Collecting plate and battery cell

Abstract

The invention relates to the technical field of batteries, in particular to a collector plate and a battery cell. A first bulge protruding towards the outside of the battery cell is formed on the circumferential edge of the current collecting plate, and is connected with the battery cell shell; a protruding connecting part is formed on the side, facing the interior of the battery cell, of the current collecting disc, the connecting part comprises a second protrusion and a third protrusion which are arranged at an interval, the second protrusion is connected to a tab on the pole group in a pressing mode, and the third protrusion extends into a through hole in the pole group; and a communicating hole penetrating through the flow collecting plate is formed in the connecting part. According to the invention, bad conditions such as short circuit or large self-discharge of the battery caused by the splashing of welding slag into the battery cell when the collector plate is welded with the battery cell shell can be prevented, and the second bulge is crimped on the tab on the pole group, so that the contact area between the collector plate and the tab can be reduced, the compaction of the tab and the collector plate is ensured, and the welding connection is facilitated; and the third bulge extends into the through hole, so that the problem that the exhaust passage in the battery cell is blocked or the area is reduced due to the looseness of the pole piece of the pole group can be prevented to a certain extent.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a current collector and a battery cell. Background Technology

[0002] Cylindrical batteries are widely used due to their high energy density and good rate performance. A battery consists of electrode arrays, current collectors, and a casing. Currently, one end of the current collector is integrally pressed onto the tabs of the electrode array and welded together. This results in a large contact area between the current collector and the tabs, making it easy for the tabs and current collector to not be tightly pressed together during welding, leading to a high rate of incomplete welds. The other end of the current collector is welded to the battery casing. During welding, weld slag can easily splatter into the battery, damaging the electrode arrays and affecting battery performance. Furthermore, the battery casing has an injection hole. After battery assembly, electrolyte needs to be injected into the battery from the outside through this hole. Electrolyte can easily accumulate on the surface of the current collector, leading to defects such as affecting the battery's charge / discharge rate and increasing internal resistance. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a current collector and a battery cell to solve the problems of existing current collectors being integrally pressed onto the tabs, which makes it easy for the tabs and current collectors to have poor solder joints, and when the current collector is welded to the casing, the solder slag is easy to splash into the battery cell, reducing the battery cell's performance and safety, and affecting the product quality of the battery cell.

[0004] The first aspect of the present invention provides a current collector, wherein a first protrusion protruding toward the outside of the battery cell is formed on the circumferential edge of the current collector, and the first protrusion is connected to the battery cell housing; The current collector has a protruding connecting portion on the side facing the inside of the cell. The connecting portion includes a second protrusion and a third protrusion spaced apart. The second protrusion is pressed against the tab on the electrode group, and the third protrusion extends into the through hole on the electrode group. The connecting part has a through hole that passes through the collector plate to allow the electrolyte to pass through.

[0005] Preferably, the connecting hole includes a first connecting hole formed on the second protrusion and a second connecting hole formed on the third protrusion.

[0006] Preferably, the area enclosed by the circumferential edge of the projection of the collector plate onto a plane perpendicular to the axis of the through hole is S11, in mm. 2 The total area of ​​the projection of the second protrusion onto a plane perpendicular to the axis of the through hole is S12, in mm. 2 30%≤S12 / S11≤80%.

[0007] Preferably, the battery cell housing has an injection hole, and the injection hole, the second connecting hole, and the through hole are coaxially arranged. Preferably, the area of ​​the injection hole is S, in mm. 2 The total area of ​​the connecting holes is S1, in mm. 2 ; 1≤S1 / S≤5.

[0008] Preferably, the through hole has a radial dimension of D1 in mm; the third protrusion has a radial dimension of D2 in mm; and 50% ≤ D2 / D1 ≤ 85%. Preferably, the distance between the end of the second protrusion facing the inside of the cell and the end of the third protrusion facing the inside of the cell along the axial direction of the cell is L, in mm; the height of the electrode group along the axial direction of the cell is L1, in mm; 5%≤L / L1≤10%.

