Cutting device and preparation device and preparation method of battery cell

Abstract

The invention provides a cutting device, a battery cell preparation device and a battery cell preparation method. The cutting device comprises a first hot melting cutter, a second hot melting cutter and a driving mechanism. The first hot melting cutter comprises a first cutter body and a first cutting edge which are connected with each other. The second hot melting cutter comprises a second cutter body and a second blade which are connected with each other; the driving mechanism is connected with the first hot melting knife and the second hot melting knife and is configured to drive the first hot melting knife and the second hot melting knife to get close to each other or get away from each other. When the first cutting edge and the second cutting edge are matched, the first cutting edge and the second cutting edge are configured to cut an object to be cut through hot melting.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to a cutting device, a preparation device and a preparation method for a battery cell. Background Art

[0002] A laminated battery includes a laminated battery cell and a housing; the laminated battery cell is installed in the housing. When producing the laminated battery cell, a hot melt knife is used to hot melt cut the separator between adjacent laminated battery cells to form a feed cut and a finishing cut of the separator. However, after the battery cell is made into a laminated battery, the anode electrode may contact the cathode or the housing, resulting in a short circuit or corrosion and leakage of the laminated battery, thereby affecting the service life of the battery. Summary of the Invention

[0003] The main technical problem to be solved by the present application is to provide a cutting device, a preparation device and a preparation method for a battery cell; in order to solve the problem that when a hot melt flat knife is used to hot melt cut a separator, defects such as warping and folding are likely to occur in the feed cut and the finishing cut of the separator.

[0004] To solve the above technical problem, the first technical solution adopted by the present application is: to provide a cutting device, the cutting device includes: a first hot melt knife, a second hot melt knife and a driving mechanism, the first hot melt knife includes a first knife body and a first blade connected to each other; the second hot melt knife includes a second knife body and a second blade connected to each other; the driving mechanism is connected to both 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 or separate from each other. Wherein, when the first blade and the second blade cooperate, they are configured to hot melt cut an object to be cut.

[0005] In this way, the first hot melt knife and the second hot melt knife approach each other, and the object to be cut located between the first blade and the second blade can be hot melt cut. Since the first hot melt knife and the second hot melt knife simultaneously hot melt cut the object to be cut, the temperature during cutting is relatively high, the object to be cut can be quickly cut off, the contact time with the object to be cut is reduced, and the cut of the object to be cut is relatively flat, thereby reducing the problem of warping and folding of the object to be cut. In addition, the forces exerted on the object to be cut by the first hot melt knife and the second hot melt knife cancel each other out, making the force on the object to be cut relatively uniform; then when the first hot melt knife and the second hot melt knife separate, the cut of the object to be cut is relatively flat, thereby reducing the problem of warping and folding of the object to be cut.

[0006] In some embodiments, the first blade includes a plurality of first tooth portions and first openings located between two adjacent first tooth portions; the second blade includes a plurality of second tooth portions and second openings located between two adjacent second tooth portions; when the first blade and the second blade cooperate, they are configured such that a plurality of first tooth portions are inserted into a plurality of second openings, and a plurality of second tooth portions are inserted into a plurality of first openings. In this way, a plurality of first tooth portions are inserted into a plurality of second openings, and a plurality of second tooth portions are inserted into a plurality of first openings, such that the cut of the object to be cut is a zigzag cut.

[0007] In some embodiments, the shape of the first tooth portion is the same as the shape of the second opening, and the shape of the second tooth portion is the same as the shape of the first opening. In this way, by inserting a plurality of first tooth portions into a plurality of second openings and a plurality of second tooth portions into a plurality of first openings, the cut of the object to be cut is a zigzag cut.

[0008] In some embodiments, the shape of the first tooth portion is the same as the shape of the second tooth portion. In this way, it is convenient for the first tooth portion to be inserted into the second opening and for the second tooth portion to be inserted into the first opening.

[0009] In some embodiments, the size of the first tooth portion is the same as the size of the second tooth portion. In this way, with the same shape and size, it is convenient to manufacture the first tooth portion and the second tooth portion.

