Cylindrical battery

Abstract

The utility model relates to a cylindrical battery. The cylindrical battery comprises a shell, a battery cell, a cap and a sealing ring, an opening is formed in one end of the shell; the battery cell is accommodated in the shell, the battery cell comprises a body and a tab, the tab is electrically connected with the body, and the tab is positioned on one side, close to the opening, of the body; the cap covers the opening, and the cap is electrically connected with the tab; the sealing ring is sleeved outside the cap, the cap is connected with the shell in a sealing manner through the sealing ring, the sealing ring is provided with an extension part extending towards the body, and the extension part is arranged between the tab and the shell in a separating manner. According to the scheme provided by the invention, short circuit between the tabs and the shell can be avoided, so that the thermal runaway phenomenon of the battery is avoided.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and particularly to cylindrical batteries. Background Art

[0002] In existing cylindrical batteries, the battery cell is usually arranged inside the outer shell, and the cap is connected to the outer shell through an insulating material. The battery cell needs to be provided with a tab welded to the cap. Since the tab needs to have a design redundancy, the tab needs to be folded back on the side close to the cap, resulting in the tab being easily in contact with the outer shell. The polarity of the tab welded to the cap is opposite to that of the outer shell. When the head of the tab is too long, the tab will contact the outer shell to form a short circuit between the positive and negative electrodes, resulting in a thermal runaway phenomenon of the battery; when the position of the bent portion at the folded-back part of the tab is deviated, the bent portion is also easily in contact with the outer shell to form a short circuit between the positive and negative electrodes, resulting in a thermal runaway phenomenon of the battery. Summary of the Utility Model

[0003] To solve or partially solve the problems existing in the related art, this application provides a cylindrical battery that can avoid short circuits between the tabs and the outer shell.

[0004] In the first aspect of this application, a cylindrical battery is provided, which includes an outer shell, a battery cell, a cap, and a sealing ring; an opening is provided at one end of the outer shell; the battery cell is accommodated inside the outer shell, the battery cell includes a body and a tab, the tab is electrically connected to the body, and the tab is located on the side of the body close to the opening; the cap covers the opening, and the cap is electrically connected to the tab; the sealing ring is sleeved outside the cap, and the cap is hermetically connected to the outer shell through the sealing ring. The sealing ring is provided with an extension portion extending towards the body, and the extension portion is interposed between the tab and the outer shell.

[0005] Further, the tab includes a first section, a bent portion, and a second section. The bent portion is respectively connected to the first section and the second section. The first section extends from the body towards the outer shell. One end of the first section far from the body is folded back to form the bent portion. The second section extends from the bent portion towards the outer shell, and the extending direction of the second section is opposite to that of the first section.

[0006] Further, in the extending direction of the first section, the extension portion is located between the bent portion and the outer shell.

[0007] Further, in the extending direction of the second section, the extension portion is located between the outer shell and the end of the second section far from the bent portion.

[0008] Further, the extension portion is annular, and the extension portion surrounds the tab.

[0009] Further, the length of the extension portion along the axial direction of the battery cell is 1.1 - 1.3 mm.

[0010] Further, the thickness of the extension portion is 0.2 - 0.4 mm.

[0011] Further, the cap includes a top cover, the top cover is electrically connected to the tab, the sealing ring surrounds the top cover, the top cover is provided with a contact, the contact protrudes away from the body, and the contact protrudes out of the housing.

[0012] Further, the cap further includes a thermistor, an explosion-proof valve and a current cut-off device connected in sequence, the top cover is connected to the thermistor, the current cut-off device is connected to the tab, and the sealing ring is sleeved outside the thermistor and the explosion-proof valve.

[0013] Further, the cap further includes an insulating ring, the insulating ring is sleeved outside the current cut-off device, and two end faces of the insulating ring respectively abut against the tab and the explosion-proof valve.

[0014] The technical solution provided by this application may include the following beneficial effects: By sleeving the sealing ring outside the cap, the cap is hermetically connected to the housing through the sealing ring. The sealing ring is provided with an extension portion extending towards the body. The extension portion is used to separate the tab from the housing, prevent the tab from contacting the housing, avoid short circuit between the tab and the housing, and prevent the battery from generating a thermal runaway phenomenon.

[0015] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] By describing the exemplary embodiments of the present application in more detail in conjunction with the drawings, the above and other objects, features and advantages of the present application will become more obvious. Among them, in the exemplary embodiments of the present application, the same reference numerals generally represent the same components.

[0017] Figure 1 is a schematic structural diagram of a cylindrical battery shown in an embodiment of the present application.

[0018] Reference numerals: housing 1; opening 11; inner cavity 12; battery cell 2; body 21; tab 22; first section 221; bending portion 222; second section 223; cap 3; top cover 31; contact 311; thermistor 32; explosion-proof valve 33; current cut-off device 34; insulating ring 35; sealing ring 4; extension portion 41. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] Embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present application will be more thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0020] It should be understood that although the terms "first", "second", "third", etc. may be used in the present application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0021] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0022] Unless otherwise clearly defined and limited, the terms "mounted", "connected", "connected to", "fixed" and other terms should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may 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 application can be understood according to specific circumstances.