[0009] Preferably, the height of the second protrusion along the axial direction of the battery cell is H, in mm; the thickness of the current collector along the axial direction of the battery cell is T, in mm; 0.5≤H / T≤4.

[0010] Preferably, the third protrusion is disposed in the middle of the collector plate, and multiple second protrusions are provided, with the multiple second protrusions arranged circumferentially around the third protrusion.

[0011] A second aspect of the present invention provides a battery cell comprising the current collector as described in any of the above technical solutions.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: The current collector of this invention has a first protrusion extending outward from the cell along its circumferential edge. This first protrusion connects to the cell casing, preventing welding slag from splashing into the cell during welding and causing short circuits or excessive self-discharge. A protruding connecting portion is formed on the side of the current collector facing the cell interior, with a through-hole allowing electrolyte to pass through. The connecting portion includes a second and a third protrusion spaced apart. The second protrusion presses against the tabs on the electrode assembly, reducing the contact area between the current collector and the tabs, ensuring tight contact, aiding welding, improving welding defects such as incomplete welds, and increasing welding yield. The third protrusion extends into the through-hole on the electrode assembly, preventing blockage or reduced area of ​​the venting channels within the cell due to loose electrode sheets, thereby improving cell quality and ensuring safe performance.

[0013] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0014] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of the collector disk provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the collector disk from another perspective, provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the collector disk provided in an embodiment of the present invention from another perspective. Figure 4 For along Figure 3 Cross-sectional view taken at point AA in the middle; Figure 5 This is a schematic diagram of the liquid injection hole on the battery cell housing assembled with the current collector provided in the embodiment of the present invention; Figure 6 This is a schematic diagram of the pole assembly assembled with the current collector provided in the embodiment of the present invention.

[0016] Icons: 10-Collector's plate; 11-First protrusion; 12-Connecting part; 121-Second protrusion; 122-Third protrusion; 100-Connecting hole; 101-First connecting hole; 102-Second connecting hole; 20-Electrode group; 21-Through hole; 30-Injection hole. Detailed Implementation

[0017] The following detailed embodiments are provided to help the reader gain a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will be apparent after understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein; changes that will be apparent after understanding the disclosure of this application are possible, except for operations that must occur in a specific order. Furthermore, for clarity and brevity, descriptions of features known in the art may be omitted.

[0018] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0019] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, it may be directly "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, or there may be one or more other elements in between. In contrast, when an element is described as being "directly on" another element, "directly connected to" another element, "directly bonded to" another element, "directly on" another element, or "directly covering" another element, there may be no other elements in between.

[0020] As used herein, the term “and / or” includes any one of the relevant items listed and any combination of any two or more items.

[0021] Although terms such as “first,” “second,” and “third” may be used herein to describe individual components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts are not limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Therefore, without departing from the teachings of the examples described herein, the first component, assembly, region, layer, or part referred to as the second component, assembly, region, layer, or part may also be referred to as the second component, assembly, region, layer, or part.

[0022] For ease of description, spatial relation terms such as “above,” “upper,” “below,” and “lower” are used herein to describe the relationship between one element and another, as shown in the accompanying drawings. Such spatial relation terms are intended to include not only the orientation depicted in the drawings but also different orientations of the device during use or operation. For example, if the device in the drawings is flipped, an element described as being “above” or “upper” relative to another element will subsequently be “below” or “lower” relative to that other element. Therefore, the term “above” includes both “above” and “below” orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relation terms used herein will be interpreted accordingly.

[0023] The terminology used herein is for the purpose of describing various examples only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms “comprising,” “including,” and “having” enumerate the stated features, quantities, operations, components, elements, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0024] Variations in the shapes shown in the accompanying drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include changes in shape that may occur during manufacturing.

[0025] The features of the examples described herein can be combined in various ways that will be apparent upon understanding the disclosure of this application. Furthermore, although the examples described herein have a wide variety of constructions, other constructions are possible, as will be apparent upon understanding the disclosure of this application.

[0026] According to a first aspect of the present invention, a manifold is provided. The specific structure of the collector disk according to this embodiment will be described below.

