Current collector plate and battery cell

Abstract

The present application relates to the technical field of battery, especially to a current collecting disc and a battery cell. The circumferential edge of the current collecting disc is formed with a first protrusion protruding towards the outside of the battery cell, and the first protrusion is connected with the shell of the battery cell. The side of the current collecting disc facing the inside of the battery cell is formed with a protruding connecting part, and the connecting part comprises a second protrusion and a third protrusion arranged at intervals. The second protrusion is crimped on the tab of the pole group, and the third protrusion extends into the through hole of the pole group. A communication hole is formed in the connecting part and penetrates the current collecting disc. The present application can prevent the welding slag from splashing into the inside of the battery cell when the current collecting disc is welded with the shell of the battery cell, thereby preventing short circuit or large self-discharge of the battery and other adverse conditions. The second protrusion is crimped on the tab of the pole group, which can reduce the contact area of the current collecting disc and the tab, ensure the tab and the current collecting disc to be pressed tightly, and be helpful for welding connection. The third protrusion extends into the through hole, which can prevent the exhaust passage in the battery cell from being blocked or the area from being reduced due to the loose pole piece to a certain extent.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a current collecting disc and a battery cell. BACKGROUND

[0002] Cylindrical batteries have the characteristics of high energy density and good rate performance, and are widely used. The battery includes a pole group, a current collecting disc and a shell. At present, one end of the current collecting disc is integrally crimped on the tab of the pole group for welding, so that the contact area of the current collecting disc and the tab is large, which easily causes the tab and the current collecting disc to be not pressed tightly during welding, thereby leading to a high rate of false welding. The other end of the current collecting disc is welded to the battery shell. When the current collecting disc is welded to the battery shell, welding slag is easily splashed into the battery, which can damage the pole group and affect the performance of the battery. In addition, a liquid injection hole is provided on the battery shell. After the battery is assembled, electrolyte needs to be injected into the battery from the outside of the battery through the liquid injection hole. The electrolyte is easily accumulated on the surface of the current collecting disc, which leads to defects such as affecting the charge and discharge rate of the battery and increasing the internal resistance of the battery. SUMMARY

[0003] Therefore, the purpose of the present application is to provide a current collecting disc and a battery cell to solve the problem that the current collecting disc of the prior art is integrally crimped on the tab, which easily causes false welding of the tab and the current collecting disc, and welding slag is easily splashed into the battery cell when the current collecting disc is welded to the shell, thereby reducing the use performance and safety performance of the battery cell and affecting the product quality of the battery cell.

[0004] The first aspect of the present application provides a current collecting disc, wherein a circumferential edge of the current collecting disc is formed with a first protrusion protruding towards the outside of the battery cell, and the first protrusion is connected to the shell of the battery cell.

[0005] A side of the current collecting disc facing the inside of the battery cell is formed with a protruding connecting part, the connecting part includes a second protrusion and a third protrusion arranged at intervals, the second protrusion is crimped on the tab on the pole group, and the third protrusion extends into a through hole on the pole group.

[0006] A communication hole penetrating through the current collecting disc is provided on the connecting part to allow the electrolyte to pass through.

[0007] Preferably, the communication hole includes a first communication hole provided on the second protrusion and a second communication hole provided on the third protrusion.

[0008] Preferably, the circumferential edge of the projection of the current collecting disc on a plane perpendicular to the axis of the through hole encloses an area S11 with a unit of mm 2 ; the total area of the projection of the second protrusion on a plane perpendicular to the axis of the through hole is S12 with a unit of mm 2 ; 30%≤S12 / S11≤80%.

[0009] Preferably, a liquid injection hole is formed on the shell of the battery cell, and the liquid injection hole, the second communication hole and the through hole are coaxially arranged.

[0010] Preferably, the area of the liquid injection hole is S, and the unit is mm 2 ; the total area of the communication hole is S1, and the unit is mm 2 ; 1≤S1 / S≤5.

[0011] Preferably, the size of the through hole in the radial direction of the battery cell is D1, and the unit is mm; the size of the third protrusion in the radial direction of the battery cell is D2, and the unit is mm; 50%≤D2 / D1≤85%.

