isostatic pressing device easily contaminated by the conductive medium, making it difficult to clean. Utility Model Content

[0004] Based on this, it is necessary to provide an isostatic pressing device and battery production equipment to address the problem that the current isostatic pressing device has a relatively complex structure, which not only makes the operation process cumbersome, but also makes the isostatic pressing device easily contaminated by the conductive medium, which is not conducive to cleaning.

[0005] In a first aspect, the present application provides an isostatic pressing device for performing isostatic pressing on an electrode assembly, the isostatic pressing device comprising at least two layers of isostatic pressing films spaced apart along a preset direction, a receiving space for receiving the electrode assembly being formed between each two adjacent layers of isostatic pressing films; wherein at least one layer of isostatic pressing film comprises an oil-proof layer and a heat-sealing layer stacked along a preset direction, and the heat-sealing layer is arranged facing the receiving space.

[0006] With the above structure, since the isostatic pressing film includes an oil-proof layer and a heat-sealing layer, it can not only effectively reduce the probability of the heat transfer medium contaminating the electrode assembly during the isostatic pressing process, but also make the oil-proof layer easier to clean.

[0007] In some embodiments, the material of the oil-proof layer includes one of polyethylene terephthalate, polyimide, polytetrafluoroethylene, aluminum foil, polyvinyl chloride, and polyamide.

[0008] Through the above structure, the oil-proof layer can better block conductive media such as oil substances, reduce the probability of conductive media contaminating the electrode assembly, and can better clean the isostatic pressing membrane, thereby improving usage efficiency.

[0009] In some embodiments, the material of the heat-sealing layer includes one of polypropylene, polyethylene, polyvinyl chloride, chlorinated polypropylene resin, ethylene-vinyl acetate copolymer, and polylactic acid.

[0010] Through the above structure, the heat sealing layer can better achieve heat sealing between two or more isostatic pressing films, so that the isostatic pressing films can better cover the electrode assembly in the accommodating space, thereby improving the effect of the isostatic pressing treatment.

[0011] In some embodiments, the thickness of the heat-sealing layer in a predetermined direction ranges from 5 μm to 300 μm. Setting the thickness of the heat-sealing layer within the above range can effectively improve the heat-sealing effect of the isostatically pressed film while controlling costs, thereby improving the effect of the isostatic pressing process.

[0012] In some embodiments, the thickness of the heat-sealing layer in a predetermined direction ranges from 10 μm to 200 μm. Furthermore, setting the thickness of the heat-sealing layer within the above range can further improve the heat-sealing effect of the isostatically pressed film.

[0013] In some embodiments, the isostatically pressed film further includes a support layer, which is arranged on a surface of each heat sealing layer facing the accommodating space along a preset direction, and the support layer is configured to provide support force for the pole ear portion of the electrode assembly in the accommodating space along the preset direction.

[0014] Through the above structure, the support layer can provide stable support for the pole ear during the isostatic pressing process, effectively reducing the probability of wrinkling of the pole ear.

[0015] In some embodiments, the material of the support layer includes one of rubber, silicone, chrome, and polyurethane.

[0016] As a result, the support layer can better support the pole ear portion, effectively reducing the probability of wrinkling of the pole ear portion during the isostatic pressing process.

[0017] In some embodiments, the thickness of the electrode assembly after isostatic pressing is a, the thickness of the electrode tab portion of the electrode assembly is b, and the thickness of the support layer is (ab) / 2.

[0018] By setting the thickness of the support layer within the above range, during the isostatic pressing process, the support layer can better fill the thickness difference between the pole ear and the main body, thereby providing more stable support for the pole ear and effectively improving the wrinkling phenomenon of the pole ear.

[0019] In some embodiments, each isostatically pressed film includes a pressurized area and a sealing area surrounding the pressurized area. In a plane perpendicular to a preset direction, the projection of the electrode assembly in the accommodating space falls within the projection range of the pressurized area; wherein the support layer is arranged in the pressurized area.

[0020] Through the above structure, the isostatic pressing film can be better wrapped around the periphery of the electrode assembly, so as to facilitate the isostatic pressing treatment of the electrode assembly.

