Laminating platform and laminating machine

Abstract

The utility model discloses a lamination platform and a lamination machine. The lamination platform comprises an object carrying platform and a pressing cutter, the object carrying platform is provided with an object carrying surface, and the object carrying surface is used for carrying the laminated core; the pressing cutter is arranged on the side, away from the object carrying face, of the stacked core, the pressing cutter comprises a pressing cutter body and a concave part, the pressing cutter body comprises a first surface facing the stacked core, and the concave part is formed in the first surface; the pressing cutter can move in the first direction, when the first surface of the pressing cutter makes contact with the stacked core, a hollow area is formed between the concave portion and the stacked core, and the first direction is perpendicular to the object carrying face. According to the technical scheme, cracks or powder falling on the edges of the pole pieces in the pressing process of the pressing cutter can be prevented, the stacked battery cells can be conveniently taken out from the object carrying platform, meanwhile, the heat dissipation effect of the object carrying platform can be improved, and convenience is provided for cleaning of the object carrying platform.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of lithium battery manufacturing equipment. More particularly, the present disclosure relates to a lamination machine. BACKGROUND

[0002] With the development of battery manufacturing technology, high-performance lithium batteries have been favored by the market. Among them, the cell is an important component of the lithium battery, which determines the key indicators such as capacity, cycle life, safety, etc. of the lithium battery. The manufacturing process of the lithium battery cell mainly includes winding and lamination. Among them, the lamination process is widely used due to its high space utilization, stable internal structure, high safety and other advantages.

[0003] In order to obtain the pole piece for manufacturing the cell, the positive electrode slurry and the negative electrode slurry prepared in advance are respectively extruded or sprayed onto the metal plate, and then subjected to drying, punching and other steps, to finally form the positive electrode sheet and the negative electrode sheet for lamination. During lamination, since the separator is continuous, the layers formed by the separator are in a Z shape, and the positive electrode sheet and the negative electrode sheet are sandwiched between two layers of separators. Therefore, during the lamination process, a special fixing device needs to be provided to fix the stacked pole pieces and separators during the lamination process, so as to prevent the pole pieces and separators from sliding accidentally during the lamination process, thereby affecting the lamination effect. Usually, a pressing knife is arranged at each corner of the lamination platform to press the corner of the pole piece and the separator, so as to press the layers of the lamination tightly and prevent sliding.

[0004] However, in actual production, the cutting edge of the edge of the pole piece is easily cracked or powdery after being pressed by the pressing knife, which affects the quality of the pole piece, and further affects the quality of the entire battery, resulting in a decrease in the yield. In addition, the loading platform of the traditional lamination platform is a complete plane, and the cell formed by lamination is not convenient to take out directly. Moreover, under such design, the heat dissipation effect of the loading platform is poor, and it is also not convenient to clean the loading platform.

[0005] The prior art provides a technical solution of a pressing knife and a lamination machine. The vertical section of the pressing knife adopts a Z-shaped structure, so that the pressing knife itself has a certain degree of deformation buffer. While satisfying the pressing of the pole piece and the separator, it can also prevent the pole piece from being damaged due to excessive instantaneous pressure.

[0006] However, the technical solution has some deficiencies. First, the Z-shaped structure of the pressing knife in the technical solution not only produces elastic deformation in the vertical direction when being pressed, but also produces horizontal thrust on the pole piece or diaphragm in close contact with it in the horizontal direction. At this time, the pole piece or diaphragm may produce relative displacement due to the horizontal thrust being greater than the maximum static friction. Or although the horizontal thrust is less than the maximum static friction, the static friction between the bottom surface of the pressing knife and the pole piece or diaphragm in close contact with it is too large due to the large thrust, resulting in damage to the pole piece or diaphragm. In addition, the technical solution does not improve the object carrying platform, and still has the above-mentioned various inconveniences.

[0007] Therefore, it is urgent to provide a lamination platform solution that prevents the pole piece and diaphragm from accidentally sliding by pressing downward during the lamination process, prevents cracks or powder loss at the edge of the pole piece during the pressing process, improves the product yield, and improves the object carrying platform of the lamination platform to facilitate the removal of the stacked battery cell from the object carrying platform, and facilitates heat dissipation and cleaning. Content of the utility model

[0008] In order to solve the technical problems mentioned above, the present disclosure proposes a lamination platform and a lamination machine in various aspects.

[0009] In a first aspect, the present disclosure provides a lamination platform for stacking a battery cell, the lamination platform comprising an object carrying platform and a pressing knife, wherein the object carrying platform has an object carrying surface for carrying the battery cell; the pressing knife is arranged on the side of the battery cell away from the object carrying surface, the pressing knife comprises a pressing knife body and a recess, the pressing knife body comprises a first surface facing the battery cell, and the recess is formed on the first surface; the pressing knife can move in a first direction, and when the first surface of the pressing knife is in contact with the battery cell, a hollow area is formed between the recess and the battery cell, and the first direction is perpendicular to the object carrying surface.

[0010] In some embodiments, a hollow part is recessed on the object carrying surface of the object carrying platform in the first direction, and the projection of the battery cell in the first direction covers the hollow part.

