Battery

Abstract

The battery comprises a shell, a top cover assembly and a core bag, the top cover assembly is arranged at one end of the shell, a containing cavity is defined between the top cover assembly and the shell, the core bag is arranged in the containing cavity, the top cover assembly comprises a pole, a groove is formed in the end, facing the containing cavity, of the pole, the groove is provided with an inner wall, and a groove opening of the groove faces the core bag. The core package comprises a tab, and the free end of the tab is fixedly connected with the inner wall. The tabs are directly connected to the poles, and electrical connection between the core package and the poles is realized without using a switching piece, so that the structure is simplified, and the space utilization rate in the battery is improved. As the tabs are directly welded with the poles, only one welding procedure needs to be completed when the battery is assembled. Welding procedures are reduced, and assembling efficiency is improved. And moreover, the resistance of the whole battery can also be reduced due to the omission of an adapter sheet.

Description

Technical Field

[0001] The utility model relates to a battery. Background Art

[0002] A conventional battery comprises a housing, a core pack, and a top cap assembly. The top cap assembly is mounted on the open end of the housing, forming a cavity between the top cap assembly and the housing for mounting the core pack. The top cap assembly includes a terminal for electrical connection to external equipment. The core pack is mounted within the cavity, and the tabs on the core pack are connected to the terminal via an adapter to achieve electrical continuity between the terminal and the core pack. The adapter is a common component in batteries, and its primary function is to ensure stable current transmission.

[0003] However, some studies have found that the adapter takes up a certain amount of space inside the battery, reducing space utilization. Because the adapter needs to be welded to the terminal post and the tab separately, the battery assembly process requires two welding steps. Furthermore, the presence of the adapter increases the resistance of the entire battery. Utility Model Content

[0004] The purpose of the utility model is to provide a battery with high internal space utilization, reduced welding processes during assembly, and low overall resistance.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] A battery is provided, comprising a shell, a top cover assembly and a core pack, wherein the top cover assembly is arranged at one end of the shell, and an accommodating cavity is formed between the top cover assembly and the shell, and the core pack is arranged in the accommodating cavity, the top cover assembly includes a pole, and a groove is provided at one end of the pole facing the accommodating cavity, the groove has an inner wall, and the notch of the groove faces the core pack, and the core pack includes a pole ear, and the free end of the pole ear is connected and fixed to the inner wall.

[0007] Furthermore, the length direction of the groove is parallel to the length direction of the top cover assembly, the length dimension of the groove is L1, the length dimension of the free end of the tab is L2, and L1>L2.

[0008] Furthermore, the inner wall includes a first welding surface and a second welding surface, the first welding surface is located at the bottom of the groove, the second welding surface is surrounded by the first welding surface, and the second welding surface is located between the first welding surface and the notch of the groove, and the free end of the tab is welded and fixed to the first welding surface and / or the second welding surface.

[0009] Furthermore, the second welding surface is parallel to the depth direction of the groove, and the first welding surface is perpendicular to the second welding surface.

[0010] Furthermore, an included angle between the first welding surface and the depth direction of the groove is α, and 55°≤α≤75°.

[0011] Furthermore, the inner wall of the groove is a curved surface structure.

[0012] Furthermore, the groove is filled with an adhesive protective layer, a weld mark area is formed at the connection between the electrode tab and the electrode column, and the protective layer covers the weld mark area.

[0013] Furthermore, the protective layer fills the entire groove.

[0014] Furthermore, the top cover assembly also includes a cover plate, an insulating member and a sealing member. The cover plate is arranged on the open end of the shell, the pole is passed through the cover plate, and the insulating member and the sealing member are clamped between the pole and the cover plate.

[0015] Furthermore, the pole includes a main body and an extension portion, the main body is inserted into the cover plate, the groove is arranged at one end of the main body facing the accommodating cavity, the extension portion is annular, one end of the inner ring of the extension portion is connected to the end of the main body facing the accommodating cavity, and one end of the outer ring of the extension portion extends in a direction away from the main body.

[0016] The beneficial effects of the present invention are as follows: by directly connecting the tabs to the poles, the use of adapters to achieve electrical connection between the core pack and the poles is eliminated, which is conducive to simplifying the structure and improving the space utilization inside the battery. Since the tabs are directly welded to the poles, only one welding process needs to be completed when assembling the battery. Compared with the connection method using adapters in the prior art, one end of the adapter is welded and fixed to the pole, and the other end is welded and fixed to the tabs. Therefore, the connection method of this embodiment is conducive to reducing the welding process and improving assembly efficiency. In addition, since the use of adapters is eliminated, the resistance of the entire battery can also be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a front view of the battery according to the first embodiment of the present invention.

