Battery cell, battery module and battery pack

Abstract

The utility model provides a battery cell, a battery module and a battery pack, and relates to the field of battery cell structures. The battery cell comprises a pole group assembly, the end part of the pole group assembly is provided with a pole lug, and the end part, far away from the pole group assembly, of the pole lug is provided with a connecting piece; the end part, facing the pole group assembly, of the cover plate assembly is provided with a clamping part corresponding to the connecting sheet; and when the cover plate assembly and the pole group assembly are assembled, the clamping parts are correspondingly clamped with the connecting sheets. In this way, the situation that the connecting pieces are bent by the tabs due to the fact that the battery cell is stressed in the production process or the use process can be effectively avoided, the situations that the tab folding space is reduced, the tabs are inversely inserted into the pole group or the tabs are wrinkled and torn and the like can be avoided, and the safety performance of the battery cell in the use process is greatly improved.

Description

Technical Field

[0001] The present application relates to the field of battery cell structures, and in particular to a battery cell, a battery module and a battery pack. Background Art

[0002] In existing square lithium batteries, the cover plate and the shell are usually sealed by welding to encapsulate the electrode group inside. The electrode group is connected to the positive electrode connecting plate and the negative electrode connecting plate through the positive electrode ear and the negative electrode ear respectively, and then the positive electrode connecting plate and the negative electrode connecting plate are respectively welded to the positive electrode column and the negative electrode column of the cover plate to ensure the use function of the battery cell.

[0003] However, the connection method of directly welding the connecting piece to the pole of the cover plate in the existing battery cell has poor stability, and the battery cell will be subjected to stress during the production process or use, which will cause the pole ear to easily bend the connecting piece connected to it, thereby causing the folded pole ear space (that is, the height space between the connecting piece and the corresponding pole ear welding surface and the pole ear root) to shrink. This makes the battery cell have the risk of the pole ear being inserted upside down into the pole group or wrinkled and torn, which may cause a short circuit inside the battery cell and affect the safe use of the battery cell. Utility Model Content

[0004] In view of this, the purpose of the present application is to provide a battery cell, a battery module and a battery pack to solve the problem that the direct welding connection method between the connecting plate and the cover plate in the existing battery cell has poor stability and affects the safety of the battery cell.

[0005] According to the above purpose, the first aspect of the present utility model provides a battery cell, wherein the battery cell comprises:

[0006] A pole group assembly, wherein a pole lug is disposed at an end of the pole group assembly, and a connecting piece is disposed at an end of the pole lug away from the pole group assembly; and

[0007] A cover plate assembly, wherein the end of the cover plate assembly facing the pole group assembly is provided with a snap-in portion corresponding to the connecting piece; when the cover plate assembly is assembled with the pole group assembly, the snap-in portion is snap-fitted with the connecting piece accordingly.

[0008] Preferably, the electrode tabs include a positive electrode tab and a negative electrode tab, the connecting pieces include a positive electrode connecting piece and a negative electrode connecting piece respectively connected to the positive electrode tab and the negative electrode tab; the clamping portion includes a first sub-clamping portion and a second sub-clamping portion respectively corresponding to the positive electrode connecting piece and the negative electrode connecting piece.

[0009] Preferably, the cover plate assembly is provided with a positive electrode column and a negative electrode column; the positive electrode connecting piece is formed with a positive electrode column connecting section and a positive electrode ear connecting section connected in sequence, and the negative electrode connecting piece is formed with a negative electrode column connecting section and a negative electrode ear connecting section connected in sequence;

[0010] When the cover plate assembly is assembled with the electrode group assembly, the first sub-clamping portion is correspondingly engaged with the positive electrode ear connecting section, and the second sub-clamping portion is correspondingly engaged with the negative electrode ear connecting section.

[0011] Preferably, the first sub-clamping portion and the second sub-clamping portion respectively include a plurality of buckles formed into a quasi-L-shaped structure;

[0012] Along the forming direction of the positive electrode connecting sheet, the buckles are respectively engaged with the two ends of the positive electrode ear connecting section in the extending direction; along the forming direction of the negative electrode connecting sheet, the buckles are respectively engaged with the two ends of the negative electrode ear connecting section in the extending direction.

