Coating die head, coating device and battery production equipment

Abstract

The utility model relates to a coating die head, a coating device and battery production equipment, and belongs to the technical field of batteries. The coating die head comprises a die head body and an electrode module, and the die head body comprises a containing cavity; and the electrode module is accommodated in the accommodating cavity and is configured to perform electrolytic removal on metal impurities in the slurry in the accommodating cavity. According to the coating die head, the coating device and the battery production equipment provided by the invention, the content of magnetic, weakly magnetic or micron-sized magnetic metal impurities in slurry is reduced, and the reliability of a formed battery is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a coating die head, a coating device and battery production equipment. Background Art

[0002] Coating is an essential process in lithium-ion battery production and a key step that directly impacts battery safety, capacity, lifespan, and other performance characteristics. Coating involves applying a prepared, viscous, paste-like slurry evenly, continuously, or intermittently onto a substrate (aluminum or copper foil). During the coating process, the thickness must be consistent across all coating locations and controlled within the tolerances required by the process.

[0003] The slurry of the related art contains magnetic or non-magnetic metal impurities, which affect the reliability of the battery after molding. Utility Model Content

[0004] In view of the above problems, the present application provides a coating die, a coating device and a battery production equipment, which can reduce the content of magnetic, weakly magnetic or micron-sized magnetic metal impurities in the slurry and improve the reliability of the battery after molding.

[0005] In a first aspect, an embodiment of the present application provides a coating die, which includes a die body and an electrode module, wherein the die body includes a receiving cavity; the electrode module is received in the receiving cavity, and the electrode module is configured to electrolytically remove metal impurities in the slurry in the receiving cavity.

[0006] In the technical solution of the embodiment of the present application, an electrode module is arranged in the accommodating cavity, so that when the coating die head is coating, the magnetic, weakly magnetic and non-magnetic metal impurities in the slurry can be first removed by electrolysis, thereby reducing the distribution of metal impurities in the slurry. After the coated electrode is made into a bare battery cell, the precipitation of anode metal impurities during charging and discharging can be reduced, and the risk of the precipitated dendritic metal impurities piercing the diaphragm between the electrode pieces and causing self-discharge abnormalities is reduced, thereby improving the reliability of the battery after formation.

[0007] In some embodiments, the electrode module includes a positive electrode body and a negative electrode body that are relatively spaced apart, and the positive electrode body and the negative electrode body are used to form a conductive path with the slurry. With this design, when the potential of the conductive path formed by the positive electrode body and the negative electrode body reaches the oxidation potential of the metal element, the metal element in the slurry can be oxidized and lose electrons, thereby forming metal ions with no physical self-discharge risk. These metal ions can combine with the hydroxide ions in the slurry to form chemically stable hydroxides, thereby improving the bare battery cell after forming, reducing the risk of metal ions being generated during subsequent cycles of the battery and precipitated on the anode sheet, causing damage to the diaphragm.

[0008] In some embodiments, the accommodating cavity is a cavity extending along a first direction; both the positive electrode body and the negative electrode body are rod-shaped structures extending along the first direction; or both the positive electrode body and the negative electrode body are spiral structures extending along the first direction. In this way, the rod-shaped positive and negative electrode bodies can increase the coverage of the electrode module in the first direction, allowing the conductive path formed by the electrode module to cover a larger portion of the accommodating cavity, thereby improving the removal rate of metal impurities in the slurry.

[0009] In some embodiments, the outer surfaces of both the positive and negative electrode bodies are provided with a plurality of protrusions, with at least some of the protrusions being spaced apart along the first direction. This design can further increase the contact area between the electrode module and the slurry, thereby increasing the probability of electrolytic oxidation of metal impurities in the slurry and improving the efficiency of the electrode module in electrolytically removing metal impurities in the slurry.

[0010] In some embodiments, both the positive and negative electrodes are titanium rods, stainless steel rods, iridium-tantalum-titanium rods, or ruthenium-iridium-titanium rods. This allows the positive and negative electrodes to have excellent electrical conductivity and corrosion resistance, as well as good electrochemical stability and mechanical workability. Furthermore, the dimensions of the positive or negative electrode can be designed based on the structure of the housing cavity, facilitating precise control of the electrolysis process and further improving the removal efficiency of metal impurities in the slurry.

[0011] In some embodiments, the spacing between the positive and negative electrodes is 5 mm to 20 mm, and the output voltage of the electrode module is 4 V to 100 V. With this design, the spacing between the positive and negative electrodes can be selected based on the actual conditions of the housing chamber to achieve good metal impurity removal efficiency while also being compatible with coating die heads of different sizes. Accordingly, the output voltage of the electrode module can also be selected based on the type of slurry so that the potential of the conductive path formed between the positive and negative electrodes reaches the oxidation potential of the metal impurities, thereby effectively removing the metal impurities in the slurry.

