Extrusion film forming mechanism, pole piece production line and battery production line

Abstract

The utility model discloses an extrusion film-forming mechanism, a pole piece production line and a battery production line, and relates to the technical field of battery production, the extrusion film-forming mechanism comprises a first shell, an extrusion piece and a tabletting structure, an extrusion cavity and a first discharge port communicated with the extrusion cavity are formed in the first shell, and the first discharge port is communicated with the extrusion cavity; the first shell comprises a first shell main body and a first non-metal layer covering the inner wall surface of the first shell main body; the extrusion part is movably arranged in the extrusion cavity, a second non-metal layer is arranged on the surface layer of the extrusion part, and the extrusion part is arranged to be used for extruding slurry and conveying the slurry to the first discharge port; the tabletting structure is arranged at the first discharge port and is provided with a film forming gap, and the film forming gap is used for allowing the slurry to pass through and forming the slurry into a film. According to the technical scheme, the performance of the pole piece and the battery monomer can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery production technology, and in particular to an extrusion film forming mechanism, a pole piece production line, and a battery production line. Background Art

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry. Electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of the sustainable development of the automotive industry. For electric vehicles, battery technology is a key factor in their development.

[0003] The pole piece on a battery cell usually includes a current collector and a diaphragm arranged on at least one side of the current collector. In related technologies, the diaphragm is prepared and formed by extrusion film forming. During the preparation process, wear will occur between the moving parts in the extrusion film forming machine and the body cavity wall of the extrusion film forming machine, resulting in metal particles. As a result, the metal particles in the raw materials used to make the diaphragm exceed the standard, affecting the performance of the pole piece and the battery cell. Utility Model Content

[0004] The main purpose of this application is to propose an extrusion film forming mechanism, a pole piece production line and a battery production line, aiming to improve the performance of pole pieces and battery cells.

[0005] To achieve the above objectives, the extrusion film forming mechanism proposed in this application includes:

[0006] A first shell, wherein an extrusion cavity and a first discharge port communicating with the extrusion cavity are formed in the first shell, and the first shell includes a first shell body and a first non-metallic layer covering an inner wall surface of the first shell body;

[0007] an extrusion member, the extrusion member being movably disposed in the extrusion cavity, the surface of the extrusion member being provided with a second non-metallic layer, the extrusion member being configured to extrude slurry and deliver the slurry to the first discharge port; and

[0008] A sheet pressing structure is provided at the first discharge port and is provided with a film forming gap, wherein the film forming gap is configured to allow the slurry to pass through and be formed into a membrane.

[0009] The technical solution of the present application is to set a first non-metallic layer on the inner wall of the extrusion cavity of the extrusion film-forming mechanism, and set a second non-metallic layer on the surface of the extrusion part used to extrude the slurry. This arrangement can avoid the wear of the extrusion part and the first shell to produce metal particles when the extrusion film-forming mechanism is running, thereby avoiding the mixing of metal particles in the slurry for making the diaphragm, so as to avoid the metal particles of the diaphragm exceeding the standard, improve the performance of the electrode, and thus enhance the safety, electrochemical performance and cycle life of the battery cell.

[0010] In one embodiment, the material of the first non-metallic layer is set to be engineering plastic.

[0011] By adopting the above method, since the comprehensive structural performance of engineering plastics is good, it has good rigidity, wear resistance, corrosion resistance, structural strength and hardness; thus, the first non-metallic layer has high rigidity and structural strength, good wear resistance, high pressure bearing capacity, and is not easy to wear.

[0012] In one embodiment, the material of the second non-metallic layer is set to be an inorganic non-metallic material.

[0013] By adopting the above method, since the inorganic non-metallic material has high hardness, wear resistance and corrosion resistance, the second non-metallic layer on the surface of the extruded part can have good wear resistance and corrosion resistance, and the structural strength is high and not easy to wear.

[0014] In one embodiment, the extrusion component includes two extrusion screws arranged side by side, the extrusion screws are rotatable, and the surface layer of the extrusion screws is provided with the second non-metallic layer.

[0015] This setting method is to set the extrusion film-forming mechanism as a twin-screw extrusion mechanism. The twin-screw extrusion mechanism has a strong extrusion capacity, which can better squeeze the voids in the slurry and drive the material into the space occupied by the voids, so as to obtain a material with consistent uniformity, so that the formed film has good lateral consistency, which is conducive to controlling the thickness and uniformity of the formed film.

[0016] In one embodiment, the first shell body includes a first main body portion and a first limiting portion, the first main body portion is provided with the extrusion cavity, and a first feed port and the first discharge port connected to the extrusion cavity, the first limiting portion is protruded on the inner side of the first feed port, and the first non-metallic layer is adhered to the inner wall of the first main body portion and abuts against the first limiting portion.

[0017] By adopting the above method, by protruding a first limiting portion on the inner side of the first feed port and using the first limiting portion to limit the first non-metallic layer, the first non-metallic layer can be prevented from escaping from the first feed port, thereby improving the overall structural stability of the first shell.

[0018] In one embodiment, the thickness of the first non-metallic layer is set to 10 mm to 20 mm.

