Pole piece processing device

Abstract

The utility model discloses a pole piece processing device. The pole piece processing device comprises a transmission assembly, two structural parts and an adsorption assembly. At least one structural member is a functional structural member, and the functional structural member comprises a main body part and a top pressing part; the top pressing part comprises a first convex part and a second convex part; the height of the first convex part protruding out of the surface of the main body part is smaller than that of the second convex part protruding out of the surface of the main body part; the adsorption assembly comprises a bonding piece, and the functional structural piece is used for being matched with another structural piece so that the bonding section of the bonding piece can abut against the pole piece; and the functional structural member is configured to press the bonding section towards the pole piece through the pressing part, so that the part, pressed by the pressing part, of the bonding section is bonded with at least part of the active substance at the corresponding position on the pole piece, and the bonded active substance is taken away from the pole piece. According to the pole piece processing device, the active substances on the pole piece can be removed, the active substances are not easy to remove too much, the problem of local super-thickness is solved, and the accurate control on the active substance removal area is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage, and particularly relates to a pole piece processing device. BACKGROUND

[0002] In order to reduce lithium precipitation of an anode pole piece, the size of the anode pole piece is designed to be larger than that of a cathode pole piece, and the size of the anode pole piece that is more than that of the cathode pole piece is referred to as an anode overhang. This design causes a part of a cathode tab to overlap the position of the anode overhang. The end surface of the cut tab has burrs, and the cathode tab may be pierced to contact the overhang short circuit. In order to prevent the short circuit between the position of the anode pole piece overhang and the cathode tab, an insulating layer is usually coated on the edge of the cathode active material area in the battery manufacturing process. When the insulating layer is coated, the insulating layer inevitably overlaps the cathode edge active material to cause the problem of pole piece over-thickness, which may cause the edge of the pole piece to crack during cold pressing, and the local over-thickness of the finished battery, thereby affecting the energy density of the battery.

[0003] In the related art, the thickness of the active material is thinned by removing a certain amount of edge active material, thereby improving the problem. However, the removal area of the active material is difficult to control in this processing method, and the removal area usually inevitably extends several millimeters from the edge to the inside, causing the active material in the area to be less than the actual design value. CONTENT OF THE UTILITY MODEL

[0004] Therefore, it is necessary to provide a pole piece processing device that can remove the active material on the pole piece and make the active material not easy to be removed too much, improve the problem of local over-thickness, and improve the accurate control of the removal area of the active material.

[0005] The embodiment of the first aspect of the present application provides an electrode sheet processing device, which comprises a conveying assembly, two structural members and an adsorption assembly. The conveying assembly is configured to move the electrode sheet along a preset direction; at least one of the structural members is a functional structural member, one of the functional structural members is configured to be movably arranged on a first side of the electrode sheet provided with active material, and the other structural member is configured to be arranged on a second side of the electrode sheet opposite to the first side; the functional structural member comprises a main body part and a pressing part protruding from the surface of the main body part; the pressing part comprises a first protruding part and a second protruding part arranged on the first protruding part; the height of the first protruding part protruding from the surface of the main body part is a first height, the height of the second protruding part protruding from the surface of the main body part is a second height, and the first height is smaller than the second height; the adsorption assembly comprises an adhesive member, at least part of the adhesive member is located between the functional structural member and the electrode sheet, and the adhesive member comprises an adhesive segment; the functional structural member is used to cooperate with the other structural member to press the adhesive segment on the electrode sheet; and the functional structural member is configured to press the adhesive segment on the electrode sheet by the pressing part, so that at least part of the active material at the position corresponding to the pressing of the adhesive segment by the pressing part is adhered to the electrode sheet, and the adhered active material is taken away from the current collector of the electrode sheet; and the pressure applied by the first protruding part on the adhesive segment is smaller than the pressure applied by the second protruding part on the adhesive segment.

[0006] The electrode sheet is moved along a preset direction under the action of the conveying assembly, when the electrode sheet moves to contact the functional structural member, the functional structural member can press the adhesive member on the electrode sheet by the pressing part, and the other structural member can provide support and limit for the electrode sheet. When the pressing part contacts the active material, the second protruding part applies greater pressure on the adhesive segment, so that the adhesive segment can adhere the active material at the position corresponding to the second protruding part, and it is easy to form a hollow foil area on the electrode sheet. Compared with the first protruding part, the active material adhered on the adhesive segment at the position corresponding to the first protruding part is less, and the part of the functional structural member surface without the pressing part is not easy to take the active material away, so that a step-shaped active material removal area can be formed on the electrode sheet. Moreover, the active material is adhered and taken away by the pressing of the first protruding part and the second protruding part on the adhesive layer, so that the removal position and the removal amount of the active material are easily controlled, the active material is not easy to be removed too much, the problem of local over-thickness of the electrode sheet is improved, and the accurate control of the active material removal area is improved.

[0007] In at least one embodiment, the functional structural member is rotatably arranged, the main body part is a first core part, and the pressing part protrudes from the outer circumferential surface of the first core part; the first height is the height of the first protruding part protruding from the outer circumferential surface of the first core part along the radial direction of the first core part, and the second height is the height of the second protruding part protruding from the outer circumferential surface of the first core part along the radial direction of the first core part.

[0008] The top pressing part is arranged on the first core part, so that when the first core part rotates, the top pressing part rotates with the first core part, and when the top pressing part presses the bonding segment to the pole piece, a gap exists between the surface of the first core part where the top pressing part is not arranged and the pole piece, thereby facilitating that the part of the bonding segment not corresponding to the top pressing part does not easily carry the active material away from the current collector, and facilitating the formation of a stepped active material on the pole piece.

[0009] In at least one embodiment, the two structural members are respectively a first structural member and a second structural member, the first structural member is a functional structural member; the second structural member includes a second core part, and the second core part is rotatably arranged; when the top pressing part presses the bonding segment to the pole piece, a part of the outer circumferential surface of the second core part is opposite to the first protrusion along the thickness direction of the pole piece, and the top pressing part and the part of the outer circumferential surface of the second core part clamp the pole piece and the bonding segment.

[0010] The outer circumferential surface of the second core part can clamp the pole piece and the bonding segment together with the top pressing part, thereby facilitating that the bonding segment can remove the active material of the corresponding part through bonding.

