Battery connecting piece and lithium battery

Abstract

The utility model provides a battery connecting piece and a lithium battery, the battery connecting piece is arranged between a cover plate and a core package, the battery connecting piece comprises a connecting piece body, one side of the connecting piece body facing the cover plate is provided with a convex part, and the convex part is used for being welded with a pole on the cover plate. Welding areas are respectively arranged on the top surface of the connecting piece body on the two sides of the convex part along the width direction of the cover plate, a tab is arranged on the core bag, the tab is positioned between the cover plate and the connecting piece body, and the tab is welded with the welding areas. According to the battery connecting piece disclosed by the utility model, the welding point of the pole lug and the connecting piece and the welding point of the connecting piece and the pole column are positioned on the axis vertical to the width direction of the cover plate, so that the welding between the connecting piece and the pole column and the welding between the connecting piece and the pole lug are positioned on the same straight line; the current can be conducted to the pole from the tab through the connecting piece along the shortest path, so that the path length in current transmission is reduced to a great extent, a bypassing or complicated current flowing path is avoided, and the internal resistance is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery connecting piece and a lithium battery. Background Art

[0002] When assembling a lithium battery, it is necessary to first weld the tab of the rolled core to the cover plate, and then combine the left and right rolled cores and install them into the housing to form a battery. When welding the tab, a connecting piece is usually used as a medium to weld the tab and the cover plate.

[0003] In the prior art, the tab and the connecting piece adopt traditional butterfly welding. The welding surface of the tab is located between the connecting piece and the core package. The welding between the connecting piece and the pole column and the welding between the connecting piece and the tab are not on the same straight line, and the travel distance is relatively long. As a result, the internal current path of the battery is long, the internal resistance increases, and the temperature will rise during the fast charging process, which will affect the safety and performance of the battery. Summary of the Utility Model

[0004] In view of this, the utility model provides a battery connecting piece and a lithium battery to solve the problem that in the existing butterfly welding method, the welding between the connecting piece and the pole column and the welding between the connecting piece and the tab are not on the same straight line, resulting in a long internal current path of the battery and an increase in internal resistance.

[0005] The technical solution of the utility model is realized as follows:

[0006] On the one hand, the utility model provides a battery connecting piece, which is arranged between the cover plate and the core package. The battery connecting piece includes a connecting piece body. One side of the connecting piece body facing the cover plate has a convex portion, and the convex portion is used for welding with the pole column on the cover plate. The top surfaces of the connecting piece body on both sides of the convex portion respectively have welding areas along the width direction of the cover plate. The core package is provided with tabs, and the tabs are located between the cover plate and the connecting piece body and are welded to the welding areas.

[0007] On the basis of the above technical solution, preferably, the convex portion is located at the center of the connecting piece body.

[0008] Preferably, the thickness of the convex portion is greater than or equal to the thickness of the tab.

[0009] Furthermore, preferably, a groove corresponding to the position of the convex portion is opened on the side of the connecting piece body away from the cover plate.

[0010] On the basis of the above technical solution, preferably, the width of the connecting piece body is greater than or equal to the width of the tab.

[0011] On the basis of the above technical solution, preferably, the length of the connecting piece body is less than the width of the cover plate.

[0012] Preferably, a chamfer is provided at the edge of the welding area.

[0013] On the other hand, the present utility model discloses a lithium battery, which includes a housing, two core packages disposed in the housing, and a cover plate connected to the opening of the housing. The battery also includes the battery connection piece described in the first aspect. A tab is provided on the core package, and the tab is welded to the cover plate through the battery connection piece.

[0014] Based on the above technical solution, preferably, the cover plate includes a light aluminum plate, pole columns, and a lower plastic part. There are two pole columns, which are respectively located at both ends in the length direction of the light aluminum plate. The lower plastic part is fixedly disposed on the bottom surface of the light aluminum plate. The battery connection piece is located on the side of the lower plastic part away from the light aluminum plate. The protruding part on the battery connection piece is welded to the pole column passing through the lower plastic part, and there is a receiving space for accommodating the tab between the welding area and the lower plastic part.