[0011] In some embodiments, the lamination platform further comprises a driving assembly, the pressing knife body comprises at least one through hole, a thread is arranged in the through hole, the pressing knife body is connected with the driving assembly through the through hole, and the driving assembly drives the pressing knife body to move in the first direction.

[0012] In a second aspect, the present disclosure provides a lamination machine, wherein the lamination machine is provided with any one of the lamination platforms disclosed herein.

[0013] By means of the lamination platform and the lamination machine as provided above, the lamination platform according to the embodiments of the present disclosure can prevent the edge of the pole piece from cracking or falling off powder during the pressing process by forming a recess on the first surface of the pressing tool body.

[0014] Further, according to one embodiment, by forming a hollow part on the object carrying platform, the stacked formed battery cell can be conveniently taken out from the object carrying platform, and meanwhile, the heat dissipation effect of the object carrying platform can be improved, and the cleaning of the object carrying platform is facilitated. BRIEF DESCRIPTION OF DRAWINGS

[0015] The above and other objects, features and advantages of the exemplary embodiments of the present disclosure will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0016] Figure 1 A schematic diagram of a lithium battery cell structure in a lamination process is shown;

[0017] Figure 2 A schematic diagram of the overall structure of the lamination platform according to the embodiments of the present disclosure is shown;

[0018] Figure 3 A schematic diagram of the structure of the pressing tool according to the embodiments of the present disclosure is shown;

[0019] Figure 4 A schematic diagram of the structure of the object carrying platform and the pressing tool according to the embodiments of the present disclosure is shown;

[0020] Figure 5a - Figure 5d A schematic diagram of the structure of the object carrying platform according to the embodiments of the present disclosure is shown;

[0021] Figure 6 A schematic diagram of the position of the through hole according to the embodiments of the present disclosure is shown;

[0022] Figure 7a - Figure 7i A schematic diagram of the recess of the pressing tool according to the embodiments of the present disclosure is shown;

[0023] Figure 8a - Figure 8e A working flow of the pressing tool according to the embodiments of the present disclosure is shown.

[0024] BRIEF DESCRIPTION OF DRAWINGS

[0025] 1 - object carrying platform, 11 - hollow part;

[0026] 2 - pressing tool, 2a - first pressing tool, 2b - second pressing tool, 2c - third pressing tool, 2d - fourth pressing tool, 21 - pressing tool body, 22 - recess, 23 - first surface, 24 - second surface, 25 - through hole;

[0027] 3 - stack of cores;

[0028] 41 - positive electrode sheet, 42 - negative electrode sheet, 43 - separator, 431 - separator distal end, 432 - first layer separator end, 433 - second layer separator start, 434 - second layer separator end, 44 - push plate;

[0029] 91 - left side, 92 - right side, 93 - front side, 94 - back side, 95 - top side, 96 - bottom side. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present disclosure will be described clearly and completely in combination with the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present disclosure.

[0031] It should be understood that the terms "comprise" and "include" used in the specification and claims of the present disclosure indicate the presence of the described features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0032] It should also be understood that the terms used in the specification of the present disclosure are only for the purpose of describing specific embodiments, and are not intended to limit the present disclosure. As used in the specification and claims of the present disclosure, the singular forms "a", "an" and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should be further understood that the term "and / or" used in the specification and claims of the present disclosure means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0033] As used in the specification and claims, the term "if" can be interpreted as "when" or "upon" or "in response to a determination" or "in response to detecting" depending on the context. Similarly, the phrase "if it is determined" or "if [a described condition or event] is detected" can be interpreted as meaning "upon determining" or "in response to determining" or "upon detecting [a described condition or event]" or "in response to detecting [a described condition or event]", depending on the context.

[0034] The specific embodiments of the present disclosure will be described in detail below in combination with the accompanying drawings.

[0035] With the development of battery manufacturing technology, high-performance lithium batteries have been favored by the market. Among them, the battery cell is an important part of the lithium battery, which determines the key indicators such as capacity, cycle life, safety, etc. of the lithium battery. Among them, lithium ion batteries can be divided into winding process and laminated process according to the manufacturing process of the battery cell. In general, the laminated process has been widely recognized in the market due to its high space utilization, stable internal structure, high safety and other advantages. However, compared with the winding process, the laminated process requires more equipment, high investment, and high technical requirements, and the production efficiency and yield have been restricted by the laminating machine.

[0036] The laminating machine is a production machine for laminated battery cells of lithium batteries. In the production process of lithium batteries, the laminating step mainly involves the positive electrode feeding mechanism, the negative electrode feeding mechanism, the diaphragm feeding mechanism, the laminating platform and the cell taking-out mechanism. The pre-prepared positive electrode paste and negative electrode paste are respectively extruded or sprayed onto the metal plate, and then dried, punched and other steps to finally form the positive electrode sheet and negative electrode sheet used for laminating. The positive electrode feeding mechanism, the negative electrode feeding mechanism and the diaphragm feeding mechanism respectively deliver the positive electrode sheet, the negative electrode sheet and the diaphragm to the laminating platform. The positive electrode sheet, the negative electrode sheet and the diaphragm are stacked in turn on the laminating platform, and the positive electrode sheet and the negative electrode sheet are separated by the diaphragm. Finally, the cell taking-out mechanism takes out the stacked cell.

