Bottom supporting plate structure and battery cell

Abstract

The invention relates to the technical field of batteries, in particular to a bottom supporting plate structure and a battery cell. According to the bottom supporting plate structure, a plurality of positioning holes are formed in a bottom supporting plate body, and at least two positioning holes are distributed in the bottom supporting plate body at intervals in the first direction, so that the positioning tool can position the bottom supporting plate structure, and the assembling quality of the bottom supporting plate structure and an insulating film is improved; the distance between the centers of the two adjacent positioning holes in the first direction is W, and the unit is mm; the size of the bottom supporting plate main body in the first direction is W0, and the unit is mm; 0.65 < = W / W < = 0.9. The positioning reliability of the bottom supporting plate structure can be improved, the insulation performance can be guaranteed, the bottom supporting plate structure and an insulation film are accurately positioned after hot melting, it is guaranteed that the bottom supporting plate structure and the insulation film can enter a shell smoothly after film coating, and therefore the yield of battery cells is improved.

Description

Technical Field

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

[0002] Lithium-ion batteries are widely used in various fields such as transportation power supplies, power storage, new energy storage power supplies, and aerospace and military industries due to their advantages such as large capacity, high operating voltage, strong charge retention, and long cycle life. In prismatic cells, the top of the electrode assembly is connected to the terminal post on the cover plate via a tab. The circumferential sidewalls and bottom of the electrode assembly are covered with an insulating film. A bottom support plate is located on one side of the bottom of the electrode assembly to isolate the internal electrode assembly from the battery casing. Currently, the bottom support plate and insulating film are difficult to assemble and position in prismatic cells. Deviations in the position of the bottom support plate after coating can affect the insertion into the casing, leading to a decrease in the cell yield. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a bottom plate structure and a battery cell to solve the problem that the assembly and positioning of the bottom plate and insulating film in the battery cell is difficult, and the deviation between the position of the electrode assembly and the bottom plate after coating will affect the casing and lead to a decrease in the yield of the battery cell.

[0004] The first aspect of the present invention provides a base plate structure, comprising: Base plate main body; Positioning holes are formed on the base plate body. Multiple positioning holes are provided, and at least two positioning holes are arranged at intervals on the base plate body along a first direction. In the first direction, the distance between the centers of two adjacent positioning holes is W, in mm; the dimension of the base plate body in the first direction is W0, in mm; 0.65≤W / W0≤0.9.

[0005] Preferably, the base plate body is formed as a strip-shaped plate structure extending along the second direction, and the first direction, the second direction and the thickness direction of the base plate body are arranged perpendicular to each other.

[0006] Preferably, 65mm≤W0≤580mm.

[0007] Preferably, at least two of the positioning holes are arranged at intervals along the second direction on the base plate body; In the second direction, the distance between the centers of two adjacent positioning holes is L, in mm; the dimension of the base plate body in the second direction is L0, in mm; 0.7≤L / L0≤0.95.

[0008] Preferably, 12mm≤L0≤80mm.

[0009] Preferably, the positioning pin on the positioning fixture can extend into the positioning hole, and the shape of the positioning hole is the same as the cross-sectional shape of the positioning pin perpendicular to the direction in which it extends into the positioning hole.

[0010] Preferably, the projected area of ​​each positioning hole on a plane parallel to the base plate body is S = 4 mm. 2 ≤S≤80mm 2 .

[0011] Preferably, the base plate body is formed into a rectangular plate structure, and four positioning holes are provided, which are respectively located at the four corners of the base plate body.

[0012] Preferably, the base plate body has a flow guide hole, which is located in the middle of the base plate body, and a plurality of positioning holes are arranged around the area where the flow guide hole is located.

[0013] A second aspect of the present invention provides a battery cell comprising the base plate structure described in any of the above technical solutions.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: In this invention, the positioning holes in the base plate structure are formed on the base plate body. Multiple positioning holes are provided, with at least two holes spaced apart along a first direction on the base plate body. This allows the positioning fixture to position the base plate structure, improving the assembly quality of the base plate structure and the insulating film. The distance between the centers of two adjacent positioning holes in the first direction is W (in mm). The dimension of the base plate body in the first direction is W0 (in mm). 0.65 ≤ W / W0 ≤ 0.9. This improves the positioning reliability of the base plate structure and ensures insulation performance, avoiding poor insulation due to an excessively large W / W0 parameter, and also avoiding poor positioning accuracy due to a deflection of the base plate structure on the positioning fixture caused by an excessively small W / W0 parameter. This ensures accurate positioning of the base plate structure and the insulating film after heat fusion, ensuring smooth insertion into the casing after coating, thereby improving the yield rate of the battery cell.

