Film production method and film production equipment

Abstract

The present invention discloses a film-making method, including providing a metal foil: the metal foil is divided into a first coating area, a blank area and a second coating area, and the blank area is located between the first coating area and the second coating area; a first cutting: cutting the blank area at a preset distance, so that the blank area forms a hollow area and a connection area arranged at intervals; a second cutting: cutting the connection area, so that each connection area forms a first pole ear connected to the first coating area and a second pole ear connected to the second coating area, respectively, so as to form two pole pieces. In addition, a film-making device using the above-mentioned film-making method is also disclosed. The film-making method of the present invention improves the utilization rate of the metal foil by setting the blank area between the first coating area and the second coating area, cutting the blank area twice to form two pole pieces with pole ears; and the two cuttings can easily divide the first coating area and the second coating area into pole pieces with pole ears, thereby improving the cutting efficiency.

Description

Technical Field

[0001] The invention belongs to the field of lithium battery automation equipment, and in particular relates to a film making method. Background Art

[0002] The cell of a lithium battery is a winding body formed by winding the positive and negative electrodes and the separator in sequence. The tab is a metal conductor that leads the positive and negative electrodes from the cell. The tab is formed by welding or cutting on the electrode. Figure 1 As shown, the first coating area 11 and the second coating area 12 are located in the middle, and the blank areas 13 are located on both sides. The tabs 14 are cut out from the blank areas 13 on both sides, and then the first coating area 11 and the second coating area 12 are cut. The metal foil 10 produced by this film making method has not only low utilization rate, but also low cutting efficiency. Summary of the invention

[0003] The object of the present invention is to provide a film-making method and a film-making device which can save materials and improve efficiency.

[0004] To achieve the above object, the film making method of the present invention comprises providing a metal foil: the metal foil is divided into a first coating area, a blank area and a second coating area, and the blank area is located between the first coating area and the second coating area;

[0005] One-time cutting: cutting the blank area at a preset distance, so that the blank area forms hollow areas and connection areas arranged at intervals;

[0006] Secondary cutting: cutting the connection area so that each connection area forms a first pole ear connected to the first coating area and a second pole ear connected to the second coating area, thereby forming two pole pieces.

[0007] In one embodiment of the film-making method of the present invention, the primary cutting is performed using a knife die, and the shape of the knife die is the same as the shape of the hollowed-out area.

[0008] In one embodiment of the production method of the present invention, the primary cutting is performed by laser cutting, and the path of the laser cutting is the same as the edge shape of the hollow area.

[0009] In one embodiment of the tablet manufacturing method of the present invention, the secondary cutting uses a knife die, and the knife die divides the connection area into a first electrode tab and a second electrode tab, which are respectively connected to the first coating area and the second coating area.

[0010] In one embodiment of the manufacturing method of the present invention, the secondary cutting is performed by laser cutting, and the path of the laser cutting makes the first electrode tab and the second electrode tab formed have the same shape.

[0011] In one embodiment of the film making method of the present invention, the moving path of the laser beam between cutting two adjacent connecting areas passes through the hollow area.

[0012] In one embodiment of the sheet making method of the present invention, the direction of the secondary cutting is parallel to the length direction of the metal foil.

[0013] The present invention also provides a tablet-making device using the tablet-making method.

[0014] In summary, the production method of the present invention improves the utilization rate of metal foil by setting the blank area between the first coating area and the second coating area, and cutting the blank area twice to form two pole pieces with pole ears; and the two cuts can more easily divide the first coating area and the second coating area into pole pieces with pole ears, thereby improving the cutting efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of a film making method in the prior art;

[0016] Figure 2 is a schematic diagram of a first embodiment of a film-making method of the present invention;

[0017] Figure 3 It is a schematic diagram of another path of secondary cutting in the first embodiment of the film making method of the present invention;

[0018] Figure 4 2 is a schematic diagram of a second embodiment of the film-making method of the present invention;

[0019] Figure 5 It is a schematic diagram of reducing the difficulty of cutting by secondary cutting in the slice making method of the present invention;

