A battery

Abstract

The present invention discloses a battery, which includes a housing, a wound core disposed in the inner cavity of the housing, and a cap assembly for sealing the opening of the housing. The wound core includes a positive electrode plate, a negative electrode plate, and a separator disposed between the positive electrode plate and the negative electrode plate. A positive electrode tab is provided on the positive electrode plate, and the positive electrode tab is connected to the cap assembly. At least two negative electrode tabs are spaced apart on the negative electrode plate, and each negative electrode tab is respectively connected to the housing. By respectively connecting at least two negative electrode tabs to the housing, the connection positions between the negative electrode tabs and the housing can be increased, and the wound core is fixed by connecting the wound core to the housing at multiple locations. During actual transportation, the movement of the wound core in the inner cavity of the housing can be reduced, the possibility of the housing hitting the wound core due to vibration can be decreased, and the anti-vibration ability of the battery can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery manufacturing, and particularly relates to a battery. Background Art

[0002] Batteries have many advantages such as good high-power charge and discharge performance, good temperature characteristics, long cycle service life, and environmental friendliness, and are widely used in various electrical equipment. In particular, lithium-ion batteries not only have a large capacity, but also have the advantages of high power density and high energy density of rechargeable batteries, and have a wide operating temperature range and a long cycle life, and are widely used in mobile devices. The wound core in a lithium battery usually consists of a positive electrode sheet, a negative electrode sheet, and a separator. During the use and transportation of the battery, the wound core is likely to move in the battery case or be easily impacted by external forces, resulting in deformation of the electrode group, which may cause the battery to fail and even lead to safety accidents. The existing batteries have poor anti-vibration performance and it is difficult to ensure the safety and reliability of the batteries during use. Summary of the Invention

[0003] The purpose of the present invention is to provide a battery with good anti-vibration performance and high safety.

[0004] To achieve this purpose, the present invention adopts the following technical solutions:

[0005] Provide a battery, including a case, a wound core disposed in the inner cavity of the case, and a cap assembly for sealing the opening of the case. The wound core includes a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive electrode sheet and the negative electrode sheet. A positive electrode tab is provided on the positive electrode sheet, and the positive electrode tab is connected to the cap assembly. At least two negative electrode tabs are spaced apart on the negative electrode sheet, and each of the negative electrode tabs is connected to the case respectively.

[0006] As a preferred technical solution of the battery, two negative electrode tabs are provided on the negative electrode sheet, and the two negative electrode tabs are a first negative electrode tab and a second negative electrode tab respectively. The first negative electrode tab and the second negative electrode tab extend out from the top and bottom of the wound core respectively. The first negative electrode tab is connected to the upper side wall of the case, and the second negative electrode tab is connected to the bottom of the case.

[0007] As a preferred technical solution of the battery, the first negative electrode tab has a first negative electrode tab segment connected to the wound core and a second negative electrode tab segment disposed away from the wound core. The second negative electrode tab segment is folded towards the outside of the case and then connected to the outer wall of the case, and the first negative electrode tab segment is connected to the inner wall of the case.

[0008] As a preferred technical solution of the battery, an insulating pad is disposed between the bottom of the wound core and the case, and the second negative electrode tab passes through the insulating pad and is connected to the bottom of the case.

[0009] As a preferred technical solution of the battery, a through hole is formed through the insulating pad, and the second negative electrode tab passes through the through hole and is connected to the bottom of the housing.

[0010] As a preferred technical solution of the battery, the negative electrode tab is melt-connected to the housing.

[0011] As a preferred technical solution of the battery, the positive electrode plate is connected to the cap assembly after being bent multiple times;

[0012] And / or, the negative electrode tab is connected to the housing after being bent multiple times.

[0013] As a preferred technical solution of the battery, the outer diameter of the core is adapted to the inner diameter of the housing, the size of the separator is larger than the size of the positive electrode plate and the size of the negative electrode tab respectively. At the upper end of the core, the separator protrudes axially along the core beyond the positive electrode tab and the negative electrode tab, and the top of the separator is attached to the side of the cap assembly close to the core.

[0014] As a preferred technical solution of the battery, the cap assembly includes an end cap, a sealing ring and an isolation ring. The end cap passes through the sealing ring and is connected to the positive electrode tab, and the end cap seals the opening of the sealing ring through the sealing ring. The positive electrode tab is connected to the end cap, the isolation ring is arranged between the top of the core and the sealing ring, and the top of the core is attached to the side of the isolation ring facing away from the sealing ring.

