Battery cell and battery pack

Abstract

The utility model provides a battery cell and a battery pack, and belongs to the field of battery structures. The battery cell comprises a shell, a battery pack and a battery pack, wherein the shell is internally provided with a pole group; the pole column assembly comprises a column body and a welding piece, and the top end and the bottom end of the column body in the axis direction are welded to the welding piece and the pole group respectively; and the plate body assembly is assembled between the pole group and the welding piece. The bottom end of the column body is fixedly welded with the pole group, then the plate body assembly is correspondingly assembled on the outer side part of the column body, and then the welding piece is welded with the top end of the column body, namely, the battery cell in the embodiment is fixedly welded with the column body by utilizing the welding piece, and compared with a riveting mode in the prior art, the battery cell cancels a riveting block, has no influence of instantaneous impulsive force, and is convenient to assemble and disassemble. Therefore, the stability of the anti-explosion valve is improved, and meanwhile the space utilization rate can be increased.

Description

Technical Field

[0001] This application relates to the field of battery structures, and more particularly to a battery cell and a battery pack. Background Art

[0002] In existing battery cells, generally, the terminal post and the housing are connected by riveting. However, in the current riveting scheme, an instantaneous impact force is generated during riveting, which seriously affects the stability of the explosion-proof valve. In addition, the presence of the riveting block occupies the axial space of the battery cell, resulting in low space utilization. Summary of the Utility Model

[0003] In view of this, the purpose of this application is to provide a battery cell and a battery pack to solve the problems of low stability of the explosion-proof valve and low space utilization of the battery cell caused by the riveting connection between the terminal post and the housing in existing battery cells.

[0004] According to a first aspect of the present utility model, a battery cell is provided, wherein the battery cell includes:

[0005] A housing, inside which a pole group is arranged;

[0006] A terminal post assembly, including a column body and a welding member, the top and bottom of the column body in the axial direction are respectively welded to the welding member and the pole group; and

[0007] A plate body assembly, assembled between the pole group and the welding member.

[0008] Preferably, along the axial direction of the column body, the column body is formed with a first columnar section and a second columnar section connected in sequence, and the axes of the first columnar section and the second columnar section are collinear; the welding member is located at the top of the first columnar section away from the second columnar section.

[0009] Preferably, the second columnar section is formed into a stepped structure.

[0010] Preferably, along the diameter direction of the second columnar section, the second columnar section is formed with a transition portion and a fixing portion connected in sequence, and the transition portion is located on the side of the second columnar section close to the first columnar section; the bottom of the fixing portion away from the first columnar section is welded to the pole group.

[0011] Preferably, along the axial direction of the column body, the thickness of the transition portion is greater than the thickness of the fixing portion; and / or, the thickness of the fixing portion is 0.2 mm to 2 mm.

[0012] Preferably, a groove is formed at the center of the bottom of the second columnar section, and the groove extends to the first columnar section.

[0013] Preferably, along the axial direction of the cylinder, the distance between the top end of the first cylindrical section and the bottom of the groove is greater than the thickness of the transition portion.

[0014] Preferably, along the axial direction of the cylinder, the thickness of the welding piece is not greater than the distance between the top end of the first cylindrical section and the bottom of the groove.

[0015] Preferably, the plate assembly includes an upper plastic part, a sealing ring, and a lower plastic part.

[0016] According to a second aspect of the present invention, a battery pack is provided, which includes the battery cell as described above.

[0017] According to the battery cell and the battery pack of the present invention, the bottom end of the cylinder is welded and fixed to the pole group, then the plate assembly is correspondingly assembled on the outer side of the cylinder, and then the welding piece is welded to the top end of the cylinder. That is, in this embodiment, the battery cell is welded and fixed to the cylinder by the welding piece. Compared with the riveting method in the prior art, the riveting block is cancelled in this battery cell, and there is no influence of instantaneous impact force, thereby improving the stability of the explosion-proof valve and also improving the space utilization rate.