[0012] In some embodiments, the accommodating chamber includes at least two sub-cavities spaced apart along the second direction, with adjacent sub-cavities communicating with each other, and the second direction intersecting the first direction; the electrode module is disposed in at least one of the sub-cavities. By configuring the accommodating chamber to include at least two sub-cavities spaced apart along the second direction, with adjacent sub-cavities communicating with each other, the slurry, after being introduced from the outside into the coating die, must pass through the two sub-cavities sequentially before being coated onto the electrode piece. This improves the stability and uniformity of the slurry flow within the accommodating chamber, facilitating improved uniformity of subsequent slurry coating.

[0013] In some embodiments, the number of electrode modules matches the number of sub-cavities, with one electrode module corresponding to one sub-cavity. This design approach, i.e., providing multiple electrode modules, allows conductive pathways to be formed within different sub-cavities, allowing the slurry to flow through multiple conductive pathways in sequence within the holding cavity. This further improves the removal rate of metal impurities in the slurry and enhances the stability of the slurry applied by the coating die during charge and discharge.

[0014] In some embodiments, the die body further comprises a feed inlet and a discharge outlet, the feed inlet and the discharge outlet being disposed at opposite ends of the die body along the second direction; and the volume of each sub-cavity gradually decreases along the direction from the feed inlet to the discharge outlet. That is, as the slurry flows from the feed inlet to the discharge outlet, it sequentially passes through the multiple sub-cavities, and the volumes of the multiple sub-cavities gradually decrease. This allows the slurry to electrolytically remove metal impurities through the multiple electrode modules, and as the volumes of the sub-cavities gradually decrease, the electrode modules in different sub-cavities gradually cover a wider area of the slurry in the corresponding sub-cavity, thereby facilitating an overall removal rate of metal impurities in the slurry.

[0015] In some embodiments, the coating die further includes a heater disposed within the die body and configured to transfer heat to the accommodating cavity. By disposing the heater within the die body, the slurry within the accommodating cavity can be heated by the heater, thereby improving the electrode module's efficiency in electrolyzing metallic impurities in the slurry and enhancing the slurry's fluidity within the accommodating cavity.

[0016] In some embodiments, the heating element comprises a resistance wire. Using the resistance wire to electrically heat the receiving cavity simplifies the arrangement of the heating element, making it easier to evenly distribute the heating element around the periphery of the receiving cavity, thereby improving the uniformity of slurry heating at different locations in the receiving cavity.

[0017] In some embodiments, the heater is embedded within the die body and positioned around the periphery of the accommodating cavity. This design reduces the risk of direct contact between the heater and the slurry and allows the heater to be pre-embedded within the coating die during its formation, eliminating the need for mounting the heater on the die body and improving production efficiency.

[0018] In some embodiments, the die body comprises an upper die and a lower die, which cooperate to form a receiving cavity; the heating element is disposed within the upper die and / or the lower die. The separate design of the upper and lower dies not only reduces the difficulty of demolding during production, but also facilitates subsequent maintenance and replacement.

[0019] In a second aspect, an embodiment of the present application further provides a coating device, which includes a coating die head as provided in any of the aforementioned embodiments.

[0020] In a third aspect, an embodiment of the present application further provides a battery production device, which includes a coating device as provided in any of the aforementioned embodiments.

[0021] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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 these drawings without paying any creative work.

[0023] Figure 1 A schematic diagram of the three-dimensional structure of a coating die head provided in one embodiment of the present application;

[0024] Figure 2 for Figure 1 A cross-sectional view of the coating die shown along line AA;

[0025] Figure 3 A schematic diagram of the planar structure of a positive electrode or a negative electrode in a coating die head provided in one embodiment of the present application;

[0026] Figure 4 This is a schematic diagram of the planar structure of the positive electrode or negative electrode in a coating die head provided in another embodiment of the present application.

[0027] Explanation of the accompanying reference numerals: 100, coating die; 10, die body; 11, accommodating cavity; 111, sub-cavity; 12, feed port; 13, discharge port; 14, upper die; 15, lower die; 20, electrode module; 21, positive electrode body; 22, negative electrode body; 30, heating element; 101, protrusion; X, first direction; Y, second direction. DETAILED DESCRIPTION

[0028] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0029] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0030] In addition, if the term "and / or" appears, "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the objects associated with each other are in an "or" relationship. If the terms "first" and "second" appear, these terms are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "multiple" appears, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0031] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0032] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0033] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0034] Currently, market developments indicate that power batteries are becoming increasingly widely used. Power batteries are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric vehicles, as well as in aerospace and other fields. As power battery applications continue to expand, market demand is also growing.

