Pole piece manufacturing device

Abstract

The utility model discloses a pole piece manufacturing device which comprises a coating die head and a back roller, the back roller comprises a roller body, a containing cavity is formed in the roller body, and the containing cavity is used for containing a heat exchange medium. The coating die head and the back roller are oppositely arranged, a gap allowing a base material to penetrate through is formed between the coating die head and the back roller, and the coating die head is used for coating the surface of the base material with slurry. The temperature of the roller body is adjusted through the heat exchange medium, the interface consistency of the roller body can be improved, and therefore the coating consistency is improved.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and more particularly, to an electrode sheet manufacturing device. Background Art

[0002] With the development of new energy technologies, batteries are being used more and more widely. Batteries with high energy density, high safety, long service life, and environmental friendliness have been widely applied in passenger cars, commercial vehicles, electric bicycles, heavy trucks, energy storage facilities, battery swapping stations, engineering manufacturing, intelligent devices, etc. At the same time, they have also promoted technological development and research in areas such as communication terminals, medical devices, and energy development.

[0003] In battery technology, electrode sheets are usually prepared by coating. How to improve coating consistency is a technical problem that needs to be solved urgently. Summary of the Utility Model

[0004] An embodiment of this application provides an electrode sheet manufacturing device that can improve coating consistency.

[0005] In a first aspect, an embodiment of this application provides an electrode sheet manufacturing device, which includes a coating die head and a backing roller. The backing roller includes a roller body, and an accommodation cavity is formed inside the roller body for accommodating a heat exchange medium. The coating die head is disposed opposite to the backing roller, and a gap for the substrate to pass through is formed between the coating die head and the backing roller. The coating die head is used to coat a slurry on the surface of the substrate.

[0006] In the above technical solution, an accommodation cavity is formed inside the roller body for accommodating a heat exchange medium. The heat exchange medium can adjust the temperature of the roller body. When the roller body is heated, the heat exchange medium exchanges heat with the roller body to relieve the expansion of the roller body, or when the roller body is cooled, the heat exchange medium exchanges heat with the roller body to relieve the contraction of the roller body, improving the consistency of the roller surface and thus improving the coating consistency.

[0007] In some embodiments, along the axial direction of the roller body, from the middle to both ends of the roller body, the diameter of the accommodation cavity gradually decreases.

[0008] In the above technical solution, from the middle to both ends of the roller body, the diameter of the accommodation cavity gradually decreases. That is, the accommodation cavity is large in the middle and small at both ends, so that there is more heat exchange medium in the middle of the roller body, thereby improving the heat exchange efficiency in the middle of the roller body.

[0009] In some embodiments, the roller body includes a peripheral wall, a first end wall, and a second end wall. The first end wall and the second end wall are disposed opposite to each other along the circumferential direction of the roller body. The peripheral wall connects the first end wall and the second end wall, and the peripheral wall, the first end wall, and the second end wall together enclose the accommodation cavity.

[0010] In the above technical solution, the roller body has a hollow structure, which can obtain a relatively large accommodating cavity to accommodate more heat exchange medium, so as to improve the heat exchange efficiency and the adjustment efficiency of the temperature of the roller body.

[0011] In some embodiments, along the circumferential direction of the roller body, two ends of the peripheral wall respectively form a first opening and a second opening, the first end wall closes the first opening, and the second end wall closes the second opening.

[0012] In the above technical solution, the roller body is of a split structure, which reduces the preparation difficulty of the roller body.

[0013] In some embodiments, along the axial direction of the roller body, from the middle to both ends of the roller body, the wall thickness of the peripheral wall gradually increases.

[0014] In the above technical solution, since the degree of contraction or expansion in the middle of the peripheral wall is greater than that at both ends of the periphery, therefore, by making the middle of the peripheral wall thinner and both ends of the peripheral wall thicker, the heat exchange efficiency between the middle of the peripheral wall and the heat exchange medium is higher, which greatly alleviates the deformation in the middle of the peripheral wall, improves the consistency of the outer surface of the peripheral wall, and improves the coating consistency.

[0015] In some embodiments, the first end wall is provided with a medium inlet, the second end wall is provided with a medium outlet, and both the medium inlet and the medium outlet are communicated with the accommodating cavity.