[0011] In at least one embodiment, the two structural members are both functional structural members, and the two structural members are configured to be arranged opposite to each other along the thickness direction of the pole piece; the two structural members are respectively a first structural member and a second structural member, when the top pressing part of the first structural member presses the bonding segment to the pole piece, the first protrusion of the second structural member is opposite to the first protrusion of the first structural member along the thickness direction of the pole piece, the second protrusion of the second structural member is opposite to the second protrusion of the first structural member along the thickness direction of the pole piece, and the top pressing part of the first structural member and the top pressing part of the second structural member clamp the pole piece and the bonding segment.

[0012] The top pressing parts of the two structural members can cooperate with each other to press the pole piece and the bonding segment, so that the bonding segment exerts greater pressure on the active material of the pole piece, thereby more facilitating that the bonding segment bonds the active material, and improving the removal effect of the active material.

[0013] In at least one embodiment, the bonding member includes a first bonding member and a second bonding member, a part of the first bonding member is arranged between the pole piece and the first structural member, and a part of the second bonding member is arranged between the pole piece and the second structural member.

[0014] The first structural member and the second structural member can cooperate with each other, so that the top pressing part of the first structural member presses the part of the first bonding member on the active material of one surface of the current collector, the top pressing part of the second structural member presses the part of the second bonding member on the active material of the other surface of the current collector, and when the bonding segments of the first bonding member and the second bonding member are away from the pole piece, the active material on the opposite surfaces of the current collector can be carried away at the same time, thereby realizing the removal of the active material on both surfaces of the pole piece and providing the processing efficiency of the pole piece.

[0015] In at least one embodiment, the plurality of pressing portions are arranged in a plurality of rows along the axial direction of the first core portion, and the plurality of pressing portions in each row are arranged in a row along the circumferential direction of the first core portion.

[0016] When the pole piece moves in the preset direction, the plurality of pressing portions arranged in the plurality of rows can be sequentially contacted with the adhesive member as the functional structural member rotates, so that the adhesive member can carry the active material corresponding to the portion pressed by the pressing portion away from the current collector, thereby forming a plurality of spaced active material removal areas on the surface of the pole piece, so as to facilitate subsequent cutting of the entire pole piece to form a plurality of pole pieces with active material removal areas; the plurality of pressing portions arranged in the plurality of rows can form a plurality of continuous step-shaped active material removal areas on the pole piece in the moving direction under the action of the adhesive member and the first pressing portion, so as to facilitate subsequent cutting of the entire pole piece to form a plurality of pole pieces with active material removal areas.

[0017] In at least one embodiment, the two structural members are a first structural member and a second structural member, the first structural member is a functional structural member, the first structural member is configured to move towards or away from the second structural member, the first structural member presses the adhesive segment towards the pole piece by moving towards the second structural member, and the adhesive segment adheres to the active material; the first structural member moves away from the second structural member, and the adhesive segment carries the adhered active material away from the current collector.

[0018] The functional structural member is moved towards the second structural member, so that the pressing portion of the functional structural member presses the adhesive segment to the pole piece, so that the active material on the pole piece corresponding to the adhesive segment can be adhered to the adhesive segment; and then the functional structural member is moved away from the second structural member, so that the active material on the pole piece corresponding to the adhesive segment can be carried away from the current collector.

[0019] In at least one embodiment, the two structural members are both functional structural members; the two structural members are configured to be arranged opposite to each other along the thickness direction of the pole piece; the second structural member is configured to move towards or away from the first structural member; when the pressing portion of the first structural member presses the adhesive segment towards the pole piece, the first protrusion of the second structural member is opposite to the first protrusion of the first structural member along the thickness direction of the pole piece, the second protrusion of the second structural member is opposite to the second protrusion of the first structural member along the thickness direction of the pole piece, and the pressing portion of the first structural member and the pressing portion of the second structural member clamp the pole piece and the adhesive segment.

[0020] The first structure and the second structure can be close to each other, so that the first protruding part of the first structure and the first protruding part of the second structure clamp the pole piece and the bonding segment, and the bonding segment bonds the active substance on the pole piece; and so that the second protruding part of the first structure and the second protruding part of the second structure clamp the pole piece and the bonding segment, and the bonding segment bonds the active substance on the pole piece. Through the joint action of the top pressing parts of the first structure and the second structure, the bonding segment is more convenient to bond and remove the active substance.

[0021] In at least one embodiment, the second side has an active substance, and the bonding member includes a first bonding member and a second bonding member, a part of the first bonding member is arranged between the pole piece and the first structure, and a part of the second bonding member is arranged between the pole piece and the second structure.

[0022] When the first structure and the second structure are close to each other, the first bonding member is pressed by the top pressing part of the first structure to press the bonding segment of the first bonding member on the active substance on one side of the pole piece, and at the same time, the second bonding member is pressed by the top pressing part of the second structure to press the bonding segment of the second bonding member on the active substance on the other side of the pole piece; when the first structure and the second structure are away from each other, the first bonding member and the second bonding member remove the active substances on both sides of the pole piece, so as to realize the simultaneous removal of the active substances on both sides of the pole piece.

[0023] In at least one embodiment, the first height is D1, the second height is D2, and the following conditions are met: 20um≥D2-D1≥5um, and D2≥0.2mm.

[0024] 20um≥D2-D1≥5um can avoid that the step height difference formed by the removal position of the active substance is too large, reduce the case that the pole piece corresponding to the first protruding part is completely not stripped of the active substance, and also reduce the case that the pole piece corresponding to the first protruding part is completely stripped of the active substance due to the too small step height difference. D2≥0.2mm can reduce the case that the bonding member bonds the active substance of the pole piece at a position corresponding to the non-top pressing part.

[0025] In at least one embodiment, the bonding member is a single-sided tape, and one side of the single-sided tape facing the pole piece has adhesion.

[0026] The side of the bonding member with adhesion can bond the active substance; when the structure member presses the bonding member, the side of the bonding member without adhesion is in contact with the structure member, so that after the bonding member bonds the active substance, the side without adhesion is separated from the structure member, reducing the case that the bonding member is not easy to separate from the structure member and affects subsequent processing.

[0027] In at least one embodiment, the bonding member includes hot melt adhesive; and the pole piece processing device further includes a heating member arranged on the functional structure member, and used for heating the functional structure member.