[0037] The positive electrode sheet and the negative electrode sheet are both sheet-shaped materials, which are generally rectangular in shape and have a relatively light weight. Therefore, the positive electrode feeding mechanism and the negative electrode feeding mechanism generally use suction cup devices to suck the positive electrode sheet and the negative electrode sheet, and alternately place the positive electrode sheet and the negative electrode sheet into the laminating platform for stacking. The positive electrode feeding mechanism and the negative electrode feeding mechanism generally use a secondary positioning method, that is, the electrode sheet is first taken out from the electrode sheet storage area with relatively loose activity space, placed into the electrode sheet position adjustment area with activity space slightly larger than the size of the electrode sheet to adjust the position of the electrode sheet, and then the electrode sheet after position adjustment is sucked out and placed into the laminating platform to improve the accuracy of the electrode sheet placement position. After the positive electrode sheet or the negative electrode sheet is placed, the diaphragm feeding mechanism places continuous diaphragms into the laminating platform, so that the just-placed electrode sheet and the electrode sheet to be placed later are physically isolated by the diaphragm to prevent the positive electrode sheet from contacting the negative electrode sheet. In this way, the positive electrode sheet, the diaphragm, the negative electrode sheet and the diaphragm are placed in turn to form a "sandwich" structure of the cell monomer on the loading platform. A plurality of such "sandwich" structure cell monomers are stacked to form the cell of the battery. When the number of positive electrode sheets and negative electrode sheets reaches the preset value, the placement of the electrode sheet and the diaphragm is stopped, the diaphragm is cut off, and the cell taking-out mechanism can clamp out the battery cell. Figure 1 The structure of the lithium battery cell using the laminated process is shown.

[0038] In the process of stacking, the positive electrode sheet, the separator, and the negative electrode sheet are required to be stacked in order. Since the separators are continuous and the layers of separators are zigzag, the positive electrode sheet and the negative electrode sheet are sandwiched between two layers of separators. Therefore, during the stacking process, a special fixing device needs to be provided to prevent the electrode sheet and the separator from sliding accidentally during the stacking process, which affects the stacking effect. Usually, a pressing knife is arranged at each corner of the stacking platform to press the corner of the electrode sheet, so as to make the whole stack compact and prevent sliding.

[0039] Figure 2 The overall structure of the stacking platform according to the embodiments of the present disclosure is shown.

[0040] As shown in Figure 2 , a stacking platform for stacking electrode sheets to form a stacked core 3, the stacking platform comprises a loading platform 1 and a pressing knife 2. The loading platform 1 has a loading surface for carrying the stacked core 3. The pressing knife 2 is arranged on the side of the stacked core 3 away from the loading surface. The pressing knife 2 comprises a pressing knife body 21 and a recess 22. The pressing knife body 21 comprises a first surface 23 facing the stacked core 3. The recess 22 is formed on the first surface 23. The pressing knife 2 is arranged above the stacked core 3 and can move in a direction perpendicular to the loading platform 1 and / or in a direction parallel to the loading platform 1. When the first surface 23 of the pressing knife 2 is in contact with the stacked core 3, a hollow area is formed between the recess 22 and the stacked core 3. The first direction is perpendicular to the loading surface.

[0041] It should be noted that "above" used herein is only for convenient description, which generally refers to the direction upward perpendicular to the surface of the stacked core 3 with Figure 1 and Figure 2 as the reference. On the contrary, "below" refers to the direction downward perpendicular to the surface of the stacked core 3 with Figure 1 and Figure 2 as the reference. Specifically, the shape of the loading surface of the loading platform 1 is not limited, which can be rectangular, trapezoidal, or other shapes. The included angle between the two sides of the stacking can be a right angle or a rounded angle. The upper surface of the loading platform 1 is flat, and the middle part of the upper surface of the loading platform 1 is used for stacking and placing the stacked core 3. The upper surface of the loading platform 1 is the loading surface. The loading platform 1 is arranged horizontally, so that the stacked core 3 placed on the loading platform 1 is in a stable state, preventing the layers of the stacked core 3 from being parallel due to the inclination of the loading platform 1.

[0042] The stacked core 3 can be a stack of electrode sheets and separators for manufacturing battery cells, which has a horizontal hierarchical structure. The shape and size of the horizontal cross section of the electrode sheet and the separator correspond, but are not limited to specific shapes and sizes. The shape is preferably rectangular. During the stacking process, the height of the stacked core 3 increases continuously as new electrode sheets and separators are added.

[0043] Figure 3 A schematic diagram of the pressure knife structure according to an embodiment of this disclosure is shown. Figure 3 As shown, the pressure knife 2 is elongated in shape, and its material is not limited; it can be made of metal or plastic. The pressure knife 2 is mounted on the loading platform 1, and its horizontal height is higher than the upper surface of the stacked core 3. One end of the pressure knife 2 closest to the stacked core 3 can contact and press against the stacked core 3 to prevent slippage between the layers inside the stacked core 3. In the pressure knife 2, the first surface 23 is the lower surface of the pressure knife 2, i.e., the surface in contact with the stacked core 3; the second surface 24 is the upper surface of the pressure knife 2, and this plane can be parallel to or not parallel to the first surface 23. The shape of the horizontal cross-section of the pressure knife 2 is not limited and can be as follows: Figure 2 The rectangle shown can be a trapezoid, a rounded rectangle, a rounded trapezoid, or an irregular shape. The overall shape of the vertical cross-section of the pressure knife 2 is also unrestricted and can be, for example... Figure 2 The rectangle shown.