[0016] In the above technical solution, by providing a medium inlet, it is convenient for the heat exchange medium to flow into the accommodating cavity, and by providing a medium outlet, it is convenient for the heat exchange medium to flow out of the accommodating cavity.

[0017] In some embodiments, the connecting line of the projections of the medium inlet and the medium outlet on a plane perpendicular to the axial direction of the roller body intersects with the central axis of the roller body.

[0018] In the above technical solution, along the radial direction of the roller body, the medium inlet and the medium outlet are located at two relatively far ends, which can improve the fluidity of the heat exchange medium, thereby balancing the temperature of the heat exchange medium everywhere and improving the temperature consistency of the roller body.

[0019] In some embodiments, the backup roll further includes a heating element, at least a part of the heating element is accommodated in the accommodating cavity, and the heating element is used to heat the heat exchange medium.

[0020] In the above technical solution, by providing a heating element, when the roller body is cooled, the heat exchange medium is heated to relieve the shrinkage of the roller body.

[0021] In some embodiments, the material of the roller body is steel.

[0022] In the above technical solution, a roller body with higher strength and better heat conduction efficiency can be obtained. Description of the Drawings

[0023] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0024] Figure 1 Schematic structural diagram of a pole piece manufacturing device according to some embodiments of the present application;

[0025] Figure 2 Schematic diagram of a perspective view of a substrate coating according to some embodiments of the present application;

[0026] Figure 3 Schematic diagram of another perspective view of a substrate coating according to some embodiments of the present application;

[0027] Figure 4 Schematic structural diagram of a back roll according to some embodiments of the present application;

[0028] Figure 5 Schematic diagram of the back roll expanding due to heat according to some embodiments of the present application;

[0029] Figure 6 Schematic diagram of the back roll contracting due to cold according to some embodiments of the present application;

[0030] Figure 7 Schematic structural diagram of a roll body according to some embodiments of the present application;

[0031] Figure 8 Schematic projection diagram of a medium inlet and a medium outlet according to some embodiments of the present application.

[0032] Icons: 1000 - Pole piece manufacturing device; 100 - Back roll; 10 - Roll body; 13 - Peripheral wall; 131 - First opening; 132 - Second opening; 133 - Inner surface; 134 - Outer surface; 11 - First end wall; 111 - Medium inlet; 12 - Second end wall; 121 - Medium outlet; 14 - Accommodation cavity; 20 - Heating element; 200 - Coating die head; 300 - Substrate; 400 - Coating layer.

[0033] The drawings are not drawn to actual scale. Detailed implementation manners

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts belong to the scope of protection of this application.

[0035] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the technical field to which this application belongs; the terms used in the description of this application in the specification are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the description and claims of this application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the description and claims of this application or the above drawings are used to distinguish different objects and are not used to describe a specific order or primary-secondary relationship.

[0036] Referring to "embodiments" in this application means that specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of this application. The appearance of this phrase in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments.

[0037] In the description of this application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "joined", and "attached" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0038] In the description of this application, it should be noted that unless otherwise stated, "a plurality of" means two or more; the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. is only for the convenience of describing this application and simplifying the description, rather than indicating or implying 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 to this application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable error range. "Parallel" is not strictly parallel, but within the allowable error range.

[0039] In this application, the term "and / or" is merely a description of the relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, in this application, the character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0040] In this application, the term "or" is merely a description of the relationship between associated objects, indicating that there can be two relationships. For example, A or B can represent: A exists alone, and B exists alone.

[0041] In the embodiments of this application, the same reference numerals represent the same components. And for the sake of brevity, in different embodiments, the detailed description of the same components is omitted. It should be understood that the thickness, length, width, etc. of various components in the embodiments of this application shown in the drawings, as well as the overall thickness, length, width, etc. of the integrated device, are only for illustrative purposes and should not constitute any limitation to this application.

[0042] The term "a plurality of" as used in this application refers to two or more (including two).

[0043] In this application, the battery cell may include, but is not limited to, lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, magnesium-ion batteries, etc. The battery cell includes, but is not limited to, cylinder shapes, flat shapes, cuboid shapes, or other shapes, etc. Generally, the battery cell includes cylindrical battery cells, square battery cells, pouch battery cells, etc. in terms of the encapsulation method.

