Secondary battery and electric device

Abstract

The utility model discloses a secondary battery and electric equipment, and belongs to the technical field of batteries, the secondary battery comprises a shell, an electrode assembly and a cover plate assembly, the shell is provided with an accommodating cavity; the electrode assembly is arranged in the accommodating cavity and comprises a body and a tab connected with the body; the cover plate assembly comprises a top cover plate, an electrode terminal and a connecting piece, the top cover plate has a thickness direction, and the top cover plate is connected with the shell in the thickness direction and covers and seals the accommodating cavity; the electrode terminal penetrates through the top cover plate and comprises a first part and a second part, the first part is provided with a first through hole penetrating through the first part in the thickness direction, and the tab penetrates through the first through hole; the second part is connected to one side of the first part away from the body; part of the connecting piece is arranged in the first through hole and connected with the tab, and part of the connecting piece is connected to one side, far away from the body, of the first part. According to the secondary battery, by arranging the connecting pieces which penetrate through the first through holes and are connected with the tabs, the space utilization rate in the secondary battery is improved.

Description

Technical Field

[0001] This application belongs to the field of battery technology, specifically relating to secondary batteries and electrical equipment. Background Technology

[0002] In a secondary battery, the tabs need to be connected to the terminals to draw out the electrical energy of the electrode assembly. The tabs leading out from the electrode assembly body need to be bent to ensure the connection area between the tabs and the electrode terminals, thus ensuring the reliability of the connection and the overcurrent capacity between the tabs and the electrode terminals.

[0003] However, the bent tabs occupy space inside the secondary battery, resulting in low space utilization of the secondary battery. Utility Model Content

[0004] The purpose of this utility model is to provide a secondary battery to solve the technical problem of the difficulty of manual visual inspection of battery leakage; another purpose of this application is to provide an electrical device.

[0005] Technical solution: This application provides a secondary battery, comprising:

[0006] A housing having a receiving cavity;

[0007] An electrode assembly is disposed in the receiving cavity, the electrode assembly including a body and a tab connected to the body;

[0008] A cover plate assembly includes a top cover plate, electrode terminals, and a connecting piece. The top cover plate has a thickness direction and is connected to the housing along the thickness direction, sealing the receiving cavity. The electrode terminals are disposed through the top cover plate and include a first part and a second part. The first part has a first through hole extending through the first part along the thickness direction, and the electrode tab is disposed through the first through hole. The second part is connected to the side of the first part away from the body. A portion of the connecting piece is disposed in the first through hole and fixedly connected to the electrode tab, and a portion of the connecting piece is fixedly connected to the side of the first part away from the body.

[0009] In some embodiments, the top cover plate further has a width direction that intersects the thickness direction;

[0010] The connecting piece includes:

[0011] A first connecting portion is fixedly connected to the side of the first portion away from the body along the thickness direction, and the first connecting portion extends along the width direction;

[0012] The second connecting part is connected to the first connecting part, and a portion of the second connecting part is located in the first through hole. The second connecting part extends along the thickness direction and is fixedly connected to the electrode tab.

[0013] In some embodiments, the first connecting portion and the second connecting portion are integrally formed.

[0014] In some embodiments, along the width direction, the first connecting portion is fixedly connected to one side of the second connecting portion, and the electrode tab is connected to the side of the second connecting portion away from the first connecting portion.

[0015] In some embodiments, the cover plate assembly includes a plurality of connecting pieces, at least two of the connecting pieces having their second connecting portions spaced apart along the width direction to form a first gap, and the tabs being disposed in the first gap and fixedly connected to at least two of the connecting pieces respectively.

[0016] In some embodiments, in two connecting pieces spaced apart along the width direction, two first connecting portions are spaced apart along the width direction and form a second gap, and two second connecting portions are disposed in the second gap.

[0017] In some embodiments, the secondary battery includes a plurality of electrode assemblies, the tabs of the plurality of electrode assemblies are fixedly connected along the width direction and disposed in the first gap; along the width direction, the tabs at both ends of the plurality of tabs are fixedly connected to the connecting pieces located on both sides of the plurality of tabs.

