Batteries, battery modules and battery packs

Abstract

The present invention relates to the field of battery technology, and discloses a battery, a battery module and a battery pack, wherein the battery comprises a packaging film, a pole group, an external pole ear and an internal pole ear. In a battery of this structure, the internal pole ear comprises a first connection part and a second connection part, wherein the first connection part is electrically connected to the external pole ear, and the second connection part extends inwardly toward the pole group and is connected to the packaging film. When the battery bulges, the packaging film bulges outwardly, the second connection part is connected to the packaging film, the packaging film pulls the second connection part outwardly, and the second connection part pulls the first connection part outwardly synchronously, so that the first connection part moves away from the external pole ear, thereby disconnecting the first connection part from the external pole ear, so as to disconnect the internal pole ear from the external pole ear. When the battery bulges, the electrical connection between the inside and the outside of the battery can be disconnected, thereby effectively improving 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, a battery module and a battery pack. Background Art

[0002] Soft-pack batteries have advantages such as high specific energy, small size and light weight, so they have a large application market. Soft-pack batteries mainly include tabs, pole groups and packaging films. The packaging films package the pole groups and tabs and seal them by hot pressing. Existing soft-pack batteries lack safety protection measures when bulging occurs, resulting in low safety performance of soft-pack batteries. Summary of the invention

[0003] In view of this, the present invention provides a battery, a battery module and a battery pack to solve the problem of low safety of batteries in the prior art when bulging occurs.

[0004] In a first aspect, the present invention provides a battery, comprising:

[0005] Encapsulation film;

[0006] A pole group, disposed in the packaging film;

[0007] An external tab, one end of which is disposed in the packaging film and the other end of which extends outward from the packaging film;

[0008] An internal pole ear is arranged in the packaging film, one end of the internal pole ear is electrically connected to the pole group, and the other end extends away from the pole group to form a first connection part, the first connection part is bent at one end away from the pole group and extends toward the pole group to form a second connection part, the first connection part is electrically connected to the external pole ear, and the second connection part is connected to the packaging film; in the bulging state of the battery, the packaging film bulges outward and pulls the second connection part, and the second connection part pulls the first connection part to disconnect the first connection part from the electrical connection with the external pole ear.

[0009] Beneficial effect: The internal pole ear of the battery with this structure includes a first connecting part and a second connecting part, the first connecting part is electrically connected to the external pole ear, the second connecting part extends inward toward the pole group and is connected to the packaging film, when the battery bulges, the packaging film bulges outward, the second connecting part is connected to the packaging film, the packaging film pulls the second connecting part outward, and the second connecting part simultaneously pulls the first connecting part outward to move the first connecting part away from the external pole ear, thereby disconnecting the first connecting part from the external pole ear to disconnect the electrical connection between the internal pole ear and the external pole ear. When the battery bulges, the electrical connection between the inside and the outside of the battery can be disconnected, effectively improving the safety performance of the battery.

[0010] In an optional embodiment, in the length direction of the external pole lug, the first connecting portion is stacked with the external pole lug, and a side of the first connecting portion facing the external pole lug is attached to the surface of the external pole lug.

[0011] Beneficial effects: The contact area between the first connecting portion and the external pole ear can be increased, thereby ensuring the electrical connection between the two and ensuring that the electric energy of the pole group is effectively transmitted to the outside of the battery through the internal pole ear and the external pole ear.

[0012] In an optional embodiment, along the length direction of the external tab, the length of the first connecting portion and the stacking area of ​​the external tab is L1, 1mm≤L1≤8mm.

[0013] Beneficial effect: The length of the first connection portion and the external tab stacking region is moderate, which can effectively ensure the electrical connection effect between the first connection portion and the external tab, and avoid the waste of tab material caused by the excessive length of the internal tab. In addition, the length of the first connection portion and the external tab stacking region is moderate, and the space occupied by it in the packaging film in the length direction of the battery is moderate, which can effectively improve the space utilization and volume energy density of the battery.

