Single battery and battery pack

Abstract

The utility model relates to a single battery and a battery pack. The single battery comprises a cover body assembly, a battery cell assembly and a plate. The cover body assembly comprises a top cover and a pole arranged on the top cover, and the pole is provided with a connecting surface; the battery cell assembly comprises a main body and a tab bundle connected to the edge of the main body, and the tab bundle is fixedly connected to the connecting surface; and the plate is pressed on one side, deviating from the connecting surface, of the tab bundle. The top cover has a length direction and a width direction, and the rotating axis is parallel to the length direction when the battery core assembly is closed. The plate comprises a flat plate part and an extrusion part, the extrusion part is connected to at least one end of the flat plate part in the width direction, and the extrusion part extends towards the direction of the pole relative to the flat plate part. According to the scheme, reliable limiting constraint can be given to the tab bundle when the battery main body is subjected to core combination, bending stress borne by the tab bundle during core combination is reduced, deformation of the tab bundle during battery core combination is reduced, and finally the risk that a single tab in the tab bundle cracks and is inserted into the battery core is reduced.

Description

Technical Field

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

[0002] Batteries are core products in the new energy field and currently have a relatively mature production and manufacturing process. The electrical connection between the tabs and the poles in the battery cell production process is a key technology that affects the quality of the battery cell.

[0003] At present, the tabs and poles are usually connected by welding: first, stack multiple layers of tabs and pre-weld them together to form a tab bundle, and then fit the tab bundle on the welding surface of the pole for welding. After welding, the battery cell is assembled, and the tab bundle usually has a certain length, the purpose of which is to leave enough welding margin for welding. Therefore, when the battery cell is assembled, the tab is subjected to stress along the bending direction, and the redundant part bends inward under the action of stress, which may cause the tab to be inserted into the winding core and contact the positive and negative electrodes, resulting in risks such as short circuits. This problem has always been a problem encountered in the process of assembling battery cells.

[0004] In the prior art, a protective plate is pressed on the side of the tab bundle away from the pole during welding. The clamping between the protective plate and the pole can limit the tab bundle to a certain extent, thereby reducing the situation of tab insertion.

[0005] However, this clamping method utilizes a plane to clamp the tab bundle, and the limiting effect is not good enough, resulting in limited effect in preventing the tab from being inserted. Utility Model Content

[0006] The present application provides a battery and a battery pack to solve the current technical problem of the tab being inserted into the winding core when the battery cell is assembled, so as to improve the yield rate of battery cell production.

[0007] A single cell battery, comprising:

[0008] A cover assembly, the cover assembly comprising a top cover and a pole arranged on the top cover, the pole having a connection surface;

[0009] A battery cell assembly, the battery cell assembly comprising a main body and a tab bundle connected to an edge of the main body, the tab bundle being fixedly connected to the connection surface;

[0010] A plate, the plate being pressed onto a side of the tab bundle facing away from the connection surface;

[0011] The top cover has a length direction and a width direction;

[0012] The plate member includes a flat plate portion and an extrusion portion, wherein the extrusion portion is connected to at least one end of the flat plate portion in the width direction, and the extrusion portion extends toward a direction where the pole is located compared to the flat plate portion.

[0013] To implement the above technical solution, since the extrusion portion extends toward the connecting surface compared to the flat plate portion, after the plate welding is completed, compared with the case where the tab bundle is crimped on the flat surface of the flat plate portion, the extrusion portion can give the tab bundle a larger abutting force, thereby providing better limiting constraints on the bent portion of the tab bundle when the core is closed, so that the tab bundle can be better gathered and constrained together at the bent portion when the core is closed, reducing the bending stress on the tab bundle when the core is closed, thereby reducing the deformation of the tab bundle when the battery cell is closed, and ultimately reducing the risk of a single tab in the tab bundle cracking or being inserted into the battery cell.

[0014] As one of the optional embodiments of the present solution, the orthographic projection of the extrusion portion on the plane where the connecting surface is located is located within the area defined by the connecting surface.

[0015] As one of the optional embodiments of this solution, the area of ​​the connecting surface close to the edge is recessed in the direction away from the plate to form an escape space, the extrusion portion is arranged facing the escape space in the direction perpendicular to the connecting surface, and the tab bundle is partially accommodated in the escape space.

[0016] To implement the above technical solution, when the battery cells are assembled, it is mainly the portion of the tab bundle close to the extrusion portion that bends. It is precisely because of this partial bending that the bending stress is mainly affected on a single tab in the tab bundle. The setting of the avoidance space can partially accommodate the bent portion of the tab bundle in the avoidance space, thereby reducing the bending stress on a single tab and further reducing the possibility of tab tearing or inset.

