Battery

Abstract

The present invention provides a battery, comprising a housing, a wound core and an ear structure. The housing has a receiving cavity for receiving the wound core. The wound core includes a positive current collector and a negative current collector. The ear structure includes a positive ear and a negative ear. The positive ear is connected to the positive current collector, and the negative ear is connected to the negative current collector. The positive ear and the negative ear are led out from opposite ends of the wound core. The negative ear has at least two notches extending inwards along the edge of the negative ear. The present invention effectively reduces the risk of internal short circuit of the battery and improves the safety performance of the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery. Background Art

[0002] With the rapid development of social economy, lithium-ion batteries have the advantages of high specific energy, good cycle performance, long life, high working voltage, safety, and no memory effect, and have been widely used in portable electronic devices, energy storage devices, and the drive of electric vehicles. Most of the common batteries such as cylindrical batteries and button batteries use metal casings. In the production and manufacturing process of the battery, the negative electrode tab of the battery will be bent. If the negative electrode tab is not bent well, it will cause the negative electrode tab of the battery to contact the battery core, resulting in an internal short circuit, which will pose a risk of battery explosion in the later use of the battery.

[0003] Currently, the existing negative electrode tabs are usually of a single electrode tab structure, and the materials are generally selected from metals such as nickel or nickel-plated steel. Generally, the negative electrode tab is welded to the negative electrode current collector, and then the negative electrode tab is led out from the end of the battery core and bent, and then welded to the bottom wall of the battery casing.

[0004] However, for the negative electrode tabs in the prior art, since the materials are metals such as nickel or nickel-plated steel, after being bent, they contact the core, easily crush the core, and easily cause poor coverage of the core, thereby causing the problem of internal lithium precipitation and short circuit. At the same time, the bent area of the negative electrode tab is easily damaged, the strength and service life are reduced, and the safety performance of the battery is affected. Summary of the Invention

[0005] An embodiment of the present invention provides a battery, which effectively reduces the risk of internal short circuit of the battery and has high safety performance.

[0006] The present invention provides a battery, including a casing, a core, and an electrode tab structure. The casing has a receiving cavity for receiving the core. The core includes a positive electrode current collector and a negative electrode current collector. The electrode tab structure includes a positive electrode tab and a negative electrode tab. The positive electrode tab is connected to the positive electrode current collector, and the negative electrode tab is connected to the negative electrode current collector. The positive electrode tab and the negative electrode tab are led out from opposite ends of the core. The negative electrode tab has at least two notches extending inward along the edge of the negative electrode tab. Specifically, during the bending process of the negative electrode tab, the negative electrode tab has at least two notches, and the notches extend from the edge of the negative electrode tab into the negative electrode tab. When the negative electrode tab is bent, at least two notches are located at the bending position of the negative electrode tab. It can be understood that through the design of the notches, the contact with the core can be effectively reduced when the negative electrode tab is bent, thereby reducing the risk of internal short circuit of the battery caused by crushing the core and causing poor coverage of the core, and improving the safety performance of the battery.

[0007] For the battery as described above, optionally, at least two notches are located on opposite sides of the negative tab, so that when the negative tab is bent, an inner concave portion with a gap from the winding core is formed, and the inner concave portion is recessed away from the winding core. That is to say, at least two notches are located on opposite sides of the negative tab, and at least two notches are located at corresponding positions on opposite sides of the negative tab.

[0008] It can be understood that there are gaps both in the horizontal and vertical directions between the notches and the winding core. Through the design of the notches, an inner concave portion with a gap from the winding core is formed when the negative tab is bent, and the inner concave portion can effectively prevent the negative tab from contacting the winding core after being bent, effectively reducing the risk of internal short circuit of the battery caused by the negative tab contacting the winding core after being bent and then collapsing the winding core, resulting in poor coverage of the winding core, and improving the safety performance of the battery.