[0027] In this embodiment, as Figures 1 to 4 As shown, the current collector 10 is formed as a plate or sheet structure. The circumferential edge of the current collector 10 has a first protrusion 11 protruding towards the outside of the battery cell. The first protrusion 11 is connected to the battery cell shell. This increases the thickness of the circumferential edge of the current collector 10, preventing welding slag from splashing into the battery cell during welding of the current collector 10 to the battery cell shell, which could cause short circuits or large battery self-discharge.

[0028] Specifically, the first protrusion 11 is formed as a closed ring structure, and the shape of the first protrusion 11 is the same as the outer edge shape of the collecting plate 10. For example, when the collecting plate 10 is formed as a circular plate or sheet structure, the first protrusion 11 is formed as a circular ring structure.

[0029] It should be noted that the cell casing has an injection hole 30 for injecting electrolyte into the cell; the cell casing includes a cell housing with an internal cavity for housing the electrode assembly 20 and a cell cover plate for sealing the cavity. The first protrusion 11 can be welded to the cell housing. The injection hole 30, as described below, can be formed as a through-hole structure penetrating the cell cover plate. It should be further noted that the radial direction of the cell... Figure 4 The horizontal direction from the perspective of the cell's axis is... Figure 4 The vertical direction from the perspective of view.

[0030] In this embodiment, as Figures 1 to 4 As shown, a protruding connecting portion 12 is formed on the side of the current collector 10 facing the inside of the battery cell. The connecting portion 12 can be formed on the current collector 10 by a stamping process. However, the protruding connecting portion 12 is not limited to being formed by stamping; it can also be formed by welding or other processing methods, as long as it can form a protrusion on the surface of the current collector 10 facing the inside of the battery cell. A through hole 100 is provided on the connecting portion 12, penetrating the current collector 10, to allow the electrolyte to pass through.

[0031] Specifically, such as Figures 1 to 5 As shown, the connecting part 12 includes a second protrusion 121 and a third protrusion 122 spaced apart. The second protrusion 121 and the third protrusion 122 do not contact each other in the axial and radial directions of the cell. The second protrusion 121 is pressed against the tab on the electrode group 20, thereby reducing the contact area between the current collector 10 and the tab, ensuring that the tab and the current collector 10 are pressed tightly, which helps to weld the connection, improve welding defects such as incomplete welding, improve welding yield, and thus improve the product quality of the cell and ensure the performance of the cell. The third protrusion 122 extends into the through hole 21 on the electrode group 20, which can, to a certain extent, prevent the problem of blockage or reduction of the exhaust channel in the cell caused by the loose electrode sheets of the electrode group 20, thereby meeting the cell exhaust requirements and ensuring the safety performance of the cell.

[0032] In this embodiment, the axis of the through hole 21 on the electrode assembly 20 is coaxial with the central axis of the electrode assembly 20, and the through hole 21 penetrates the body of the electrode assembly 20.

[0033] Furthermore, in this embodiment, as Figures 1 to 3 As shown, the third protrusion 122 is located in the middle of the current collector 10, ensuring that the third protrusion 122 can extend into the through hole 21 on the electrode assembly 20; preferably, multiple second protrusions 121 are provided, and multiple second protrusions 121 are arranged circumferentially around the third protrusion 122, so as to ensure that the second protrusions 121 can uniformly press the electrode tab. When the current collector 10 is a circular plate structure, each second protrusion 121 can be formed into a fan-shaped ring structure.

[0034] In this embodiment, as Figures 1 to 4 As shown, the connecting hole 100 includes a first connecting hole 101 formed on the second protrusion 121 and a second connecting hole 102 formed on the third protrusion 122. The first connecting hole 101 is shown in the figure. Figure 3 As shown in the shaded area of ​​the central fan-shaped ring, it is located on the side of the second protrusion 121 facing the third protrusion 122 in the radial direction of the cell; see also the second connecting hole 102. Figure 3As shown in the shaded area of ​​the circle, it is located in the middle of the third protrusion 122, making the third protrusion 122 form a tubular structure. After the battery cell is assembled, it can enter the battery cell from the outside through the liquid injection hole 30 and pass through the first connecting hole 101 or the second connecting hole 102 to wet the electrode group 20, thereby increasing the wetting speed and avoiding liquid leakage caused by electrolyte accumulation.