[0018] In some embodiments, the second part has a second through hole extending through the second part along the thickness direction, the second through hole communicating with the first through hole; a portion of the connecting piece is disposed in the second through hole.

[0019] In some embodiments, the cover plate assembly further includes a sealing plate fixedly connected to the second portion on the side away from the first portion along the thickness direction, and covering the second through hole.

[0020] Accordingly, this application also provides an electrical device, including a secondary battery as described in any of the above embodiments.

[0021] Beneficial Effects: Compared with the prior art, the secondary battery provided in this application includes a casing, an electrode assembly, and a cover assembly. The casing has a receiving cavity; the electrode assembly is disposed in the receiving cavity and includes a body and a tab connected to the body; the cover assembly includes a top cover plate, electrode terminals, and a connecting piece. The top cover plate has a thickness direction and is connected to the casing along the thickness direction, sealing the receiving cavity; the electrode terminals are disposed in the top cover plate and include a first part and a second part. The first part has a first through hole extending through the first part along the thickness direction, and the tab is disposed in the first through hole; the second part is connected to the side of the first part away from the body; a portion of the connecting piece is disposed in the first through hole and connected to the tab, and a portion of the connecting piece is connected to the side of the first part away from the body. By providing a connecting piece that passes through the first through hole and is connected to the tab, this application avoids occupying space in the receiving cavity for the tab to bend, while ensuring the connection area between the tab and the electrode terminal, thus improving the space utilization rate inside the secondary battery.

[0022] The electrical equipment in this application includes the aforementioned secondary battery, and therefore can have all the technical features and effects of the aforementioned secondary battery. Attached Figure Description

[0023] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0024] Figure 1 An exploded view of a secondary battery provided in an embodiment of this application;

[0025] Figure 2 This is a schematic diagram of the structure of the cover plate assembly in the secondary battery provided in an embodiment of this application;

[0026] Figure 3 An exploded view of the cover plate assembly in the secondary battery provided in an embodiment of this application;

[0027] Figure 4 A cross-sectional view of a secondary battery provided in an embodiment of this application;

[0028] Figure 5 for Figure 4 Detailed view of point A in the middle circle;

[0029] Figure 6 This is a schematic diagram of the structure of the electrode terminals in a secondary battery provided in an embodiment of this application;

[0030] Figure 7 This is a schematic diagram of the connecting piece in a secondary battery provided in an embodiment of this application.

[0031] Reference numerals in the attached drawings: 100-housing, 110-receiving cavity, 200-electrode assembly, 210-body, 220-electrode tab, 300-cover plate assembly, 310-top cover plate, 320-electrode terminal, 321-first part, 3211-first through hole, 322-second part, 3221-second through hole, 323-third part, 330-connecting piece, 331-first connecting part, 332-second connecting part, 333-first gap, 334-second gap, 340-sealing plate;

[0032] X - width direction, Z - thickness direction. Detailed Implementation

[0033] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0034] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for mutual communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. In the description of this application, "multiple" means two or more, unless otherwise expressly and specifically limited. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features.

[0035] The following disclosure provides many different implementations or examples for carrying out different structures of this application. To simplify the disclosure of this application, the components and arrangements of specific examples are described below. Of course, these are merely examples and are not intended to limit this application.

[0036] In a secondary battery, the tab 220 needs to be connected to the electrode terminal 320 to draw out the electrical energy of the electrode assembly 200. The tab 220, which is drawn out from the body 210 of the electrode assembly 200, needs to be bent to ensure the connection area between the tab 220 and the electrode terminal 320, so as to ensure the reliability of the connection and the overcurrent capacity between the tab 220 and the electrode terminal 320.

[0037] However, the bent tab 220 occupies space inside the secondary battery, resulting in low space utilization of the secondary battery.