[0015] The present utility model has the following beneficial effects compared with the prior art:

[0016] (1) By having welding areas on the top surface of the connection piece body on both sides of the protruding part along the width direction of the cover plate respectively, the protruding part is welded to the pole column, and the welding areas are respectively welded to the tabs. This enables the welding points between the tab and the connection piece and the welding points between the connection piece and the pole column to be on the axis perpendicular to the width direction of the cover plate, thereby realizing the welding between the connection piece and the pole column and the welding between the connection piece and the tab in a straight line. The current can conduct from the tab to the pole column through the connection piece along the shortest path. Such a design greatly reduces the path length in current transmission, avoids detours or complex current flow routes, and reduces the internal resistance. In addition, the shortening of the current path means that the energy transmission efficiency of the battery during operation is improved. Especially during fast charging or high-power output, the reduction of internal resistance can effectively reduce the heating phenomenon and enhance the safety and stability of the battery.

[0017] (2) By making the positions of the protruding part, the welding area, and the pole column on the same straight line, the welding process between the tab and the pole column is simplified, and the operator can more conveniently perform welding positioning. This not only reduces the error during the welding process but also improves the welding consistency, ensuring the consistent performance and quality of all batteries. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1Schematic three-dimensional structure diagram of the battery connecting piece disclosed by the present utility model;

[0020] Figure 2 Schematic three-dimensional assembly structure diagram of the battery connecting piece, the tab and the cover plate disclosed by the present utility model;

[0021] Figure 3 Schematic plan view of the assembly structure of the battery connecting piece, the tab and the cover plate disclosed by the present utility model;

[0022] Figure 4 is Figure 3 Cross-sectional plan view taken along line A-A in

[0023] Figure 5 Explosion diagram of the lithium battery disclosed by the present utility model;

[0024] Figure 6 Schematic plan view of the lithium battery disclosed by the present utility model;

[0025] Figure 7 is Figure 6 Cross-sectional plan view taken along line B-B in

[0026] Reference numerals:

[0027] 100, battery connecting piece; 110, connecting piece body; 120, protruding part; 130, welding area; 140, groove; 200, cover plate; 300, core package; 400, housing; 310, tab; 210, light aluminum plate; 220, pole column; 230, lower plastic part; 231, accommodating space. Detailed implementation manners

[0028] Next, in combination with the embodiments of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0029] As Figure 1 shown, in combination with Figures 2 - 4, an embodiment of the present utility model discloses a battery connecting piece 100, which is used to connect a cover plate 200 and a tab 310. During actual assembly, it is arranged between the cover plate 200 and the core package 300. Specifically, the battery connecting piece 100 of this embodiment includes a connecting piece body 110. The connecting piece body 110 has a sheet-like structure. One side of the connecting piece body 110 facing the cover plate 200 has a convex portion 120, and the convex portion 120 is used to be welded to the pole post 220 on the cover plate 200. On the top surface of the connecting piece body 110 on both sides of the convex portion 120, there are welding areas 130 along the width direction of the cover plate 200. The core package 300 is provided with tabs 310. The tabs 310 are located between the cover plate 200 and the connecting piece body 110, and the tabs 310 are welded to the welding areas 130.

[0030] With the above technical solution, welding areas 130 are arranged along the width direction of the cover plate 200 on both sides of the convex portion 120. The convex portion 120 is welded to the pole post 220, and the welding areas 130 are respectively welded to the tabs 310. This makes the welding points between the tabs 310 and the connecting piece and the welding points between the connecting piece and the pole post 220 on the axis perpendicular to the width direction of the cover plate 200, so as to realize that the welding between the connecting piece and the pole post 220 and the welding between the connecting piece and the tabs 310 are on the same straight line. Current can be conducted from the tabs 310 to the pole post 220 through the connecting piece along the shortest path. Such a design greatly reduces the path length in current transmission, avoids detours or complex current flow routes, and reduces the internal resistance. In addition, the shortening of the current path means that the energy transmission efficiency of the battery during operation is improved. Especially during fast charging or high-power output, the reduction of the internal resistance can effectively reduce the heating phenomenon and improve the safety and stability of the battery.

[0031] As some preferred embodiments, the convex portion 120 is located at the center of the connecting piece body 110, so as to ensure that the welding point between the connecting piece and the pole post 220 is located at the center of the connecting piece. In this way, the areas of the welding areas 130 on both sides of the convex portion 120 are the same, so that the areas after the tabs 310 on the two core packages 300 are respectively welded to the welding areas 130 are the same, ensuring the over-current consistency of the tabs 310.