[0044] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell mainly operates by the movement of metal ions between the positive electrode sheet and the negative electrode sheet. Metal ions (such as lithium ions) are embedded and extracted back and forth between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, which can prevent the short circuit between the positive electrode sheet and the negative electrode sheet, and at the same time allow active ions to pass through.

[0045] The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The positive electrode current collector without the coated positive electrode active material layer protrudes from the positive electrode current collector with the coated positive electrode active material layer. The positive electrode current collector without the coated positive electrode active material layer serves as the positive electrode tab.

[0046] Taking a lithium-ion battery as an example, the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, etc. The positive electrode current collector can be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, carbon electrode, carbon, nickel, or titanium, etc. can be used. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0047] The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The negative electrode current collector without the coated negative electrode active material layer protrudes from the negative electrode current collector with the coated negative electrode active material layer. The negative electrode current collector without the coated negative electrode active material layer serves as the negative electrode tab.

[0048] The negative electrode current collector can be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, carbon electrode, carbon, nickel, or titanium, etc. can be used. The negative electrode active material can be carbon or silicon, etc.

[0049] In order to ensure that no fusing occurs when passing a large current, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly can be a wound structure or a stacked structure.

[0050] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application can include a battery module or a battery pack, etc.

[0051] During the production process of the battery, through the cooperation of a coating die head and a back roll, the coating die head coats the slurry on the surface of the substrate to form a pole piece. According to the different slurry components, a positive electrode sheet and a negative electrode sheet can be prepared and formed.

[0052] The back roll is an important component in the pole piece manufacturing device, and the consistency of the roll surface has an important impact on the coating consistency. If the slurry temperature is too high, the back roll expands due to heat, and the roll surface bulges and deforms, which will lead to a reduction in the coating quality in the expansion area; if the slurry temperature is too low, the back roll contracts due to cold, and the roll surface sinks and deforms, which will lead to an increase in the coating quality in the expansion area.

[0053] In view of this, in order to solve the problem that the back roller expands due to heat or contracts due to cold, and the poor consistency of the roller surface leads to a decrease in coating consistency, the embodiments of the present application provide a technical solution. By forming a receiving cavity inside the back roller, the receiving cavity is used to accommodate a heat exchange medium to adjust the temperature of the back roller and prevent the back roller from deforming, thereby improving coating consistency.

[0054] The technical solution disclosed in the embodiments of the present application is applicable to, but not limited to, the preparation of electrode foils or other sheet materials.

[0055] Figure 1 It is a schematic structural diagram of an electrode foil manufacturing apparatus 1000 according to some embodiments of the present application; Figure 2 It is a schematic view of one perspective of coating a substrate 300 according to some embodiments of the present application; Figure 3 It is a schematic view of another perspective of coating a substrate 300 according to some embodiments of the present application.

[0056] Referring to Figure 1 and Figure 2 The embodiments of the present application provide an electrode foil manufacturing apparatus 1000. The electrode foil manufacturing apparatus 1000 includes a coating die head 200 and a back roller 100. The coating die head 200 is disposed opposite to the back roller 100, and a gap for the substrate 300 to pass through is formed between the coating die head 200 and the back roller 100. The coating die head 200 is used to coat a slurry on the surface of the substrate 300.

[0057] The coating die head 200 is responsible for uniformly coating the slurry on the substrate 300 to form a coating layer 400. The coating die head 200 is usually designed with a specific lip shape, and the lip is used to control the flow rate of the slurry, thereby controlling the coating thickness.

[0058] The back roller 100 can be used in cooperation with the coating die head 200. The back roller 100 is used to support the substrate 300 and help control the tension of the substrate 300 during the coating process.

[0059] The substrate 300 can be a positive current collector, and the substrate 300 can also be a negative current collector. The slurry can be coated in a gap to form a plurality of coating layers 400, thereby realizing one electrode foil outputting multiple electrode foils. One electrode foil outputting multiple electrode foils means that an electrode foil with a relatively wide thickness is slit into a plurality of sub-electrode foils with a smaller width. Exemplarily, in Figure 2 there are three coating layers 400, and one electrode foil outputs three electrode foils.