[0017] As one of the optional embodiments of this solution, the connecting surface includes a central plane, a first surface and a second surface, the first surface and the second surface are located on at least one side of the central plane in the width direction, and the central plane is connected to the second surface through the first surface;

[0018] Wherein, the edge where the first surface is adjacent to the second surface is arranged away from the tab bundle relative to the central plane, and the edge where the second surface is adjacent to the first surface is arranged away from the tab bundle relative to the central plane;

[0019] The avoidance space is formed between the first surface and the second surface.

[0020] As one of the optional embodiments of this solution, the edge of the second surface away from the central plane is a curved surface.

[0021] To implement the above technical solution, since the edge of the second surface contacts the side of the tab bundle close to the connection surface, setting the contact portion as an arc surface can reduce the damage of the pole to the tab bundle, further ensuring the performance of the tab bundle.

[0022] As one of the optional embodiments of the present scheme, the pole includes a base portion and a gathering portion, the side of the base portion facing the plate is the connecting surface, the gathering portion is connected to at least one end of the base portion in the width direction, and the gathering portion extends in the direction of the plate compared to the base portion.

[0023] To implement the above technical solution, the extrusion portion limits the pole lug bundle from the top of the pole lug bundle away from the connecting surface, and the gathering portion limits the pole lug bundle from the bottom of the pole lug bundle close to the connecting surface. The cooperation between the two can provide better limiting constraints on the pole lug bundle, thereby reducing the tendency of bending of a single pole lug in the pole lug bundle and reducing the incidence of pole lug insertion and pole lug tearing.

[0024] As one of the optional embodiments of the present solution, the extrusion portion is arranged on a side of the gathering portion that is away from the connecting surface in the width direction.

[0025] As one of the optional embodiments of this solution, the extrusion portion has a contact surface that contacts the tab bundle, and the contact surface is an arc-shaped surface.

[0026] As one of the optional embodiments of this solution, the flat plate portion has a crimping surface facing the tab bundle, and the single battery cell further includes a bridging member, and the bridging member is fixedly connected to the crimping surface and the connecting surface respectively.

[0027] To implement the above technical solution, the flat plate is crimped onto the surface of the tab bundle before welding, the contact area between the bridge and the tab bundle is small, the local resistance is small, and the current intensity is large when resistance welding is used, which is more conducive to the formation of the molten core and further facilitates smooth welding.

[0028] As one of the optional embodiments of this solution, one end of the bridging member passes through the tab bundle and is connected to the crimping surface or the connecting surface.

[0029] On the other hand, the present application also discloses a battery pack, which includes:

[0030] a housing; and,

[0031] A single cell battery is housed in the box.

[0032] One of the above technical solutions has the following advantages or beneficial effects:

[0033] 1. Compared with the flat plate portion, the extruded portion extends toward the connecting surface. After the plate is welded, compared with the case where the tab bundle is crimped on the flat surface of the flat plate portion, the extruded portion can give the tab bundle a larger abutting force and pull the tab bundle toward the pole column, thereby providing better limiting constraints on the bent portion of the tab bundle when the core is closed, so that the tab bundle can be better gathered and constrained together at the bent portion of the core, reducing the bending stress on the tab bundle when the core is closed, thereby reducing the deformation of the tab bundle when the battery cell is closed, and finally reducing the risk of a single tab in the tab bundle cracking and being inserted into the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0035] Figure 1 is a cross-sectional view provided in Example 1 of the present application for illustrating the matching relationship between the plate and the pole;

[0036] Figure 2 It is a top view provided in Example 1 of the present application for showing the positional relationship between the plate and the pole;

[0037] Figure 3 This is provided in Example 1 of the present application Figure 1 A partial enlarged view of part A;

[0038] Figure 4 It is a schematic diagram provided in Example 1 of the present application and mainly used to show the connection surface structure;

[0039] Figure 5 is a cross-sectional view of an embodiment of a pole including a gathered portion provided in Embodiment 1 of the present application;

[0040] Figure 6 It is a cross-sectional view provided in Example 1 of the present application and mainly used to show the structure of the panel;

[0041] Figure 7 This is a top view of another embodiment of the panel provided in Example 1 of the present application.