[0009] For the battery as described above, optionally, the edge shape of the notch is arc-shaped; the inner concave portion is arc-shaped, and the inner concave arc surface of the inner concave portion is greater than 1 / 4 of the arc. Specifically, the edge shape of the notch is arc-shaped, which avoids the appearance of sharp corners when the negative tab is bent, reduces the extrusion damage of the negative tab to the winding core, and can better prevent the negative tab from contacting the winding core after being bent. Moreover, the arc-shaped structure can improve the strength and service life of the negative tab without affecting the safety performance of the battery.

[0010] For the battery as described above, optionally, the arc radius of the notch is less than or equal to 1 / 4 of the maximum width of the negative tab. Specifically, the arc radius of the notch is less than 1 / 4 of the maximum width of the negative tab or the arc radius of the notch is equal to 1 / 4 of the maximum width of the negative tab, which can ensure that multiple notches are located on opposite sides of the negative tab and the multiple notches on opposite sides are in a non-connected state.

[0011] For the battery as described above, optionally, at least two notches are symmetrically arranged along both the width and length directions of the negative tab. Specifically, at least two notches are symmetrically arranged along the width direction of the negative tab, and at least two notches are symmetrically arranged along the length direction of the negative tab. When the negative tab is in a bent state, the notches on opposite sides of the negative tab can match each other.

[0012] For the battery as described above, optionally, the height of any part of the winding core is higher than the height where the notch is located. Specifically, after the negative tab is bent, the heights where the notches on opposite sides of the negative tab are located are lower than the height of any part of the winding core. That is to say, the notches on opposite sides of the negative tab are always below the winding core, which can increase the gap between the notches and the winding core, and further can ensure to a greater extent that the negative tab does not contact the winding core after being bent, improving safety.

[0013] For the battery as described above, optionally, the negative tab includes a connecting portion and an extending portion. The connecting portion is disposed on the negative current collector. Specifically, the connecting portion is welded to the negative current collector. The extending portion extends away from the connecting portion and extends above the negative current collector. Opposite ends of the notch are respectively connected to the connecting portion and the extending portion. Specifically, the connecting portion and the extending portion are respectively located on opposite sides of the notch, and opposite ends of the notch are respectively connected to the connecting portion and the extending portion. When the negative tab is in a vertical state, the extending portion extends away from the connecting portion and extends above the negative current collector, and the connecting portion is in contact with and fixedly connected to the negative current collector.

[0014] For the battery as described above, optionally, the distance between the side end of the concave portion of the negative tab near the connecting portion and the core is greater than or equal to the distance between the side end of the concave portion of the negative tab near the extending portion and the core.

[0015] For the battery as described above, optionally, both the extending portion and the connecting portion are flat in shape. Specifically, both the extending portion and the connecting portion are flat in shape, which facilitates bending of the negative tab.

[0016] For the battery as described above, optionally, the width of the negative tab is 2 mm - 4 mm. Specifically, the width of the negative tab is 2 mm - 4 mm, and the width can be determined according to the actual situation, so no more details are provided here.

[0017] Optionally, the battery further includes a case cover. The case and the case cover jointly enclose a receiving cavity. A separator for separating the positive current collector and the negative current collector is provided between the positive current collector and the negative current collector. The negative tab is connected to the bottom wall of the case, and the positive tab is connected to the case cover. Specifically, the case and the case cover jointly enclose a receiving cavity, the core is received in the receiving cavity, a separator for separating the positive current collector and the negative current collector is provided between the positive current collector and the negative current collector, which can maintain good insulation performance. The negative tab is connected to the bottom wall of the case, and the positive tab is connected to the case cover.

[0018] Optionally, the separator is generally a porous membrane such as a polyethylene porous membrane, a polypropylene porous membrane, a composite porous membrane of polyethylene and polypropylene, or a glass fiber membrane. In this embodiment, the positive current collector is made of aluminum foil, and the negative current collector is made of copper foil.