[0021] In some embodiments, the isostatic pressing device further includes a pressurizing member, which is disposed along a preset direction on a side of each isostatic pressing film away from the accommodating space, for applying pressure to the corresponding isostatic pressing film.

[0022] In this way, the pressurizing member can drive the isostatic pressing films to approach each other along a preset direction, thereby pressurizing the electrode assembly in the accommodating space to achieve isostatic pressing treatment.

[0023] In a second aspect, the present application also provides a battery production device, comprising the isostatic pressing device as described above.

[0024] The above-mentioned isostatic pressing device and battery production equipment use an isostatic pressing film to contact the electrode assembly and apply pressure to the electrode assembly to perform isostatic pressing treatment. During this process, since the isostatic pressing film includes an oil-proof layer and a heat-sealing layer, it can not only effectively reduce the probability of the heat conduction medium contaminating the electrode assembly during the isostatic pressing process, but also the oil-proof layer can be easier to clean. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the structure of an isostatic pressing device according to one or more embodiments.

[0026] Figure 2 is a side view of an isostatic pressing apparatus according to one or more embodiments.

[0027] Figure 3 for Figure 2 A partial enlarged view of point A in the middle.

[0028] Explanation of the accompanying reference numerals: 100, isostatic pressing device; 200, electrode assembly; 201, main body; 202, pole ear; 10, isostatic pressing film; 20, accommodating space; 11, oil-proof layer; 12, heat-sealing layer; 13, supporting layer; 14, pressurizing area; 15, sealing area; a, preset direction. DETAILED DESCRIPTION

[0029] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0030] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0031] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0032] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0033] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0034] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0035] Currently, market developments indicate that battery applications are becoming increasingly widespread. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in other fields. As the power battery market continues to expand, market demand is also growing.

[0036] A battery cell is the smallest unit that makes up a battery device. Depending on their structure, battery cells can be divided into liquid battery cells and solid-state battery cells. Solid-state battery cells consist of a positive electrode, a negative electrode, and a solid electrolyte. Because they lack a liquid electrolyte, solid-state battery cells offer higher reliability and a longer service life.

[0037] Specifically, during the cycling of a solid-state battery cell, lithium ion transfer must occur at the solid-solid interface. Therefore, the tightness between the positive and negative electrodes and the electrolyte directly affects the ionic conductivity of the solid-state battery cell. The tightness between the positive and negative electrodes and the electrolyte is also the degree of densification of the solid-state battery cell.

[0038] Based on this, isostatic pressing is currently commonly used to achieve the densification of solid-state battery cells. During the isostatic pressing process, liquids are also needed as media for pressure and heat conduction, such as water, silicone oil, vegetable oil, etc. In order to achieve good densification, higher temperatures are required to improve the creep properties of the powder during the isostatic pressing process. When water is used as a conductive medium, the temperature cannot exceed 100°C. Therefore, oil substances become an indispensable component for pressure and heat conduction during the isostatic pressing process of solid-state battery cells.

[0039] Current isostatic pressing devices are usually complex in structure. During operation, the process is not only cumbersome but also easily contaminated by conducting media such as oil substances and difficult to clean.

[0040] Based on the above considerations, in order to solve the problem that the current isostatic pressing device has a relatively complex structure, which not only has a cumbersome operation process, but also is easily contaminated by the conductive medium, which is not conducive to cleaning, an isostatic pressing device is provided in one or more embodiments of the present application, which utilizes an isostatic pressing film to contact the electrode assembly and apply pressure to the electrode assembly to perform isostatic pressing treatment. In this process, since the isostatic pressing film includes an oil-proof layer and a heat-sealing layer, it can not only effectively reduce the probability of the heat-conductive medium contaminating the electrode assembly during the isostatic pressing process, but also the oil-proof layer can be more convenient to clean.

[0041] Please also refer to Figure 1 、 Figure 2 as well as Figure 3 One embodiment of the present application provides an isostatic pressing apparatus 100 for performing isostatic pressing on an electrode assembly 200. The isostatic pressing apparatus 100 includes at least two layers of isostatic pressing films 10 spaced apart along a predetermined direction a. A receiving space 20 for accommodating the electrode assembly 200 is formed between each adjacent layer of isostatic pressing films 10. The at least one layer of isostatic pressing films 10 includes an oil-repellent layer 11 and a heat-sealing layer 12 stacked along the predetermined direction a, with the heat-sealing layer 12 facing the receiving space 20.