[0010] In some embodiments, the first tooth portion includes a connected first connecting surface and second connecting surface; both the first connecting surface and the second connecting surface are connected to the first tool body. In this way, when the first hot melt knife and the second hot melt knife cooperate to form a zigzag cut; the structures of the first tooth portion and the second tooth portion are also simplified, making the first tooth portion and the second tooth portion easy to manufacture.

[0011] In some embodiments, 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 the plane where the first hot melt knife is located. In this way, when it is a triangle, the first tooth portion and the second tooth portion are relatively sharp and convenient for shearing.

[0012] In some embodiments, the shape of the first tooth portion is different from the shape of the second tooth portion.

[0013] In some embodiments, the first tooth portion includes a first connection surface and a second connection surface in contact connection; both the first connection surface and the second connection surface are in contact connection with the first tool body; adjacent two first tooth portions are separated; the first connection surface of one first tooth portion, a partial surface of the first tool body located between one first tooth portion and an adjacent first tooth portion, and the second connection surface of the other adjacent first tooth portion are sequentially in contact connection to enclose a first opening. In this way, the shape of the first tooth portion can be pointed (also can be called triangular). A trapezoidal opening (also can be called a trapezoidal mouth) can be formed between two adjacent first tooth portions; the corresponding second tooth portion is trapezoidal (also can be called a trapezoidal platform).

[0014] To solve the above technical problems, the second technical solution provided by this application is: to provide a preparation device for an electric core, the preparation device includes a rolling mechanism and a cutting device, the rolling mechanism is configured to sequentially stack and roll a first cathode electrode sheet, a first separator, an anode electrode sheet, a second separator, and a second cathode electrode sheet to form a core preform; there are disconnections between 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 core preform, hot melt cut the first separator and the second separator from the disconnection, and seal the ends of the anode electrode sheet. In this way, the ends of the anode electrode sheet can be sealed by using the cut first separator and second separator, so as to reduce the exposure of the ends of the anode electrode sheet. After the prefabricated core body is made into a battery, it can prevent the anode electrode sheet from contacting the cathode electrode sheet or the battery housing, resulting in the problem of battery short circuit.

[0015] To solve the above technical problems, the third technical solution provided by this application is: to provide a preparation method for an electric core, the preparation method includes: forming a core preform; the core preform includes a first cathode electrode sheet, a first separator, an anode electrode sheet, a second separator, and a second cathode electrode sheet arranged in sequence, and there are disconnections between multiple anode electrode sheets. Pass the core preform through between the first hot melt knife and the second hot melt knife of the cutting device; make the first hot melt knife and the second hot melt knife of the cutting device approach each other, hot melt cut the first separator and the second separator from the disconnection, and seal the ends of the anode electrode sheet. In this way, the ends of the anode electrode sheet can be sealed by using the cut first separator and second separator, so as to reduce the exposure of the ends of the anode electrode sheet. After the prefabricated core body is made into a battery, it can prevent the anode electrode sheet from contacting the cathode electrode sheet or the battery housing, resulting in the problem of battery short circuit. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings.

[0017] Figure 1 is a schematic structural view of the cutting device provided by the present application;

[0018] Figure 2 is a side view of the first hot melt knife and the second hot melt knife provided by the present application;

[0019] Figure 3 is a top view of a kind of first hot melt knife and second hot melt knife provided by the present application;

[0020] Figure 4 is Figure 3 a perspective view of the first hot melt knife or the second hot melt knife in

[0021] Figure 5 is a top view of another kind of first hot melt knife and second hot melt knife provided by the present application;

[0022] Figure 6 is a top view of yet another kind of first hot melt knife and second hot melt knife provided by the present application;

[0023] Figure 7 is Figure 6 a perspective view of the first hot melt knife or the second hot melt knife in

[0024] Figure 8 is a top view of yet another kind of first hot melt knife and second hot melt knife provided by the present application;

[0025] Figure 9 is a top view of yet another kind of first hot melt knife or second hot melt knife provided by the present application;

[0026] Figure 10 is Figure 9 a perspective view of the first hot melt knife in

[0027] Figure 11 is a schematic structural diagram of the preparation device of the battery cell provided by the present application;

[0028] Figure 12 is a flow chart of the preparation method of the battery cell provided by the present application.