[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 are described in detail as follows. Description of the Drawings

[0019] To more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 is a partial cross-sectional view of a battery cell according to an embodiment of the present invention;

[0021] Figure 2 is a cross-sectional view of a pole column assembly according to an embodiment of the present invention.

[0022] Reference numerals: 1 - housing; 2 - pole group; 30 - cylinder; 301 - first cylindrical section; 302 - second cylindrical section; 3021 - transition portion; 3022 - fixing portion; 303 - groove; 31 - welding piece; 40 - upper plastic part; 41 - sealing ring; 42 - lower plastic part. Detailed Embodiments

[0023] The following specific embodiments are provided to assist the reader in obtaining a comprehensive understanding of the methods, apparatuses, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatuses, 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 exemplary and is not limited to the order set forth herein. Rather, changes that will be apparent after understanding the disclosure of this application may 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.

[0024] The features described herein may be implemented in different 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, apparatuses, and / or systems described herein that will be apparent after understanding the disclosure of this application.

[0025] 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 may be directly "on," "connected to," "coupled to," "above," or "covering" the other element, or there may be one or more other elements intervening therebetween. 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 may be no other elements intervening therebetween.

[0026] 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.

[0027] 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.

[0028] For ease of description, spatial relationship terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship between one element and another as shown in the accompanying drawings. 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 accompanying drawings. For example, if the device in the accompanying drawings is flipped, an element described as "above" or "upper" relative to another element will subsequently be "below" or "lower" relative to the other element. Thus, the term "above" includes both the orientation 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.

[0029] The terms used herein are for the purpose of describing various examples only and are not intended to limit the disclosure. Unless the context clearly dictates otherwise, the singular forms are also intended to include the plural forms. The terms "comprises", "comprising", and "having" list 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.

[0030] Due to manufacturing techniques and / or tolerances, variations in the shapes shown in the accompanying drawings may occur. Accordingly, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include changes in shape that occur during manufacturing.

[0031] The features of the examples described herein may be combined in various ways that will be apparent after understanding the disclosure of this application. Additionally, although the examples described herein have a variety of configurations, other configurations will be apparent after understanding the disclosure of this application.

[0032] According to a first aspect of the present utility model, a battery cell is provided, as Figures 1 to 2 shown, the battery cell in this embodiment includes a housing 1, a terminal assembly, and a plate assembly. A battery stack 2 is disposed inside the housing 1. The terminal assembly includes a column body 30 and a welding member 31. The top and bottom ends of the column body 30 in the axial direction are respectively welded to the welding member 31 and the battery stack 2, so as to be able to fix the plate assembly between the battery stack 2 and the welding member 31. Hereinafter, the specific structures of the above-mentioned various parts of the battery cell according to the present utility model will be described in detail.

[0033] As Figures 1 to 2As shown, along the axial direction of the column 30, the column 30 is formed with a first columnar section 301 and a second columnar section 302 connected in sequence, and the axes of the first columnar section 301 and the second columnar section 302 are collinear. Both the first columnar section 301 and the second columnar section 302 in this embodiment are formed into cylindrical structures, and their specifications and the like are not specifically limited, and should be determined comprehensively according to actual situations such as the specifications of the battery cells. In addition, a groove 303 is formed at the center of the bottom of the second columnar section 302 (close to the electrode group 2), and the groove 303 extends to the first columnar section 301, so that materials can be saved and the integral stamping forming of the column 30 is facilitated. Further, the second columnar section 302 in this embodiment is formed into a stepped structure. Along the diameter direction of the second columnar section 302, the second columnar section 302 is formed with a transition portion 3021 and a fixing portion 3022 connected in sequence, and the transition portion 3021 is located inside the second columnar section 302 close to the first columnar section 301.