[0042] It should be noted that the isostatic pressing apparatus 100 is a structure capable of performing isostatic pressing on the electrode assembly 200 of a solid-state battery cell. Specifically, the isostatic pressing apparatus 100 applies pressure to the electrode assembly 200 of the solid-state battery cell, thereby achieving good solid-solid contact between the positive and negative electrodes in the electrode assembly 200 and the solid electrolyte, increasing the contact area between the interfaces and improving the densification of the solid-state battery cell.

[0043] The isostatic pressing device 100 includes at least two layers of isostatic pressing films 10, each of which is spaced apart from each other along a predetermined direction a, with a receiving space 20 formed between two adjacent layers of isostatic pressing films 10. The electrode assembly 200 can be placed in the receiving space 20, and then the two adjacent layers of isostatic pressing films 10 can be moved toward the electrode assembly 200 in the receiving space 20. External force can then be applied to the electrode assembly 200, thereby achieving close contact between the positive and negative electrode sheets in the electrode assembly 200 and the solid electrolyte.

[0044] It can be understood that the isostatic pressing device 100 also includes other structures, such as a pressure member, which applies pressure to the corresponding isostatic pressing film 10 so that adjacent isostatic pressing films 10 can approach each other, thereby applying pressure to the electrode assembly 200 in the accommodating space 20.

[0045] For ease of understanding, the following description uses a two-layer isostatically pressed film 10 as an example. Specifically, the isostatically pressed film 10 comprises an upper and lower layer, and the two layers of isostatically pressed film 10 are spaced apart along a predetermined direction a, forming a receiving space 20 therebetween. When the electrode assembly 200 is placed within the receiving space 20, the upper and lower layers of isostatically pressed film 10 move closer together, applying pressure to the electrode assembly 200 within the receiving space 20.

[0046] One or two layers of the isostatically pressed film 10 may include an oil-proof layer 11 and a heat-sealing layer 12 stacked along a preset direction a, and the heat-sealing layer 12 is located on the side facing the accommodating space 20, that is, the oil-proof layer 11 is arranged on the side surface of the heat-sealing layer 12 facing away from the accommodating space 20.

[0047] Specifically, the oil-proof layer 11 and the heat-sealing layer 12 can be bonded together by a composite method. The composite method refers to a technology that combines two or more different film materials together to form a composite film with new functions. Among them, the main composite methods include dry composite and co-extrusion composite. Dry composite refers to first applying glue on a film, removing the solvent in an oven, and then bonding it with another film by heating and pressurizing. Co-extrusion composite refers to simultaneously extruding different polymers through multiple extrusion devices, converging at a die head, and then stretching to form a multi-layer co-extruded composite film.

[0048] Furthermore, the heat sealing layer 12 is located on the inner side close to the accommodating space 20. During the isostatic pressing process, the two layers of isostatic pressing films 10 can be heat sealed under a vacuum environment through their respective heat sealing layers 12 to better wrap the electrode assembly 200 between the two layers of isostatic pressing films 10 and perform isostatic pressing.

[0049] Furthermore, the outer surface of the heat-sealing layer 12 is provided with an oil-repellent layer 11. During the isostatic pressing process, the isostatic pressing film 10, which covers the electrode assembly 200, is typically placed in a conductive medium containing an oil. Thus, the oil-repellent layer 11 can better block oil, reducing the probability of the conductive medium contaminating the electrode assembly 200.

[0050] After the isostatic pressing process is completed, the outer oil-proof layer 11 can more conveniently remove oil stains, making it easier to clean the isostatic pressing device 100 .

[0051] Through the above structure, the isostatic pressing film 10 can be more conveniently separated from the electrode assembly 200, and the film can be removed more conveniently. In addition, since the isostatic pressing film 10 includes an oil-proof layer 11 and a heat-sealing layer 12, it can not only effectively reduce the probability of the heat conduction medium contaminating the electrode assembly 200 during the isostatic pressing process, but also the oil-proof layer 11 can be easier to clean.