[0044] The pressure knife 2 primarily performs clamping and lifting operations to fix and release the stacked core 3. During the clamping operation, the pressure knife 2 moves downwards in a direction perpendicular to the upper surface of the carrying platform 1 until its first surface 23 directly contacts and clamps the upper surface of the stacked core 3. At this point, a hollow area is formed between the recess 22 of the pressure knife 2 and the stacked core 3. The presence of this hollow area reduces the contact area between the pressure knife 2 and the more vulnerable parts of the stacked core 3, thereby reducing the pressure exerted by the pressure knife 2 on the stacked core 3 and lowering the possibility of the vulnerable parts of the stacked core 3 cracking or shedding powder due to pressure. Accordingly, when the lifting operation is performed, the pressure knife 2 moves in a direction perpendicular to the upper surface of the carrying platform 1 until the first surface 23 of the pressure knife 2 is no longer in contact with the upper surface of the stack core 3. Then, it continues to move in a direction perpendicular to the upper surface of the carrying platform 1, so that sufficient space is created between the first surface 23 of the pressure knife 2 and the upper surface of the stack core 3, allowing the electrodes and separators to be stacked to continue to be stacked onto the stack core 3 without obstruction, thereby continuing the stacking process. In addition, during the pressing and lifting operations, the pressure knife 2 can move in the horizontal direction. For example, when the pressure knife 2 is lifted, it also moves in the horizontal direction, causing the end of the pressure knife 2 near the stack core 3 to move away from the stack core 3 in the horizontal direction, allowing the pressure knife 2 to avoid the electrodes being stacked, and creating more space between the first surface 23 of the pressure knife 2 and the upper surface of the stack core 3, making it easier for the electrodes and separators to be stacked to continue to be stacked onto the stack core 3.

[0045] like Figure 2As shown, four pressing knives 2 can be provided on the loading platform 1, but it should be understood that the number of pressing knives is not limited and can be any other desired number. In addition, for the convenience of description, the four pressing knives 2 are denoted as first pressing knife 2a, second pressing knife 2b, third pressing knife 2c and fourth pressing knife 2d respectively.

[0046] The four pressing knives 2a-2d are arranged at the four corners of the horizontal cross section of the loading platform 1. Specifically, the first pressing knife 2a is arranged at the left rear corner of the horizontal cross section of the loading platform 1, the second pressing knife 2b is arranged at the right rear corner of the horizontal cross section of the loading platform 1, the third pressing knife 2c is arranged at the left front corner of the horizontal cross section of the loading platform 1, and the fourth pressing knife 2d is arranged at the right front corner of the horizontal cross section of the loading platform 1. Among them, the left direction refers to the direction shown in Figure 2 , the right direction refers to the direction shown in Figure 2 , the front direction refers to the direction shown in Figure 2 , the rear direction refers to the direction shown in Figure 2 , the upper direction refers to the direction shown in Figure 2 , and the lower direction refers to the direction shown in Figure 8a . The horizontal height of the first pressing knife 2a, the second pressing knife 2b, the third pressing knife 2c and the fourth pressing knife 2d is higher than the upper surface of the loading platform 1, so that when the first pressing knife 2a, the second pressing knife 2b, the third pressing knife 2c and the fourth pressing knife 2d perform the pressing operation respectively, the four pressing knives 2a-2d can form a clamping structure with the upper surface of the loading platform 1 respectively, and at the same time, the pressure is applied to the upper and lower surfaces of the core 3, so that each layer of the core 3 can be kept stationary and prevent accidental sliding.

[0047] Figure 8e - Figure 8a The working process of the pressing knife of the embodiment of the present disclosure is shown.

[0048] As Figure 8b shown, in the current state, the first pressing knife 2a and the second pressing knife 2b are located on the left side of the loading platform 1 and are in the pressing state, and the lower surfaces thereof are in close contact with the upper surface of the negative plate 42 which is currently the highest; the third pressing knife 2c and the fourth pressing knife 2d are located on the right side of the loading platform 1 and are in the pressing state, and the lower surfaces thereof are in close contact with the upper surface of the positive plate which is currently the second highest, and the upper surfaces thereof are in close contact with the lower surface of the separator 43. The separator distal end 431 is the end of the separator 43 which is closer to the outlet of the separator supply mechanism, and at this time, the separator distal end 431 is located above the left side of the loading platform 1. Among the stacked separators, the layer with the highest horizontal height is the separator below the negative plate 42, and the end close to the separator distal end 431 is the first layer separator termination end 432. At this time, since the separator distal end 431 and the first layer separator termination end 432 are both located on the left side of the loading platform 1, it is not possible to continue stacking the separator on the loading platform 1.

