Insulation structure and battery cell

Abstract

The invention relates to the technical field of batteries, in particular to an insulation structure and a battery cell. A first through hole is formed in the insulation structure, and a first windowing part used for showing a nickel sheet welding area and a second windowing part used for showing a pressure relief area are formed in the first through hole; the size of the nickel sheet welding area in the first direction is A1, the size of the first windowing part in the first direction is A2, and A2-A1 is larger than or equal to 3.5 mm and smaller than or equal to 4.5 mm; and the size of the pressure relief area in the first direction is B1, the size of the second windowing part in the first direction is B2, and 0.2 mm < = B2-B1 < = 0.4 mm. According to the invention, the windowing size range of the first windowing part and the second windowing part is limited, so that the welding effect of the nickel sheet and smooth exhaust and pressure relief when the battery cell fails are ensured, the influence of overlarge windowing size on the adhesion area of the insulation structure and the battery cell cover plate is avoided, the risk of warping and falling off of the insulation structure is reduced, and the reliability of the battery cell is improved. And firm assembly of the insulation structure and the cell cover plate is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to an insulating structure and an electric core. Background Art

[0002] The structure of a lithium-ion battery consists of a cover plate, a housing, an electrode group, an electrolyte, an internal and external insulating structure, etc. The external insulation of the housing generally adopts methods such as spraying insulating materials and wrapping insulating tapes. The cover plate generally achieves insulation by pasting an insulating top cover patch. In order to cooperate with improving the energy density of the whole battery pack, the thickness of a single electric core is made thinner and thinner, making the size of the top cover narrower and narrower. In addition, with the continuous optimization of the whole pack design, in addition to the conventional pole columns, explosion-proof valves, liquid injection holes, etc. on the electric core cover plate, a temperature sensor acquisition area, a nickel sheet welding voltage acquisition area, etc. are successively added, resulting in a gradual increase in the opening area of the top cover patch of the cover plate, thus causing the effective area of the paste between the top cover patch and the cover plate to become smaller and smaller, making the top cover patch warp and fall off after assembly, and unable to ensure the insulation performance of the electric core. Summary of the Invention

[0003] In view of this, the purpose of the present application is to provide an insulating structure and an electric core to solve the problem that the effective paste area between the existing top cover patch and the electric core cover plate is small, and the top cover patch warps and falls off after assembly, and the insulation performance of the electric core cannot be ensured.

[0004] The first aspect of the present invention provides an insulating structure, which is pasted on the outer surface of an electric core cover plate. A nickel sheet welding area and a pressure relief area are provided on the electric core cover plate. Among them, a first through hole is formed in the insulating structure, and a first window part and a second window part are formed in the first through hole. The first window part is used to show the nickel sheet welding area, and the second window part is used to show the pressure relief area;

[0005] The size of the nickel sheet welding area in the first direction is A1, the size of the first window part in the first direction is A2, and 3.5 mm ≤ A2 - A1 ≤ 4.5 mm;

[0006] The size of the pressure relief area in the first direction is B1, the size of the second window part in the first direction is B2, and 0.2 mm ≤ B2 - B1 ≤ 0.4 mm.

[0007] Preferably, A2 ≠ B2.

[0008] Preferably, the first window part and the second window part are arranged at intervals, and / or a transition part is arranged between the first window part and the second window part.

[0009] Preferably, 2 mm ≤ │A2 - B2│ ≤ 6 mm.

[0010] Preferably, the cover body of the cell cover plate is a rectangular plate-like structure, and the first direction is the width direction of the cover body.

[0011] Preferably, the first window portion and the second window portion are arranged at intervals along the length direction of the cover body.

[0012] Preferably, a second through hole is further formed in the insulating structure for the protruding pole assembly on the cell cover plate to extend out.

[0013] Preferably, the minimum distance between the first through hole and / or the second through hole and the edge of the insulating structure is C, and C≥2mm.

[0014] Preferably, a pressure relief assembly is installed in the pressure relief area. The pressure relief assembly includes a pressure relief member and a protection member arranged on the side of the pressure relief member facing the outside of the cell. B1 is the dimension of the protection member in the first direction.