[0042] Reference numerals: 1, cover assembly; 11, top cover; 12, pole; 12a, base portion; 12b, gathering portion; 121, connection surface; 1211, center plane; 1212, first surface; 1213, second surface;

[0043] 2. Battery cell assembly; 21. Main body; 22. Tab bundle;

[0044] 3. Plate; 31. Flat plate portion; 311. Pressing surface; 32. Extrusion portion; 321. Contact surface;

[0045] 4. Avoidance space;

[0046] 5. Bridge piece;

[0047] X, width direction; Y, length direction. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0049] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article, unless otherwise specified, generally indicates that the associated objects before and after are in an "or" relationship.

[0050] The following is combined with Figure 1-7 The present application is further described.

[0051] Reference Figure 1 and Figure 2 , is a single cell battery disclosed in the present application, which includes a cover assembly 1, a battery cell assembly 2 and a plate 3. The cover assembly 1 includes a top cover 11 and a pole 12 arranged on the top cover 11, the top cover 11 has a length direction Y and a width direction X, and the pole 12 has a connection surface 121. The battery cell assembly 2 includes a main body 21 and a tab bundle 22 connected to the edge of the main body 21, the battery cell assembly 2 is provided with two and is respectively located on both sides of the length direction Y of the top cover 11, and the tab bundles 22 on the two main bodies 21 are fixedly connected to the connection surface 121. In this embodiment, the tab bundle 22 is fixed to the connection surface 121 by resistance welding. In other optional embodiments, the tab bundle 22 can also be fixed to the connection surface 121 by at least one of other fixing methods such as laser welding or ultrasonic welding to achieve a stable electrical connection. The plate 3 is pressed on the side of the tab bundle 22 away from the connection surface 121.

[0052] It should be noted that Figure 1 The plate 3 shown in the figure has not been welded and fixed on the connecting surface 121, and the core has not been closed at this time. When the battery cell assembly 2 is closed, the rotation axis of the main body 21 is parallel to the length direction Y. When the core needs to be closed, the two main bodies 21 are rotated around the length direction Y to approach each other to complete the process of closing the core, and finally installed in the battery shell, and after sealing welding, the top cover is welded to the battery shell, so that the battery cell assembly 2 is sealed in the battery shell.

[0053] Reference Figure 1 and Figure 3 The plate 3 includes a flat plate portion 31 and an extrusion portion 32. The two opposite surfaces of the flat plate portion 31 in the thickness direction are both planes and are parallel to the connection surface 121. The extrusion portion 32 is connected to at least one end of the flat plate portion 31 in the width direction X. In this embodiment, the extrusion portion 32 is arranged at both ends of the flat plate portion 31 in the width direction X. The extrusion portion 32 extends in the direction toward the pole 12 compared to the flat plate portion 31. Since the extrusion portion 32 extends toward the connection surface 121 compared to the flat plate portion 31, the extrusion portion 32 can give the tab bundle 22 a greater abutment force than the flat plate portion 31 crimping the tab bundle 22 in a plane, so that when the main body 21 is flipped over to close the core, the bent portion of the tab bundle 22 can be better limited and restrained together, so that the bent portion of the tab bundle 22 is better gathered and restrained together when the core is closed, reducing the bending stress on the tab bundle 22 when the core is closed, thereby reducing the deformation of the tab bundle 22 when the battery cell is closed, and finally reducing the risk of a single tab in the tab bundle 22 cracking or being inserted into the main body 21. The extrusion portion 32 has a contact surface 321 that contacts the tab bundle 22, and the contact surface 321 is an arc surface to reduce the extrusion damage of the extrusion portion 32 to the tab bundle 22, and when the plate 3 is cut along the axial direction of the pole 12, the arc line obtained by cutting the arc surface is a major arc convex to the connection surface 121.

[0054] It should be noted that the extrusion portion 32 is not necessarily a continuous whole along the length direction Y. For example Figure 7 In the illustrated plate 3, the extrusion portion 32 on the left side of the main body 21 may also be arranged on the main body 21 of the plate 3 at intervals along the length direction Y. In addition, in this embodiment, the extrusion portion 32 is generally arc-shaped, and in the direction in which the two extrusion portions 32 move away from each other along the width direction X, the extrusion portion 32 gradually extends closer to the pole 12. In other optional embodiments, the extrusion portion 32 may also directly extend in a direction perpendicular to the connection surface 121.

[0055] Reference Figure 1 and Figure 3, the orthographic projection of the extrusion portion 32 on the plane where the connection surface 121 is located is located within the area defined by the connection surface 121. The area near the edge of the connection surface 121 is recessed in the direction away from the plate 3 to form an escape space 4, and the end of the extrusion portion 32 away from the flat plate portion 31 is arranged facing the escape space 4 in a direction perpendicular to the connection surface 121, and the tab bundle 22 is partially accommodated in the escape space 4. When the battery cell is assembled, it is mainly the part of the tab bundle 22 close to the extrusion portion 32 that is bent. It is precisely because of this partial bending that the bending stress of a single tab in the tab bundle 22 is mainly affected. The above setting of the escape space 4 can make the bent part of the tab bundle 22 partially accommodated in the escape space 4, thereby reducing the bending stress of a single tab, thereby reducing the tab tearing and reducing the insertion into the main body 21.