[0035] Coating is the process of applying a thin layer of coating material in liquid or powder form to surfaces such as fabrics, paper, metal foil or plates. Coating is an essential step in the manufacturing process of battery cells.

[0036] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on a portion of the current collector's surface, and the portion of the current collector not coated with the positive active material layer serves as the positive tab. For lithium-ion batteries, for example, the positive current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet includes a negative current collector and a negative active material layer. The negative active material layer is coated on a portion of the current collector's surface, and the portion of the current collector not coated with the negative active material layer serves as the negative tab. The negative current collector can be made of copper, and the negative active material can be carbon or silicon, among others. To reduce the risk of melting due to high currents, multiple positive tabs are stacked, and multiple negative tabs are stacked.

[0037] In the production process of battery cells, the positive electrode active material is coated on the positive electrode current collector, and the negative electrode active material is coated on the negative electrode current collector by the coating process, that is, the prepared paste-like viscous slurry (positive electrode active material or negative electrode active material) is evenly, continuously or intermittently coated on the substrate (positive electrode current collector or negative electrode current collector). During coating, the thickness consistency of each coating position must be ensured, and the coating thickness must be controlled within the tolerance range required by the process.

[0038] In this regard, the inventors noticed that in the production and processing of batteries, the slurry usually needs to go through a demagnetization filtration process after preparation to remove large-particle metal impurities doped in the slurry. However, in this way, small, micro magnetic or non-magnetic metal impurities will still remain in the slurry. In this way, during the charge and discharge process of the battery cell made of such a slurry, the metal impurities will first be oxidized into ions on the cathode sheet, and then the metal ions will be shuttled to the diaphragm through the electrolyte, and finally precipitated on the anode sheet in the form of dendrites, which can easily cause damage to the diaphragm, and then cause abnormal self-discharge of the battery, affecting the long-term cycle and energy storage of the battery.

[0039] Based on the above content, an embodiment of the present application provides a coating die head, in which an electrode module is provided in the accommodating cavity of the coating die head. The slurry passed into the accommodating cavity is electrolyzed by the electrode module, and the metal impurities remaining in the slurry are electrolytically oxidized and removed, thereby reducing the risk of metal impurities precipitating on the anode sheet during the use of the battery, further removing small or micro metal impurities remaining in the slurry, and improving the reliability of battery processing.

[0040] Please refer to Figure 1 and Figure 2 An embodiment of the present application provides a coating die 100, which includes a die body 10 and an electrode module 20, wherein the die body 10 includes a accommodating cavity 11; the electrode module 20 is accommodated in the accommodating cavity 11, and the electrode module 20 is configured to electrolytically remove metal impurities in the slurry in the accommodating cavity 11.

[0041] The coating die 100 is a component located at the output end of the coating device and is the final component used to apply the slurry to the electrode. During the operation of the coating die 100, the slurry can continuously flow into the coating die 100 through the input end and be coated on the electrode through the output end of the coating die 100.

[0042] The die body 10 is the external structural component of the coating die 100, which is used to define the external structure and internal space structure of the coating die 100. Generally speaking, the input end of the die body 10 is the input end of the coating die 100, and is used to connect with the external slurry preparation component. The output end of the die body 10 is the output end of the coating die 100, and is used to evenly coat the slurry in the die body 10 onto the electrode.

[0043] The die body 10 includes a receiving cavity 11 , which means that a hollow cavity structure is designed in the die body 10 . It is understandable that the receiving cavity 11 needs to be connected to the aforementioned input end and output end to achieve uniform coating of the slurry.

[0044] The electrode module 20 is housed in the accommodating chamber 11 and is configured to electrolytically remove metal impurities from the slurry in the accommodating chamber 11. This means that the conductive portion of the electrode module 20 is disposed in the accommodating chamber 11 to contact the slurry in the accommodating chamber 11 and electrolytically remove metal impurities from the slurry.

[0045] The electrode module 20 may be a flat electrode, a spherical electrode, or a mesh electrode, so long as it can electrolytically oxidize the metal impurities in the slurry through electrical conduction. It is understood that in these embodiments of the present application, the material of the electrode module 20 should be an inert electrode material to reduce the content of metal impurities in the slurry.

[0046] The electrode module 20 can be detachably connected to the inner wall of the accommodating cavity 11 by means of snap-fitting, connecting with connectors (screws and bolts), etc., to facilitate subsequent replacement or maintenance; in some embodiments, the electrode module 20 can also be fixedly connected to the inner wall of the accommodating cavity 11 by welding or even integral molding to improve the structural consistency between the electrode module 20 and the die body 10.