[0014] In an optional embodiment, 3mm≤L1≤5mm.

[0015] In an optional embodiment, the first connecting portion is welded to a surface of the external electrode tab that faces the first connecting portion;

[0016] And / or, the second connection portion is bonded or hot-melt connected to the packaging film.

[0017] Beneficial effect: The first connection portion is welded to the side facing the external pole ear, and the first connection portion and the external pole ear have a good connection effect, which can effectively ensure the conductive effect between the two.

[0018] In an optional embodiment, the second connecting portion extends inwardly to the outside of the large surface of the electrode group, and two surfaces of the second connecting portion in the thickness direction are respectively attached to the packaging film and the outside of the large surface of the electrode group.

[0019] Beneficial effect: The second connection part extends inwardly to the outside of the large surface of the electrode group, so that the second connection part is close to the inside of the electrode group, so that when the battery is bulging, the packaging film can effectively pull the second connection part outward to ensure the pulling effect on the second connection part and the first connection part. At the same time, the second connection part extends inwardly to the outside of the large surface of the electrode group, so that the second connection part is away from the connection position of the first connection part and the external pole ear in the length direction of the battery. The connection position of the second connection part and the packaging film is arranged on both sides of the end surface of the electrode group opposite to the connection position of the first connection part and the external pole ear, which can effectively improve the pulling effect of the second connection part on the first connection part.

[0020] In an optional embodiment, along the length direction of the external electrode ear, the length of the stacking area of ​​the second connecting portion and the electrode group is L2, 5mm≤L2≤25mm.

[0021] Beneficial effects: The length of the stacking area between the second connecting part and the electrode group is moderate, and the length of the second connecting part extending into the interior of the electrode group is moderate, which can effectively ensure the pulling effect on the second connecting part when the packaging film bulges, and then ensure the pulling effect on the first connecting part, and ensure that the first connecting part is effectively separated from the external electrode ear; at the same time, the length of the second connecting part extending into the interior of the electrode group is moderate, so the length of the second connecting part is moderate, which will not make the length of the internal electrode ear too long, avoiding material waste and cost increase; in addition, the length of the second connecting part is moderate, and the internal space of the battery it occupies is moderate, which can effectively ensure the volume grouping efficiency of the battery.

[0022] In an optional embodiment, 10 mm ≤ L2 ≤ 20 mm.

[0023] In a second aspect, the present invention further provides a battery module, comprising any one of the above-mentioned batteries. The battery module comprises a battery, and has the same technical effect as the battery, which will not be described in detail here.

[0024] In a third aspect, the present invention further provides a battery pack, comprising the above-mentioned battery module. The battery pack comprises a battery, and has the same technical effect as the battery, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A schematic diagram of a battery in a normal state according to an embodiment of the present invention;

[0027] Figure 2 is a schematic diagram of a battery according to an embodiment of the present invention;

[0028] Figure 3 A schematic diagram of a battery in a normal state according to an embodiment of the present invention;

[0029] Figure 4 for Figure 3 A partial enlarged view of the middle A part;

[0030] Figure 5A schematic diagram of a battery with double-sided tabs in a bulging state according to an embodiment of the present invention;

[0031] Figure 6 A schematic diagram of a battery with double-sided tabs according to an embodiment of the present invention;

[0032] Figure 7 Schematic diagram of a battery with a single-side tab according to an embodiment of the present invention.

[0033] Description of reference numerals:

[0034] 1. Packaging film; 2. Pole group; 3. External pole ear; 4. Internal pole ear; 41. First connecting part; 42. Second connecting part; 43. Third connecting part; 44. Bending part; 5. Bulging cavity; 6. Welding area; 7. Fixing area; 8. Pole ear glue; 9. Packaging line. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0036] Combine the following Figures 1 to 7 , describing an embodiment of the present invention.

[0037] According to an embodiment of the present invention, on the one hand, a battery is provided, including a packaging film 1, a pole group 2, an external pole tab 3 and an internal pole tab 4.

