Connection structure, cover plate assembly and battery

Abstract

A connection structure (100), a cover plate assembly and a battery. The connection structure (100) comprises a tab connecting portion (1) and a terminal post connecting portion (2) which are arranged at an included angle, wherein the tab connecting portion (1) is configured to be connected to a tab (501) of a core pack (500), the terminal post connecting portion (2) is configured to be connected to a terminal post (300), and the thickness of the tab connecting portion (1) is greater than the thickness of the terminal post connecting portion (2), such that a distance from the tab (501) welded to the tab connecting portion (1) to a side surface of the core pack (500) is greater than the thickness of the terminal post connecting portion (2). The thickness of the terminal post connecting portion (2) being smaller than the thickness of the tab connecting portion (1) can increase a distance between a welding position of the tab connecting portion (1) and the core pack (500), so as to reduce the heat transfer speed; and the reduced thickness of the terminal post connecting portion (2) can reduce the space occupied by the tab connecting portion (1) in a housing, thus increasing the utilization rate of the space of the battery, and also increasing the battery capacity.

Description

Connection structure, cover assembly and battery

[0001] This application claims priority to a patent application filed with the State Intellectual Property Office of China on November 30, 2023, with application number 202323266000.X and application name “Connection structure, cover assembly and battery”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a connection structure, a cover assembly and a battery. Background Art

[0003] The battery primarily consists of a housing with an opening, a cover assembly that seals the opening, and a core pack housed within the housing. The core pack has tabs on its sides, which are angled with the cover assembly. The cover assembly includes a top cover and a pole mounted on the top cover. The pole and tab are connected by an L-shaped connecting piece. The connecting piece includes a vertically arranged tab connector and a pole connector. The pole connector is parallel to the top cover and welded to the pole, while the tab connector is located on one side of the core pack and welded to the tab. Technical issues

[0004] However, the existing connecting pieces are all of uniform thickness. In order to prevent the heat generated during the welding of the tab connection and the tab from being easily transferred to the core package, and to prevent the core package from burning and causing a short circuit in the core package, the tab connection needs to be thickened. However, the pole connection will also be thickened, resulting in lower height dimension utilization and reduced battery capacity. Solution

[0005] The present application provides a connection structure for connecting the core pack and the pole of a battery. The connection structure includes a pole tab connection portion and a pole pole connection portion arranged at an angle. The pole tab connection portion is used to connect the pole tab of the core pack, and the pole pole connection portion is used to connect the pole pole. The thickness of the pole tab connection portion is greater than the thickness of the pole pole connection portion, so that the distance from the pole tab welded to the pole tab connection portion to the side of the core pack is greater than the thickness of the pole pole connection portion. Beneficial effects

[0006] This application increases the thickness of the tab connection by making it thicker than the post connection, thereby increasing the distance between the tab connection welding position and the side of the core package where the tab is located. This can reduce the speed at which heat generated during welding is transferred to the core package, thereby reducing the risk of burning and short-circuiting the core package. At the same time, the thickness of the post connection is reduced, avoiding the increase in the internal space occupied by the post connection due to the thickening of the post connection. Therefore, this design can minimize the transfer of welding heat to the core package while maximizing the utilization of the internal space of the battery case along the height direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG1 is a three-dimensional view of the battery of the present application excluding the shell.

[0008] FIG2 is an exploded view of the battery of the present application excluding the housing.

[0009] FIG3 is a cross-sectional view of the battery of the present application.

[0010] FIG4 is an enlarged view of point A in FIG3 .

[0011] FIG5 is a three-dimensional view of the connection structure of the present application.

[0012] FIG6 is a first side view of the connection structure of the present application.

[0013] FIG7 is an enlarged view of point B in FIG6 .

[0014] FIG8 is a second side view of the connection structure of the present application.

[0015] FIG9 is an enlarged view of point C in FIG8 .

