Coating die head and pole piece coating device

Abstract

The utility model provides a coating die head and a pole piece coating device, a first coating gasket in the coating die head comprises a first coating opening, at least one of a first baffle and a third baffle and a second baffle are arranged at an interval, and a second coating gasket is clamped between a second die head and a third die head. And a channel defined by the second coating gasket comprises a necking section of which the size in the first direction is gradually reduced along the direction far away from the second coating opening. As the gap between the second baffle and at least one of the first baffle and the third baffle is larger than the gap between the second baffle and the first coating opening, more slurry flows to the first coating opening, and the edge of the slurry layer corresponding to the necking section in the first direction is thinner; the thickness of different slurry layers at different positions in the first direction is changed, so that the thickness distribution of different slurry layers coated on the pole piece is more reasonable, and the dynamic performance of the pole piece is improved.

Description

Technical Field

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

[0002] Batteries have the advantages of high specific energy and high power density. They are widely used in electronic devices and transportation vehicles, such as mobile phones, laptops, electric vehicles, electric airplanes, electric ships, electric tools, etc.

[0003] As an important process in the battery production process, the coating process has a very important impact on the quality of the battery. How to improve the coating process to improve the dynamic performance of the battery has always been an important research direction for those skilled in the art. Utility Model Content

[0004] In view of the above problems, the present application provides a coating die and a coating device for a pole piece. The coating die can make the thickness distribution of different slurry layers coated on the pole piece more reasonable, which is beneficial to improving the dynamic performance of the pole piece.

[0005] In a first aspect, some embodiments of the present application provide a coating die, which comprises a first die, a second die, a third die, a first coating gasket and a second coating gasket, wherein the second die is arranged opposite to the first die; the third die is arranged between the first die and the second die; the first coating gasket is sandwiched between the first die and the third die, the first coating gasket comprises a first baffle, a second baffle and a third baffle arranged along a first direction, the first die, the third die, the first baffle and the third baffle define a first coating port, and the second The baffle is spaced apart from the first coating port, and in the first direction, at least one of the first baffle and the third baffle is spaced apart from the second baffle; the second coating gasket is sandwiched between the second die head and the third die head, and the second coating gasket includes a fourth baffle and a fifth baffle arranged along the first direction, and the second die head, the third die head, the fourth baffle and the fifth baffle define the second coating port and a channel connected to the second coating port, and the channel includes a necking section connected to the second coating port, and the size of the necking section in the first direction gradually decreases in the direction away from the second coating port.

[0006] Since the second baffle is spaced apart from the first coating port, and at least one of the first baffle and the third baffle is spaced apart from the second baffle in the first direction, more slurry flows toward the first coating port through the gap between the second baffle and at least one of the first baffle and the third baffle than through the gap between the second baffle and the first coating port, so that the slurry layer of the pole piece corresponding to the gap between the second baffle and at least one of the first baffle and the third baffle in the first direction is thicker; since the size of the contraction section of the channel in the first direction gradually decreases in the direction away from the second coating port, the edge of the slurry layer corresponding to the contraction section in the first direction is thinner, so that the thickness of different slurry layers at different positions in the first direction is variable, so that the thickness distribution of different slurry layers applied on the pole piece is more reasonable, and the change of components in various parts of the entire slurry layer can be achieved, which is beneficial to improving the dynamic performance of the pole piece.

[0007] According to the coating die provided in some embodiments of the present application, the second coating gasket is provided with a second notch located between the fourth baffle and the fifth baffle, the second notch includes a notch area and an open area connected to the notch area, the open area is connected between the notch area and the second coating port, and the size of the open area in the first direction gradually decreases in the direction away from the second coating port to form a necking section, so that in the process of the slurry flowing from the channel formed by the notch area through the channel formed by the open area and flowing out from the second coating port, the thickness of the slurry layer corresponding to the channel part whose size increases in the first direction will be smaller than the thickness of the slurry layer in other parts, so that the thickness of the slurry layer corresponding to the notch area is greater than the thickness of the slurry layer corresponding to the open area, so that the thickness of the slurry layer is no longer consistent, thereby realizing the change of the thickness of the slurry layer in the first direction, which is conducive to making the thickness distribution of the slurry layer more reasonable.

[0008] According to the coating die provided in some embodiments of the present application, when observed along the second direction, the second baffle overlaps with the notch area in the first direction, and the second direction is perpendicular to the first direction, so that the area of ​​the slurry layer corresponding to the notch area can be stacked on the area of ​​the slurry layer corresponding to the second baffle, which is beneficial to keep the thickness of the overall slurry layer unchanged and is not easy to change the overall dimensional parameters of the electrode.

[0009] According to the coating die provided by some embodiments of the present application, in the first direction, the maximum dimension of the open area extending out of the notch area is L1, and the maximum dimension of the open area in the direction away from the second coating port is L2, 8mm≤L1≤20mm, 15mm≤L2≤35mm. This not only ensures that the edge portion of the slurry layer formed by the slurry flowing out of the second coating port has a sufficient thinning area so as to change the thickness of the slurry layer corresponding to the second coating port in the first direction, but also prevents the dimension of the open area extending out in the first direction from being too large. At the same time, the flow rate of the slurry can be slowed down in the process of flowing to the necking section to significantly reduce the thickness of the formed slurry layer, so that the slurry can be more smoothly filled in the area where the open area extends out of the notch area in the first direction, which is beneficial to reduce the possibility of coating leakage.

[0010] According to the coating die provided in some embodiments of the present application, the open area is configured as a trapezoid, which not only expands the flow area of ​​the slurry when it flows from the channel formed by the notch area into the channel formed by the open area, but also enables the open area to well connect the notch area and the second coating port.