[0019] This arrangement enables the first non-metallic layer to have better pressure-bearing capacity; and, since the extrusion cavity has size requirements, it is necessary to have sufficient space for accommodating the extrusion parts and slurry, and it is also necessary to ensure the structural strength of the first shell body, and it is necessary to avoid the wall thickness of the first shell body being too thin. By setting the thickness of the first non-metallic layer to no more than 20 mm, it is possible to avoid the size of the first shell being too large, or the wall thickness of the first shell body being too thin to affect the structural strength.

[0020] In one embodiment, the first shell body and the first non-metallic layer are adhesively connected.

[0021] In this arrangement, the first shell body and the first non-metallic layer are easy to assemble and have high connection strength.

[0022] In one embodiment, the extrusion component includes two extrusion screws arranged side by side, the extrusion screws are rotatable, and the surface layer of the extrusion screws is provided with the second non-metallic layer.

[0023] This setting method is to set the extrusion film-forming mechanism as a twin-screw extrusion mechanism. The twin-screw extrusion mechanism has a strong extrusion capacity, which can better squeeze the voids in the slurry and drive the material into the space occupied by the voids, so as to obtain a slurry with consistent uniformity, so that the formed film has good lateral consistency, which is conducive to controlling the thickness and uniformity of the film.

[0024] In one embodiment, the sheet pressing structure includes rollers arranged opposite to each other, and the film forming gap is formed between the two rollers.

[0025] With this arrangement, the rollers can rotate during the process of the slurry being extruded from the film-forming gap to form a film, thereby reducing the friction between the slurry and the tableting structure and ensuring that the material can maintain a stable state during the extrusion process, thereby preventing the material from sagging or deviating from the predetermined track.

[0026] This application also proposes a pole piece production line, comprising:

[0027] The extrusion film forming mechanism as described in any of the above embodiments; and

[0028] The composite mechanism is arranged downstream of the extrusion film forming mechanism, and is configured to composite the membrane and the current collector to form a pole piece.

[0029] The electrode production line proposed in the present application adopts the extrusion film-forming mechanism in the aforementioned embodiment to prepare the diaphragm, and composites the diaphragm and the current collector into the electrode through a composite mechanism. Since the cavity wall of the first shell in the extrusion film-forming mechanism is covered with a first non-metallic layer and the surface of the extruded part is provided with a second non-metallic layer, the generation of metal particles during the extrusion film-forming process can be avoided, thereby avoiding the mixing of metal particles into the slurry for making the diaphragm, avoiding the metal particles of the diaphragm exceeding the standard, improving the performance of the electrode, and thus improving the electrochemical performance and cycle life of the battery.

[0030] In one embodiment, the electrode production line further includes a kneading mechanism, which is provided upstream of the extrusion film forming mechanism, and includes:

[0031] a second shell, the second shell being provided with a kneading cavity and a second discharge port communicating with the kneading cavity, the second shell comprising a second shell body and a third non-metallic layer covering an inner wall of the second shell body;

[0032] A stirring blade, the stirring blade is movably provided in the kneading chamber, and the stirring blade is configured to stir the mixed material; and

[0033] A feeding screw, one end of which is arranged toward the second discharge port, and a fourth non-metallic layer is provided on the surface of the stirring blade and the feeding screw.

[0034] With this arrangement, the material and slurry can be stirred and mixed by the stirring blades in the kneading chamber of the second shell, and then delivered to the discharge port by the feed screw. This arrangement allows the slurry to be mixed more evenly. A third non-metallic layer is provided on the inner wall of the second shell, and a fourth non-metallic layer is provided on the surface of the stirring blades and feed screw. This prevents the generation of metal particles due to wear of the second shell, stirring blades, and feed screw during operation of the kneading mechanism. This prevents the incorporation of metal particles into the slurry used to make the diaphragm, preventing the diaphragm from exceeding the metal particle limit, improving the performance of the electrode, and thereby enhancing the safety, electrochemical performance, and cycle life of the battery.

[0035] In one embodiment, the material of the third non-metallic layer is set to be engineering plastic.

[0036] By adopting the above method, since the comprehensive structural performance of engineering plastics is good, it has good rigidity, wear resistance, corrosion resistance, structural strength and hardness; thus, the third non-metallic layer has high rigidity and structural strength, good wear resistance, high pressure bearing capacity, and is not easy to wear.

[0037] In one embodiment, the fourth non-metallic layer is made of an inorganic non-metallic material.

[0038] By adopting the above method, since inorganic non-metallic materials have high hardness, wear resistance and corrosion resistance, the fourth non-metallic layer on the surface of the stirring blade and the feeding screw can have good wear resistance and corrosion resistance, and the structural strength is high and not easy to wear.

[0039] In one embodiment, the thickness of the third non-metallic layer is set to 10 mm to 20 mm.

[0040] This arrangement enables the third non-metallic layer to have better pressure-bearing capacity; and, since the extrusion chamber has size requirements, it is necessary to have sufficient space for accommodating structures such as stirring blades and feeding screws, and it is also necessary to ensure the structural strength of the second shell body, and it is necessary to avoid the wall thickness of the second shell body being too thin. By setting the thickness of the third non-metallic layer to no more than 20 mm, it is possible to avoid the size of the second shell being too large, or the wall thickness of the second shell body being too thin to affect the structural strength.

[0041] In one embodiment, the second shell body includes a second main body portion and a second limiting portion, the second main body portion is provided with the kneading cavity, and an opening connected to the kneading cavity and the second discharge port, the second limiting portion is provided on the inner side of the opening, and the third non-metallic layer is attached to the inner wall of the second main body portion and abuts against the second limiting portion.

