Cell lamination device

Abstract

The utility model belongs to the technical field of battery cell manufacturing, and discloses a battery cell lamination device which comprises a lamination table and a pressing knife assembly, the pressing knife assembly comprises a mounting seat and a pressing knife main body, one end of the pressing knife main body is connected with the mounting seat, and one end, far away from the mounting seat, of the pressing knife main body comprises a first pressing part and a second pressing part; the first pressing part and the second pressing part are both round corners, the radius of the first pressing part is larger than that of the second pressing part, and the large round corner requirement of the first pressing part and the small round corner requirement of the second pressing part can be met at the same time. The first pressing part is used for pressing the non-edge area of the pole piece, and the stress at the corresponding position on the pole piece can be reduced through the arrangement of the large round corner of the first pressing part, so that indentation and tearing of the pole piece are avoided; the second pressing part is used for pressing the edge area of the pole piece, and the small round corner of the second pressing part is arranged, so that the influence on the edge of the pole piece when the diaphragm is folded can be reduced, and the conditions of indentation, tearing or material falling on the edge of the pole piece are avoided.

Description

Cell stacking device Technical Field

[0001] This utility model relates to the field of battery cell manufacturing technology, and in particular to a battery cell stacking device. Background Technology

[0002] The battery cell is the core component of a battery. It is manufactured using a lamination technique, which involves using a separator to separate the positive and negative electrode plates and stacking them sequentially to form a cell. Z-type lamination is a relatively important lamination method in lithium batteries. Its basic principle and working process are as follows: a winding mechanism releases the separator wound on it; the reciprocating movement of the lamination stage folds the separator into a Z-shape; simultaneously, a robotic arm alternately places the positive and negative electrode plates between the folded separator, separating them; this process is repeated multiple times to ultimately form a lithium battery cell of a certain thickness.

[0003] To improve the stability of the battery cells during the stacking process, a pressure knife is also installed. This pressure knife holds the semi-finished battery cells folded on the stacking table in place, preventing them from unraveling due to lack of fixing force and preventing displacement of the separator and positive / negative electrode sheets, thus ensuring the reliability of the stacking. In related technologies, when the pressure knife presses firmly onto the electrode sheets of the battery cell, stress concentration at the corners of the pressure knife can easily cause indentations or even tearing of the electrode sheets. Summary of the Invention

[0004] The purpose of this invention is to provide a battery cell stacking device to solve the problems in related technologies.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] The cell stacking device includes:

[0007] Stacking table;

[0008] The pressing knife assembly includes a mounting base and a pressing knife body. One end of the pressing knife body is connected to the mounting base, and the other end extends above the stacking table. The end of the pressing knife body away from the mounting base includes a first pressing part and a second pressing part. The second pressing part is located on the side close to the edge of the stacking table. Both the first pressing part and the second pressing part have rounded corners, and the radius of the first pressing part is larger than the radius of the second pressing part.

[0009] The beneficial effects of this utility model are:

[0010] The battery cell stacking device provided by this utility model can simultaneously meet the large rounded corner requirements of the first pressing part and the small rounded corner requirements of the second pressing part by setting the radius of the first pressing part to be larger than that of the second pressing part. The first pressing part is used to press on the non-edge area of ​​the electrode sheet. By setting the large rounded corner of the first pressing part, the stress at the corresponding position on the electrode sheet can be reduced, thereby avoiding indentation and tearing of the electrode sheet. The second pressing part is used to press on the edge area of ​​the electrode sheet. By setting the small rounded corner of the second pressing part, the impact of the separator folding on the edge of the electrode sheet can be reduced, avoiding indentation, tearing or material loss at the edge of the electrode sheet. Attached Figure Description

[0011] Figure 1 is a schematic diagram of the structure of the cell stacking device provided in an embodiment of the present invention;

[0012] Figure 2 is a schematic diagram of the structure of the pressure knife assembly involved in the embodiment of this utility model;

[0013] Figure 3 is a schematic diagram of the structure of the pressing knife assembly in the embodiment of this utility model when it is pressed against the electrode sheet;

[0014] Figure 4 is a magnified view of part B in Figure 3;

[0015] Figure 5 is a cross-sectional schematic diagram of the pressure knife body involved in the embodiment of this utility model.