[0015] 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

[0016] 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.

[0017] Figure 1 This is a schematic diagram of the base plate structure provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the base plate structure installed on the positioning fixture according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the process of assembling battery cells using the base plate structure provided in an embodiment of the present invention.

[0018] Icons: 10-Base plate body; 11-Positioning hole; 12-Guide hole; 20-Positioning fixture; 21-Positioning pin; 31-Cover plate body; 32-First insulating component; 33-Second insulating component; 34-Pole post; 35-Connector; 40-Insulating film; 50-Pole group; 60-Exhaust pressure relief unit; D1-First direction; D2-Second direction. Detailed Implementation

[0019] 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.

[0020] 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.

[0021] 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.

[0022] As used herein, the term “and / or” includes any one of the relevant items listed and any combination of any two or more items.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] According to a first aspect of the present invention, a base plate structure is provided, which includes a base plate body 10 and a positioning hole 11.

[0029] The specific structure of the base plate structure according to this embodiment will be described below.

[0030] In this embodiment, as Figure 1 and Figure 2 As shown, the base plate body 10 is formed as a plate-like structure, such as... Figure 3 As shown, the base plate structure is mounted on the surface of the insulating film 40 facing away from the electrode group 50, so that the base plate structure is positioned on the outer surface of the insulating film 40 covering the electrode group 50. The positioning hole 11 is formed on the base plate body 10, and the positioning hole 11 can be a through hole or a blind hole.

[0031] Specifically, in this embodiment, multiple positioning holes 11 are provided, of which at least two positioning holes 11 are arranged at intervals along the first direction D1 on the base plate body 10, so that the positioning fixture 20 can reliably position the base plate structure and improve the assembly quality of the base plate structure and the insulating film 40. In the first direction D1, the distance between the centers of two adjacent positioning holes 11 is W, in mm; the dimension of the base plate body 10 in the first direction D1 is W0, in mm; 0.65≤W / W0≤0.9, thus improving the positioning reliability of the base plate structure and ensuring insulation performance, avoiding the problem of tearing and damage at the positioning holes 11 due to insufficient insulation strength at the edge of the base plate structure caused by an excessively large W / W0 parameter, resulting in poor insulation; it also avoids the problem of the base plate structure being skewed or deflected on the positioning fixture 20 due to an excessively small W / W0 parameter, which makes it easy for it to shift after being heat-fused with the insulating film 40, thereby ensuring accurate positioning of the base plate structure and the insulating film 40 after heat fusion, ensuring smooth insertion into the casing after coating, and thus improving the yield of the battery cell.

[0032] Preferably, such as Figure 1 As shown, 65mm≤W0≤580mm.

[0033] Furthermore, in this embodiment, as Figure 1 As shown, the base plate body 10 is formed as a strip-shaped plate structure extending along the second direction D2. The first direction D1, the second direction D2 and the thickness direction of the base plate body 10 are arranged perpendicularly to each other. For example, the base plate body 10 is formed as a rectangular plate structure, where the first direction D1 is the length direction of the rectangle and the second direction D2 is the width direction of the rectangle.

[0034] In a preferred embodiment, such as Figure 1As shown, at least two positioning holes 11 are spaced apart on the base plate body 10 along the second direction D2; the distance between the centers of two adjacent positioning holes 11 in the second direction D2 is L, in mm; the dimension of the base plate body 10 in the second direction D2 is L0, in mm; 0.7≤L / L0≤0.95, thus further improving the positioning accuracy and reliability of the base plate structure and the insulating film 40, avoiding the situation where the base plate body 10 bulges in the middle position in the second direction D2 due to the L / L0 dimension being too large, making it impossible to install with the insulating film 40, and also further avoiding the situation where the positioning accuracy is poor due to the L / L0 dimension being too small, which easily causes the base plate structure to deflect or tilt after installation; thereby further improving the effectiveness of positioning.