[0049] Then as Figure 8c As shown, in order to continue stacking diaphragms onto the platform 1, the diaphragm feeding mechanism is horizontally transferred from the left side of the platform 1 to the right side, thereby transferring the distal end 431 of the diaphragm from the upper left side of the platform 1 to the upper right side. At this time, since the termination end 432 and the distal end 431 of the first layer of diaphragm 43 are on opposite sides of the platform 1, the diaphragm between the termination end 432 and the distal end 431 is inclined, and this diaphragm contacts the left side of the negative electrode 42, with the contact point being the beginning end 433 of the second layer of diaphragm. This contact point divides the diaphragm between the termination end 432 and the distal end 431 of the first layer of diaphragm into two parts. The diaphragm between the termination end 432 and the beginning end 433 of the second layer of diaphragm is parallel and closely attached to the left side of the negative electrode 42, while the diaphragm between the beginning end 433 and the distal end 431 of the second layer of diaphragm remains inclined.

[0050] After the distal end 431 of the separator is horizontally transferred from the left side to the right side of the platform 1, the pusher plate 44, which is directly above the stack, begins to move downward perpendicularly to the platform 1. The bottom surface of the pusher plate 44 adsorbs the positive electrode 41, making the positive electrode 41 parallel to the platform 1. As the pusher plate 44 pushes, the positive electrode 41 begins to move downward. At this time, since the starting end 433 and the distal end 431 of the second layer separator 43 are on opposite sides of the platform 1, the separator between the starting end 433 and the distal end 431 is tilted, and this separator will contact the right side of the positive electrode 41, with the contact point being the termination end 434 of the second layer separator. This contact point divides the membrane between the starting end 433 and the distal end 431 of the second membrane into two parts. The membrane between the terminating end 434 and the distal end 431 of the second membrane is parallel and closely attached to the right side of the positive electrode plate 41, while the membrane between the starting end 433 and the terminating end 434 of the second membrane is still inclined.

[0051] As the pusher plate 44 moves downwards, the positive electrode plate 41 also moves downwards. Therefore, the termination end 434 of the second separator gradually moves away from the distal end 431 and gradually approaches the beginning end 433. The separator between the beginning end 433 and the termination end 434 gradually changes from an inclined state to parallel with the platform 1, and the length of the separator between the beginning end 433 and the distal end 431 continuously increases. Then... Figure 8dAs shown, finally, the positive electrode sheet 41 pushed by the push plate 44 is tightly attached to the separator between the second layer separator start end 433 and the second layer separator end end 434, and the separator between the positive electrode sheet 41, the second layer separator start end 433 and the second layer separator end end 434, and the negative electrode sheet 42 are parallel to each other.

[0052] Finally, as shown in FIG. 6, the push plate 44 is fixed to the positive electrode sheet 41, and the push plate 44 is moved upward to separate the positive electrode sheet 41 from the stack of the core 3. At this time, the third pressing knife 2c and the fourth pressing knife 2d on the right side of the object platform 1 are extracted from the stack, and the lifting operation is performed to raise the horizontal height of the third pressing knife 2c and the fourth pressing knife 2d to be higher than the upper surface of the positive electrode sheet 41. Then, the pressing operation is performed to attach to the upper surface of the positive electrode sheet 41, so that the third pressing knife 2c and the fourth pressing knife 2d press the current uppermost positive electrode sheet 41 downward. Figure 8e

[0053] Figure 4 The position relationship between the pressing knife 2 and the electrode sheet is shown, the upper object is the pressing knife 2, and the lower object is the positive electrode sheet 41 or the negative electrode sheet 42, wherein the concave part 22 of the pressing knife 2 is aligned with the edge of the electrode sheet.

[0054] Figure 4 The structure schematic diagram of the object platform and the pressing knife of the embodiment of the present disclosure is shown.

[0055] As shown in FIG. 5, in some embodiments, the object platform 1 is provided with a hollow part 11 recessed in the first direction on the object surface of the object platform 1, and the projection part of the core 3 in the first direction covers the hollow part 11. The hollow part 11 can be recessed downward from the upper surface of the object platform 1, so as to be located below the position of the stack of the core 3. Through the hollow part 11, the finished battery core can be conveniently taken out from the object platform 1 after the stack is completed, and heat dissipation and cleaning can be facilitated. Figure 5a

[0056] Figure 5d The structure schematic diagram of the object platform of the embodiment of the present disclosure is shown. As shown in FIG. 6, the hollow part 11 is recessed in the first direction on the object surface of the object platform 1, and the projection part of the core 3 in the first direction covers the hollow part 11. Figure 5a Figure 5d Figure 5a As shown in FIG. 5 and FIG. 6, the horizontal cross-sectional shape of the hollow part 11 is not limited, and can be composed of a single figure, including but not limited to a rectangle (such as Figure 5b ), a round head rectangle (such as Figure 5c ), a round corner rectangle, a trapezoid (such as Figure 5d ), etc.; or can be composed of multiple figures not connected to each other, such as composed of two rectangles not connected to each other, such as Figure 6 .

