Cutting device, battery cell manufacturing device, and manufacturing method

Abstract

The present application provides a cutting device, a battery cell manufacturing device, and a manufacturing method. The cutting device comprises a first hot melt knife, a second hot melt knife and a driving mechanism; the first hot melt knife comprises a first knife body and a first knife edge which are connected to each other; the second hot melt knife comprises a second knife body and a second knife edge which are connected to each other; the driving mechanism is connected to the first hot melt knife and the second hot melt knife and is configured to drive the first hot melt knife and the second hot melt knife to approach each other or move away from each other. The first knife edge works with the second knife edge to cut, by hot melting, an object to be cut.

Description

Cutting device, battery cell preparation device and preparation method

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 2023116073162, filed on November 27, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a cutting device, a battery cell preparation device and a preparation method. Background Art

[0004] A laminated battery consists of a laminated cell and a casing; the laminated cell is mounted within the casing. During the production of laminated cells, a hot melt knife is used to cut the separators between adjacent laminated cells to form the feed and end cuts for the separators. However, after these cells are fabricated into a laminated battery, the anode electrode may come into contact with the cathode or casing, causing a short circuit or corrosion leakage, thereby shortening the battery's service life.

[0005] Summary of the Invention

[0006] The main technical problem solved by the present application is to provide a cutting device, a battery cell preparation device and a preparation method; in order to solve the problem that when a hot-melt flat-edge knife is used to hot-melt cut the diaphragm, the feed incision and the tail incision of the diaphragm are easily prone to defects such as warping and folding.

[0007] To address the aforementioned technical issues, the first technical solution employed in this application is to provide a cutting device comprising: a first hot melt blade, a second hot melt blade, and a drive mechanism. The first hot melt blade comprises a first blade body and a first blade connected to each other; the second hot melt blade comprises a second blade body and a second blade connected to each other; and the drive mechanism is connected to both the first and second hot melt blades and configured to drive the first and second hot melt blades toward or away from each other. The first and second blades, when engaged, are configured to thermally melt and sever an object to be cut.

[0008] In this way, the first and second hot-melt blades approach each other, allowing them to heat-seal the object to be cut between the first and second blades. Because the first and second hot-melt blades simultaneously heat-seal the object to be cut, the cutting temperature is higher, allowing the object to be cut quickly and reducing contact time with the object. This results in a smoother cut, thereby minimizing the risk of warping or folding. Furthermore, the forces exerted on the object by the first and second hot-melt blades offset each other, resulting in a more even force distribution. Consequently, when the first and second hot-melt blades separate, the cut is smoother, minimizing the risk of warping or folding.

[0009] In some embodiments, the first blade includes a plurality of first teeth and a first opening between two adjacent first teeth; the second blade includes a plurality of second teeth and a second opening between two adjacent second teeth; and when the first and second blades cooperate, the plurality of first teeth are inserted into the plurality of second openings, and the plurality of second teeth are inserted into the plurality of first openings. Thus, the plurality of first teeth are inserted into the plurality of second openings, and the plurality of second teeth are inserted into the plurality of first openings, so that the incision formed on the object to be cut is a broken line incision.

[0010] In some embodiments, the shape of the first teeth is the same as the shape of the second opening, and the shape of the second teeth is the same as the shape of the first opening. In this way, by inserting multiple first teeth into multiple second openings and multiple second teeth into multiple first openings, the incision of the object to be cut is a broken line incision.

[0011] In some embodiments, the shape of the first tooth portion is the same as the shape of the second tooth portion, so that the first tooth portion is easily inserted into the second opening and the second tooth portion is easily inserted into the first opening.

[0012] In some embodiments, the size of the first tooth portion is the same as the size of the second tooth portion. In this way, the shape and size are the same, which facilitates the manufacture of the first tooth portion and the second tooth portion.

[0013] In some embodiments, the first tooth portion includes a first connecting surface and a second connecting surface connected to each other; the first connecting surface and the second connecting surface are both connected to the first blade body. In this way, the first hot melt blade and the second hot melt blade can form a broken line incision when they cooperate, and the structures of the first tooth portion and the second tooth portion are simplified, making the first tooth portion and the second tooth portion easier to manufacture.