[0042] This arrangement prevents the third non-metallic layer from falling out of the opening by protruding a second limiting portion on the inner side of the opening and limiting the third non-metallic layer by the second limiting portion, thereby improving the overall structural stability of the second shell.

[0043] In one embodiment, the second shell body and the third non-metallic layer are adhesively connected.

[0044] In this arrangement, the second shell body and the third non-metallic layer are easy to assemble and have high connection strength.

[0045] In one embodiment, the composite mechanism includes a plurality of pressing rollers, wherein a composite gap for the membrane and the current collector to pass through is formed between two adjacent pressing rollers.

[0046] In this arrangement, multiple pressure rollers are arranged in the composite structure, so that a composite gap is formed between two adjacent pressure rollers for composite the diaphragm and the current collector into one. When the diaphragm and the current collector pass through the composite gap at the same time, they are combined into one under the extrusion of the two pressure rollers to form a pole piece, and the two pressure rollers can rotate to reduce the friction between the diaphragm and the composite structure during the composite process, avoid the diaphragm from being stretched and deformed, and improve the preparation yield and performance of the pole piece.

[0047] In one embodiment, the electrode production line further includes a drying mechanism, which is located downstream of the composite mechanism and is configured to dry the electrode.

[0048] By adopting the above method, the electrode can be dried by the drying mechanism, which is conducive to quickly evaporating the moisture in the electrode, making the electrode dry and shaped, thereby ensuring the performance of the electrode.

[0049] In one embodiment, the electrode production line further includes a winding mechanism, which is located downstream of the composite mechanism and is configured to wind up the electrode.

[0050] By adopting the above method, the composite-molded electrode sheet can be rolled into a coil by using a winding mechanism, so as to facilitate the transportation and storage of the electrode sheet.

[0051] The present application also proposes a battery production line, including a pole piece production line as described in any of the aforementioned embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0053] Figure 1 A structural diagram of an embodiment of an extrusion film forming mechanism provided according to some embodiments of the present application;

[0054] Figure 2 for Figure 1 Top view of the extrusion film forming mechanism;

[0055] Figure 3 A structural diagram of an embodiment of a pole piece production line provided according to some embodiments of the present application;

[0056] Figure 4 A structural diagram of an embodiment of a kneading mechanism in a pole piece production line provided according to some embodiments of the present application;

[0057] Figure 5 2 is a structural diagram of the second shell of the kneading mechanism according to some embodiments of the present application.

[0058] Description of Figure Numbers:

[0059] 100. Pole piece production line; 10. Extrusion film forming mechanism; 11. First shell; 111. First shell body; 1111. First main body; 1112. First limiting portion; 112. First non-metallic layer; 113. Extrusion chamber; 114. First feed port; 12. Extrusion piece; 121. Extrusion screw; 13. Tableting structure; 20. Composite mechanism; 21. Pressing roller; 22. Composite gap; 23. Thinning gap; 30. Kneading mechanism; 31. Second shell; 311. Second shell body; 3111. Second main body; 3112. Second limiting portion; 312. Third non-metallic layer; 313. Kneading chamber; 314. Second discharge port; 315. Opening; 32. Stirring blade; 33. Feed screw; 34. Cover;

[0060] 40. Material feeding mechanism; 50. Slurry feeding mechanism; 60. Drying mechanism; 70. Winding mechanism;

[0061] 1. Diaphragm; 2. Current collector; 3. Pole.

[0062] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0063] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0064] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), such directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0065] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0066] Energy conservation and emission reduction are key to the sustainable development of the automotive industry. Electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of the sustainable development of the automotive industry. For electric vehicles, battery technology is a key factor in their development.

[0067] The pole piece on a battery cell typically consists of a current collector and a diaphragm disposed on at least one side of the current collector. In related technologies, the diaphragm is produced by extrusion film forming. During this process, wear and tear between the moving parts of the extruder and the walls of the extruder cavity can produce metal particles. This can lead to excessive metal particles in the raw materials used to make the diaphragm, affecting battery performance and cycle life. Furthermore, if the extruder produces large metal particles during operation, this can also cause wear and tear on subsequent equipment.

[0068] Based on the above considerations, the present application proposes an extrusion film-forming mechanism, which includes a first shell, an extrusion piece and a pressing structure. An extrusion cavity and a first discharge port connected to the extrusion cavity are formed in the first shell. The first shell includes a first shell body and a first non-metallic layer covering the inner wall surface of the first shell body; the extrusion piece is movably arranged in the extrusion cavity, and the surface layer of the extrusion piece is provided with a second non-metallic layer. The extrusion piece is configured to extrude the slurry and deliver the slurry to the first discharge port; the pressing structure is provided at the first discharge port and is provided with a film-forming gap. The film-forming gap is configured to allow the slurry to pass through and be formed into a film.

[0069] The diaphragm of the electrode is prepared by the above-mentioned extrusion film-forming mechanism. Since a first non-metallic layer is set on the inner wall of the extrusion cavity of the extrusion film-forming mechanism, and a second non-metallic layer is set on the surface of the extrusion part used to extrude the slurry, this arrangement means that when the extrusion film-forming mechanism is running, even if mutual wear occurs between the extrusion part and the first shell, no metal particles will be generated, thereby avoiding the mixing of metal particles in the slurry for making the diaphragm, avoiding the metal particles of the diaphragm exceeding the standard, improving the quality of the electrode, and thus improving the safety, electrochemical performance and cycle life of the battery.