[0029] In the figure: 1. Cutting device; 11. First hot melt knife; 11a. First knife body; 11b. First cutting edge; 111. First opening; 112. First tooth part; 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 cutting edge; 121. Second tooth part; 122. Second opening; 12c. Second knife body; 13. Driving mechanism; 14. Mounting rack; 2. Rolling mechanism; 21. Cathode rolling mechanism; 22. Anode rolling mechanism; 3. Anode plate; 4. First separator; 5. Second separator; 6. First cathode plate; 7. Cathode conveying mechanism; 8. Second cathode plate; 9. Core preform. Detailed implementation mode

[0030] The following will, with reference to the accompanying drawings of the specification, elaborate on the solutions of the embodiments of the present application in detail.

[0031] In the following description, specific details such as specific system structures, interfaces, technologies, etc. are presented for the purpose of illustration rather than limitation, so as to understand the present application thoroughly.

[0032] The following will, with reference to the accompanying drawings in the embodiments of the present application, clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present application.

[0033] The terms "first", "second", and "third" in the present application are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", and "third" may explicitly or implicitly include at least one of such features. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. All directional indications (such as up, down, left, right, front, back...) in the embodiments of the present application are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. 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 optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices.

[0034] References herein to "embodiments" mean that the particular features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0035] In the related art, a laminated battery includes a laminated battery cell and a housing; the laminated battery cell is installed in the housing. The laminated battery cell includes two separators, a plurality of cathodes, and an anode plate located between the two separators; the two separators and the anode plate form a laminated structure, and the plurality of cathodes are respectively located in a plurality of gaps of the laminated structure and are alternately connected to the two separators.

[0036] The applicant has found that when manufacturing a laminated battery cell, using a single hot-melt flat knife to hot-melt cut the separators of adjacent laminated battery cells to form an inlet cut and a finishing cut of the separator easily causes defects such as warping and folding at the inlet cut and the finishing cut, thus exposing the anode plate. Then, when the laminated battery cell is fabricated into a laminated battery, it is likely to cause the anode plate to contact the cathode or the housing, resulting in a short circuit or corrosion and leakage of the laminated battery, thereby affecting the service life of the battery.

[0037] To solve the problem that when using a single hot-melt flat knife to hot-melt cut the separator, it is easy to cause defects such as warping and folding at the inlet cut and the finishing cut of the separator. An embodiment of the present application provides a cutting device including 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 separator from both sides of the separator of adjacent battery cells and perform hot-melt cutting, it is easy for the separator to form a coating on the anode plate at the cut.

[0038] See Figures 1 - 4 , the cutting device 1 includes a first hot-melt knife 11, a second hot-melt knife 12, and a driving mechanism 13. The first hot-melt knife 11 includes a first knife body 11a and a first knife edge 11b that are connected to each other; the second hot-melt knife 12 includes a second knife body 12c and a second knife edge 12b that are connected to each other; the driving mechanism 13 is connected to both the first hot-melt knife 11 and the second hot-melt knife 12 and is configured to drive the first hot-melt knife 11 and the second hot-melt knife 12 to approach or move away from each other. When the first knife edge 11b cooperates with the second knife edge 12b, it is configured to hot-melt cut the object to be cut.

[0039] In this way, the first hot melt knife 11 and the second hot melt knife 12 approach each other, and the object to be cut located between the first blade 11b and the second blade 12b can be hot melt cut off. Since the first hot melt knife 11 and the second hot melt knife 12 simultaneously perform hot melt cutting on the object to be cut, the temperature during cutting is relatively high, the object to be cut can be quickly cut off, the contact time with the object to be cut is reduced, and the cut of the object to be cut is relatively flat, thereby reducing the probability of the object to be cut warping and 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 cancel each other out, making the force on the object to be cut relatively uniform; then when the first hot melt knife 11 and the second hot melt knife 12 separate, the cut of the object to be cut is relatively flat, thereby reducing the problem of the object to be cut warping and folding.