[0014] In some embodiments, the orthographic projections of the first and second teeth on the first plane are each a triangle, a rectangle, or a square; the first plane intersects the plane of the first hot melt knife. Thus, when the first and second teeth are triangular, they are sharper and easier to cut.

[0015] In some embodiments, the shape of the first tooth portion is different from the shape of the second tooth portion.

[0016] In some embodiments, the first tooth portion includes a first connecting surface and a second connecting surface that are in contact and connected; the first connecting surface and the second connecting surface are both in contact and connected with the first blade body; two adjacent first tooth portions are separated; the first connecting surface of a first tooth portion, the partial surface of the first blade body located between a first tooth portion and an adjacent first tooth portion, and the second connecting surface of another adjacent first tooth portion are sequentially in contact and connected to form a first opening. In this way, the shape of the first tooth portion can be pointed (also called triangular). A trapezoidal opening (also called a trapezoidal opening) can be formed between two adjacent first tooth portions; the corresponding second tooth portion is in the shape of a trapezoid (also called a trapezoidal platform).

[0017] In order to solve the above technical problems, the second technical solution provided by the present application is: to provide a preparation device for a battery cell, the preparation device includes a rolling mechanism and a cutting device, the rolling mechanism is configured to stack and roll the first cathode electrode sheet, the first diaphragm, the anode electrode sheet, the second diaphragm and the second cathode electrode sheet in sequence to form a battery cell preform; there is a disconnection between the multiple anode electrode sheets. The first hot melt knife and the second hot melt knife of the cutting device are configured to approach each other from opposite sides of the battery cell preform, hot melt the first diaphragm and the second diaphragm from the disconnection, and seal the end of the anode electrode sheet. In this way, the end of the anode electrode sheet can be sealed by using the cut first and second diaphragms, thereby reducing the exposure of the end of the anode electrode sheet. After the prefabricated battery cell is prepared into a battery, it can prevent the anode electrode sheet from contacting the cathode electrode sheet or the battery shell, which may cause a short circuit in the battery.

[0018] In order to solve the above technical problems, the third technical solution provided by the present application is: to provide a method for preparing a battery cell, the preparation method comprising: forming a battery cell preform; the battery cell preform comprises a first cathode electrode sheet, a first diaphragm, an anode electrode sheet, a second diaphragm and a second cathode electrode sheet stacked in sequence, with a disconnection between the multiple anode electrode sheets. The battery cell preform is passed between the first hot melt knife and the second hot melt knife of the cutting device; the first hot melt knife and the second hot melt knife of the cutting device are brought close to each other, the first diaphragm and the second diaphragm are hot-melted and cut off from the disconnection, and the end of the anode electrode sheet is sealed. In this way, the end of the anode electrode sheet can be sealed using the cut first and second diaphragms, thereby reducing the exposure of the end of the anode electrode sheet. After the prefabricated battery cell is prepared into a battery, it can prevent the anode electrode sheet from contacting the cathode electrode sheet or the battery shell, thereby preventing the battery from short-circuiting. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] FIG1 is a schematic structural diagram of a cutting device provided by the present application;

[0021] FIG2 is a side view of a first hot melt knife and a second hot melt knife provided by the present application;

[0022] FIG3 is a top view of a first hot melt knife and a second hot melt knife provided by the present application;

[0023] FIG4 is a perspective view of the first hot melt knife or the second hot melt knife in FIG3;

[0024] FIG5 is a top view of another first hot melt knife and a second hot melt knife provided by the present application;

[0025] FIG6 is a top view of a first hot melt knife and a second hot melt knife provided by the present application;

[0026] FIG7 is a perspective view of the first hot melt knife or the second hot melt knife in FIG6;

[0027] FIG8 is a top view of a first hot melt knife and a second hot melt knife provided by the present application;

[0028] FIG9 is a top view of another first hot melt knife or second hot melt knife provided by the present application;

[0029] FIG10 is a perspective view of the first hot melt knife in FIG9;

[0030] FIG11 is a simplified structural diagram of a battery cell manufacturing apparatus provided in the present application;

[0031] FIG12 is a flow chart of the method for preparing the battery cell provided in the present application.

