Battery cell and battery pack

Abstract

The utility model provides a battery cell and a battery pack, the battery cell comprises a shell, the end part of the shell is provided with a cover plate assembly, and the cover plate assembly comprises a pole; the pole group is arranged in the shell, a pole lug is arranged at the end part of the pole group, and the pole lug is connected with the pole column; a connecting groove is formed in the end part, facing the pole lug, of the pole column, the end part, connected with the pole column, of the pole lug is arranged in the connecting groove, and the pole column part is arranged in the shell. According to the battery cell, the pole group is matched with the shell, the structures of the pole lugs of the pole group and the pole columns of the cover plate assembly are improved, so that the pole columns are provided with the connecting grooves, the pole lugs are arranged in the pole columns, the occupied space is reduced by changing the welding position, the overall size is further reduced, the utilization space in the shell is further improved, and the battery cell is convenient to use. And the capacity of the battery is increased.

Description

Technical Field

[0001] The present application relates to the technical field of power batteries, and particularly relates to a battery cell and a battery pack. Background Art

[0002] With the increasing maturity of lithium-ion battery technology, lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage fields, and the requirements for the use performance and safety of lithium-ion batteries are increasing day by day. The lithium battery cell is a core component for the safety and assembly of the battery pack, and its structural design is crucial for the safety of the battery cell.

[0003] In the existing battery cells, since the tab needs to be welded to the terminal, the tab and the terminal each need to occupy space. In addition, each of the positive and negative cover plates further includes many structural components, such as a light aluminum plate, upper and lower plastics, and a welding ring, etc. Due to the large number of structural components, the occupied space is large, which has a great impact on the capacity of the battery cell.

[0004] Therefore, it is necessary to design a battery cell to solve the above problems. Summary of the Utility Model

[0005] In view of this, in order to overcome the defects of the prior art, the present utility model provides a battery cell and a battery pack, which effectively solve the problem that the existing battery cell has a large occupied space due to a large number of structural components, which has a great impact on the capacity of the battery cell.

[0006] According to a first aspect of the present utility model, there is provided a battery cell, wherein the battery cell includes a housing, a cover plate assembly is provided at an end of the housing, and the cover plate assembly includes a terminal; a pole group is provided inside the housing, a tab is provided at an end of the pole group, and the tab is connected to the terminal; a connection groove is provided at an end of the terminal facing the tab, and an end of the tab connected to the terminal is disposed inside the connection groove, and a part of the terminal is disposed inside the housing.

[0007] Preferably, the terminal includes an extension part and a first connection part connected to each other, the extension part is disposed outside the housing, the first connection part penetrates through the housing, and the connection groove is provided in the first connection part.

[0008] Preferably, the tab includes a second connection part and an inclined platform connection part connected to each other, at least a part of the second connection part is disposed in the connection groove, the second connection part is connected to the first connection part, and the inclined platform connection part is disposed at an end of the pole group facing the terminal.

[0009] Preferably, a cross-section of the first connection part is formed into a U-shaped structure, a cross-section of the second connection part is formed into an L-shaped structure, and a long side of the L-shaped structure is welded to an inner side of a long horizontal side of the U-shaped structure.

[0010] Preferably, the electrode group includes a positive end and a negative end. The positive end of the electrode group is connected to the cover plate assembly through an end plate; and / or the negative end of the electrode group is connected to the cover plate assembly; the end plate is disposed between the cover plate assembly and the electrode group.

[0011] Preferably, the cover plate assembly includes a cover plate main body, a first plastic part, a second plastic part, a welding ring and a seal. The pole column penetrates through the cover plate main body, and the welding ring is sleeved on the extension part; the first plastic part, the seal and the second plastic part are all disposed between the first connecting part and the cover plate main body, and the first plastic part, the seal and the second plastic part are arranged in sequence from top to bottom.

[0012] Preferably, the battery cell further includes an explosion-proof valve, and the explosion-proof valve is disposed on the cover plate main body or the housing; and / or the battery cell further includes a liquid injection port, and the liquid injection port is disposed on the cover plate main body or the housing.

