Battery Cells and Battery Packs

Abstract

The present invention relates to the field of battery technology, and in particular to a battery cell and a battery pack. The battery cell includes: a pole lug is provided on the pole group; a first liquid injection hole is provided on the cover body, a second liquid injection hole is provided on the insulating member, a protruding sink is formed on the side of the insulating member facing away from the cover body, the sink is formed into a ring structure with a notch, and the notch and the inner wall of the ring structure form a third liquid injection hole; the electrolyte is injected into the battery cell through the first liquid injection hole, the second liquid injection hole and the third liquid injection hole in sequence; a connector is connected to the pole lug and the pole column; and an adhesive is provided between the connector and the insulating member. The present invention provides a notched sink structure to form a space inside the battery cell for the electrolyte to flow in smoothly, so that while rapid liquid injection and vacuuming are achieved, there will be no electrolyte bubbling, thereby improving the production efficiency of the battery cell.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery cell and a battery pack. Background Art

[0002] As lithium-ion battery technology matures, lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage fields, and the requirements for the performance and safety of lithium-ion batteries are increasing. As an accessory in lithium-ion batteries, the lithium battery cover firstly seals the internal and external environments by welding with the aluminum shell, and secondly connects the internal and external circuits, and transmits the internal current of the battery to the outside through the top cover pole, playing a guiding role.

[0003] The traditional top cover is generally composed of a bare aluminum sheet, positive and negative poles, upper plastic, lower plastic, explosion-proof valve and explosion-proof valve protective film. During the production of the battery cell, after the cover plate and the shell are welded and sealed, the electrolyte is injected into the battery cell through the injection hole. At the same time, the battery cell is evacuated through the injection hole to exhaust the gas to ensure the amount of electrolyte injection in the battery cell. At present, the injection hole is set on the top cover. For traditional batteries, the connecting piece and the pole ear are located below the injection hole. In order to avoid welding slag between the connecting piece and the pole ear and overlapping short circuit between the pole ear and the shell, high-temperature resistant tape is affixed to the connecting piece and the pole ear. When injecting liquid, the injection rate is slowed down due to the obstruction of the tape below the injection hole, which affects the production efficiency. The electrolyte will also appear and cause the battery cell to be contaminated. In addition, when the electrolyte is injected through the injection hole and the battery cell is evacuated, the tape may block the injection hole and cause an alarm on the production line. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide a battery cell and a battery pack to solve the problem that when injecting liquid into the existing battery cell, the injection rate is slow, which affects the production efficiency and also causes electrolyte leakage, resulting in battery cell contamination.

[0005] A first aspect of the present invention provides a battery cell, wherein the battery cell comprises:

[0006] A pole group having protruding pole ears;

[0007] The cover plate body is provided with a first liquid injection hole, and the electrode group is arranged on a side of the cover plate body facing the inside of the battery cell;

[0008] A pole, mounted on the cover plate body;

[0009] an insulating member, arranged on a side of the cover body facing the inside of the battery cell, the insulating member being provided with a second injection hole, the insulating member being provided with a protruding sink on a side of the insulating member facing away from the cover body, the sink being formed into an annular structure with a notch, the notch and the inner wall of the annular structure forming a third injection hole; the electrolyte is sequentially injected into the battery cell through the first injection hole, the second injection hole and the third injection hole;

[0010] A connecting piece, connected to the pole lug and the pole;

[0011] The adhesive member is arranged between the connecting member and the insulating member.

[0012] Preferably, the radial dimension of the first injection hole is φ D, 2mm≤ φ D≤5mm.

[0013] Preferably, the radial dimension of the second injection hole is φ E, 2.5mm≤ φ E≤10mm,1.25≤ φ E / φ D≤10, the axis of the first injection hole coincides with the axis of the second injection hole.