[0013] Preferably, the vertical section of each of the buckles is connected to the cover plate assembly; the thickness of the vertical section of the buckle is not less than 0.3 mm and not more than 2 mm; and / or the width of the buckle is not less than 1.5 mm.

[0014] Preferably, when the clamping portion is correspondingly engaged with the connecting piece, the positive ear connecting segment and the negative ear connecting segment are respectively abutted against the corresponding horizontal segment of the buckle, and the spacing between the positive ear connecting segment and the negative ear connecting segment and the corresponding vertical segment of the buckle is not less than 0 mm, and / or the overlapping length of the positive ear connecting segment and the negative ear connecting segment is not less than 0.3 mm and not more than 5 mm.

[0015] Preferably, an inclined introduction surface is formed at the end of the horizontal section of the buckle away from the vertical section, and the angle between the introduction surface and the vertical plane is not less than 5°.

[0016] Preferably, a baffle is provided on the side of the end of the cover plate assembly facing the pole group assembly, so that the cover plate assembly is formed into a groove-shaped structure opening toward the pole group assembly, and the clamping portion is located at the bottom of the groove-shaped structure;

[0017] When the clamping portion is correspondingly engaged with the connecting piece, the distances between the ends of the positive electrode tab connecting section and the negative electrode tab connecting section in the width direction and the corresponding inner walls of the groove-shaped structure are no greater than 1 mm.

[0018] According to a second aspect of the present invention, a battery module is provided, wherein the battery module comprises the battery cell as described above.

[0019] According to a third aspect of the present invention, a battery pack is provided, wherein the battery pack is provided with the battery module as described above.

[0020] According to the battery cell, battery module and battery pack of the utility model, the pole group assembly is provided with correspondingly connected pole groups, pole ears and connecting plates. In addition, a clamping portion corresponding to the connecting plate is provided at the end of the cover plate assembly facing the pole group assembly, so that when the cover plate assembly and the pole group assembly are assembled, the connecting plate can first be preliminarily clamped and fixed with the cover plate assembly through the clamping portion, and then it can be welded to the corresponding pole column by welding.

[0021] Compared with the existing battery cell structure, the battery cell in the utility model can facilitate the positioning of the connecting piece during the assembly process through the clamping part, and can also increase the stability of the connection of the connecting piece, thereby effectively avoiding the situation where the battery cell is subjected to force during the production process or use, causing the pole ear to bend the connecting piece, and further avoiding the occurrence of situations such as the reduction of the folded pole ear space, the pole ear being inserted upside down into the pole group, or wrinkles and tearing, thereby greatly increasing the safety performance of the battery cell when in use.

[0022] 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

[0023] 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 certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 is an exploded view of a battery cell according to an embodiment of the utility model;

[0025] Figure 2 is a schematic diagram of the connecting piece and the clamping portion when they are engaged according to an embodiment of the utility model;

[0026] Figure 3 is a cross-sectional view of a battery cell according to an embodiment of the utility model;

[0027] Figure 4 is an enlarged schematic diagram of point A according to an embodiment of the utility model;

[0028] Figure 5 is an enlarged schematic diagram of point B according to an embodiment of the utility model;

[0029] Figure 6 It is an enlarged schematic diagram of point C according to an embodiment of the utility model.

[0030] Icons: 1-pole group assembly; 10-housing; 11-pole group; 20-positive electrode ear; 21-negative electrode ear; 30-positive electrode connecting piece; 300-positive electrode column connecting section; 301-positive electrode ear connecting section; 31-negative electrode connecting piece; 310-negative electrode column connecting section; 311-negative electrode ear connecting section; 4-cover plate assembly; 40-positive electrode column; 41-negative electrode column; 420-first sub-clamping portion; 421-second sub-clamping portion; 422-buckle. DETAILED DESCRIPTION

[0031] 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.

[0032] 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.

[0033] 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.

