Pole piece and battery cell with same

Abstract

The utility model provides a kind of pole piece and the electric core with it, pole piece includes: current collector, the surface of current collector is provided with active material layer;Tab, one end of tab is set on current collector, part tab covers on active material layer;Bonding part, tab and active material layer are adhesively arranged by bonding part;Welding tab, welding on the surface of tab away from active material layer. By the scheme, it can solve the problem of the active material layer in the prior art forming tab slot, and welding the welding tab at the tab slot, which can easily cause the active material layer near the tab slot to fall off, affecting the performance of the electric core.

Description

Technical Field

[0001] This utility model relates to the field of battery cell technology, and more specifically, to an electrode sheet and a battery cell having the same. Background Technology

[0002] The electrode includes a current collector and an active material layer disposed on the surface of the current collector. In the prior art, part of the active material layer is usually removed by laser to form an electrode tab groove, the bottom of the electrode tab groove is exposed to the current collector, and then the welding tab is welded to the exposed current collector of the electrode tab groove by welding.

[0003] However, using the above method, the energy of the laser beam is not limited to the target area, but also spreads to the surrounding area. Even outside the designated tab groove area and on the side of the current collector away from the tab groove, the active material layer may be affected by thermal stress, causing damage to the microstructure of the nearby active material layer and the shedding of the active material layer, affecting the performance of the cell. Furthermore, after the tab groove is formed, the exposed current collector area is directly welded to the welding tab. The heat radiation during the welding process may cause the active material layer near the tab groove and the active material layer on the side of the current collector away from the tab groove to detach, affecting the performance of the cell. Utility Model Content

[0004] This invention provides an electrode sheet and a battery cell having the same, to solve the problem in the prior art where forming a tab groove in the active material layer and welding the tab to the tab groove can easily lead to the active material layer near the tab groove falling off, thus affecting the performance of the battery cell.

[0005] According to one aspect of the present invention, an electrode sheet is provided, comprising: a current collector having an active material layer disposed on its surface; an ear having one end disposed on the current collector and a portion of the ear covering the active material layer; an adhesive portion for bonding the ear and the active material layer; and a welding tab for welding onto the surface of the ear away from the active material layer.

[0006] Furthermore, the lug includes an interconnected bent segment and a main body segment. The first end of the bent segment is integrally connected to the current collector, and the second end of the bent segment extends toward the side where the active material layer is located. One end of the main body segment is connected to the second end of the bent segment. The main body segment covers the active material layer, and the welding tab is welded to the surface of the main body segment away from the active material layer.

[0007] Furthermore, the adhesive portion covers at least a portion of the main body segment and covers an active material layer located on the outer periphery of the main body segment, and the adhesive portion simultaneously bonds the main body segment and the active material layer.

[0008] Furthermore, the adhesive portion is made of insulating material and covers at least part of the end of the welding tab that is welded to the main body section.

[0009] Furthermore, the orthographic projection of the portion of the welding tab that is bonded to the adhesive portion is located within the outline of the adhesive portion; the orthographic projection of the main body segment on the adhesive portion is located within the outline of the adhesive portion.

[0010] Furthermore, the dimension of the adhesive portion along the length of the current collector is L1, and the dimension of the main body segment along the length of the current collector is L2. The dimension of the adhesive portion along the width direction of the current collector is L3, and the dimension of the main body section along the width direction of the current collector is L4.

[0011] Furthermore, the length of the welding tab is L5, and the orthographic projection of the portion of the welding tab that is welded to the lead lug on the lead lug along the length direction of the welding tab is L6.

[0012] Furthermore, the orthographic projection of the portion of the welding tab that is welded to the lead-in tab onto the lead-in tab along the length of the welding tab is L6, and the portion of the lead-in tab covering the active material layer along the length of the welding tab is L4. The orthographic projection of the portion of the welding tab to the lead-in tab onto the lead-in tab along the width direction of the welding tab is L7, and the dimension of the portion of the lead-in tab covering the active material layer along the width direction of the welding tab is L2.