[0028] The hot melt adhesive has no or less adhesion when not activated, so that the bonding member is not easy to be bonded with other structures before contacting with the functional structural member; when the bonding member contacts with the functional structural member, the heating member can heat the hot melt adhesive, so as to activate the adhesion of the hot melt adhesive, and facilitate the bonding segment to bond the active substance when the functional structural member presses the bonding segment.

[0029] In at least one embodiment, a projection of the first convex portion on the surface of the main body portion is a first projection, and a projection of the second convex portion on the surface of the main body portion is a second projection; in the first direction, the first projection protrudes on both sides of the first direction relative to the second projection.

[0030] The first convex portion protrudes on both sides of the first direction relative to the second convex portion, which makes the bonding segment bond two step-shaped structures of removing active substances in the first direction of the pole piece when the pressing portion presses the bonding segment, so as to facilitate subsequent cutting of two pole pieces each having a step-shaped structure along the first direction of the entire pole piece, and improve the removal efficiency of the active substance on the pole piece. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a schematic view of a pole piece processing device in an embodiment of the present application.

[0032] Figure 2 is a schematic view of a first structural member in an embodiment of the present application.

[0033] Figure 3 is a partial schematic view of a bonding member in an embodiment of the present application.

[0034] Figure 4 is a partial schematic view of a pole piece in an embodiment of the present application.

[0035] Figure 5 is a schematic view of a pole piece processing device in an embodiment of the present application.

[0036] Figure 6 is a schematic view of a functional structural member in an embodiment of the present application.

[0037] Figure 7 is Figure 2 is an enlarged view of the middle VII part.

[0038] Figure 8 is a schematic view of a functional structural member in an embodiment of the present application.

[0039] Figure 9 is a schematic view of a first structural member in an embodiment of the present application.

[0040] Figure 10 is a partial view of a display structure and a bonding member in an embodiment of the present application.

[0041] Figure 11 is a schematic view of a pole piece processing device in an embodiment of the present application.

[0042] Figure 12 is a partial sectional view of an adhesive in an embodiment of the present application.

[0043] Figure 13 is a schematic view of a pole piece processing device in an embodiment of the present application.

[0044] Figure 14 is a schematic view of a pole piece processing device in an embodiment of the present application.

[0045] Figure 15 is a partial sectional view of a pole piece in an embodiment of the present application.

[0046] Main element symbol explanation

[0047] 100, pole piece processing device; 10, transmission assembly; 11, conveying roller; 20, structural member; 20a, functional structural member; 201, main body portion; 201a, first core portion; 202, top pressing portion; 2021, first protruding portion; 2022, second protruding portion; 2023, third protruding portion; 21, first structural member; 22, second structural member; 221, second core portion; 30, adsorption assembly; 31, adhesive; 31a, first adhesive; 31b, second adhesive; 311, adhesive section; 312, base film; 313, adhesive layer; 32, first roller body; 33, second roller body; 200, pole piece; 2001, current collector; 2001a, empty foil area; 2002, active material; 2003, first side; 2004, second side; 2005, groove; P, preset direction; X, first direction; Z, second direction; L, axial direction; R, circumferential direction.

[0048] The following detailed description will further describe the present application with reference to the above drawings. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of the embodiments of the present application.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0051] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0052] In order to reduce the lithium precipitation of the anode tab, the size of the anode tab is designed to be larger than that of the cathode tab, and the size of the anode tab that is more than that of the cathode tab is called the overhanging edge. This design will cause a part of the cathode tab to overlap with the position of the overhanging edge. The end face of the cut tab has burrs, and the cathode tab may be pierced and short-circuited. In order to prevent the short circuit between the overhanging edge of the anode tab and the cathode tab, an insulating layer is usually coated on the edge of the cathode active material area during the battery manufacturing process. When the insulating layer is coated, the active material in the overlapping area between the insulating layer and the cathode edge will inevitably be removed, which may cause the edge of the tab to crack during cold pressing, and the local thickness of the finished battery to be too thick, thereby affecting the energy density of the battery.

[0053] In the related art, the thickness of the active material is thinned by removing a certain amount of the edge active material, thereby improving the problem. However, the removal area of the active material is difficult to control in this processing method, and it usually inevitably extends several millimeters inward from the edge, causing the amount of active material in the area to be less than the actual design value.

[0054] Embodiments of the present application provide a tab processing device, comprising a transmission assembly, two structural members and an adsorption assembly. The transmission assembly is configured to move the tab along a predetermined direction; at least one of the structural members is a functional structural member, one of the functional structural members is configured to be movably arranged on a first side of the tab provided with active material, and the other structural member is configured to be arranged on a second side of the tab opposite to the first side. The functional structural member comprises a main body part and a pressing part protruding from the surface of the main body part; the pressing part comprises a first protruding part and a second protruding part, and the second protruding part is arranged on the first protruding part; the height of the first protruding part protruding from the surface of the main body part is a first height, the height of the second protruding part protruding from the surface of the main body part is a second height, and the first height is less than the second height; the adsorption assembly comprises an adhesive member, at least part of the adhesive member is located between the functional structural member and the tab, and the adhesive member comprises an adhesive segment; the functional structural member is configured to cooperate with the other structural member to press the adhesive segment on the tab; and the functional structural member is configured to press the adhesive segment on the tab by the pressing part, so that at least part of the active material at the position corresponding to the adhesive segment on the tab is adhered, and the adhered active material is taken away from the current collector of the tab; the pressure applied by the first protruding part on the adhesive segment is less than the pressure applied by the second protruding part on the adhesive segment.

[0055] The pole piece is moved along a preset direction by the transmission assembly. When the pole piece contacts the functional structural member, the functional structural member can press the bonding member onto the pole piece by the pressing part, and the other structural member can provide support and limit for the pole piece. When the pressing part contacts the active substance, the second protruding part has a greater pressure on the bonding segment, so that the bonding segment can bond the active substance at the position corresponding to the second protruding part, and it is easy to form an empty foil area on the pole piece. Compared with the first protruding part, the active substance bonded on the bonding segment at the position corresponding to the first protruding part is less, and the part of the surface of the functional structural member without the pressing part is not easy to take the active substance away, so that a step-shaped active substance removal area can be formed on the pole piece. Moreover, the active substance is bonded away by the pressing of the first protruding part and the second protruding part on the bonding segment, so that the removal position and the removal amount of the active substance are easily controlled, the active substance is not easy to be removed too much, the problem of local over-thickness of the pole piece is improved, and the accurate control of the active substance removal area is improved.