[0034] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] like Figures 1 to 6As shown, according to the first aspect of the utility model, a battery cell is provided, which includes a pole group assembly 1 and a cover plate assembly 4, and a clamping portion is provided at the end of the cover plate assembly 4 facing the pole group assembly 1; when the cover plate assembly 4 is assembled with the pole group assembly 1, the clamping portion is correspondingly engaged with the following connecting piece, so as to increase the stability of the connecting piece (including the positive connecting piece 30 and the negative connecting piece 31) when connected with the cover plate assembly 4, thereby increasing the stability of the overall structure of the battery cell and the safety of use. In the following, the specific structure of the above-mentioned parts of the battery cell according to the utility model will be described in detail.

[0041] The pole group assembly 1 includes a housing 10 and a pole group 11 disposed inside the housing 10. The end of the pole group 11 is provided with a pole ear (such as Figure 1 and Figure 3 As shown, the pole ear in this embodiment is located at the top of the pole group 11 in the height direction), and a connecting piece is provided at the top of the pole ear away from the pole group assembly 1; in addition, the pole group 11, the pole ear and the connecting piece are welded in sequence. Further, the pole ear includes a positive pole ear 20 and a negative pole ear 21, and the connecting piece includes a positive pole connecting piece 30 and a negative pole connecting piece 31 respectively connected to the positive pole ear 20 and the negative pole ear 21, and the above-mentioned clamping part includes a first sub-clamping part 420 and a second sub-clamping part 421 respectively corresponding to the positive pole connecting piece 30 and the negative pole connecting piece 31.

[0042] It should be noted that the connection method and the arrangement position of the electrode group 11, the two electrode ears and the two connecting pieces are all conventional arrangements of existing battery cells, and therefore will not be described in detail. Figure 1 and Figure 3 As shown, the positive electrode ear 20 and the negative electrode ear 21 in this embodiment are both arranged at the top of the electrode group 11 (that is, the positive electrode ear 20 and the negative electrode ear 21 are located on the same side of the electrode group 11), so the first sub-clamping portion 420 and the second sub-clamping portion 421 are correspondingly located at the end of the same cover plate assembly 4. However, it is not limited to this, when the positive electrode ear 20 and the negative electrode ear 21 are respectively arranged at the two ends (for example, the top end and the bottom end) of the electrode group 11, the first sub-clamping portion 420 and the second sub-clamping portion 421 are respectively correspondingly located at the ends of different cover plate assemblies 4.

[0043] In addition, if Figures 1 to 4As shown, in this embodiment, the two ends of the cover plate assembly 4 in the length direction are respectively provided with a positive pole column 40 and a negative pole column 41 (this structure is also an existing structure); further, the positive electrode connecting sheet 30 is formed with a positive pole column connecting section 300 and a positive pole ear connecting section 301 connected in sequence, and the positive pole ear connecting section 301 is welded to the positive pole ear 20; the negative pole connecting sheet 31 is formed with a negative pole column connecting section 310 and a negative pole ear connecting section 311 connected in sequence, and the negative pole ear connecting section 311 is welded to the negative pole ear 21. In this way, when the cover plate assembly 4 is assembled with the electrode group assembly 1, the first sub-clamping portion 420 is correspondingly engaged with the positive pole ear connecting section 301, and the second sub-clamping portion 421 is correspondingly engaged with the negative pole ear connecting section 311, and then the positive pole column connecting section 300 and the negative pole column connecting section 310 are respectively connected to the positive pole column 40 and the negative pole column 41 by welding.

[0044] Specifically, Figures 1 to 4 As shown, the first sub-clamping portion 420 and the second sub-clamping portion 421 respectively include a plurality of buckles 422, and along the formation direction of the positive electrode connecting sheet 30 (i.e., the length direction of the cover plate assembly 4), the buckles 422 are respectively clamped with the two ends of the extension direction of the positive electrode ear connecting section 301, that is, the first sub-clamping portion 420 can play a role of limiting and fixing in the length direction of the positive electrode connecting sheet 30. Similarly, along the formation direction of the negative electrode connecting sheet 31 (i.e., the length direction of the cover plate assembly 4), the buckles 422 are respectively clamped with the two ends of the extension direction of the negative electrode ear connecting section 311, that is, the second sub-clamping portion 421 can play a role of limiting and fixing in the length direction of the negative electrode connecting sheet 31.