[0019] The battery provided by the present invention includes a housing, a wound core, and an ear structure. The housing has a receiving cavity for accommodating the wound core. The wound core includes a positive current collector and a negative current collector. The ear structure includes a positive ear and a negative ear. The positive ear is connected to the positive current collector, and the negative ear is connected to the negative current collector. The positive ear and the negative ear are led out from opposite ends of the wound core. The negative ear has at least two notches extending inward along the edge of the negative ear. Specifically, during the bending process of the negative ear, the negative ear has at least two notches that extend from the edge of the negative ear into the interior of the negative ear. When the negative ear is bent, at least two notches are located at the bending position of the negative ear. It can be understood that through the design of the notches, the contact with the wound core can be effectively reduced when the negative ear is bent, thereby preventing the collapse of the wound core and the risk of internal short circuit of the battery caused by poor coverage of the wound core, improving the safety performance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 Schematic structural diagram of a battery from a first perspective of the prior art;

[0022] Figure 2 Schematic structural diagram of the connection between the negative ear and the negative current collector in a battery of the prior art;

[0023] Figure 3 Schematic structural diagram of a battery from a second perspective of the prior art;

[0024] Figure 4 Schematic structural diagram of a battery from a first perspective provided by an embodiment of the present application;

[0025] Figure 5 Schematic structural diagram of a battery from a second perspective provided by an embodiment of the present application;

[0026] Figure 6 Schematic structural diagram of a battery from a third perspective provided by an embodiment of the present application;

[0027] Figure 7 Schematic structural diagram of the connection between the negative ear and the negative current collector in a battery provided by an embodiment of the present application;

[0028] Figure 8 Schematic structural diagram of the first type of negative ear in a battery provided by an embodiment of the present application;

[0029] Figure 9Schematic diagram of the second structure of the negative electrode tab in the battery provided by the embodiment of the present application;

[0030] Figure 10 Schematic diagram of the third structure of the negative electrode tab in the battery provided by the embodiment of the present application.

[0031] Explanation of the reference numerals:

[0032] 1 - housing;

[0033] 2 - wound core;

[0034] 10 - battery;

[0035] 22 - negative current collector;

[0036] 3 - tab structure;

[0037] 31 - positive electrode tab;

[0038] 32 - negative electrode tab;

[0039] 321 - notch;

[0040] 322 - connecting portion;

[0041] 323 - extending portion;

[0042] 4 - cell cover. Detailed implementation manners

[0043] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention. All other embodiments obtained fall within the protection scope of the present invention. Without conflict, the following embodiments and the features in the embodiments may be combined with each other.

[0044] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention 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 invention.

[0045] In the present invention, unless otherwise clearly specified and defined, terms such as "installation", "connection", "linkage", "fixation" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral one; it may be a direct connection, or an indirect connection through an intermediate medium, and it may be the communication of the inner cavities of two components or the interaction relationship between two components. 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 circumstances.

[0046] It should be noted that in the description of the present invention, the terms "first", "second", "third" are only used for conveniently describing different cavity components, and cannot be understood as indicating or implying an order relationship, relative importance, or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", "third" may explicitly or implicitly include at least one such feature.

[0047] Figure 1 is a schematic structural diagram of a battery from a first perspective of the prior art, Figure 2 is a schematic structural diagram of the connection between the negative electrode tab and the negative electrode current collector in a battery of the prior art, Figure 3 is a schematic structural diagram of a battery from a second perspective of the prior art, as Figures 1-3 shown, in the prior art, the negative electrode tab is usually a single-pole tab structure, and the material is generally selected from metals such as nickel or nickel-plated steel. Generally, the negative electrode tab is welded to the negative electrode current collector, and then the negative electrode tab is led out from the battery core and bent, and then welded to the bottom wall of the battery housing. However, for the negative electrode tab in the prior art, since the material is nickel or nickel-plated steel, when it is bent and contacts the wound core, it is easy to crush the wound core, which easily causes poor coverage of the wound core, and further causes problems such as internal lithium deposition and short circuit. At the same time, the bent area of the negative electrode tab is easily damaged, the strength and service life are reduced, which affects the safety performance of the battery.