[0012] Preferably, in the axial direction of the battery cell, the distance between the end of the second protrusion facing the inside of the battery cell and the end of the third protrusion facing the inside of the battery cell is L, and the unit is mm; the height dimension of the pole group in the axial direction of the battery cell is L1, and the unit is mm; 5%≤L / L1≤10%.

[0013] Preferably, the height dimension of the second protrusion in the axial direction of the battery cell is H, and the unit is mm; in the axial direction of the battery cell, the thickness dimension of the current collector plate is T, and the unit is mm; 0.5≤H / T≤4.

[0014] Preferably, the third protrusion is arranged in the middle of the current collector plate, and the second protrusion is arranged in multiple, and the multiple second protrusions are arranged at intervals around the circumferential direction of the third protrusion.

[0015] The second aspect of the present application provides a battery cell comprising the current collector plate of any one of the above technical solutions.

[0016] Compared with the prior art, the present application has the following advantages:

[0017] The circumferential edge of the current collector plate of the present application forms a first protrusion protruding towards the outside of the battery cell, and the first protrusion is connected with the shell of the battery cell, so as to prevent the welding slag from splashing into the inside of the battery cell when the current collector plate and the shell of the battery cell are welded, thereby causing short circuit or large self-discharge of the battery and other adverse conditions; the side of the current collector plate facing the inside of the battery cell forms a protruding connecting part, and a communication hole penetrating the current collector plate is formed on the connecting part for the electrolyte to pass through. The connecting part comprises a second protrusion and a third protrusion arranged at intervals, and the second protrusion is crimped on the tab of the pole group, so as to reduce the contact area of the current collector plate and the tab, ensure the tab and the current collector plate to be pressed tightly, help the welding connection, improve the welding defects such as virtual welding, and improve the welding yield; the third protrusion extends into the through hole on the pole group, which can prevent the problem of blockage or reduction of the exhaust passage in the battery cell caused by the loose pole piece to a certain extent, thereby improving the product quality of the battery cell and ensuring the safety performance of the use performance of the battery cell.

[0018] In order to make the above objectives, characteristics and advantages of the present application more apparent, the following will describe a preferred embodiment in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to make the above objectives, characteristics and advantages of the present application more apparent, the following will describe a preferred embodiment in detail with reference to the accompanying drawings.

[0020] Figure 1 A structure schematic diagram of the current collecting plate provided by the embodiment of the present application is shown in the figure.

[0021] Figure 2 A structure schematic diagram of the current collecting plate provided by the embodiment of the present application is shown in the figure.

[0022] Figure 3 A structure schematic diagram of the current collecting plate provided by the embodiment of the present application is shown in the figure.

[0023] Figure 4 A structure schematic diagram of the current collecting plate provided by the embodiment of the present application is shown in the figure. Figure 3 A structure schematic diagram of the current collecting plate provided by the embodiment of the present application is shown in the figure.

[0024] Figure 5 A structure schematic diagram of the current collecting plate provided by the embodiment of the present application is shown in the figure.

[0025] Figure 6 A structure schematic diagram of the current collecting plate provided by the embodiment of the present application is shown in the figure.

[0026] Figure legend: 10-current collecting plate; 11-first protrusion; 12-connection part; 121-second protrusion; 122-third protrusion; 100-communication hole; 101-first communication hole; 102-second communication hole; 20-pole group; 21-through hole; 30-liquid injection hole. DETAILED DESCRIPTION

[0027] The following detailed description is provided to help the reader obtain a complete understanding of the methods, devices and / or systems described herein. However, various changes, modifications and equivalents can be apparent to those skilled in the art after understanding the disclosure of the present application. For example, the order of the operations described herein is merely an example, and is not limited to the order set forth herein, except for the operations that must occur in a specific order, and changes that will be apparent to those skilled in the art after understanding the disclosure of the present application can be made. In addition, the description of features known in the art can be omitted in order to improve clarity and brevity.

[0028] The features described can be implemented in different forms and are not to be construed as limited to the examples described herein. Rather, these examples have been provided so that this disclosure will be thorough and complete, and will fully convey the scope of the methods, apparatus and / or systems encompassed by the application to those skilled in the art.