[0032] As some preferred embodiments, the thickness of the convex portion 120 is greater than or equal to the thickness of the tabs 310. After the tabs are welded on the welding area, the top surface of the tabs is lower than the top surface of the convex portion. This means that during the welding of the connecting piece and the pole post, the convex portion is at a higher position and the tabs are at a relatively lower position. This design of the height difference ensures that during the welding process, the pressure exerted by the connecting piece body towards the cover plate direction does not directly act on the tabs, but is mainly concentrated on the contact point between the convex portion and the pole post, avoiding the risk of deformation or damage to the tabs caused by pressure transmission during the welding process.

[0033] It should also be noted that, in some embodiments, the thickness of the protruding portion is greater than or equal to the thickness of the tab, which forms a gap between the welding area and the cover plate, facilitating the insertion of the tab into the gap to achieve the welding operation between the tab and the welding area.

[0034] It is worth noting that by aligning the positions of the protruding portion 120, the welding area 130, and the terminal post 220 on the same straight line, the welding process between the tab 310 and the terminal post 220 is simplified, and the operator can perform welding positioning more conveniently. This not only reduces errors during the welding process but also improves the welding consistency, ensuring the consistent performance and quality of all batteries.

[0035] When welding the connection piece body 110 and the terminal post 220, it is welded through penetration welding from the bottom surface of the connection piece body 110 to the terminal post 220. Since the protruding portion 120 protrudes from the top surface of the connection piece body 110, the laser welding needs to penetrate through the connection piece body 110 and the protruding portion 120, resulting in a relatively large laser penetration thickness and excessive welding power. Therefore, in this embodiment, a groove 140 corresponding to the position of the protruding portion 120 is provided on the side of the connection piece body 110 away from the cover plate 200. This setting can reduce the welding penetration thickness and lower the power.

[0036] As some preferred embodiments, the width of the connection piece body 110 is greater than or equal to the width of the tab 310. This setting can ensure sufficient welding between the tab 310 and the welding area 130 and improve the current-carrying capacity.

[0037] As some preferred embodiments, the length of the connection piece body 110 is less than the width of the cover plate 200. With this setting, after the tab 310 on the core package 300 is welded to the welding area 130 and then folded, and after the tab 310 bypasses the edge of the connection piece body 110, the tab 310 will not leak outside the cover plate 200 in the horizontal direction, which facilitates the smooth insertion of the cover plate 200 and the core package 300 into the shell after connection.

[0038] As some preferred embodiments, rounded corners are provided at the edge of the welding area 130. Through the setting of the rounded corners, it is possible to avoid scratching the tab 310 at the edge of the connection piece body 110 after folding.

[0039] An embodiment of the present utility model discloses a lithium battery. Referring to the attached Figures 5 - 7 As shown, it includes a housing 400, two core packages 300 disposed in the housing 400, and a cover plate 200 connected to the opening of the housing 400. It also includes the battery connection piece 100 disclosed in the above embodiments. The core package 300 is provided with tabs 310, and the tabs 310 are welded to the cover plate 200 through the battery connection piece 100.

[0040] During the lithium battery assembly process, the battery connection piece 100 can be horizontally arranged on the cover plate 200, and the protrusion 120 on the battery connection piece 100 is aligned with the pole post 220 on the cover plate 200. Through laser welding, the connection between the battery connection piece 100 and the cover plate 200 is completed. Next, the two core packages 300 are horizontally arranged on both sides in the width direction of the cover plate 200, and the tabs 310 of the same polarity of the two core packages 300 are inserted between the battery connection piece 100 and the cover plate 200. Laser welding is performed on the welding area 130 and the tab 310 at the bottom of the battery connection piece 100 to complete the welding of the tab 310 and the battery connection piece 100. When the welding of the tab 310 and the battery connection piece 100 is completed, the two core packages 300 are folded and aligned, and then the operation of inserting the core package 300 into the shell is completed. Finally, the welding of the cover plate 200 and the open end of the shell 400 is achieved.

[0041] Through the setting of the connection piece structure, the welding point between the tab 310 and the connection piece and the welding point between the connection piece and the pole post 220 are on the axis perpendicular to the width direction of the cover plate 200, so as to realize that the welding between the connection piece and the pole post 220 and the welding between the connection piece and the tab 310 are on a straight line. The current can be conducted from the tab 310 to the pole post 220 through the connection piece along the shortest path. Such a design greatly reduces the path length in current transmission, avoids detours or complex current flow routes, and reduces the internal resistance.