[0032] In the figure: 1. cutting device; 11. first hot melt knife; 11a. first knife body; 11b. first blade; 111. first opening; 112. first tooth portion; 1121. first connecting surface; 1122. second connecting surface; 1123. third connecting surface; 11c. first surface; 12. second hot melt knife; 12a. second surface; 12b. second blade; 121. second tooth portion; 122. second opening; 12c. second knife body; 13. driving mechanism; 14. mounting frame; 2. rolling mechanism; 21. cathode rolling mechanism; 22. anode rolling mechanism; 3. anode electrode sheet; 4. first diaphragm; 5. second diaphragm; 6. first cathode electrode sheet; 7. cathode conveying mechanism; 8. second cathode electrode sheet; 9. battery cell preform. DETAILED DESCRIPTION

[0033] The following describes the embodiments of the present application in detail with reference to the accompanying drawings.

[0034] In the following description, for the purpose of explanation rather than limitation, specific details such as specific system structures, interfaces, and technologies are provided to facilitate a thorough understanding of the present application.

[0035] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0036] The terms "first," "second," and "third" in this application are used only for descriptive purposes and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of such features. In the description of this application, "multiple" means at least two, for example, two, three, etc., unless otherwise specifically defined. All directional indications in the embodiments of this application (such as up, down, left, right, front, back...) are only used to explain the relative positional relationship, movement, etc. between the components under a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications also change accordingly. In addition, the terms "including" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products, or devices.

[0037] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0038] In related technologies, a laminated battery comprises a laminated cell and a housing. The laminated cell is mounted within the housing. The laminated cell comprises two separators, multiple cathodes, and an anode plate positioned between the two separators. The two separators and the anode plate form a laminate structure, with the cathodes positioned in the gaps of the laminate structure and alternately connected to the two separators.

[0039] The applicant discovered that when producing laminated cells, using a hot-melt flat-edge knife to heat-seal the separators of adjacent laminated cells to form the separator feed and tail cuts can easily cause defects such as warping and folding in the feed and tail cuts, exposing the anode electrode. When these laminated cells are made into laminated batteries, the anode electrode can easily come into contact with the cathode or the battery casing, causing short circuits or corrosion leakage in the laminated battery, thereby shortening the battery's service life.

[0040] In order to solve the problem that when a hot-melt flat-edge knife is used to hot-melt cut the diaphragm, the feed incision and the tail incision of the diaphragm are easily warped, folded, and other defects are generated. An embodiment of the present application provides a cutting device comprising two hot-melt knives. The two hot-melt knives of the cutting device cooperate to cut the object to be cut using the principle of hot melting. Since the two hot-melt knives clamp the diaphragms from both sides of the diaphragms of adjacent battery cells and perform hot-melt cutting, the diaphragm can easily form a coating on the anode electrode at the incision.

[0041] Referring to Figures 1 to 4 , the cutting device 1 includes a first hot melt blade 11, a second hot melt blade 12, and a drive mechanism 13. The first hot melt blade 11 includes a first blade body 11a and a first blade edge 11b connected to each other; the second hot melt blade 12 includes a second blade body 12c and a second blade edge 12b connected to each other. The drive mechanism 13 is connected to both the first and second hot melt blades 11, 12 and is configured to drive the first and second hot melt blades 11, 12 toward or away from each other. When the first blade edge 11b and the second blade edge 12b cooperate, they are configured to thermally melt and sever the object to be cut.

[0042] In this way, the first hot melt knife 11 and the second hot melt knife 12 are close to each other, and the object to be cut between the first blade 11b and the second blade 12b can be cut by hot melting. Because the first hot melt knife 11 and the second hot melt knife 12 are cutting the object to be cut at the same time, the cutting temperature is higher, which can quickly cut the object to be cut, reduce the contact time with the object to be cut, and make the incision of the object to be cut smoother, thereby reducing the probability of the object to be cut warping or folding. In addition, the forces exerted on the object to be cut by the first hot melt knife 11 and the second hot melt knife 12 offset each other, making the force on the object to be cut more uniform; then, when the first hot melt knife 11 and the second hot melt knife 12 separate, the incision of the object to be cut is smoother, thereby reducing the problem of warping or folding of the object to be cut.