[0013] Furthermore, the thickness of the lead lug is d1, and the thickness of the welding electrode lug is d2.

[0014] According to another aspect of the present invention, a battery cell is provided, which includes the aforementioned electrode plates.

[0015] By applying the technical solution of this utility model, the welding tab is welded to the lead-in lug, and the lead-in lug is bonded to the active material layer through an adhesive part. This avoids the step of removing part of the active material layer with a laser to form the tab groove, and eliminates the situation of welding the welding tab to the exposed current collector of the tab groove. This solution reduces the risk of active material layer detachment and improves the stability of the battery cell. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0017] Figure 1 This invention provides a schematic diagram of the structure of an electrode sheet with the first surface of the current collector facing upwards when the lug is in the unfolded state.

[0018] Figure 2 This invention provides a partial structural schematic diagram of an electrode sheet with the second surface of the current collector facing upwards when the lead ear is bent and abuts against the active material layer and the adhesive part is not bonded to the lead ear.

[0019] Figure 3 This invention provides a partial structural schematic diagram of an electrode sheet with the adhesive portion covering the main body section of the lug and part of the welded electrode lug, and the second surface of the current collector facing upwards.

[0020] Figure 4 A cross-sectional view of a portion of the structure of the electrode provided by this utility model is shown.

[0021] The above figures include the following reference numerals:

[0022] 10. Current collector;

[0023] 20. Active substance layer;

[0024] 30. Ear opening; 31. Bend section; 32. Main body section;

[0025] 40. Adhesive part;

[0026] 50. Welding electrode tabs. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present utility model or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0028] like Figures 1 to 4 As shown, this embodiment of the present invention provides an electrode sheet, which includes a current collector 10, a lug 30, an adhesive portion 40, and a welding tab 50. An active material layer 20 is disposed on the surface of the current collector 10; one end of the lug 30 is disposed on the current collector 10, and a portion of the lug 30 covers the active material layer 20; the lug 30 and the active material layer 20 are bonded together by the adhesive portion 40; the welding tab 50 is welded to the surface of the lug 30 away from the active material layer 20.

[0029] By applying the technical solution of this utility model, the welding tab 50 is welded to the lead ear 30, and the lead ear 30 is bonded to the active material layer 20 through the adhesive part 40. This avoids the step of removing part of the active material layer 20 by laser to form the tab groove, and also eliminates the need to weld the welding tab 50 to the exposed current collector 10 of the tab groove. This solution reduces the risk of the active material layer 20 falling off and improves the stability of the battery cell.

[0030] Furthermore, the lead-in tab 30 includes a bent segment 31 and a main body segment 32 connected to each other. The first end of the bent segment 31 is integrally connected to the current collector 10, and the second end of the bent segment 31 extends towards the side where the active material layer 20 is located. One end of the main body segment 32 is connected to the second end of the bent segment 31, and the main body segment 32 covers the active material layer 20. The welding tab 50 is welded to the surface of the main body segment 32 away from the active material layer 20. Integrating the first end of the bent segment 31 with the current collector 10 can improve the stability of the connection between the bent segment 31 and the current collector 10.

[0031] Understandably, the ear 30 itself is an integrated structure.

[0032] Specifically, when processing the current collector 10 and the lug 30, the foil can be cut to form an integrated current collector 10 and lug 30.

[0033] In this embodiment, the lug 30 is disposed at the edge of the current collector 10 along its length. The length direction of the current collector 10 is perpendicular to the length direction of the welding lug 50. Figures 1 to 3 In the middle, the X direction is the length direction of the current collector 10, and the Y direction is the width direction of the current collector 10.

[0034] Furthermore, the current collector 10 has a first surface and a second surface arranged opposite to each other, and the lug 30 has a welding surface and an abutting surface. Before the lug 30 is bent, the welding surface of the lug 30 and the first surface of the current collector 10 are located on the same side as the electrode, and the abutting surface of the lug 30 and the second surface of the current collector 10 are located on the same side as the electrode.