[0011] According to the coating die provided in some embodiments of the present application, the first coating gasket is provided with a first notch, the first notch includes a flow reduction zone and a flow-through zone connected to the flow reduction zone on a side away from the first coating port, the flow reduction zone is connected to the first coating port, at least one of the first baffle and the third baffle is spaced apart from the second baffle through the flow-through zone, and the second baffle is spaced apart from the first coating port through the flow reduction zone.

[0012] By disposing at least one of the first baffle and the third baffle through the flow zone and the second baffle, and the second baffle is disposed through the flow reduction zone and the first coating port, the second baffle can play a certain blocking role on the flow of the slurry, and the flow zone is connected to the edge of the second baffle through the flow reduction zone, so that when the slurry flows from the flow zone to the first coating port, the slurry will flow into the flow reduction zone, the flow area of ​​the slurry can be expanded, and the flow rate is slowed down, so that the slurry layer corresponding to the flow reduction zone is thinner.

[0013] According to the coating die provided in some embodiments of the present application, when observed along the second direction, the flow area and the open area are aligned in the first direction, and the second direction is perpendicular to the first direction, so that the flow area and the open area correspond to each other, so that the area of ​​the slurry layer corresponding to the flow area outside the second baffle can be stacked on the area of ​​the slurry layer corresponding to the open area, which is beneficial to keep the thickness of the overall slurry layer unchanged and is not easy to change the overall dimensional parameters of the electrode.

[0014] According to the coating die provided in some embodiments of the present application, the dimension of the flow reduction zone in the direction away from the first coating port is L, L≥8mm, so that there is enough space between the second baffle and the first coating port for the slurry to flow into, so that the space between the second baffle and the first coating port can be smoothly filled with slurry, which is beneficial to reduce the possibility of missing the slurry flowing out of the first coating port.

[0015] According to the coating die provided in some embodiments of the present application, two flow zones are provided, and the second baffle is arranged on both sides of the first direction through the flow zone and is spaced apart from the first baffle and the third baffle, and the flow reduction zone is connected between the two flow zones, so that the thickness of the edge areas on both sides of the slurry layer corresponding to the first coating port can be changed.

[0016] According to the coating die provided in some embodiments of the present application, the first coating gasket also includes a first main plate, the first baffle, the second baffle and the third baffle are all connected to the first main plate, the thickness of the second baffle is H1, the thickness of the first main plate is H2, 0.3H2≤H1≤0.7H2, so that the second baffle can partially block the slurry from flowing into the first notch, thereby making it difficult for the slurry flowing out of the first coating port in the flow reduction zone to be interrupted, which is beneficial to reduce the possibility of coating leakage.

[0017] According to the coating die provided in some embodiments of the present application, the third die is provided with a first channel, the first channel is connected to the first coating port, the surface of the second baffle plate facing the first die is flush with the surface of the first main body plate facing the first die, so that there is a gap between the surface of the second baffle plate facing the third die and the third die, so that the slurry flowing into the first channel can flow into the flow reduction zone through the gap, and then the slurry flowing out of the first coating port in the flow reduction zone is not easily interrupted, which is beneficial to reduce the possibility of coating leakage.

[0018] According to the coating die provided in some embodiments of the present application, the second die is provided with a second channel, and the second channel is connected to the second coating port through a necking section, so that the slurry transported by the second die through the second channel can flow out from the first coating port through the necking section.

[0019] According to the coating die provided in some embodiments of the present application, the second baffle is configured as a rectangle, so that the second baffle has a good blocking effect on the slurry flowing out of the first channel, which is beneficial to improving the thinning effect of the second baffle on the slurry layer.

[0020] In a second aspect, some embodiments of the present application provide a coating device for a pole piece, which comprises a coating die head provided by any of the above-mentioned technical solutions, and the coating die head is used to coat slurry onto the surface of the pole piece.

[0021] The technical solution provided by the embodiments of the present disclosure brings at least the following beneficial effects:

[0022] The present application provides a coating die, which comprises a first die, a second die, a third die, a first coating gasket and a second coating gasket, the second die is arranged opposite to the first die, the third die is arranged between the first die and the second die, the first coating gasket is sandwiched between the first die and the third die, the first coating gasket comprises a first baffle, a second baffle and a third baffle arranged along a first direction, the first die, the third die, the first baffle and the third baffle define a first coating port, the second baffle is arranged spaced apart from the first coating port, in the first direction, at least one of the first baffle and the third baffle is spaced apart from the second baffle, the second coating gasket is sandwiched between the second die and the third die, the second coating gasket comprises a fourth baffle and a fifth baffle arranged along the first direction, the second die, the third die, the fourth baffle and the fifth baffle define a second coating port and a channel connected to the second coating port, the channel comprises a necking section, and the size of the necking section in the first direction gradually decreases along the direction away from the second coating port. Since the second baffle is spaced apart from the first coating port, and at least one of the first baffle and the third baffle is spaced apart from the second baffle in the first direction, more slurry flows toward the first coating port through the gap between the second baffle and at least one of the first baffle and the third baffle than through the gap between the second baffle and the first coating port, so that the slurry layer of the pole piece corresponding to the gap between the second baffle and at least one of the first baffle and the third baffle in the first direction is thicker; since the size of the contraction section of the channel in the first direction gradually decreases in the direction away from the second coating port, the edge of the slurry layer corresponding to the contraction section in the first direction is thinner, so that the thickness of different slurry layers at different positions in the first direction is variable, so that the thickness distribution of different slurry layers applied on the pole piece is more reasonable, and the change of components in various parts of the entire slurry layer can be achieved, which is beneficial to improving the dynamic performance of the pole piece.