[0043] When cutting the laminated diaphragm, the first hot melt knife 11 and the second hot melt knife 12 clamp the diaphragm from both sides and perform hot melt cutting, so that the diaphragms on both sides fit together before melting, making it easier to form a coating on the anode electrode at the incision.

[0044] The first hot melt blade 11 and the second hot melt blade 12 are both made of materials that can withstand high temperatures (referred to as high-temperature resistant materials). The high-temperature resistant material can be ceramic or metal. For example, the metal can be a single element of copper, iron, aluminum, or the like. Another example is an alloy of the above single elements. In some examples, the cutting device further includes a heating device for heating the first hot melt blade 11 and the second hot melt blade 12. For example, the heating device can be a heating rod structure, a heating wire structure, or the like.

[0045] The first blade body 11a and the first blade 11b are fixedly connected, for example, the first blade body 11a and the first blade 11b are an integral structure. The second blade body 12c and the second blade 12b are fixedly connected, for example, the first blade body 11a and the first blade 11b are an integral structure.

[0046] The drive mechanism 13 is connected to both the first hot melt blade 11 and the second hot melt blade 12; for example, the drive mechanism 13 is connected to both the first blade body 11a of the first hot melt blade 11 and the second blade body 12c of the second hot melt blade 12. The drive mechanism 13 may include two telescopic mechanisms, each connected to the first hot melt blade 11 and the second hot melt blade 12, such that when the two telescopic mechanisms are extended, the first hot melt blade 11 and the second hot melt blade 12 are brought closer to each other. In some examples, the cutting device further includes a mounting frame 14, on which the first hot melt blade 11, the second hot melt blade 12, and the drive mechanism 13 are mounted.

[0047] The object to be cut can be an object that can be cut by a hot melt knife. The object to be cut can be a film, such as a single film, or two laminated films (for ease of description, the two films may be referred to as a first film and a second film). The object to be cut can also be a plastic plate, a diaphragm (such as the first diaphragm and the second diaphragm described below), etc.

[0048] In some examples, when the cutting device is used to cut the first and second films, the first hot melt blade 11 and the second hot melt blade 12 cooperate to heat-melt and cut the first and second films. This allows the first and second films to be cut while also sealing the cuts in the first and second films. In this way, the first and second hot melt blades 11 and 12 both cut the first and second films and seal the cuts in the first and second films.

[0049] In some embodiments, referring to FIG5 , the first blade 11b is disposed away from the first surface 11c of the first blade body 11a and the second blade 12b is disposed away from the second surface 12a of the second blade body 12c, and both the first surface 11c and the second surface 12a are planes, so that the incision of the object to be cut is a straight line.

[0050] In some embodiments, referring to Figures 2 to 4 , a first surface 11c of the first blade 11b, which is distal to the first blade body 11a, and a second surface 12a of the second blade 12b, which is distal to the second blade body 12c, are disposed opposite each other. The first surface 11c and the second surface 12a are both non-planar and can mate with each other, thereby forming a non-linear incision on the object to be cut.

[0051] When the first and second hot melt blades 11 and 12 are used to heat-melt and cut the first and second films, the non-linear cuts in the first and second films can be simultaneously cut and sealed. This increases the contact area between the first and second films, improving the adhesion between them and enhancing the sealing effect. It also reduces problems such as warping and folding of the first and second films.

[0052] The first surface 11c and the second surface 12a are both non-planar and can fit together; it can be understood that when the first hot melt knife 11 and the second hot melt knife 12 are close to each other, the first surface 11c and the second surface 12a can cooperate with each other and can hot-melt cut the object to be cut.

[0053] For example, the non-planar surface may be a curved surface, and the corresponding non-straight incision of the object to be cut is a curved incision. For example, the curved surface may be an arc surface, a spherical surface, or the like.

[0054] As another example, referring to Figures 3 and 4 , the non-planar surface can be a zigzag-shaped surface, and the corresponding non-linear incision of the object to be cut is a zigzag incision. A zigzag-shaped surface can be understood as a surface formed by connecting multiple planes end to end; for example, the zigzag-shaped surface can be a V-shaped surface, or multiple V-shaped surfaces connected together, or an M-shaped surface; or, as described below, a zigzag-shaped surface can form a zigzag incision.