[0016] In the picture:

[0017] 1. Electrode; 2. Diaphragm;

[0018] 10. Stacking table; 20. Pressure knife assembly; 21. Mounting base; 22. Pressure knife body; 221. First side; 222. Second side; 2221. First clamping part; 2222. Second clamping part; 223. Hole. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0020] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0021] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0022] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0023] As shown in Figures 1 to 5, this embodiment of the present invention provides a battery cell stacking device, including a stacking platform 10 and a pressing knife assembly 20. The pressing knife assembly 20 includes a mounting base 21 and a pressing knife body 22. One end of the pressing knife body 22 is connected to the mounting base 21, and the other end extends above the stacking platform 10. The end of the pressing knife body 22 away from the mounting base 21 includes a first pressing part 2221 and a second pressing part 2222. The second pressing part 2222 is located on the side of the first pressing part 2221 near the edge of the stacking platform 10. Both the first pressing part 2221 and the second pressing part 2222 have rounded corners, and the radius of the first pressing part 2221 is larger than the radius of the second pressing part 2222. When the battery cell is stacked, the positive electrode 1 and the negative electrode 1 are stacked sequentially on the stacking platform 10, and a separator 2 is stacked between the positive electrode 1 and the negative electrode 1 for isolation. Referring to Figures 3 and 4, the pressing assembly 20 is used to press the electrode sheets 1 already stacked on the stacking table 10. The first pressing part 2221 is used to press the electrode sheet 1 in the non-edge area. The smaller the radius of the rounded corner of the first pressing part 2221, the more concentrated the stress, and the greater the stress on the corresponding position on the electrode sheet 1, which can easily lead to indentations or even tearing on the electrode sheet 1. Therefore, the first pressing part 2221 needs to have a large rounded corner. The second pressing part 2222 is used to press the electrode sheet 1 in the edge area, and at least part of the second pressing part 2222 extends beyond the edge area. The edge of the electrode 1 is used to press against the diaphragm 2. Therefore, the smaller the radius of the rounded corner of the second pressing part 2222, the smaller the area where the edge of the electrode 1 is not pressed. Area A shown in Figures 3 and 4 is the area where the edge of the electrode 1 is not pressed. Since the diaphragm 2 easily causes the edge of the electrode 1 to curl upward when folded, the smaller the area where the edge of the electrode 1 is not pressed, the less impact the diaphragm 2 has on the edge of the electrode 1 when folded, and the less likely the edge of the electrode 1 will have indentations, tears, or material loss. Therefore, the second pressing part 2222 needs to use a small rounded corner. By setting the radius of the first pressing part 2221 to be larger than the radius of the second pressing part 2222, the large rounded corner requirement of the first pressing part 2221 and the small rounded corner requirement of the second pressing part 2222 can be met.

[0024] In this embodiment, the radius of the first pressing part 2221 ranges from 6mm to 12mm. Optionally, the radius of the first pressing part 2221 can be 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, or 12mm. If the radius of the first pressing part 2221 is too small, the stress on the electrode 1 corresponding to the first pressing part 2221 will be too high, which will easily cause indentations or tears. If the radius of the first pressing part 2221 is too large, the area of ​​the side of the pressing knife body 22 pressing against the electrode 1 will be too small, and the stress on the electrode 1 will increase, which will also easily cause indentations or tears. Therefore, by setting the radius of the first pressing part 2221 in the range of 6mm-12mm, it is neither too large nor too small, which can effectively prevent indentations or tears from appearing on the electrode 1.

[0025] In this embodiment, the radius of the second pressing part 2222 ranges from 1mm to 4mm. Optionally, the radius of the second pressing part 2222 can be 1mm, 2mm, 3mm, or 4mm. If the radius of the second pressing part 2222 is too small, it is easy to tear the diaphragm 2 when folding. If the radius of the second pressing part 2222 is too large, the area of ​​the edge of the electrode 1 that is not pressed is too large, and the folding of the diaphragm 2 has a greater impact on the edge of the electrode 1. The edge of the electrode 1 is prone to indentation, tearing, or material loss. Therefore, by setting the radius of the second pressing part 2222 in the range of 1mm-4mm, which is neither too large nor too small, it is possible to effectively avoid tearing the diaphragm 2 and indentation, tearing, or material loss of the electrode 1.

[0026] In this embodiment, the distance between the outer edge of the pressing body 22 and the edge of the stacking table 10 is L, and L ranges from 2mm to 4mm. If L is too large, the outer edge of the pressing body 22 will press on the electrode 1, causing stress concentration on the electrode 1 at the position corresponding to the outer edge of the pressing body 22. If L is too small, the distance between the outer edge of the pressing body 22 and the folded part of the diaphragm 2 will be too close, easily damaging the diaphragm 2. Therefore, by setting L in the range of 2mm-4mm, it is neither too large nor too small, effectively avoiding stress concentration on the electrode 1 and damage to the diaphragm 2. In this embodiment, the outer edge of the pressing body 22 extends beyond the edge of the electrode 1 by 0.5mm-3.5mm. Preferably, the distance between the outer edge of the pressing body 22 and the edge of the electrode 1 is 1.2mm-2.8mm, or 0.7mm-3.3mm. It should be noted that the outer edge of the pressing body 22 refers to the side of the pressing body 22 that is close to the edge of the stacking table 10 along its width direction (in the direction of the arrow in Figure 3); L is the distance between the outer edge of the pressing body 22 and the edge of the stacking table 10 along its width direction (in the direction of the arrow in Figure 3).