[0056] The embodiments of the present application are further described below with reference to the drawings.

[0057] As shown in Figure 1 , the embodiments of the present application provide a pole piece processing device 100, which comprises a transmission assembly 10, two structural members 20 and an adsorption assembly 30, and the pole piece processing device 100 can remove the active substance 2002 on the pole piece 200.

[0058] In some embodiments, the pole piece 200 comprises a current collector 2001 and an active substance 2002. Along the thickness direction of the current collector 2001, the current collector 2001 has two opposite surfaces; the active substance 2002 is arranged on at least one surface of the current collector 2001; along the thickness direction of the pole piece 200, the pole piece 200 has a first side 2003 and a second side 2004 facing away from each other, and the first side 2003 has the active substance 2002. It can be understood that when the active substance 2002 is arranged on both surfaces of the current collector 2001, the first side 2003 and the second side 2004 both have the active substance 2002.

[0059] Please refer to Figures 1 to 3 , in some embodiments, the transmission assembly 10 is configured to move the pole piece 200 along a preset direction P. In Figure 1 , the moving direction of the pole piece 200 is from left to right, that is, the length direction of the pole piece 200.

[0060] At least one structural member 20 is a functional structural member 20a, one of which is movably arranged on the first side 2003 of the pole piece 200 provided with the active substance 2002, and the other structural member 20 is arranged on the second side 2004.

[0061] The functional structural component 20a includes a main body 201 and a pressing part 202, with the pressing part 202 protruding from the surface of the main body 201. The pressing part 202 includes a first protrusion 2021 and a second protrusion 2022, with the second protrusion 2022 disposed on the first protrusion 2021. The first protrusion 2021 protrudes from the surface of the main body 201 by a first height, and the second protrusion 2022 protrudes from the surface of the main body 201 by a second height, wherein the first height is less than the second height. Figure 4 This is a cross-sectional view along the width of electrode 200, used to show the shape of one side of electrode 200 after the active material 2002 has been removed.

[0062] The adsorption assembly 30 includes an adhesive member 31, at least a portion of which is located between the functional structural member 20a and the electrode 200. The adhesive member 31 includes an adhesive segment 311.

[0063] The functional structural member 20a is used to cooperate with another structural member 20 to press the adhesive segment 311 against the electrode 200; and the functional structural member 20a is configured to press the adhesive segment 311 against the electrode 200 through the pressing portion 202, so that the portion of the adhesive segment 311 pressed by the pressing portion 202 adheres to at least a portion of the active material 2002 at the corresponding position on the electrode 200, and removes the adhered active material 2002 away from the current collector 2001, wherein the pressure applied by the first protrusion 2021 to the adhesive segment 311 is less than the pressure applied by the second protrusion 2022 to the adhesive segment 311.

[0064] Please see Figure 4 The bonding section 311, under the pressure of the first protrusion 2021, partially peels off the active material 2002 at the corresponding position of the electrode 200, and under the pressure of the second protrusion 2022, completely peels off the active material 2002 at the corresponding position of the electrode 200, resulting in the thickness of the electrode 200 at the partially peeled-off position being greater than the thickness at the completely peeled-off position. Understandably, in actual production, when the surface of the current collector 2001 is exposed and a small amount of active material 2002 powder remains on the surface of the current collector 2001, this also constitutes a case of complete peeling off of the active material 2002. For example, when photographing the residual active material 2002 under a microscope, if the coverage area of ​​the active material 2002 on the current collector 2001 is ≤1%, this is considered a case of complete peeling off of the active material 2002.

[0065] The pole piece 200 is moved along the preset direction P by the transmission assembly 10. When the pole piece 200 is in contact with the functional structure 20a, the functional structure 20a can press the adhesive member 31 upward to the pole piece 200 through the pressing portion 202, and the other structure 20 can provide support and limit for the pole piece 200. When the pressing portion 202 is in contact with the active substance 2002, the second protrusion 2022 has a greater pressure on the adhesive segment 311, so that the adhesive segment 311 can adhere the active substance 2002 at the position corresponding to the second protrusion 2022, and easily form the empty foil area 2001a on the pole piece 200. Compared with the first protrusion 2021, the active substance 2002 adhered on the adhesive segment 311 at the position corresponding to the first protrusion 2021 is less, and the adhesive segment 311 corresponding to the part of the surface of the functional structure 20a where the pressing portion 202 is not arranged cannot easily take the active substance 2002 away, so that a step-shaped active substance 2002 removal area can be formed on the pole piece 200. Moreover, the active substance 2002 is adhered and taken away by the pressing of the first protrusion 2021 and the second protrusion 2022 on the adhesive segment 311, so that the removal position and the removal amount of the active substance 2002 can be easily controlled, the active substance 2002 is not easily removed too much, the problem of local over-thickness of the pole piece 200 is improved, and the accurate control of the removal area of the active substance 2002 is improved.

[0066] It can be understood that the complete stripping area of the active substance 2002 is used to form the empty foil area 2001a of the pole piece 200, and the empty foil area 2001a can be used to form a tab or for welding a tab.

[0067] Please refer to Figure 1 In some embodiments, the transmission assembly 10 includes a plurality of conveying rollers 11, the conveying rollers 11 are rotationally arranged and used to connect and convey the pole piece 200, so that the pole piece 200 moves along the preset direction P.

[0068] Please refer to Figure 1 In some embodiments, the adsorption assembly 30 includes a first roller body 32, the first roller body 32 is rotationally arranged and used to wind the adhesive member 31, so as to output the adhesive member 31.

[0069] Please refer to Figure 1 In some embodiments, the adsorption assembly 30 includes a second roller body 33, the second roller body 33 is rotationally arranged and used to wind the part of the adhesive member 31 that has adhered the active substance 2002.

[0070] Please refer to Figure 1 In some embodiments, the adhesive member 31 is moved from the first roller body 32 to the second roller body 33 by the synchronous rotation of the first roller body 32 and the second roller body 33.