[0038] Among them, the electrode group 2 is arranged in the packaging film 1; one end of the external electrode ear 3 is arranged in the packaging film 1, and the other end extends outward from the packaging film 1; the internal electrode ear 4 is arranged in the packaging film 1, one end of the internal electrode ear 4 is electrically connected to the electrode group 2, and the other end extends away from the electrode group 2 to form a first connection part 41, and the first connection part 41 is bent at one end away from the electrode group 2 and extends toward the electrode group 2 to form a second connection part 42, the first connection part 41 is electrically connected to the external electrode ear 3, and the second connection part 42 is connected to the packaging film 1; in the bulging state of the battery, the packaging film 1 bulges outward and pulls the second connection part 42, and the second connection part 42 pulls the first connection part 41, so that the first connection part 41 is disconnected from the electrical connection with the external electrode ear 3.

[0039] The battery of this structure has an internal pole ear 4 including a first connecting portion 41 and a second connecting portion 42, wherein the first connecting portion 41 is electrically connected to the external pole ear 3, and the second connecting portion 42 extends inward toward the pole group 2 and is connected to the packaging film 1. When the battery bulges, the packaging film 1 bulges outward, the second connecting portion 42 is connected to the packaging film 1, the packaging film pulls the second connecting portion 42 outward, and the second connecting portion 42 simultaneously pulls the first connecting portion 41 outward to move the first connecting portion 41 away from the external pole ear 3, thereby disconnecting the first connecting portion 41 from the external pole ear 3 to disconnect the internal pole ear 4 from the external pole ear 3. This can disconnect the internal and external electrical connections of the battery when the battery bulges, thereby effectively improving the safety performance of the battery.

[0040] Optionally, in some embodiments, Figure 1 As shown, in the length direction of the external pole lug 3 (i.e., the length direction of the battery), the first connecting portion 41 and the external pole lug 3 are stacked, and the side of the first connecting portion 41 facing the external pole lug 3 is attached to the surface of the external pole lug 3 to increase the contact area between the first connecting portion 41 and the external pole lug 3, thereby ensuring the electrical connection effect between the two and ensuring that the electric energy of the pole group 2 is effectively transferred to the outside of the battery through the internal pole lug 4 and the external pole lug 3.

[0041] like Figure 1 As shown, the external pole lug 3 extends along the length direction of the pole group 2, the first connecting portion 41 is parallel to the external pole lug 3, and the first connecting portion 41 and the external pole lug 3 are in contact with each other on their facing sides to ensure the electrical connection effect between the two.

[0042] If the length of the stacking area between the first connection portion 41 and the external pole ear 3 is too short, the electrical connection between the two cannot be guaranteed; if the length of the stacking area between the first connection portion 41 and the external pole ear 3 is too long, the internal pole ear 4 needs to be reserved for a long time, which will cause material waste and significantly increase the material cost of battery production; at the same time, the pole group 2 cannot be set in the stacking area between the first connection portion 41 and the external pole ear 3, and the length of the stacking area between the first connection portion 41 and the external pole ear 3 is too long, which will lead to low space utilization of the battery, thereby reducing the volume energy density of the battery. In order to avoid this problem, in some embodiments, such as Figure 1 As shown, along the length direction of the external pole lug 3, the length of the first connection portion 41 and the stacking area of ​​the external pole lug 3 is L1, 1mm≤L1≤8mm. The length of the stacking area of ​​the first connection portion 41 and the external pole lug 3 is moderate, which can effectively ensure the electrical connection effect between the first connection portion 41 and the external pole lug 3, and avoid the waste of pole lug materials caused by the excessive length of the internal pole lug 4. In addition, the length of the stacking area of ​​the first connection portion 41 and the external pole lug 3 is moderate, and the space occupied by it in the length direction of the battery is moderate, which can effectively improve the space utilization and volume energy density of the battery.