[0035] Preferably, 12mm≤L0≤80mm.

[0036] Preferably, such as Figure 2 As shown, the positioning hole 11 is a through hole, through which the positioning pin 21 on the positioning fixture 20 passes.

[0037] In a preferred embodiment, such as Figures 1 to 3 As shown, the base plate body 10 is formed into a rectangular plate structure, and four positioning holes 11 are selectively provided. The four positioning holes 11 are respectively located at the four corners of the base plate body 10, so as to improve the positioning reliability while ensuring the structural strength of the base plate body 10 and reduce the risk of the base plate structure deflection and skew.

[0038] As described above, the positioning hole 11 is preferably a through hole structure, such as... Figure 2 As shown, the positioning pins 21 on the positioning fixture 20 are arranged in a one-to-one correspondence with the positioning holes 11. The positioning pins 21 on the positioning fixture 20 can extend into the positioning holes 11. The shape of the positioning hole 11 is the same as the cross-sectional shape of the positioning pin 21 perpendicular to the direction in which it extends into the positioning hole 11. For example, if the positioning hole 11 is a circular hole, the part of the positioning pin 21 that is positioned and cooperates with the positioning hole 11 is formed into a cylindrical structure.

[0039] Furthermore, the top of the positioning pin 21 is formed into a conical or frustum structure to facilitate the positioning pin 21 to extend into the positioning hole 11 and improve assembly efficiency.

[0040] Preferably, in this embodiment, the projected area of ​​each positioning hole 11 on a plane parallel to the base plate body 10 is S, 4mm. 2 ≤S≤80mm 2 This avoids the reduction in insulation performance and positioning accuracy due to an excessively large size of S, and also avoids the difficulty in assembling the positioning pin 21 with the positioning hole 11 due to an excessively small size of S.

[0041] Furthermore, in this embodiment, such as Figures 1 to 3As shown, the bottom support plate body 10 is provided with a flow guide hole 12. The flow guide hole 12 is a through hole structure that runs through the thickness direction of the bottom support plate body 10 to meet the requirement that the fluid in the battery cell passes through the bottom support plate body 10. Multiple flow guide holes 12 are provided and arranged in an array on the bottom support plate body 10.

[0042] Preferably, the flow guide hole 12 is located in the middle of the base plate body 10, and a plurality of positioning holes 11 are arranged around the area where the flow guide hole 12 is provided. This ensures that the fluid can pass through the flow guide hole 12 while making the structural strength and insulation performance of the base plate body 10 reliable.

[0043] In addition, the battery cell formed by assembling the base plate structure includes, in addition to the insulating film 40 and electrode group 50 as described above, a cover plate assembly, an exhaust pressure relief unit 60, and a housing assembled with the cover plate assembly.

[0044] like Figure 3 As shown, the cover plate assembly includes a cover plate body 31, a first insulating member 32, a second insulating member 33, a pole post 34, and a connector 35. The cover plate body 31 is formed as a sheet or plate structure, and its surface has through holes for assembling the pole post 34. After the pole post 34 is assembled with the cover plate body 31, one axial end of the pole post 34 extends to the side of the cover plate body 31 facing the outside of the battery cell. The connector 35 is formed as an annular block structure, which is riveted and / or welded to the end of the pole post 34 extending to the outside of the cover plate body 31 facing the outside of the battery cell. The first insulating member 32 is sandwiched between the side of the cover plate body 31 facing the outside of the battery cell and the connector 35. The other axial end of the pole post 34 is located on the side of the cover plate body 31 facing the inside of the battery cell, and part of the second insulating member 33 is sandwiched between the pole post 34 and the side of the cover plate body 31 facing the inside of the battery cell.

[0045] The tabs on the electrode group 50 are connected to the base plate on the electrode post 34 located inside the cell.