[0048] In order to overcome the defects in the prior art, a battery provided by the present invention can avoid the contact between the negative electrode tab and the wound core after bending through the design of the notch provided on the negative electrode tab, effectively reducing the risk of internal short circuit of the battery and improving the safety performance of the battery.

[0049] The content of the present invention will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can understand the content of the present invention more clearly and in detail.

[0050] Figure 4 is a schematic structural diagram of a battery from a first perspective provided by an embodiment of the present application; Figure 5 is a schematic structural diagram of a battery from a second perspective provided by an embodiment of the present application; Figure 6 is a schematic structural diagram of a battery from a third perspective provided by an embodiment of the present application; Figure 7Schematic diagram of the connection between the negative tab and the negative current collector in the battery provided by the embodiment of the present application; as Figures 4-7 shown, an embodiment of the present application provides a battery 10, including a housing 1, a wound core 2, and a tab structure 3. The housing 1 has a receiving cavity for receiving the wound core 2. The wound core 2 includes a positive current collector and a negative current collector 22. Specifically, the battery 10 includes a housing 1, an electrode core, and a tab structure 3. The electrode core includes a stacked structure, and the stacked structure is wound to form a wound core 2 with a hollow inner hole. The housing 1 has a receiving cavity for receiving the electrode core, that is, the receiving cavity is for receiving the wound core 2.

[0051] Optionally, the battery 10 of this embodiment is not limited to a button battery 10, and can also be applied to a series of batteries 10 with bent negative tabs 32, such as a steel shell battery 10, a square battery 10, etc.

[0052] The tab structure 3 includes a positive tab 31 and a negative tab 32. The positive tab 31 is connected to the positive current collector, and the negative tab 32 is connected to the negative current collector 22. The positive tab 31 and the negative tab 32 are led out from opposite ends of the wound core 2. Specifically, as Figure 2 and Figure 4 shown, the positive tab 31 is led out from the upper end of the wound core 2, and the negative tab 32 is led out from the lower end of the wound core 2 and has been welded to the negative current collector 22. The positive current collector (not shown in the figure) is located on the side close to the positive tab 31, and the positive tab 31 is connected to the positive current collector by welding or in other forms; the negative current collector 22 is located on the side close to the negative tab 32, and the negative tab 32 is connected to the negative current collector 22 by welding or in other forms. Optionally, the negative tab 32 is generally made of metals such as nickel, nickel-plated copper, etc., and the thickness is generally 0.06 - 0.15 mm.

[0053] Optionally, the positive tab 31 is an aluminum strip, and the negative tab 32 is a copper strip, a nickel strip, or a nickel-plated copper strip.

[0054] According to different actual situations, both the positive tab 31 and the negative tab 32 can be led out from one end face of the wound core 2, or can be led out from different end faces, that is, the positive tab 31 is led out from one end face, and the negative tab 32 is led out from the other end face.

[0055] At the end face position of the wound core 2, the positive tab 31 and the negative tab 32 can be led out from the innermost layer, the middle layer, or the outermost layer of the wound core 2. The number of the positive tab 31 and the negative tab 32 led out from the wound core 2 can be one or more, and can be designed according to the actual situation of the wound core 2. In this embodiment, one positive tab 31 and one negative tab 32 are led out from the upper end face and the lower end face of the wound core 2 respectively. The positive tab 31 is located at one end of the upper end face of the wound core 2, and the negative tab 32 is located at one end of the lower end face of the wound core 2.

[0056] The negative tab 32 has at least two notches 321 extending inwards along the edge of the negative tab 32. Specifically, as Figure 6 shown, during the bending process of the negative tab 32, the negative tab 32 has at least two notches 321, and the notches 321 extend from the edge of the negative tab 32 towards the inside of the negative tab 32.