[0035] During electrode fabrication, an active material layer 20 is first coated on both the first and second surfaces. Then, one end of the welding tab 50 is welded to the welding surface of the lead 30, and the other end of the welding tab 50 extends towards the current collector 10. Next, the lead 30 is bent so that its contact surface abuts against the active material layer 20 on the second surface of the current collector 10. Finally, the main body segment 32 of the lead 30 is bonded to the active material layer 20 on the second surface using the adhesive portion 40. This arrangement further reduces the impact of heat radiation during the welding process on the active material layer 20 and the current collector 10 coated with the active material layer 20.

[0036] In this embodiment, the adhesive portion 40 covers at least a portion of the main body segment 32 and the active material layer 20 located on the outer periphery of the main body segment 32. The adhesive portion 40 simultaneously bonds the main body segment 32 and the active material layer 20. This configuration improves the tightness of the contact between the main body segment 32 and the active material layer 20, and enhances the stability of the adhesion between the adhesive portion 40 and the main body segment 32 and the active material layer 20.

[0037] Furthermore, the adhesive portion 40 is made of insulating material and covers at least part of the end of the welding tab 50 that is welded to the main body segment 32. This arrangement creates a physical barrier between the adhesive portion 40 and the separator of the battery cell, reducing the possibility of the welding tab 50 puncturing the separator of the battery cell and improving the safety of the battery cell.

[0038] Specifically, adhesive tape can be used for the adhesive part 40.

[0039] Specifically, the orthographic projection of the portion of the welding tab 50 that is bonded to the adhesive portion 40 onto the adhesive portion 40 lies within the outline of the adhesive portion 40. This arrangement ensures that the adhesive portion 40 covers the portion of the welding tab 50 that is bonded to the adhesive portion 40, thus preventing direct contact between the welding tab 50 and the separator of the battery cell.

[0040] like Figures 2 to 4 As shown, further, the orthographic projection of the main body segment 32 onto the adhesive portion 40 is located within the outline of the adhesive portion 40.

[0041] Specifically, the edge of the adhesive portion 40 near the bending section 31 and the edge where the current collector 10 connects to the bending section 31 are flush. The dimension of the adhesive portion 40 along the length direction of the current collector 10 is larger than the dimension of the main body section 32 along the length direction of the current collector 10; the dimension of the adhesive portion 40 along the width direction of the current collector 10 is larger than the dimension of the main body section 32 along the width direction of the current collector 10.

[0042] Specifically, the dimension of the adhesive portion 40 along the length direction of the current collector 10 is L1, and the dimension of the main body segment 32 along the length direction of the current collector 10 is L2. If the length of the adhesive portion 40 along the current collector 10 is too long, the adhesive portion 40 will cover a large amount of the active material layer 20, reducing the effective area of ​​the active material layer 20 used for electrochemical reactions and affecting the capacity of the battery cell; if the length of the adhesive portion 40 along the current collector 10 is too short, the bonding effect of the adhesive portion 40 to the main body segment 32 will be affected. In summary, this solution will... The numerical values ​​are set within the above range, which can simultaneously take into account the effective reaction area of ​​the active material layer 20 and the adhesion effect on the main body segment 32.

[0043] in, Specifically, it can be set to 0.5, 0.7, or 0.9, etc.

[0044] Similarly, in this design, the dimension of the adhesive portion 40 along the width direction of the current collector 10 is L3, and the dimension of the main body segment 32 along the width direction of the current collector 10 is L4.

[0045]

[0046] in, Specifically, it can be set to 0.5, 0.7, or 0.9, etc.

[0047] In this embodiment of the solution, the length of the welding tab 50 is L5, and the orthographic projection of the portion of the welding tab 50 and the lead lug 30 onto the lead lug 30 along the length direction of the welding tab 50 is L6. like If the contact area between the welding tab 50 and the lead-in lug 30 is too small, the mechanical strength and electrical connection quality of the weld joint may be affected, potentially impacting the stability of the weld between the welding tab 50 and the lead-in lug 30. If the length is too large, the protrusion of the welding tab 50 from the lug 30 at the end furthest from the current collector 10 will be too short, making it difficult to connect the welding tab 50 to other components. This solution will... By setting it within the above range, it is possible to simultaneously ensure the stability of welding the welding tab 50 and the lead-in tab 30, as well as the convenience of connecting the welding tab 50 to external components.