[0034] The above-mentioned welding part 31 is located at the top of the first columnar section 301 away from the second columnar section 302 and is welded to the column 30, and the bottom end of the fixing portion 3022 away from the first columnar section 301 is welded to the electrode group 2; further, along the axial direction of the column 30, the thickness (L) of the transition portion 3021 is greater than the thickness (H) of the fixing portion 3022, and the distance (D) between the top end of the first columnar section 301 and the bottom of the groove 303 is greater than the thickness (L) of the transition portion 3021, that is, D > L > H; in addition, the thickness (A) of the welding part 31 is not greater than the distance (D) between the top end of the first columnar section 301 and the bottom of the groove 303, that is, A ≤ D, so as to ensure the welding stability of the column 30 with the welding part 31 and the electrode group 2. Preferably, the thickness of the fixing portion 3022 is 0.2 mm to 2 mm, and this numerical range is the optimal range that can achieve the above technical effects after multiple tests.

[0035] In this embodiment, the plate assembly includes an upper plastic part 40, a sealing ring 41 and a lower plastic part 42. During assembly, the three of them are correspondingly assembled on the outer side of the first columnar section 301, and then the welding part 31 is correspondingly welded to the column 30. In this way, through the welding part 31, the stable connection between the column 30 and the housing 1 and the plate assembly can be realized, and the sealing performance of the battery cell can be ensured; and the connection method of welding the welding part 31 to the column 30 can guide the current inside the battery cell to the outside to meet the use requirements of the battery cell.

[0036] Through the battery cell described above in this embodiment, the bottom end of the column 30 is fixedly welded to the electrode group 2, then the plate assembly is correspondingly assembled on the outer side of the column 30, and then the welding part 31 is welded to the top end of the column 30. That is, the battery cell in this embodiment is fixedly welded to the column 30 by the welding part 31. Compared with the riveting method in the prior art, the riveting block is eliminated in this battery cell, and there is no influence of instantaneous impact force, thereby improving the stability of the explosion-proof valve and at the same time improving the space utilization rate.

[0037] In addition, according to the second aspect of the present invention, a battery pack is provided, and the battery pack includes the battery cell described above.

[0038] Finally, it should be noted that the above-described embodiments are only specific embodiments 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 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 by the protection scope of the present application. Therefore, the protection scope of the present application should be the protection scope of the claims.

Claims

1. A battery cell, characterized in that: The battery cell comprises: A shell, wherein a pole group is arranged inside the shell; A pole assembly, comprising a pole body and a welding piece, wherein the top and bottom ends of the pole body in the axial direction are welded to the welding piece and the pole group respectively; and The plate assembly is assembled between the pole group and the welding piece.

2. The battery cell according to claim 1, characterized in that: Along the axis direction of the column, the column is formed with a first column segment and a second column segment connected in sequence, and the axes of the first column segment and the second column segment are collinear; the welding piece is located at the top end of the first column segment away from the second column segment.

3. The battery cell according to claim 2, characterized in that: The second columnar section is formed into a step-shaped structure.

4. The battery cell according to claim 3, characterized in that: Along the diameter direction of the second columnar segment, the second columnar segment is formed with a transition portion and a fixing portion connected in sequence, and the transition portion is located on a side of the second columnar segment close to the first columnar segment; the fixing portion is welded to the pole group away from the bottom end of the first columnar segment.

5. The battery cell according to claim 4, characterized in that: Along the axial direction of the column, the thickness of the transition portion is greater than the thickness of the fixing portion; and / or the thickness of the fixing portion is 0.2 mm to 2 mm.

6. The battery cell according to claim 4, characterized in that: A groove is formed at the center of the bottom of the second columnar segment, and the groove extends to the first columnar segment.

7. The battery cell according to claim 6, characterized in that: Along the axial direction of the column, the distance between the top of the first columnar segment and the bottom of the groove is greater than the thickness of the transition portion.

8. The battery cell according to claim 7, characterized in that: Along the axial direction of the column, the thickness of the welding piece is not greater than the distance between the top of the first columnar segment and the bottom of the groove.

9. The battery cell according to claim 1, characterized in that: The plate assembly includes an upper plastic part, a sealing ring and a lower plastic part.

10. A battery pack, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 9.

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