[0038] To address the aforementioned technical problem of low space utilization in the secondary battery due to the space occupied by the bent tab 220, the first embodiment of this application provides a secondary battery. Please refer to... Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 The secondary battery includes a housing 100, an electrode assembly 200, and a cover assembly 300. The housing 100 has a receiving cavity 110. The electrode assembly 200 is disposed in the receiving cavity 110 and includes a body 210 and electrode tabs 220 connected to the body 210. The cover assembly 300 includes a top cover plate 310, electrode terminals 320, and connecting pieces 330. The top cover plate 310 has a thickness direction Z and is connected to the housing 100 along the thickness direction Z, sealing the receiving cavity 110. The electrode terminals 320... 20 is disposed on the top cover plate 310. The electrode terminal 320 includes a first part 321 and a second part 322. The first part 321 has a first through hole 3211 that penetrates the first part 321 along the thickness direction Z. The electrode tab 220 is disposed in the first through hole 3211. The second part 322 is connected to the side of the first part 321 away from the body 210. A portion of the connecting piece 330 is disposed in the first through hole 3211 and fixedly connected to the electrode tab 220. A portion of the connecting piece 330 is fixedly connected to the side of the first part 321 away from the body 210.

[0039] Wherein, the thickness direction Z is the direction of the Z arrow in the attached figure.

[0040] In some embodiments, the connecting piece 330 is welded to the tab 220, and the connecting piece 330 is fixedly connected to the first part 321.

[0041] In the above embodiment, the tab 220 is not bent and connected to the electrode terminal 320 in the receiving cavity 110, but extends directly into the first through hole 3211 of the electrode terminal 320 and connects to the electrode terminal 320, which improves the space utilization inside the secondary battery. The unbent tab 220 also reduces the possibility of the tab 220 tearing, thus improving the reliability of the secondary battery.

[0042] Furthermore, the connecting piece 330 is connected to the side of the first part 321 away from the main body 210, replacing the part that needs to be bent and used to connect with the electrode terminal 320. This ensures the connection area between the tab 220 and the electrode terminal 320, thereby reducing the welding difficulty between the tab 220 and the electrode terminal 320 and improving the current flow capacity at the connection between the tab 220 and the electrode terminal 320.

[0043] In addition, the tab 220 in the above embodiment is also connected to the connecting piece 330. After the connecting piece 330 passes through the first through hole 3211, the tab 220 can also follow the connecting piece 330 through the first through hole 3211. The connecting piece 330 plays the role of guiding the tab 220 through the first through hole 3211, reducing the difficulty of passing the relatively soft tab 220 through the first through hole 3211 and reducing the assembly efficiency of the secondary battery.

[0044] In some embodiments, please refer again Figure 4 , Figure 5 and Figure 7 The top cover plate 310 also has a width direction X, which intersects with the thickness direction Z; the connecting piece 330 includes a first connecting part 331 and a second connecting part 332. The first connecting part 331 is fixedly connected to the side of the first part 321 away from the body 210 along the thickness direction Z, and the first connecting part 331 extends along the width direction X; a portion of the second connecting part 332 is connected to the first connecting part 331, a portion of the second connecting part 332 is located in the first through hole 3211, the second connecting part 332 extends along the thickness direction Z, and is fixedly connected to the tab 220.

[0045] Wherein, the width direction X is the direction of the X arrow in the attached figure.

[0046] In some embodiments, the width direction X can actually be a length direction that intersects the thickness direction Z.

[0047] Specifically, during the assembly of the secondary battery, both the first connecting part 331 and the second connecting part 332 extend along the thickness direction Z. First, the second connecting part 332 is welded to the tab 220 along the width direction X, and the connecting piece 330 is passed through the first through hole 3211. After the tab 220 is inserted into the second through hole 3221, the connecting piece 330 is bent so that the first connecting part 331 extends along the width direction X and fits against the side of the first part 321 away from the body 210, and the first connecting part 331 is welded to the first part 321.

[0048] In the above embodiment, the second connecting portion 332, which has a larger size along the thickness direction Z, is used to weld and connect with the tab 220, so as to prevent the tab 220 and the connecting piece 330 from falling off during the process of passing through the first through hole 3211; the first connecting portion 331, which is connected to the side of the first portion 321 away from the body 210 and has a larger size in the width direction X, makes the connecting piece 330 have sufficient area to weld and connect with the electrode terminal 320.