[0027] In this embodiment, referring to FIG5, the pressure knife body 22 includes a first surface 221 and a second surface 222. The second surface 222 is located on the side near the stacking table 10. The first surface 221 and the second surface 222 are arranged opposite to each other along the thickness direction of the pressure knife body 22, and the area of ​​the second surface 222 is larger than the area of ​​the first surface 221. This arrangement can improve the structural strength of the pressure knife body 22 and reduce material costs. At the same time, the thinning of the edge of the pressure knife body 22 can avoid interference between the pressure knife body 22 and the moving diaphragm 2 when the pressure knife body 22 performs the clamping action. In this embodiment, the first clamping part 2221 and the second clamping part 2222 are both located on the second surface 222. Optionally, the cross-section of the pressure knife body 22 is an isosceles trapezoid. Alternatively, the cross-section of the pressure knife body 22 can also be a right trapezoid.

[0028] In this embodiment, referring to Figures 2 and 3, the pressure knife body 22 is provided with a through hole 223 along the thickness direction. The camera can take pictures of the electrode 1 and the diaphragm 2 through the hole 223 to detect whether the relative position and size of the electrode 1 and the diaphragm 2 meet the standards.

[0029] In this embodiment, referring to FIG1, two pressure-blade assembly units are symmetrically distributed on both sides of the stacking stage 10. Each pressure-blade assembly unit includes two spaced-apart pressure-blade assemblies 20, that is, there are a total of four pressure-blade assemblies 20. By pressing the electrode 1 simultaneously with the four pressure-blade assemblies 20, the stability of the electrode 1 can be improved.

[0030] Furthermore, the cell stacking device provided in this embodiment also includes a lifting mechanism. One end of the lifting mechanism is mounted on the base, and the other end is connected to the mounting base 21 of the pressing assembly 20. The lifting mechanism is used to drive the pressing assembly 20 to move up and down. When the pressing assembly 20 needs to fix the electrode 1 on the stacking table 10, the lifting mechanism drives the pressing assembly 20 to descend. When the electrode 1 is being placed on the stacking table 10, the lifting mechanism drives the pressing assembly 20 to rise, so as to avoid the electrode 1 that is about to be placed on the stacking table 10.

[0031] Furthermore, the cell stacking device provided in this embodiment also includes a horizontal drive mechanism, which is connected to the base and is used to drive the lifting mechanism to move closer to or further away from the stacking table 10. By setting the horizontal drive mechanism, the position of the pressing knife assembly 20 relative to the stacking table 10 can be adjusted to accommodate different types of cells.

[0032] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A cell stacking device, characterized in that, include: Stacking table (10); pressing knife assembly (20), including mounting base (21) and pressing knife body (22), one end of the pressing knife body (22) is connected to the mounting base (21), and the other end extends above the stacking table (10). The end of the pressing knife body (22) away from the mounting base (21) includes a first pressing part (2221) and a second pressing part (2222). The second pressing part (2222) is located on the side close to the edge of the stacking table (10). Both the first pressing part (2221) and the second pressing part (2222) are rounded, and the radius of the first pressing part (2221) is greater than the radius of the second pressing part (2222).

2. The cell stacking device according to claim 1, characterized in that, The radius of the first pressing part (2221) ranges from 6mm to 12mm.

3. The cell stacking device according to claim 2, characterized in that, The radius of the second pressing part (2222) ranges from 1mm to 4mm.

4. The cell stacking apparatus according to any one of claims 1-3, characterized in that, The distance between the outer edge of the pressing body (22) and the edge of the stacking table (10) is L, and the range of L is 2mm-4mm.

5. The cell stacking apparatus according to any one of claims 1-3, characterized in that, The pressing body (22) includes a first surface (221) and a second surface (222). The second surface (222) is located on the side close to the stacking table (10). The first surface (221) and the second surface (222) are arranged opposite to each other along the thickness direction of the pressing body (22). The area of ​​the second surface (222) is larger than the area of ​​the first surface (221).

6. The cell stacking device according to claim 5, characterized in that, The cross-section of the pressure knife body (22) is an isosceles trapezoid.

7. The cell stacking device according to claim 5, characterized in that, Both the first pressing part (2221) and the second pressing part (2222) are located on the second surface (222).

8. The cell stacking apparatus according to any one of claims 1-3, characterized in that, The pressure knife body (22) is provided with a hole (223) that runs through the thickness direction.

9. The cell stacking apparatus according to any one of claims 1-3, characterized in that, Two pressure knife assembly units are symmetrically distributed on both sides of the stacking stage (10), and each pressure knife assembly unit includes two pressure knife assemblies (20) spaced apart.

10. The cell stacking apparatus according to any one of claims 1-3, characterized in that, The cell stacking device also includes a lifting mechanism and a base. One end of the lifting mechanism is mounted on the base, and the other end is connected to the mounting base (21). The lifting mechanism is used to drive the pressing knife assembly (20) to lift.

11. The cell stacking device according to claim 10, characterized in that, The cell stacking device further includes a horizontal drive mechanism connected to the base, which drives the base to move toward or away from the stacking stage (10).

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