[0015] As a preferred technical solution of the battery, a connecting portion protrudes from the periphery of the sealing ring toward the side away from the core, and the sealing ring is connected to the upper end of the housing in an interference fit through the connecting portion.

[0016] The beneficial effects of the present invention are as follows: By connecting at least two negative electrode tabs to the housing respectively, the connection positions between the negative electrode tabs and the housing can be increased. By fixing the core in a manner of connecting the core to the housing at multiple places, during actual transportation, the movement of the core in the inner cavity of the housing can be reduced, and the possibility of the housing hitting the core due to vibration can be reduced, thereby improving the anti-vibration ability of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described in detail below with reference to the drawings and embodiments.

[0018] Figure 1 It is a partial exploded view of the battery described in the embodiment.

[0019] Figure 2 It is a cross-sectional view of the battery described in the embodiment.

[0020] Figure 3 It is a schematic diagram of a partial structure of the battery described in the embodiment.

[0021] In the figure:

[0022] 1. Outer shell; 2. Winding core; 201. Separator; 202. Positive electrode sheet; 203. Negative electrode sheet; 3. Insulating pad; 4. Groove; 5. Cap assembly; 501. Liquid injection hole; 502. Isolation ring; 503. Sealing ring; 504. Connection part; 505. Sealing nail; 6. Positive electrode tab; 7. First negative electrode tab; 701. First negative electrode tab section; 702. Second negative electrode tab section; 8. Second negative electrode tab; 9. Through hole. Specific embodiments

[0023] To make the technical problems solved by the present invention, the technical solutions adopted and the achieved technical effects clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0024] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected" and "fixed" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0025] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "above" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "below" and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or only means that the horizontal height of the first feature is lower than that of the second feature.

[0026] Such as Figures 1 to 3As shown in the figure, the present invention provides a battery, which includes a housing 1, a winding core 2 disposed in the inner cavity of the housing 1, and a cap assembly 5 for sealing the opening of the housing 1. The winding core 2 includes a positive electrode sheet 202, a negative electrode sheet 203, and a separator 201 disposed between the positive electrode sheet 202 and the negative electrode sheet 203. A positive electrode tab 6 is provided on the positive electrode sheet 202, and the positive electrode tab 6 is connected to the cap assembly 5. At least two negative electrode tabs are spaced apart on the negative electrode sheet 203, and each of the negative electrode tabs is connected to the housing 1 respectively.

[0027] Preferably, each of the negative electrode tabs is spaced apart and connected to the housing 1 at intervals, so as to avoid the coincidence of the negative electrode tabs and reduce the connection area between the negative electrode tabs and the housing 1.

[0028] In this embodiment, by connecting at least two negative electrode tabs to the housing 1 respectively, the connection positions between the negative electrode tabs and the housing 1 can be increased, and the winding core 2 can be fixed by connecting the winding core 2 to the housing 1 at multiple positions. During actual transportation, the movement of the winding core 2 in the inner cavity of the housing 1 can be reduced, and the possibility of the housing 1 hitting the winding core 2 due to vibration can be lowered, thereby improving the anti-vibration ability of the battery. In the batteries in the prior art, usually only one negative electrode tab of the winding core 2 is connected to the housing 1 of the battery. For the batteries with such a structure, during use, the winding core 2 is very likely to be displaced inside the housing 1 due to the vibration of the battery, resulting in the negative electrode tab falling off from the housing 1, causing a short circuit inside the battery, and it is not thought to fix the connection position between the negative electrode tab on the winding core 2 and the housing 1 on the housing.

[0029] In one embodiment, two negative electrode tabs are provided on the negative electrode sheet 203, and the two negative electrode tabs are a first negative electrode tab 7 and a second negative electrode tab 8 respectively. The first negative electrode tab 7 and the second negative electrode tab 8 extend from the top and bottom of the winding core 2 respectively. The first negative electrode tab 7 is connected to the upper side wall of the housing 1, and the second negative electrode tab 8 is connected to the bottom of the housing 1. By connecting the negative electrode tabs of the battery to the upper side wall and the bottom of the housing 1, the upper and bottom parts of the winding core 2 are respectively connected to the housing 1. The top and bottom parts of the winding core 2 are fixed to the housing 1 by a double connection method, so as to avoid the phenomenon that the winding core 2 is displaced inside the housing 1 due to vibration during the use or transportation of the battery, and reduce the friction between the winding core 2 and the inner shell.