[0023] 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

[0024] By reading the detailed description of the preferred embodiment below, various other advantages and benefits will become clear to those of ordinary skill in the art. The accompanying drawings are only used for the purpose of illustrating the preferred embodiment and are not considered to be limitations of the present application. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings.

[0025] Figure 1 A cross-sectional view of a coating die provided in some embodiments of the present application;

[0026] Figure 2A schematic diagram of the structure of a second coating gasket provided in some embodiments of the present application;

[0027] Figure 3 A schematic diagram of the structure of a first coating gasket provided in some embodiments of the present application;

[0028] Figure 4 Schematic diagram of the thickness distribution of the slurry layer corresponding to the first coated gasket and the second coated gasket in some embodiments of the present application.

[0029] In the attached picture:

[0030] 1. First die; 2. Second die; 21. Second channel; 3. Third die; 31. First channel; 4. First coating gasket; 41. First baffle; 42. Second baffle; 43. Third baffle; 44. First notch; 441. Flow reduction zone; 442. Overflow zone; 45. First main body plate; 451. First connecting hole; 5. First coating port; 6. Second coating gasket; 61. Fourth baffle; 62. Fifth baffle; 63. Second notch; 631. Notch zone; 632. Open zone; 64. Second main body plate; 641. Second connecting hole; 7. Second coating port; 8. Narrowing section; X, first direction; Y, second direction. DETAILED DESCRIPTION

[0031] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0032] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the embodiments of the present application should have the common meanings understood by technicians in the field to which the embodiments of the present application belong.

[0033] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0034] In addition, the technical terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0035] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like 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 a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0036] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature 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. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0037] At present, judging from the development of the market situation, the application of batteries is becoming more and more extensive. Batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields.

[0038] Coating is an essential process in the battery production process. The coating process has a very important impact on the quality of the battery and is a key process that directly affects the safety, capacity, life and other performance indicators of the battery. Coating is a method of coating a paste polymer, a molten polymer or a polymer melt on paper, cloth or plastic film to obtain a composite material (film). In the coating process of the pole piece, the coating die coats the slurry on the surface of the pole piece to give the pole piece good dynamic performance.

[0039] In the related art, when coating the pole piece with a coating die head, a double-layer coating method is sometimes used to form different slurry layers on the pole piece so that the pole piece can obtain better dynamic performance. However, the thickness of the slurry layer formed by this solution is consistent at all locations, making the components of the entire slurry layer consistent at all locations, which is not reasonable. Lithium deposition and other problems are prone to occur at the edge of the pole piece, which is not conducive to improving the dynamic performance of the pole piece.

[0040] In order to make the thickness distribution of different slurry layers coated on the pole piece more reasonable so as to improve the dynamic performance of the pole piece, an embodiment of the present application provides a coating die head, which includes a first die head, a second die head, a third die head, a first coating gasket and a second coating gasket, the second die head is arranged opposite to the first die head, the third die head is arranged between the first die head and the second die head, the first coating gasket is clamped between the first die head and the third die head, the first coating gasket includes a first baffle, a second baffle and a third baffle arranged along a first direction, the first die head, the third die head, the first baffle and the third baffle are arranged along a first direction, and the first die head, the third die head, the first baffle and the third baffle are arranged along a first direction. The three baffles define a first coating port, the second baffle is spaced apart from the first coating port, in the first direction, at least one of the first baffle and the third baffle is spaced apart from the second baffle, the second coating gasket is sandwiched between the second die head and the third die head, the second coating gasket includes a fourth baffle and a fifth baffle arranged along the first direction, the second die head, the third die head, the fourth baffle and the fifth baffle define a second coating port and a channel connected to the second coating port, the channel includes a necking section connected to the second coating port, and the size of the necking section in the first direction gradually decreases in the direction away from the second coating port. Since the second baffle is spaced apart from the first coating port, and at least one of the first baffle and the third baffle is spaced apart from the second baffle in the first direction, more slurry flows toward the first coating port through the gap between the second baffle and at least one of the first baffle and the third baffle than through the gap between the second baffle and the first coating port, so that the slurry layer of the pole piece corresponding to the gap between the second baffle and at least one of the first baffle and the third baffle in the first direction is thicker; since the size of the narrowing section of the channel in the first direction gradually decreases from the second coating port in the direction away from the second coating port, the edge of the slurry layer corresponding to the narrowing section in the first direction is thinner, so that the thickness of different slurry layers at different positions in the first direction is variable, so that the thickness distribution of different slurry layers applied on the pole piece is more reasonable, and the change of components in various parts of the entire slurry layer can be achieved, which is beneficial to improving the dynamic performance of the pole piece.

[0041] The coating die head disclosed in the embodiment of the present application can be used for coating electrodes but is not limited to it. It can also be used for coating other films such as paper, cloth, plastic film, etc. to obtain a composite material (film), thereby obtaining a composite material (film) with certain properties.

[0042] The technical solutions of the coating die head and the coating device for the electrode provided in the specific implementation manner of the present application are further described below.

[0043] like Figure 1 As shown, some embodiments of the present application provide a coating die, which includes a first die 1, a second die 2, a third die 3, a first coating gasket 4 and a second coating gasket 6, the second die 2 is arranged opposite to the first die 1, the third die 3 is arranged between the first die 1 and the second die 2, the first coating gasket 4 is sandwiched between the first die 1 and the third die 3, the first coating gasket 4 includes a first baffle 41, a second baffle 42 and a third baffle 43 arranged along a first direction X, the first die 1, the third die 3, the first baffle 41 and the third baffle 43 define a first coating port 5, the second baffle 42 It is spaced apart from the first coating port 5. In the first direction X, at least one of the first baffle 41 and the third baffle 43 is spaced apart from the second baffle 42. The second coating gasket 6 is sandwiched between the second die 2 and the third die 3. The second coating gasket 6 includes a fourth baffle 61 and a fifth baffle 62 arranged along the first direction X. The second die 2, the third die 3, the fourth baffle 61 and the fifth baffle 62 define a second coating port 7 and a channel connected to the second coating port 7. The channel includes a necking section 8 connected to the second coating port 7. The size of the necking section 8 in the first direction X gradually decreases in the direction away from the second coating port 7.

