Soft package battery, battery module and battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a soft package battery which comprises a packaging film, a pole group, an internal pole lug, an external pole lug and a connecting piece, the connecting piece is arranged in the packaging film, a first connecting end of the connecting piece is electrically connected with the bending part, a second connecting end of the connecting piece is electrically connected with one side, extending into the packaging film, of the external tab, and the first connecting end is connected with the packaging film; and when the soft package battery is in a bulging state, the packaging film pulls the first connecting end, so that the first connecting end is disconnected from the bending part. According to the soft package battery with the structure, the two ends of the connecting piece are respectively connected with the internal tab and the external tab, the connecting piece is connected with the packaging film, the internal tab is connected with the pole group, and when the soft package battery is inflated and swelled, the bending part is kept fixed relative to the pole group, and the packaging film pulls the first connecting end, so that the first connecting end is disconnected from the bending part; therefore, the connection between the internal tab and the external tab is disconnected, and the safety performance of the soft package battery can be effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a soft-pack 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 the application market of soft-pack batteries is relatively large. A soft-pack battery mainly includes pole ears, a pole group and a packaging film. The packaging film encapsulates the pole group and the pole ears and is sealed by hot pressing. When the existing soft-pack battery bulges, there is a lack of safety protection measures, resulting in low safety performance of the soft-pack battery. Content of the Utility Model

[0003] In view of this, the utility model provides a soft-pack battery, a battery module and a battery pack to solve the problem of low safety when the existing soft-pack battery bulges.

[0004] In a first aspect, the utility model provides a soft-pack battery, including:

[0005] A packaging film;

[0006] A pole group disposed inside the packaging film;

[0007] An internal pole ear, one end of which is electrically connected to the pole group, and the other end is bent towards the side surface of the pole group to form a bent portion, and the bent portion is connected to the pole group;

[0008] An external pole ear, one end of which is exposed outside the packaging film, and the other end extends into the packaging film;

[0009] A connecting member disposed inside the packaging film, a first connection end of the connecting member is electrically connected to the bent portion, a second connection end of the connecting member is electrically connected to one side of the external pole ear extending into the packaging film, and the first connection end is connected to the packaging film; in the bulging state of the soft-pack battery, the packaging film pulls the first connection end to disconnect the connection between the first connection end and the bent portion.

[0010] Beneficial effects: For the soft-pack battery with this structure, both ends of the connecting member are respectively connected to the internal pole ear and the external pole ear, and the connecting member is connected to the packaging film, and the internal pole ear is connected to the pole group. When the soft-pack battery bulges due to gas expansion, the bent portion remains fixed relative to the pole group, and the packaging film pulls the first connection end to disconnect the connection between the first connection end and the bent portion, thereby disconnecting the connection between the internal pole ear and the external pole ear, which can effectively improve the safety performance of the soft-pack battery.

[0011] In an optional embodiment, the bent portion is attached to the large surface of the pole group.

[0012] Beneficial effects: After the internal tab extends along the side surface in the thickness direction of the electrode group and then bends inward towards the large surface of the electrode group, it is convenient for the bent portion to be better fixedly connected to the electrode group, ensuring the connection area between the bent portion and the electrode group, and thus ensuring the connection strength between the first connection end and the electrode group.

[0013] In an optional embodiment, the length of the overlapping region between the first connection end and the bent portion is L1, where 10 mm ≤ L1 ≤ 30 mm; and / or, the length of the overlapping region between the second connection end and the external tab is L2, where 1 mm ≤ L2 ≤ 8 mm.

[0014] Beneficial effects: The length of L1 is appropriate, ensuring the conductive effect between the connecting member and the internal tab, and at the same time avoiding the length of L1 being too long, which can save the material and cost of the internal tab; the length of L2 is appropriate, ensuring the conductive effect between the connecting member and the external tab, and at the same time avoiding the overlapping region between the second connection end and the external tab being too long, resulting in waste of the materials of the connecting member and the external tab.

[0015] In an optional embodiment, 15 mm ≤ L1 ≤ 25 mm; and / or, 3 mm ≤ L2 ≤ 5 mm.

[0016] In an optional embodiment, the first connection end is welded to the bent portion;

[0017] and / or, the second connection end is welded to the external tab.

[0018] Beneficial effects: Welding the first connection end to the bent portion can effectively ensure the conductive effect between the connecting member and the internal tab; welding the second connection end to the external tab can effectively ensure the conductive effect between the connecting member and the external tab.

[0019] In an optional embodiment, an insulating film is provided outside the electrode group, and the bent portion is adhered to the insulating film or heat-melt fixed to the insulating film.

[0020] Beneficial effects: The connection method between the bent portion and the insulating film is simple and reliable.

[0021] In an optional embodiment, the first connection end is adhesively fixed to the encapsulation film or heat-melt fixed to the encapsulation film.

[0022] Beneficial effects: The first connection end is adhesively fixed to the encapsulation film or heat-melt fixed to the encapsulation film to conveniently and firmly connect and fix the first connection end to the encapsulation film.

[0023] In an optional embodiment, tab glue is provided at the connection between the external tab and the encapsulation film.