[0035] In this embodiment, the injection hole 30, the second connecting hole 102 on the second protrusion 121 and the through hole 21 on the electrode assembly 20 are coaxially arranged, thereby improving the reliability of electrolyte wetting of the electrode assembly 20. In this embodiment, as Figure 5 As shown, the area of ​​the injection hole 30 is S, in mm. 2 ,Right now Figure 5 The area enclosed by the walls of the circular injection hole 30 shown is S; the total area of ​​the connecting holes 100 is S1, in mm. 2 ,Right now Figure 3 The total area of ​​the shaded region shown is S1, 1≤S1 / S≤5. This avoids the situation where the liquid injection efficiency and the wetting speed of the electrode group 20 are reduced due to the parameter S1 / S being too small, which may cause liquid leakage. It also avoids the situation where the risk of welding slag falling into the cell is increased due to the parameter S1 / S being too large.

[0036] Furthermore, in this embodiment, as Figure 3 As shown, the area enclosed by the circumferential edge of the projection of the collector plate 10 onto a plane perpendicular to the axis of the through hole 21 is S11, in mm. 2 ;exist Figure 3 From this perspective, the area enclosed by the outermost edge of the manifold 10 is S11, that is, the area enclosed by the outer ring wall of the first protrusion 11 is S11. The total area of ​​the projection of the second protrusion 121 onto the plane perpendicular to the axis of the through hole 21 is S12, in mm. 2 That is, the total area of ​​the portion of the second protrusion 121 excluding the first connecting hole 101 is S12, see [reference]. Figure 3 As shown, the sum of the areas of all the second protrusions 121 excluding the shaded areas of the first connecting hole 101 is S12; 30%≤S12 / S11≤80%, thus avoiding the parameter S12 / S11 being too small, which would affect the welding area of ​​the electrode and the current collector 10, thereby affecting the current flow; and also avoiding the parameter S12 / S11 being too large, which would result in a large contact area between the current collector 10 and the electrode, causing an increased defect rate of welding defects such as cold solder joints.

[0037] The reliability of the 30%≤S12 / S11≤80% constraint in this invention was verified through multiple sets of cell assembly tests. In each set of tests, multiple cells of the same size were assembled, and the test results are shown in Table 1.

[0038] Table 1

[0039] The reliability of the limiting condition 1≤S1 / S≤5 in this invention was verified through multiple sets of cell assembly tests. In each set of tests, multiple cells of the same size were assembled. The test results are shown in Table 2.

[0040] Table 2

[0041] In this embodiment, as Figure 4 and Figure 6 As shown, the through hole 21 on the electrode group 20 has a radial dimension of D1 in the cell, and the outer wall of the third protrusion 122 has a radial dimension of D2 ... The reliability of the 50%≤D2 / D1≤85% constraint in this invention was verified through multiple sets of cell assembly tests. In each set of tests, multiple cells of the same size were assembled, and the test results are shown in Table 3.

[0042] Table 3

[0043] In this embodiment, as Figure 4 and Figure 6 As shown, the distance between the end of the second protrusion 121 facing the inside of the cell and the end of the third protrusion 122 facing the inside of the cell is L, in mm; the height of the electrode group 20 in the axial direction of the cell is L1, in mm; 5%≤L / L1≤10%, thus avoiding the situation where the electrode sheet cannot be reliably supported and does not become loose due to the parameter L / L1 being too small; and also avoiding the increase in material cost due to the parameter L / L1 being too large.

[0044] The reliability of the 5%≤L / L1≤10% limiting condition in this invention was verified through multiple sets of experiments. The test results are shown in Table 4.