[0046] In this embodiment, the exhaust pressure relief unit 60 can be an exhaust valve. The cover plate body 31 has a through hole for installing the exhaust pressure relief unit 60. When the gas generated inside the battery cell reaches the preset pressure, the exhaust valve opens to allow the gas inside the battery cell to be discharged. The exhaust pressure relief unit 60 can also be an explosion-proof groove engraved on the cover plate body 31. This reduces the thickness of a local area of ​​the cover plate body 31, so that the explosion-proof groove can be broken through under the pressure inside the battery cell.

[0047] The cover plate assembly also includes a seal (not shown in the figure). The seal can be an annular sealing ring. The seal is sleeved on the pole post 34, and part of the seal is pressed against the bottom plate on the cover plate body 31 and the pole post 34 located inside the cell, and / or part of the seal is pressed against the first insulating member 32 and the bottom plate on the pole post 34 located inside the cell, so as to ensure the sealing performance of the cover plate assembly.

[0048] The following tests were conducted by assembling base plate structures with different dimensional parameters into battery cells to verify the reliability of the above-mentioned limits of 0.65≤W / W0≤0.9 and 0.7≤L / L0≤0.95. The test results and analysis are shown in Table 1.

[0049] Table 1

[0050] According to the present invention, a positioning hole 11 is formed on the base plate body 10 in a base plate structure. Multiple positioning holes 11 are provided, with at least two positioning holes 11 spaced apart along the first direction D1 on the base plate body 10. This allows the positioning fixture 20 to position the base plate structure, improving its assembly quality with the insulating film 40. The distance between the centers of two adjacent positioning holes 11 in the first direction D1 is W (in mm). The dimension of the base plate body 10 in the first direction D1 is W0 (in mm). 0.65 ≤ W / W0 ≤ 0.9. This improves the positioning reliability of the base plate structure and ensures insulation performance, avoiding poor insulation due to an excessively large W / W0 parameter, and also avoiding poor positioning accuracy due to a deflection of the base plate structure on the positioning fixture 20 caused by an excessively small W / W0 parameter. This ensures accurate positioning of the base plate structure and the insulating film 40 after heat fusion, ensuring smooth insertion into the casing after coating, thereby improving the yield rate of the battery cell.

[0051] The battery cell provided by the present invention includes the bottom support plate structure as described above, and thus has all the above-mentioned beneficial effects, which will not be repeated here.

[0052] 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 base plate structure, characterized in that, include: Base plate main body; Positioning holes are formed on the base plate body. Multiple positioning holes are provided, and at least two positioning holes are arranged at intervals on the base plate body along a first direction. In the first direction, the distance between the centers of two adjacent positioning holes is W, in mm; The dimension of the base plate body in the first direction is W0, in mm; 0.65≤W / W0≤0.

9.

2. The base plate structure according to claim 1, characterized in that, The base plate body is formed as a strip-shaped plate structure extending along the second direction, and the first direction, the second direction and the thickness direction of the base plate body are arranged perpendicular to each other.

3. The base plate structure according to claim 1, characterized in that, 65mm≤W0≤580mm.

4. The base plate structure according to claim 1, characterized in that, At least two of the positioning holes are arranged at intervals along the second direction on the base plate body; In the second direction, the distance between the centers of two adjacent positioning holes is L, in mm; The dimension of the base plate body in the second direction is L0, in mm; 0.7≤L / L0≤0.

95.

5. The base plate structure according to claim 4, characterized in that, 12mm≤L0≤80mm.

6. The base plate structure according to claim 1, characterized in that, The positioning pin on the positioning fixture can extend into the positioning hole, and the shape of the positioning hole is the same as the cross-sectional shape of the positioning pin perpendicular to the direction in which it extends into the positioning hole.

7. The base plate structure according to claim 1, characterized in that, The projected area of ​​each positioning hole on a plane parallel to the base plate body is S, 4mm. 2 ≤S≤80mm 2 .

8. The base plate structure according to claim 1, characterized in that, The base plate body is formed into a rectangular plate structure, and four positioning holes are provided, which are respectively located at the four corners of the base plate body.

9. The base plate structure according to claim 1, characterized in that, The base plate body has a flow guide hole, which is located in the middle of the base plate body, and a plurality of positioning holes are arranged around the area where the flow guide hole is located.

10. A battery cell, characterized in that, The base plate structure includes any one of claims 1 to 9.

Images