[0060] The gap A between the coating die head 200 and the back roller 100 determines the thickness of the coating layer 400. The larger the gap A, the thicker the coating layer 400 and the greater the coating weight; the smaller the gap A, the thinner the coating layer 400 and the smaller the coating weight. Therefore, the consistency of the roller surface of the back roller 100 will affect the consistency of the gap A, and further affect the coating consistency.

[0061] For convenience of description, in the following embodiments, the back roller 100 for pole piece coating is taken as an example for description.

[0062] Figure 4 FIG. 4 is a schematic structural diagram of the back roller 100 according to some embodiments of the present application; Figure 5 FIG. 6 is a schematic diagram of the back roller 100 expanding due to heat in some embodiments of the present application; Figure 6 FIG. 8 is a schematic diagram of the back roller 100 shrinking due to cold in some embodiments of the present application.

[0063] Referring to Figures 4 to 6 , an embodiment of the present application provides a back roller 100. The back roller 100 includes a roller body 10, and a receiving cavity 14 is formed inside the roller body 10. The receiving cavity 14 is used to receive a heat exchange medium.

[0064] The back roller 100 can be used in cooperation with a coating die head 200. The back roller 100 is used to support a substrate 300 and help control the tension of the substrate 300. The material of the back roller 100 may include, but is not limited to, steel, aluminum, ceramics, and their alloys, etc.

[0065] The receiving cavity 14 is a cavity formed inside the roller body 10. The receiving cavity 14 can be of any shape as long as it can receive the heat exchange medium.

[0066] The heat exchange medium is a fluid for adjusting the temperature of the roller body 10. Here, the fluid can be a liquid or a gas. Adjusting the temperature means heating or cooling the roller body 10. Optionally, the heat exchange medium can be circulated to achieve a better temperature adjustment effect. Optionally, the fluid can be water, a mixture of water and ethylene glycol, or air, etc.

[0067] Too high or too low slurry temperature will cause deformation of the roller surface of the back roller 100, affect the gap A between the back roller 100 and the coating die head 200, resulting in reduced coating consistency, reduced pole piece quality, and affecting the reliability and cycle life of the battery cell. Exemplarily, as Figure 5 shown, when the slurry temperature is too high, heat accumulates in the middle of the back roller 100, the temperature in the middle of the back roller 100 is relatively high and it expands, and the bulging degree in the middle of the back roller 100 is relatively high. This will cause the gap A between the middle of the back roller 100 and the coating die head 200 to decrease, and the thickness of the coating layer 400 corresponding to the middle of the back roller 100 to decrease. Exemplarily, as Figure 6 shown, when the slurry temperature is too cold, the temperature in the middle of the back roller 100 is relatively low, the middle of the back roller 100 shrinks, and the depression degree in the middle of the back roller 100 is relatively high. This will cause the gap A between the middle of the back roller 100 and the coating die head 200 to increase, and the thickness of the coating layer 400 corresponding to the middle of the back roller 100 to increase.

[0068] In this embodiment, an accommodation cavity 14 is formed inside the roller body 10, and the accommodation cavity 14 is used to accommodate a heat exchange medium. The heat exchange medium can adjust the temperature of the roller body 10. When the roller body 10 is heated, the heat exchange medium exchanges heat with the roller body 10 to relieve the expansion of the roller body 10, or when the roller body 10 is cooled, the heat exchange medium exchanges heat with the roller body 10 to relieve the contraction of the roller body 10, improving the roller surface consistency, thereby improving the coating consistency.

[0069] It can be understood that improving the roller surface consistency means reducing the risk of the roller surface bulging or denting and relieving the deformation of the roller surface. The roller surface is the outer peripheral surface surrounding the central axis of the roller body 10.

[0070] In some embodiments, along the axial direction of the roller body 10, from the middle of the roller body 10 to both ends, the diameter of the accommodation cavity 14 gradually decreases.

[0071] Understandably, along the axial direction of the roller body 10, the middle of the accommodation cavity 14 is large and the two ends are small.

[0072] Exemplarily, as Figure 4 shown, define the position C as the middle of the roller body 10, and the S direction as the direction from the middle of the roller body 10 to both ends. It should be understood that the C position is relative and a certain degree of deviation is allowed.

[0073] Since the degree of deformation is greater closer to the middle of the roller body 10 and smaller closer to both ends of the roller body 10. Therefore, from both ends of the roller body 10 to the middle of the roller body 10, the heat exchange efficiency needs to gradually increase.