[0014] Preferably, in the first direction, the distance between the end of the sink where the notch is provided and the hole wall of the second injection hole is f, and the dimension of the sink in the axial direction of the third injection hole is a;

[0015] φ E / 3≤f≤ φ E×3 / 4, 0.3mm≤a≤10mm, and / or 0.1≤a / f≤10.

[0016] Preferably, in the axial direction of the first liquid injection hole, the minimum distance between the first liquid injection hole and the second liquid injection hole is c, and c≥0.1 mm.

[0017] Preferably, the connecting member is arranged on the side of the sink, and the pole lug and the pole are arranged on two sides of the connecting member that are opposite to each other;

[0018] And / or, in the axial direction of the first liquid injection hole, the distance between the side of the sink facing the inside of the battery cell and the pole ear is g, and g≥0.1 mm.

[0019] Preferably, the sink is spaced apart from the connecting piece, and a minimum distance between an axial outer wall of the sink surrounding the third liquid injection hole and the connecting piece is b, where b≥0.3 mm.

[0020] Preferably, the depth of the second injection hole is d, 0.3mm≤d≤10mm.

[0021] Preferably, the third injection hole is arranged directly below the second injection hole, and the inner wall of the sink is coplanar with the hole wall of the second injection hole.

[0022] A second aspect of the present invention provides a battery pack, comprising the battery cell described in any of the above technical solutions.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The battery cell of the present invention is provided with a first injection hole on the cover plate body, and a second injection hole is provided on the insulating member. A protruding sink is formed on the side of the insulating member facing away from the cover plate body, and the sink is formed into a ring structure with a notch, and the inner wall of the notch and the ring structure surround the third injection hole; the electrolyte is injected into the battery cell through the first injection hole, the second injection hole and the third injection hole in sequence. Since the sink structure with a notch is provided to form a space for the electrolyte to flow smoothly inside the battery cell, the injection flow rate of the electrolyte is guaranteed, and it can also avoid the adhesive component blocking the third injection hole during vacuum extraction, resulting in production line suspension. Therefore, while achieving rapid injection and vacuum extraction, there will be no electrolyte bubbling, thereby improving the production efficiency of the battery cell.

[0025] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A schematic diagram of the structure of a battery cell provided in an embodiment of the present invention;

[0028] Figure 2 For along Figure 1 The cross-section taken at AA in the middle;

[0029] Figure 3 For along Figure 2 The cross-section taken at BB in the middle;

[0030] Figure 4 for Figure 3 Schematic diagram of the enlarged structure at K in the middle;

[0031] Figure 5 for Figure 4 The dimensions of the components and the schematic diagram of the dimensioning positions between the components;

[0032] Figure 6 A schematic diagram of the structure of a cover plate assembly in a battery cell provided in an embodiment of the present invention;

[0033] Figure 7 for Figure 6 Schematic diagram of the enlarged structure at M in the middle;

[0034] Figure 8 A schematic diagram of the structure of an insulating component in a battery cell provided in an embodiment of the present invention.

[0035] Icons: 10-pole group; 11-pole ear; 21-cover body; 211-first liquid injection hole; 22-insulating member; 221-second liquid injection hole; 222-sinking platform; 2221-notch; 2222-third liquid injection hole; 23-pole; 30-connecting member; 40-adhesive member; 50-shell; D1-first direction. DETAILED DESCRIPTION

[0036] 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 apparent. For example, the order of operations described herein is merely an example, and is not limited to the order set forth herein, but in addition to the operations that must occur in a particular order, changes that will be apparent after understanding the disclosure of the present application may be made. In addition, in order to improve clarity and brevity, descriptions of features known in the art may be omitted.

[0037] The features described herein may be implemented in different forms and should not be interpreted as being limited to the examples described herein. Rather, the examples described herein have been 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.

[0038] Throughout the specification, when an element (such as a layer, a region, or a substrate) is described as being “on”, “connected to”, “bound to”, “over”, or “covering” another element, it may be directly “on”, “connected to”, “bound to”, “over”, or “covering” another element, or one or more other elements may be present between them. In contrast, when an element is described as being “directly on”, “directly connected to”, “directly bound to”, “directly over”, or “directly covering” another element, there may be no other elements present between them.