[0040] When cutting the laminated separator, the first hot melt knife 11 and the second hot melt knife 12 respectively clamp the separator from both sides of the separator and perform hot melt cutting, so that the two sides of the separator are attached to each other before fusing, making it easier to form a coating on the anode electrode at the cut.

[0041] The materials of the first hot melt knife 11 and the second hot melt knife 12 are both materials that can withstand high temperatures (which can be called high-temperature-resistant materials). The high-temperature-resistant material can be ceramics or metals. For example, the metal can be a single element such as copper, iron, aluminum, etc. Another example is that the metal can be an alloy of the above single elements. In some examples, the cutting device further includes a heating device for heating the first hot melt knife 11 and the second hot melt knife 12. For example, the heating device can be a heating rod structure, a heating wire structure, etc.

[0042] The first knife body 11a and the first blade 11b are fixedly connected. For example, the first knife body 11a and the first blade 11b are of an integral structure. The second knife body 12c and the second blade 12b are fixedly connected. For example, the first knife body 11a and the first blade 11b are of an integral structure.

[0043] The driving mechanism 13 is connected to both the first hot melt knife 11 and the second hot melt knife 12; for example, the driving mechanism 13 is connected to the first knife body 11a of the first hot melt knife 11 and the second knife body 12c of the second hot melt knife 12. The driving mechanism 13 can include two telescopic mechanisms, and the two telescopic mechanisms are respectively connected to the first hot melt knife 11 and the second hot melt knife 12, so that when the two telescopic mechanisms extend, the first hot melt knife 11 and the second hot melt knife 12 approach each other. In some examples, the cutting device further includes a mounting frame 14, and the first hot melt knife 11, the second hot melt knife 12, and the driving mechanism 13 are all mounted on the mounting frame 14.

[0044] 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 stacked films (for the sake of illustration, the two films can be referred to as the first film and the second film). The object to be cut can also be a plastic plate, a diaphragm (such as the first diaphragm and the second diaphragm hereinafter), etc.

[0045] In some examples, when cutting the first film and the second film using a cutting device; when the first hot melt knife 11 and the second hot melt knife 12 cooperate, they perform hot melt cutting on the first film and the second film; while cutting the first film and the second film, the cut of the first film and the cut of the second film can also be sealed. In this way, the first hot melt knife 11 and the second hot melt knife 12 have the function of cutting the first film and the second film, and also have the function of sealing the cut of the first film and the cut of the second film.

[0046] In some embodiments, referring to Figure 5 , the first surface 11c of the first blade 11b away from the first tool body 11a is disposed opposite to the second surface 12a of the second blade 12b away from the second tool body 12c, and both the first surface 11c and the second surface 12a are flat surfaces. Such that the cut of the object to be cut is a straight cut.

[0047] In some embodiments, referring to Figures 2 - 4 , the first surface 11c of the first blade 11b away from the first tool body 11a is disposed opposite to the second surface 12a of the second blade 12b away from the second tool body 12c, and both the first surface 11c and the second surface 12a are non - flat surfaces and can fit together. Such that the cut of the object to be cut is a non - straight cut.

[0048] When performing hot melt cutting on the first film and the second film using the first hot melt knife 11 and the second hot melt knife 12; while cutting the first film and the second film, the non - straight cut of the first film and the non - straight cut of the second film can also be sealed. In this way, the contact area between the first film and the second film can be increased, making the adhesion between the first film and the second film larger, so that the sealing effect between the first film and the second film is better. It can also reduce problems such as warping and folding of the first film and the second film.

[0049] Both the first surface 11c and the second surface 12a are non - flat surfaces and can fit together; it can be understood that when the first hot melt knife 11 and the second hot melt knife 12 approach 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.

[0050] Exemplarily, the non - flat surface can be a curved surface, and the corresponding non - straight cut of the object to be cut is a curved cut. For example, the curved surface can be an arc surface, a spherical surface, etc.