[0057] ​​​​The hollow part 11 is preferably a notch formed on the object platform, so that when the stack is completed, the battery cell taking-out mechanism can be used to take out the completed battery cell on the object platform 1. The battery cell taking-out mechanism can include a horizontally movable clamping assembly. The clamping assembly can have one set of upper or lower ends, or multiple sets of upper or lower ends, which cooperate with each other to stably clamp the object, especially to prevent the internal layers of the clamped object from slipping. The upper and lower ends of the clamping assembly can be provided with devices for increasing static friction, such as anti-slip rubber patches. The lower end of the clamping assembly extends into the hollow part 11 directly below the object platform 1, and the upper end extends to the top of the stack of cells 3, with a height higher than the upper surface of the stack of cells 3. Then the upper end moves downward, tightly clamping the stack of cells 3 with the upper and lower ends, preventing displacement of the individual layers within the stack of cells 3, and transferring the stack of cells 3 from the object platform 1 to another location by clamping, to complete other steps.

[0058] Figure 6 A schematic diagram of the position of the through hole is shown.

[0059] As Figure 7a shown, in some embodiments, the stack platform further comprises a driving assembly (not shown in the figure), the pressing knife body 21 comprises at least one through hole 25, the through hole 25 is provided with threads, and the pressing knife body 21 is connected with the driving assembly through the through hole 25. The driving assembly moves the pressing knife body 21 in the first direction.

[0060] Specifically, the pressing knife body 21 is provided with a through hole 25 away from one end of the stack of cells 3. The number of through holes 25 can be one or multiple, preferably four. When the number of through holes 25 is four, the four through holes can be arranged in a rectangular shape. The through hole 25 is connected with the driving assembly through a fastener, so that the pressing knife body 21 is driven by the driving assembly to perform the operation of pressing down or lifting up. The through hole 25 is provided with threads, so that a bolt with a corresponding hole diameter can be used to fix the pressing knife body 21 and the driving assembly. By providing the through hole 25 on the pressing knife body 21 and connecting the through hole 25 with the driving assembly through a fastener, it is ensured that the pressing knife 2 and the driving assembly can be tightly connected, preventing the pressing knife 2 and the driving assembly from loosening, which in turn causes the first surface 23 of the pressing knife 2 to fail to directly contact the upper surface of the stack of cells 3 when performing the operation of pressing the stack of cells 3, or even if it can directly contact, it cannot apply enough pressure to the upper surface of the stack of cells 3, causing displacement of the individual layers within the stack of cells 3 and affecting the precision of the stack.

[0061] The driving assembly is used to generate driving force for the pressing knife 2, which can be an electric motor. The four driving assemblies can work independently of each other, so that the four corresponding pressing knife bodies 21 perform different actions respectively, or can work together, so that the four corresponding pressing knife bodies 21 complete the same action at the same time. In addition, the driving assembly can provide sufficient pressure so that the pressing knife body 21 can press the core 3 tightly to prevent the layers inside the core 3 from sliding, thereby affecting the accuracy of the stacking.

[0062] When performing the operation of pressing the core 3, the pressing knife body 21 is driven by the driving assembly and moves in a direction perpendicular to the downward direction of the loading platform 1 until the first surface 23 of the pressing knife 2 is in direct contact with the upper surface of the core 3 and the core 3 is pressed tightly, and a hollow area is formed between the recess 22 of the pressing knife 2 and the core 3. When performing the lifting operation, the pressing knife body 21 is driven by the driving assembly and moves in a direction perpendicular to the upward direction of the loading platform 1 by a distance, so that the first surface 23 of the pressing knife 2 is no longer in close contact with the upper surface of the core 3, and a sufficient space is formed between the first surface 23 of the pressing knife 2 and the upper surface of the core 3, and under the action of the positive electrode feeding mechanism, the negative electrode feeding mechanism or the diaphragm feeding mechanism, the electrode sheet to be stacked, the diaphragm can be stacked on the core 3 without being blocked, thereby continuing the process of stacking.

[0063] Figure 7i - Figure 7a The recess of the pressing knife of the embodiment of the disclosure is shown in the schematic diagram, and the recess 22 is the gray area in the figure.

[0064] As Figure 7i - Figure 7a shown, in some embodiments, the recess 22 is arranged in the edge region or the internal region of the pressing knife body 21.

[0065] Specifically, the position of the recess 22 of the pressing knife body 21 has multiple choices. For example, the recess 22 can be located in the edge region of the pressing knife body 21, that is, the edge of the recess 22 coincides with the edge of the first surface 23 of the pressing knife body 21; or can be located in the internal region of the first surface 23, that is, the edges of the recess 22 are all located in the internal region of the first surface 23 of the pressing knife body 21. When the recess 22 is located in the edge region of the pressing knife body 21, since the edge region of the pressing knife body 21 is relatively close to the edge of the core 3, therefore, in this case, only a small part or no part of the edge of the core 3 is in contact with the pressing knife body 21, so that the possibility of cracking or powder falling of the edge of the core 3 is reduced during the pressing operation.

[0066] In some embodiments, the pressing tool body 21 further comprises a second surface 24 facing away from the stack core 3, the recess 22 is recessed from the first surface 23 to the second surface 24, and the recess 22 has a concave surface. In some embodiments, the concave surface is an arc surface or a plane.

[0067] By designing the recess 22, the pressing tool body 21 can reduce the amount of material used in the manufacturing process, reduce the manufacturing difficulty of the pressing tool, and thus reduce the cost.

[0068] In some embodiments, the pressing tool body 21 further comprises a side surface connecting the first surface 23 and the second surface 24, the recess 22 is formed along the edge of the first surface 23, and the recess 22 communicates the first surface 23 and the side surface, so that the concave surface forms a stepped surface.