[0044] The first die head 1, the second die head 2 and the third die head 3 can all be components in the coating die head, and they are stacked and connected to form the coating die head, and can also form a channel for conveying slurry in the coating die head. Among them, the third die head 3 is arranged between the second die head 2 and the first die head 1 which are arranged opposite to each other.

[0045] The first coating gasket 4 and the second coating gasket 6 can both be components in the coating die. The first coating gasket 4 is clamped between the first die 1 and the third die 3, so that a gap connected to the channel for conveying the slurry can be formed between the first die 1 and the third die 3, and the gap can serve as a first coating port 5 to flow out the slurry; the second coating gasket 6 is clamped between the second die 2 and the third die 3, so that a gap connected to the channel for conveying the slurry can be formed between the second die 2 and the third die 3, and the gap can serve as a second coating port 7 to flow out the slurry.

[0046] Exemplarily, the coating die head can be used for double-layer coating, and the components of the slurry flowing out of the first coating port 5 and the second coating port 7 are different, which is beneficial for the pole piece to obtain better dynamic performance.

[0047] The first baffle 41, the second baffle 42 and the third baffle 43 can be different parts of the first coating gasket 4, which are used to form a notch structure in the first coating gasket 4, and together with the first die 1 and the third die 3 form the first coating port 5, so that the slurry can flow out from the first coating port 5.

[0048] By spacing the second baffle 42 and the first coating port 5 , a gap is formed between the second baffle 42 and the first coating port 5 , and the gap can serve as a channel connected to the first coating port 5 , so that the slurry delivered to the coating die head can flow to the first coating port 5 through the channel so as to flow out from the first coating port 5 .

[0049] By arranging at least one of the first baffle 41 and the third baffle 43 to be spaced apart from the second baffle 42 in the first direction X, a gap is formed between at least one of the first baffle 41 and the third baffle 43 and the second baffle 42 in the first direction X. The gap can serve as a channel connected to the first coating port 5, so that the slurry delivered to the coating die head can flow to the first coating port 5 through the channel so as to flow out from the first coating port 5.

[0050] Since the second baffle 42 is spaced apart from the first coating port 5, and at least one of the first baffle 41 and the third baffle 43 is spaced apart from the second baffle 42 in the first direction X, in the direction away from the first coating port 5, the length of the channel formed between at least one of the first baffle 41 and the third baffle 43 and the second baffle 42 is greater than the length of the channel formed between the second baffle 42 and the first coating port 5, so that the slurry flows more from the channel between the second baffle 42 and at least one of the first baffle 41 and the third baffle 43 to the first coating port 5 than the channel between the second baffle 42 and the first coating port 5, and the thickness of the slurry layer corresponding to the gap between the second baffle 42 and at least one of the first baffle 41 and the third baffle 43 is greater than the thickness of the slurry layer corresponding to the gap between the second baffle 42 and the first coating port 5.

[0051] The fourth baffle 61 and the fifth baffle 62 can be different parts of the second coating gasket 6, which are used to form a notch structure in the second coating gasket 6, and together with the second die 2 and the third die 3 form a second coating port 7, so that the slurry can flow out from the second coating port 7.

[0052] By arranging the fourth baffle 61 and the fifth baffle 62 at intervals along the first direction X, the fourth baffle 61 and the fifth baffle 62 form a gap connected to the second coating port 7, and the gap is a channel connected to the second coating port 7, so that the slurry delivered to the coating die head can flow to the second coating port 7 through the channel so as to flow out from the second coating port 7.

[0053] The constricted section 8 may be a portion of the channel connected to the second coating port 7. By configuring the dimension of the constricted section 8 in the first direction X to gradually decrease in the direction away from the second coating port 7, the dimension of the channel connected to the second coating port 7 in the first direction X gradually decreases from the second coating port 7, so that the slurry flowing out of the second coating port 7 corresponding to the edge of the constricted section 8 in the first direction X is less than that in the interior, and the slurry layer corresponding to the edge of the constricted section 8 in the first direction X is thinner than that in the interior.

[0054] Exemplarily, the second coating port 7 and the first coating port 5 are arranged opposite to each other, so that the slurry flowing out of the second coating port 7 and the slurry flowing out of the first coating port 5 are stacked on the pole piece.

[0055] Through the above structure, the thickness of different slurry layers coated by the coating die head at different positions in the first direction X varies, so that the thickness distribution of different slurry layers coated on the pole piece is more reasonable, and the components of the entire slurry layer can be changed, which is beneficial to improving the dynamic performance of the pole piece.

[0056] In some embodiments, Figure 2 As shown, the second coating gasket 6 is provided with a second notch 63 located between the fourth baffle 61 and the fifth baffle 62, the second notch 63 includes a notch area 631 and an open area 632 connected to the notch area 631, the open area 632 is connected between the notch area 631 and the second coating port 7, and the size of the open area 632 in the first direction X gradually decreases in the direction away from the second coating port 7 to form a necking section 8.

[0057] The second notch 63 may be a notch structure formed by removing material from the second coating gasket 6, which is disposed between the fourth baffle 61 and the fifth baffle 62 and connected to the edge of the second coating gasket 6. When the second coating gasket 6 is sandwiched between the second die 2 and the third die 3, the second notch 63 forms a channel connected to the second coating port 7, so that the slurry can flow to the second coating port 7 through the channel so as to flow out from the second coating port 7.