[0045] It should be noted that there is no specific limit on the number of clips 422, but the clips 422 should be arranged in pairs to ensure their snap-on effect; in addition, there is no specific limit on the connection position of each clip 422 and the cover assembly 4, and it should be determined based on actual conditions such as the structure and size of the positive electrode connecting plate 30 and the negative electrode connecting plate 31, and the width of the positive electrode ear 20 and the negative electrode ear 21 (the spacing between each pair of clips 422 needs to be greater than the width of the ear to avoid interference with the ear and crushing the ear during snap-on), as long as the above-mentioned technical effects can be achieved.

[0046] More specifically, the buckle 422 in this embodiment is formed into a quasi-L-shaped structure, and the vertical section of each buckle 422 is fixedly connected to the cover plate assembly 4 away from the end surface of the horizontal section, and the horizontal section of each buckle 422 can be engaged with the corresponding positive electrode connecting piece 30 or the corresponding negative electrode connecting piece 31. In order to ensure the connection strength and connection rigidity of the buckle 422, and to facilitate the buckle 422 to rebound without breaking, the width of the buckle 422 should be not less than 1.5 mm; in addition, if Figure 5 As shown, the thickness of the vertical segment of each buckle 422 is not less than 0.3 mm and not more than 2 mm (ie, 0.3 mm≤a≤2 mm).

[0047] In addition, if Figures 4 to 5 As shown, when the clamping portion is correspondingly engaged with the connecting piece, the above-mentioned positive ear connecting segment 301 and the above-mentioned negative ear connecting segment 311 are respectively abutted against the top segment of the horizontal segment of the corresponding buckle 422, and the spacing between the positive ear connecting segment 301 and the negative ear connecting segment 311 and the vertical segment of the corresponding buckle 422 is not less than 0mm (that is, b≥0mm); the overlapping length of the positive ear connecting segment 301 and the negative ear connecting segment 311 (and the corresponding buckle 422) is not less than 0.3mm and not more than 5mm (that is, 0.3mm≤c≤5mm), so as to avoid the positive electrode connecting piece 30 and the negative electrode connecting piece 31 from falling out due to insufficient overlapping length, or the positive electrode connecting piece 30 and the negative electrode connecting piece 31 cannot be normally inserted due to excessive overlapping length.

[0048] Furthermore, if Figure 5 As shown, the top of the horizontal section of the buckle 422 in this embodiment is formed as an inclined surface, and the interference between the positive connecting piece 30 and the negative connecting piece 31 and the corresponding clamping node of the buckle 422 is not greater than 2mm (i.e., d≤2mm) to prevent the positive connecting piece 30 and the negative connecting piece 31 from being unable to be normally inserted; in addition, an inclined introduction surface is formed at the end of the horizontal section of the buckle 422 away from the vertical section, and the angle between the introduction surface and the vertical plane is not less than 5° (i.e., e≥5°) to further improve the smoothness of the insertion of the positive connecting piece 30 and the negative connecting piece 31.

[0049] In addition, if Figure 1 to Figure 2 As shown, a baffle is provided on the side of the end of the cover plate assembly 4 facing the electrode group assembly 1, so that the cover plate assembly 4 forms a groove-shaped structure opening toward the electrode group assembly 1, and the above-mentioned clamping portion is located at the bottom of the groove-shaped structure; when the clamping portion is correspondingly engaged with the connecting piece, the distance between the ends of the positive ear connecting section 301 and the negative ear connecting section 311 in the width direction and the corresponding inner wall of the groove-shaped structure is not greater than 1 mm (i.e., Figure 6 As shown, f≤1mm), so that the positive electrode connecting sheet 30 and the negative electrode connecting sheet 31 can be limited and fixed in the width direction, so as to facilitate the assembly and production of the entire battery cell.