[0070] The pole pieces mentioned in the embodiments of the present application are applied to battery cells, which can be used in electrical devices that use batteries as power sources or various energy storage systems that use batteries as energy storage elements. Electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, battery-powered vehicles, electric cars, ships, spacecraft, and the like. Among them, electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, and the like.

[0071] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly can be a wound structure or a stacked structure. The electrode assembly typically includes a positive electrode sheet and a negative electrode sheet. The negative electrode sheet is the electrode that absorbs or lithiates lithium ions when the battery is charged and releases or delithiates lithium when the battery is discharged. The positive electrode sheet is the electrode that releases or delithiates lithium ions when the battery is charged and absorbs or lithiates lithium when the battery is discharged. The positive electrode sheet includes a positive electrode current collector and a positive electrode membrane disposed on at least one side of the positive electrode current collector. The positive electrode membrane includes a positive electrode active material. The negative electrode sheet includes a negative electrode current collector and a negative electrode membrane disposed on at least one side of the negative electrode current collector. The negative electrode membrane includes a negative electrode active material.

[0072] The membrane on the electrode is typically formed by extrusion, where a slurry is extruded into a membrane. The slurry is a mixture of materials and slurry raw materials. The materials can be, but are not limited to, positive / negative active material, conductive agent, positive / negative solid binder, or a mixture of two or more. The slurry raw material can be a liquid binder or a mixture of a liquid binder and other materials. Optionally, the membrane extruded by the extrusion can be thinned by a rolling mechanism to achieve the desired membrane thickness.

[0073] The present application proposes an extrusion film forming mechanism 10, which includes a first shell 11, an extrusion member 12 and a pressing structure 13. An extrusion cavity 113 and a first discharge port connected to the extrusion cavity 113 are formed in the first shell 11. The first shell 11 includes a first shell body 111 and a first non-metallic layer 112 covering the inner wall surface of the first shell body 111; the extrusion member 12 is movably arranged in the extrusion cavity 113, and the surface layer of the extrusion member 12 is provided with a second non-metallic layer. The extrusion member 12 is configured to extrude slurry and deliver the slurry to the first discharge port; the pressing structure 13 is provided at the first discharge port and is provided with a film forming gap. The film forming gap is configured to allow the slurry to pass through and be formed into a membrane 1.

[0074] Specifically, the first housing 11 includes a first housing body 111 serving as a base structure and a first non-metallic layer 112 disposed on the inner wall of the first housing body 111. The first housing body 111 can be made of a high-strength metal material, such as alloy steel or titanium alloy. The first non-metallic layer 112 covers the inner wall of the first housing body 111 and forms the wall of the extrusion cavity 113. The first non-metallic layer 112 can be made of, but not limited to, ceramic, plastic, or phenolic resin. For example, wear-resistant engineering plastics such as polytetrafluoroethylene (POM), polyetheretherketone (PEEK), and polytetrafluoroethylene can be used as the first non-metallic layer 112. This arrangement prevents metal particles from being mixed into the slurry due to wear on the inner wall of the first housing 11 during the slurry extrusion process, resulting in excessive metal particle content in the prepared diaphragm 1. This improves the performance of the final electrode 3 and battery cell, thereby increasing the cycle life of the battery cell.

[0075] A tabletting structure 13 is provided at the discharge port of the first housing 11. The tabletting structure 13 can be configured as a mold structure having a flat channel or at least a flat opening, or, as in the following embodiment, can include two rollers disposed opposite each other, forming a film-forming gap between the two rollers. When the slurry passes through the film-forming gap, it is molded into a film 1. Providing two rollers allows the two rollers to rotate when the slurry passes through the film-forming gap, thereby reducing friction between the slurry and the tabletting structure 13 and ensuring that the slurry remains stable during the extrusion process.

[0076] The extrusion member 12 is used to extrude and stir the slurry in the extrusion chamber 113 and transport the slurry to the discharge port and the tableting structure 13, so that the slurry passes through the film-forming gap of the tableting structure 13 to form the diaphragm 1, and then is discharged outward. The extrusion member 12 can be configured as a screw, a plunger, or other structure, which is not limited here.

[0077] In the embodiment of the present application, a second non-metallic layer is provided on the surface of the extruded member 12. The second non-metallic layer can be made of an inorganic non-metallic material, such as, but not limited to, a ceramic coating, a carbon-based material coating, a tungsten carbide coating, a silicon nitride coating, and an aluminum nitride coating. This arrangement can prevent metal particles from being mixed into the slurry due to wear on the surface of the extruded member 12 during the slurry extrusion process, resulting in an excessive metal particle content in the prepared diaphragm 1. This improves the performance of the final electrode 3 and battery cell, and is conducive to increasing the cycle life of the battery cell.

[0078] In one embodiment, the material of the first non-metallic layer 112 is set to be engineering plastic.