[0069] Specifically, the recess 22 is formed along the edge of the first surface 23 of the pressing tool body 21. Here, the edge of the first surface 23 refers to the area of the first surface 23 of the pressing tool 2 close to the edge of the stack core 3. After the first surface 23 of the pressing tool 2 directly contacts and compresses the upper surface of the stack core 3, the hollow area formed between the recess 22 and the stack core 3 is directly connected to the outside world. Due to the existence of the hollow area, the contact area between the pressing tool 2 and the edge part of the stack core 3 is reduced, thereby reducing the possibility of cracks or powder falling off the edge of the stack core 3 caused by the extrusion of the pressing tool 2. At the same time, compared with the prior art mentioned in the background art, in the technical solution disclosed in the present disclosure, the pressing tool 2 will not produce relative displacement in the horizontal direction relative to the stack core 3 when it contacts the stack core 3. Therefore, the pole piece and the separator will not be damaged due to the friction caused by the displacement, thereby affecting the quality of the entire battery. In addition, the recess 22 communicates the first surface 23 and the side surface, so that the concave surface forms a stepped surface, making the entire recess 22 neat in appearance and facilitating the processing of the pressing tool 2.

[0070] As shown in Figure 7i Figure 7a In some embodiments, the projection part of the recess 22 in the first direction is formed in a straight line shape, a concave shape, or an L shape.

[0071] Specifically, the horizontal cross section of the recess 22 can be a straight line shape, a concave shape, or an L shape, and each of the above shapes has its corresponding beneficial effect.

[0072] When the horizontal cross section of the recess 22 is a straight line shape, as shown in Figure 7b The long side of the straight line shaped recess 22 is parallel to the long side of the pressing tool 2, and the long side of the straight line shaped recess 22 is located at the edge of the pressing tool 2. As shown in Figure 7c ​As shown, the long side of the inline recess 22 is parallel to the short side of the pressure knife 2, and the long side of the inline recess 22 is located at the edge of the pressure knife 2. Figure 7e As shown, the long side of the straight recess 22 is parallel to the short side of the pressing knife 2, but the long side of the straight recess 22 is not located at the edge of the pressing knife 2. A pressing knife 2 with a straight recess 22 can be used when the more fragile part of the electrode or diaphragm is located at the edge, or when it is not at the edge but forms a straight line overall. Since the hollow area formed between the recess 22 of the pressing knife 2 and the stacked core 3 is straight, the area where the pressing knife 2 does not contact the stacked core 3 is also straight. In this case, if the area where the pressing knife 2 does not contact the stacked core 3 happens to be located in a more fragile area of ​​the electrode in the stacked core 3, the possibility of cracks or powder shedding can be reduced because the pressing knife 2 has less or no contact with the more fragile area on the upper surface of the stacked core 3.

[0073] When the horizontal cross-section of the concave portion 22 is L-shaped, such as Figure 7f As shown, at this time, the turning angle of the L-shaped recess 22 is one of the corners of the pressure knife 2 near the stacked core 3. Figure 7e and Figure 7f Similar, the difference is, Figure 7g The concave portion 22 extends through the short side of the pressing knife 2. When the more vulnerable parts of the electrode or diaphragm are located at the four corners, an L-shaped pressing knife 2 with a concave portion 22 can be used. Since the hollow area formed between the concave portion 22 of the pressing knife 2 and the stacked core 3 is L-shaped, the area where the pressing knife 2 does not contact the stacked core 3 is also L-shaped. In this case, if the area where the pressing knife 2 does not contact the stacked core 3 happens to be located at a more vulnerable corner on the electrode in the stacked core 3, the possibility of cracks or powder shedding can be reduced because the pressing knife 2 has less or no contact with the more vulnerable area on the upper surface of the stacked core 3.

[0074] When the horizontal cross-section of the concave part 22 is concave, such as Figure 7e As shown, at this time, the two turning angles of the concave portion 22 are the two included angles of the pressure knife 2 near the end of the stacked core 3. Relative to Figure 7f , Figure 7d The advantage of the pressure knife 2 shown is that, since the two corners of the pressure knife 2 near one end of the stacked core 3 do not contact each other, the installation of only this type of U-shaped recess 22 pressure knife 2 is sufficient to protect the more fragile edges or corners of the electrode sheets in the stacked core 3.

[0075] Furthermore, these shapes can be either right angles or rounded corners. Additionally, the recess 22 can be formed by combining and assembling multiple shapes, such as... ​ As shown. Due to the different positions of the recess 22 on the pressure knife body 21, the hollow area formed between the recess 22 of the pressure knife 2 and the stacked core 3 is also different. Therefore, the area where the pressure knife 2 and the stacked core 3 do not contact each other is also different.

[0076] The user only needs to select the presser foot 2 containing the appropriate recess 22 according to the position of the relatively fragile area on the upper surface of the core 3, in the case of only replacing different presser feet 2, including using the same presser foot 2 and different presser feet 2, so that the presser foot 2 has less contact or no contact with the relatively fragile area of the surface, thereby reducing the possibility of cracks or powder falling in different areas of the core 3, and having certain expandability.

[0077] In some embodiments, the recess 22 extends through the presser foot body 21 in the first direction.