[0030] However, in other embodiments, the number of negative electrode tabs provided on the negative electrode sheet 203 can also be three, four, five, etc.

[0031] Specifically, the first negative electrode tab 7 has a first negative electrode tab section 701 connected to the wound core and a second negative electrode tab section 702 disposed away from the wound core 2. The second negative electrode tab section 702 is folded towards the outside of the housing 1 and connected to the outer wall of the housing 1, and the first electrode tab section is connected to the inner wall of the housing 1. In this way, the first electrode tab is connected to both the inner wall and the outer wall of the housing 1, increasing the connection positions of the negative electrode tab and the housing 1 as much as possible and improving the reliability of the battery.

[0032] To further improve the safety performance of the battery, an insulating pad 3 is provided between the bottom of the wound core 2 and the housing 1, and the second negative electrode tab 8 passes through the insulating pad 3 and is connected to the bottom of the housing 1. The insulating pad 3 is provided to space the bottom of the wound core 2 from the bottom of the housing 1, so as to space the second negative electrode tab 8 from the bottom of the wound core 2, and during use, to prevent the second negative electrode tab 8 from contacting the positive electrode tab 6 and causing a short circuit of the wound core 2.

[0033] The insulating pad 3 is connected to the bottom of the wound core 2, and a groove 4 is recessed in the bottom of the housing 1. The second negative electrode tab 8 is connected to the bottom of the groove 4. Through this design, a certain gap can be reserved between the second negative electrode tab 8 and the insulating pad 3. In the case where the insulating pad 3 is damaged, since the second negative electrode tab 8 is connected to the bottom of the groove 4, it is possible to prevent the second negative electrode tab 8 from contacting the positive electrode sheet 202 and causing a short circuit of the wound core 2.

[0034] Preferably, to further increase the contact area between the negative electrode sheet 203 and the housing 1, the second negative electrode tab 8 extends from the bottom of the housing 1 to the side wall of the housing 1, strengthening the reliability of the connection between the negative electrode tab and the housing 1.

[0035] The insulating pad 3 is provided with a through hole 9 therethrough, and the second negative electrode tab 8 passes through the through hole 9 and is connected to the bottom of the housing 1.

[0036] Preferably, the insulating pad 3 is an insulating film.

[0037] The negative electrode tab is melt-connected to the housing 1. By melt-connecting the negative electrode tab to the housing 1, it is not necessary to connect the negative electrode tab to the housing 1 through an adhesive, which can avoid the adhesive absorbing the electrolyte and prevent the connection between the negative electrode tab and the housing 1 from failing due to long-term use or high temperature. The melt connection can improve the service life of the battery and ensure that the wound core 2 is firmly fixed inside the housing 1.

[0038] Preferably, the positive electrode sheet 202 is connected to the cap assembly 5 after being bent multiple times. The negative electrode tab is connected to the outer shell 1 after being bent multiple times. By arranging the positive electrode tab 6 and the negative electrode tab to be bent multiple times, through the elastic damping mechanism of multiple bends, the bent parts on the positive electrode tab 6 and the negative electrode tab are avoided from being stressed, thereby reducing the possibility of the positive electrode tab 6 and the negative electrode tab being broken due to stress.

[0039] In this embodiment, the outer diameter of the core 2 is adapted to the inner diameter of the outer shell 1. The size of the separator 201 is larger than the size of the positive electrode sheet 202 and the size of the negative electrode tab respectively. At the upper end of the core 2, the separator 201 protrudes axially along the core 2 beyond the positive electrode tab 6 and the negative electrode tab, and the top of the separator 201 is attached to the side of the cap assembly 5 close to the core 2. Through this design, the size of the separator 201 is made larger than the size of the positive electrode sheet 202 and the negative electrode sheet 203. By virtue of the size of the separator 201, the top of the separator 201 is attached to the side of the cap assembly 5 close to the core 2, so that the core 2 fills the inner cavity. The separator 201 is used to buffer the pressure of the cap assembly 5, preventing the core 2 from sliding relatively inside the outer shell 1. And because the separator 201 has a certain softness, the separator 201 can be used to buffer the core 2, enhancing the anti-vibration function of the battery, without the need to additionally add other buffer substances outside the core 2, saving the processing procedures of the battery. Specifically, the outer diameter of the core 2 is equal to the inner diameter of the outer shell 1, so that the outer wall of the core 2 is completely attached to the inner wall of the outer shell 1, ensuring that the inner cavity of the outer shell 1 is completely filled.