[0039] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0040] Although terms such as "first," "second," and "third" may 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. Therefore, without departing from the teachings of the examples described herein, the first member, component, region, layer, or portion referred to may also be referred to as the second member, component, region, layer, or portion.

[0041] For ease of description, spatial relational terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another element as shown in the accompanying drawings. Such spatial relational terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, an element described as being "above" or "upper" relative to another element will subsequently be "below" or "lower" relative to the 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 relational terms used herein will be interpreted accordingly.

[0042] The terms used herein are only used to describe various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "include", "comprise" and "have" list the stated features, quantities, operations, components, elements and / or their combinations that exist, but do not exclude the existence or addition of one or more other features, quantities, operations, components, elements and / or their combinations.

[0043] Variations in the shapes shown in the 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 drawings but include variations in shapes that occur during manufacturing.

[0044] The features of the examples described herein may 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.

[0045] According to a first aspect of the present invention, a battery cell is provided, which specifically includes an electrode group 10 , a cover plate body 21 , a pole 23 , an insulating member 22 , a connecting member 30 and an adhesive member 40 .

[0046] Hereinafter, a specific structure of the battery cell according to this embodiment will be described.

[0047] In this embodiment, a first injection hole 211 is provided on the cover body 21, the electrode group 10 and the insulating member 22 are both arranged on the side of the cover body 21 facing the inside of the battery cell, and the pole 23 is installed on the cover body 21. A second injection hole 221 is provided on the insulating member 22, and a protruding sink 222 is formed on the side of the insulating member 22 facing away from the cover body 21. The sink 222 is formed into an annular structure with a notch 2221. The notch 2221 and the inner wall of the annular structure form a third injection hole 2222, so that the electrolyte can be injected into the battery cell through the first injection hole 211, the second injection hole 221 and the third injection hole 2222 in sequence.

[0048] like Figure 2 and Figure 4 As shown, the connector 30 is formed into a sheet structure, which is used to connect the pole lug 11 and the pole post 23, that is, the pole lug 11 and the pole post 23 are respectively welded on the connector 30; the adhesive member 40 is arranged between the connector 30 and the insulating member 22, and the adhesive member 40 can be a high temperature resistant tape. The adhesive member 40 is attached to the side of the connector 30 facing the insulating member 22 and part of the pole group 10.

[0049] Since the sink 222 structure with the notch 2221 is provided to form a space inside the battery cell for the electrolyte to flow in smoothly, the electrolyte injection flow rate is guaranteed, and it can also avoid the adhesive 40 blocking the third injection hole 2222 during vacuuming, causing production line suspension. Therefore, while achieving rapid injection and vacuuming, there will be no electrolyte bubbling, thereby improving the production efficiency of the battery cell.

[0050] In this embodiment, the axial direction of the first injection hole 211, the axial direction of the second injection hole 221 and the axial direction of the third injection hole 2222 are the same. Preferably, the first injection hole 211, the second injection hole 221 and the third injection hole 2222 are coaxially arranged, so as to facilitate the electrolyte to flow smoothly into the battery cell.

[0051] Specifically, in this embodiment, Figure 2 and Figure 3 As shown, the pole group 10 is arranged inside the housing 50. The pole group 10 is formed by stacking or winding pole pieces, and the side of the pole group 10 has a protruding pole ear 11. The cover plate assembly includes a cover plate body 21, an insulating member 22 and a pole 23. The cover plate body 21 is formed into a plate-like structure. The shape of the cover plate body 21 is adapted to the shape of the housing 50. For example, when the housing 50 is a rectangular shell-like structure, the cover plate body 21 is a rectangular plate-like structure; when the housing 50 is cylindrical, the cover plate body 21 is a circular plate-like structure.