[0047] In the technical solution of the embodiment of the present application, by arranging the electrode module 20 in the accommodating cavity 11, the coating die head 100 can first remove the magnetic, weakly magnetic and non-magnetic metal impurities in the slurry by electrolysis during coating, thereby reducing the distribution of metal impurities in the slurry. After the coated electrode is made into a bare battery cell, the precipitation of anode metal impurities during charging and discharging can be reduced, and the risk of the precipitated dendritic metal impurities piercing the diaphragm between the electrode pieces and causing self-discharge anomalies is reduced, thereby improving the reliability of the battery after formation.

[0048] It should be noted that the metal impurities may be, but are not limited to, Cu, Zn, Fe, Ni or stainless steel.

[0049] In some embodiments, the electrode module 20 includes a positive electrode body 21 and a negative electrode body 22 that are spaced apart from each other. The positive electrode body 21 and the negative electrode body 22 are used to form a conductive path with the slurry.

[0050] The electrode module 20 includes a positive electrode 21 and a negative electrode 22 that are spaced apart from each other. This means the electrode module 20 comprises two separate electrodes spaced apart from each other. One electrode is electrically connected to the positive electrode of an external power source, while the other is electrically connected to the negative electrode of the external power source. This allows the positive electrode 21 and the negative electrode 22 to form a conductive path with the slurry in the accommodating chamber 11, thereby electrolytically oxidizing and removing metal impurities in the slurry.

[0051] In these embodiments of the present application, in the initial stage of introducing the slurry into the containing cavity 11 of the coating die 100, the electrode module 20 can be controlled not to be energized. When the circulation of the slurry in the coating die 100 tends to be stable, the electrode module 20 is controlled to be energized, so that the electrode module 20 can cooperate with the slurry in the containing cavity 11 to form a conductive path and electrolyze and remove metal impurities in the slurry.

[0052] In these embodiments of the present application, when the potential of the conductive path formed by the positive electrode body 21 and the negative electrode body 22 reaches the oxidation potential of the metal impurities, the metal impurities in the slurry can be oxidized and lose electrons, thereby forming metal ions with no physical self-discharge risk. These metal ions can combine with the hydroxide ions in the slurry to form chemically stable hydroxides, thereby improving the bare battery cell after formation, reducing the risk of metal ions being generated during subsequent cycles of the battery, and precipitation on the anode sheet causing damage to the diaphragm.

[0053] Please refer to Figures 1 to 4 In some embodiments, the accommodating cavity 11 is a cavity extending along the first direction X; the positive electrode body 21 and the negative electrode body 22 are both rod-shaped structures extending along the first direction X; or, the positive electrode body 21 and the negative electrode body 22 are both spiral structures extending along the first direction X.

[0054] The accommodating cavity 11 is a cavity extending along the first direction X, wherein the first direction X can be set as a direction intersecting with the slurry discharge direction. In this way, after the external slurry enters the accommodating cavity 11 through the input end of the die body 10, it will first accumulate in the accommodating cavity 11 and flow along the first direction X to fill the accommodating cavity 11. In this way, the width, thickness and other parameters of the slurry coated on the electrode can be adjusted by controlling the shape of the output end of the die body 10.

[0055] The positive electrode body 21 and the negative electrode body 22 are both rod-shaped structures or spiral structures extending along the first direction X, which means that the positive electrode body 21 and the negative electrode body 22 are both extended along the first direction X in the accommodating cavity 11, so that when the slurry flows in the accommodating cavity 11, the conductive channel formed by the positive electrode body 21 and the negative electrode body 22 can cover most of the slurry, thereby improving the removal rate of metal impurities in the slurry.

[0056] Among them, the positive electrode body 21 and the negative electrode body 22 are both spiral structures extending along the first direction X, which means that the positive electrode body 21 and the negative electrode body 22 can be set in a manner similar to a linear spring. By designing the positive electrode body 21 and the negative electrode body 22 as spiral structures, the positive electrode body 21 and the negative electrode body 22 can obtain a larger contact area with the slurry under the same width size of the accommodating cavity 11, which is beneficial to improving the electrolytic removal efficiency of metal impurities.

[0057] In some embodiments, a plurality of protrusions 101 are disposed on the outer surfaces of the positive electrode body 21 and the negative electrode body 22 , and at least some of the protrusions 101 are disposed at intervals along the first direction X on the outer surfaces of the positive electrode body 21 and the negative electrode body 22 .

[0058] The outer surfaces of the positive electrode body 21 and the negative electrode body 22 are both provided with a plurality of protrusions 101 , which are intended to further increase the contact area between the positive electrode body 21 or the negative electrode body 22 and the slurry through such protrusions 101 and further improve the electrolytic removal efficiency of metal impurities in the slurry.

[0059] In these embodiments of the present application, the protrusion 101 may be a semicircular, semi-elliptical, or rectangular protrusion 101 protruding outward from the outer surface of the positive electrode body 21 or the negative electrode body 22 .