[0050] According to the battery cell of the utility model, the pole group assembly 1 is provided with a correspondingly connected pole group 11, pole ears and connecting pieces. In addition, a clamping portion corresponding to the connecting piece is provided at the end of the cover plate assembly 4 facing the pole group assembly 1, so that when the cover plate assembly 4 is assembled with the pole group assembly 1, the connecting piece can be initially clamped and fixed with the cover plate assembly 4 by the clamping portion, and then welded to the pole column by welding. In this way, the clamping portion can facilitate the positioning of the connecting piece during the assembly process, and can also increase the stability of the connection of the connecting piece, so as to effectively avoid the situation that the pole ears bend the connecting piece due to the force applied to the battery cell during the production process or the use process, and thus can avoid the situation that the folded pole ear space is reduced, the pole ear is inserted inverted into the pole group 11, or the wrinkles and tearing occur, which greatly increases the safety performance of the battery cell when in use.

[0051] According to a second aspect of the present invention, a battery module is provided, the battery module comprising the battery cell as described above.

[0052] According to a third aspect of the present invention, a battery pack is provided, wherein the battery pack is provided with the battery module as described above.

[0053] 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 assembly, wherein a pole lug is disposed at an end of the pole group assembly, and a connecting piece is disposed at an end of the pole lug away from the pole group assembly; and A cover plate assembly, wherein the end of the cover plate assembly facing the pole group assembly is provided with a snap-in portion corresponding to the connecting piece; when the cover plate assembly is assembled with the pole group assembly, the snap-in portion is snap-fitted with the connecting piece accordingly.

2. The battery cell according to claim 1, characterized in that: The electrode tabs include a positive electrode tab and a negative electrode tab, the connecting pieces include a positive electrode connecting piece and a negative electrode connecting piece respectively connected to the positive electrode tab and the negative electrode tab; the clamping portion includes a first sub-clamping portion and a second sub-clamping portion respectively corresponding to the positive electrode connecting piece and the negative electrode connecting piece.

3. The battery cell according to claim 2, characterized in that: The cover plate assembly is provided with a positive electrode column and a negative electrode column; the positive electrode connecting piece is formed with a positive electrode column connecting section and a positive electrode ear connecting section connected in sequence, and the negative electrode connecting piece is formed with a negative electrode column connecting section and a negative electrode ear connecting section connected in sequence; When the cover plate assembly is assembled with the electrode group assembly, the first sub-clamping portion is correspondingly engaged with the positive electrode ear connecting section, and the second sub-clamping portion is correspondingly engaged with the negative electrode ear connecting section.

4. The battery cell according to claim 3, characterized in that: The first sub-clamping portion and the second sub-clamping portion respectively include a plurality of buckles formed into a quasi-L-shaped structure; Along the forming direction of the positive electrode connecting sheet, the buckles are respectively engaged with the two ends of the positive electrode ear connecting section in the extending direction; along the forming direction of the negative electrode connecting sheet, the buckles are respectively engaged with the two ends of the negative electrode ear connecting section in the extending direction.

5. The battery cell according to claim 4, characterized in that: The vertical section of each of the buckles is connected to the cover plate assembly; the thickness of the vertical section of the buckle is not less than 0.3 mm and not more than 2 mm; and / or the width of the buckle is not less than 1.5 mm.

6. The battery cell according to claim 4, characterized in that: When the clamping portion is correspondingly engaged with the connecting piece, the positive ear connecting segment and the negative ear connecting segment are respectively abutted against the corresponding horizontal segments of the buckle, and the spacing between the positive ear connecting segment and the negative ear connecting segment and the corresponding vertical segments of the buckle is not less than 0 mm, and / or the overlapping length of the positive ear connecting segment and the negative ear connecting segment is not less than 0.3 mm and not more than 5 mm.

7. The battery cell according to claim 6, characterized in that: An inclined introduction surface is formed at the end of the horizontal section of the buckle away from the vertical section of the buckle, and the angle between the introduction surface and the vertical plane is not less than 5°.

8. The battery cell according to claim 4, characterized in that: A baffle is provided on the side of the end of the cover plate assembly facing the pole group assembly, so that the cover plate assembly is formed into a groove-shaped structure opening toward the pole group assembly, and the clamping portion is located at the bottom of the groove-shaped structure; When the clamping portion is correspondingly engaged with the connecting piece, the distances between the ends of the positive electrode tab connecting section and the negative electrode tab connecting section in the width direction and the corresponding inner walls of the groove-shaped structure are no greater than 1 mm.

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

10. A battery pack, characterized in that: The battery pack is provided with the battery module as claimed in claim 9.

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