[0057] When the negative tab 32 is being bent, at least two notches 321 are located at the bending position of the negative tab 32. It can be understood that through the design of the notches 321, the contact with the core 2 can be effectively reduced when the negative tab 32 is bent, thereby preventing the core 2 from being crushed and causing the risk of internal short circuit of the battery 10 due to poor coverage of the core 2, improving the safety performance of the battery 10. In some possible embodiments, at least two notches 321 are located on opposite sides of the negative tab 32, so that the negative tab 32 forms a concave portion with a gap from the core 2 when bent, and the concave portion recesses towards the side away from the core 2. That is to say, the concave portion can prevent the negative tab 32 from contacting the core 2 after being bent. At least two notches 321 are located on opposite sides of the negative tab 32, and at least two notches 321 are located at corresponding positions on opposite sides of the negative tab 32.

[0058] It can be understood that there are gaps between the notches 321 and the core 2 in both the horizontal and vertical directions. Through the design of the notches 321, the negative tab 32 forms a concave portion with a gap from the core 2 when bent, and the concave portion can further enhance the prevention of the negative tab 32 from contacting the core 2 after being bent, effectively reducing the risk of internal short circuit of the battery 10 caused by the contact between the negative tab 32 and the core 2 after being bent, thereby crushing the core 2 and causing poor coverage of the core 2, and improving the safety performance of the battery 10.

[0059] Optionally, the negative tab 32 has two notches 321, and each of the opposite sides of the negative tab 32 has one notch 321.

[0060] Optionally, in the bent state, the negative tab 32 is in an "L" shape.

[0061] Specifically, a tab protection adhesive is provided on the tab structure 3. The tab protection adhesive is pasted or provided on the positive tab 31 and the negative tab 32 to play an insulating and protective role. The tab protection adhesive provided on the negative tab 32 is located at the notch 321. Optionally, the width of the tab protection adhesive provided on the negative tab 32 is 0.5 mm - 1.0 mm wider than the width of the negative tab 32.

[0062] In an alternative embodiment, the edge shape of the notch 321 is an arc. Specifically, the edge shape of the notch 321 is an arc, which avoids the appearance of sharp corners when the negative tab 32 is bent, reduces the extrusion damage of the negative tab 32 to the core 2, and can better avoid the contact between the bent negative tab 32 and the core 2. Moreover, the arc-shaped structure can improve the strength and service life of the negative tab 32 and has no impact on the safety performance of the battery 10.

[0063] The concave part is arc-shaped, and the concave arc surface of the concave part is greater than a quarter of a circle. This can better avoid the contact between the bent negative tab 32 and the core 2 and improve the safety performance of the battery 10.

[0064] In an alternative embodiment, the arc radius of the notch 321 is less than or equal to one-fourth of the maximum width of the negative tab 32. Specifically, the arc radius of the notch 321 is less than one-fourth of the maximum width of the negative tab 32 or the arc radius of the notch 321 is equal to one-fourth of the maximum width of the negative tab 32, which can ensure that multiple notches 321 are located on opposite sides of the negative tab 32 and the multiple notches 321 on the opposite sides are in a non-connected state.

[0065] In an alternative embodiment, at least two notches 321 are symmetrically arranged along both the width and length directions of the negative tab 32. Specifically, at least two notches 321 are symmetrically arranged along the width direction of the negative tab 32, and at the same time, at least two notches 321 are symmetrically arranged along the length direction of the negative tab 32. When the negative tab 32 is in a bent state, the notches 321 on opposite sides of the negative tab 32 can match each other.

[0066] Optionally, the cross-section of the notch 321 is greater than or equal to a quarter of a circle. Specifically, the cross-section of the notch 321 is greater than a quarter of a circle, or the cross-section of the notch 321 is equal to a quarter of a circle. Such a design can avoid the contact between the bent negative tab 32 and the core 2, thereby improving the safety performance of the battery 10.