[0016] In the picture:

[0017] 1. Tab connection; 11. First substrate; 12. First plate; 13. Insulation cavity; 2. Post connection; 21. Second substrate; 22. Second plate; 23. Fuse hole; 3. Opening; 4. Convex structure;

[0018] 100, connection structure; 200, cover body; 300, pole; 400, plastic part; 401, receiving groove; 500, core package; 501, pole ear; 5011, first section; 5012, second section; 502, slot; 600, insulating sheet; 700, shell.

[0019] Currently, batteries primarily use L-shaped connectors to connect the terminals and tabs, enabling charging and discharging. These connectors consist of vertically arranged tab and terminal connections. The terminal connection is parallel to the top cover and welded to the terminal, while the tab connection is located on the side of the core pack and welded to the tab. The tabs protruding from the side of the core pack occupy internal battery space, reducing internal space utilization and lowering battery capacity.

[0020] As shown in Figures 1 to 4, the present application provides a battery comprising an open housing 700, a core pack 500 disposed within the housing 700, and a cover plate assembly, which seals the open housing. The core pack 500 is provided with a tab 501. The cover plate assembly is arranged at an angle to the side of the core pack 500 provided with the tab 501. The cover plate assembly includes a cover plate, a terminal 300, and a connecting structure 100. The terminal 300 is disposed on the cover plate, and the connecting structure 100 is respectively connected to the terminal 300 and the tab 501.

[0021] Specifically, the tab 501 includes a first section 5011 and a second section 5012 arranged at an angle, and the end of the first section 5011 away from the second section 5012 is connected to the core package 500. The core package 500, the first section 5011 and the second section 5012 together form a slot 502. The connecting structure 100 includes a tab connection part 1 and a pole connection part 2. The tab connection part 1 is inserted into the slot 502 and welded to the second section 5012, and the tab connection part 1 is insulated from the core package 500 to avoid short-circuit damage to the core package 500. The tab 501 is bent and welded to the tab connecting portion 1, which can reduce the length of the tab 501 protruding from the connecting surface of the core package 500, thereby reducing the space occupied by the tab 501 inside the shell 700. Moreover, after the tab 501 is bent, a slot 502 for the tab connecting portion 1 to be plugged in can be formed, so that the tab connecting portion 1 is arranged between the second section 5012 of the tab 501 and the connecting surface, which can avoid the tab connecting portion 1 protruding from the second section 5012 and occupying the internal space of the shell 700. Therefore, this design can effectively reduce the space occupied by the tab 501 and the connecting tab 501 inside the shell 700, improve the space utilization inside the shell 700, and help to increase the battery capacity.

[0022] In one embodiment, an insulating sheet 600 is provided between the tab connection portion 1 and the core package 500. The insulating sheet 600 can insulate and isolate the tab connection portion 1 from the core package 500 to prevent the tab connection portion 1 from directly contacting the core package 500 and causing a short circuit in the core package 500.

[0023] However, since the battery utilizes welding of the tab 501 and the tab connection portion 1, the heat generated during welding is relatively easily transferred to the core package 500. Therefore, there is a risk of the core package 500 being burned during the welding process, causing a short circuit in the core package 500. To prevent the heat generated during welding of the tab connection portion 1 and the tab 501 from being easily transferred to the core package 500 and thus preventing the core package 500 from being burned and causing a short circuit in the core package 500, the tab connection portion 1 needs to be thickened. However, the existing connecting piece is formed by integrally bending a plate, and the bent connecting pieces are all of uniform thickness. Thickening the tab connection portion 1 will also thicken the pole connection portion 2, resulting in low height utilization of the internal space of the housing 700, thereby reducing the battery capacity.

[0024] As shown in Figures 1 to 5, the present application provides a connection structure 100 for use in the battery of the present application. Connection structure 100 includes a tab connection portion 1 and a post connection portion 2, arranged at an angle. Tab connection portion 1 is used to connect to tab 501 of core pack 500, and post connection portion 2 is used to weld to post 300. The thickness of tab connection portion 1 is greater than that of post connection portion 2, so that the distance between tab 501 welded to tab connection portion 1 and the side of core pack 500 where tab 501 is provided is greater than the thickness of post connection portion 2. The greater the weld thickness, the slower the heat generated by welding is transferred. Therefore, making tab connection portion 1 thicker than post connection portion 2 helps reduce the heat transferred to core pack 500 during welding, thereby reducing the risk of burning and short-circuiting the core pack 500. At the same time, the thickness of post connection portion 2 can be reduced to avoid increasing the internal space occupied by post connection portion 2 within housing 700 due to thickening of post connection portion 2. Therefore, this design can prevent welding heat from being transferred to the core package 500 while maximizing the utilization of the internal space of the battery housing 700 along the height direction.