[0055] In some embodiments, the first blade 11b includes a plurality of first teeth 112 and a first opening 111 located between two adjacent first teeth 112; the second blade 12b includes a plurality of second teeth 121 and a second opening 122 located between two adjacent second teeth 121. When the first blade 11b and the second blade 12b cooperate, the plurality of first teeth 112 are inserted into the plurality of second openings 122, and the plurality of second teeth 121 are inserted into the plurality of first openings 111. In this way, by inserting the plurality of first teeth 112 into the plurality of second openings 122 and the plurality of second teeth 121 into the plurality of first openings 111, the incision made on the object to be cut is a broken line incision.

[0056] In some examples, the plurality of first teeth 112 are arranged along a first direction X; the plurality of second teeth 121 are arranged along the first direction X. The first direction X can be the length direction or the width direction of the first hot melt blade 11 ; that is, the first direction X is related to the shape of the first hot melt blade 11 .

[0057] When the first blade 11b and the second blade 12b cooperate, since the first and second hot melt blades 11 and 12 utilize the principle of thermal melting to cut the object, a gap may exist between the first tooth portion 112 and the second opening 122, and a gap may exist between the second tooth portion 121 and the first opening 111. The width of the gap can be selected based on the thickness of the object to be cut; for example, the width of the gap may be 0.25-0.5 times the thickness of the membrane to be cut.

[0058] There may not be a gap between the first tooth portion 112 and the second opening 122, and there may not be a gap between the second tooth portion 121 and the first opening 111. The following description uses an example in which there is no gap between the first tooth portion 112 and the second opening 122, and no gap between the second tooth portion 121 and the first opening 111, when the first hot melt blade 11 and the second hot melt blade 12 are engaged.

[0059] In some embodiments, referring to Figures 3, 4, and 6-8, the shape of the first tooth portion 112 is the same as the shape of the second opening 122, and the shape of the second tooth portion 121 is the same as the shape of the first opening 111. This allows the first tooth portion 112 to be inserted into the second opening 122 with a smaller gap between them; and the second tooth portion 121 to be inserted into the first opening 111 with a smaller gap between them.

[0060] In some embodiments, referring to Figures 3, 4, 6, and 7, the dimensions of the first tooth portion 112 are the same as the dimensions of the second tooth portion 121. Thus, the first tooth portion 112 and the second tooth portion 121 have the same shape and dimensions, facilitating the manufacture of the first tooth portion 112 and the second tooth portion 121; for example, the first tooth portion 112 and the second tooth portion 121 can be manufactured using a single manufacturing process or a single mold.

[0061] In some embodiments, referring again to Figures 3, 4, 6, and 7, the first tooth portion 112 includes a first connecting surface 1121 and a second connecting surface 1122 connected to each other; the first connecting surface 1121 and the second connecting surface 1122 are both connected to the first blade body 11a. In this way, when the first hot melt knife 11 and the second hot melt knife 12 cooperate, a broken line incision can be formed on the object to be cut; the structure of the first tooth portion 112 and the second tooth portion 121 is also simplified, making it easier to manufacture the first tooth portion 112 and the second tooth portion 121. The shape and size of the second tooth portion 121 are the same as those of the first tooth portion 112, and the corresponding first opening 111 corresponds to the second tooth portion 121, and the second opening 122 corresponds to the first tooth portion 112. Therefore, the descriptions of the first opening 111, the second opening 122, and the second tooth portion 121 can all refer to the relevant description of the first tooth portion 112.

[0062] The first tooth portion 112 and the first opening 111 may be formed in various shapes according to whether the first connection surface 1121 , the second connection surface 1122 , and adjacent first connection surfaces 1121 and second connection surfaces 1122 are in contact with each other.

[0063] For example, the first tooth portion 112 can be pointed (also called triangular); that is, the orthographic projection of the first tooth portion 112 on the second plane is a triangle. A V-shaped opening can be formed between two adjacent first tooth portions 112; that is, the orthographic projection of the first opening 111 on the second plane is a triangle. The second plane is parallel to the plane of the first hot melt blade 11. Since the first tooth portion 112 and the second tooth portion 121 have the same shape and structure, the corresponding second tooth portion 121 is also pointed, and the second opening 122 is also V-shaped.