[0058] For example, the second notch 63 can be formed by removing material from the second coated gasket 6 through a stamping process, which is beneficial for improving the processing convenience of the second coated gasket 6 .

[0059] In some embodiments, the notch area 631 and the open area 632 are different areas connected to each other by the second notch 63. The open area 632 is connected between the notch area 631 and the second coating port 7, and the open area 632 and the notch area 631 are arranged in sequence along the direction away from the second coating port 7. When the second coating gasket 6 is sandwiched between the second die head 2 and the third die head 3, the open area 632 forms a necking section 8.

[0060] The size of the open area 632 in the first direction X gradually decreases in the direction away from the second coating port 7, which may mean that the size of the end of the open area 632 connected to the second coating port 7 in the first direction X is larger than the size of the end of the open area 632 connected to the notch area 631 in the first direction X, and the size of the open area 632 in the first direction X gradually decreases along the direction away from the second coating port 7, so that in the process of the slurry flowing from the channel formed by the notch area 631 through the channel formed by the open area 632 and flowing out of the second coating port 7, the thickness of the slurry layer corresponding to the channel part whose size increases in the first direction X will be smaller than the thickness of the slurry layer in other parts, so that the thickness of the slurry layer corresponding to the notch area 631 is greater than the thickness of the slurry layer corresponding to the open area 632, so that the thickness of the slurry layer is no longer consistent, thereby realizing the change of the thickness of the slurry layer in the first direction X, which is conducive to making the thickness distribution of the slurry layer more reasonable.

[0061] Exemplarily, the second coating port 7 connected to the open area 632 beyond the notch area 631 in the first direction X is opposite to the first coating port 5 connected to the gap between the first baffle 41 or the third baffle 43 and the second baffle 42, so that the slurry flowing out from the two places is stacked on the pole piece, so that the thickness of the overall slurry layer on the pole piece remains unchanged, and it is not easy to change the overall dimensional parameters of the pole piece.

[0062] In some embodiments, when viewed along the second direction Y, the second baffle 42 overlaps the notch area 631 in the first direction X, and the second direction Y is perpendicular to the first direction X.

[0063] The second direction Y is a direction perpendicular to the first direction X. Since the second baffle 42 can reduce the thickness of the corresponding slurry layer area, and the notch area 631 can increase the thickness of the corresponding slurry layer area. By setting, when observed along the second direction Y, the second baffle 42 and the notch area 631 overlap in the first direction X, so that the area of ​​the slurry layer corresponding to the notch area 631 can be laminated on the area of ​​the slurry layer corresponding to the second baffle 42, which is conducive to keeping the thickness of the entire slurry layer unchanged and not easily changing the overall size parameters of the pole piece.

[0064] In some embodiments, in the first direction X, the maximum dimension of the open area 632 extending beyond the notch area 631 is L1, and the maximum dimension of the open area 632 in the direction away from the second coating port 7 is L2, 8mm≤L1≤20mm, 15mm≤L2≤35mm.

[0065] By setting the range of the maximum dimension L1 of the open area 632 extending out of the notch area 631 in the first direction X to 8mm≤L1≤20mm, not only is the edge portion of the slurry layer formed by the slurry flowing out of the second coating port 7 provided with a sufficient thinning area so as to change the thickness of the slurry layer corresponding to the second coating port 7 in the first direction X, but also the dimension of the open area 632 extending out in the first direction X is not too large, so that the slurry can be more smoothly filled in the area where the open area 632 extends out of the notch area 631 in the first direction X, which is beneficial to reduce the possibility of coating leakage.

[0066] Exemplarily, the range of the maximum dimension L1 of the open area 632 extending out of the notch area 631 in the first direction X is set to 10 mm ≤ L1 ≤ 20 mm. The maximum dimension of the open area 632 extending out of the notch area 631 in the first direction X can be 13 mm, 15 mm or 18 mm, which not only allows the edge portion of the slurry layer formed by the slurry flowing out of the second coating port 7 to have a sufficient thinning area, but also allows the slurry to be more smoothly filled in the area where the open area 632 extends out of the notch area 631 in the first direction X.

[0067] By setting the maximum dimension L2 of the open area 632 in the direction away from the second coating port 7 to 15mm≤L2≤35mm, the flow rate of the slurry can be slowed down in the process of flowing to the necking section 8 to significantly reduce the thickness of the formed slurry layer, and the slurry can also be filled more smoothly in the area of ​​the open area 632 extending out of the notch area 631 in the first direction X, which is beneficial to reduce the possibility of missing coating.

[0068] Exemplarily, the maximum dimension L2 of the open area 632 in the direction away from the second coating port 7 is set to 20 mm ≤ L2 ≤ 35 mm. The maximum dimension L2 of the open area 632 in the direction away from the second coating port 7 is 25 mm, 28 mm or 30 mm, which not only makes it possible to significantly reduce the thickness of the slurry layer at the edge of the slurry layer formed by the slurry flowing out of the second coating port 7, but also makes it possible for the slurry to be more smoothly filled in the area of ​​the open area 632 extending out of the notch area 631 in the first direction X.

[0069] In some embodiments, the open area 632 is configured as a trapezoid.

[0070] By configuring the open area 632 into a trapezoid, the upper base of the trapezoid is connected to the notch area 631, and the lower base of the trapezoid is connected to the second coating port 7. This not only allows the flow area of ​​the slurry to be expanded when it flows from the channel formed by the notch area 631 into the channel formed by the open area 632, but also allows the open area 632 to connect the notch area 631 and the second coating port 7 well.