[0013] Preferably, the tab is connected to the pole column through a connecting piece.

[0014] Preferably, the battery cell further includes a side plate and an insulating film. The insulating film is disposed on the outer periphery of the electrode group, and the side plate is disposed between the housing and the insulating film.

[0015] According to a second aspect of the present invention, a battery pack is provided, wherein the battery pack includes the battery cell as described above.

[0016] According to the battery cell of the present invention, through the cooperation of the electrode group and the housing, the structures of the tab of the electrode group and the pole column of the cover plate assembly are improved, so that a connecting groove is formed in the pole column, so that the tab is disposed inside the pole column. By changing the welding position, the occupied space is reduced, and thus the overall volume is reduced. Furthermore, the utilization space inside the housing is increased, and the capacity of the battery is increased.

[0017] To make the above objects, features and advantages of the present application more obvious and understandable, the following specific preferred embodiments are given in detail in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use 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 therefore 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.

[0019] Figure 1 An exploded view of a battery cell showing an embodiment according to the present invention;

[0020] Figure 2 Shows a front view of a battery cell according to an embodiment of the present utility model;

[0021] Figure 3 Shows a battery cell according to an embodiment of the present utility model Figure 2 A cross-sectional view taken along line A-A;

[0022] Figure 4 Shows a schematic structural view of the negative electrode of a battery cell according to an embodiment of the present utility model;

[0023] Figure 5 Shows a schematic structural view of the positive electrode of a battery cell according to an embodiment of the present utility model;

[0024] Figure 6 Shows a schematic structural view of a terminal post and a tab according to an embodiment of the present utility model;

[0025] Figure 7 Shows a schematic structural view of an end plate according to an embodiment of the present utility model;

[0026] Figure 8 Shows a schematic structural view of a cover assembly according to an embodiment of the present utility model.

[0027] Reference numerals: 1 - housing; 2 - electrode group; 3 - cover assembly; 301 - cover body; 302 - first plastic part; 303 - second plastic part; 304 - welding ring; 305 - seal; 4 - terminal post; 401 - connecting groove; 402 - extension part; 403 - first connecting part; 5 - tab; 501 - second connecting part; 502 - inclined platform connecting part; 6 - end plate; 7 - side plate; 8 - insulating film. Detailed implementation manners

[0028] The following detailed implementation manners 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 an example and is not limited to the order set forth herein. 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.

[0029] 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.

[0030] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being "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 therebetween. In contrast, when an element is described as being "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 therebetween.

[0031] 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.

[0032] 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, a first component, element, region, layer, or part referred to in the examples described herein may also be referred to as a second component, element, region, layer, or part without departing from the teachings of the examples.

[0033] 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.

[0034] The terms used herein are for describing various examples only and are not intended to limit the examples. 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.

[0035] 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.

[0036] 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. Additionally, although the examples described herein have various configurations, other configurations are possible, as will be apparent after understanding the disclosure of the present application.

[0037] According to a first aspect of the present utility model, a battery cell is provided, as Figures 1 to 8 shown. The battery cell can be used in new energy vehicles or the field of electrical energy storage. The battery cell includes a housing 1 and an electrode assembly 2.

[0038] In the following description, the detailed structures of the housing 1 and the electrode assembly 2 of the battery cell will be specifically described with reference to Figures 1 to 8 the drawings.

[0039] As Figure 1 and Figure 2 shown, in an embodiment, a cover assembly 3 is provided at an end of the housing 1. Specifically, cover assemblies 3 are provided at both ends of the housing 1 to form the positive and negative electrodes of the battery cell. The electrode assembly 2 is disposed inside the housing 1, and the housing 1 can protect the electrode assembly 2. An electrode tab 5 is provided at an end of the electrode assembly 2. Specifically, electrode tabs 5 are provided at both ends of the electrode assembly 2 to form the positive and negative electrodes with the cover assembly 3. The cover assembly 3 includes a terminal post 4, and the terminal post 4 is connected to the electrode tab 5. The specific connection method can be welding. The connection between the terminal post 4 and the electrode tab 5 is used to achieve current transmission.