[0079] Engineering plastics have excellent overall structural performance, including good rigidity, wear resistance, corrosion resistance, structural strength, and high hardness. For example, the first non-metallic layer 112 can be made of, but not limited to, one or more engineering plastics such as polyamide (PA), polycarbonate (PC), polyoxymethylene (POM, Sigang), polyester (PBT, PET), polyphenylene oxide (PPO), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyimide (PI), and polytetrafluoroethylene (PTFE). These materials all have good rigidity, wear resistance, corrosion resistance, and high structural strength and hardness. As a result, the first non-metallic layer 112 has high rigidity and structural strength, good wear resistance, high pressure bearing capacity, and is not easily abraded.

[0080] In one embodiment, the second non-metallic layer is made of an inorganic non-metallic material.

[0081] Inorganic non-metallic materials have high hardness, wear resistance, and corrosion resistance. Inorganic non-metallic materials can be, but are not limited to, ceramics, carbon-based materials, carbides, nitrides, oxides, borides, and the like. For example, the second non-metallic layer can include at least one of a ceramic coating, a carbon-based coating, a tungsten carbide coating, a silicon nitride coating, an aluminum nitride coating, an aluminum oxide coating, and a zirconium oxide coating. The use of the above materials to form the second non-metallic layer on the surface of the extrusion 12 provides the extrusion 12 with excellent wear resistance and corrosion resistance, as well as high structural strength and resistance to wear.

[0082] In one embodiment, the first shell body 111 includes a first main body portion 1111 and a first limiting portion 1112. The first main body portion 1111 is provided with an extrusion cavity 113, and a first feed port 114 and a first discharge port connected to the extrusion cavity 113. The first limiting portion 1112 is protruded from the inner side of the first feed port 114. The first non-metallic layer 112 is adhered to the inner wall of the first main body portion 1111 and abuts against the first limiting portion 1112.

[0083] In this embodiment, the first main body 1111 of the first shell body 111 serves as a base structure, and is provided with an extrusion cavity 113 and a first feed port 114 and a first discharge port connected to the extrusion cavity 113. The first feed port 114 can be used to place the slurry into the extrusion cavity 113, wherein, by protruding a first limiting portion 1112 on the inner side of the first feed port 114 and limiting the first non-metallic layer 112 by using the first limiting portion 1112, the first non-metallic layer 112 can be prevented from escaping from the first feed port 114, thereby improving the overall structural stability of the first shell 11.

[0084] Optionally, the first limiting portion 1112 may be arranged around the circumference of the first feed port 114 , or one, two or more first limiting portions 1112 may be arranged on the inner side of the first feed port 114 , which is not limited here.

[0085] In one embodiment, the thickness of the first non-metallic layer 112 is set to 10 mm to 20 mm.

[0086] In this embodiment, the thickness of the first non-metallic layer 112 can be set to 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, or any value between 10mm and 20mm. This setting method enables the first non-metallic layer 112 to have a better pressure-bearing capacity. In addition, since the extrusion cavity 113 has size requirements, it is necessary to have sufficient space for accommodating the extrusion part 12 and the slurry, and it is also necessary to ensure the structural strength of the first shell body 111. It is necessary to avoid the wall thickness of the first shell body 111 being too thin. By setting the thickness of the first non-metallic layer 112 to no more than 20mm, it is possible to avoid the size of the first shell 11 being too large, or the wall thickness of the first shell body 111 being too thin to affect the structural strength.

[0087] In one embodiment, the first shell body 111 and the first non-metallic layer 112 are bonded together.

[0088] In this embodiment, the first shell body 111 and the first non-metallic layer 112 can be bonded together using an adhesive such as epoxy resin glue, two-liquid mixed hardening glue (AB glue), etc. In this setting, the first shell body 111 and the first non-metallic layer 112 are easy to assemble and have a high connection strength.

[0089] In one embodiment, the extrusion member 12 includes two extrusion screws 121 arranged side by side. The extrusion screws 121 are rotatable, and the surface of the extrusion screws 121 is provided with a second non-metallic layer.

[0090] In this embodiment, the extrusion film forming mechanism 10 is configured as a twin-screw extrusion mechanism, including two extrusion screws 121 arranged side by side. The extrusion screw 121 can be configured as a conical screw. In the direction close to the discharge port, the diameter of the extrusion screw 121 is gradually reduced. When the extrusion film forming mechanism 10 is running, the two extrusion screws 121 rotate synchronously to extrude the slurry, mix the slurry thoroughly, and send the slurry to the discharge port to form a membrane 1 through the film forming gap of the sheeting structure 13. The twin-screw extrusion mechanism has a strong extrusion capacity and can better squeeze the voids in the slurry and drive the material into the space occupied by the voids, so that a slurry with uniform uniformity can be obtained, so that the formed membrane 1 has good lateral consistency, which is conducive to controlling the thickness and uniformity of the membrane 1.

[0091] In one embodiment, the first shell body 111 includes a material guide section and an extrusion section. The material guide section is located above the extrusion section. The material guide section is provided with a material guide channel that is gradually tapered from top to bottom. A first material feed port 114 is provided at the top of the material guide section. The extrusion section is provided with an extrusion cavity 113. The first non-metallic layer 112 is attached to the inner walls of the material guide section and the extrusion section.

[0092] In this embodiment, the material guiding channel that is gradually tapered in the material guiding section can enable the extrusion film forming mechanism 10 to have a larger first material feed port 114 , and can also enable the material to fall accurately into the extrusion cavity 113 .

[0093] In one embodiment, the sheeting structure 13 includes rollers arranged opposite to each other, and a film-forming gap is formed between the two rollers.