[0064] Continuing with Figures 3 and 4 , in the first tooth portion 112, the first connecting surface 1121 is in contact with the second connecting surface 1122. Both the first connecting surface 1121 and the second connecting surface 1122 are in contact with the first blade body 11a. The first connecting surface 1121 of one first tooth portion 112 is in contact with the second connecting surface 1122 of another adjacent first tooth portion 112, forming a first opening 111.

[0065] In some examples, the first connecting surface 1121 and the second connecting surface 1122 are symmetrically arranged, so that the orthographic projection of the first tooth portion 112 on the second plane is an isosceles triangle or an equilateral triangle.

[0066] As another example, the shape of the first tooth portion 112 can be a trapezoid (also called a trapezoidal trapezoid); that is, the orthographic projection of the first tooth portion 112 on the second plane is a trapezoid. A trapezoidal opening (also called a trapezoidal opening) can be formed between two adjacent first tooth portions 112; that is, the orthographic projection of the first opening 111 on the second plane is a trapezoid. Since the first tooth portion 112 and the second tooth portion 121 have the same shape and structure, the corresponding second tooth portion 121 is also a trapezoid, and the second opening 122 is also a trapezoidal opening.

[0067] 6 and 7 , in the first tooth portion 112, the first connecting surface 1121 and the second connecting surface 1122 are in contact and connected via a third contact surface. Both the first connecting surface 1121 and the second connecting surface 1122 are in contact and connected with the first blade body 11a. The first connecting surface 1121 of one first tooth portion 112, the portion of the surface of the first tooth portion 112 between the first tooth portion 112 and the adjacent first tooth portion 112, and the second connecting surface 1122 of the adjacent first tooth portion 112 are sequentially in contact and connected to form a first opening 111.

[0068] In some examples, the first connecting surface 1121 and the second connecting surface 1122 are symmetrically arranged, so that the orthographic projection of the first tooth portion 112 on the second plane is an isosceles trapezoid.

[0069] In some embodiments, as shown in FIG2 , the orthographic projections of the first tooth portion 112 and the second tooth portion 121 on a first plane are each a triangle, a rectangle, or a square; the first plane intersects the plane of the first hot melt knife 11. Thus, the triangular shape makes the first tooth portion 112 and the second tooth portion 121 sharper and easier to cut.

[0070] The orthographic projections of the first tooth portion 112 and the second tooth portion 121 on the first plane are both one of a triangle, a rectangle, or a square; it can be understood that the orthographic projections of the first connecting surface 1121 or the second connecting surface 1122 of the first tooth portion 112 on the first plane are both one of a triangle, a rectangle, or a square. For example, the orthographic projections of the first tooth portion 112 and the second tooth portion 121 on the first plane are both triangular. For another example, the orthographic projections of the first tooth portion 112 and the second tooth portion 121 on the first plane are both rectangular. For another example, the orthographic projections of the first tooth portion 112 and the second tooth portion 121 on the first plane are both square.

[0071] In some embodiments, referring to FIG8 , the shape of the first tooth portion 112 is the same as that of the second tooth portion 121, but the size of the first tooth portion 112 is different from that of the second tooth portion 121. The shape of the second tooth portion 121 is the same as that of the first tooth portion 112, the first opening 111 corresponds to the second tooth portion 121, and the second opening 122 corresponds to the first tooth portion 112; therefore, the descriptions of the first opening 111, the second opening 122, and the second tooth portion 121 can all refer to the description of the first tooth portion 112, but the sizes can be designed according to requirements.

[0072] Exemplarily, the first tooth portion 112 includes a first connecting surface 1121, a third connecting surface 1123, and a second connecting surface 1122, which are sequentially connected. The first connecting surface 1121 and the second connecting surface 1122 are both connected to the first blade body 11a. In the first direction, the first connecting surfaces 1121 of the first tooth portions 112 have different sizes. As a result, the orthographic projections of the first tooth portions 112 on the second plane are all trapezoidal, with the upper surfaces of the trapezoids varying in size (for example, as shown in FIG8 , the upper surfaces of the trapezoids increase in size from bottom to top).

[0073] In some embodiments, referring to FIG. 9 and FIG. 10 , the shape of the first tooth portion 112 is different from the shape of the second tooth portion 121 .