[0071] Exemplarily, the trapezoid can be set as an isosceles trapezoid so that the open area 632 can form a thinning area on the slurry layer on both sides of the first direction X. The trapezoid can also be set as a right-angled trapezoid so that the open area 632 forms a thinning area on the slurry layer on one side of the first direction X.

[0072] In some embodiments, Figure 3 As shown, the first coating gasket 4 is provided with a first notch 44, the first notch 44 includes a flow reduction area 441 and a flow-through area 442 connected to the flow reduction area 441 and away from the first coating port 5, the flow reduction area 441 is connected to the first coating port 5, at least one of the first baffle 41 and the third baffle 43 is spaced apart from the second baffle 42 through the flow-through area 442, and the second baffle 42 is spaced apart from the first coating port 5 through the flow reduction area 441.

[0073] The first notch 44 may be a notch structure formed by removing material from the first coating gasket 4. The first notch 44 is surrounded by the first baffle 41, the second baffle 42, and the third baffle 43 and is connected to the edge of the first coating gasket 4. When the first coating gasket 4 is sandwiched between the first die 1 and the third die 3, the first notch 44 forms a channel connected to the first coating port 5, so that the slurry can flow to the first coating port 5 through the channel so as to flow out from the first coating port 5.

[0074] Exemplarily, the first notch 44 can be formed by removing material from the first coated gasket 4 through a stamping process, which is beneficial to improving the convenience of processing the first coated gasket 4 .

[0075] The flow-through area 442 and the flow-reducing area 441 are different areas interconnected with each other in the first notch 44. The flow-reducing area 441 is connected to the first coating port 5, and the flow-through area 442 is connected to the side of the flow-reducing area 441 away from the first coating port 5, so that the flow-reducing area 441 and the flow-through area 442 are arranged in sequence in a direction away from the first coating port 5.

[0076] At least one of the first baffle 41 and the third baffle 43 is arranged with the second baffle 42 through the flow area 442, which may be that in the first direction X, the flow area 442 is provided between the first baffle 41 and the second baffle 42; or in the first direction X, the flow area 442 is provided between the third baffle 43 and the second baffle 42; or in the first direction X, the flow area 442 is provided between the first baffle 41 and the second baffle 42 and between the third baffle 43 and the second baffle 42. This enables the second baffle 42 to have the flow area 442 on at least one side of the first direction X, and the flow area 442 can allow the slurry to flow smoothly.

[0077] By disposing at least one of the first baffle 41 and the third baffle 43 to be spaced apart from the second baffle 42 through the flow-through zone 442, and the second baffle 42 to be spaced apart from the first coating port 5 through the flow-reducing zone 441, the second baffle 42 can play a certain blocking role on the flow of the slurry, and the flow-through zone 442 is connected to the edge of the second baffle 42 through the flow-reducing zone 441, so that when the slurry flows from the flow-through zone 442 to the first coating port 5, the slurry will flow into the flow-reducing zone 441, the flow area of ​​the slurry can be expanded, and the flow velocity is slowed down, so that the slurry layer corresponding to the flow-reducing zone 441 is thinner.

[0078] In some embodiments, when viewed along the second direction Y, the flow area 442 and the open area 632 are aligned in the first direction X, and the second direction Y is perpendicular to the first direction X.

[0079] The second direction Y is a direction perpendicular to the first direction X. When viewed along the second direction Y, the flow area 442 and the open area 632 are aligned in the first direction X. It can be that when viewed along the second direction Y, the flow area 442 and the open area 632 are aligned in the first direction X, so that the flow area 442 and the open area 632 correspond to each other, so that the area of ​​the slurry layer corresponding to the flow area 442 outside the second baffle 42 can be laminated on the area of ​​the slurry layer corresponding to the open area 632, which is conducive to keeping the thickness of the entire slurry layer unchanged and not easily changing the overall size parameters of the pole piece.

[0080] In some embodiments, the dimension of the flow reduction zone 441 in the direction away from the first coating port 5 is L, and L≥8 mm.

[0081] By setting the dimension L of the flow reduction zone 441 in the direction away from the first coating port 5 to L≥8mm, there is enough space between the second baffle 42 and the first coating port 5 for the slurry to flow into, so that the space between the second baffle 42 and the first coating port 5 can be smoothly filled with slurry, which is beneficial to reduce the possibility of missing coating of the slurry flowing out of the first coating port 5.

[0082] Exemplarily, the size L of the flow reduction zone 441 in the direction away from the first coating port 5 is set to be L≥10 mm. The size L of the flow reduction zone 441 in the direction away from the first coating port 5 can be 15 mm, 18 mm or 20 mm, which not only allows the second baffle 42 and the first coating port 5 to be smoothly filled with slurry, but also allows the second baffle 42 to effectively slow down the flow rate of the slurry and thin the slurry layer.

[0083] In some embodiments, two flow areas 442 are provided, and the second baffle 42 is spaced apart from the first baffle 41 and the third baffle 43 by the flow areas 442 on both sides of the first direction X, and the flow reduction area 441 is connected between the two flow areas 442 .

[0084] The second baffle 42 is spaced apart from the first baffle 41 and the third baffle 43 by the flow zone 442 on both sides of the first direction X, which may mean that the first baffle 41, the second baffle 42 and the third baffle 43 are spaced apart in sequence along the first direction X, the first baffle 41 and the second baffle 42 are spaced apart by the flow zone 442, and the second baffle 42 and the third baffle 43 are spaced apart by the flow zone 442, so that the thickness of the edge areas on both sides of the slurry layer corresponding to the first coating port 5 can be changed.

[0085] In some embodiments, the first coating gasket 4 also includes a first main body plate 45, the first baffle plate 41, the second baffle plate 42 and the third baffle plate 43 are all connected to the first main body plate 45, the thickness of the second baffle plate 42 is H1, the thickness of the first main body plate 45 is H2, 0.3H2≤H1≤0.7H2.