[0052] In a preferred embodiment, Figure 2 and Figure 3 As shown, the pole 23 is assembled on the cover body 21, the first injection hole is opened on the cover body 21, the two ends of the pole 23 in the axial direction extend out of the two sides in the thickness direction of the cover body 21, and the insulating member 22 is arranged on the side of the cover body 21 facing the inside of the battery cell, which is used to separate the cover body 21 and the shell 50 from the pole 23 and the pole group 10, so as to play the role of insulation protection and reduce the risk of short circuit.

[0053] In this embodiment, the housing 50 and the cover body 21 are made of metal materials, such as aluminum or steel, and the insulating member 22 is made of plastic material, such as PP.

[0054] Further, in a preferred embodiment, as Figures 1 to 4 as well as Figures 6 to 8As shown, the first injection hole 211 is opened on the cover body 21, and the first injection hole 211 is a through hole structure that runs through the thickness direction of the cover body 21. The first injection hole 211 is connected to the second injection hole 221, and the second injection hole 221 is a through hole structure that runs through the thickness direction of the insulating member 22. The sink 222 is formed by the side of the insulating member 22 that protrudes outwardly from the cover body 21. The adhesive member 40 is spaced apart from the sink in the thickness direction of the cover body 21. In this way, after the battery cell is assembled, the electrolyte passes through The liquid flows from the first injection hole 211 to the second injection hole 221, and then flows to the interior of the battery cell through the gap 2221 of the sinker 222. When vacuuming, even if the adhesive 40 moves toward the sinker 222 under the action of vacuum suction, since the sinker 222 is a non-closed annular structure with a gap 2221, it can ensure smooth electrolyte injection, thereby improving the injection efficiency and the production efficiency of the battery cell. Moreover, when vacuuming, the adhesive 40 will not completely block the third injection hole 2222, thereby ensuring smooth production.

[0055] In a preferred embodiment, Figures 6 to 8 As shown, the sink 222 is a semicircular ring structure, which can effectively separate the second injection hole 221 and the adhesive member 40 while increasing the flow rate of the electrolyte injected into the battery cell, thereby improving the production efficiency of the battery cell.

[0056] Further, in a preferred embodiment, as Figures 6 to 8 As shown, the third injection hole 2222 is arranged directly below the side of the second injection hole 221 facing away from the first injection hole 211, and the inner wall of the annular structure of the sinker 222 is coplanar with the hole wall of the second injection hole 221, so that the sinker 222 has a certain electrolyte diversion function, thereby increasing the rate at which the electrolyte enters the battery cell.

[0057] In this embodiment, if Figure 5 As shown, the radial dimension of the first injection hole 211 is φ D, 2mm≤ φ D≤5mm, where φ D is preferably 3 mm, so as to ensure smooth injection and vacuum extraction, improve injection efficiency, and thus improve the production efficiency of the battery cell.

[0058] Furthermore, in this embodiment, if Figure 5 As shown, the axis of the first injection hole 211 coincides with the axis of the second injection hole 221, so that the radial dimension of the second injection hole 221 is larger than the radial dimension of the first injection hole 211, ensuring that the flow rate of the electrolyte can smoothly enter the interior of the housing 50 and avoiding the occurrence of electrolyte bubbling. Preferably, the radial dimension of the second injection hole 221 is φ E, 2.5mm≤ φ E≤10mm,1.25≤ φE / φ D≤10, thereby ensuring the insulation protection performance of the insulating member 22 on the cover body 21 and facilitating the installation of the sealing plug after the injection is completed. It should be noted that the sealing plug is a rubber plug that can block the second injection hole 221 after the injection is completed to prevent electrolyte leakage.

[0059] Furthermore, in this embodiment, if Figure 5 As shown, in the first direction D1, the distance between the end of the sink 222 provided with the notch and the hole wall of the second liquid injection hole 221 is f, φ E / 3≤f≤ φ E×3 / 4, so that there is a sufficient and effective communication volume between the second injection hole 221 and the inside of the battery cell to ensure the flow rate of the injected electrolyte, and no leakage will occur during rapid injection and vacuuming. It should be noted that the first direction D1 can be the thickness direction of the battery cell or the width direction of the cover body 21.