[0025] As shown in Figures 6 and 7 , the tab connection portion 1 includes a first substrate 11. A first plate 12 is spaced apart from at least one side of the first substrate 11 along the thickness direction of the tab connection portion 1 (i.e., along the X1 direction in the figures). The first substrate 11 and the first plate 12 are formed by bending the plates. A thermal insulation cavity 13 is formed between the first substrate 11 and the first plate 12. The side of the first substrate 11 facing away from the first plate 12, or the side of the first plate 12 facing away from the first substrate 11, is used to connect to the tab 501 of the core package 500. In other words, the tab connection portion 1 is bent to form a folded structure, which thickens the tab connection portion 1 while avoiding thickening the post connection portion 2. Furthermore, the thermal insulation cavity 13 is formed between the first substrate 11 and the first plate 12. This thermal insulation cavity 13 reduces the heat transfer rate generated by welding the tab connection portion 1 to the tab 501 of the core package 500, thereby minimizing the amount of heat transferred to the core package 500. This reduces burns and short-circuit damage to the core package 500, thereby improving battery production yield. At the same time, when the battery is in use, the heat-insulating cavity 13 can allow the electrolyte inside the shell 700 to circulate, so as to improve the electrolyte injection efficiency and the infiltration effect of the core package 500, thereby improving the performance of the battery.

[0026] It should be noted that in this embodiment, the first substrate 11 is inserted into the slot 502 of the core package 500, and the side of the first substrate 11 facing away from the first plate 12 is welded to the second section 5012 of the tab 501. Of course, in other embodiments, without considering the space utilization inside the housing 700, the tab connection portion 1 can also be arranged on the side of the second section 5012 of the tab 501 facing away from the core package 500, and the side of the first plate 12 facing away from the first substrate 11 is welded to the side of the second section 5012 facing away from the core package 500.

[0027] In one embodiment, as shown in Figures 5 to 8 , two first plates 12 are connected to each end of the first substrate 11 along its width (i.e., direction Y1 in the figures). The two first plates 12 are located on the same side of the first substrate 11, and an opening 3 is spaced between the two first plates 12, communicating with the thermal insulation cavity 13. In other words, the ends of the tab connection portion 1 are folded toward the center to form two symmetrical folds. The opening 3 is spaced between the two folds to prevent the two folds from overlapping during bending, which would increase the thickness of the tab connection portion 1. This also prevents the actual thickness of the tab connection portion 1 from being inconsistent with the designed thickness, which would result in the tab connection portion 1 being unable to plug into the slot 502 on the core package 500. Furthermore, when the battery is in use, electrolyte can flow directly between the thermal insulation cavity 13 and the core package 500 through the opening 3, shortening the electrolyte flow path, improving electrolyte injection efficiency, and improving the wetting effect of the core package 500.

[0028] Of course, in other embodiments, one end of the tab connecting portion 1 may also be folded toward the other end along a “Z”-shaped path to form a first folding structure, and the first folding structure forms a folding portion.

[0029] In one embodiment, the thickness of the heat-insulating cavity 13 is T1, the thickness of the tab connection portion 1 is T2, and the thickness of the tab 501 is T3. If the thickness of the insulation cavity 13 is too large, the space inside the shell 700 occupied by the tab connection part 1 will be increased, while if the thickness of the insulation cavity 13 is too small, the insulation effect of the insulation cavity 13 will be reduced. This design can determine the thickness of the insulation cavity 13 and the tab connection part 1 by the total thickness of the tab connection part 1 and the tab 501 after stacking and the thickness of the tab 501, so as to reduce the space inside the shell 700 occupied by the tab connection part 1 as much as possible while ensuring the insulation effect of the insulation cavity 13, thereby improving the utilization rate of the internal space of the shell 700.