[0086] The first main body plate 45 can be the main structure in the first coating gasket 4. By connecting the first baffle plate 41, the second baffle plate 42 and the third baffle plate 43 to the first main body plate 45, the first baffle plate 41, the second baffle plate 42, the third baffle plate 43 and the first main body plate 45 form an integral structure with good structural strength.

[0087] By setting the proportional relationship range of the thickness H1 of the second baffle 42 and the thickness H2 of the first main plate 45 to 0.3H2≤H1≤0.7H2, the second baffle 42 can partially block the slurry from flowing into the first notch 44, thereby making it difficult for the slurry flowing out of the first coating port 5 from the flow reduction zone 441 to be interrupted, which is beneficial to reduce the possibility of coating leakage.

[0088] Exemplarily, the ratio range of the thickness H1 of the second baffle plate 42 and the thickness H2 of the first main plate 45 is set to 0.4H2≤H1≤0.6H2. The ratio of the thickness H1 of the second baffle plate 42 and the thickness H2 of the first main plate 45 can be set to 0.4H2=H1, 0.5H2=H1 or 0.6H2=H1, so that the second baffle plate 42 can partially block the slurry from flowing into the first notch 44, thereby making it difficult for the slurry flowing out of the flow reduction area 441 from the first coating port 5 to be interrupted, which is conducive to reducing the possibility of coating leakage.

[0089] In some embodiments, the third die head 3 is provided with a first channel 31 , the first channel 31 is connected to the first coating port 5 , and the surface of the second baffle plate 42 facing the first die head 1 is flush with the surface of the first main body plate 45 facing the first die head 1 .

[0090] The first channel 31 may be a channel structure for conveying slurry provided in the third die head 3 , which is connected with the first notch 44 of the first coating gasket to achieve communication with the first coating port 5 , so that the slurry conveyed by the third die head 3 through the first channel 31 can flow out from the first coating port 5 .

[0091] By making the surface of the second baffle plate 42 facing the first die head 1 flush with the surface of the first main body plate 45 facing the first die head 1, a gap is provided between the surface of the second baffle plate 42 facing the third die head 3 and the third die head 3, so that the slurry flowing into the first channel 31 can flow into the flow reduction zone 441 through the gap, thereby making it difficult for the slurry flowing out of the first coating port 5 from the flow reduction zone 441 to be interrupted, which helps to reduce the possibility of coating leakage.

[0092] Exemplarily, a first connecting hole 451 is provided on the first main body plate 45, and the first coated gasket 4 clamped between the first die 1 and the third die 3 is connected to the first die 1 and the third die 3 by a first connecting member passing through the first connecting hole 451, so that the first coated gasket 4 can be well positioned between the first die 1 and the third die 3.

[0093] In some embodiments, the second coating pad 6 also includes a second main body plate 64, and the fourth baffle plate 61 and the fifth baffle plate 62 are both connected to the first main body plate 45, so that the fourth baffle plate 61, the fifth baffle plate 62 and the second main body plate 64 form an integral structure with good structural strength.

[0094] Exemplarily, a second connecting hole 641 is provided on the second main body plate 64, and the second coating gasket 6 clamped between the second die 2 and the third die 3 is connected to the second die 2 and the third die 3 by a second connecting member passing through the second connecting hole 641, so that the second coating gasket 6 can be well positioned between the second die 2 and the third die 3.

[0095] In some embodiments, the second die head 2 is provided with a second channel 21 , and the second channel 21 is connected to the second coating port 7 through the necking section 8 .

[0096] The second channel 21 can be a channel structure for conveying slurry set in the second die head 2, which is connected with the second coating port 7 through the necking section 8, so that the slurry conveyed by the second die head 2 through the second channel 21 can flow out from the first coating port 5 through the necking section 8 (the second notch 63 of the second coating gasket 6).

[0097] In some embodiments, the second baffle 42 is configured in a rectangular shape.

[0098] By configuring the second baffle 42 to be rectangular, the second baffle 42 has a good blocking effect on the slurry flowing out of the first channel 31 , which is beneficial to improving the thinning effect of the second baffle 42 on the slurry layer.

[0099] Exemplarily, the second baffle 42 may also be configured as other shapes such as a circle or a triangle, so that the second baffle 42 can play a good blocking role on the flow of the slurry.

[0100] Through the above structure, since the open area 632 of the second coating gasket 6 in the coating die head can form a constriction section 8, the corresponding slurry layer can be thinned at a distance of 0 to 15 mm from the edge on both sides of the first direction X, and the thickness of the edge areas on both sides of the first direction X can be 20% of the thickness of the middle area, so that the thickness of the slurry layer corresponding to the second coating gasket 6 can be significantly changed. At the same time, due to the setting of the second baffle 42 of the first coating gasket 4 of the coating die head, the thickness of the slurry layer corresponding to the flow area 442 of the second baffle 42 on both sides of the first direction X can be increased, so that the thickness of the entire slurry layer can be maintained unchanged. Figure 4 Schematic diagram of the thickness distribution of the slurry layer corresponding to the first coating gasket 4 and the second coating gasket 6.

[0101] Some embodiments of the present application also provide a coating device for a pole piece, the coating device comprising a coating die head provided by the aforementioned technical solution, the coating die head being used to coat slurry onto the surface of the pole piece.

[0102] Since the coating device of the pole piece includes the coating die head provided by the above technical solution, the coating device of the pole piece can make the thickness distribution of different slurry layers coated on the pole piece more reasonable, which is beneficial to improving the dynamic performance of the pole piece.