[0018] Figure 2 This is a top view of the battery according to the first embodiment of the present invention.

[0019] Figure 3 This is a cross-sectional view of the top cover assembly of Example 1 of the present utility model.

[0020] Figure 4 This is a schematic diagram of the connection between the pole and the core package in Example 1 of the present utility model.

[0021] Figure 5This is a schematic diagram of the connection between the pole and the core package in the second embodiment of the present invention.

[0022] Figure 6 This is a schematic diagram of the connection between the pole and the core package in the third embodiment of the present invention.

[0023] Figure 7 This is a cross-sectional view of a pole according to a fourth embodiment of the present invention.

[0024] Figure 8 This is a cross-sectional view of a pole according to a fifth embodiment of the present invention.

[0025] Figure 9 This is a cross-sectional view of a pole according to a sixth embodiment of the present invention.

[0026] Figure 10 This is a cross-sectional view of a pole according to a seventh embodiment of the present invention.

[0027] In the picture:

[0028] 1. Shell; 11. Open end; 2. Top cover assembly; 21. Cover plate; 22. Pole; 221. Groove; 2211. First welding surface; 2212. Second welding surface; 2213. Third welding surface; 222. Main body; 223. Extension; 23. Liquid injection hole; 24. Insulator; 25. Seal; 26. Press plate; 3. Core package; 31. Tab; 4. Protective layer. DETAILED DESCRIPTION

[0029] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved more clear, the technical solutions of the present invention are further explained below with reference to the accompanying drawings and through specific implementation methods.

[0030] Example 1

[0031] like Figures 1 to 4As shown, the present invention provides a battery comprising a housing 1, a top cover assembly 2, and a core pack 3. The outer shape of the housing 1 matches the outer shape of the entire battery. In this embodiment, the battery is a prismatic battery, with the length of the battery extending in the X direction, the thickness extending in the Y direction, and the height extending in the Z direction. Accordingly, the housing 1 is a hollow rectangular parallelepiped structure. The housing 1 includes a chamber for accommodating the core pack 3 and the electrolyte. One end of the housing 1 in the height direction forms an opening for connecting the chamber with the exterior of the battery, i.e., one end of the housing 1 in the height direction forms an open end 11. The top cover assembly 2 is disposed over the open end 11 of the housing 1 and is used to seal the open end 11, thereby enclosing the chamber within the battery. A chamber is defined between the top cover assembly 2 and the housing 1. The core pack 3 is mounted within the chamber and stores electrical energy through electrochemical conversion. The core pack 3 includes a stacked or wound current collector assembly and a tab 31 formed on the current collector assembly, which is used for current diversion. The top cover assembly 2 includes a pole 22, which acts as a current guide. One end of the pole 22 is used to electrically connect to the core pack 3, and the other end is used to electrically connect to external power equipment. One end of the pole 22 faces the outside of the battery, and the other end faces the inside of the battery. A groove 221 is provided at the end of the pole 22 that faces the accommodating cavity inside the battery. The groove 221 has an inner wall, and the notch of the groove 221 faces the core pack 3. The end of the tab 31 that faces away from the current collector assembly is a free end, and the free end of the tab 31 is fixedly connected to the inner wall of the groove 221.

[0032] It is understandable that by directly connecting the tab 31 to the pole 22, eliminating the use of an adapter to achieve electrical connection between the core pack 3 and the pole 22, it is beneficial to simplify the structure and improve the space utilization inside the battery. The tab 31 and the pole 22 are connected and fixed by laser welding. Since the tab 31 is directly welded to the pole 22, only one welding process needs to be completed when assembling the battery. Compared with the connection method using an adapter in the prior art, one end of the adapter is welded and fixed to the pole 22, and the other end is welded and fixed to the tab 31. Therefore, the connection method of this embodiment is beneficial to reducing the welding process and improving assembly efficiency. In addition, since the use of the adapter is eliminated, the resistance of the entire battery can also be reduced.