[0056] It should be noted that, in other optional embodiments, the orthographic projection of the extrusion portion 32 on the plane where the connecting surface 121 is located may also be located outside the area defined by the connecting surface 121, for example Figure 5 However, since the flipping of the main body 21 during the core closing cannot allow part of the tab bundle 22 to be accommodated in the escape space 4, it is more appropriate to cancel the design of the escape space 4 at this time.

[0057] Reference Figure 1 and Figure 4 The connecting surface 121 includes a central plane 1211, a first surface 1212 and a second surface 1213. The first surface 1212 and the second surface 1213 are located on at least one side of the central plane 1211 in the width direction X. The central plane 1211 is connected to the second surface 1213 through the first surface 1212. In this embodiment, two groups of first surfaces 1212 and second surfaces 1213 are provided, and are respectively provided on both sides of the central plane 1211 in the width direction X. Among them, the edge adjacent to the first surface 1212 and the second surface 1213 is arranged away from the tab bundle 22 relative to the central plane 1211, and the edge adjacent to the second surface 1213 and the first surface 1212 is arranged away from the tab bundle 22 relative to the central plane 1211; and an avoidance space 4 is formed between the first surface 1212 and the second surface 1213. Among them, the edge of the second surface 1213 away from the center plane 1211 is an arc surface, and the edge of the second surface 1213 contacts the side of the pole lug bundle 22 close to the connecting surface 121. Setting the contact part as an arc surface can reduce the damage of the pole 12 to the pole lug bundle 22, and further ensure the performance of the pole lug bundle 22.

[0058] It should be noted that, in this embodiment, the first surface 1212 and the second surface 1213 are both inclined planes. Figure 4 As shown in FIG. 1 , both the first surface 1212 and the second surface 1213 are inclined in a direction away from the connecting surface 121. In other optional embodiments, the first surface 1212 and the second surface 1213 are curved surfaces or arc surfaces.

[0059] Reference Figure 1 and Figure 5 The pole 12 includes a base portion 12a and a gathering portion 12b. The side of the base portion 12a facing the plate 3 is the aforementioned connection surface 121. The gathering portion 12b is connected to at least one end of the base portion 12a in the width direction X. The gathering portion 12b extends in the direction of the plate 3 compared to the base portion 12a. In this embodiment, two gathering portions 12b are provided and are respectively located at the two ends of the body 21 in the width direction X. The extrusion portion 32 limits the pole lug bundle 22 from the top of the pole lug bundle 22 away from the connection surface 121, and the gathering portion 12b limits the pole lug bundle 22 from the bottom of the pole lug bundle 22 close to the connection surface 121. The cooperation between the two can provide better limiting constraints to the pole lug bundle 22, thereby reducing the tendency of bending of a single pole lug in the pole lug bundle 22, and reducing the situation of pole lug insertion and pole lug tearing. In this embodiment, the extrusion portion 32 is arranged on the side of the gathering portion 12b that is away from the connection surface 121 in the width direction X, which is conducive to effectively constraining the tab bundle 22, so that the tabs in the tab bundle 22 are arranged more neatly, and the tabs in the tab bundle 22 are reduced from being loosened and interpolated when the core is closed. In other optional embodiments, the extrusion portion 32 and the gathering portion 12b are arranged facing each other in the direction perpendicular to the connection surface 121.

[0060] Reference Figure 1 and Figure 6 The flat plate portion 31 has a crimping surface 311 facing the tab bundle 22, and the crimping surface 311 is a plane parallel to the connecting surface 121. The single battery further includes a bridge 5, and the bridge 5 is fixedly connected to the crimping surface 311 and the connecting surface 121 respectively. Figure 1 and Figure 6 The structure of the plate 3 before welding is shown in FIG. 1 , in which the bridge 5 is formed by a protrusion on the crimping surface 311 facing the connecting surface 121. This setting is due to the small contact surface 321 between the protrusion and the tab bundle 22, the small local resistance, and the high current intensity during resistance welding, which is more conducive to the formation of the molten core, and further conducive to the smooth progress of welding. One end of the bridge 5 passes through the tab bundle 22 and is connected to the crimping surface 311 or the connecting surface 121.