[0074] In this embodiment, from the middle of the roller body 10 to both ends, the diameter of the accommodation cavity 14 gradually decreases. This enables the middle of the roller body 10 to have more heat exchange medium, thereby improving the heat exchange efficiency in the middle of the roller body 10 and thus improving the roller surface consistency.

[0075] Refer to Figure 4 , in some embodiments, the roller body 10 includes a peripheral wall 13, a first end wall 11, and a second end wall 12. The first end wall 11 and the second end wall 12 are oppositely arranged along the circumferential direction of the roller body 10. The peripheral wall 13 connects the first end wall 11 and the second end wall 12, and the peripheral wall 13, the first end wall 11, and the second end wall 12 together enclose to form the accommodation cavity 14.

[0076] The peripheral wall 13 can be understood as the wall portion surrounding the central axis of the roller body 10. The outer surface 134 of the peripheral wall 13 is the roller surface.

[0077] The first end wall 11 and the second end wall 12 can be understood as the wall portions located at both ends of the peripheral wall 13. In some embodiments, the first end wall 11 and the second end wall 12 can be connected to a rotating shaft (not shown in the figure) to enable the rotation of the backup roller 100.

[0078] The first end wall 11 and the second end wall 12 only need to be adapted to the shape of the peripheral wall 13. Exemplarily, the first end wall 11 and the second end wall 12 are configured as circular shapes.

[0079] The materials of the first end wall 11, the second end wall 12, and the peripheral wall 13 can be the same or different.

[0080] The first end portion, the second end wall 12, and the peripheral wall 13 can be integrally formed or separately prepared and then connected by means such as bonding or welding.

[0081] In this embodiment, the roller body 10 has a hollow structure, and a relatively large accommodation cavity 14 can be obtained to accommodate more heat exchange media, thereby improving the heat exchange efficiency, improving the adjustment efficiency of the temperature of the roller body 10, and improving the roller surface consistency.

[0082] Figure 7 It is a schematic structural diagram of the roller body 10 of some embodiments of the present application.

[0083] Refer to Figure 7 , in some embodiments, along the circumferential direction of the roller body 10, a first opening 131 and a second opening 132 are respectively formed at both ends of the peripheral wall 13. The first end wall 11 closes the first opening 131, and the second end wall 12 closes the second opening 132.

[0084] It can be understood that the peripheral wall 13 is a hollow cylindrical structure.

[0085] The shape of the first end wall 11 is suitable for the first opening 131, and the shape of the second end wall 12 is suitable for the second opening 132. Optionally, both the first opening 131 and the second opening 132 are circular, and both the first end wall 11 and the second end wall 12 are configured as circular plates.

[0086] The connection between the first end wall 11 and the peripheral wall 13 can be sealed by a sealing member (not shown in the figure). The connection between the second end wall 12 and the peripheral wall 13 can also be sealed by a sealing member.

[0087] In this embodiment, the roller body 10 has a split structure, which reduces the manufacturing difficulty of the roller body 10.

[0088] In some embodiments, along the axial direction of the roller body 10, from the middle of the roller body 10 to both ends, the wall thickness of the peripheral wall 13 gradually increases.

[0089] The peripheral wall 13 has an inner surface 133 facing the accommodation cavity 14 and an outer surface 134 facing away from the accommodation cavity 14. Along the radial direction of the roller body 10, the distance between the inner surface 133 and the outer surface 134 is the wall thickness of the peripheral wall 13. It can be understood that the middle of the peripheral wall 13 is thin and both ends are thick. The outer surface 134 of the peripheral wall 13 can be understood as the roller surface.

[0090] Since the degree of contraction or expansion in the middle of the peripheral wall 13 is greater than that at both ends of the peripheral wall 13, the middle of the peripheral wall 13 is thinner and both ends of the peripheral wall 13 are thicker. As a result, the heat exchange efficiency between the middle of the peripheral wall 13 and the heat exchange medium is higher, which can greatly alleviate the deformation in the middle of the peripheral wall 13, improve the interface consistency of the outer surface 134 of the peripheral wall 13, and improve the coating consistency.