[0049] In addition, the first connecting part 331 also increases the connection area between the tab 220 and the electrode terminal 320, thereby improving the current flow capacity at the connection between the tab 220 and the electrode terminal 320.

[0050] In some embodiments, please refer again Figure 5 The first connecting part 331 and the second connecting part 332 are integrally formed.

[0051] In the above embodiments, the integrally formed first connecting portion 331 and second connecting portion 332 are more tightly connected, resulting in better flow capacity. Furthermore, the integrally formed connecting piece 330 has better mechanical properties; when the connecting piece 330 is bent after passing through the first through hole 3211, the first connecting portion 331 and second connecting portion 332 are less prone to breakage, thus improving the reliability of the connecting piece 330.

[0052] In some embodiments, the first connecting portion 331 and the second connecting portion 332 can also be connected during the assembly of the secondary battery. Specifically, during the assembly of the secondary battery, the second connecting portion 332 is first welded to the tab 220, the second connecting portion 332 is passed through the first through hole 3211 and the tab 220 is also passed through the first through hole 3211, and then the second connecting portion 332 is welded to the first connecting portion 331. At this time, the first connecting portion 331 may have been welded to the electrode terminal 320 or may not have been welded to the electrode terminal 320.

[0053] In some embodiments, please refer again Figure 5 Along the width direction X, the first connecting part 331 is fixedly connected to one side of the second connecting part 332, and the tab 220 is connected to the side of the second connecting part 332 away from the first connecting part 331.

[0054] Specifically, the first through hole 3211 has a hole wall, and the tab 220 is connected to the side of the second connecting part 332 away from the hole wall.

[0055] It is understandable that when the connecting piece 330 and the tab 220 are passed through the first through hole 3211, the tab 220 and the electrode terminal 320 need to move relative to each other along the thickness direction Z so that the tab 220 can be inserted into the first through hole 3211.

[0056] In the above embodiment, positioning the tab 220 on the side of the second connecting portion 332 away from the hole wall allows the second connecting portion 332 of the connecting piece 330 to block the hole wall and the tab 220 when the tab 220 moves relative to the electrode terminal 320. This prevents friction between the tab 220 and the hole wall of the first through hole 3211 when the tab 220 moves relative to the hole wall, thus avoiding wear on the tab 220 and improving the reliability of the secondary battery. Furthermore, since the second connecting portion 332 of the connecting piece 330 can protect the tab 220, the difficulty of inserting the tab 220 into the first through hole 3211 is reduced, lowering the assembly difficulty of the secondary battery and improving its assembly efficiency.

[0057] In some embodiments, please refer again Figure 5 The cover plate assembly 300 includes a plurality of connecting pieces 330. The second connecting portions 332 of at least two connecting pieces 330 are spaced apart along the width direction X to form a first gap 333. The tabs 220 are disposed in the first gap 333 and are fixedly connected to at least two connecting pieces 330 respectively.

[0058] Specifically, along the width direction X, the tab 220 is disposed between the second connecting portions 332 of two adjacent connecting pieces 330. In other words, along the width direction X, the tab 220 is connected to the second connecting portions 332 of the connecting pieces 330 on both sides along the width direction X. That is, in the width direction X, the tab 220 and the hole wall of the first through hole 3211, which are disposed opposite to each other along the width direction X, are blocked by the second connecting portions 332 of the connecting pieces 330.

[0059] In the above embodiment, by providing at least two connecting pieces 330 along the width direction X to prevent the tab 220 from rubbing against the wall of the first through hole 3211 when passing through it, the protective effect of the connecting pieces 330 on the tab 220 is further improved, reducing the assembly difficulty of the secondary battery and improving the assembly efficiency. Furthermore, more connecting pieces 330 can also increase the connection area between the tab 220 and the electrode terminal 320, thereby improving the current-carrying capacity between the tab 220 and the electrode terminal 320.