[0060] In this embodiment, if Figure 5 As shown, the axial dimension of the sinker 222 in the third injection hole 2222 is a, that is, the dimension of the sinker 222 in the thickness direction of the cover plate body 21 is a, 0.3mm≤a≤10mm, preferably, 0.1≤a / f≤10, so as to ensure that there is a sufficient distance between the second injection hole 221 and the adhesive 40, to ensure smooth electrolyte injection, to speed up the injection rate, to avoid electrolyte bubbling, to improve the production efficiency of the battery cell, and to reduce the risk of the adhesive 40 blocking the third injection hole 2222 when vacuuming, thereby ensuring smooth production.

[0061] In this embodiment, if Figure 5 As shown, in the axial direction of the first injection hole 211, that is, in the thickness direction of the cover plate body 21, the minimum distance between the first injection hole 211 and the second injection hole 221 is c, that is, in the thickness direction of the cover plate body 21, the distance between the end surfaces of the first injection hole 211 and the second injection hole 221 relative to each other is c, c ≥ 0.1mm, so that an assembly gap is formed between the first injection hole 211 and the second injection hole 221 to avoid interference between the first injection hole 211 and the second injection hole 221, thereby ensuring the shape accuracy of the second injection hole 221 and the flow rate of the injected electrolyte.

[0062] In this embodiment, if Figure 3 and Figure 4 As shown, the connector 30 is disposed on the side of the sink 222 , and the tabs 11 and the poles 23 are disposed on opposite sides of the connector 30 . Specifically, the tabs 11 and the poles 23 are respectively connected to the two sides of the connector 30 in the thickness direction.

[0063] In this embodiment, if Figure 5As shown, in the axial direction of the first injection hole 211, that is, in the thickness direction of the cover body 21, the distance between the side of the sinker 222 facing the inside of the battery cell and the pole ear 11 is g, g ≥ 0.1mm, so as to avoid interference between the sinker 222 and the pole ear 11, and prevent deformation of the sinker 222 or wear of the pole ear 11.

[0064] In this embodiment, if Figure 5 As shown, the sinker 222 is spaced apart from the connector 30, and the minimum distance between the axial outer wall of the sinker 222 surrounding the third injection hole 2222 and the connector 30 is b, b≥0.3mm, so as to avoid interference between the sinker 222 and the connector 30, prevent deformation of the sinker 222, and affect the flow rate of the electrolyte.

[0065] In this embodiment, if Figure 5 As shown, the depth of the second injection hole 221 is d, 0.3mm≤d≤10mm, which ensures the structural strength of the second injection hole 221, reduces the damage caused by the impact of the electrolyte, and also avoids the second injection hole 221 occupying the space inside the battery cell and reducing the energy density of the battery cell.

[0066] The following are different φ D. φ The production line production status of battery cells of sizes E, a and f is tested, and the test results are shown in Table 1 below.

[0067] Table 1

[0068]

[0069] Note: The failure mode “ / ” in the table indicates that the battery cell production is normal, and there is no difficulty in installing the sealing plug, abnormal vacuuming or difficulty in injecting liquid.

[0070] As shown in Table 1, in Examples 1 to 6, φ D. φ E, a, f, a / f, and φ E / φ D are all within the specified range, and there is no difficulty in installing the sealing plug, abnormal vacuuming or difficulty in injecting liquid during the production process of the battery cell; while in Comparative Example 1, the main reason for the difficulty in installing the sealing plug is φ E / φThe reason is that the parameter D is too small. In Example 2, blockage occurs when vacuuming the battery cell. The abnormal vacuuming is mainly caused by the excessive size of a. The difficulty in injection in Example 3 is mainly caused by the excessive size of a / f. The difficulty in injection in Example 4 is mainly caused by the excessive size of f. The difficulty in injection in Example 5 is mainly caused by the excessive size of f. When the size of a is a constant, the risk of the adhesive 40 blocking the third injection hole 2222 during vacuuming increases due to the excessive size of f.