[0091] In some embodiments, the first end wall 11 is provided with a medium inlet 111, and the second end wall 12 is provided with a medium outlet 121. Both the medium inlet 111 and the medium outlet 121 communicate with the accommodation cavity 14.

[0092] The medium inlet 111 can be an opening formed in the first end wall 11, or can also be a structure such as a water nozzle or a pipe body installed on the first end wall 11. Similarly, the medium outlet 121 can be an opening formed in the second end wall 12, or can also be a structure such as a water nozzle or a pipe body installed on the second end wall 12.

[0093] In other embodiments, the medium inlet 111 and the medium outlet 121 can be provided on the same end wall. For example, both the medium inlet 111 and the medium outlet 121 are provided on the first end wall 11, or both the medium inlet 111 and the medium outlet 121 are provided on the second end wall 12.

[0094] In this embodiment, by providing the medium inlet 111, it is convenient for the heat exchange medium to flow into the accommodation cavity 14, and by providing the medium outlet 121, it is convenient for the heat exchange medium to flow out of the accommodation cavity 14, realizing the circulation of the heat exchange medium. Moreover, the medium outlet 121 and the medium inlet 111 are arranged at two positions with a relatively large distance, which can improve the fluidity of the heat exchange medium, balance the temperature of the heat exchange medium everywhere, and improve the roll surface consistency.

[0095] Figure 8 It is a projection schematic diagram of the medium inlet 111 and the medium outlet 121 in some embodiments of the present application.

[0096] Refer to Figure 8 , in some embodiments, the connection line of the projections of the medium inlet 111 and the medium outlet 121 on the plane S perpendicular to the axial direction of the roller body 10 intersects with the central axis of the roller body 10.

[0097] Exemplarily, in Figure 8 , the plane perpendicular to the axial direction of the roller body 10 is defined as S, the projection of the medium inlet 111 on the plane S is defined as 111a, and the projection of the medium outlet 121 on the plane S is defined as 121a.

[0098] It can be understood that if the roller body 10 is cylindrical, the projection of the roller body 10 on the plane S perpendicular to the axial direction of the roller body 10 is circular, and the connection line of the projections of the medium inlet 111 and the medium outlet 121 passes through the center of the circle. At this time, this connection line can be understood as the diameter of the circle, and the projections of the medium inlet 111 and the medium outlet 121 are located at both ends of the diameter.

[0099] In this embodiment, along the radial direction of the roller body 10, the medium inlet 111 and the medium outlet 121 are located at the two relatively far ends, which can improve the fluidity of the heat exchange medium, thereby balancing the temperature of the heat exchange medium everywhere and improving the temperature consistency of the roller body 10.

[0100] Refer to Figure 4 , in some embodiments, the backing roller 100 further includes a heating element 20, at least a part of the heating element 20 is accommodated in the accommodation cavity 14, and the heating element 20 is used to heat the heat exchange medium.

[0101] The heating element 20 is a heating element for increasing the temperature of the heat exchange medium. The structural form of the heating element 20 includes but is not limited to heating tubes, heating wires, etc.

[0102] The heating element 20 can be configured to heat the heat exchange medium when the temperature of the slurry is lower than the first threshold, and the first threshold can be set according to specific needs. Specifically, when designing, considering the tolerance range of the material of the roller body 10, the temperature at which the material begins to contract when it is cooled is selected as the first threshold.

[0103] Similarly, in the embodiment where the heat exchange medium is cooling water, it can be selected to circulate the cooling water when the temperature of the slurry is greater than the second threshold to cool the roller body 10.

[0104] In this embodiment, by providing the heating element 20, when the roller body 10 is cooled, the heat exchange medium is heated to relieve the contraction of the roller body 10.

[0105] Of course, in other embodiments, the heating element 20 may not be provided. For example, the heat exchange medium can be heated outside the backing roller 100 and then injected into the accommodation cavity 14.

[0106] In some embodiments, the material of the roller body 10 is steel, so that a roller body 10 with higher structural strength and higher heat conduction efficiency can be obtained.

[0107] The embodiment of the present application provides a polar plate manufacturing device 1000, and the polar plate manufacturing device 1000 includes the backing roller 100 provided in any one of the above.