[0020] In the figure: 100, metal foil; 110, first coating area; 120, blank area; 121, hollow area; 122, connection area; 1221, first pole ear; 1222, second pole ear; 130, second coating area; 140, pole piece. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0022] like Figure 2 As shown, the film making method of the present invention is mainly to realize the efficient formation of the tab on the substrate. The substrate generally includes a first coating area 110 and a second coating area 130 formed by coating the electrode slurry on the metal foil along the width direction, and no slurry is coated between the two coating areas, thereby forming a blank area. The blank area is used to form the tab.

[0023] The method of the present invention comprises the following steps:

[0024] (1) Providing a metal foil 100: The metal foil 100 is divided into a first coating area 110, a blank area 120 and a second coating area 130, wherein the blank area 120 is located between the first coating area 110 and the second coating area 130. The width of the first and second coating areas corresponds to the length of the battery cell wound by the formed electrode sheet. The blank area is used to form the electrode ear on the electrode sheet, so the width of the blank area is determined by the shape of the electrode ear and the cutting process. Depending on the shape of the electrode ear and the cutting process, the width of the blank area is 1 to 2 times the length of the electrode ear. Through the description of the subsequent cutting scheme, especially the secondary cutting scheme, it is easy to obtain the width of the blank area in combination with the specific battery cell specifications.

[0025] (2) One-time cutting: Cut the blank area 120 at a preset interval, so that the blank area 120 forms a hollow area 121 and a connection area 122 arranged at intervals. The interval between the blank areas can be determined according to the design structure of the battery cell.

[0026] (3) Secondary cutting: cutting the connection area 122 so that each connection area 122 forms a first electrode tab 1221 and a second electrode tab 1222 which are respectively connected to the first coating area 110 and the second coating area 130 , and the metal foil 100 forms two electrode sheets 140 .

[0027] The first cutting in step (2) can be performed by a die cutter or by laser cutting. When the first cutting is performed by a die cutter, the shape of the die cutter is the same as the shape of the hollow area 121. When the first cutting is performed by laser cutting, the path of the laser cutting is the same as the edge shape of the hollow area 121.

[0028] The shape of the hollow area 121 is determined according to the shape of the pole lug, which may be in the shape of a trapezoid, a rectangle, a square, etc. By replacing the corresponding cutting die or resetting the laser cutting path, pole lugs of different design structures can be conveniently cut.

[0029] The secondary cutting in step (3) can be performed by die cutting or laser cutting. When the secondary cutting is performed by die cutting, the shape of the die cutting is set according to the shape of the tab, and the connection area 122 is cut into two tabs of the same shape, which are respectively connected to the first coating area 110 and the second coating area 130.

[0030] When the secondary cutting is performed by laser cutting, the laser cutting path makes the first electrode tab 1221 and the second electrode tab 1222 have the same shape.

[0031] In the specific preparation method, Figure 2As shown, the metal foil 100 used in the film making method of the embodiment of the present invention is divided into a first coating area 110, a blank area 120 and a second coating area 130 along its length direction, and the blank area 120 is located between the first coating area 110 and the second coating area 130. The blank area 120 is cut in an offset manner to form a first pole ear 1221 and a second pole ear 1222, and the first and second pole ears are respectively connected to the first coating area 110 and the second coating area 130 to form two identical pole pieces. The method of this embodiment improves the utilization rate of the blank area 120, thereby improving the utilization rate of the metal foil 100.