[0015] In a second aspect of the present invention, a cell is provided, including the insulating structure described in any one of the above technical solutions.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] A first through hole is formed in the insulating structure of the present invention. A first window portion is formed in the first through hole for showing the nickel sheet welding area and a second window portion for showing the pressure relief area. The dimension of the nickel sheet welding area in the first direction is A1, and the dimension of the first window portion in the first direction is A2, and 3.5mm≤A2 - A1≤4.5mm. In this way, it is avoided that the window size is too small to cause insufficient space for welding the nickel sheet, thereby ensuring the welding effect of the nickel sheet. It also avoids that the window size is too large to affect the bonding area between the insulating structure and the cell cover plate, and realizes the risk of reducing the warping and falling off of the insulating structure. The dimension of the pressure relief area in the first direction is B1, and the dimension of the second window portion in the first direction is B2, and 0.2mm≤B2 - B1≤0.4mm. In this way, it is avoided that the window size is too small to affect the exhaust pressure relief when the cell fails, thereby ensuring the safety performance of the cell. It also avoids that the window size is too large to cause insufficient bonding area between the insulating structure and the cell cover plate, thereby ensuring the firm assembly of the insulating structure and the cell cover plate.

[0018] To make the above objects, features, and advantages of the present application more obvious and understandable, the following specific preferred embodiments are given in conjunction with the accompanying drawings and described in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1 Explosion structure diagram of the assembly of the insulation structure and the cell cover plate provided by the embodiment of the present invention;

[0021] Figure 2 Assembly structure diagram of the insulation structure and the cell cover plate provided by the embodiment of the present invention;

[0022] Figure 3 For Figure 2 Enlarged structure diagram at position M in

[0023] Figure 4 Structure diagram of the insulation structure provided by the embodiment of the present invention, where the distance from the first through hole to the edge is dimension C;

[0024] Figure 5 Structure diagram of the insulation structure provided by the embodiment of the present invention, where the distance from the second through hole to the edge is dimension C.

[0025] Icon: 10 - Insulation structure; 11 - First through hole; 111 - First windowing part; 112 - Second windowing part; 113 - Transition part; 12 - Second through hole; 201 - Nickel sheet welding area; 202 - Pressure relief area; 21 - Cover plate main body; 211 - Exhaust hole; 22 - Terminal assembly; 221 - Terminal; 222 - Riveting part; 223 - Insulating part; 231 - Pressure relief part; 232 - Protective part; D1 - First direction. Specific embodiments

[0026] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the methods, devices, and / or systems described herein. However, after understanding the disclosure of the present application, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be obvious. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein, but rather, changes that will be obvious after understanding the disclosure of the present application can be made, except for operations that must occur in a specific order. In addition, descriptions of features known in the art may be omitted for the sake of clarity and conciseness.

[0027] The features described herein can be implemented in various forms and should not be construed as limited to the examples described herein. Rather, the examples described herein are provided only to illustrate some of the many possible ways of implementing the methods, devices, and / or systems described herein that will be apparent after understanding the disclosure of the present application.

[0028] Throughout the specification, when an element (such as a layer, region, or substrate) is described as "on" another element, "connected to" another element, "coupled to" another element, "above" another element, or "covering" another element, it can be directly "on" another element, "connected to" another element, "coupled to" another element, "above" another element, or "covering" another element, or there can be one or more other elements intervening between them. In contrast, when an element is described as "directly on" another element, "directly connected to" another element, "directly coupled to" another element, "directly above" another element, or "directly covering" another element, there can be no other elements intervening between them.

[0029] As used herein, the term "and / or" includes any one of the listed related items and any combination of any two or more of them.

[0030] Although terms such as "first", "second", and "third" may be used herein to describe various components, elements, regions, layers, or parts, these components, elements, regions, layers, or parts are not limited by these terms. Rather, these terms are only used to distinguish one component, element, region, layer, or part from another. Thus, the first component, element, region, layer, or part described in the examples herein may also be referred to as the second component, element, region, layer, or part without departing from the teachings of the examples.

[0031] For ease of description, spatial relationship terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another as shown in the figures. Such spatial relationship terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is flipped, an element described as "above" or "upper" relative to another element will then be "below" or "lower" relative to the other element. Thus, the term "above" includes both the orientations of "above" and "below" 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 relationship terms used herein will be interpreted accordingly.

[0032] The terms used herein are for describing various examples only and are not intended to limit the present disclosure. Unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. The terms "comprising," "including," and "having" enumerate the stated features, quantities, operations, components, elements, and / or combinations thereof that exist, but do not preclude the existence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0033] Due to manufacturing techniques and / or tolerances, variations in the shapes shown in the drawings may occur. Accordingly, the examples described herein are not limited to the specific shapes shown in the drawings, but include changes in shape that occur during manufacturing.

[0034] The features of the examples described herein can be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations are possible, as will be apparent after understanding the disclosure of the present application.

[0035] According to a first aspect of the present invention, an insulating structure is provided.