[0051] Also exemplarily, referring toFigure 3 and Figure 4 The non-planar surface can be a surface with a broken-line shape, and the non-linear cut of the object to be cut is a broken-line cut. The surface with a broken-line shape can be understood as a surface formed by a plurality of planes connected end to end in sequence; for example, the surface with a broken-line shape can be a V-shaped surface, and for another example, the surface with a broken-line shape can be a plurality of connected V-shaped surfaces, and for another example, the surface with a broken-line shape can be an M-shaped surface; for another example, the surface with a broken-line shape introduced in the following text can form a broken-line cut.

[0052] In some embodiments, the first cutting edge 11b includes a plurality of first teeth 112 and a first opening 111 located between two adjacent first teeth 112; the second cutting edge 12b includes a plurality of second teeth 121 and a second opening 122 located between two adjacent second teeth 121; when the first cutting edge 11b and the second cutting edge 12b cooperate, they are configured such that a plurality of first teeth 112 are inserted into a plurality of second openings 122, and a plurality of second teeth 121 are inserted into a plurality of first openings 111. In this way, by inserting a plurality of first teeth 112 into a plurality of second openings 122 and a plurality of second teeth 121 into a plurality of first openings 111, the cut of the object to be cut is a broken-line cut.

[0053] 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 of the first hot melt knife 11 or the width direction; that is to say, the first direction X is related to the shape of the first hot melt knife 11.

[0054] When the first cutting edge 11b and the second cutting edge 12b cooperate, since the first hot melt knife 11 and the second hot melt knife 12 cut the object to be cut by using the hot melt principle. Then, there may be a gap between the first teeth 112 and the second openings 122, and there may be a gap between the second teeth 121 and the first openings 111; the width of this gap can be selected according to the thickness of the object to be cut; for example, the width of the gap can be 0.25 - 0.5 times the thickness of the diaphragm to be cut.

[0055] There may be no gap between the first teeth 112 and the second openings 122, and there may be no gap between the second teeth 121 and the first openings 111. In the following, an example is given in which there is no gap between the first teeth 112 and the second openings 122 and there is no gap between the second teeth 121 and the first openings 111 when the first hot melt knife 11 and the second hot melt knife 12 cooperate.

[0056] In some embodiments, refer to Figure 3 , Figure 4 and Figures 6 - 8, the shape of the first tooth part 112 is the same as that of the second opening 122, and the shape of the second tooth part 121 is the same as that of the first opening 111. In this way, the first tooth part 112 is inserted into the second opening 122, and the gap between the first tooth part 112 and the second opening 122 is small; the second tooth part 121 is inserted into the first opening 111, and the gap between the second tooth part 121 and the first opening 111 is small.

[0057] In some embodiments, refer to Figure 3 , Figure 4 , Figure 6 and Figure 7 , the size of the first tooth part 112 is the same as that of the second tooth part 121. In this way, the shapes and sizes of the first tooth part 112 and the second tooth part 121 are the same, which is convenient for manufacturing the first tooth part 112 and the second tooth part 121; for example, the first tooth part 112 and the second tooth part 121 are made by one preparation process or one kind of mold.

[0058] In some embodiments, continue to refer to Figure 3 , Figure 4 , Figure 6 and Figure 7 , the first tooth part 112 includes a connected first connection surface 1121 and a second connection surface 1122; both the first connection surface 1121 and the second connection surface 1122 are connected to the first tool body 11a. In this way, after the first hot melt knife 11 and the second hot melt knife 12 are matched, when the object to be cut can form a broken line incision; it also simplifies the structures of the first tooth part 112 and the second tooth part 121, so as to facilitate the manufacturing of the first tooth part 112 and the second tooth part 121. Among them, the shape and size of the second tooth part 121 are the same as those of the first tooth part 112, and correspondingly, the first opening 111 corresponds to the second tooth part 121, and the second opening 122 corresponds to the first tooth part 112. Therefore, the descriptions of the first opening 111, the second opening 122, and the second tooth part 121 can all refer to the relevant descriptions of the first tooth part 112.