[0029] Throughout the specification, when an element (such as a layer, region or substrate) is referred to as being "on" another element, "connected to" another element, "coupled to" another element, "adjacent to" another element, "on top of" another element, or "covering" another element, it can be directly on, connected to, coupled to, adjacent to, on top of, or covering the other element, or one or more other elements can be interposed therebetween. In contrast, when an element is referred to as being "directly on", "directly connected to", "directly coupled to", "directly adjacent to", "directly on top of", or "directly covering" another element, there are no other elements interposed therebetween.

[0030] As used herein, the term "and / or" includes any one of the listed items and any combination of any two or more of the listed items.

[0031] Although terms such as "first", "second", and "third" can be used herein to describe various members, components, regions, layers or portions, these members, components, regions, layers or portions are not limited by these terms. Rather, these terms are only used to distinguish one member, component, region, layer or portion from another member, component, region, layer or portion. Thus, the first member, component, region, layer or portion described in the examples described herein could also be termed a second member, component, region, layer or portion, without departing from the teachings of the examples.

[0032] For ease of description, spatial relationship terms, such as "on", "upper", "beneath", and "lower", can be used herein to describe the relationship between one element and another element as shown in the drawings. Such spatial relationship terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, if the device in the drawings is turned over, the element described as being on "top" of or "beneath" other elements would then be oriented "under" or "over" the other elements, respectively. Thus, the term "on" encompasses both an "on" and an "under" orientation depending on the spatial orientation of the device. The device can be oriented in other ways (e.g., rotated 90 degrees or at other orientations) and the spatial relationship terms used herein are interpreted accordingly.

[0033] The terminology used herein is for the purpose of describing various examples only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "includes," "including" and "has" are inclusive and allow for

[0034] Variations in the shapes illustrated in the drawings can occur as a result of manufacturing processes and / or tolerances. Thus, the examples described herein are not limited to the specific shapes illustrated in the drawings, but include variations in shapes that occur as a result of manufacturing processes and / or tolerances.

[0035] Features of the examples described herein can be combined with one another in a variety of ways. Furthermore, although the examples described herein have a variety of configurations, other configurations are possible.

[0036] According to a first aspect of the present application, there is provided a current collector plate.

[0037] Hereinafter, the specific structure of the current collector plate according to the present embodiment will be described.

[0038] In the present embodiment, as shown in Figures 1 to 4 The current collector plate 10 is formed as a plate-like or sheet-like structure as a whole, and a circumferential edge of the current collector plate 10 is formed with a first protrusion 11 protruding toward the outside of the battery cell, the first protrusion 11 being connected to the battery cell case, so as to increase the thickness dimension of the circumferential edge of the current collector plate 10, thereby preventing the splashing of welding slag into the battery cell when the current collector plate 10 is welded to the battery cell case, and thus preventing short circuit or large self-discharge of the battery cell.

[0039] Specifically, the first protrusion 11 is formed as a closed ring-like structure, and the shape of the first protrusion 11 is the same as the shape of the outer edge of the current collector plate 10. For example, when the current collector plate 10 is formed as a circular plate-like or sheet-like structure, the first protrusion 11 is correspondingly formed as a circular ring-like structure.

[0040] It should be noted that the battery cell case is provided with a liquid injection hole 30 for injecting electrolyte into the battery cell, and the battery cell case includes a battery cell case body in which a cavity for accommodating the electrode group 20 is formed, and a battery cell cover plate capable of closing the cavity, and the first protrusion 11 can be welded to the battery cell case body, and the liquid injection hole 30 can be formed as a through-hole structure penetrating the battery cell cover plate, as described below. It should be further noted that the radial direction of the battery cell is the horizontal direction in the perspective view, and the axial direction of the battery cell is the vertical direction in the perspective view. Figure 4 The radial direction of the battery cell is the horizontal direction in the perspective view, and the axial direction of the battery cell is the vertical direction in the perspective view. Figure 4 The radial direction of the battery cell is the horizontal direction in the perspective view, and the axial direction of the battery cell is the vertical direction in the perspective view.

[0041] In the embodiment, as shown in Figures 1 to 4 The connecting portion 12 is formed on the side of the current collector plate 10 facing the inside of the battery cell. The connecting portion 12 can be formed on the current collector plate 10 by a stamping process. However, the connecting portion 12 is not limited to being formed by a stamping process, and can also be formed by welding or other processing methods, as long as the connecting portion 12 can be formed on the surface of the current collector plate 10 facing the inside of the battery cell. The connecting portion 12 is provided with a communication hole 100 penetrating the current collector plate 10, so that the electrolyte can pass through.