[0103] Some embodiments of the present application provide a coating die, which includes a first die 1, a second die 2, a third die 3, a first coating gasket 4 and a second coating gasket 6, wherein the third die 3 is disposed between the first die 1 and the second die 2, the first coating gasket 4 is sandwiched between the first die 1 and the third die 3, and the second coating gasket 6 is sandwiched between the second die 2 and the third die 3. The second coating gasket 6 is provided with a second notch 63 surrounded by a second main body plate 64, a fourth baffle 61 and a fifth baffle 62, the second notch 63 includes a notch area 631 and an open area 632 that are interconnected, and the size of the open area 632 in the first direction X gradually decreases in the direction away from the second coating port 7 to form a necking section 8. The first coating gasket 4 is provided with a first gap 44 surrounded by a first main plate 45, a first baffle 41, a second baffle 42 and a third baffle 43. The first gap 44 includes a flow reduction zone 441 and a flow excess zone 442. The flow reduction zone 441 is located between the second baffle 42 and the first coating port 5. The first baffle 41 and the second baffle 42 are spaced apart by the flow excess zone 442. The second baffle 42 and the third baffle 43 are spaced apart by the flow excess zone 442. Since the second baffle 42 is spaced apart from the first coating port 5, at least one of the first baffle 41 and the third baffle 43 is spaced apart from the second baffle 42 in the first direction X, more slurry flows to the first coating port 5 from the gap between the second baffle 42 and at least one of the first baffle 41 and the third baffle 43 than from the gap between the second baffle 42 and the first coating port 5, so that the slurry layer of the pole piece corresponding to the gap between the second baffle 42 and at least one of the first baffle 41 and the third baffle 43 in the first direction X is thicker; since the size of the constricted section 8 of the channel in the first direction X gradually decreases in the direction away from the second coating port 7, the edge of the slurry layer corresponding to the constricted section 8 in the first direction X is thinner, so that the thickness of different slurry layers at different positions in the first direction X is variable, so that the thickness distribution of different slurry layers applied on the pole piece is more reasonable, and the change of components at various locations of the entire slurry layer can be achieved, which is beneficial to improving the dynamic performance of the pole piece.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A coating die head, characterized in that: include: The first die head, A second die head, arranged opposite to the first die head; A third die head, disposed between the first die head and the second die head; A first coating gasket is sandwiched between the first die head and the third die head, the first coating gasket comprises a first baffle, a second baffle and a third baffle arranged along a first direction, the first die head, the third die head, the first baffle and the third baffle define a first coating port, the second baffle is spaced apart from the first coating port, and in the first direction, at least one of the first baffle and the third baffle is spaced apart from the second baffle; A second coating gasket is sandwiched between the second die head and the third die head, and the second coating gasket includes a fourth baffle and a fifth baffle arranged along the first direction. The second die head, the third die head, the fourth baffle and the fifth baffle define a second coating port and a channel connected to the second coating port, and the channel includes a necking section connected to the second coating port, and the size of the necking section in the first direction gradually decreases in the direction away from the second coating port.

2. The coating die head according to claim 1, characterized in that: The second coating gasket is provided with a second notch located between the fourth baffle and the fifth baffle, the second notch includes a notch area and an open area connected to the notch area, the open area is connected between the notch area and the second coating port, and the size of the open area in the first direction gradually decreases along the direction away from the second coating port to form the necking section.

3. The coating die head according to claim 2, characterized in that: When viewed along a second direction, the second baffle overlaps with the notch area in the first direction, and the second direction is perpendicular to the first direction.

4. The coating die head according to claim 2, characterized in that: In the first direction, the maximum dimension of the open area extending from the notch area is L1, and the maximum dimension of the open area in the direction away from the second coating port is L2, 8mm≤L1≤20mm, 15mm≤L2≤35mm.

5. The coating die head according to claim 2, characterized in that: The open area is configured in a trapezoidal shape.

6. The coating die head according to claim 2, characterized in that: The first coating gasket is provided with a first notch, the first notch includes a flow reduction zone and a flow-through zone connected to the flow reduction zone on a side away from the first coating port, the flow reduction zone is connected to the first coating port, at least one of the first baffle and the third baffle is spaced apart from the second baffle through the flow-through zone, and the second baffle is spaced apart from the first coating port through the flow reduction zone.

7. The coating die head according to claim 6, characterized in that: When viewed along a second direction, the flow-through area and the open area are aligned in the first direction, and the second direction is perpendicular to the first direction.

8. The coating die head according to claim 6, characterized in that: The dimension of the flow reduction zone in the direction away from the first coating port is L, and L is ≥ 8 mm.

9. The coating die head according to claim 6, characterized in that: There are two flow areas, the second baffle is arranged at both sides of the first direction through the flow areas and is spaced from the first baffle and the third baffle respectively, and the flow reduction area is connected between the two flow areas.

10. The coating die head according to claim 2, characterized in that: The first coating gasket also includes a first main body plate, the first baffle plate, the second baffle plate and the third baffle plate are all connected to the first main body plate, the thickness of the second baffle plate is H1, the thickness of the first main body plate is H2, 0.3H2≤H1≤0.7H2.

11. The coating die head according to claim 10, characterized in that: The third die head is provided with a first channel, the first channel is connected to the first coating port, and the surface of the second baffle plate facing the first die head is flush with the surface of the first main body plate facing the first die head.

12. The coating die head according to claim 1, characterized in that: The second die head is provided with a second channel, and the second channel is connected to the second coating port through the necking section.

13. The coating die head according to claim 1, characterized in that: The second baffle is configured in a rectangular shape.

14. A coating device for a pole piece, characterized in that: It comprises a coating die as described in any one of claims 1 to 13, wherein the coating die is used to coat slurry onto the surface of a pole piece.

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