[0059] According to whether the first connection surface 1121, the second connection surface 1122, and the adjacent first connection surface 1121 and the second connection surface 1122 are in contact connection, various shapes can be formed between the first tooth part 112 and the first opening 111.

[0060] Exemplarily, the shape of the first tooth portion 112 may be pointed (also referred to as triangular); that is, the orthographic projection of the first tooth portion 112 on the second plane is a triangle. A V-shaped opening may 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 where the first hot melt knife 11 is located. Since the shapes and structures of the first tooth portion 112 and the second tooth portion 121 are the same, the corresponding second tooth portion 121 is also pointed, and the second opening 122 is also a V-shaped opening.

[0061] Continuing to refer to Figure 3 and Figure 4 , in the first tooth portion 112, the first connecting surface 1121 is in contact connection with the second connecting surface 1122, and both the first connecting surface 1121 and the second connecting surface 1122 are in contact connection with the first tool body 11a. The first connecting surface 1121 of one first tooth portion 112 is in contact connection with the second connecting surface 1122 of an adjacent other first tooth portion 112 to enclose a first opening 111.

[0062] 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.

[0063] Also exemplarily, the shape of the first tooth portion 112 may be a frustum shape (also referred to as a trapezoidal frustum); that is, the orthographic projection of the first tooth portion 112 on the second plane is a trapezoid. A frustum-shaped opening (also referred to as a trapezoidal opening) may 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 shapes and structures of the first tooth portion 112 and the second tooth portion 121 are the same, the corresponding second tooth portion 121 is also a frustum shape, and the second opening 122 is also a frustum-shaped opening.

[0064] Refer to Figure 6 and Figure 7 , in the first tooth portion 112, the first connecting surface 1121 is in contact connection with the second connecting surface 1122 through a third contact surface, and both the first connecting surface 1121 and the second connecting surface 1122 are in contact connection with the first tool body 11a. The first connecting surface 1121 of one first tooth portion 112, a partial surface of the first tooth portion 112 located between one first tooth portion 112 and an adjacent first tooth portion 112, and the second connecting surface 1122 of an adjacent other first tooth portion 112 are sequentially in contact connection to enclose 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 trapezoid.

[0066] In some embodiments, refer toFigure 2 The orthographic projection shapes of the first tooth part 112 and the second tooth part 121 on the first plane are both one of a triangle, a rectangle, or a square; the first plane intersects the plane where the first hot melt knife 11 is located. In this way, when it is a triangle, the first tooth part 112 and the second tooth part 121 are relatively sharp, facilitating cutting.

[0067] The orthographic projection shapes of the first tooth part 112 and the second tooth part 121 on the first plane are both one of a triangle, a rectangle, or a square; it can be understood that the orthographic projection shapes of the first connecting surface 1121 or the second connecting surface 1122 of the first tooth part 112 on the first plane are both one of a triangle, a rectangle, or a square. For example, the orthographic projection shapes of the first tooth part 112 and the second tooth part 121 on the first plane are both triangles. Another example is that the orthographic projection shapes of the first tooth part 112 and the second tooth part 121 on the first plane are both rectangles. Another example is that the orthographic projection shapes of the first tooth part 112 and the second tooth part 121 on the first plane are both squares.

[0068] In some embodiments, referring to Figure 8 , the shape of the first tooth part 112 is the same as the shape of the second tooth part 121, and the size of the first tooth part 112 is different from the size of the second tooth part 121. Among them, the shape of the second tooth part 121 is the same as the shape of the first tooth part 112, the first opening 111 corresponds to the second tooth part 121, and the second opening 122 corresponds to the first tooth part 112; therefore, the descriptions of the first opening 111, the second opening 122, and the second tooth part 121 can all refer to the relevant descriptions of the first tooth part 112, but the size is designed according to requirements.