[0040] As Figures 3 to 6As shown, in the embodiment, a connection groove 401 is provided at the end of the pole post 4 facing the tab 5. The end of the tab 5 connected to the pole post 4 is disposed inside the connection groove 401, and a part of the pole post 4 is disposed inside the housing 1. Since the connection groove 401 is recessed into the interior of the pole post 4, the pole post 4 is formed with a notch, thereby reducing the overall volume. As a result, the tab 5 can be welded inside the pole post 4, thus reducing the occupied space and improving the utilization space inside the housing 1, enabling a larger electrode group 2 to be accommodated, and thereby increasing the battery capacity.

[0041] Since the welding position of the tab 5 and the pole post 4 of this battery cell is set inside the pole post 4, the occupied space of these two is reduced, and thus the utilization space inside the housing 1 is increased, enabling the battery capacity to be improved.

[0042] Preferably, as Figures 3 to 6 As shown, in the embodiment, the pole post 4 includes an extension part 402 and a first connection part 403 connected to each other. The connection mode of the extension part 402 and the first connection part 403 can be integrally formed or welded. The extension part 402 is disposed outside the housing 1 for transmitting current, facilitating subsequent assembly and use. The first connection part 403 penetrates the housing 1 so that it can be welded to the tab 5 while enabling the extension part 402 to be disposed outside the housing 1. The connection groove 401 is provided on the first connection part 403, and the connection groove 401 is provided at the end of the first connection part 403 facing the tab 5. In this way, the pole post 4 and the tab 5 can reduce the occupied space by setting the welding position at the connection groove 401. The reduced space is the volume of the connection groove 401. In addition, such a setting can also reduce the weight.

[0043] Preferably, as Figures 3 to 6 As shown, in the embodiment, the tab 5 includes a second connection part 501 and a bevel connection part 502 connected to each other. The connection mode of the second connection part 501 and the bevel connection part 502 is integrally formed. At least a part of the second connection part 501 is disposed in the connection groove 401. The second connection part 501 is connected to the first connection part 403, and the connection mode can be welding. The bevel connection part 502 is disposed at the end of the electrode group 2 facing the pole post 4. The tab 5 is welded to the end of the electrode group 2 through the bevel connection part 502. Since the welding area of the bevel connection part 502 is large, the connection between the tab 5 and the electrode group 2 is firm, and it is also convenient for welding. The second connection part 501 extends from the side of the bevel connection part 502 facing the first connection part 403 towards the first connection part 403 and bends, and then contacts and is welded to the second connection part 501. In this way, the second connection part 501 and the first connection part 403 can reduce the occupied space and also reduce the weight of the pole post 4 by setting the welding position at the connection groove 401.

[0044] Preferably, asFigures 3 to 6 As shown, in the embodiment, the cross-section of the first connecting portion 403 is formed into a U-shaped structure, and the cross-section of the second connecting portion 501 is formed into an L-shaped structure. The long side of the L-shaped structure is welded to the horizontal side of the U-shaped structure. Here, the U-shaped structure and the L-shaped structure can be understood as the shapes in the sectional view as shown in Figure 6 , such as Figure 8 shown, the first connecting portion 403 can be formed into a structure similar to a frustum of a cone. Here, it is described with the shape in Figure 6 .

[0045] The U-shaped structure can include two short horizontal sides, one long horizontal side, and two vertical sides. The two ends of the long horizontal side are respectively connected to the two short horizontal sides through the two vertical sides. These five sides are connected end to end to enclose a connecting groove 401. The long side of the following L-shaped structure is located inside the connecting groove 401, that is, the long side of the L-shaped structure is welded to the inner side of the long horizontal side of the U-shaped structure. The two short horizontal sides of the first connecting portion 403 of the U-shaped structure can facilitate the clamping of the first connecting portion 403 with the following cover body 301, and facilitate the fixing and installation of the pole column 4; the long horizontal side of the first connecting portion 403 of the U-shaped structure is used for the contact and welding fixation of the pole ear 5. In order to facilitate welding, the length of the long horizontal side is relatively long, and the length is greater than the length of the long side of the second connecting portion 501 of the L-shaped structure. The second connecting portion 501 of the L-shaped structure includes two long sides and a short side connected to each other. In the embodiment, the long side can be perpendicular to the short side. During actual use, the long side is bent from the position where the short side is located, thereby forming the second connecting portion 501 of the L-shaped structure. The length of the long side is shorter than the length of the long horizontal side of the first connecting portion 403, so that the long side can be welded to the long horizontal side, and the second connecting portion 501 is welded to the connecting groove 401. The short side extends from the inclined platform connecting portion 502 towards the direction where the pole column 4 is located, facilitating welding.