[0042] Specifically, as shown in Figures 1 to 5 The connecting portion 12 includes a second protrusion 121 and a third protrusion 122 arranged at intervals, that is, the second protrusion 121 and the third protrusion 122 do not contact each other in the axial and radial directions of the battery cell. The second protrusion 121 is crimped on the tab of the electrode group 20, thereby reducing the contact area of the current collector plate 10 and the tab, ensuring that the tab is tightly pressed against the current collector plate 10, which helps to improve the welding connection and reduce welding defects such as virtual welding, thereby improving the welding yield and the product quality of the battery cell, and ensuring the use performance of the battery cell.

[0043] In the embodiment, the axis of the through hole 21 in the electrode group 20 is coaxial with the central axis of the electrode group 20, and the through hole 21 penetrates the body of the electrode group 20.

[0044] Further, in the embodiment, as shown in Figures 1 to 3 The third protrusion 122 is arranged in the middle of the current collector plate 10, so that the third protrusion 122 can extend into the through hole 21 in the electrode group 20. Preferably, a plurality of second protrusions 121 are arranged at intervals around the circumference of the third protrusion 122, so that the second protrusions 121 can uniformly press the tab. When the current collector plate 10 is a circular plate structure, each second protrusion 121 can be formed in a fan ring structure.

[0045] In the embodiment, as shown in Figures 1 to 4 The communication hole 100 includes a first communication hole 101 formed on the second protrusion 121 and a second communication hole 102 formed on the third protrusion 122. The first communication hole 101 is shown in the shaded area of the fan ring in Figure 3 The second communication hole 102 is shown in the shaded area of the fan ring in Figure 3The shadow area shown in the middle of the third protrusion 122, so that the third protrusion 122 is formed into a tubular structure, after the liquid injection hole 30 enters the inside of the battery cell from the outside of the battery cell after the battery cell is assembled, it can penetrate the first communication hole 101 or the second communication hole 102 to infiltrate the pole group 20, improve the infiltration speed, and avoid the liquid overflow caused by the accumulation of electrolyte.

[0046] In this embodiment, the liquid injection hole 30, the second communication hole 102 on the second protrusion 121 and the through hole 21 on the pole group 20 are coaxially arranged, which improves the reliability of the electrolyte infiltrating the pole group 20.

[0047] In this embodiment, as shown in Figure 5 , the area of the liquid injection hole 30 is S, with the unit of mm 2 , that is Figure 5 , the area of the hole wall of the circular liquid injection hole 30 is S; the total area of the communication hole 100 is S1, with the unit of mm 2 , that is Figure 3 , the total area of the shadow area is S1, 1≤S1 / S≤5, so as to avoid the decrease of the injection efficiency and the infiltration speed of the pole group 20 caused by the too small parameter of S1 / S, which may cause the liquid overflow; also avoid the increase of the risk of the welding slag falling into the inside of the battery cell caused by the too large parameter of S1 / S.

[0048] Further, in this embodiment, as shown in Figure 3 , the circumferential edge of the projection of the current collector plate 10 on the plane perpendicular to the axis of the through hole 21 encloses an area with an area of S11, with the unit of mm 2 ; in Figure 3 the perspective view, the outermost edge of the current collector plate 10 encloses an area of S11, that is, the area enclosed by the outer side ring wall of the first protrusion 11 is S11. The total area of the projection of the second protrusion 121 on the plane perpendicular to the axis of the through hole 21 is S12, with the unit of mm 2 , that is, the total area of the part of the second protrusion 121 except the first communication hole 101, see Figure 3 , the sum of the areas of all the second protrusions 121 except the first communication hole 101 shown in the shadow part is S12; 30%≤S12 / S11≤80%, so as to avoid the influence of the welding area of the tab and the current collector plate 10 caused by the too small parameter of S12 / S11, thereby affecting the overcurrent; also avoid the problem of the increased risk of the welding defects such as false welding caused by the too large parameter of S12 / S11, which causes the large contact area of the current collector plate 10 and the tab.