[0052] In some embodiments, the material of the oil-proof layer 11 includes one of polyethylene terephthalate, polyimide, polytetrafluoroethylene, aluminum foil, polyvinyl chloride, and polyamide.

[0053] Specifically, the material of the oil-proof layer 11 may include one of polyethylene terephthalate (PET), polyimide (PI), polytetrafluoroethylene (PTFE), aluminum foil, polyvinyl chloride (PVC), and polyamide (PA).

[0054] Through the above structure, the oil-proof layer 11 can better block conductive media such as oil substances, reduce the probability of conductive media contaminating the electrode assembly 200, and can better clean the isostatically pressed membrane 10, thereby improving usage efficiency.

[0055] Furthermore, the thickness of the oil-repellent layer 11 affects the overall cost of the isostatic pressing apparatus 100 and the manufacturing process difficulty. Therefore, the thickness of the oil-repellent layer 11 can be set to a range of 5 μm to 200 μm. Specifically, the thickness of the oil-repellent layer 11 can be, but is not limited to, 5 μm, 50 μm, 100 μm, 150 μm, or 200 μm.

[0056] In some embodiments, the material of the heat-sealing layer 12 includes one or more of polypropylene, polyethylene, polyvinyl chloride, chlorinated polypropylene resin, stretched polypropylene film, ethylene-vinyl acetate copolymer, and polylactic acid.

[0057] Specifically, the material of the heat-sealing layer 12 may include one of polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), chlorinated polypropylene resin (CPP), ethylene-vinyl acetate copolymer (EVA), and polylactic acid (PLA).

[0058] Through the above structure, the heat sealing layer 12 can better achieve heat sealing between two or more isostatic pressing films 10, so that the isostatic pressing film 10 can better cover the electrode assembly 200 in the accommodating space 20, thereby improving the effect of the isostatic pressing treatment.

[0059] In some embodiments, in the preset direction a, the thickness of the heat-sealing layer 12 ranges from 5 μm to 300 μm.

[0060] Specifically, the thickness range of the heat-sealing layer 12 will affect the overall cost of the isostatic pressing apparatus 100 and the heat-sealing effect between the isostatic pressing films 10 , thereby affecting the isostatic pressing effect of the electrode assembly 200 .

[0061] Therefore, setting the thickness of the heat-sealing layer 12 within the above range can effectively improve the heat-sealing effect of the isostatic pressing film 10 while controlling the cost, thereby improving the effect of the isostatic pressing treatment.

[0062] As a specific example, the thickness of the heat-seal layer 12 can be, but is not limited to, 5 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, or 300 μm.

[0063] In some embodiments, the thickness of the heat-seal layer 12 is in the range of 10 μm to 200 μm in the preset direction a.

[0064] Further, by setting the thickness of the heat-seal layer 12 in the above range, the heat-seal effect of the isostatic pressing film 10 can be further improved.

[0065] As a specific example, the thickness of the heat-seal layer 12 can be, but is not limited to, 10 μm, 30 μm, 50 μm, 70 μm, 90 μm, 110 μm, 130 μm, 150 μm, 170 μm, or 200 μm.

[0066] In some embodiments, the isostatic pressing film 10 further comprises a support layer 13, which is arranged on the side surface of each heat-seal layer 12 facing the accommodation space 20 along the preset direction a, and the support layer 13 is configured to be able to provide a support force to the tab portion 202 of the electrode assembly 200 in the accommodation space 20 along the preset direction a.

[0067] It should be noted that the electrode assembly 200 generally comprises a main body portion 201 and a tab portion 202, and the portion on the current collector coated with active material forms the main body portion 201 of the electrode assembly 200, and the portion not coated with active material forms the tab portion 202. When the positive electrode sheet, the negative electrode sheet, and the solid-state electrolyte are laminated or wound to form the electrode assembly 200, the tab portion 202 can be located on one side or both sides of the main body portion 201 along the length direction of the electrode assembly 200.

[0068] Since the thickness of the tab portion 202 is thinner than that of the main body portion 201, and the tab portion 202 is located on one side or both sides of the main body portion 201. In addition, the main body portion 201 of the electrode assembly 200 has a large pore due to the coating of active material. During the isostatic pressing process, the main body portion 201 is easily compressed, and the size in each direction will be reduced, while the tab portion 202 is actually a current collector, which is not easily compressed. In this case, the tab portion 202 is prone to wrinkling.