[0046] Preferably, as shown in Figure 1 and Figure 2 , in the embodiment, the electrode group 2 includes a positive extreme and a negative extreme. In Figure 1 , the left side of the electrode group 2 is the negative extreme, and the right side is the positive extreme. The positive extreme of the electrode group 2 is connected to the cover assembly 3 through the end plate 6, and the negative extreme of the electrode group 2 is directly connected to the cover assembly 3; since the pole ear 5 of the negative extreme is shorter, an additional end plate 6 is not required. However, it is not limited thereto. In order to improve the insulation performance, the negative extreme of the electrode group 2 can also be connected to the cover assembly 3 through the end plate 6.

[0047] Preferably, as shown in Figure 5 , in the embodiment, the end plate 6 is arranged between the cover assembly 3 and the electrode group 2. The end plate 6 is used to prevent the pole column 4 and the pole ear 5 from contacting the housing 1 or the cover body 301 to cause a short circuit.

[0048] Preferably, as shown in Figure 4 andFigure 5 As shown, in the embodiment, the cover plate assembly 3 includes a cover plate main body 301, a first plastic part 302, a second plastic part 303, a welding ring 304 and a seal 305. Specifically, the cover plate main body 301 can be a light aluminum plate in the prior art. The first plastic part 302 and the second plastic part 303 can both be plastic parts made of plastic, and the seal 305 can be a sealing ring. The pole column 4 penetrates through the cover plate main body 301, and the welding ring 304 is sleeved on the outer extension part 402 of the pole column 4 to fix the pole column 4. The first plastic part 302 and the second plastic part 303 can be an upper plastic and a lower plastic respectively. The first plastic part 302, the seal 305 and the second plastic part 303 are all arranged between the first connection part 403 and the cover plate main body 301, and the first plastic part 302, the seal 305 and the second plastic part 303 are arranged in sequence from top to bottom. Among them, the upper plastic is used to prevent the pole column 4 and the welding ring 304 from contacting the cover plate main body 301 and causing a short circuit, and the lower plastic is used to prevent the electrode group 2 and the pole column 4 from contacting the cover plate main body 301 and causing a short circuit.

[0049] Preferably, in the embodiment, the battery cell can further include an explosion-proof valve. When abnormal conditions occur inside the battery cell, such as overcharging, over-discharging and short circuit, etc., the explosion-proof valve can cut off the current of the battery cell in time, avoid accidents such as fire and explosion of the battery cell, and ensure personal and property safety; at the same time, the explosion-proof valve of the battery cell can reduce the pressure burden of the battery cell, avoid damage caused by excessive pressure of the battery cell, thereby prolong the service life of the battery, and can also limit the internal voltage of the battery cell within a certain range, avoid waste of energy caused by overcharging, and improve the charging efficiency. The explosion-proof valve is arranged on the cover plate main body 301 or the housing 1, and can be set according to needs and actual usage conditions. For example, it can be set on the cover plate main body 301 at the positive electrode, on the cover plate main body 301 at the negative electrode, both the cover plate main bodies 301 at the positive and negative electrodes are set or on the housing 1.

[0050] Preferably, in the embodiment, the battery cell can further include a liquid injection port for injecting liquid electrolyte. The liquid injection port is arranged on the cover plate main body 301 or the housing 1, and can be set according to needs and actual usage conditions. For example, it can be set on the cover plate main body 301 at the positive electrode, on the cover plate main body 301 at the negative electrode, both the cover plate main bodies 301 at the positive and negative electrodes are set or on the housing 1.