[0071] Please refer to Figure 1 andFigure 2 In some embodiments, the functional structural member 20a is rotatably arranged, the main body 201 is a first core 201a, and the top pressing portion 202 is protruded from the outer circumferential surface of the first core 201a. The first height is the height of the first protrusion 2021 protruding from the outer circumferential surface of the first core 201a in the radial direction of the first core 201a, and the second height is the height of the second protrusion 2022 protruding from the outer circumferential surface of the first core 201a in the radial direction of the first core 201a.

[0072] The top pressing portion 202 is protruded from the first core 201a, so that when the first core 201a rotates, the top pressing portion 202 rotates with it, and when the top pressing portion 202 presses the bonding section 311 to the pole piece 200, there is a gap between the surface of the first core 201a where the top pressing portion 202 is not arranged and the pole piece 200, thereby facilitating that the part of the bonding section 311 not corresponding to the top pressing portion 202 does not easily carry the active material 2002 away from the current collector 2001, and facilitating the formation of a stepped active material 2002 on the pole piece 200.

[0073] Referring to Figure 1 With Figure 2 In some embodiments, the two structural members 20 are respectively a first structural member 21 and a second structural member 22, the first structural member 21 is a functional structural member 20a, and the second structural member 22 is a non-functional structural member 20a. The second structural member 22 comprises a second core 221, which is rotatably arranged. When the top pressing portion 202 presses the bonding section 311 to the pole piece 200, part of the outer circumferential surface of the second core 221 is opposite to the first protrusion 2021 in the thickness direction of the pole piece 200, and the top pressing portion 202 and the part of the outer circumferential surface of the second core 221 clamp the pole piece 200 and the bonding section 311.

[0074] The outer circumferential surface of the second core 221 can cooperate with the top pressing portion 202 to clamp the pole piece 200 and the bonding section 311, which facilitates the full contact of the bonding section 311 with the pole piece 200, so that the bonding section 311 can remove the corresponding part of the active material 2002 by bonding.

[0075] Referring to Figure 5 In some embodiments, the two structural members 20 are both functional structural members 20a, and the two structural members 20 are arranged opposite to each other in the thickness direction of the pole piece 200.

[0076] The two structural members 20 are respectively a first structural member 21 and a second structural member 22. When the pressing portion 202 of the first structural member 21 presses the adhesive section 311 towards the pole piece 200, the first protrusion 2021 of the second structural member 22 is opposite to the first protrusion 2021 of the first structural member 21 along the thickness direction of the pole piece 200, the second protrusion 2022 of the second structural member 22 is opposite to the second protrusion 2022 of the first structural member 21 along the thickness direction of the pole piece 200, and the pressing portion 202 of the first structural member 21 and the pressing portion 202 of the second structural member 22 clamp the pole piece 200 and the adhesive section 311.

[0077] The pressing portions 202 of the two structural members 20 can cooperate with each other to press the pole piece 200 and the adhesive section 311, so that the adhesive section 311 exerts greater pressure on the active substance 2002 of the pole piece 200, thereby facilitating the adhesion of the adhesive section 311 to the active substance 2002 and improving the removal effect of the active substance 2002.

[0078] Please refer to Figure 2 In some embodiments, the pressing portion 202 is provided with a plurality of pressing portions 202, which are arranged at intervals along the axial direction L of the first core portion 201a.

[0079] When the pole piece 200 moves along the preset direction P, the plurality of pressing portions 202 arranged at intervals can be in contact with the adhesive section 311 in turn as the functional structural member 20a rotates, so that the adhesive section 311 removes the active substance 2002 corresponding to the portion pressed by the pressing portion 202 from the current collector 2001, thereby forming a plurality of spaced active substance 2002 removal areas on the surface of the pole piece 200, so as to facilitate subsequent cutting of the entire pole piece 200 along the moving direction of the pole piece 200 to form a plurality of pole pieces 200 with active substance 2002 removal areas.

[0080] It can be understood that the active substance 2002 removal area includes a partial peeling area of the active substance 2002 and a complete peeling area of the active substance 2002.

[0081] Please refer to Figure 2 In some embodiments, the pressing portion 202 is provided with a plurality of pressing portions 202, which are arranged at intervals along the axial direction L of the first core portion 201a. The axial direction L of the first core portion 201a corresponds to the width direction of the pole piece 200.

[0082] Through the plurality of pressing portions 202 arranged at intervals along the axial direction L of the first core portion 201a, the adhesive section 31 can be adhered to form a plurality of stepped active substance 2002 removal areas in the width direction of the pole piece 200, so as to facilitate subsequent cutting of the entire pole piece 200 along the width direction of the pole piece 200 to form a plurality of pole pieces 200 with active substance 2002 removal areas.

[0083] Please refer toFigure 2 With Figure 7 In some embodiments, a projection of the first protrusion 2021 on the surface of the main body part 201 is a first projection, and a projection of the second protrusion 2022 on the surface of the main body part 201 is a second projection; in the first direction X, the first projection protrudes on both sides of the first direction X relative to the second projection.

[0084] Exemplarily, as shown in Figure 2 or Figure 6 , the first direction X is the axial direction L of the first core part 201a; or, as shown in Figure 8 , the first direction X is the circumferential direction R of the first core part 201a.

[0085] The first protrusion 2021 protrudes on both sides of the first direction X relative to the second protrusion 2022, which enables the bonding section 311 to be bonded to form two step-shaped structures for removing the active material 2002 in the first direction X of the pole piece 200 when the top pressing part 202 presses the bonding section 311, so as to facilitate subsequent cutting of two pole pieces 200 each having a step-shaped structure along the first direction X of the entire pole piece 200, and improve the removal efficiency of the active material 2002 on the pole piece 200.

[0086] Please refer to Figure 6 In some embodiments, the top pressing part 202 is continuously arranged on the outer circumferential surface of the first core part 201a around the axial direction L of the first core part 201a.

[0087] Such an arrangement enables the pole piece 200 to form a continuous step-shaped active material 2002 removal area in the moving direction under the action of the bonding member 31 and the top pressing part 202, so as to facilitate subsequent cutting of the entire pole piece 200 to form a plurality of pole pieces 200 each having an active material 2002 removal area.