[0033] Specifically, the top cover assembly 2 includes a cover plate 21, a pole 22, an insulating member 24, a sealing member 25 and a pressure plate 26. The cover plate 21 is a rectangular flat plate. The cover plate 21 is covered on the open end 11 of the shell 1 and is welded and fixed to the shell 1. There are two poles 22, which are respectively a positive pole and a negative pole. The positive pole and the negative pole are spaced apart along the length direction of the cover plate 21 (the X direction in the figure). Each pole 22 is correspondingly provided with an insulating member 24, a sealing member 25 and a pressure plate 26. The insulating member 24 is made of an insulating material and plays an insulating role. The sealing member 25 is made of an insulating material with a certain elasticity and plays an insulating and sealing role. The pole 22 is passed through the cover plate 21, and the insulating member 24 and the sealing member 25 are sandwiched between the pole 22 and the cover plate 21. The pole 22 includes a main body 222 and an extension 223. The main body 222 is a rectangular parallelepiped structure, and the main body 222 is passed through the cover plate 21. The groove 221 is provided at one end of the main body 222 facing the accommodating cavity. Correspondingly, the cross-section of the groove 221 is rectangular, so that the groove 221 has sufficient space in the length direction (X direction in the figure) to adapt to the size of the tab 31. Of course, in other embodiments, the shape of the groove 221 can also be adaptively set according to the shape and size of the tab 31. The extension portion 223 is located on the side of the cover plate 21 close to the interior of the battery. The extension portion 223 is annular and is provided at one end of the main body 222 facing the accommodating cavity. One end of the inner ring of the extension portion 223 is connected to the main body 222, and one end of the outer ring of the extension portion 223 extends in a direction away from the main body 222. In this embodiment, the extension portion 223 is integrally formed with the main body 222, and the extension portion 223 is parallel to the cover plate 21. The pressure plate 26 is arranged at the end of the main body 222 facing the outside of the battery. The pressure plate 26 is annular, and the inner ring end of the pressure plate 26 is welded and fixed to the main body 222, and the outer ring end of the pressure plate 26 extends in the direction away from the main body 222. Alternatively, the pressure plates 26 are riveted to each other. Under the action of the pressure plate 26 and the extension 223, the installation and fixation of the pole 22 is achieved. It can also be understood that the cover plate 21 is clamped between the pressure plate 26 and the extension 223. In order to achieve insulation and sealing between the pole 22 and the cover plate 21, the seal 25 is sleeved at the connection between the main body 222 and the extension 223, so that the main body 222 and the cover plate 21, and the extension 223 and the cover plate 21 can be separated by the seal 25. Furthermore, the insulating member 24 is located on a side of the sealing member 25 away from the accommodating cavity, and the main body 222 and the cover plate 21 , as well as the pressing plate 26 and the cover plate 21 are separated by the insulating member 24 .

[0034] Specifically, the length direction of the groove 221 (the X direction shown in the figure) is parallel to the length direction of the top cover assembly 2, so that the length direction of the groove 221 is parallel to the length direction of the tab 31, preventing the tab 31 from twisting during installation. It should be noted that the length direction of the groove 221 is set to be parallel to the length direction of the top cover assembly 3 in order to match the shape of the groove 221 with the spatial position of the tab 31. After the core package 3 is installed in the accommodating cavity, the length direction of the tab 31 is exactly parallel to the length direction of the top cover assembly 2. This ensures that the length direction of the tab 31 (the X direction shown in the figure) is parallel to the length direction of the groove 221. When installing the tab 31, the tab 31 can be simply folded along its thickness direction to abut the sidewall of the groove 221. This method can prevent the tab 31 from twisting along its length direction. Therefore, in other embodiments, the length direction of the groove 221 should match the length direction of the tab 31 to facilitate installation. The length of the groove 221 is L1, and the length of the free end of the tab 31 is L2. If the free end of the tab 31 has an irregular shape, its length L2 is the maximum length. In this embodiment, the length L1 of the groove 221 is greater than the length L2 of the free end of the tab 31 to facilitate installation of the tab 31 and ensure the connection strength between the tab 31 and the terminal 22.

[0035] In some embodiments, the length of the current collector assembly in the core pack 3 is 100mm-1000mm. Taking 100mm, 200mm, 300mm, 400mm, and 500mm as examples, the length L2 of the tab 31 is set to 10-20mm, 20-40mm, 40-60mm, 60-80mm, and 80-100mm, respectively. In this embodiment, by setting the length L2 of the free end of the tab 31 within 10-20% of the length of the current collector assembly, the current carrying capacity of the tab 31 can be effectively increased, ensuring that the current carrying capacity at the tab 31 meets high-current operating conditions, thereby improving the heat dissipation and safety of the battery. In practical applications, the ratio of the length of the tab 31 to the length of the current collector assembly is controlled between 14-15% to achieve optimal current carrying and heat dissipation performance.