[0060] In some embodiments, please refer again Figure 5 In the two connecting pieces 330 that are spaced apart along the width direction X, two first connecting parts 331 are spaced apart along the width direction X and form a second gap 334, and two second connecting parts 332 are disposed in the second gap 334.

[0061] Specifically, the first connecting portion 331 of the connecting piece 330, which is spaced apart along the width direction X, is connected to both sides of the electrode terminal 320 located in the first through hole 3211.

[0062] In the above embodiment, along the width direction X, the first connecting portion 331 of the two connecting pieces 330 is connected to both sides of the electrode terminal 320 located in the first through hole 3211. This allows the first connecting portion 331 of the two connecting pieces 330 to have a larger connection area with the electrode terminal 320 while having a small size along the width direction X. This improves the connection stability between the connecting piece 330 and the electrode terminal 320, thereby also improving the reliability of the secondary battery.

[0063] In some embodiments, please refer again Figure 5The secondary battery includes multiple electrode assemblies 200, and the tabs 220 of the multiple electrode assemblies 200 are fixedly connected along the width direction X and disposed in the first gap 333; along the width direction X, among the multiple tabs 220, the tabs 220 located at both ends are fixedly connected to the connecting pieces 330 located on both sides of the multiple tabs 220 respectively.

[0064] It is understandable that as the number of tabs 220 increases, the total size of the multiple tabs 220 along the width direction X also increases, and the possibility of friction when the multiple tabs 220 move relative to the wall of the first through hole 3211 also increases.

[0065] In the above embodiment, by connecting multiple tabs 220 to the first gap 333 at the same time, a connecting piece 330 is provided between the tabs 220 that may rub against the wall of the first through hole 3211 along the width direction X and the wall of the first through hole 3211 to protect the tabs 220. This reduces the possibility of the tabs 220 rubbing against the wall of the first through hole 3211 and causing wear of the tabs 220, and improves the reliability of the secondary battery.

[0066] In some embodiments, please refer again Figure 5 The second part 322 has a second through hole 3221 that extends through the second part 322 along the thickness direction Z, and the second through hole 3221 communicates with the first through hole 3211; a portion of the connecting piece 330 is disposed in the second through hole 3221.

[0067] Specifically, the wall of the second through hole 3221 and the surface of the first part 321 away from the electrode assembly 200 along the thickness direction Z form a receiving cavity 110, and the first connecting part 331 connected to the surface of the first part 321 away from the electrode assembly 200 along the thickness direction Z is located in the receiving cavity 110.

[0068] In the above embodiment, the second part 322 can protect the first connecting part 331 located in the receiving cavity 110, reducing the possibility that the first connecting part 331 may be hit by other objects during the subsequent assembly process of the secondary battery or the battery pack assembly process, causing the connection between the connecting piece 330 and the electrode terminal 320 to fail and the connecting piece 330 to fall off, thereby improving the reliability of the secondary battery and reducing the assembly difficulty of the secondary battery.

[0069] In some embodiments, please refer again Figure 5 And see Figure 6 The cover plate assembly 300 also includes a sealing plate 340, which is fixedly connected to the side of the second part 322 away from the first part 321 along the thickness direction Z, and covers the second through hole 3221.

[0070] Furthermore, the first connecting portion 331 is located between the first portion 321 and the sealing plate 340 along the thickness direction Z.

[0071] Specifically, the sealing plate 340 covers the receiving cavity 110, that is, the sealing plate 340 isolates the inside of the receiving cavity 110 and the receiving cavity 110 formed by the second through hole 3221 from the outside.

[0072] In the above embodiments, the sealing plate 340 can seal the receiving cavity 110, preventing external impurities from entering the receiving cavity 110 and preventing electrolyte leakage, thereby improving the reliability of the secondary battery.

[0073] In some embodiments, please refer again Figure 5 And see Figure 6 The electrode terminal 320 also includes a third part 323, which is connected to the second part 322 on the side away from the first part 321 along the thickness direction Z. The third part 323 is disposed around the sealing plate 340 to limit the sealing plate 340 in a direction perpendicular to the thickness direction Z.