[0094] With this arrangement, the roller can rotate during the process of the slurry being extruded from the film-forming gap to form a film, thereby reducing the friction between the slurry and the tableting structure 13 and ensuring that the material can maintain a stable state during the extrusion process, thereby preventing the material from sagging or deviating from the predetermined track.

[0095] The present application also proposes a pole piece production line 100, including an extrusion film forming mechanism 10 and a composite mechanism 20. The specific structure of the extrusion film forming mechanism 10 refers to any of the aforementioned embodiments. The composite mechanism 20 is arranged downstream of the extrusion film forming mechanism 10. The composite mechanism 20 is configured to composite the membrane 1 with the current collector 2 to form a pole piece 3.

[0096] The electrode production line 100 proposed in this application adopts the extrusion film forming mechanism 10 in the aforementioned embodiment to prepare the diaphragm 1, and composites the diaphragm 1 and the current collector 2 into the electrode 3 through the composite mechanism 20. Since the cavity wall of the first shell 11 in the extrusion film forming mechanism 10 is covered with a first non-metallic layer 112, and the surface of the extrusion part 12 is provided with a second non-metallic layer, the generation of metal particles during the extrusion film forming process can be avoided, thereby avoiding the mixing of metal particles into the slurry for making the diaphragm 1, avoiding the metal particles in the diaphragm 1 from exceeding the standard, improving the quality of the electrode 3, and thus improving the safety, electrochemical performance and cycle life of the battery. Since this electrode production line 100 adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0097] In one embodiment, the electrode production line 100 also includes a kneading mechanism 30, a stirring blade 32 and a feeding screw 33. The kneading mechanism 30 is arranged upstream of the extrusion film forming mechanism 10. The kneading mechanism 30 includes a second shell 31. The second shell 31 is provided with a kneading cavity 313 and a second discharge port 314 connected to the kneading cavity 313. The second shell 31 includes a second shell body 311 and a third non-metallic layer 312 covering the inner wall of the second shell body 311; the stirring blade 32 is movably provided in the kneading cavity 313, and the stirring blade 32 is configured to stir the mixed material; one end of the feeding screw 33 is arranged toward the second discharge port 314, and the surface of the stirring blade 32 and the feeding screw 33 is provided with a fourth non-metallic layer.

[0098] In this arrangement, the material and slurry raw materials can be stirred and mixed by the stirring blades 32 in the kneading chamber 313 of the second shell 31 to form a slurry for extrusion film formation, which is then delivered to the discharge port by the feeding screw 33 for delivery to the extrusion film forming mechanism 10. This arrangement allows the slurry to be mixed more evenly. The material can be, but is not limited to, a mixture of one or more of the following: positive electrode active material / negative electrode active material, a conductive agent, a positive electrode solid binder / negative electrode solid binder; the slurry raw material can be a liquid binder or a mixture of a liquid binder and other materials.

[0099] In this embodiment, a third non-metallic layer 312 is provided on the inner wall of the second shell 31, and a fourth non-metallic layer is provided on the surface of the stirring blade 32 and the feeding screw 33. This can avoid the generation of metal particles due to wear of the second shell 31, the stirring blade 32 and the feeding screw 33 during the operation of the kneading mechanism 30, thereby avoiding the mixing of metal particles into the slurry for making the diaphragm 1, avoiding the metal particles of the diaphragm 1 from exceeding the standard, improving the performance of the electrode 3, and thus improving the safety, electrochemical performance and cycle life of the battery.

[0100] The third non-metallic layer 312 may be made of, but not limited to, ceramics, plastics, phenolic resins, and other materials. For example, engineering plastics with good wear resistance may be used as the third non-metallic layer 312, such as polytetrafluoroethylene (POM), polyetheretherketone (PEEK), and polytetrafluoroethylene.

[0101] The fourth non-metallic layer can be made of an inorganic non-metallic material, for example, it can be set to but not limited to a ceramic coating, a carbon-based material coating, a tungsten carbide coating, a silicon nitride coating, and an aluminum nitride coating.

[0102] Optionally, the fourth non-metallic layer provided on the surface of the stirring blade 32 and the fourth non-metallic layer provided on the surface of the feeding screw 33 may be made of the same material or different materials, which is not limited here.

[0103] In one embodiment, the third non-metal layer 312 is made of engineering plastic.

[0104] Engineering plastics have good overall structural performance, with good rigidity, wear resistance, corrosion resistance, structural strength and high hardness. For example, the third non-metallic layer 312 can be made of, but not limited to, one or more engineering plastics such as polyamide (PA), polycarbonate (PC), polyoxymethylene (POM, Saigang), polyester (PBT, PET), polyphenylene oxide (PPO), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyimide (PI), polytetrafluoroethylene (PTFE), etc. The above materials all have good rigidity, wear resistance, corrosion resistance, high structural strength and hardness, so that the third non-metallic layer 312 has high rigidity and structural strength, good wear resistance, high pressure bearing capacity, and is not easy to wear.

[0105] In one embodiment, the thickness of the third non-metallic layer 312 is set to 10 mm to 20 mm.