[0045] Table 4

[0046] In this embodiment, as Figure 4As shown, the height dimension of the second protrusion 121 in the axial direction of the battery cell is H, that is, the distance between the side of the second protrusion 121 facing the inside of the battery cell and the side of the current collector 10 body facing the inside of the battery cell in the axial direction is H, in mm; the thickness dimension of the current collector 10 in the axial direction of the battery cell is T, in mm, that is, the plate thickness or sheet thickness of the plate-shaped or sheet-shaped current collector 10 is T; 0.5≤H / T≤4, thus ensuring that the second protrusion 121 and the electrode tab are reliably pressed together, and also avoiding excessive occupation of the space of the battery cell in the axial direction, which would affect the energy density of the battery cell.

[0047] The reliability of the 0.5≤H / T≤4 constraint in this invention was verified through multiple sets of cell assembly tests. In each set of tests, multiple cells of the same size were assembled. The test results are shown in Table 5.

[0048] Table 5

[0049] According to the present invention, a current collector has a first protrusion extending outward toward the cell's exterior along its circumferential edge. This first protrusion connects to the cell's outer casing, preventing welding slag from splashing into the cell during welding and causing short circuits or excessive self-discharge. A protruding connecting portion is formed on the side of the current collector facing the cell's interior, with a through-hole allowing electrolyte to pass through. The connecting portion includes a second and a third protrusion spaced apart. The second protrusion presses against the tabs on the electrode assembly, reducing the contact area between the current collector and the tabs, ensuring tight contact, facilitating welding, improving welding defects such as incomplete welds, and increasing welding yield. The third protrusion extends into the through-hole on the electrode assembly, preventing blockage or reduced area of ​​the cell's venting channels due to loose electrode sheets, thereby improving cell quality and ensuring safe performance.

[0050] The battery cell provided by the present invention includes the current collector as described above, and thus has all the above-mentioned beneficial effects, which will not be repeated here.

[0051] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A collector disk, characterized in that, The circumferential edge of the current collector has a first protrusion protruding outward toward the outside of the battery cell, and the first protrusion is connected to the battery cell casing; The current collector has a protruding connecting portion on the side facing the inside of the cell. The connecting portion includes a second protrusion and a third protrusion spaced apart. The second protrusion is pressed against the tab on the electrode group, and the third protrusion extends into the through hole on the electrode group. The connecting part has a through hole that passes through the collector plate to allow the electrolyte to pass through; The connecting hole includes a first connecting hole formed on the second protrusion and a second connecting hole formed on the third protrusion; The area enclosed by the circumferential edge of the projection of the collector plate onto a plane perpendicular to the axis of the through hole is S11, in mm. 2 The total area of ​​the projection of the second protrusion onto a plane perpendicular to the axis of the through hole is S12, in mm. 2 30%≤S12 / S11≤80%.

2. The collector disk according to claim 1, characterized in that, The battery cell casing has an injection hole, and the injection hole, the second connecting hole, and the through hole are coaxially arranged.

3. The collector disk according to claim 2, characterized in that, The area of ​​the injection hole is S, in mm. 2 The total area of ​​the connecting holes is S1, in mm. 2 ; 1≤S1 / S≤5.

4. The collector disk according to claim 1, characterized in that, The through hole has a radial dimension of D1 in mm; the third protrusion has a radial dimension of D2 in mm; 50% ≤ D2 / D1 ≤ 85%.

5. The collector disk according to claim 1, characterized in that, Along the axial direction of the cell, the distance between the end of the second protrusion facing the inside of the cell and the end of the third protrusion facing the inside of the cell is L, in mm; the height of the electrode group along the axial direction of the cell is L1, in mm; 5%≤L / L1≤10%.

6. The collector disk according to claim 1, characterized in that, The height of the second protrusion along the axial direction of the battery cell is H, in mm; the thickness of the current collector along the axial direction of the battery cell is T, in mm; 0.5≤H / T≤4.

7. The collector disk according to claim 1, characterized in that, The third protrusion is located in the middle of the collector plate, and multiple second protrusions are provided, with the multiple second protrusions arranged circumferentially around the third protrusion.

8. A battery cell, characterized in that, Includes the manifold as described in any one of claims 1 to 7.

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