[0069] Exemplarily, the first tooth part 112 includes a first connecting surface 1121, a third connecting surface 1123, and a second connecting surface 1122 connected in sequence; both the first connecting surface 1121 and the second connecting surface 1122 are connected to the first tool body 11a. Among them, in the first direction, the sizes of the first connecting surfaces 1121 of multiple first tooth parts 112 are different. In this way, the orthographic projections of multiple first tooth parts 112 on the second plane are all trapezoids, and the sizes of the upper surfaces of the trapezoids are different (for example, as Figure 8 shown, the sizes of the upper surfaces of multiple trapezoids increase sequentially from bottom to top).

[0070] In some embodiments, referring to Figure 9 and Figure 10 , the shape of the first tooth part 112 is different from the shape of the second tooth part 121.

[0071] In some embodiments, continue to refer to Figure 9 and Figure 10, the first tooth part 112 includes a first connection surface 1121 and a second connection surface 1122 that are in contact connection; both the first connection surface 1121 and the second connection surface 1122 are in contact connection with the first tool body 11a; adjacent two first tooth parts 112 are separated; the first connection surface 1121 of one first tooth part 112, a partial surface of the first tool body 11a located between one first tooth part 112 and an adjacent first tooth part 112, and the second connection surface 1122 of the adjacent other first tooth part 112 are sequentially in contact connection to enclose a first opening 111. In this way, the shape of the first tooth part 112 can be pointed (also can be called triangular); that is to say, the orthographic projection of the first tooth part 112 on the second plane is a triangle; the corresponding second opening 122 is a V-shaped opening. It enables a stepped opening (also can be called a trapezoidal opening) to be formed between adjacent two first tooth parts 112; that is to say, the orthographic projection of the first opening 111 on the second plane is a trapezoid; the corresponding second tooth part 121 is in a stepped shape (also can be called a trapezoidal platform).

[0072] The first opening 111 corresponds to the second tooth part 121, and the second opening 122 corresponds to the first tooth part 112. Therefore, the description of the second opening 122 can refer to the relevant description of the first tooth part 112, and the description of the second tooth part 121 can refer to the relevant description of the first opening.

[0073] An embodiment of the present application provides a preparation device for a battery cell. The preparation device is used to prepare a stacked battery cell, and this battery cell can be used to prepare a stacked battery. See Figure 11 , the preparation device includes a rolling mechanism 2 and a cutting device 1. The rolling mechanism 2 is configured to 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 in sequence to form a battery cell preform 9; there are disconnection points between multiple anode electrode sheets 3. The first hot melt knife 11 and the second hot melt knife 12 of the cutting device 1 are configured to approach each other from opposite sides of the battery cell preform 9, thermally cut the first separator 4 and the second separator 5 from the disconnection points, and seal the ends of the anode electrode sheet 3. In this way, the cut first separator 4 and second separator 5 can be used to seal the ends of the anode electrode sheet 3, thereby reducing the exposure of the ends of the anode electrode sheet 3. After the prefabricated battery cell body is made into a battery, it can prevent the anode electrode sheet 3 from contacting the cathode electrode sheet or the battery housing, resulting in the problem of battery short circuit.

[0074] Due to the different structures of the first cutting edge and the second cutting edge, the cut surfaces of the cut first separator 4 and the second separator 5 are different. For example, the cut surfaces of the cut first separator 4 and the second separator 5 can form a straight cut surface, and for another example, the cut surfaces of the cut first separator 4 and the second separator 5 can form a non-straight cut surface (such as a curved cut surface, or a broken line cut surface).

[0075] 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, the plurality of anode plates 3, and the second separator 5 into a whole (which may be referred to as the first rolled body); the cathode rolling mechanism 21 alternately rolls the first cathode plate 6 and the second cathode plate 8 on the first separator 4 and the second separator 5 of the first rolled body, respectively, to form a preform 9 of the battery cell. The break is located between two adjacent anode plates 3.

[0076] In some examples, the preparation device further includes a cathode conveying mechanism 7, which is configured to cut the first cathode pattern and the second cathode pattern into the first cathode plate 6 and the second cathode plate 8, and convey the first cathode plate 6 and the second cathode plate 8 to the cathode rolling mechanism 21 for rolling with the first rolled body.