[0030] Specifically, the side of the first substrate 11 facing away from the first plate 12 is welded to the tab. The first substrate 11 includes a welding area and a non-welding area. The welding area is used to connect with the tab 501 of the core package 500. The first plate 12 at least partially overlaps with the welding area to block the transfer of welding heat and reduce the transfer speed of welding heat. The opening 3 is opposite to the non-welding area to reduce the heat directly transferred from the opening 3 to the core package 500.

[0031] In one embodiment, the width of the first substrate 11 is L1, the width of the opening 3 is L2, . 0.8mm≥L2≥0.1mm, in this embodiment, L2 is 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, etc. If the width of the opening 3 is too large, the area of ​​the welding area will be reduced, resulting in a small welding area between the tab connection part 1 and the tab 501, which will affect the flow capacity of the tab 501 and the tab connection part 1. If the width of the opening 3 is too small, it will be unfavorable for the circulation of the electrolyte and affect the wetting effect of the core package 500. This design can improve the circulation efficiency of the electrolyte as much as possible under the premise of ensuring the welding area of ​​the tab connection part 1 and the tab 501, so as to balance the wetting effect and flow capacity of the core package 500, thereby ensuring the performance of the battery.

[0032] Specifically, as shown in Figures 4, 5 and 8, the first plate 12 is provided with a convex structure 4 protruding toward one side of the core package 500, and the convex structure 4 is opposite to the non-welding area. When the tab connection part 1 is inserted into the slot 502, the convex structure 4 can be insulated and abutted with the connection surface of the core package 500 through the insulating sheet 600, so as to separate the welding area from the core package 500, and make the side of the first substrate 11 away from the core package 500 fit with the second section 5012 of the tab 501, thereby limiting the lateral shaking of the tab connection part 1 in the slot 502, so as to facilitate the welding of the first substrate 11 and the tab 501, and at the same time separate the first substrate 11 and the core package 500 to avoid damage to the core package 500 during welding; moreover, the convex structure 4 can be used as a reinforcing structure to improve the structural strength of the connection of the tab 501, so that the tab connection part 1 is not easily damaged or deformed.

[0033] In one embodiment, the convex structure 4 is formed by stamping the tab connecting portion 1 .

[0034] It should be noted that, in the aforementioned embodiment, the thickness of the tab connection portion 1 is greater than the thickness of the pole connection portion 2 , wherein the total thickness H2 of the tab connection portion 1 refers to the thickness including the thickness H1 of the convex structure 4 .

[0035] In one embodiment, the thickness of the convex structure 4 is H1, and the total thickness of the tab connection portion is H2. 5mm≥H2≥0.5mm. In this embodiment, H2 is 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, 3.4mm, 3.5mm, 3.8mm, 4mm, 4.4mm, 4.5mm, 4.7mm, 5mm, etc. If the protruding thickness of the convex structure 4 is too large, the space occupied by the tab connection part 1 inside the shell 700 will be increased, thereby reducing the space utilization rate inside the shell 700. If the protruding thickness of the convex structure 4 is too small, the distance between the tab connection part 1 and the core package 500 will be too small, resulting in burn damage to the core package 500 during welding. This design can ensure that there is sufficient thermal insulation distance between the core package 500 and the welding area of ​​the tab connection part 1, while reducing the protruding thickness of the tab connection part 1 as much as possible to improve the space utilization inside the shell 700.

[0036] In one embodiment, the pole connecting portion 2 includes a second substrate 21. Along the thickness direction of the pole connecting portion 2 (i.e., the X2 direction in the figure), a second plate 22 is provided on at least one side of the second substrate 21. The second substrate 21 and the second plate 22 are formed by bending the plate to improve the structural strength of the pole connecting portion 2.