[0043] Optionally, in some embodiments, the length L1 of the stacking area between the first connecting portion 41 and the external pole ear 3 satisfies 3mm≤L1≤5mm, so as to further optimize the length range of the stacking area between the first connecting portion 41 and the external pole ear 3, further ensure the electrical connection effect between the two, avoid the waste of materials and increase in battery manufacturing costs due to the excessive length of the internal pole ear 4, and further improve the volume energy density of the battery.

[0044] Optionally, in some embodiments, the first connection portion 41 is welded to the side facing the external pole lug 3, and the first connection portion 41 and the external pole lug 3 have a good connection effect, which can effectively ensure the conductive effect between the two. The welding strength between the first connection portion 41 and the external pole lug 3 is relatively small, and the welding strength between the two can ensure the electrical connection effect between the two.

[0045] In some other embodiments, the surface of the first connecting portion 41 facing the external pole lug 3 may be vacuumed to ensure effective fit between the two and ensure electrical connection between the internal pole lug 4 and the external pole lug 3 .

[0046] In some embodiments, the second connection part 42 is bonded or hot-melt connected to the packaging film 1, and the second connection part 42 is conveniently and reliably connected to the packaging film 1, which can ensure that when the battery is bulging, the second connection part 42 is stably maintained on the packaging film 1, so that when the packaging film 1 is bulging, the second connection part 42 is effectively pulled outward, so as to ensure the pulling effect of the second connection part 42 on the first connection part 41, and when the battery is out of control and bulging, the internal pole ear 4 and the external pole ear 3 are promptly and effectively disconnected from each other. The connection strength between the second connection part 42 and the packaging film 1 is greater than the connection strength between the first connection part 41 and the external pole ear 3, ensuring that when the packaging film 1 is bulging, when the first connection part 41 is about to be disconnected from the outside, the second connection part 42 can still be stably maintained on the packaging film 1, so that the second connection part 42 follows the packaging film 1 to continue to pull the first connection part 41, so that the first connection part 41 is effectively separated from the external pole ear 3 and the electrical connection between the two is disconnected.

[0047] like Figure 3 and Figure 4 As shown, the welding position of the internal tab 4 and the external tab 3 forms a welding area 6, which is rectangular and can ensure the connection effect between the internal tab 4 and the external tab 3. The connection area between the second connecting portion 42 and the packaging film 1 forms a fixing area 7.

[0048] like Figure 1As shown, in some embodiments, the second connection portion 42 extends inward to the outside of the large surface of the electrode group 2, and the two sides of the second connection portion 42 in the thickness direction are respectively attached to the packaging film 1 and the outside of the large surface of the electrode group 2. Since the bulge in the central area of ​​the battery is generally higher when the battery is bulging, the outward pulling force is relatively large, so the second connection portion 42 is extended inward to the outside of the large surface of the electrode group 2, so that the second connection portion 42 is close to the inside of the electrode group 2, so that when the battery is bulging, the packaging film 1 can effectively pull the second connection portion 42 outward, and the pulling effect on the second connection portion 42 and the first connection portion 41 is ensured. At the same time, the second connecting portion 42 extends inward to the outside of the large surface of the electrode group 2, so that the second connecting portion 42 is away from the connection position between the first connecting portion 41 and the external electrode ear 3 in the length direction of the battery. The connection position between the second connecting portion 42 and the packaging film 1 is arranged on both sides of the end surface of the electrode group 2 opposite to the connection position between the first connecting portion 41 and the external electrode ear 3, which can effectively improve the pulling effect of the second connecting portion 42 on the first connecting portion 41, and ensure that when the battery is abnormal and bulging, the first connecting portion 41 is disconnected from the external electrode ear 3 in a timely and effective manner, thereby ensuring the safety performance of the battery.