[0048] It is understandable that the orthographic projection of the welding tab 50 onto the main body section 32 along the length of the welding tab 50 is L6.

[0049] Furthermore, the portion of the lug 30 covering the active material layer 20 has a dimension of L4 along the length of the welding lug 50. like If the contact area between the welding tab 50 and the lead-in lug 30 is too small, it will affect the stability of the welding between the welding tab 50 and the lead-in lug 30; if If the size is too large, the welding tab 50 may shift during the welding process, and if the tab 30 bends, there is a risk that the welding tab 50 may come into contact with the active material layer 20.

[0050] in, Specifically, it can be set to 0.5, 0.7, or 0.9, etc.

[0051] Similarly, the orthographic projection of the portion of the welding tab 50 and the lead tab 30 onto the lead tab 30 along the width direction of the welding tab 50 is L7, and the portion of the lead tab 30 covering the active material layer 20 along the width direction of the welding tab 50 is L2.

[0052] It is understandable that the orthographic projection of the main body segment 32 onto the active material layer 20 has a dimension L2 along the width direction of the welding tab 50.

[0053] in, Specifically, it can be set to 0.5, 0.7, or 0.9, etc.

[0054] Furthermore, the thickness of the lead lug 30 is d1, and the thickness of the welding electrode lug 50 is d2. If the thickness of the welding tab 50 is too thin, it will affect the structural strength of the welding tab 50; if the thickness of the welding tab 50 is too thick, after the adhesive part 40 covers the welding tab 50 and the lead ear 30, the structure of this part will be too thick. During the battery cell packaging, the excessively thick welding tab 50 will increase the internal pressure of the battery cell, causing the battery cell shell to deform. Furthermore, if the battery cell is subjected to impact or compression, it may cause stress concentration, reducing the impact resistance and durability of the battery cell.

[0055] in, It can be set to 3, 4 or 5.

[0056] The specific steps for preparing the electrode in this scheme include:

[0057] Cut the foil to form an integrated current collector 10 and lug 30; such that the welding surface of the lug 30 is on the same side as the first surface of the current collector 10, and the abutting surface of the lug 30 is on the same side as the second surface of the current collector 10.

[0058] The active material is coated on both surfaces of the current collector 10 and dried to form an active material layer 20 on each of the two surfaces of the current collector 10.

[0059] One end of the welding tab 50 is welded to the welding surface of the lead tab 30, and the other end extends toward the side where the current collector 10 is located, ensuring that the other end of the welding tab 50 extends above the active material layer 20 on the first surface of the current collector 10.

[0060] The lead ear 30 with the welded tab 50 is bent toward the side where the second surface of the current collector 10 is located, so that the lead ear 30 forms a bent section 31 and a main body section 32 that are connected to each other, wherein the bent section 31 is located on the side of the current collector 10; the contact surface of the main body section 32 abuts against the active material layer 20 on the second surface of the current collector 10, and the side where the welded surface of the main body section 32 is located is away from the active material layer 20. At this time, the welded tab 50 is located on the side of the main body section 32 away from the second surface, and the other end of the welded tab 50 extends away from the current collector 10.

[0061] After the adhesive portion 40 covers both the end of the welding tab 50 and the main body section 32 that are welded together and the main body section 32 of the lead ear 30, the adhesive portion 40 is then bonded to the active material layer 20 on the second surface.

[0062] This utility model provides a battery cell in embodiment two, which includes the electrode sheet of embodiment one.

[0063] The beneficial effects of this plan include:

[0064] 1. Welding the welding tab 50 onto the lead tab 30 and bonding the lead tab 30 onto the active material layer 20 through the adhesive part 40 can avoid the step of removing the positive active material layer 20 by laser to form the tab groove, and avoid the situation where the positive active material layer 20 falls off due to laser heat radiation.