[0088] Please refer to Figure 2 With Figure 7 In some embodiments, the first height is D1, the second height is D2, and the following conditions are met: 20um≥D2-D1≥5um, and D2≥0.2mm. The conditions 20um≥D2-D1≥5um can avoid the following situations: the step height difference formed by the removal position of the active material 2002 is too large, reducing the situation that the first protrusion 2021 corresponds to a position of the pole piece 200 where the active material 2002 is not completely peeled off; and the step height difference is too small, leading to the situation that the first protrusion 2021 corresponds to a position of the pole piece 200 where the active material 2002 is completely peeled off. The condition D2≥0.2mm can reduce the situation that the bonding member 31 bonds the active material 2002 of the pole piece 200 at a position not corresponding to the top pressing part 202.

[0089] Please refer to Figure 9In some embodiments, the functional structure 20a comprises a third protrusion 2023 protruding from the outer circumferential surface of the first core 201a around the axial direction L of the first core 201a; along the radial direction of the first core 201a, the third protrusion 2023 protrudes from the outer circumferential surface of the first core 201a by a third height D3, which is less than the first height; the third protrusion 2023 is configured to be in contact with the active material 2002.

[0090] The portion of the pole piece 200 between the functional structure 20a and the other structure 20 is limited by the third protrusion 2023, so that the pole piece 200 can pass between the functional structure 20a and the other structure 20 in a flat posture, reducing the situation that the active material 2002 is not easily removed due to the folding of the pole piece 200, and the third protrusion 2023 can also drive the pole piece 200 to move along the preset direction P by friction. Compared with the top pressing portion 202, the third protrusion 2023 has a smaller height, so that the third protrusion 2023 exerts a smaller pressure on the pole piece 200, thereby limiting the flatness of the pole piece 200 without easily removing the active material 2002 corresponding to the third protrusion 2023 from the current collector 2001.

[0091] Please refer to Figure 10 For example, in embodiments in which both structures 20 are functional structures 20a, a portion of the pole piece 200 can be clamped between the third protrusions 2023 of the two functional structures 20a to limit the pole piece 200.

[0092] Please refer to Figure 11 In some embodiments, the adhesive 31 comprises a first adhesive 31a and a second adhesive 31b, a portion of the first adhesive 31a is disposed between the pole piece 200 and the first structure 21, and a portion of the second adhesive 31b is disposed between the pole piece 200 and the second structure 22.

[0093] When the first side 2003 and the second side 2004 of the pole piece 200 both have active materials 2002, the first structure 21 and the second structure 22 can cooperate with each other, so that the top pressing portion 202 of the first structure 21 presses a portion of the first adhesive 31a on the active material 2002 on one side of the current collector 2001, and the top pressing portion 202 of the second structure 22 presses a portion of the second adhesive 31b on the active material 2002 on the other side of the current collector 2001, when the adhesive sections 311 of the first adhesive 31a and the second adhesive 31b are away from the pole piece 200, the active materials 2002 on the two sides of the current collector 2001 can be removed at the same time, thereby realizing the removal of the active materials 2002 on both sides of the pole piece 200, and improving the processing efficiency of the pole piece 200.

[0094] In some embodiments, the adhesive 31 is a single-sided tape, and one side of the single-sided tape is adhesive.

[0095] The adhesive 31 has an adhesive side that can adhere to the active material 2002. When the structure 20 presses against the adhesive 31, the non-adhesive side of the adhesive 31 is in contact with the structure 20, so that after the adhesive 31 adheres to the active material 2002, the non-adhesive side is separated from the structure 20, reducing the risk that the adhesive 31 will not be easily separated from the structure 20 and affect subsequent processing.

[0096] In some embodiments, the adhesive segment 311 is a certain segment on the adhesive 31, and the adhesive segment 311 adheres to the active material 2002 by adhesion.

[0097] In some embodiments, the adhesive 31 has an adhesive area, and the adhesive area continuously extends along the length of the adhesive 31, and the adhesion of different areas is the same.

[0098] In some embodiments, the adhesive 31 has an adhesive area, and the adhesive area continuously extends along the length of the adhesive 31, and the adhesive segment 311 is a specific area on the adhesive 31, and the adhesion of this area is greater, which is sufficient to separate the active material 2002 from the current collector 2001, and the adhesion of other areas on the adhesive 31 is smaller or has no adhesion, which is not sufficient to separate the active material 2002 from the current collector 2001.

[0099] In some embodiments, the adhesive 31 includes hot melt adhesive. The pole piece processing device 100 further includes a heating member (not shown in the figure) disposed on the functional structure 20a, and used to heat the functional structure 20a.

[0100] The hot melt adhesive has no or small adhesion when not activated, so that the adhesive 31 is not easily adhered to other structures before being in contact with the functional structure 20a. When the adhesive 31 is in contact with the functional structure 20a, the heating member can heat the hot melt adhesive, thereby activating the adhesion of the hot melt adhesive, so that when the functional structure 20a presses against the adhesive segment 311, the adhesive segment 311 adheres to the active material 2002.

[0101] In some embodiments, the activation temperature of the hot melt adhesive is 70°C-150°C.

[0102] In some embodiments, the room temperature adhesion of the adhesive segment 311 is F1, and satisfies: 0.05N / mm≤F1≤1N / mm, which is conducive to separating the active material 2002 at the corresponding position of the pole piece 200 by the adhesive segment 311, while reducing the risk of separating the active material 2002 that is not pressed but contacted by the adhesive segment 311, and reducing the probability of false separation.

[0103] Exemplarily, the room temperature adhesive force F1 of the adhesive section 311 is any one of 0.05 N / mm, 0.1 N / mm, 0.15 N / mm, 0.2 N / mm, 0.25 N / mm, 0.3 N / mm, 0.35 N / mm, 0.4 N / mm, 0.45 N / mm, 0.5 N / mm, 0.55 N / mm, 0.6 N / mm, 0.65 N / mm, 0.7 N / mm, 0.75 N / mm, 0.8 N / mm, 0.85 N / mm, 0.9 N / mm, 0.95 N / mm and 1 N / mm.

[0104] In some embodiments, 0.1 N / mm ≤ F1 ≤ 0.6 N / mm, which is further advantageous for the active substance 2002 at the corresponding position of the pole piece 200 of the adhesive section 311, while reducing the risk of peeling off the active substance 2002 that is not pressed but contacted by the adhesive section 311, and reducing the probability of false peeling.