[0074] In some embodiments, the sealing plate 340 is welded to the electrode terminal 320.

[0075] In the above embodiment, before the sealing plate 340 is welded to the electrode terminal 320, the third part 323 disposed around the sealing plate 340 can position the sealing plate 340, reduce the positioning difficulty of the sealing plate 340, and also prevent the sealing plate 340 from shifting during welding, thereby reducing the welding difficulty between the sealing plate 340 and the electrode terminal 320.

[0076] Accordingly, this application also provides an electrical device including a secondary battery as described in any of the above embodiments.

[0077] The electrical equipment in this application includes the aforementioned secondary battery, and therefore can have all the technical features and effects of the aforementioned secondary battery.

[0078] The electrical equipment can be vehicles, energy storage devices, or other application devices. Vehicles can be new energy vehicles, including pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles. This application does not impose any special limitations on the aforementioned electrical equipment.

[0079] The foregoing has provided a detailed description of a secondary battery and electrical device provided in the embodiments of this application. Specific examples have been used in this application to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A secondary battery, characterized in that, include: A housing having a receiving cavity; An electrode assembly is disposed in the receiving cavity, the electrode assembly including a body and a tab connected to the body; A cover plate assembly includes a top cover plate, electrode terminals, and a connecting piece. The top cover plate has a thickness direction and is connected to the housing along the thickness direction, sealing the receiving cavity. The electrode terminals are disposed through the top cover plate and include a first part and a second part. The first part has a first through hole extending through the first part along the thickness direction, and the electrode tab is disposed through the first through hole. The second part is connected to the side of the first part away from the body. A portion of the connecting piece is disposed in the first through hole and fixedly connected to the electrode tab, and a portion of the connecting piece is fixedly connected to the side of the first part away from the body.

2. The secondary battery according to claim 1, characterized in that, The top cover plate also has a width direction, which intersects with the thickness direction; The connecting piece includes: A first connecting portion is fixedly connected to the side of the first portion away from the body along the thickness direction, and the first connecting portion extends along the width direction; The second connecting part is connected to the first connecting part, and a portion of the second connecting part is located in the first through hole. The second connecting part extends along the thickness direction and is fixedly connected to the electrode tab.

3. The secondary battery according to claim 2, characterized in that, The first connecting part and the second connecting part are integrally formed.

4. The secondary battery according to claim 2, characterized in that, Along the width direction, the first connecting portion is connected to one side of the second connecting portion, and the electrode tab is fixedly connected to the side of the second connecting portion away from the first connecting portion.

5. The secondary battery according to claim 2, characterized in that, The cover plate assembly includes a plurality of connecting pieces, and the second connecting portions of at least two of the connecting pieces are spaced apart along the width direction to form a first gap. The electrode tabs are disposed in the first gap and are fixedly connected to at least two of the connecting pieces respectively.

6. The secondary battery according to claim 5, characterized in that, In the two connecting pieces spaced apart along the width direction, the two first connecting portions are spaced apart along the width direction and form a second gap, and the two second connecting portions are disposed in the second gap.

7. The secondary battery according to claim 5, characterized in that, The secondary battery includes multiple electrode assemblies, and the tabs of the multiple electrode assemblies are fixedly connected along the width direction and disposed in the first gap; along the width direction, the tabs at both ends of the multiple tabs are fixedly connected to the connecting pieces located on both sides of the multiple tabs.

8. The secondary battery according to claim 1, characterized in that, The second part has a second through hole extending through the second part along the thickness direction, and the second through hole communicates with the first through hole; a portion of the connecting piece is disposed in the second through hole.

9. The secondary battery according to claim 8, characterized in that, The cover plate assembly further includes a sealing plate, which is fixedly connected to the second part on the side away from the first part along the thickness direction and covers the second through hole.

10. An electrical appliance, characterized in that, Includes the secondary battery as described in any one of claims 1-9.

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