[0065] 2. Welding the welding tab 50 onto the lug 30 integrated with the current collector 10 can reduce the impact of welding heat on the current collector 10 and the active material layer 20 during the welding process.

[0066] 3. After the adhesive part 40 covers the end of the welding tab 50 that is welded to the main body section 32 and the main body section 32 of the lead tab 30, the adhesive part 40 is then bonded to the active material layer 20. The above arrangement enables the adhesive part 40 to bond the lead tab 30 to the active material layer 20 while also providing physical isolation between the welding tab 50 and the separator, reducing the possibility of the welding tab 50 puncturing the separator and improving the safety of the battery cell.

[0067] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0068] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as exemplary only and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0069] In the description of this utility model, it should be understood that the directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms 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, and therefore should not be construed as a limitation on the scope of protection of this utility model. The directional terms "inner" and "outer" refer to the inner and outer contours of each component itself.

[0070] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0071] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this utility model.

[0072] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An electrode sheet, characterized in that, The electrode includes: A current collector (10) having an active material layer (20) disposed on its surface; Ear (30), one end of the ear (30) is disposed on the current collector (10), and part of the ear (30) covers the active material layer (20); The adhesive part (40) is used to bond the ear (30) and the active material layer (20). Welding tabs (50) are welded to the surface of the lugs (30) away from the active material layer (20).

2. The electrode sheet according to claim 1, characterized in that, The lug (30) includes a bent section (31) and a main body section (32) connected to each other. The first end of the bent section (31) is integrally connected to the current collector (10). The second end of the bent section (31) extends toward the side where the active material layer (20) is located. One end of the main body section (32) is connected to the second end of the bent section (31). The main body section (32) covers the active material layer (20). The welding tab (50) is welded to the surface of the main body section (32) away from the active material layer (20).

3. The electrode sheet according to claim 2, characterized in that, The adhesive portion (40) covers at least a portion of the main body segment (32) and covers the active material layer (20) located on the periphery of the main body segment (32), and the adhesive portion (40) simultaneously adheres to the main body segment (32) and the active material layer (20).

4. The electrode sheet according to claim 3, characterized in that, The adhesive portion (40) is made of insulating material and covers at least part of the end of the welding tab (50) that is welded to the main body segment (32).

5. The electrode sheet according to claim 4, characterized in that, The portion of the welding tab (50) that is bonded to the adhesive portion (40) has its orthographic projection on the adhesive portion (40) located within the outline of the adhesive portion (40); The orthographic projection of the main body segment (32) onto the adhesive portion (40) lies within the outline of the adhesive portion (40).

6. The electrode sheet according to claim 5, characterized in that, The dimension of the adhesive portion (40) along the length direction of the current collector (10) is L1, and the dimension of the main body segment (32) along the length direction of the current collector (10) is L2. The dimension of the adhesive portion (40) along the width direction of the current collector (10) is L3, and the dimension of the main body segment (32) along the width direction of the current collector (10) is L4.

7. The electrode sheet according to claim 1, characterized in that, The length of the welding tab (50) is L5, and the orthographic projection of the portion of the welding tab (50) welded to the guide lug (30) onto the guide lug (30) along the length direction of the welding tab (50) is L6.

8. The electrode sheet according to claim 1, characterized in that, The portion of the welding tab (50) welded to the guide lug (30) has its orthographic projection onto the guide lug (30) along the length of the welding tab (50) as follows: L6, the portion of the lug (30) covering the active material layer (20) has a dimension L4 along the length direction of the welding lug (50). The portion of the welding tab (50) welded to the lead tab (30) has an orthographic projection on the lead tab (30) along the width direction of the welding tab (50) of L7, and the portion of the lead tab (30) covering the active material layer (20) has an dimension of L2 along the width direction of the welding tab (50).

9. The electrode sheet according to claim 1, characterized in that, The thickness of the lug (30) is d1, and the thickness of the welding lug (50) is d2.

10. A battery cell, characterized in that, Includes the electrode as described in any one of claims 1 to 9.

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