[0074] In some embodiments, referring again to Figures 9 and 10 , the first tooth portion 112 includes a first connecting surface 1121 and a second connecting surface 1122 that are in contact and connected; both the first connecting surface 1121 and the second connecting surface 1122 are in contact and connected with the first blade body 11a; two adjacent first tooth portions 112 are separated; the first connecting surface 1121 of one first tooth portion 112, the portion of the surface of the first blade body 11a between one first tooth portion 112 and the adjacent first tooth portion 112, and the second connecting surface 1122 of the adjacent first tooth portion 112 are sequentially in contact and connected to form a first opening 111. This allows the first tooth portion 112 to be pointed (also called triangular); that is, the orthographic projection of the first tooth portion 112 on the second plane is a triangle; and the corresponding second opening 122 is a V-shaped opening. A trapezoidal opening (also called a trapezoidal opening) can be formed between two adjacent first tooth portions 112; that is, the orthographic projection of the first opening 111 on the second plane is a trapezoid; the corresponding second tooth portion 121 is a trapezoid (also called a trapezoidal platform).

[0075] The first opening 111 corresponds to the second tooth portion 121, and the second opening 122 corresponds to the first tooth portion 112. Therefore, the description of the second opening 122 can refer to the description of the first tooth portion 112, and the description of the second tooth portion 121 can refer to the description of the first opening.

[0076] An embodiment of the present application provides a cell preparation device for preparing laminated cells, which can be used to prepare laminated batteries. Referring to Figure 11 , the preparation device includes a rolling mechanism 2 and a cutting device 1. The rolling mechanism 2 is configured to sequentially stack and roll a first cathode electrode sheet 6, a first separator 4, an anode electrode sheet 3, a second separator 5, and a second cathode electrode sheet 8 to form a cell preform 9; the multiple anode electrode sheets 3 have a disconnection point between them. The first and second hot melt blades 11 and 12 of the cutting device 1 are configured to approach each other from opposite sides of the cell preform 9, heat-seal the first and second separators 4 and 5 at the disconnection point, and seal the ends of the anode electrode sheet 3. This allows the ends of the anode electrode sheet 3 to be sealed using the severed first and second separators 4 and 5, thereby reducing exposure. After the prefabricated cell is prepared into a battery, it can prevent the anode electrode sheet 3 from contacting the cathode electrode sheet or the battery casing, which could cause a short circuit.

[0077] Since the structures of the first blade and the second blade are different, the incision of the first diaphragm 4 and the incision of the second diaphragm 5 after cutting are different. For example, the incision of the first diaphragm 4 and the incision of the second diaphragm 5 after cutting can form a straight line incision. For example, the incision of the first diaphragm 4 and the incision of the second diaphragm 5 after cutting can form a non-straight line incision (for example, a curved incision, or a broken line incision).

[0078] In some examples, the rolling mechanism 2 may include a cathode rolling mechanism 21 and an anode rolling mechanism 22. The anode rolling mechanism 22 is configured to roll the first separator 4, multiple anode pole pieces 3, and the second separator 5 into a whole (which may be referred to as a first rolled body). The cathode rolling mechanism 21 alternately rolls the first cathode pole piece 6 and the second cathode pole piece 8 onto the first separator 4 and the second separator 5 of the first rolled body, respectively, to form a battery cell preform 9. The disconnection point is located between two adjacent anode pole pieces 3.

[0079] In some examples, the preparation device also includes a cathode conveying mechanism 7, which is configured to cut the first cathode pattern and the second cathode pattern into a first cathode electrode piece 6 and a second cathode electrode piece 8, and convey the first cathode electrode piece 6 and the second cathode electrode piece 8 to the cathode rolling mechanism 21 for rolling with the first rolling body.

[0080] In some examples, the rolling mechanism may be a set of cooperating roller structures.

[0081] The embodiment of the present application provides a method for preparing a battery cell. Referring to FIG12 , the method includes step S100 and step S200.