[0060] At least some of the protrusions 101 are arranged at intervals along the first direction X on the outer surfaces of the positive electrode body 21 and the negative electrode body 22, which means that the protrusions 101 can be evenly arranged along the first direction X to evenly increase the contact area between the positive electrode body 21 or the negative electrode body 22 and the slurry at each position in the first direction X, thereby improving the overall removal efficiency of metal impurities in the slurry.

[0061] For example, taking the positive electrode body 21 as a rod-shaped structure, a plurality of protrusions 101 can be provided and evenly spaced along the circumference of the positive electrode body 21 to form a row of protrusions 101. At the same time, along the first direction X, a plurality of the aforementioned rows of protrusions 101 are provided on the outer surface of the positive electrode body 21, thereby increasing the contact area with the slurry at each position in the first direction X. This can increase the probability of electrolytic oxidation of metal impurities in the slurry, and can also improve the efficiency of electrolytic removal of metal impurities in the slurry by the electrode module 20.

[0062] In some embodiments, both the positive electrode 21 and the negative electrode 22 are titanium rods, stainless steel rods, iridium-tantalum-titanium rods, or ruthenium-iridium-titanium rods. This means that the material of the positive electrode 21 can be, but is not limited to, titanium, stainless steel, iridium-tantalum-titanium, or ruthenium-iridium-titanium, and the material of the negative electrode 22 can also be, but is not limited to, titanium, stainless steel, iridium-tantalum-titanium, or ruthenium-iridium-titanium.

[0063] In these embodiments of the present application, materials such as titanium, stainless steel, iridium-tantalum-titanium or ruthenium-iridium-titanium all have good resistance to chemical corrosion and good electrical conductivity. In the system for electrolysis of metal impurities in the slurry, they can be used as inert electrolysis to obtain good electrical conductivity without undergoing electrochemical reactions themselves.

[0064] According to the coating die head 100 provided in the embodiment of the present application, the positive electrode body 21 and the negative electrode body 22 can have good electrical conductivity and corrosion resistance while also having good electrochemical stability and mechanical machinability. The structural dimensions of the positive electrode body 21 or the negative electrode body 22 can then be designed according to the structure of the accommodating cavity 11, which is conducive to the precise control of the electrolysis process and further improves the efficiency of removing metal impurities in the slurry.

[0065] In some embodiments, the distance between the positive electrode body 21 and the negative electrode body 22 is 5 mm to 20 mm; and the output voltage of the electrode module 20 is 4V to 100V.

[0066] With this design, the spacing between the positive electrode body 21 and the negative electrode body 22 can be selected according to the actual situation of the accommodating cavity 11 to obtain good metal impurity removal efficiency while adapting to coating dies 100 of different sizes.

[0067] For example, in these embodiments of the present application, the spacing between the positive electrode body 21 and the negative electrode body 22 can be set to 6 mm, 8 mm, 10 mm, 12 mm, 14 mm, 16 mm, 18 mm, or 19 mm. The above can be freely selected based on the dimensional parameters of the coating die head 100 and the receiving chamber 11 so that the positive electrode body 21 and the negative electrode body 22 can form a conductive path with the slurry.

[0068] The output voltage of the electrode module 20 can also be selected according to the type of slurry so that the potential of the conductive path formed between the positive electrode body 21 and the negative electrode body 22 reaches the oxidation potential of the metal impurities, thereby removing the metal impurities in the slurry.

[0069] For example, the output voltage of the electrode module 20 may be set to 5V, 10V, 30V, 50V, 80V, 90V, or 95V.

[0070] In some embodiments, the accommodating cavity 11 includes at least two sub-cavities 111 spaced apart along the second direction Y, adjacent sub-cavities 111 are connected, and the second direction Y intersects the first direction X; the electrode module 20 is disposed in at least one of the sub-cavities 111 .

[0071] The accommodating chamber 11 includes at least two sub-cavities 111, and adjacent sub-cavities 111 are connected, wherein the second direction Y can be set as the direction of slurry flow in the accommodating chamber 11. In other words, the accommodating chamber 11 includes at least two interconnected sub-cavities 111, and each sub-cavity 111 is arranged sequentially along the flow direction of the slurry, so that the slurry needs to pass through each sub-cavity 111 in sequence before it can be coated at the output end of the die body 10. In this way, the sub-cavities 111 arranged along the second direction Y can be used to improve the stability and uniformity of the slurry flow in the accommodating chamber 11, which is conducive to improving the uniformity of subsequent slurry coating.

[0072] The electrode module 20 is set in at least one of the sub-cavities 111, which means that the setting position of the electrode module 20 can be at least one of the multiple sub-cavities 111, that is, the slurry needs to undergo at least one electrolysis before being coated through the coating die 100 to reduce the content of metal impurities in the slurry.