[0061] It should be noted that in this embodiment, the end of the protrusion is in the shape of a spike so that it can pierce the tab bundle 22 and contact the connection surface 121 before welding. This setting is because the material of part of the tab bundle 22 includes an insulating substrate and a metal film plated on both sides of the substrate in the thickness direction, and it is difficult to form a melt core by traditional resistance welding. After the end of the protrusion is in the shape of a spike and passes through the tab bundle 22 and contacts the connection surface 121, a smooth current channel can be formed between the protrusion and the connection surface 121, which is conducive to the formation of a melt core during resistance welding. Finally, after the welding is completed, the other end of the protrusion is welded and fixedly connected to the connection surface, and the protrusion becomes a bridge 5 after the product is formed.

[0062] On the other hand, the present application also discloses a battery pack, which includes:

[0063] Box body; single cell battery, multiple single cells are arranged and accommodated in the box body, and multiple single cells are electrically connected.

[0064] The above description is only a partial implementation method of the embodiments of the present application and does not constitute any form of limitation on the application. The protection scope of the embodiments of the present application is not limited thereto. Any simple modifications, equivalent changes and modifications that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the embodiments of the present application should be covered within the protection scope of the embodiments of the present application.

Claims

1. A single cell battery, characterized in that: include: A cover assembly (1), the cover assembly (1) comprising a top cover (11) and a pole (12) arranged on the top cover (11), the pole (12) having a connection surface (121); A battery cell assembly (2), the battery cell assembly (2) comprising a main body (21) and a tab bundle (22) connected to an edge of the main body (21), the tab bundle (22) being fixedly connected to the connection surface (121); A plate member (3), the plate member (3) being pressed onto a side of the tab bundle (22) facing away from the connection surface (121); The top cover (11) has a length direction (Y) and a width direction (X); The plate member (3) comprises a flat plate portion (31) and an extrusion portion (32), wherein the extrusion portion (32) is connected to at least one end of the flat plate portion (31) in the width direction (X), and the extrusion portion (32) extends in a direction toward the pole (12) relative to the flat plate portion (31).

2. The single cell according to claim 1, characterized in that: The orthographic projection of the extrusion portion (32) on the plane where the connecting surface (121) is located is located within the area defined by the connecting surface (121).

3. The single cell according to claim 2, characterized in that: The area near the edge of the connecting surface (121) is recessed in a direction away from the plate (3) to form an escape space (4); the extrusion portion (32) is arranged facing the escape space (4) in a direction perpendicular to the connecting surface (121); and a portion of the tab bundle (22) is accommodated in the escape space (4).

4. The single cell according to claim 3, characterized in that: The connecting surface (121) comprises a central plane (1211), a first surface (1212) and a second surface (1213), wherein the first surface (1212) and the second surface (1213) are located on at least one side of the central plane (1211) in the width direction (X), and the central plane (1211) is connected to the second surface (1213) via the first surface (1212); Wherein, the edge where the first surface (1212) and the second surface (1213) are adjacent is arranged away from the tab bundle (22) relative to the central plane (1211); The avoidance space (4) is formed between the first surface (1212) and the second surface (1213).

5. The single cell according to claim 4, characterized in that: The edge of the second surface (1213) away from the central plane (1211) is a curved surface.

6. The single cell according to claim 1, characterized in that: The pole (12) comprises a base portion (12a) and a gathering portion (12b); a side of the base portion (12a) facing the plate member (3) is the connecting surface (121); the gathering portion (12b) is connected to at least one end of the base portion (12a) in the width direction (X); and the gathering portion (12b) extends in a direction toward the plate member (3) relative to the base portion (12a).

7. The single cell according to claim 6, characterized in that: The extrusion portion (32) is arranged on a side of the gathering portion (12b) that is away from the connecting surface (121) in the width direction (X).

8. The single cell according to any one of claims 1 to 7, characterized in that: The extrusion portion (32) has a contact surface (321) in contact with the tab bundle (22), and the contact surface (321) is an arc-shaped surface.

9. The single cell according to claim 1, characterized in that: The flat plate portion (31) has a crimping surface (311) facing the tab bundle (22), and the single battery further comprises a bridge member (5), wherein the bridge member (5) is respectively fixedly connected to the crimping surface (311) and the connection surface (121).

10. The single cell according to claim 9, characterized in that: One end of the bridge piece (5) passes through the tab bundle (22) and is connected to the crimping surface (311) or the connecting surface (121).

11. A battery pack, characterized in that: include: Box; as well as, The single cell battery according to any one of claims 1 to 10, wherein the single cell battery is accommodated in the box.

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