[0082] Step S100, forming a battery cell preform; the battery cell preform includes a first cathode electrode sheet, a first separator, an anode electrode sheet, a second separator, and a second cathode electrode sheet stacked in sequence; the anode electrode sheet has a disconnection portion for forming spaced-apart sub-anode electrode sheets;

[0083] Step S200: Pass the cell preform between the first hot melt knife and the second hot melt knife of the cutting device; bring the first hot melt knife and the second hot melt knife of the cutting device close to each other, hot-melt the first diaphragm and the second diaphragm from the disconnection point of the anode electrode sheet, and seal the end of the sub-anode electrode sheet 3.

[0084] In this way, the ends of the anode plate 3 can be sealed by the cut first and second separators 4 and 5, thereby reducing the exposure of the ends of the anode plate 3. After the prefabricated battery cell is prepared into a battery, it can prevent the anode plate 3 from contacting the cathode plate or the battery casing, which may cause a short circuit in the battery.

[0085] The above description is only an implementation method of the present application and does not limit the scope of patent protection of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the scope of patent protection of the present application.

Claims

1. A cutting device, wherein: include: A first hot melt knife, comprising a first knife body and a first knife edge connected to each other; A second hot melt knife, comprising a second knife body and a second knife edge connected to each other; a driving mechanism connected to both the first hot melt knife and the second hot melt knife, and configured to drive the first hot melt knife and the second hot melt knife to move closer to each other or away from each other; Wherein, when the first blade cooperates with the second blade, they are configured to hot-melt cut off the object to be cut.

2. The cutting device according to claim 1, wherein: The first blade includes a plurality of first teeth and a first opening between two adjacent first teeth; the second blade includes a plurality of second teeth and a second opening between two adjacent second teeth; when the first blade cooperates with the second blade, the plurality of first teeth are inserted into the plurality of second openings, and the plurality of second teeth are inserted into the plurality of first openings.

3. The cutting device according to claim 2, wherein: The shape of the first tooth portion is the same as that of the second opening, and the shape of the second tooth portion is the same as that of the first opening.

4. The cutting device according to claim 2 or 3, wherein: The shape of the first tooth portion is the same as the shape of the second tooth portion.

5. The cutting device according to any one of claims 2 to 4, wherein: The size of the first tooth portion is the same as the size of the second tooth portion.

6. The cutting device according to any one of claims 2 to 5, wherein: The first tooth portion includes a first connecting surface and a second connecting surface that are connected; the first connecting surface and the second connecting surface are both connected to the first blade body.

7. The cutting device according to any one of claims 2 to 6, wherein: The orthographic projection shapes of the first tooth portion and the second tooth portion on the first plane are both one of a triangle, a rectangle or a square; the first plane intersects with the plane where the first hot melt knife is located.

8. The cutting device according to claim 3, wherein: The shape of the first tooth portion is different from the shape of the second tooth portion.

9. The cutting device according to claim 8, wherein: The first tooth portion includes a first connecting surface and a second connecting surface that are in contact and connected; the first connecting surface and the second connecting surface are both in contact and connected with the first blade body; two adjacent first tooth portions are separated; the first connecting surface of a first tooth portion, a partial surface of the first blade body located between the first tooth portion and an adjacent first tooth portion, and the second connecting surface of another adjacent first tooth portion are in contact and connected in sequence to form the first opening.

10. A battery cell preparation device, wherein: include; A rolling mechanism is configured to stack and roll the first cathode electrode sheet, the first separator, the anode electrode sheet, the second separator and the second cathode electrode sheet in sequence to form a battery cell preform; a plurality of anode electrode sheets are provided with disconnections; and, The cutting device as described in any one of claims 1 to 9, wherein the first hot melt knife and the second hot melt knife of the cutting device are configured to approach each other from opposite sides of the battery cell preform, hot-melt cut the first diaphragm and the second diaphragm from the disconnection point, and seal the end of the anode electrode sheet.

11. A method for preparing a battery cell, wherein: include: forming a battery cell preform; The battery cell preform comprises a first cathode electrode sheet, a first separator, an anode electrode sheet, a second separator and a second cathode electrode sheet which are sequentially stacked, and a plurality of anode electrode sheets are provided with disconnections; Make the battery cell preform pass through the first hot melt knife and the second hot melt knife of the cutting device as described in any one of claims 1 to 9; make the first hot melt knife and the second hot melt knife of the cutting device approach each other, hot-melt cut the first diaphragm and the second diaphragm from the disconnection point, and seal the end of the anode electrode sheet.

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