[0106] In this embodiment, the thickness of the third non-metallic layer 312 can be set to 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, or any value between 10mm and 20mm. This setting method enables the third non-metallic layer 312 to have a better pressure-bearing capacity. In addition, since the extrusion chamber 113 has size requirements, it is necessary to have sufficient space for accommodating structures such as the stirring blade 32 and the feed screw 33, and it is also necessary to ensure the structural strength of the second shell body 311. It is necessary to avoid the wall thickness of the second shell body 311 being too thin. By setting the thickness of the third non-metallic layer 312 to no more than 20mm, it is possible to avoid the size of the second shell 31 being too large or the wall thickness of the second shell body 311 being too thin, thereby affecting the structural strength.

[0107] In one embodiment, the fourth non-metal layer is made of an inorganic non-metal material.

[0108] Inorganic non-metallic materials have high hardness, wear resistance, and corrosion resistance, and include, but are not limited to, ceramics, carbon-based materials, carbide materials, nitride materials, oxide materials, and boride materials. For example, the fourth non-metallic layer may include at least one of a ceramic coating, a carbon-based material coating, a tungsten carbide coating, a silicon nitride coating, an aluminum nitride coating, an aluminum oxide coating, and a zirconium oxide coating. Using the above materials to form the fourth non-metallic layer on the surface of the extrusion 12 provides the extrusion 12 with excellent wear resistance and corrosion resistance, as well as high structural strength and resistance to wear.

[0109] In one embodiment, the second shell body 311 includes a second main body portion 3111 and a second limiting portion 3112. The second main body portion 3111 is provided with a kneading cavity 313, and an opening 315 and a second discharge port 314 connected to the kneading cavity 313. The second limiting portion 3112 is provided on the inner side of the opening 315. The third non-metallic layer 312 is attached to the inner wall of the second main body portion 3111 and abuts against the second limiting portion 3112.

[0110] In this embodiment, the main body of the second shell body 311 serves as a base structure, and is provided with a kneading cavity 313 and an opening 315 connected to the kneading cavity 313 and a second discharge port 314. The setting of the opening 315 facilitates the installation of components such as the stirring blade 32 and the feeding screw 33 in the kneading cavity 313. By protruding a second limiting portion 3112 on the inner side of the opening 315 and limiting the third non-metallic layer 312 by the second limiting portion 3112, the third non-metallic layer 312 can be prevented from escaping from the opening 315, thereby improving the overall structural stability of the second shell 31.

[0111] Optionally, the second limiting portion 3112 may be arranged around the circumference of the opening 315 , or one, two or more second limiting portions 3112 may be arranged on the inner side of the opening 315 , which is not limited here.

[0112] Optionally, the kneading mechanism 30 further includes a cover 34 covering the opening 315. When there is no need to disassemble or assemble components such as the stirring blades 32 and the feed screw 33, the cover 34 can prevent the kneading chamber 313 from being exposed, thereby preventing foreign matter from entering the kneading chamber 313. Optionally, the cover 34 is provided with a material feed port for supplying material into the kneading chamber 313 and a slurry feed port for supplying slurry raw materials into the kneading chamber 313.

[0113] In one embodiment, the second shell body 311 and the third non-metallic layer 312 are bonded together.

[0114] In this embodiment, the second shell body 311 and the third non-metallic layer 312 can be bonded together using an adhesive such as epoxy resin glue, two-liquid mixed hardening glue (AB glue), etc. In this setting, the second shell body 311 and the third non-metallic layer 312 are easy to assemble and have a high connection strength.

[0115] In one embodiment, the electrode production line 100 further includes a material feeding mechanism 40 for providing materials to the kneading mechanism 30 and a slurry feeding mechanism 50 for providing slurry raw materials, thereby eliminating the need for manual injection of slurry and materials into the kneading machine, thereby improving the degree of automation.

[0116] In one embodiment, the composite mechanism 20 includes a plurality of pressing rollers 21 , wherein a composite gap 22 for the membrane 1 and the current collector 2 to pass through is formed between two adjacent pressing rollers 21 .

[0117] In this embodiment, a plurality of pressing rollers 21 are provided in the composite mechanism 20, so that a composite gap 22 for composite the diaphragm 1 and the current collector 2 into one is formed between two adjacent pressing rollers 21. When the diaphragm 1 and the current collector 2 pass through the composite gap 22 at the same time, they are combined into one under the extrusion of the two pressing rollers 21 to form a pole piece 3. The two pressing rollers 21 can rotate to reduce the friction between the diaphragm 1 and the composite structure during the composite process, avoid the diaphragm 1 from being stretched and deformed, and improve the preparation yield and performance of the pole piece 3. Optionally, if it is necessary to composite the diaphragm 1 on both surfaces of the current collector 2, two sets of extrusion film forming mechanisms 10 can be provided, respectively located on both sides of the composite mechanism 20, and feed the composite mechanism 20 at the same time, so as to composite the diaphragm 1 on both surfaces of the current collector 2 at the same time, thereby improving the preparation efficiency.

[0118] Optionally, the composite mechanism 20 can be provided with three or more pressing rollers 21 to sequentially form a thinning gap 23 and a composite gap 22 along the feeding path. After the diaphragm 1 extruded from the extrusion film forming mechanism 10 enters the composite mechanism 20, it passes through the thinning gap 23 and the composite gap 22 in sequence. When passing through the thinning gap 23, the diaphragm 1 is thinned to adjust the thickness of the diaphragm 1. The thinned diaphragm 1 is then passed through the composite gap 22 to be composited with the current collector 2, thereby obtaining a pole piece 3 of the required thickness.