[0073] In some embodiments, the number of electrode modules 20 matches the number of sub-cavities 111 , and one electrode module 20 is correspondingly disposed to one sub-cavity 111 .

[0074] In these embodiments of the present application, the number of electrode modules 20 matches the number of sub-cavities 111, and one electrode module 20 is arranged corresponding to one sub-cavity 111, that is, an electrode module 20 is provided in each sub-cavity 111, so that the slurry needs to undergo electrolysis when passing through different sub-cavities 111, which can further improve the removal rate of metal impurities in the slurry by the coating die head 100.

[0075] For example, in some embodiments of the present application, the number of sub-cavities 111 can be set to two, then the number of electrode modules 20 should also be two, and the two electrode modules 20 are respectively arranged in the two sub-cavities 111 to electrolytically remove metal impurities in the two sub-cavities 111 respectively.

[0076] This design can form conductive paths in different sub-cavities 111 respectively, so that the slurry can pass through multiple conductive paths in sequence when flowing in the containing cavity 11, thereby further improving the removal rate of metal impurities in the slurry, and making the slurry coated by the coating die 100 more stable during charging and discharging.

[0077] In some embodiments, the die body 10 further includes a feed port 12 and a discharge port 13, which are arranged at both ends of the die body 10 along the second direction Y; along the direction from the feed port 12 to the discharge port 13, the volume of each sub-cavity 111 gradually decreases.

[0078] The feed port 12 and the discharge port 13 are respectively the input end and the output end of the aforementioned die body 10, wherein the feed port 12 is used to connect with the external slurry supply component so that the slurry can flow into the accommodating cavity 11, and the discharge port 13 is the structure for the slurry to flow out of the accommodating cavity 11 and be coated on the electrode.

[0079] The feed port 12 and the discharge port 13 are arranged at both ends of the die body 10 along the second direction Y, that is, the slurry flows along the second direction Y in the accommodating cavity 11, flows into the accommodating cavity 11 from the feed port 12 of the die body 10, and flows out from the discharge port 13 of the die body 10.

[0080] Along the direction from the feed port 12 to the discharge port 13, the volume of each sub-cavity 111 gradually decreases, that is, the slurry flows into different sub-cavities 111 in turn along the flow direction, and the volume of each sub-cavity 111 gradually decreases. In this way, the slurry first undergoes an electrolytic oxidation to remove metal impurities in the sub-cavity 111 with a larger volume, and then passes into the sub-cavity 111 with a smaller volume. Since the volume of the sub-cavity 111 is smaller, the electrode module 20 can cover a larger proportion of the slurry in the sub-cavity 111, and then perform at least one fine electrolytic removal of metal impurities, thereby further improving the overall electrolytic removal rate of metal impurities in the slurry.

[0081] In these embodiments of the present application, the volume ratio between adjacent sub-cavities 111 can be set to 2:1. At the same time, the volume ratio between adjacent sub-cavities 111 can be selected according to parameters such as the flow rate of the slurry in the containing cavity 11 and the overall usage.

[0082] In some embodiments, the coating die 100 further includes a heating element 30 , which is disposed on the die body 10 and is used to transfer heat to the accommodating cavity 11 .

[0083] The function of the heating element 30 is to heat the slurry in the accommodating chamber 11 so that the slurry has better flowability, and can assist the electrode module 20 to improve the electrolytic removal efficiency of metal impurities in the slurry.

[0084] In these embodiments of the present application, the heating element 30 can be arranged in the feed port 12 or in the accommodating chamber 11 , as long as the heating element 30 can release heat to the slurry in the accommodating chamber 11 .

[0085] In some embodiments, the heating element 30 comprises a resistance wire. Using the resistance wire to electrically heat the receiving chamber 11 simplifies the arrangement of the heating element 30 , making it easier to evenly distribute the heating element 30 around the periphery of the receiving chamber 11 , thereby improving the uniformity of slurry heating at different locations within the receiving chamber 11 .

[0086] In some embodiments, the heating element 30 is embedded in the die body 10 and disposed on the periphery of the accommodating cavity 11 .

[0087] The heating element 30 is embedded in the die body 10 , which means that the heating element 30 can be pre-buried in the die body 10 when the die body 10 is formed. After the die body 10 is formed, the heating element 30 can transfer heat to the accommodating cavity 11 through the structure of the die body 10 .

[0088] Such a design can reduce the risk of direct contact between the heating element 30 and the slurry, and eliminate the installation process of the heating element 30 and the die body 10 , which is beneficial to improving the production efficiency of the coating die 100 .