[0023] In view of the above problems, an embodiment of the present application provides a cylindrical battery, which can avoid short circuit between the tab and the outer shell.

[0024] The technical solutions of the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0025] Figure 1 is a schematic structural diagram of the cylindrical battery shown in the embodiment of the present application.

[0026] See Figure 1, The cylindrical battery includes a housing 1, a battery cell 2, a cap 3, and a sealing ring 4. The housing 1 is cylindrical. One end of the housing 1 is provided with an opening 11. An inner cavity 12 is provided inside the housing 1, and the inner cavity 12 communicates with the opening 11. The battery cell 2 is received in the inner cavity 12. The battery cell 2 includes a body 21 and a tab 22. The tab 22 is electrically connected to the body 21. The tab 22 extends outward from the body 21. The tab 22 is located on the side of the body 21 close to the opening 11. The tab 22 is a positive tab 22, and the housing 1 is connected to the negative electrode of the body 21.

[0027] The cap 3 is located at the opening 11. The cap 3 can cover the opening 11. The cap 3 is electrically connected to the tab 22. The cap 3 is connected to the positive electrode of the body 21. The sealing ring 4 is sleeved outside the cap 3, and the sealing ring 4 is attached to the outer side surface of the cap 3. The outer side surface of the sealing ring 4 is attached to the inner side surface of the housing 1. The cap 3 is hermetically connected to the housing 1 through the sealing ring 4, and external gas and liquid cannot enter the inner cavity 12 through the opening 11. The sealing ring 4 is made of insulating plastic to prevent the cap 3 and the housing 1 from short-circuiting. The sealing ring 4 is provided with an extension portion 41 extending towards the body 21. The extension portion 41 is interposed between the tab 22 and the housing 1, and the tab 22 will not contact the housing 1.

[0028] In this application, by sleeving the sealing ring 4 outside the cap 3, the cap 3 is hermetically connected to the housing 1 through the sealing ring 4. The sealing ring 4 is provided with an extension portion 41 extending towards the body 21. The extension portion 41 is used to separate the tab 22 and the housing 1, preventing the tab 22 from contacting the housing 1, avoiding a short circuit between the tab 22 and the housing 1, and preventing the battery from generating a thermal runaway phenomenon.

[0029] The tab 22 includes a first section 221, a bent portion 222, and a second section 223. The bent portion 222 is connected to the first section 221 and the second section 223 respectively. The first section 221 extends from the body 21 towards the housing 1. One end of the first section 221 away from the body 21 is folded back to form the bent portion 222. The second section 223 extends from the bent portion 222 towards the housing 1. The extending direction of the second section 223 is opposite to that of the first section 221. The second section 223 is welded to the cap 3. The second section 223 does not contact the body 21. The second section 223 is on the side of the first section 221 away from the body 21.

[0030] In some embodiments, the extension portion 41 is arc-shaped. The distance between the end of the second section 223 away from the bent portion 222 and the housing 1 is smaller, and the distance between the end portion of the second section 223 and the housing 1 is larger. In order to prevent the bent portion 222 from short-circuiting with the housing 1, the extension portion 41 is arranged in the extending direction of the first section 221. The extension portion 41 is located between the bent portion 222 and the housing 1. The extension portion 41 can prevent the bent portion 222 from contacting the housing 1, thereby ensuring that the tab 22 will not short-circuit with the housing 1.

[0031] In some embodiments, the extension portion 41 is arc-shaped. The distance between one end of the second segment 223 away from the bending portion 222 and the outer shell 1 is relatively large, while the distance between the bending portion 222 and the outer shell 1 is relatively small. To prevent a short circuit between the bending portion 222 and the outer shell 1, in the extending direction of the second segment 223, the extension portion 41 is located between the outer shell 1 and one end of the second segment 223 away from the bending portion 222. The extension portion 41 can prevent the second segment 223 from contacting the outer shell 1, thereby ensuring that the tab 22 does not short-circuit with the outer shell 1.

[0032] In some embodiments, the extension portion 41 is ring-shaped and surrounds the tab 22. For the case where the second segment 223 is relatively long and there is a risk that one end of the second segment 223 away from the bending portion 222 and the bending portion 222 may contact the outer shell 1, the extension portion 41 can completely separate the tab 22 from the outer shell 1. Even if the battery shakes and the tab 22 is displaced relative to the outer shell 1, the ring-shaped extension portion 41 can ensure that the tab 22 will not contact the outer shell 1 at all, thereby ensuring that the tab 22 does not short-circuit with the outer shell 1.