[0036] In some embodiments, the length dimension L1 of the groove 221 is greater than the length dimension L2 of the tab 31, and L1-L2=1-10 mm. Preferably, the difference between the length dimension L1 of the groove 221 and the length dimension L2 of the tab 31 is in the range of 2-6 mm. This structure is conducive to ensuring the effective welding area of ​​the tab 31, but it may inevitably cause space waste in the groove 221. In actual applications, taking a certain model of battery A as an example: the length dimension of its current collector assembly is 275.8 mm, the length dimension L2 of the free end of the tab 31 is 39.43 mm, and the length dimension L1 of the groove 221 is selected to be 45 mm. Taking a certain model of battery B as an example: the length dimension of its current collector assembly is 398.7 mm, the length dimension L2 of the free end of the tab 31 is 59 mm, and the length dimension L1 of the groove 221 is selected to be 63 mm.

[0037] Specifically, the cover plate 21 is further provided with a liquid injection hole 23 , through which the electrolyte is injected into the accommodating cavity.

[0038] Specifically, the inner wall of the groove 221 includes a first welding surface 2211 and a second welding surface 2212. The first welding surface 2211 is located at the bottom of the groove 221, that is, the bottom of the groove 221 forms the first welding surface 2211. The second welding surface 2212 is arranged around the circumference of the first welding surface 2211 and is located between the first welding surface 2211 and the notch of the groove 221, that is, the groove wall of the groove 221 forms the second welding surface 2212. The free end of the tab 31 can be welded to the first welding surface 2211 or to the second welding surface 2212. If there are multiple tabs 31, some of the tabs 31 can be welded to the first welding surface 2211, and the other parts of the tabs 31 can be welded to the second welding surface 2212.

[0039] In this embodiment, the tab 31 is welded to the first welding surface 2211. The second welding surface 2212 is parallel to the depth direction of the groove 221 (Z direction in the figure), and the first welding surface 2211 is perpendicular to the second welding surface 2212. The tab 31 is fixed to the first welding surface 2211 by laser welding, and a weld mark area is formed at the connection between the tab 31 and the first welding surface 2211 of the pole 22. The groove 221 is filled with a protective layer 4 with adhesive properties. The protective layer 4 can be a hot melt adhesive polymer, a photocurable polymer or a pressure-sensitive adhesive polymer. Filling the protective layer 4 in the groove 221 is also called glue injection. By glue injection, the protective layer 4 can cover the weld mark area to prevent the welding slag formed during welding from falling onto the core package 3 and causing a short circuit. In addition, by glue injection, the protective layer 4 also plays a role in bonding and fixing the tab 31, further improving the stability of the connection between the tab 31 and the pole 22. In order to improve the fixing effect of the protective layer 4 on the electrode tab 31 , the protective layer 4 fills the entire groove 221 so that the end of the electrode tab 31 facing away from the current collector assembly is embedded in the protective layer 4 .

[0040] Example 2

[0041] like Figure 5 As shown, some reference numbers refer to Figure 3 The present invention provides a battery having a structure similar to that of the first embodiment, except that the angle between the first welding surface 2211 and the depth direction of the groove 221 is α, and 55°≤α≤75°. Specifically, the value of α includes but is not limited to 55°, 60°, 65°, 70°, and 75°. It can be understood that the tab 31 on the core pack 3 extends along the height direction of the battery, that is, the extension direction of the tab 31 is parallel to the depth direction of the groove 221. By controlling the angle between the first welding surface 2211 and the depth direction of the groove 221 to be between 55° and 75°, the first welding surface 2211 can be tilted toward the extension direction of the tab 31. This structure is beneficial for reducing the bending length of the tab 31 when installing the tab 31, thereby preventing some tabs 31 from being damaged due to excessive bending during installation.

[0042] Example 3

[0043] like Figure 6 As shown, some reference numbers refer to Figure 3 The present invention provides a battery having a structure similar to that of the first embodiment, except that the tab 31 is welded to the second welding surface 2212. It is understood that the tab 31 on the core pack 3 extends along the height of the battery, i.e., the extension direction of the tab 31 is parallel to the depth direction of the groove 221. The second welding surface 2212 is parallel to the extension direction of the tab 31. This reduces the bending length of the tab 31 during installation, preventing damage to the tab 31 due to excessive bending during installation.

[0044] Example 4

[0045] like Figure 7 As shown, some reference numbers refer to Figure 3 The utility model provides a battery, whose structure is similar to that of the first embodiment, except that the inner wall of the groove 221 is a curved surface structure. It can be understood that the tab 31 on the core pack 3 extends along the height direction of the battery, that is, the extension direction of the tab 31 is parallel to the depth direction of the groove 221. When installing the tab 31, it is necessary to bend the tab 31 so that the end of the tab 31 fits on the inner wall of the groove 221. By setting the inner wall of the groove 221 as a curved surface structure, the curved surface structure can better adapt to the curved shape of the tab 31, thereby avoiding damage to the tab 31 due to excessive bending during installation.