[0049] The second connection part 42 extends to the inner side of the electrode group 2 and is stacked with the electrode group 2. If the length of the stacking area between the second connection part 42 and the electrode group 2 is too small, then in the length direction of the battery, the second connection part 42 is located at the edge area of ​​the packaging film 1, which is not conducive to effectively pulling the second connection part 42 when the packaging film 1 bulges; and if the length of the stacking area between the second connection part 42 and the electrode group 2 is too small, the length of the second connection part 42 away from the connection position between the first connection part 41 and the external pole ear 3 is too small, which is not conducive to the second connection part 42 effectively pulling the first connection part 41. If the length of the stacking area between the second connection part 42 and the electrode group 2 is too large, the required length of the internal pole ear 4 is longer, which will lead to material waste and increased cost; at the same time, the second connection part 42 occupies the internal space of the packaging film 1, and the length of the stacking area between the second connection part 42 and the electrode group 2 is longer, which will increase the space occupied by the second connection part 42, and accordingly the volume of the battery will increase, which will affect the volume energy density of the battery. In order to avoid the above problems, Figure 1As shown, in some embodiments, along the length direction of the external pole ear 3, the length of the stacking area between the second connecting portion 42 and the pole group 2 is L2, 5mm≤L2≤25mm, the length of the stacking area between the second connecting portion 42 and the pole group 2 is moderate, and the length of the second connecting portion 42 extending into the interior of the pole group 2 is moderate, which can effectively ensure the pulling effect on the second connecting portion 42 when the packaging film 1 bulges, and then ensure the pulling effect on the first connecting portion 41, and ensure that the first connecting portion 41 is effectively separated from the external pole ear 3; at the same time, the length of the second connecting portion 42 extending into the interior of the pole group 2 is moderate, so the length of the second connecting portion 42 is moderate, which will not make the length of the internal pole ear 4 too long, avoiding material waste and cost increase; in addition, the length of the second connecting portion 42 is moderate, and the internal space of the battery occupied by it is moderate, which can effectively ensure the volume grouping efficiency of the battery.

[0050] Optionally, in some embodiments, the length L2 of the stacking area between the second connecting portion 42 and the pole group 2 satisfies 10mm≤L2≤20mm, and the length of the stacking area between the second connecting portion 42 and the pole group 2 can be further optimized. While ensuring the pulling effect of the second connecting portion 42 on the first connecting portion 41, the length of the second connecting portion 42 can be further reduced, thereby saving the material of the internal pole ear 4 and the space occupied by the internal pole ear 4.

[0051] In other embodiments, the length of the second connection part 42 may also be the same as that of the first connection part 41, or the length of the second connection part 42 may be smaller than that of the first connection part 41. The second connection part 42 is connected to the packaging film 1, and when the packaging film 1 bulges, the second connection part 42 is pulled outward, and the second connection part 42 then pulls the first connection part 41 outward, ensuring that the second connection part 42 can pull the first connection part 41 to disconnect the first connection part 41 from the external pole ear 3.

[0052] like Figure 1As shown, in some embodiments, the internal pole ear 4 is provided at one end of the pole group 2 in the length direction, and the first connecting portion 41 is provided in the middle position of the thickness direction of the end face of the pole group 2. The pole ear sheet of the internal pole ear 4 can be provided separately from the pole sheet, and the pole ear sheet is welded on the pole sheet, or the pole ear sheet can be formed integrally with the pole sheet. Along the thickness direction of the pole group 2, the multiple pole ear sheets on the upper part of the first connecting portion 41 are bent downward and converged to form a group of pole ear sheet groups, and the multiple pole ear sheets on the lower part of the first connecting portion 41 are bent upward and converged to form another group of pole ear sheet groups. After the two groups of pole group 2 sheet groups are welded and converged, they extend toward the length direction of the pole group 2 to form a connecting section of a certain length. The connecting section extends a distance away from the pole group 2 to form the first connecting portion 41, and the end of the first connecting portion 41 away from the pole group 2 is bent upward and then extends a certain distance toward the inside of the pole group 2 to form the second connecting portion 42, and the bending area between the first connecting portion 41 and the second connecting portion 42 is the bending portion 44 of the internal pole ear 4. If the first connection portion 41 is arranged at the top of the end face of the pole group 2, after the bending portion 44 is bent, the second connection portion 42 is attached to the first connection portion 41, or the spacing between the second connection portion 42 and the first connection portion 41 in the thickness direction of the pole group 2 is too small, resulting in a too large bending angle of the bending portion 44, which will affect the strength and service life of the internal pole ear 4. If the first connection portion 41 is arranged at the bottom of the end face of the pole group 2, the space occupied by the bending portion 44 in the thickness direction of the inner cavity of the packaging film 1 after bending is too large, which will reduce the space utilization rate of the battery. To this end, the first connection portion 41 of the present invention is arranged in the middle position of the thickness direction of the end face of the pole group 2, and after the internal pole ear 4 is bent, the second connection portion 42 and the first connection portion 41 are arranged vertically at a certain distance in the thickness direction of the pole group 2, so that the bending portion 44 can be bent in an arc shape, and the bending angle of the bending portion 44 is moderate, which is convenient for the internal pole ear 4 to bend, and at the same time, the strength of the bending portion 44 and the internal pole ear 4 after bending can be ensured.