[0077] In some examples, the rolling mechanism may be a set of cooperating roll structures.

[0078] Embodiments of the present application provide a method for preparing a battery cell. Refer to Figure 12 , the preparation method includes step S100 and step S200.

[0079] Step S100: Form a preform of the battery cell; the preform of the battery cell includes a first cathode plate, a first separator, an anode plate, a second separator, and a second cathode plate that are sequentially stacked; the anode plate has a break for forming sub-anode plates arranged at intervals;

[0080] Step S200: Pass the preform of the battery cell between a first hot melt knife and a second hot melt knife of the cutting device; move the first hot melt knife and the second hot melt knife of the cutting device closer to each other to thermally cut off the first separator and the second separator from the break of the anode plate, and seal the ends of the sub-anode plates 3.

[0081] In this way, the cut first separator 4 and second separator 5 can be used to seal the ends of the anode plate 3, thereby reducing the exposure of the ends of the anode plate 3. After the preform of the battery cell is made into a battery, it can prevent the anode plate 3 from contacting the cathode plate or the housing of the battery, resulting in the problem of battery short circuit.

[0082] The above is only the implementation manner of the present application, and does not limit the patent protection scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present application by the same token.

Claims

1. A cutting device, characterized in that, comprising: A first hot melt knife, including a first knife body and a first knife edge connected to each other; A second hot melt knife, including 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 approach or move away from each other; wherein, when the first knife edge cooperates with the second knife edge, it is configured to melt and cut an object to be cut.

2. The cutting device according to claim 1, characterized in that, The first knife edge includes a plurality of first tooth portions and a first opening located between two adjacent first tooth portions; the second knife edge includes a plurality of second tooth portions and a second opening located between two adjacent second tooth portions; when the first knife edge cooperates with the second knife edge, it is configured that the plurality of first tooth portions are inserted into the plurality of second openings, and the plurality of second tooth portions are inserted into the plurality of first openings.

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

4. The cutting device according to claim 3, characterized in that, The shape of the first tooth portion is the same as the shape of the second tooth portion.

5. The cutting device according to claim 4, characterized in that, The size of the first tooth portion is the same as the size of the second tooth portion.

6. The cutting device according to claim 5, characterized in that, The first tooth portion includes a first connecting surface and a second connecting surface connected to each other; both the first connecting surface and the second connecting surface are connected to the first knife body.

7. The cutting device according to any one of claims 4 to 6, characterized in that, The orthographic projection shapes of the first tooth portion and the second tooth portion on a 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, characterized in that, 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, characterized in that, The first tooth portion includes a first connecting surface and a second connecting surface in contact connection; both the first connecting surface and the second connecting surface are in contact connection with the first knife body; two adjacent first tooth portions are separated; the first connecting surface of one first tooth portion, a partial surface of the first knife body located between the one first tooth portion and an adjacent first tooth portion, and the second connecting surface of the adjacent other first tooth portion are sequentially in contact connection to enclose the first opening.

10. A device for preparing an electric core, characterized in that, comprising; A rolling mechanism, configured to sequentially stack and roll a first cathode electrode sheet, a first separator, an anode electrode sheet, a second separator and a second cathode electrode sheet to form an electric core preform; there are disconnections between multiple anode electrode sheets; and, The cutting device according to 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 prefabricated cell body, thermally cut the first separator and the second separator from the disconnection point, and seal the end of the anode tab.

11. A method for manufacturing a cell, characterized in that, comprising: forming a prefabricated cell body; the prefabricated cell body includes a first cathode tab, a first separator, an anode tab, a second separator, and a second cathode tab that are sequentially stacked, and there is a disconnection point between multiple anode tabs; passing the prefabricated cell body through the first hot melt knife and the second hot melt knife of the cutting device according to any one of claims 1 to 9; causing the first hot melt knife and the second hot melt knife of the cutting device to approach each other, thermally cutting the first separator and the second separator from the disconnection point, and sealing the end of the anode tab.

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