[0033] The length of the extension portion 41 along the axial direction of the battery cell 2 is 1.1 - 1.3 mm. Preferably, the length of the extension portion 41 along the axial direction of the battery cell 2 is 1.2 mm. The extension portion 41 within this length range can ensure that the tab 22 is completely separated from the outer shell 1. The thickness of the extension portion 41 is 0.2 - 0.4 mm. Preferably, the thickness of the extension portion 41 is 0.3 mm, ensuring that the extension portion 41 has sufficient thickness to prevent the tab 22 from scratching the extension portion 41 without occupying too much space inside the outer shell 1.

[0034] The cap 3 includes a top cover 31. The top cover 31 is electrically connected to the tab 22. The sealing ring 4 surrounds the top cover 31. The top cover 31 is provided with a contact 311 that protrudes in a direction away from the body 21. The contact 311 protrudes from the outer shell 1 and is used to connect a wire or an electrical appliance.

[0035] The cap 3 further includes a thermistor 32, an explosion-proof valve 33, and a current cut-off device 34 that are connected in sequence. The top cover 31 is connected to the thermistor 32, and the current cut-off device 34 is connected to the tab 22. The sealing ring 4 is sleeved outside the thermistor 32 and the explosion-proof valve 33. When the temperature of the battery is too high, the thermistor 32 can block the electrical connection between the battery cell 2 and the top cover 31. When the internal pressure of the outer shell 1 is too high, the explosion-proof valve 33 can release the pressure of the gas inside the outer shell 1. When the temperature of the battery is too high, the current cut-off device 34 can self-destruct, thereby disconnecting the electrical connection between the battery cell 2 and the top cover 31 and the external electrical appliance.

[0036] The cap 3 further includes an insulating ring 35 which is sleeved outside the current cut-off device 34. The two end faces of the insulating ring 35 respectively abut against the tab 22 and the explosion-proof valve 33. The insulating ring 35 can support and position the current cut-off device 34, and can also position the tab 22 to ensure the stable connection between the tab 22 and the current cut-off device 34.

[0037] The solutions of the present application have been described in detail above with reference to the accompanying drawings. In the above embodiments, the descriptions of the various embodiments have their respective emphases. For the parts not described in detail in a certain embodiment, reference may be made to the relevant descriptions of other embodiments. Those skilled in the art should also know that the actions and modules involved in the specification are not necessarily essential to the present application. In addition, it can be understood that the steps in the method embodiments of the present application can be adjusted, combined, and deleted according to actual needs, and the modules in the device embodiments of the present application can be combined, divided, and deleted according to actual needs.

[0038] The various embodiments of the present application have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, the practical application, or the improvement of the technology in the market, or to enable other ordinary skilled in the art in the technical field to understand the disclosed embodiments.

Claims

1. A cylindrical battery, characterized in that: include: A shell, one end of which is provided with an opening; A battery cell, the battery cell is accommodated in the shell, the battery cell comprises a body and a tab, the tab is electrically connected to the body, and the tab is located on a side of the body close to the opening; A cap, the cap covers the opening, and the cap is electrically connected to the tab; A sealing ring is sleeved outside the cap, the cap is sealed and connected to the shell through the sealing ring, and the sealing ring is provided with an extension portion extending toward the body, and the extension portion is separated between the pole ear and the shell.

2. The cylindrical battery according to claim 1, characterized in that: The pole ear includes a first section, a bending portion and a second section, the bending portion is connected to the first section and the second section respectively, the first section extends from the main body toward the shell, one end of the first section away from the main body is folded back to form the bending portion, the second section extends from the bending portion to the shell, and the extension direction of the second section is opposite to the extension direction of the first section.

3. The cylindrical battery according to claim 2, characterized in that: The extending portion is in an extending direction of the first section, and the extending portion is located between the bending portion and the housing.

4. The cylindrical battery according to claim 2, characterized in that: The extending portion is in an extending direction of the second section, and is located between the housing and an end of the second section away from the bending portion.

5. The cylindrical battery according to claim 2, characterized in that: The extension portion is annular and surrounds the pole ear.

6. The cylindrical battery according to claim 1, characterized in that: The length of the extension portion along the axial direction of the battery core is 1.1 to 1.3 mm.

7. The cylindrical battery according to claim 1, characterized in that: The thickness of the extension portion is 0.2-0.4 mm.

8. The cylindrical battery according to claim 1, characterized in that: The cap includes a top cover, the top cover is electrically connected to the tab, the sealing ring is surrounded by the top cover, the top cover is provided with a contact, the contact protrudes in a direction away from the body, and the contact protrudes from the shell.

9. The cylindrical battery according to claim 8, characterized in that: The cap also includes a thermistor, an explosion-proof valve and a current cut-off device which are connected in sequence. The top cover is connected to the thermistor, the current cut-off device is connected to the tab, and the sealing ring is sleeved outside the thermistor and the explosion-proof valve.

10. The cylindrical battery according to claim 9, characterized in that: The cap further comprises an insulating ring, which is sleeved outside the current cut-off device, and two end surfaces of the insulating ring respectively abut against the pole ear and the explosion-proof valve.

Images