[0053] like Figure 1 As shown, the two groups of pole tab sheets at the end of the pole group 2 are the third connecting portion 43 of the internal pole tab 4 , and the third connecting portion 43 is electrically connected to the pole group 2 and the first connecting portion 41 .

[0054] In other embodiments, in the length direction of the external pole lug 3, the first connecting portion 41 and the external pole lug 3 may not be stacked. In this case, the electrical connection between the internal pole lug 4 and the external pole lug 3 can be achieved by welding the end of the bending portion 44 to the inner end surface of the internal pole lug 4 facing the pole group 2.

[0055] like Figure 1As shown, the top and bottom surfaces of the electrode group 2 with larger areas are the large surfaces of the electrode group 2, and the packaging film 1 outside the large surface of the electrode group 2 is smooth and flat. A first step protruding toward the outside of the large surface of the electrode group 2 is provided at the packaging film 1 outside the second connecting portion 42, and the second connecting portion 42 is accommodated inside the first step. The second step extends to the outside of the bending portion 44, then bends and extends downward, and finally extends horizontally for a distance to form a first top sealing area. The packaging film 1 on the bottom surface of the electrode group 2 passes over the end of the electrode group 2, bends and extends upward, and then extends horizontally for a distance to form a second top sealing area.

[0056] like Figure 3 As shown, the internal electrode tab 4 includes an internal positive electrode tab and an internal negative electrode tab, and the external electrode tab 3 includes an external positive electrode tab and an external negative electrode tab.

[0057] In some embodiments, the internal negative electrode tab is a tab of conventional structure, and the internal negative electrode tab is directly welded to the external negative electrode tab. The internal positive electrode tab includes a first connection portion 41, a second connection portion 42, a third connection portion 43 and a bending portion 44, and the first connection portion 41 of the internal positive electrode tab is welded to the external positive electrode tab.

[0058] In other embodiments, the internal negative electrode tab includes a first connection portion 41, a second connection portion 42, a third connection portion 43 and a bending portion 44, and the first connection portion 41 of the internal negative electrode tab is welded to the external negative electrode tab. The internal positive electrode tab is a tab of conventional structure, and the internal positive electrode tab is directly welded to the external positive electrode tab.

[0059] In other embodiments, the internal positive electrode tab and the external positive electrode tab may also be bent, and both the internal positive electrode tab and the external positive electrode tab include a first connection portion 41, a second connection portion 42, a third connection portion 43 and a bent portion 44, the first connection portion 41 of the internal positive electrode tab is welded to the external positive electrode tab, and the first connection portion 41 of the internal negative electrode tab is welded to the external negative electrode tab.

[0060] like Figures 1 to 3 As shown, after the packaging film 1 is hot-pressed and packaged, a packaging line 9 is formed around the electrode group 2. The battery also includes a pole ear glue 8, which is arranged on both sides of the external pole ear 3 in the thickness direction. After the packaging film 1 is pressed, the pole ear glue 8 adheres and fixes the external pole ear 3 to the packaging film 1 to ensure the connection strength between the external pole ear 3 and the packaging film 1 and the sealing at the external pole ear 3. The pole ear glue 8 is arranged at the first top sealing area and the second top sealing area.