[0040] In this embodiment, the porosity of the separator 201 is less than 36%.

[0041] The cap assembly 5 includes an end cap, a sealing ring 503 and an isolation ring 502. The end cap passes through the sealing ring 503 and is connected to the positive electrode tab 6, and the end cap seals the opening of the sealing ring 503 through the sealing ring 503. The positive electrode tab 6 is connected to the end cap. The isolation ring 502 is arranged between the top of the core 2 and the sealing ring 503, and the top of the core 2 is attached to the side of the isolation ring 502 facing away from the sealing ring 503. Among them, the end cap and the isolation ring 502 are respectively provided with a liquid injection hole 501 penetrating therethrough, and the liquid injection hole 501 is sealed by the sealing nail 505. During the production of the battery, electrolyte is added through the liquid injection hole 501.

[0042] A connecting portion 504 is protruded from the circumference of the sealing ring 503 toward a side away from the winding core 2, and the sealing ring 503 is connected to the upper end of the housing 1 by interference fit through the connecting portion 504. The provision of the connecting portion 504 can increase the contact area between the sealing ring 503 and the housing 1, thereby improving the reliability of the cap assembly 5 in sealing the opening of the housing 1.

[0043] In the description herein, it should be understood that the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0044] In the description of this specification, the description with reference to the terms "an embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0045] In addition, it should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the purpose of clarifying the device. Those skilled in the art should take the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0046] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. A battery, characterized in that , it includes a housing, a wound core disposed in the inner cavity of the housing, and a cap assembly for sealing the opening of the housing. The wound core includes a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive electrode sheet and the negative electrode sheet. A positive electrode tab is provided on the positive electrode sheet, the positive electrode tab is connected to the cap assembly, at least two negative electrode tabs are spaced apart on the negative electrode sheet, and each of the negative electrode tabs is respectively connected to the housing; The negative electrode sheet includes a first negative electrode tab and a second negative electrode tab. The first negative electrode tab and the second negative electrode tab respectively extend from the top and bottom of the wound core. The first negative electrode tab is connected to the upper side wall of the housing, and the second negative electrode tab is connected to the bottom of the housing; The first negative electrode tab has a first tab segment connected to the wound core and a second negative electrode tab segment disposed away from the wound core. The second negative electrode tab segment is folded towards the outside of the housing and then connected to the outer wall of the housing, and the first tab segment is connected to the inner wall of the housing; The positive electrode sheet is connected to the cap assembly after multiple bends; and / or, the negative electrode tab is connected to the housing after multiple bends.

2. The battery according to claim 1, characterized in that, an insulating pad is provided between the bottom of the wound core and the housing, and the second negative electrode tab passes through the insulating pad and is connected to the bottom of the housing.

3. The battery according to claim 2, characterized in that, the insulating pad is provided with a through hole, and the second negative electrode tab passes through the through hole and is connected to the bottom of the housing.

4. The battery according to claim 1, characterized in that, the negative electrode tab is melt-connected to the housing.

5. The battery according to claim 1, characterized in that, the outer diameter of the wound core is adapted to the inner diameter of the housing. The size of the separator is respectively larger than the size of the positive electrode sheet and the negative electrode tab. At the upper end of the wound core, the separator protrudes axially along the wound core beyond the positive electrode tab and the negative electrode tab, and the top end of the separator fits against the side of the cap assembly close to the wound core.

6. The battery according to claim 5, characterized in that, the cap assembly includes an end cap, a sealing ring, and an isolation ring. The end cap passes through the sealing ring and is connected to the positive electrode tab, and the end cap seals the opening of the sealing ring through the sealing ring. The positive electrode tab is connected to the end cap, and the isolation ring is disposed between the top of the wound core and the sealing ring. The top of the wound core fits against the side of the isolation ring facing away from the sealing ring.

7. The battery according to claim 6, characterized in that, a connecting portion protrudes from the circumferential portion of the sealing ring towards the side away from the wound core, and the sealing ring is connected to the upper end of the housing in an interference fit through the connecting portion.

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