[0051] Preferably, in the embodiment, the tab 5 can be connected to the pole column 4 through a connecting piece. The connecting piece has the function of transmitting current. However, it is not limited to this, and whether to use the connecting piece can be selected according to needs and actual usage conditions.

[0052] Preferably, as Figure 1As shown, in the embodiment, the battery cell may further include a side plate 7 and an insulating film 8. The insulating film 8 is disposed on the outer periphery of the electrode group 2, and the side plate 7 is disposed between the housing 1 and the insulating film 8. The insulating film 8 is disposed on the outer periphery of the electrode group 2, and the side plate 7 is disposed between the housing 1 and the insulating film 8. The insulating film 8 may cover the outer periphery of the electrode group 2 and mainly serves as an isolation layer, a protection layer, and an electrolyte infiltration layer. The insulating film 8 may be a polyester film. The side plate 7 is disposed on the side of the electrode group 2 to protect the side of the battery cell. However, it is not limited thereto. The position of the side plate 7 may be selected according to needs and actual usage conditions and may be disposed on both sides of the electrode group 2 (such as Figure 1 the upper and lower sides in

[0053] ), or the side plate 7 may not be provided.

[0054] Furthermore, according to a second aspect of the present invention, a battery pack is provided. The battery pack includes the battery cell as described above. Since the battery cell as described above is used in the battery pack, and since the capacity of each battery cell can be increased, the overall capacity of the battery pack is increased, thereby increasing the endurance.

[0055] 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 and are not intended 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 or easily conceive of changes to the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications, changes, or replacements 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 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. A battery cell, characterized in that: The battery cell comprises: A shell, a cover plate assembly is disposed at an end of the shell, and the cover plate assembly includes a pole; A pole group is arranged inside the shell, and a pole ear is arranged at the end of the pole group, and the pole ear is connected to the pole column; The end of the pole facing the pole ear is provided with a connection groove, the end of the pole ear connected to the pole is arranged inside the connection groove, and the pole part is arranged inside the shell; The pole comprises an extension portion and a first connection portion connected to each other, the extension portion is arranged outside the shell, the first connection portion passes through the shell, and the connection groove is arranged on the first connection portion; The pole lug includes a second connection portion and a ramp connection portion connected to each other, the second connection portion is at least partially arranged in the connection groove, the second connection portion is connected to the first connection portion, and the ramp connection portion is arranged at the end of the pole group facing the pole column.

2. The battery cell according to claim 1, characterized in that: The cross section of the first connection portion is formed into an I-shaped structure, and the cross section of the second connection portion is formed into an L-shaped structure, and the long side of the L-shaped structure is welded to the inner side of the long horizontal side of the I-shaped structure.

3. The battery cell according to claim 1, characterized in that: The electrode group includes a positive terminal and a negative terminal, the positive terminal of the electrode group is connected to the cover plate assembly through an end plate; and / or the negative terminal of the electrode group is connected to the cover plate assembly; The end plate is arranged between the cover plate assembly and the pole group.

4. The battery cell according to claim 1, characterized in that: The cover plate assembly comprises a cover plate body, a first plastic part, a second plastic part, a welding ring and a sealing part, the pole passes through the cover plate body, and the welding ring is sleeved on the extension part; The first plastic part, the sealing part and the second plastic part are all arranged between the first connecting portion and the cover plate body, and the first plastic part, the sealing part and the second plastic part are arranged in sequence from top to bottom.

5. The battery cell according to claim 4, characterized in that: The battery core further includes an explosion-proof valve, which is disposed on the cover plate body or the housing; and / or The battery cell further includes a liquid injection port, and the liquid injection port is arranged on the cover plate body or the shell.

6. The battery cell according to claim 1, characterized in that: The pole lug is connected to the pole via a connecting piece.

7. The battery cell according to claim 1, characterized in that: The battery cell further includes a side plate and an insulating film, wherein the insulating film is arranged on the periphery of the electrode group, and the side plate is arranged between the shell and the insulating film.

8. A battery pack, characterized in that: The battery pack comprises the battery cell according to any one of claims 1 to 7.

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