[0042] In this embodiment, the cover plate 200 includes a light aluminum plate 210, pole posts 220 and a lower plastic part 230. There are two pole posts 220, which are respectively located at both ends in the length direction of the light aluminum plate 210. The lower plastic part 230 is fixedly arranged on the bottom surface of the light aluminum plate 210. The battery connection piece 100 is located on the side of the lower plastic part 230 away from the light aluminum plate 210. The battery connection piece 100 is insulated from the light aluminum sheet through the lower plastic part 230. The protrusion 120 on the battery connection piece 100 is welded to the pole post 220 passing through the lower plastic part 230. There is an accommodation space 231 for accommodating the tab 310 between the welding area 130 and the lower plastic part 230. With this setting, when the welding of the battery connection piece 100 and the pole post 220 is completed, the tab 310 on the core package 300 can be horizontally inserted into the accommodation space 231 to realize the welding of the tab 310 and the battery connection piece 100.

[0043] The assembly method of the battery connecting piece 100, the tab 310 and the cover plate 200 can also adopt the following method. Specifically, first, the tabs 310 on the two horizontally arranged core packages 300 are respectively welded to the welding area 130 of the battery connecting piece 100. After the welding operation is completed, the core package 300 and the battery connecting piece 100 are integrally covered on the cover plate 200, and the convex portion 120 on the battery connecting piece 100 is made to correspond to the pole column 220, and then the welding operation between the battery connecting piece 100 and the pole column 220 is completed. Since the top surface of the convex portion 120 is higher than the welding area 130, the accommodating space 231 formed between the welding area 130 and the lower plastic part 230 can accommodate the tab 310. After the tab 310 is welded to the battery connecting piece 100, it can be reliably accommodated in the accommodating space 231 formed between the battery connecting piece 100 and the lower plastic part 230, avoiding the battery connecting piece 100 from squeezing the tab 310 when the battery connecting piece 100 and the pole column 220 are welded.

[0044] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A battery connecting sheet, arranged between a cover plate (200) and a core package (300), characterized in that: The battery connecting piece (100) comprises a connecting piece body (110), wherein the connecting body has a protruding portion (120) on one side facing the cover plate (200), wherein the protruding portion (120) is used for welding with a pole (220) on the cover plate (200), and the top surfaces of the connecting body on both sides of the protruding portion (120) respectively have welding areas (130) along the width direction of the cover plate (200), and the core package (300) is provided with a pole ear (310), wherein the pole ear (310) is located between the cover plate (200) and the connecting piece body (110), and the pole ear (310) is welded to the welding area (130).

2. The battery connecting piece according to claim 1, characterized in that: The protruding portion (120) is located at the center of the connecting piece body (110).

3. The battery connecting piece according to claim 2, characterized in that: A groove (140) corresponding to the position of the protruding portion (120) is formed on a side of the connecting piece body (110) away from the cover plate (200).

4. The battery connecting piece according to claim 1, characterized in that: The width of the connecting piece body (110) is greater than or equal to the width of the tab (310).

5. The battery connecting piece according to claim 1, characterized in that: The length of the connecting piece body (110) is smaller than the width of the cover plate (200).

6. The battery connecting piece according to claim 1, characterized in that: The thickness of the protruding portion (120) is greater than or equal to the thickness of the tab (310).

7. The battery connecting piece according to claim 1, characterized in that: The edges of the welding area (130) are provided with rounded corners.

8. A lithium battery, comprising a housing (400), two core packs (300) disposed in the housing (400), and a cover plate (200) connected to an opening of the housing (400), characterized in that: It also comprises the battery connecting piece (100) according to any one of claims 1 to 7, wherein the core package (300) is provided with a pole ear (310), and the pole ear (310) is welded to the cover plate (200) through the battery connecting piece (100).

9. The lithium battery according to claim 8, characterized in that: The cover plate (200) comprises a bare aluminum plate (210), a pole (220) and a lower plastic part (230); two poles (220) are provided, respectively located at two ends of the bare aluminum plate (210) in the length direction; the lower plastic part (230) is fixedly arranged on the bottom surface of the bare aluminum plate (210); the battery connecting piece (100) is located on a side of the lower plastic part (230) away from the bare aluminum plate (210); the protrusion (120) on the battery connecting piece (100) is welded to the pole (220) passing through the lower plastic part (230); and a receiving space (231) for receiving the pole ear (310) is provided between the welding area (130) and the lower plastic part (230).

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