[0067] In an alternative embodiment, the height of any part of the core 2 is higher than the height where the notch 321 is located. Specifically, after the negative tab 32 is bent, the heights where the notches 321 on opposite sides of the negative tab 32 are located are both lower than the height of any part of the core 2. That is to say, the notches 321 on opposite sides of the negative tab 32 are always below the core 2, which can increase the gap between the notch 321 and the core 2, and further can ensure to a greater extent that when the negative tab 32 is bent, it avoids contact with the core 2 and improves safety.

[0068] In an alternative embodiment, the negative electrode tab 32 includes a connecting portion 322 and an extending portion 323. The connecting portion 322 is disposed on the negative electrode current collector 22. Specifically, the connecting portion 322 is welded to the negative electrode current collector 22. The extending portion 323 extends away from the connecting portion 322 and extends above the negative electrode current collector 22. Opposite ends of the notch 321 are respectively connected to the connecting portion 322 and the extending portion 323. Specifically, the connecting portion 322 and the extending portion 323 are respectively located on opposite sides of the notch 321, and opposite ends of the notch 321 are respectively connected to the connecting portion 322 and the extending portion 323. Wherein, when the negative electrode tab 32 is in a vertical state, the extending portion 323 extends away from the connecting portion 322 and extends above the negative electrode current collector 22, and the connecting portion 322 is in contact with and fixedly connected to the negative electrode current collector 22; as Figure 6 shown, when the negative electrode tab 32 is in a bent state, the extending portion 323 extends away from the connecting portion 322 and is connected to the negative electrode of the housing 1. Similarly, after being bent, the positive electrode tab 31 is connected to the positive electrode of the housing 1.

[0069] In an alternative embodiment, the distance between the side end of the concave portion of the negative electrode tab close to the connecting portion 322 and the core 2 is greater than or equal to the distance between the side end of the concave portion of the negative electrode tab close to the extending portion 323 and the core 2. Specifically, referring to Figure 6 , it can better avoid the contact between the negative electrode tab 32 and the core 2 after being bent, and improve the safety performance of the battery 10.

[0070] Optionally, Figure 8 is a schematic structural diagram of the first type of negative electrode tab in the battery provided by the embodiment of the present application. As Figure 8 shown, when the width of the connecting portion 322 is smaller than the width of the extending portion 323, the opening of the notch 321 faces the connecting portion 322. Figure 9 is a schematic structural diagram of the second type of negative electrode tab in the battery provided by the embodiment of the present application. As Figure 9 shown, when the width of the connecting portion 322 is greater than the width of the extending portion 323, the opening of the notch 321 faces the extending portion 323. Moreover, when the width of the connecting portion 322 is smaller than or greater than the width of the extending portion 323, the cross-section of the notch 321 is a circular arc greater than or equal to 1 / 4. Figure 10 is a schematic structural diagram of the third type of negative electrode tab in the battery provided by the embodiment of the present application. As Figure 10 shown, when the width of the connecting portion 322 is equal to the width of the extending portion 323, the cross-section of the notch 321 is a 1 / 2 circular arc.

[0071] In an alternative embodiment, the shapes of both the extending portion 323 and the connecting portion 322 are flat. Specifically, the shapes of both the extending portion 323 and the connecting portion 322 are flat, which facilitates bending of the negative electrode tab 32.

[0072] In an alternative embodiment, the width of the negative tab 32 is 2 mm - 4 mm. Specifically, the width of the negative tab 32 is 2 mm - 4 mm, and the width can be determined according to the actual situation, which will not be elaborated here.