[0071] According to a battery cell provided by the present invention, a first injection hole is provided on the cover plate body, a second injection hole is provided on the insulating member, a protruding sink is formed on the side of the insulating member facing away from the cover plate body, the sink is formed into a ring structure with a notch, and the inner wall of the notch and the ring structure forms a third injection hole; the electrolyte is injected into the battery cell through the first injection hole, the second injection hole and the third injection hole in sequence, and a sink structure with a notch is provided to form a space for the electrolyte to flow smoothly inside the battery cell, thereby ensuring the injection flow rate of the electrolyte, and also preventing the adhesive from blocking the third injection hole during vacuuming, thereby causing production line suspension, so that rapid injection and vacuuming can be achieved without electrolyte bubbling, thereby improving the production efficiency of the battery cell.

[0072] A battery pack provided according to the present invention includes the battery cell as described above, wherein at least one battery cell is provided. When multiple battery cells are provided, at least some of the battery cells are connected in series and / or in parallel. The production efficiency and performance of each battery cell can be guaranteed, thereby effectively improving the production efficiency and safety of the battery pack.

[0073] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; 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 be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A battery cell, characterized in that: The battery cell comprises: A pole group having protruding pole ears; The cover plate body is provided with a first liquid injection hole, and the electrode group is arranged on a side of the cover plate body facing the inside of the battery cell; A pole, mounted on the cover plate body; an insulating member, arranged on a side of the cover body facing the inside of the battery cell, a second injection hole being opened on the insulating member, a protruding sinking platform being formed on a side of the insulating member facing away from the cover body, the sinking platform being formed into an annular structure with a notch, the notch being arranged on a side of the insulating member facing the inside of the battery cell, the notch and the inner wall of the annular structure forming a third injection hole; the electrolyte is sequentially injected into the battery cell through the first injection hole, the second injection hole and the third injection hole; A connecting piece, connected to the pole lug and the pole; An adhesive member, arranged between the connecting member and the insulating member; The radial dimension of the first injection hole is φ D, 2mm≤ φ D≤5mm; The radial dimension of the second injection hole is φ E, 2.5mm≤ φ E≤10mm,1.25≤ φ E / φ D≤10, the axis of the first injection hole coincides with the axis of the second injection hole; In the first direction, the distance between the end of the sink where the notch is provided and the hole wall of the second injection hole is f, and the dimension of the sink in the axial direction of the third injection hole is a; φ E / 3≤f≤ φ E×3 / 4,0.3mm≤a≤10mm,0.1≤a / f≤10。 2. The battery cell according to claim 1, characterized in that: In the axial direction of the first liquid injection hole, the minimum distance between the first liquid injection hole and the second liquid injection hole is c, and c≥0.1 mm.

3. The battery cell according to claim 1, characterized in that: The connecting member is arranged on the side of the sink, and the pole lug and the pole are arranged on two sides of the connecting member that are opposite to each other; And / or, in the axial direction of the first liquid injection hole, the distance between the side of the sink facing the inside of the battery cell and the pole ear is g, and g≥0.1 mm.

4. The battery cell according to claim 1, characterized in that: The sink is spaced apart from the connecting piece, and a minimum distance between an axial outer wall of the sink surrounding the third liquid injection hole and the connecting piece is b, where b≥0.3 mm.

5. The battery cell according to claim 1, characterized in that: The depth of the second injection hole is d, 0.3mm≤d≤10mm.

6. The battery cell according to claim 1, characterized in that: The third injection hole is arranged directly below the second injection hole, and the inner wall of the sink is coplanar with the hole wall of the second injection hole.

7. A battery pack, characterized in that: A battery cell comprising any one of claims 1 to 6.

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