[0049] The reliability of the 30%≤S12 / S11≤80% limitation condition in the present application is verified by a plurality of battery cell assembly tests. In each test, a plurality of battery cells of the same size are assembled, and the test results are shown in Table 1.

[0050] Table 1

[0051]

[0052] The reliability of the 1≤S1 / S≤5 limitation condition in the application is verified by assembling multiple groups of battery cells, and the test results are shown in Table 2.

[0053] Table 2

[0054]

[0055] In this embodiment, as shown in Figure 4 and Figure 6 , the size of the through hole 21 on the pole group 20 in the radial direction of the battery cell is D1, unit: mm; the size of the outer wall of the third protrusion 122 in the radial direction of the battery cell is D2, unit: mm; 50%≤D2 / D1≤85%, so as to avoid the problem that the exhaust passage area is small due to the too small parameter of D2 / D1, which is not conducive to exhaust; also avoid the problem that the assembly is difficult and the tab is easily damaged due to the too large parameter of D2 / D1.

[0056] The reliability of the 50%≤D2 / D1≤85% limitation condition in the application is verified by assembling multiple groups of battery cells, and the test results are shown in Table 3.

[0057] Table 3

[0058]

[0059] In this embodiment, as shown in Figure 4 and Figure 6 , the distance between the end of the second protrusion 121 facing the inside of the battery cell and the end of the third protrusion 122 facing the inside of the battery cell is L, unit: mm; the height size of the pole group 20 in the axial direction of the battery cell is L1, unit: mm; 5%≤L / L1≤10%, so as to avoid the problem that the pole piece cannot be reliably supported without loosening due to the too small parameter of L / L1; also avoid the problem that the material cost increases due to the too large parameter of L / L1.

[0060] The reliability of the 5%≤L / L1≤10% limitation condition in the application is verified by assembling multiple groups of battery cells, and the test results are shown in Table 4.

[0061] Table 4

[0062]

[0063] In this embodiment, as shown in Figure 4As shown, the height dimension of the second protrusion 121 in the axial direction of the battery cell is H, that is, in the axial direction of the battery cell, the distance between the side of the second protrusion 121 facing the inside of the battery cell and the side of the main body of the current collector 10 facing the inside of the battery cell is H, and the unit is mm; in the axial direction of the battery cell, the thickness dimension of the current collector 10 is T, and the unit is 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, so as to ensure that the second protrusion 121 is reliably pressed against the tab, and also to avoid excessive occupation of the space in the axial direction of the battery cell to affect the energy density of the battery cell.

[0064] The reliability of the 0.5≤H / T≤4 limitation condition in the application is verified by assembling tests of multiple battery cells, and multiple battery cells of the same size are assembled in each test, and the test results are shown in Table 5.

[0065] Table 5

[0066]

[0067] According to the application, the circumferential edge of the current collector is formed with a first protrusion protruding towards the outside of the battery cell, and the first protrusion is connected with the battery cell shell, so as to prevent the welding slag from splashing into the battery cell when the current collector is welded with the battery cell shell, thereby causing short circuit or large self-discharge of the battery and other adverse conditions; the side of the current collector facing the inside of the battery cell is formed with a protruding connecting portion, and a communication hole penetrating through the current collector is formed in the connecting portion to allow the electrolyte to pass through. The connecting portion includes a second protrusion and a third protrusion arranged at intervals, the second protrusion is pressed against the tab on the pole group, so as to reduce the contact area of the current collector and the tab, ensure the pressing of the tab and the current collector, help the welding connection, improve the welding defects such as false welding, and improve the welding yield; the third protrusion extends into the through hole on the pole group, which can prevent the problem of blockage or reduction of the exhaust passage in the battery cell caused by loose pole pieces to some extent, thereby improving the product quality of the battery cell and ensuring the safety performance of the use performance of the battery cell.

[0068] According to the application, the battery cell includes the current collector as described above, and thus has all the beneficial effects described above, which will not be repeated here.

[0069] Finally, it should be noted that the above-described embodiments are merely specific embodiments of the present application, which are used to illustrate the technical solutions of the present application, but not to limit the same. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that any skilled person in the art can still modify or easily think of changes to the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some of the technical features, within the technical scope disclosed by the present application. The modifications, changes or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to 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 collector plate according to any one of claims 1 to 7.

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