[0036] Hereinafter, the specific structure of the insulating structure according to the present embodiment will be described.

[0037] In the present embodiment, as Figures 1 to 5 shown, the insulating structure 10 is formed into a sheet-like structure, and its specific shape is adapted to the shape of the cover body 21 in the cell cover. For example, when the cover body 21 is a rectangular plate-like structure, the insulating structure 10 is formed into a rectangular sheet-like structure. For example, when the cover body 21 is formed into a circular plate-like structure, the insulating structure 10 is formed into a circular sheet-like structure. The main body of the insulating structure 10 is made of an insulating material to play an insulating and protective role, and an adhesive layer is provided on the side facing the cell cover, so that the insulating structure 10 can be attached to the outer surface of the cell cover, specifically, the outer surface of the cover body 21.

[0038] In the present embodiment, as Figure 1 and Figure 2 shown, a nickel sheet welding area 201 and a pressure relief area 202 are provided on the cell cover. The nickel sheet welding area 201 is used for welding nickel sheets, and the pressure relief area 202 is used for discharging the gas inside the cell when the cell fails to ensure the safe use of the cell.

[0039] Specifically, as Figure 3As shown, an exhaust hole 211 is formed in the cover plate body 21. The exhaust hole 211 is a through-hole structure penetrating the cover plate body 21, enabling the inside and outside of the battery cell to communicate via the exhaust hole 211. A pressure relief component is installed in the pressure relief area 202. The pressure relief component includes a pressure relief element 231 installed in the exhaust hole 211 and a protection element 232 disposed on the side of the pressure relief element 231 facing the outside of the battery cell. The protection element 232 covers a part of the exhaust hole 211. The pressure relief element 231 can be an explosion-proof valve, and the protection element 232 can be an explosion-proof valve patch to protect the pressure relief element 231, preventing components outside the battery cell from damaging the pressure relief element 231 and causing the pressure relief element 231 to open prematurely, thus unable to ensure the performance of the battery cell.

[0040] In this embodiment, as Figures 1 to 5 shown, a first through-hole 11 is formed in the insulating structure 10. The first through-hole 11 penetrates the insulating structure 10 in the thickness direction of the insulating structure 10. A first window portion 111 and a second window portion 112 are formed in the first through-hole 11. The first window portion 111 and the second window portion 112 are arranged along the radial direction of the first through-hole 11 (i.e., the direction perpendicular to the axial direction of the first through-hole 11). The first window portion 111 is used to expose the nickel sheet welding area 201, that is, the nickel sheet welding area 201 on the battery cell cover plate is exposed from the first window portion 111. The second window portion 112 is used to expose the pressure relief area 202, that is, the pressure relief area 202 on the battery cell cover plate is exposed from the second window portion 112. The size of the nickel sheet welding area 201 in the first direction D1 is A1, and the size of the first window portion 111 in the first direction D1 is A2. 3.5mm ≤ A2 - A1 ≤ 4.5mm. In this way, it is avoided that the window size is too small to cause insufficient space for welding the nickel sheet, thus ensuring the welding effect of the nickel sheet. It also avoids that the window size is too large to affect the bonding area between the insulating structure 10 and the battery cell cover plate, realizing the risk of reducing the warping and falling off of the insulating structure 10. The size of the pressure relief area 202 in the first direction D1 is B1. Specifically, B1 is the size of the protection element 232 in the first direction D1. The size of the second window portion 112 in the first direction D1 is B2. 0.2mm ≤ B2 - B1 ≤ 0.4mm. In this way, it is avoided that the window size is too small to affect the exhaust and pressure relief when the battery cell fails, thus ensuring the safety performance of the battery cell. It also avoids that the window size is too large to cause insufficient bonding area between the insulating structure 10 and the battery cell cover plate, thus ensuring the firm assembly of the insulating structure 10 and the battery cell cover plate. By limiting the window size range of the first window portion 111 and the second window portion 112, the present application ensures the welding effect of the nickel sheet and the smooth exhaust and pressure relief when the battery cell fails, while realizing the risk of reducing the warping and falling off of the insulating structure 10.

[0041] It should be noted that the limitation of the size range of A2 takes into account factors such as the opening tolerance of the first through-hole 11, the alignment accuracy of the equipment for pasting the insulating structure 10, the size of the welding head when welding the nickel sheet, and the tolerance of the welding equipment.

[0042] In this embodiment, as Figure 2 and Figure 3 shown, the protective member 232 and the insulating structure 10 are both disposed on the surface of the cover plate body 21 facing the outside of the battery cell, and a part of the hole wall of the first through hole 11 surrounds at least a part of the circumferential side wall of the protective member 232.