[0037] In one embodiment, the pole connection portion 2 and the tab connection portion 1 are integrally bent from a single plate to improve the overall structural strength of the connection structure 100. The pole connection portion 2 and the tab connection portion 1 are arranged vertically, i.e., the entire plate is bent 90° at a time to form the pole connection portion 2 and the tab connection portion 1.

[0038] Because the pole connection portion 2 and the tab connection portion 1 are integrally bent, the thicknesses of the first substrate 11, the first plate 12, the second substrate 21, and the second plate 22 are substantially the same. In one embodiment, as shown in Figures 8 and 9, multiple first plates 12 are provided on at least one side of the first substrate 11, and multiple second plates 22 are provided on at least one side of the second substrate 21. That is, the pole connection portion 2 is formed by multiple bending of the plate to form a multi-layer folded structure, and the tab connection portion 1 is formed by multiple bending of the plate to form a multi-layer folded structure. The number of first plates 12 is greater than the number of second plates 22, so that the total thickness of the tab connection portion 1 is greater than the total thickness of the pole connection portion 2.

[0039] In one embodiment, the first substrate 11 and the first plate 12 are spaced apart, and the two adjacent first plates 12 are spaced apart, and the second substrate 21 and the second plate 22 and the two adjacent second plates 22 are fitted together, so that the total thickness of the tab connection portion 1 is greater than the total thickness of the pole connection portion 2.

[0040] In another embodiment, the number of the first plates 12 may be greater than the number of the second plates 22 , so that the total thickness of the tab connection portion 1 is greater than the total thickness of the pole connection portion 2 .

[0041] Of course, in other embodiments, the first substrate 11 and the first plate 12 and the two adjacent first plates 12 may be spaced apart, the second substrate 21 and the second plate 22 and the two adjacent second plates 22 may be fitted together, and the number of first plates 12 may be greater than or equal to the number of second plates 22, so as to achieve a total thickness of the tab connection portion 1 that is greater than the total thickness of the pole connection portion 2.

[0042] Specifically, as shown in FIG5 , the terminal connection portion 2 is further provided with a fuse hole 23. This design allows the portion of the connection structure 100 where the fuse hole 23 is provided to have a high resistance. When the battery experiences thermal runaway and the temperature of the connection structure 100 rises significantly, the portion of the connection structure 100 where the fuse hole 23 is provided can fuse first, thereby preventing the battery from experiencing high-temperature runaway and improving battery safety.

[0043] As shown in Figure 2, the present application also provides a cover assembly, including a cover body 200, a pole 300, a plastic part 400 and a connecting structure 100 of any of the above embodiments, the plastic part 400 is arranged on one side of the cover body 200, the plastic part 400 is provided with a through hole, the pole 300 is arranged on the cover body 200, one end of the pole 300 is passed through the through hole, and the other end of the pole 300 is located on the side of the cover body 200 away from the plastic part 400, and the side of the plastic part 400 away from the cover body 200 is also recessed with a receiving groove 401, the through hole passes through the bottom of the receiving groove 401, and the pole connecting part 2 of the connecting structure 100 is arranged in the receiving groove 401 and connected to the pole 300. By providing the accommodating groove 401 , the pole connecting portion 2 can be hidden in the accommodating groove 401 , so that no space for accommodating the pole connecting portion 2 needs to be reserved between the core package 500 and the plastic part 400 , which helps to improve the space utilization inside the battery and thus increase the battery capacity.

Claims

1. A connection structure for connecting a core pack and a pole of a battery, characterized in that: The connection structure includes a pole lug connection portion and a pole column connection portion which are arranged at an angle, the pole lug connection portion is used to connect the pole lug of the core package, and the pole column connection portion is used to connect the pole column, and the thickness of the pole lug connection portion is greater than the thickness of the pole column connection portion, so that the distance from the pole lug welded to the pole lug connection portion to the side of the core package is greater than the thickness of the pole column connection portion.

2. The connection structure according to claim 1, characterized in that: The pole ear connecting portion is protruded toward a side surface of the core package and is provided with a convex structure.

3. The connection structure according to claim 2, characterized in that: The convex structure is formed by stamping the tab connecting portion.