[0108] In some embodiments, the electrode sheet manufacturing apparatus 1000 further includes a coating die head 200. The coating die head 200 is disposed opposite to the back roller 100. A gap for the substrate 300 to pass through is formed between the coating die head 200 and the back roller 100. The coating die head 200 is configured to coat a slurry on the surface of the substrate 300.

[0109] An embodiment of the present application provides an electrode sheet manufacturing apparatus 1000, which includes a back roller 100 and a coating die head 200. The back roller 100 is disposed opposite to the coating die head 200. A gap for the substrate 300 to pass through is formed between the back roller 100 and the coating die head 200. The coating die head 200 is configured to coat a slurry on the surface of the substrate 300. The back roller 100 is configured to tension the substrate 300. The back roller 100 includes a roller body 10 and a heating member 20. The roller body 10 is cylindrical. The roller body 10 includes a peripheral wall 13, a first end wall 11, and a second end wall 12. The first end wall 11 and the second end wall 12 are disposed opposite to each other along the circumferential direction of the roller body 10. The peripheral wall 13 connects the first end wall 11 and the second end wall 12. The peripheral wall 13, the first end wall 11, and the second end wall 12 together enclose an accommodation cavity 14. Along the circumferential direction of the roller body 10, a first opening 131 and a second opening 132 are respectively formed at both ends of the peripheral wall 13. The first end wall 11 closes the first opening 131, and the second end wall 12 closes the second opening 132. Along the axial direction of the roller body 10, from the middle to both ends of the roller body 10, the wall thickness of the peripheral wall 13 gradually increases. Along the axial direction of the roller body 10, from the middle to both ends of the roller body 10, the diameter of the accommodation cavity 14 gradually decreases. The peripheral wall 13 is a solid of revolution. The peripheral wall 13 has an inner surface 133 and an outer surface. The outer surface 134 is cylindrical, and the generatrix of the inner surface 133 is an arc. The material of the roller body 10 is steel. The accommodation cavity 14 is configured to accommodate cooling water. At least a part of the heating member 20 is accommodated in the accommodation cavity 14. The heating member 20 is configured to heat the cooling water when the temperature of the slurry is lower than a first threshold.

[0110] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other.

[0111] The above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. For those skilled in the art, various modifications and changes can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A pole piece manufacturing device, characterized in that: The pole piece manufacturing device comprises: A back roller, the back roller comprising a roller body, a receiving cavity is formed inside the roller body, and the receiving cavity is used to receive a heat exchange medium; The coating die head is arranged opposite to the backing roller, and a gap is formed between the coating die head and the backing roller for the substrate to pass through. The coating die head is used to coat the slurry onto the surface of the substrate.

2. The pole piece manufacturing device according to claim 1, characterized in that: Along the axial direction of the roller body, from the middle to both ends of the roller body, the diameter of the accommodating cavity gradually decreases.

3. The pole piece manufacturing device according to claim 1, characterized in that: The roller body includes a peripheral wall, a first end wall and a second end wall. The first end wall and the second end wall are arranged opposite to each other along the circumference of the roller body. The peripheral wall connects the first end wall and the second end wall. The peripheral wall, the first end wall and the second end wall together enclose the accommodating cavity.

4. The pole piece manufacturing device according to claim 3, characterized in that: Along the circumference of the roller body, two ends of the circumferential wall respectively form a first opening and a second opening, the first end wall closes the first opening, and the second end wall closes the second opening.

5. The pole piece manufacturing device according to claim 3, characterized in that: Along the axial direction of the roller body, from the middle to both ends of the roller body, the wall thickness of the peripheral wall gradually increases.

6. The pole piece manufacturing device according to claim 3, characterized in that: The first end wall is provided with a medium inlet, and the second end wall is provided with a medium outlet, and both the medium inlet and the medium outlet are communicated with the accommodating cavity.

7. The pole piece manufacturing device according to claim 6, characterized in that: A line connecting the projections of the medium inlet and the medium outlet on a plane perpendicular to the axial direction of the roller body intersects with the central axis of the roller body.

8. The pole piece manufacturing device according to any one of claims 1 to 7, characterized in that: The backing roller further includes a heating element, at least a portion of which is accommodated in the accommodating cavity, and the heating element is used to heat the heat exchange medium.

9. The pole piece manufacturing device according to any one of claims 1 to 7, characterized in that: The roller body is made of steel.

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