[0089] The heating element 30 is arranged on the periphery of the accommodating cavity 11. A possible implementation method is that during the molding stage of the die body 10, the heating part of the heating element 30 is pre-buried in the mold cavity of the mold and arranged close to the location of the accommodating cavity 11. In this way, after the die body 10 is molded, the heating element 30 can be embedded in the die body 10 and arranged along the periphery of the accommodating cavity 11, and then the heating element 30 can be used to uniformly heat various positions of the accommodating cavity 11.

[0090] In some embodiments, the die body 10 includes an upper die 14 and a lower die 15 , which cooperate to form a receiving cavity 11 ; the heating element 30 is disposed in the upper die 14 and / or the lower die 15 .

[0091] In these embodiments of the present application, the die body 10 is a split structure, that is, the upper die 14 and the lower die 15 are formed separately and then assembled to form the die body 10 , and the upper die 14 and the lower die 15 cooperate to form the accommodating cavity 11 .

[0092] The heating element 30 can be embedded in the upper die head 14 and the lower die head 15 respectively, and then after the upper die head 14 and the lower die head 15 jointly form the die head body 10, heat can be transferred to the accommodating cavity 11 from all directions of the accommodating cavity 11, further improving the uniformity of the heating element 30 heating the slurry in the accommodating cavity 11.

[0093] In these embodiments of the present application, three groups of control experiments were conducted on metal impurities with a diameter of less than or equal to 50 microns and metal impurities with a diameter between 50 microns and 100 microns in the slurry, respectively. The experimental results are as follows:

[0094] The same batch of slurry was collected three times to form three experimental groups. Metal impurities were removed from the three experimental groups using the coating die head 100 provided in the embodiment of the present application under the experimental condition of being powered at 40° C. for 1 minute.

[0095] Among them, the mass of Cu with a diameter of less than or equal to 50 μm in the first group of slurries before electrolysis was 0.1011 g, the mass after electrolysis was 0.0999, and the electrolysis efficiency was 98.8%.

[0096] The mass of Cu with a diameter of less than or equal to 50 μm in the second group of slurries before electrolysis was 0.1017 g, and the mass after electrolysis was 0.1009 g, with an electrolysis efficiency of 99.2%.

[0097] In the third group of slurries, the mass of Cu with a diameter of less than or equal to 50 μm before electrolysis was 0.1014 g, the mass after electrolysis was 0.1001, and the electrolysis efficiency was 98.7%.

[0098] In the first group of slurries, the mass of Cu with a diameter between 50 μm and 100 μm before electrolysis was 0.1021 g, the mass after electrolysis was 0.0931 g, and the electrolysis efficiency was 91.2%.

[0099] In the second group of slurries, the mass of Cu with a diameter between 50 μm and 100 μm before electrolysis was 0.1012 g, the mass after electrolysis was 0.0924 g, and the electrolysis efficiency was 91.3%.

[0100] In the third group of slurries, the mass of Cu with a diameter between 50 μm and 100 μm before electrolysis was 0.1009 g, the mass after electrolysis was 0.0917 g, and the electrolysis efficiency was 90.9%.

[0101] Based on the above experimental results, when the coating die head 100 provided in the embodiment of the present application is energized at 40°C for 1 minute, the average electrolysis efficiency for Cu with a diameter less than or equal to 50 microns in the slurry is 98.9%, and the average electrolysis efficiency for Cu with a diameter between 50 microns and 100 microns in the slurry is 91.1%, which can remove most of the Cu metal impurities in the slurry.

[0102] Furthermore, in order to verify the effect of temperature on the removal efficiency of metal impurities in the slurry, a control experiment was also conducted in the present embodiment. The experimental conditions and results are as follows:

[0103] Three samples of the same batch of slurry were collected to form three experimental groups. In each experimental group, two slurry samples were electrolyzed at 25°C and 40°C respectively. The residual Cu with a diameter of less than or equal to 50 microns in the slurry after electrolysis was used as the detection object to determine the electrolysis efficiency of the coating die 100 at 25°C and 40°C. The experimental results are as follows:

[0104] Group 1: The electrolysis efficiency was 64.30% at a temperature of 25°C, and 98.80% at a temperature of 40°C.

[0105] The second group: The electrolysis efficiency was 66.80% at a temperature of 25°C, and the electrolysis efficiency was 99.10% at a temperature of 40°C.

[0106] The third group: The electrolysis efficiency was 68.70% at a temperature of 25°C, and the electrolysis efficiency was 99.20% at a temperature of 40°C.

[0107] It can be seen from this that the average electrolysis efficiency of the coating die head 100 provided in the embodiment of the present application is 66.60% at a temperature of 25°C, and the average electrolysis efficiency at a temperature of 25°C is 99.03%. It can be concluded that the heating element 30 can greatly improve the removal efficiency of metal impurities in the slurry.

[0108] An embodiment of the present application further provides a coating device, which includes a coating die head 100 as provided in any of the aforementioned embodiments.