4. The connection structure according to claim 1, characterized in that: The pole lug connecting portion includes a first substrate, and a first plate is spaced apart on at least one side of the first substrate along the thickness direction of the pole lug connecting portion. The first substrate and the first plate are formed by bending plates, and an insulating cavity is formed between the first substrate and the first plate. A side of the first substrate facing away from the first plate or a side of the first plate facing away from the first substrate is used to connect the pole lug of the core package.

5. The connection structure according to claim 4, characterized in that: A side surface of the first substrate facing away from the core package is in contact with the second section of the tab.

6. The connection structure according to claim 4, characterized in that: Two first plates are connected to two ends of the first substrate along the width direction, respectively. The two first plates are located on the same side of the first substrate, and an opening communicating with the heat insulation cavity is spaced between the two first plates.

7. The connection structure according to claim 6, characterized in that: A side of the first substrate facing away from the first plate comprises a welding area and a non-welding area, the welding area is used to connect with the tab, the first plate at least partially overlaps with the welding area, and the opening faces the non-welding area.

8. The connection structure according to claim 4, characterized in that: The side of the first substrate facing away from the first plate includes a welding area and a non-welding area, the welding area is used to connect with the pole ear, and the first plate is provided with a convex structure protruding from one side of the core package, the convex structure is opposite to the non-welding area, and the convex structure is used to be insulated and abutted with the side of the core package to separate the welding area from the core package.

9. The connection structure according to claim 8, characterized in that: The convex hull structure is insulated and abutted against the connecting surface of the core package through an insulating sheet.

10. The connection structure according to claim 6, characterized in that: The width of the first substrate is L1, the width of the opening is L2, ; And / or, the thickness of the heat insulation cavity is T1, the thickness of the pole tab connection portion is T2, and the thickness of the pole tab is T3, ； And / or, the tab connection portion is provided with a convex structure protruding toward a side surface of the core package, the convex structure has a thickness of H1, and the total thickness of the tab connection portion is H2, 。 11. The connection structure according to claim 4, characterized in that: The pole connecting portion includes a second substrate. Along the thickness direction of the pole connecting portion, a second plate is provided on at least one side of the second substrate. The second substrate and the second plate are formed by bending the plate material.

12. The connection structure according to claim 11, characterized in that: The second substrate and the second plate are bonded together; And / or, a plurality of first plates are disposed on at least one side of the first substrate, a plurality of second plates are disposed on at least one side of the second substrate, and the number of the first plates is greater than or equal to the number of the second plates.

13. The connection structure according to any one of claims 1 to 12, characterized in that: The pole connecting portion is also provided with a fuse hole.

14. The connection structure according to any one of claims 1 to 12, characterized in that: The pole connecting portion and the pole lug connecting portion are formed by integrally bending a plate.

15. A cover plate assembly, characterized in that: The connecting structure comprises the connection structure according to any one of claims 1 to 14.

16. The cover plate assembly according to claim 15, characterized in that: It also includes a cover body, a pole and a plastic part, wherein the plastic part is arranged on one side of the cover body, the plastic part is provided with a through hole, the pole is arranged on the cover body, and one end of the pole is passed through the through hole, and a side of the plastic part away from the cover body is also recessed with a receiving groove, the through hole passes through the bottom of the receiving groove, and the pole connecting part of the connecting structure is arranged in the receiving groove and connected to the pole.

17. A battery, comprising a shell with an open opening and a core pack disposed in the shell, wherein the core pack is provided with a tab, characterized in that: It also includes the cover plate assembly according to claim 15 or 16, wherein the cover plate assembly is sealed at the opening, and the pole ear connecting portion of the connecting structure of the cover plate assembly is connected to the pole ear.

18. The battery according to claim 17, characterized in that The pole lug includes a first section and a second section arranged at an angle, the first section is connected to the core package at one end away from the second section, the core package, the first section and the second section together form a slot, the pole lug connecting part is inserted into the slot, the first substrate of the pole lug connecting part is welded to the second section, and the first plate of the pole lug connecting part is insulated from the core package.

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