[0069] Based on this, the support layer 13 is arranged on the inner surface of the side of the heat-seal layer 12 facing the accommodation space 20, and the position of the support layer 13 corresponds to that of the tab portion 202 of the electrode assembly 200. That is, when the electrode assembly 200 is placed into the accommodation space 20, the tab portion 202 can be pressed against the support layer 13 along the preset direction a, so that the support layer 13 can provide a certain support force to the tab portion 202.

[0070] It can be understood that the width and length of the support layer 13 are designed to match the width and length of the tab portion 202, so that when the tab portion 202 is stably supported on the support layer 13, the support layer 13 will not affect the main body portion 201.

[0071] Therefore, through the above structure, the support layer 13 can provide stable support for the tab portion 202 during the isostatic pressing process, effectively reducing the probability of wrinkles occurring in the tab portion 202.

[0072] In some embodiments, the material of the support layer 13 includes one of rubber, silicone, chromium, and polyurethane.

[0073] Specifically, the material of the support layer 13 can include one of rubber, silicone, chromium, and polyurethane.

[0074] Therefore, the support layer 13 can better support the tab portion 202, effectively reducing the probability of wrinkles occurring in the tab portion 202 during the isostatic pressing process.

[0075] In some embodiments, the thickness of the electrode assembly 200 after isostatic pressing is a, the thickness of the tab portion 202 of the electrode assembly 200 is b, and the thickness of the support layer 13 is (a-b) / 2.

[0076] Specifically, the thickness of the support layer 13 will directly affect the improvement degree of wrinkles in the tab portion 202, which may result in insufficient support of the tab portion 202 and thus cannot effectively improve the wrinkles problem, or too much support of the tab portion 202 will also affect the connection between the main body portion 201 and the tab portion 202.

[0077] Therefore, the thickness of the support layer 13 is set in the above range, and during the isostatic pressing process, the support layer 13 can better fill the thickness difference between the tab portion 202 and the main body portion 201, thereby forming a more stable support for the tab portion 202, effectively improving the wrinkles phenomenon of the tab portion 202.

[0078] In some embodiments, each isostatic pressing film 10 includes a pressurized area 14 and a sealing area 15 surrounding the outer periphery of the pressurized area 14, and in a plane perpendicular to the predetermined direction a, the projection of the electrode assembly 200 in the containing space 20 falls within the projection range of the pressurized area 14. The support layer 13 is arranged in the pressurized area 14.

[0079] It should be noted that after the electrode assembly 200 is placed in the corresponding containing space 20, the adjacent two layers of isostatic pressing films 10 are usually sealed on three sides, and then vacuumized from the fourth side, and then sealed on the fourth side, so that the electrode assembly 200 can be more stably placed in the containing space 20, facilitating the isostatic pressing process.

[0080] Based on this, when the electrode assembly 200 is located in the accommodating space 20, the electrode assembly 200 is actually located between the pressurized areas 14 of two adjacent layers of isostatically pressed films 10, and the sealing area 15 is located on the periphery of the corresponding pressurized area 14. During packaging, the sealing area 15 can be packaged so that the isostatically pressed film 10 can better cover the electrode assembly 200.

[0081] Through the above structure, the isostatic pressing film 10 can be better wrapped around the periphery of the electrode assembly 200, so as to facilitate the isostatic pressing treatment of the electrode assembly 200.

[0082] In some embodiments, the isostatic pressing device 100 further includes a pressurizing member (not shown in the figure), which is arranged along a preset direction a on a side of each isostatic pressing film 10 away from the accommodating space 20 for applying pressure to the corresponding isostatic pressing film 10 .

[0083] Specifically, the pressure member can be arranged above the upper isostatic pressing film 10, and below the lower isostatic pressing film 10. The pressure members can approach or move away from each other along the preset direction a. In this way, the pressure member can drive the isostatic pressing films 10 to approach each other along the preset direction a, thereby pressurizing the electrode assembly 200 in the accommodating space 20 to achieve isostatic pressing treatment.