[0046] Example 5

[0047] like Figure 8 As shown, some reference numbers refer to Figure 3 The utility model provides a battery, whose structure is similar to that of the first embodiment, except that the inner wall of the groove 221 is a "V"-shaped structure. It can be understood that the tab 31 of the core pack 3 extends along the height direction of the battery, that is, the extension direction of the tab 31 is parallel to the depth direction of the groove 221. When installing the tab 31, it is necessary to bend the tab 31 so that the free end of the tab 31 fits on the inner wall of the groove 221. By setting the inner wall of the groove 221 to a "V"-shaped structure, the tab 31 can be divided into two parts and installed on the two side walls of the groove 221 respectively, while also preventing the tab 31 from being bent significantly.

[0048] Example 6

[0049] like Figure 9 As shown, some reference numbers refer to Figure 3 The present invention provides a battery having a structure similar to that of the first embodiment, except that the cross-section of the groove 221 is trapezoidal. The bottom of the groove 221 forms a first welding surface 2211, and the wall of the groove 221 forms a second welding surface 2212. The angle between the second welding surface 2212 and the first welding surface 2211 is β, and β>90°. The free end of the tab 31 can be mounted on the first welding surface 2211, or on the second welding surface 2212, or the tab 31 can be mounted on both the first welding surface 2211 and the second welding surface 2212.

[0050] Example 7

[0051] like Figure 10 As shown, some reference numbers refer to Figure 3 The present invention provides a battery having a structure similar to that of the first embodiment, except that the cross-section of the groove 221 is a polygonal structure. The bottom of the groove 221 forms a first welding surface 2211. The groove wall of the groove 221 forms a second welding surface 2212 and a third welding surface 2213 in sequence from the bottom of the groove to the groove mouth. The angle between the second welding surface 2212 and the first welding surface 2211 is β, and β>90°. The free end of the tab 31 can be mounted on at least one of the first welding surface 2211, the second welding surface 2212 and the third welding surface 2213.

[0052] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, according to the concept of the present invention, there may be changes in the specific implementation methods and application scope. The content of this specification should not be understood as limiting the present invention.

Claims

1. A battery comprising a housing, a top cover assembly, and a core pack, wherein the top cover assembly is disposed at one end of the housing, and a receiving cavity is formed between the top cover assembly and the housing, and the core pack is disposed in the receiving cavity, characterized in that: The top cover assembly includes a pole, a groove is provided at one end of the pole facing the accommodating cavity, the groove has an inner wall, and the notch of the groove faces the core package, the core package includes a pole ear, and the free end of the pole ear is connected and fixed to the inner wall.

2. The battery according to claim 1, characterized in that The length direction of the groove is parallel to the length direction of the top cover assembly. The length dimension of the groove is L1, and the length dimension of the free end of the tab is L2, where L1>L2.

3. The battery according to claim 1, characterized in that The inner wall includes a first welding surface and a second welding surface, the first welding surface is located at the bottom of the groove, the second welding surface is surrounded by the first welding surface, and the second welding surface is located between the first welding surface and the notch of the groove, and the free end of the tab is welded and fixed to the first welding surface and / or the second welding surface.

4. The battery according to claim 3, characterized in that The second welding surface is parallel to the depth direction of the groove, and the first welding surface is perpendicular to the second welding surface.

5. The battery according to claim 3, characterized in that An included angle between the first welding surface and the depth direction of the groove is α, and 55°≤α≤75°.

6. The battery according to claim 1, characterized in that The inner wall of the groove is a curved surface structure.

7. The battery according to any one of claims 1 to 6, characterized in that The groove is filled with an adhesive protective layer, a weld print area is formed at the connection between the electrode tab and the pole, and the protective layer covers the weld print area.

8. The battery according to claim 7, characterized in that The protective layer fills the entire groove.

9. The battery according to any one of claims 1 to 6, characterized in that The top cover assembly further includes a cover plate, an insulating member and a sealing member. The cover plate is arranged on the open end of the shell, the pole is passed through the cover plate, and the insulating member and the sealing member are sandwiched between the pole and the cover plate.

10. The battery according to claim 9, characterized in that The pole includes a main body and an extension part, the main body is inserted into the cover plate, the groove is provided at one end of the main body facing the accommodating cavity, the extension part is annular, one end of the inner ring of the extension part is connected to the end of the main body facing the accommodating cavity, and one end of the outer ring of the extension part extends in a direction away from the main body.

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