[0119] In some embodiments, the electrode production line 100 further includes a winding mechanism 70 , which is disposed downstream of the composite mechanism 20 . The winding mechanism 70 is used to wind the composite-formed electrode 3 into a coil for transportation and storage of the electrode 3 .

[0120] In some embodiments, the electrode production line 100 further includes a drying mechanism 60, which is disposed downstream of the composite mechanism 20. The provision of the drying mechanism 60 to dry the electrode 3 facilitates rapid evaporation of moisture from the electrode 3, allowing the electrode 3 to dry and set, thereby ensuring the performance of the electrode 3. Furthermore, the electrode 3 prepared in the electrode production line 100 can be transported by conveyor rollers, and a winding-type or folding-type drying oven can be used, thereby shortening the length of the oven, reducing the equipment footprint, and lowering production costs.

[0121] The present application also proposes a battery production line, including a pole piece production line 100 as described in any of the aforementioned embodiments. The specific structure of the pole piece production line 100 is similar to that of the aforementioned embodiments. Since the present battery production line adopts all the technical solutions of all the aforementioned embodiments, it has at least all the beneficial effects brought about by the technical solutions of the aforementioned embodiments, which will not be described in detail here.

[0122] The above description is merely an exemplary embodiment of the present application and does not limit the patent scope of the present application. Any equivalent structural transformation made using the contents of the present application specification and drawings under the technical concept of the present application, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present application.

Claims

1. An extrusion film forming mechanism, characterized in that: The extrusion film forming mechanism comprises: A first shell, wherein an extrusion cavity and a first discharge port communicating with the extrusion cavity are formed in the first shell, and the first shell includes a first shell body and a first non-metallic layer covering an inner wall surface of the first shell body; an extrusion member, the extrusion member being movably disposed in the extrusion cavity, the surface of the extrusion member being provided with a second non-metallic layer, the extrusion member being configured to extrude slurry and deliver the slurry to the first discharge port; and A sheet pressing structure is provided at the first discharge port and is provided with a film forming gap, wherein the film forming gap is configured to allow the slurry to pass through and be formed into a membrane.

2. The extrusion film forming mechanism according to claim 1, characterized in that: The material of the first non-metallic layer is set to be engineering plastic.

3. The extrusion film forming mechanism according to claim 1, wherein: The material of the second non-metallic layer is set to be an inorganic non-metallic material.

4. The extrusion film forming mechanism according to any one of claims 1 to 3, characterized in that: The first shell body includes a first main body portion and a first limiting portion, the first main body portion is provided with the extrusion cavity, and a first feed port and the first discharge port communicated with the extrusion cavity; the first limiting portion is protruded on the inner side of the first feed port, and the first non-metallic layer is attached to the inner wall of the first main body portion and abuts against the first limiting portion; And / or, the thickness of the first non-metallic layer is set to 10 mm to 20 mm; And / or, the first shell body and the first non-metallic layer are adhesively connected.

5. The extrusion film forming mechanism according to any one of claims 1 to 3, characterized in that: The extrusion piece includes two extrusion screws arranged side by side, the extrusion screws are rotatable, and the surface of the extrusion screws is provided with the second non-metallic layer; And / or, the sheet pressing structure includes rollers arranged opposite to each other, and the film forming gap is formed between two of the rollers.

6. A pole piece production line, characterized in that: include: The extrusion film forming mechanism according to any one of claims 1 to 5; and The composite mechanism is arranged downstream of the extrusion film forming mechanism, and is configured to composite the membrane and the current collector to form a pole piece.

7. The electrode production line according to claim 6, characterized in that: The electrode production line further includes a kneading mechanism, which is provided upstream of the extrusion film forming mechanism and includes: a second shell, the second shell being provided with a kneading cavity and a second discharge port communicating with the kneading cavity, the second shell comprising a second shell body and a third non-metallic layer covering an inner wall of the second shell body; A stirring blade, the stirring blade is movably provided in the kneading chamber, and the stirring blade is configured to stir the mixed material; and A feeding screw, one end of which is arranged toward the second discharge port, and a fourth non-metallic layer is provided on the surface of the stirring blade and the feeding screw.

8. The electrode production line according to claim 7, characterized in that: The material of the third non-metallic layer is set to engineering plastic; And / or, the material of the fourth non-metallic layer is set to be an inorganic non-metallic material.

9. The electrode production line according to claim 7, characterized in that: The second shell body includes a second main body portion and a second limiting portion, the second main body portion is provided with the kneading cavity, an opening communicating with the kneading cavity, and the second discharge port, the second limiting portion is provided on the inner side of the opening, and the third non-metallic layer is attached to the inner wall of the second main body portion and abuts against the second limiting portion; and / or, the third non-metallic layer is adhesively connected to the second shell body; And / or, the thickness of the third non-metallic layer is set to 10 mm to 20 mm.

10. The electrode production line according to any one of claims 6 to 9, characterized in that: The electrode production line further includes a drying mechanism, which is located downstream of the composite mechanism and is configured to dry the electrode; And / or, the electrode production line further includes a winding mechanism, which is located downstream of the composite mechanism and is configured to wind up the electrode.

11. A battery production line, characterized in that: Comprising a pole piece production line as described in any one of claims 6 to 10.

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