[0105] In some embodiments, the at least one structural member 20 is heated so that the adhesive section 311 in contact with the structural member 20 is thermally activated, and the adhesive force of the adhesive section 311 that is thermally activated is defined as F2, which satisfies: 0.05 N / mm ≤ F2 ≤ 1 N / mm, which is advantageous for the active substance 2002 at the corresponding position of the pole piece 200 of the adhesive section 311, while reducing the risk of peeling off the active substance 2002 that is not pressed but contacted by the adhesive section 311, and reducing the probability of false peeling.

[0106] Exemplarily, the adhesive force F2 of the adhesive section 311 that is thermally activated is any one of 0.05 N / mm, 0.1 N / mm, 0.15 N / mm, 0.2 N / mm, 0.25 N / mm, 0.3 N / mm, 0.35 N / mm, 0.4 N / mm, 0.45 N / mm, 0.5 N / mm, 0.55 N / mm, 0.6 N / mm, 0.65 N / mm, 0.7 N / mm, 0.75 N / mm, 0.8 N / mm, 0.85 N / mm, 0.9 N / mm, 0.95 N / mm and 1 N / mm.

[0107] In some embodiments, 0.1 N / mm ≤ F2 ≤ 0.6 N / mm. This is further advantageous for the active substance 2002 at the corresponding position of the pole piece 200 of the adhesive section 311, while reducing the risk of peeling off the active substance 2002 that is not pressed but contacted by the adhesive section 311, and reducing the probability of false peeling.

[0108] In some embodiments, the test method of the adhesive force is as follows: the adhesive 31 is pasted on a steel plate in an environment at 25°C, the adhesive 31 is peeled off from the steel plate at 180° by using a tensile testing machine, and when the tension value on the tensile testing machine is stable during the gradual separation of the adhesive 31 from the steel plate, the adhesive force of the adhesive 31 is obtained. For details, refer to GB / T 2790-1995 “Adhesives - Determination of 180° peel strength - Flexible to rigid materials”.

[0109] Referring to Figure 12 In some embodiments, the adhesive 31 comprises a base film 312 and an adhesive layer 313 arranged in a stack, the thickness of the base film 312 is H1, and the thickness of the adhesive layer 313 is H2, which satisfy 0.01mm≤H1≤0.1mm and 0.005mm≤H2≤0.1mm.

[0110] 0.01mm≤H1≤0.1mm, so that the adhesive 31 has a certain strength and deformation capacity to deform towards the pole piece 200 when the top pressing part 202 presses, and the adhesive 31 is not easy to break and damage when deformed; 0.005mm≤H2≤0.1mm, so that the adhesive 31 has a certain thickness to ensure sufficient adhesion, and the adhesive 31 is not easy to be too thick to reduce the mispeeling situation.

[0111] In some embodiments, the base film 312 is a polyethylene film, a polypropylene film, a polyester film, or a polyimide film.

[0112] Referring to Figure 13 In some embodiments, the two structural parts 20 are respectively a first structural part 21 and a second structural part 22, and the first structural part 21 is a functional structural part 20a. The first structural part 21 is configured to move towards or away from the second structural part 22, the first structural part 21 presses the adhesive section 311 towards the pole piece 200 by moving towards the second structural part 22, so that the adhesive section 311 adheres to the active substance 2002; the first structural part 21 moves away from the second structural part 22, so that the adhesive section 311 carries the adhered active substance 2002 away from the current collector 2001.

[0113] For example, the moving direction of the first structural part 21 is in a second direction Z. The second direction Z is perpendicular to a preset direction P of the movement of the pole piece 200, and the second direction Z is consistent with the thickness direction of the pole piece 200.

[0114] The functional structure 20a is moved close to the second structure 22, so that the top pressing part 202 of the functional structure 20a presses the bonding section 311 to the pole piece 200, so that the active substance 2002 of the pole piece 200 under the pressure of the bonding section 311 can be bonded to the bonding section 311; then the functional structure 20a is moved away from the second structure 22, so that the active substance 2002 of the pole piece 200 corresponding to the bonding section 311 can be taken away from the current collector 2001.

[0115] In some embodiments, the bonding member 31 has tension during the transmission process, and when the first structure 21 moves away from the pole piece 200, the bonding section 311 moves away from the pole piece 200 under the action of the tension, and then the bonded active substance 2002 is taken away from the current collector 2001.

[0116] In some embodiments, the second structure 22 is fixedly arranged.

[0117] In some embodiments, the pole piece processing device 100 further comprises a linear driving source for driving the first structure 21 to move, which is a conventional arrangement in the technical field, and will not be described here.

[0118] Please refer to Figure 14 In some embodiments, both structures 20 are functional structures 20a; the two structures 20 are arranged opposite to each other along the thickness direction of the pole piece 200; the second structure 22 is configured to move in the direction close to or away from the first structure 21. Both the first structure 21 and the second structure 22 can move relative to the pole piece 200.

[0119] When the top pressing part 202 of the first structure 21 presses the bonding section 311 to the pole piece 200, the first protrusion 2021 of the second structure 22 is opposite to the first protrusion 2021 of the first structure 21 along the thickness direction of the pole piece 200, the second protrusion 2022 of the second structure 22 is opposite to the second protrusion 2022 of the first structure 21 along the thickness direction of the pole piece 200, and the top pressing part 202 of the first structure 21 and the top pressing part 202 of the second structure 22 clamp the pole piece 200 and the bonding section 311.

[0120] The first structure 21 and the second structure 22 can be close to each other, so that the first protrusion 2021 of the first structure 21 and the first protrusion 2021 of the second structure 22 clamp the pole piece 200 and the adhesive section 311, and the adhesive section 311 adheres the active substance 2002 on the pole piece 200; and so that the second protrusion 2022 of the first structure 21 and the second protrusion 2022 of the second structure 22 clamp the pole piece 200 and the adhesive section 311, and the adhesive section 311 adheres the active substance 2002 on the pole piece 200. Through the joint action of the top pressing part 202 of the first structure 21 and the top pressing part 202 of the second structure 22, the adhesive section 311 is more convenient to adhere and remove the active substance 2002.

[0121] In some embodiments, the pole piece processing device 100 further comprises a linear driving source for driving the second structure 22 to move, which is a conventional arrangement in the technical field, and will not be described herein.