[0043] In this embodiment, as Figure 3 shown, A2≠B2, so that the first through hole 11 is formed into a through hole structure with an irregular shape. In this way, while satisfying the welding effect of the nickel sheet and smoothly exhausting and relieving pressure when the battery cell fails, the effective adhesion area between the insulating structure 10 and the cover plate body 21 is maximally increased, ensuring that the insulating structure 10 is firmly and reliably assembled with the battery cell cover plate.

[0044] Optionally, as Figures 1 to 5 shown, the first window portion 111 is formed into a rectangular through hole structure, and the second window portion 112 is formed into a through hole structure with a rectangular shape at one end close to the first window portion 111 and a semicircular shape at the end far from the first window portion 111.

[0045] Furthermore, in this embodiment, as Figure 2 and Figure 3 shown, the first window portion 111 and the second window portion 112 are arranged at intervals to meet the welding and pressure relief requirements; and / or in a preferred embodiment, a transition portion 113 is provided between the first window portion 111 and the second window portion 112, and the transition portion 113 can be formed into a trapezoidal through hole structure. In this way, the situation of structural mutation at the connection between the first window portion 111 and the second window portion 112 is avoided. While ensuring that the nickel sheet welding is not affected, the contact area between the insulating structure 10 and the cover plate body 21 is also increased, and the mutant corner structure on the insulating structure 10 is reduced, thereby reducing the warping risk.

[0046] In this embodiment, as Figure 3 shown, 2mm≤│A2 - B2│≤6mm to avoid a too large size gap between A2 and B2 resulting in a reduction in the die-cutting yield rate of the first through hole 11.

[0047] In this embodiment, as Figures 1 to 3 shown, the cover plate body 21 of the battery cell cover plate becomes a rectangular plate-like structure, and the first direction D1 is the width direction of the main body, so as to increase the contact area between the insulating structure 10 and the cover plate body 21 in the width direction of the cover plate body 21 to meet the use requirements of battery cells with smaller thickness dimensions and / or battery cell cover plates with narrower widths.

[0048] Furthermore, in this embodiment, as Figures 1 to 3As shown, the first window portion 111 and the second window portion 112 are arranged at intervals along the length direction of the cover plate main body 21, so as to ensure that the insulating structure 10 has a sufficient contact area with the cover plate main body 21 in the width direction of the cover plate main body 21, which is convenient for the assembly of the insulating structure 10 and ensures that the insulating structure 10 is firmly adhered to the cover plate main body 21.

[0049] In addition, in this embodiment, as Figure 1 and Figure 2 shown, the battery cell cover plate further includes a pole column assembly 22 protruding from the cover plate main body 21. The pole group assembly includes a pole column 221, a riveting part 222 and an insulating part 223. A riveting hole is formed in the riveting part 222. The pole column 221 passes through the cover plate main body 21 and the riveting hole and is riveted to the riveting part 222 through a stamping process, so as to fix the pole column 221 on the cover plate main body 21. The insulating part 223 can be made of insulating materials such as PP or PPS to separate the cover plate main body 21 and the pole column 221, thereby reducing the short-circuit risk. Part of the insulating part 223 surrounds the circumferential side wall of the riveting part 222 to improve the insulating protection effect. In this embodiment, the riveting part 222 is formed into a metal block structure. The axes of the riveting hole and the pole column 221 both extend along the thickness direction of the cover plate main body 21. The number of riveting holes on the riveting part 222 can be one or more, and the specific number is set according to the number of pole columns 221.

[0050] Furthermore, in this embodiment, as Figures 1 to 5 shown, a second through hole 12 is further formed in the insulating structure 10 for the protruding pole column assembly 22 on the battery cell cover plate to protrude. The second through hole 12 is a through hole penetrating the insulating structure 10 and has the same shape as the circumferential side wall of the insulating part 223. The pole column assembly 22 passes through the second through hole 12 to ensure that the insulating structure 10 is flatly adhered to the cover plate main body 21.

[0051] The first through hole 11 and the second through hole 12 are formed by die-cutting process. The first through hole 11 and the second through hole 12 are arranged at intervals. In a preferred embodiment, as Figure 4 and Figure 5 shown, the minimum distance between the first through hole 11 and / or the second through hole 12 and the edge of the insulating structure 10 is C, and C≥2mm, so as to ensure the die-cutting yield rate of the insulating structure 10 during production, and if the size of C is too small, it is easy to cause the warping of the insulating structure 10.