[0109] An embodiment of the present application further provides a battery production device, which includes a coating device as provided in any of the aforementioned embodiments.

[0110] According to some embodiments of this application, please refer to Figures 1 to 4 An embodiment of the present application provides a coating die 100, which includes a die body 10, an electrode module 20 and a heating element 30, wherein the die body 10 includes a accommodating cavity 11; the electrode module 20 is accommodated in the accommodating cavity 11, and the electrode module 20 is configured to electrolytically remove metal impurities in the slurry in the accommodating cavity 11.

[0111] The electrode module 20 includes a positive electrode body 21 and a negative electrode body 22 that are spaced apart from each other. The positive electrode body 21 and the negative electrode body 22 are used to form a conductive path with the slurry. In these embodiments of the present application, during the initial stage of introducing the slurry into the receiving chamber 11 of the coating die head 100, the electrode module 20 can be controlled to be de-energized. After the flow of the slurry in the coating die head 100 becomes stable, the electrode module 20 is controlled to be energized, thereby enabling the electrode module 20 to form a conductive path with the slurry in the receiving chamber 11 and electrolytically remove metal impurities in the slurry.

[0112] In some embodiments, the positive electrode body 21 and the negative electrode body 22 may both be rod-shaped structures extending along the first direction X; or, the positive electrode body 21 and the negative electrode body 22 may both be spiral structures extending along the first direction X. This design allows the positive electrode body 21 and the negative electrode body 22 to obtain a larger contact area with the slurry while maintaining the same width of the accommodating cavity 11, thereby facilitating improved electrolytic removal efficiency of metal impurities.

[0113] In some embodiments, the heating element 30 can be embedded in the die body 10 and arranged on the periphery of the accommodating cavity 11. This design can reduce the risk of direct contact between the heating element 30 and the slurry, and eliminates the installation process of the heating element 30 and the die body 10, which is beneficial to improving the production efficiency of the coating die 100.

[0114] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0115] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A coating die head, characterized in that, include: The die body includes a receiving cavity; The electrode module is accommodated in the accommodating cavity, and is configured to electrolytically remove metal impurities in the slurry in the accommodating cavity.

2. The coating die head according to claim 1, characterized in that The electrode module includes a positive electrode body and a negative electrode body that are spaced apart from each other. The positive electrode body and the negative electrode body are used to cooperate with the slurry to form a conductive path.

3. The coating die head according to claim 2, characterized in that The accommodating cavity is a cavity extending along the first direction; The positive electrode body and the negative electrode body are both rod-shaped structures extending along the first direction; or the positive electrode body and the negative electrode body are both spiral structures extending along the first direction.

4. The coating die head according to claim 3, characterized in that A plurality of protrusions are provided on the outer surfaces of the positive electrode body and the negative electrode body, and at least some of the protrusions are provided on the outer surfaces of the positive electrode body and the negative electrode body at intervals along the first direction.

5. The coating die head according to claim 3, characterized in that The positive electrode body and the negative electrode body are both titanium rods, stainless steel rods, iridium tantalum titanium rods or ruthenium iridium titanium rods.

6. The coating die head according to claim 2, characterized in that The distance between the positive electrode body and the negative electrode body is 5mm to 20mm; The output voltage of the electrode module is 4V to 100V.

7. The coating die head according to claim 1, characterized in that The accommodating cavity includes at least two sub-cavities spaced apart along a second direction, adjacent sub-cavities are connected, and the second direction intersects the first direction; The electrode module is disposed in at least one of the sub-cavities.

8. The coating die head according to claim 7, characterized in that The number of the electrode modules matches the number of the sub-cavities, and one electrode module is correspondingly arranged to one sub-cavity.

9. The coating die head according to claim 7, characterized in that The die body further comprises a feed port and a discharge port, wherein the feed port and the discharge port are arranged at two ends of the die body along the second direction; Along the direction from the feed port to the discharge port, the volume of each sub-cavity gradually decreases.

10. The coating die head according to any one of claims 1 to 9, characterized in that: The coating die also includes a heating element, which is arranged on the die body and is used to transfer heat to the accommodating cavity.

11. The coating die head according to claim 10, characterized in that The heating element includes a resistance wire.

12. The coating die head according to claim 10, characterized in that The heating element is embedded in the die body and arranged on the periphery of the accommodating cavity.

13. The coating die head according to claim 12, characterized in that The die body comprises an upper die and a lower die, and the upper die and the lower die cooperate to form the accommodating cavity; The heating element is arranged in the upper die head and / or the lower die head.

14. A coating device, characterized in that: Comprising the coating die head according to any one of claims 1 to 13.

15. A battery production device, characterized in that: Comprising the coating device as claimed in claim 14.

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