[0122] Please refer to Figure 14 In some embodiments, when the first structure 21 and the second structure 22 are close to each other, the first adhesive 31a is pressed by the top pressing part 202 of the first structure 21 to press the adhesive section 311 of the first adhesive 31a on the active substance 2002 on one side of the pole piece 200, and at the same time, the second adhesive 31b is pressed by the top pressing part 202 of the second structure 22 to press the adhesive section 311 of the second adhesive 31b on the active substance 2002 on the other side of the pole piece 200; when the first structure 21 and the second structure 22 are away from each other, the first adhesive 31a and the second adhesive 31b remove the active substance 2002 on both sides of the pole piece 200, so as to achieve the simultaneous removal of the active substance 2002 on both sides of the pole piece 200.

[0123] In some embodiments, after the pole piece processing device 100 removes part of the active substance 2002 on the surface of the pole piece 200, a groove 2005 is formed, and part of the current collector 2001 is exposed. As shown in Figure 1 The first protrusion 2021 and the second protrusion 2022 are generally cuboid structures, so as to form a step structure with a flat cross section on the pole piece 200; as shown in Figure 15 The first protrusion 2021 and the second protrusion 2022 are generally trapezoidal structures, so as to form a step structure with an inclined cross section on the pole piece 200.

[0124] In addition, those skilled in the art should understand that the above embodiments are only used to illustrate the present application, and are not used as a limitation to the present application, and as long as the above embodiments are within the spirit and scope of the present application, any suitable changes and variations made to the above embodiments are within the scope of the present application.

Claims

1. A pole piece processing apparatus characterized by, The pole piece processing device comprises: a transmission assembly configured to move the pole piece along a preset direction; two structural members, at least one of which is a functional structural member, wherein one of the functional structural members is configured to be movably arranged on a first side of the pole piece provided with active material, and the other structural member is configured to be arranged on a second side of the pole piece opposite to the first side, the functional structural member comprises a main body portion and a pressing portion protruding from a surface of the main body portion, the pressing portion comprises a first protruding portion and a second protruding portion, the second protruding portion is arranged on the first protruding portion, the first protruding portion protrudes from the surface of the main body portion by a first height, and the second protruding portion protrudes from the surface of the main body portion by a second height, the first height being smaller than the second height; an adsorption assembly comprising an adhesive member configured to be at least partially located between the functional structural member and the pole piece, the adhesive member comprising an adhesive segment, the functional structural member being configured to cooperate with the other structural member to press the adhesive segment against the pole piece, and the functional structural member being configured to press the adhesive segment against the pole piece by the pressing portion, so that the portion of the adhesive segment pressed by the pressing portion adheres to at least part of the active material at a corresponding position on the pole piece and carries the adhered active material away from the current collector of the pole piece, and the first protruding portion applies a smaller pressure to the adhesive segment than the second protruding portion.

2. The pole piece processing apparatus of claim 1, wherein The functional structural member is rotatably arranged, the main body portion is a first core portion, and the pressing portion protrudes from an outer circumferential surface of the first core portion, the first height is a height by which the first protruding portion protrudes from the outer circumferential surface of the first core portion in a radial direction of the first core portion, and the second height is a height by which the second protruding portion protrudes from the outer circumferential surface of the first core portion in the radial direction of the first core portion.

3. The pole piece processing apparatus of claim 2, wherein The two structural members are a first structural member and a second structural member, and the first structural member is the functional structural member, and the second structural member comprises a second core portion rotatably arranged; When the pressing portion presses the adhesive segment against the pole piece, a portion of the outer circumferential surface of the second core portion is opposite to the first protruding portion in a thickness direction of the pole piece, and the pressing portion and the portion of the outer circumferential surface of the second core portion clamp the pole piece and the adhesive segment.

4. The pole piece processing apparatus of claim 2, wherein The two structural members are both the functional structural member, and the two structural members are configured to be arranged opposite to each other in the thickness direction of the pole piece; The two structural members are a first structural member and a second structural member, and when the pressing portion of the first structural member presses the adhesive segment against the pole piece, the first protruding portion of the second structural member is opposite to the first protruding portion of the first structural member in the thickness direction of the pole piece, the second protruding portion of the second structural member is opposite to the second protruding portion of the first structural member in the thickness direction of the pole piece, and the pressing portion of the first structural member and the pressing portion of the second structural member clamp the pole piece and the adhesive segment.

5. The pole piece processing apparatus of claim 4, wherein The adhesive member includes a first adhesive member and a second adhesive member, a part of the first adhesive member is arranged between the pole piece and the first structural member, and a part of the second adhesive member is arranged between the pole piece and the second structural member.

6. The pole piece processing apparatus of claim 2, wherein The pressing parts are arranged in multiple, and are arranged at intervals around the axial direction of the first core part. The pressing parts are arranged continuously around the outer circumferential surface of the first core part.

7. The pole piece processing apparatus of claim 1, wherein The two structural members are a first structural member and a second structural member, the first structural member is the functional structural member, the first structural member is configured to move towards or away from the second structural member, and the first structural member presses the adhesive segment towards the pole piece by moving towards the second structural member, so that the adhesive segment adheres to the active material; The first structural member moves away from the second structural member, so that the adhesive segment carries the adhered active material away from the current collector.

8. The pole piece processing apparatus of claim 7, wherein Both of the two structural members are the functional structural members, and the two structural members are configured to be arranged oppositely along the thickness direction of the pole piece. When the first structural member presses the adhesive segment towards the pole piece, the first protrusion of the second structural member is opposite to the first protrusion of the first structural member along the thickness direction of the pole piece, the second protrusion of the second structural member is opposite to the second protrusion of the first structural member along the thickness direction of the pole piece, and the pressing part of the first structural member and the pressing part of the second structural member clamp the pole piece and the adhesive segment.

9. The pole piece processing apparatus of any one of claims 1 to 8, wherein, The first height is D1, and the second height is D2, and the following conditions are met: 20um≥D2-D1≥5um, and D2≥0.2mm.

10. The pole piece processing apparatus of any one of claims 1 to 8, wherein, The adhesive member includes hot melt adhesive, and the pole piece processing device further includes a heating member arranged on the functional structural member and used for heating the functional structural member.

11. The pole piece processing apparatus of any one of claims 1 to 8, wherein The projection of the first protrusion on the surface of the main body part is a first projection, and the projection of the second protrusion on the surface of the main body part is a second projection; in the first direction, the first projection protrudes on both sides of the first direction relative to the second projection.

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