[0052] Next, the insulating structure 10 with different A2, B2 and C parameters is assembled with the battery cell cover plate, and the assembly quality of the insulating structure 10 is detected to verify whether the above-mentioned limiting conditions are reliable. In each embodiment, multiple groups of insulating structures 10 and battery cell cover plates with the same size are assembled to ensure the accuracy and reliability of the test results. The test results are shown in the following table.

[0053]

[0054] It should be noted that when welding the nickel sheet, it is necessary to ensure that there is no interference in the insulating structure 10 (that is, there is no situation of pressing the insulating structure 10 under reasonable conditions), and the control of the welding defect rate needs to reach <0.1%.

[0055] According to an insulating structure provided by the present invention, a first through hole is formed in the insulating structure, and a first windowing portion is formed in the first through hole for showing the nickel sheet welding area and a second windowing portion for showing the pressure relief area; the size of the nickel sheet welding area in the first direction is A1, the size of the first windowing portion in the first direction is A2, and 3.5mm ≤ A2 - A1 ≤ 4.5mm. In this way, it is avoided that the windowing size is too small to cause insufficient space for welding the nickel sheet, thus ensuring the welding effect of the nickel sheet, and it is also avoided that the windowing size is too large to affect the bonding area between the insulating structure and the battery cell cover plate, realizing the reduction of the risk of warping and falling off of the insulating structure; the size of the pressure relief area in the first direction is B1, the size of the second windowing portion in the first direction is B2, and 0.2mm ≤ B2 - B1 ≤ 0.4mm. In this way, it is avoided that the windowing size is too small to affect the exhaust pressure relief when the battery cell fails, thus affecting the safety performance of the battery cell, and it is also avoided that the windowing size is too large to cause insufficient bonding area between the insulating structure and the battery cell cover plate, thereby ensuring the firm assembly of the insulating structure and the battery cell cover plate.

[0056] According to a battery cell provided by the present invention, the insulating structure as described above is attached to the battery cell cover plate of the battery cell, while ensuring the welding effect of the nickel sheet and the smooth exhaust pressure relief when the battery cell fails, reducing the risk of warping and falling off of the insulating structure, ensuring the firm assembly of the insulating structure and the battery cell cover plate, thereby improving the safety performance, insulating performance and production yield of the battery cell.

[0057] Finally, it should be noted that: the above embodiments are only specific embodiments of the present application, used to illustrate the technical solutions of the present application, rather than limiting it. 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, those of ordinary skill in the art should understand that: any person skilled in the art within the technical scope disclosed by the present application can still modify the technical solutions recorded in the foregoing embodiments or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all 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. An insulating structure, attached to the outer surface of a cell cover, wherein the cell cover is provided with a nickel sheet welding area and a pressure relief area, characterized in that: A first through hole is formed on the insulating structure, and a first window portion and a second window portion are formed in the first through hole, wherein the first window portion is used to show the nickel sheet welding area, and the second window portion is used to show the pressure relief area; The size of the nickel sheet welding area in the first direction is A1, the size of the first window portion in the first direction is A2, 3.5mm≤A2-A1≤4.5mm; The size of the pressure relief area in the first direction is B1, the size of the second window portion in the first direction is B2, and 0.2 mm ≤ B2 - B1 ≤ 0.4 mm.

2. The insulation structure according to claim 1, characterized in that: A2≠B2.

3. The insulation structure according to claim 2, characterized in that: The first window portion and the second window portion are arranged at an interval, and / or a transition portion is arranged between the first window portion and the second window portion.

4. The insulation structure according to claim 2, characterized in that: 2mm≤│A2-B2│≤6mm.

5. The insulation structure according to claim 1, characterized in that: The cover plate body of the battery cell cover plate is a rectangular plate-shaped structure, and the first direction is the width direction of the cover plate body.

6. The insulation structure according to claim 5, characterized in that: The first window portion and the second window portion are arranged at intervals along the length direction of the cover plate body.

7. The insulation structure according to claim 1, characterized in that: The insulating structure is also provided with a second through hole for allowing the protruding pole assembly on the battery cover to extend out.

8. The insulation structure according to claim 7, characterized in that: The minimum distance between the first through hole and / or the second through hole and the edge of the insulating structure is C, and C≥2 mm.

9. The insulation structure according to claim 1, characterized in that: The pressure relief area is equipped with a pressure relief assembly, which includes a pressure relief piece and a protective piece arranged on a side of the pressure relief piece facing the outside of the battery cell. B1 is the size of the protective piece in the first direction.

10. A battery cell, characterized in that: The insulating structure comprises any one of claims 1 to 9.

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