[0078] Specifically, the recess 22 can extend through the presser foot body 21 in the first direction, so that the second surface 24 of the presser foot 2 is hollow. At this time, the first surface 23 and the second surface 24 are penetrated by the recess 22, so that heat dissipation can be more convenient.

[0079] The disclosure also discloses a laminating machine, wherein the laminating machine is provided with a laminating platform as described in any one of the disclosure.

[0080] The laminating machine is an important equipment for square lithium battery production, which is used for manufacturing lithium battery cells. The laminating machine generally consists of ten parts, which are: a feeding mechanism, a positive electrode material box, a negative electrode material box, a positive electrode secondary positioning mechanism, a negative electrode secondary positioning mechanism, a positive electrode feeding mechanism, a negative electrode feeding mechanism, a laminating platform, a rubberizing mechanism and a discharging mechanism. The working principle is that the positive and negative electrode sheets are loaded into the material box, the mechanical hand moves left and right, and the electrode sheets are sucked in the positive and negative material boxes, and after secondary positioning, the positive and negative electrode sheets are alternately placed on the laminating table. The separator is actively unwound, and the laminating platform drives the separator to move left and right to form a Z-shaped winding; after the laminating is completed, it is cut off according to the set length, and automatically sent to the manual rubberizing.

[0081] Specifically, the laminating platform uses the laminating platform described in the disclosure, and the other parts are not limited. As described above, the laminating platform includes a carrier platform and a presser foot, wherein the carrier platform is used to carry the core; the presser foot includes a presser foot body and a recess, the presser foot body includes a first surface facing the core, and the recess is formed on the first surface; the presser foot is arranged above the core and can move in a direction perpendicular to the carrier platform, and when the first surface of the presser foot contacts the core, a hollow area is formed between the recess and the core.

[0082] The laminating platform can also form a hollow part on the carrier platform, and the hollow part is formed in the area where the carrier platform and the presser foot body do not contact.

[0083] In addition, the lamination platform can further comprise a driving assembly, the pressing knife body comprises at least one through hole, and a thread is arranged in the through hole to be matched and connected with the driving assembly, so as to fix the pressing knife body and make the pressing knife body move in a direction perpendicular to the object platform.

[0084] Compared with the traditional lamination platform, by using the lamination platform disclosed in the present disclosure, the edge cracks and powder falling of the pole piece during the pressing process can be prevented, the stacked battery cell can be conveniently taken out from the object platform, the heat dissipation effect of the object platform can be improved, and the cleaning of the object platform is facilitated.

[0085] Although the embodiments of the present disclosure have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Many modifications, changes and substitutions can be made by those skilled in the art without departing from the idea and spirit of the present disclosure. It should be understood that various alternatives to the embodiments of the present disclosure described herein can be employed in practicing the present disclosure. The appended claims are intended to define the scope of protection of the present disclosure and thus cover equivalents or alternatives within the scope of these claims.

Claims

1. A lamination stage for laminating pole pieces to form a core, characterized by, The lamination platform comprises a carrier platform (1) and a pressing knife (2), wherein, The carrier platform (1) has a carrier surface for carrying the lamination core (3); The pressing knife (2) is arranged on the side of the lamination core (3) away from the carrier surface, and the pressing knife (2) comprises a pressing knife body (21) and a recess (22), the pressing knife body (21) comprises a first surface (23) facing the lamination core (3), and the recess (22) is formed on the first surface (23); The pressing knife (2) can move in a first direction, and when the first surface (23) of the pressing knife (2) is in contact with the lamination core (3), a hollow area is formed between the recess (22) and the lamination core (3), and the first direction is perpendicular to the carrier surface.

2. The lamination platform of claim 1, wherein, The carrier surface of the carrier platform (1) is recessed in the first direction to form a hollow part (11), and the projection of the lamination core (3) in the first direction covers the hollow part (11).

3. The lamination platform of claim 1, wherein, The lamination platform further comprises a driving assembly, the pressing knife body (21) comprises at least one through hole (25) provided with a thread, and the pressing knife body (21) is connected with the driving assembly through the through hole (25), so that the driving assembly drives the pressing knife body (21) to move in the first direction.

4. The lamination platform of claim 1, wherein, The recess (22) is arranged in an edge region or an internal region of the pressing knife body (21).

5. The lamination platform of claim 1, wherein, The pressing knife body (21) further comprises a second surface (24) away from the lamination core (3), the recess (22) is recessed from the first surface (23) to the second surface (24), and the recess (22) has a concave surface.

6. The lamination station of claim 5, wherein, The concave surface is an arc surface or a plane.

7. The lamination station of claim 5, wherein, The pressing knife body (21) further comprises a side surface connecting the first surface (23) and the second surface (24), the recess (22) is formed along the edge of the first surface (23), and the recess (22) is connected with the first surface (23) and the side surface, so that the concave surface forms a stepped surface.

8. The lamination station of claim 7, wherein, The projection of the recess (22) in the first direction is formed in a straight line, a concave shape or an L shape.

9. The lamination station of claim 1, wherein, The recess (22) penetrates the pressing knife body (21) in the first direction.

10. A lamination machine characterized by, The lamination machine is provided with the lamination platform as claimed in any one of claims 1-9.

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