[0073] Optionally, the battery 10 further includes a cover 4. The housing 1 and the cover 4 together define a receiving cavity. A separator for separating the positive current collector and the negative current collector 22 is provided between the positive current collector and the negative current collector 22. The negative tab 32 is connected to the bottom wall of the housing 1, and the positive tab 31 is connected to the cover 4. Specifically, as Figure 5 shown, the negative tab 32 with a notch 321 has been welded. Through the design of the notch 321 of the negative tab 32, when the negative tab 32 is in a bent and welded state, it is prevented from contacting the core 2, thereby improving safety. There are two covers 4, which are respectively connected to the upper and lower ends of the housing 1. The housing 1 and the two covers 4 together define a receiving cavity. The core 2 is received in the receiving cavity. A separator for separating the positive current collector and the negative current collector 22 is provided between the positive current collector and the negative current collector 22, which can maintain good insulation performance. The negative tab 32 is connected to the bottom wall of the housing 1, and the positive tab 31 is connected to the upper cover 4 of the housing 1.

[0074] Optionally, the separator is generally a porous membrane such as a polyethylene porous membrane, a polypropylene porous membrane, a composite porous membrane of polyethylene and polypropylene, or a glass fiber membrane. In this embodiment, the positive current collector is made of aluminum foil, and the negative current collector 22 is made of copper foil.

[0075] The battery provided by the embodiment of the present application includes a housing, a core, and an ear structure. The housing has a receiving cavity for receiving the core. The core includes a positive current collector and a negative current collector. The ear structure includes a positive tab and a negative tab. The positive tab is connected to the positive current collector, and the negative tab is connected to the negative current collector. The positive tab and the negative tab are led out from opposite ends of the core. The negative tab has at least two notches extending inward along the edge of the negative tab. Specifically, during the bending process of the negative tab, the negative tab has at least two notches that extend from the edge of the negative tab into the interior of the negative tab. When the negative tab is bent, at least two notches are located at the bent portion of the negative tab. It can be understood that through the design of the notches, the risk of contacting the core when the negative tab is bent, thereby collapsing the core and causing internal short circuit of the battery due to poor coverage of the core, can be effectively reduced, and the safety performance of the battery can be improved.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A battery, characterized in that, It includes a housing, a winding core, a housing cover and an ear structure. The housing cover and the housing jointly enclose a receiving cavity for accommodating the winding core, and the winding core includes a positive current collector and a negative current collector. The ear structure includes a positive ear and a negative ear. The positive ear is connected to the positive current collector, and the negative ear is connected to the negative current collector. The positive ear and the negative ear extend from opposite ends of the winding core. The negative ear has at least two notches extending inwards along the edge of the negative ear. At least two of the notches are located on opposite sides of the negative ear, so that when the negative ear is bent, an inward concave portion with a gap from the winding core is formed, and the inward concave portion is recessed towards the side away from the winding core. The negative ear includes a connecting portion and an extending portion. The connecting portion is arranged on the negative current collector, and the extending portion extends towards the side away from the connecting portion and extends above the negative current collector. Opposite ends of the notch are respectively connected to the connecting portion and the extending portion. The distance between the side end of the inward concave portion of the negative ear close to the connecting portion and the winding core is greater than or equal to the distance between the side end of the inward concave portion of the negative ear close to the extending portion and the winding core.

2. The battery according to claim 1, characterized in that, The edge shape of the notch is arc-shaped. The inward concave portion is arc-shaped, and the inward concave arc surface of the inward concave portion is greater than 1 / 4 of a circle arc.

3. The battery according to claim 1 or 2, characterized in that, The arc radius of the notch is less than or equal to 1 / 4 of the maximum width of the negative ear.

4. The battery according to claim 1 or 2, characterized in that, At least two of the notches are symmetrically arranged along both the width and length directions of the negative ear.

5. The battery according to claim 1 or 2, characterized in that, The height of any part of the winding core is higher than the height where the notch is located.

6. The battery according to claim 1, characterized in that, The shapes of both the extending portion and the connecting portion are flat.

7. The battery according to claim 1 or 2, characterized in that, The width of the negative ear is 2 mm - 4 mm.

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