[0084] Based on the same concept as the above-mentioned isostatic pressing device 100 , the present application also provides a battery production device, including the above-mentioned isostatic pressing device 100 .

[0085] According to one or more embodiments, the substrate is first pretreated, that is, the oil-proof layer 11 is corona treated to increase wettability. At the same time, the heat-sealing layer 12 is corona treated to improve adhesive adhesion and perform surface dust removal.

[0086] Furthermore, an adhesive is applied on the oil-proof layer 11 or the heat-sealing layer 12 to bond the two together, the adhesive is dried in an oven, and then the oil-proof layer 11 and the heat-sealing layer 12 are compounded by a hot pressing roller.

[0087] Glue is applied to the corresponding position of the surface of the heat-sealing layer 12 facing away from the oil-proof layer 11 , and then the supporting layer 13 is pasted to the corresponding position, and is cured and dried to finally obtain the isostatically pressed film 10 .

[0088] The isostatically pressed film 10 is arranged at intervals along a preset direction a, the electrode assembly 200 is placed in the accommodating space 20, and then the isostatically pressed film 10 is sealed on three sides and vacuum-sealed from the fourth side so that the electrode assembly 200 can be stably wrapped inside the isostatically pressed film 10.

[0089] The isostatically pressed film 10 and the electrode assembly 200 therein are placed together in the isostatic pressing device 100 for isostatic pressing treatment. After the isostatic pressing treatment, the isostatically pressed film 10 can be removed to obtain the densified electrode assembly 200 .

[0090] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0091] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. An isostatic pressing device, characterized in that: Used to perform isostatic pressing on the electrode assembly, the isostatic pressing device comprising at least two layers of isostatic pressing films spaced apart along a preset direction, with a receiving space for receiving the electrode assembly formed between each two adjacent layers of the isostatic pressing films; Wherein, at least one layer of the isostatically pressed film includes an oil-proof layer and a heat-sealing layer stacked along the preset direction, and the heat-sealing layer is arranged facing the accommodating space.

2. The isostatic pressing device according to claim 1, characterized in that The material of the oil-proof layer includes one of polyethylene terephthalate, polyimide, polytetrafluoroethylene, aluminum foil, polyvinyl chloride, and polyamide.

3. The isostatic pressing device according to claim 1, characterized in that The material of the heat sealing layer includes one of polypropylene, polyethylene, polyvinyl chloride, chlorinated polypropylene resin, ethylene-vinyl acetate copolymer, and polylactic acid.

4. The isostatic pressing device according to any one of claims 1 to 3, characterized in that: In the preset direction, the thickness of the heat-sealing layer ranges from 5 μm to 300 μm.

5. The isostatic pressing device according to claim 4, characterized in that In the preset direction, the thickness of the heat-sealing layer ranges from 10 μm to 200 μm.

6. The isostatic pressing device according to claim 1, characterized in that The isostatically pressed film further includes a support layer, which is arranged on a surface of each heat sealing layer facing the accommodation space along the preset direction, and the support layer is configured to provide support force for the electrode ear portion of the electrode assembly in the accommodation space along the preset direction.

7. The isostatic pressing device according to claim 6, characterized in that The material of the support layer includes one of rubber, silicone, chrome and polyurethane.

8. The isostatic pressing device according to claim 6 or 7, characterized in that: The thickness of the electrode assembly after isostatic pressing is a, the thickness of the electrode lug portion of the electrode assembly is b, and the thickness of the support layer is (ab) / 2.

9. The isostatic pressing device according to claim 6, characterized in that Each of the isostatically pressed films includes a pressurizing area and a sealing area surrounding the pressurizing area, and in a plane perpendicular to the preset direction, a projection of the electrode assembly in the accommodating space falls within a projection range of the pressurizing area; Wherein, the support layer is arranged in the pressurized area.

10. The isostatic pressing device according to claim 1, characterized in that The isostatic pressing device further includes a pressurizing member, which is arranged along the preset direction on a side of each isostatic pressing film away from the accommodating space and is used to apply pressure to the corresponding isostatic pressing film.

11. A battery production device, characterized in that: The invention comprises the isostatic pressing device according to any one of claims 1 to 10.

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