[0061] Optionally, in some embodiments, both the external positive electrode tab and the external negative electrode tab are provided with tab glue 8 .

[0062] like Figure 6 As shown, the battery can have tabs on both sides; or Figure 7 As shown, the battery has a terminal lug on one side.

[0063] like Figure 1 As shown, in the normal working state of the battery, the first connecting portion 41 is attached to the external pole lug 3 and welded to the external pole lug 3. Figure 2 As shown in FIG. 1 , when the battery is abnormal and bulges, the packaging film 1 bulges outward and pulls the second connection portion 42, and the second connection portion 42 pulls the bending portion 44 and the first connection portion 41 to separate the first connection portion 41 from the external pole ear 3, thereby disconnecting the connection between the inner and outer pole ears. After the packaging film 1 bulges, a bulge cavity 5 is formed between the packaging film 1 and the pole group 2. The state of the battery when bulging is as shown in FIG. Figure 5 shown.

[0064] Optionally, in some embodiments, the battery comprises a pouch cell.

[0065] According to an embodiment of the present invention, on the other hand, a battery module is provided, comprising the above-mentioned battery.

[0066] In a battery module of this structure, when a battery inside the battery bulges, the first connecting portion 41 can be disconnected from the external pole ear 3 under the pulling action of the packaging film 1 and the second connecting portion 42, thereby disconnecting the electrical connection between the internal pole ear 4 and the external pole ear 3, so as to disconnect the electrical connection between the inside and the outside of the battery when the battery bulges, thereby effectively improving the safety performance of the battery module.

[0067] According to an embodiment of the present invention, on another aspect, a battery pack is provided, comprising the above-mentioned battery module.

[0068] A battery pack with this structure can disconnect the electrical connection between the inside and outside of the battery when the battery inside it bulges, thereby effectively improving the safety performance of the battery pack.

[0069] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A battery, characterized in that: include: Encapsulation film; A pole group, disposed in the packaging film; An external tab, one end of which is disposed in the packaging film and the other end of which extends outward from the packaging film; An internal pole ear is arranged in the packaging film, one end of the internal pole ear is connected to the pole group, and the other end extends away from the pole group to form a first connection part, the first connection part is bent at one end away from the pole group and then extends toward the pole group to form a second connection part, the first connection part is connected to the external pole ear, and the second connection part is connected to the packaging film; the connection strength between the second connection part and the packaging film is greater than the connection strength between the first connection part and the external pole ear; in the battery bulging state, the packaging film bulges outward and pulls the second connection part, and the second connection part pulls the first connection part, so that the first connection part is disconnected from the electrical connection with the external pole ear; In the length direction of the external pole ear, the first connection portion is stacked with the external pole ear, and a side of the first connection portion facing the external pole ear is attached to the surface of the external pole ear; The first connecting portion is welded to a side of the external tab facing the external tab; Along the length direction of the external tab, the length of the first connecting portion and the stacking area of ​​the external tab is L1, 1mm≤L1≤8mm; The second connecting portion extends inwardly to the outside of the large surface of the electrode group, and two sides of the second connecting portion in the thickness direction are respectively attached to the packaging film and the outside of the large surface of the electrode group; Along the length direction of the external electrode ear, the length of the stacking area of ​​the second connecting portion and the electrode group is L2, 5mm≤L2≤25mm; The internal electrode tab further includes a third connection portion, which is disposed at an end of the electrode group and electrically connects the electrode group and the first connection portion.

2. The battery according to claim 1, characterized in that 3mm≤L1≤5mm.

3. The battery according to claim 1 or 2, characterized in that: The second connection portion is bonded or thermally melted to the packaging film.

4. The battery according to claim 1 or 2, characterized in that: 10mm≤L2≤20mm.

5. A battery module, characterized in that: A battery comprising the battery according to any one of claims 1 to 4.

6. A battery pack, characterized in that: Comprising the battery module as claimed in claim 5.

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