[0032] Embodiment 1: Figure 2 , Figure 3 As shown, when the tab is selected as an isosceles trapezoid, the hollow area 121 and the connection area 122 formed after the first cutting are both parallelograms. The second cutting adopts laser cutting to cut the connection area 122 into two parts of the same shape, forming a first tab 1221 and a second tab 1222 in the shape of an isosceles trapezoid, which are connected to the first coating area 110 and the second coating area respectively. The path of the second cutting can be as follows Figure 2 The path ABCD shown in c can also be followed Figure 3 The path abcd shown in c is sufficient as long as the connection area 122 can be cut into two isosceles trapezoids of the same shape. After the secondary cutting, the metal foil 100 forms two pole pieces 140 with pole tabs. During the secondary cutting process, the laser beam moves between the two pole tab cuttings, that is, from Figure 2 Move the previous cut point D in c to the starting point A of the next cutting path, or Figure 3 When point d of the migration cutting process in c moves to point a of the next cutting process, its moving path passes through the hollow area 121, thereby avoiding damage to the foil material in the blank area.

[0033] Embodiment 2: Figure 4 As shown, when the tab is selected to be rectangular, the hollow area 121 and the connection area 122 formed after the first cutting are both rectangular. The second cutting cuts the connection area 122 into two rectangles of the same shape, and the first tab 1221 and the second tab 1222 are rectangular.

[0034] Embodiment three:

[0035] The metal foil 100 moves along the transmission direction at a certain speed. Although the metal foil 100 is transmitted at a uniform speed, the metal foil 100 still has fluctuations. Small fluctuations will cause deviations of the pole ears. Therefore, after the metal foil 100 is cut into two pole pieces with pole ears, the pole ears still need to be shaped.

[0036] In order to reduce the difficulty of cutting, the film making method of the present invention can quickly cut the metal foil 100 into two pole pieces with pole ears. The blank area 120 is cut at the same distance by a knife die or laser cutting method, so that the blank area 120 forms a hollow area 121 and a connection area 122 that are set at intervals. The interval distance of the first cutting is set according to the position of the pole ear. Since the metal foil 100 is transmitted at a uniform speed, the steps of the first cutting are started at the same time. Such a setting is convenient for controlling the work of the first cutting and also improves the speed of the first cutting. The shape of the connection area 122 formed after the first cutting is the same, and the same shape is convenient for identification before the second cutting, which is convenient for control, reduces the identification difficulty of the second cutting, and improves the cutting efficiency.

[0037] The secondary cutting only needs to divide the connection area 122 into two patterns of substantially the same shape, which are respectively connected to the first coating area 110 and the second coating area 130. Figure 5 As shown, the connection area 122 can be cut along the dividing line shown in 5c, which reduces the difficulty of secondary cutting and improves the cutting efficiency. The tabs are then shaped.

[0038] In the above embodiment, the width of the blank area is equal to the length of the formed tab. In other embodiments, the blank area can also be cut evenly along the length direction of the substrate to form two tabs of equal length. In this case, the width of the blank area should be equal to twice the length of the tab.

[0039] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A film-making method, characterized in that: include: Providing a metal foil material: the metal foil material is divided into a first coating area, a blank area, and a second coating area, wherein the blank area is located between the first coating area and the second coating area; One-time cutting: cutting the blank area at a preset distance, so that the blank area forms hollow areas and connection areas arranged at intervals; Secondary cutting: identifying the connection area, cutting the connection area, so that each connection area forms a first pole ear connected to the first coating area and a second pole ear connected to the second coating area, thereby forming two pole pieces.

2. The tableting method according to claim 1, wherein: The primary cutting adopts a cutting die, and the shape of the cutting die is the same as the shape of the hollowed-out area.

3. The tableting method according to claim 1, wherein: The primary cutting is performed by laser cutting, and the path of the laser cutting is the same as the edge shape of the hollow area.

4. The film-making method according to claim 1, characterized in that: The secondary cutting adopts a knife die, and the knife die divides the connection area into a first pole ear and a second pole ear, which are respectively connected to the first coating area and the second coating area.

5. The film-making method according to claim 1, characterized in that: The secondary cutting is performed by laser cutting, and the path of the laser cutting makes the first pole tab and the second pole tab formed have the same shape.

6. The tableting method according to claim 5, characterized in that: The moving path of the laser passing through the hollow area when cutting between two adjacent connection areas.

7. The film-making method according to claim 1, characterized in that: The secondary cutting direction is parallel to the length direction of the metal foil.

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