[0024] Beneficial effects: The tab glue bonds and fixes the tab on the encapsulation film, ensuring the connection strength and sealing performance at the external tab.

[0025] In a second aspect, the present utility model further provides a battery module, including the soft-pack battery described in any one of the above.

[0026] In a third aspect, the present utility model further provides a battery pack, including the above-mentioned battery module. Description of the Drawings

[0027] In order to more clearly illustrate the specific embodiments of the present utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 Schematic diagram of a soft-pack battery with double-sided tab exits in the related art;

[0029] Figure 2 Schematic diagram of a soft-pack battery with single-sided tab exits in the related art;

[0030] Figure 3 Schematic diagram of a soft-pack battery according to an embodiment of the present utility model;

[0031] Figure 4 For Figure 3 Partial enlarged view of part A in

[0032] Figure 5 Schematic diagram of the cooperation of the connecting member with the encapsulation film, internal tab, and external tab in a soft-pack battery according to an embodiment of the present utility model;

[0033] Figure 6 Schematic diagram of the cooperation of the connecting member with the encapsulation film, internal tab, and external tab in a soft-pack battery in a bulged state according to an embodiment of the present utility model.

[0034] Description of the reference numerals:

[0035] 1. Encapsulation film; 2. Electrode group; 3. Internal tab; 31. Bent portion; 4. External tab; 5. Connecting member; 51. First connection end; 52. Second connection end; 6. Tab glue; 7. Welding area; 8. Fixed area; 9. Encapsulation line. Detailed Embodiments

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0037] As Figure 1 and Figure 2 shown, in the related art, there are mainly two ways to take out the pole ears of a soft-pack battery, namely taking out the pole ears on the opposite sides and taking out the pole ears on the same side. The soft-pack battery has advantages such as high specific energy, small volume, and light weight. However, when the existing soft-pack battery bulges, there is a lack of safety protection measures and it is unable to disconnect the connection between the inside and the outside of the pole group, resulting in low safety performance of the soft-pack battery.

[0038] Next, the embodiments of the present utility model will be described in conjunction with Figures 2 to 6 .

[0039] According to an embodiment of the present utility model, on the one hand, a soft-pack battery is provided, which includes a packaging film 1, a pole group 2, an internal pole ear 3, an external pole ear 4, and a connecting member 5.

[0040] Among them, the pole group 2 is arranged inside the packaging film 1; one end of the internal pole ear 3 is electrically connected to the pole group 2, and the other end is bent toward the side of the pole group 2 to form a bent portion 31, and the bent portion 31 is connected to the pole group 2; one end of the external pole ear 4 is exposed outside the packaging film 1, and the other end extends into the packaging film 1; the connecting member 5 is arranged inside the packaging film 1, the first connecting end 51 of the connecting member 5 is electrically connected to the bent portion 31, the second connecting end 52 of the connecting member 5 is electrically connected to one side where the external pole ear 4 extends into the packaging film 1, and the first connecting end 51 is connected to the packaging film 1; in the bulging state of the soft-pack battery, the packaging film 1 pulls the first connecting end 51 to disconnect the connection between the first connecting end 51 and the bent portion 31.

[0041] For the soft-pack battery with this structure, both ends of the connecting member 5 are respectively connected to the internal pole ear 3 and the external pole ear 4, and the connecting member 5 is connected to the packaging film 1, and the internal pole ear 3 is connected to the pole group 2. When the soft-pack battery bulges due to gas swelling, the bent portion 31 remains fixed relative to the pole group 2, and the packaging film 1 pulls the first connecting end 51 to disconnect the connection between the first connecting end 51 and the bent portion 31, thereby disconnecting the connection between the internal pole ear 3 and the external pole ear 4, which can effectively improve the safety performance of the soft-pack battery.

[0042] As Figure 3 and Figure 5As shown, in some embodiments, the bent portion 31 is attached to the large surface of the electrode group 2. The internal tab 3 extends along the side surface in the thickness direction of the electrode group 2 and then bends inward toward the large surface of the electrode group 2, which is convenient for the bent portion 31 to be better fixedly connected to the electrode group 2, ensuring the connection area between the bent portion 31 and the electrode group 2, and thus ensuring the connection strength between the first connection end 51 and the electrode group 2. The connection strength between the first connection end 51 and the encapsulation film 1 and the connection strength between the bent portion 31 and the electrode group 2 are both greater than the connection strength between the first connection end 51 and the bent portion 31. To ensure that when the soft-pack battery bulges and the encapsulation film 1 pulls the first connection end 51, the bent portion 31 can be stably held on the electrode group 2 while the bent portion 31 can be effectively separated from the first connection end 51.

[0043] Optionally, in some embodiments, the length of the overlapping region where the first connection end 51 and the bent portion 31 overlap is L1, 10 mm ≤ L1 ≤ 30 mm. The length of L1 is appropriate, ensuring the conductive effect between the connector 5 and the internal tab 3. At the same time, avoiding the length of L1 being too long can save the material and cost of the internal tab 3; and / or, the length of the overlapping region where the second connection end 52 and the external tab 4 overlap is L2, 1 mm ≤ L2 ≤ 8 mm. The length of L2 is appropriate, ensuring the conductive effect between the connector 5 and the external tab 4. At the same time, avoiding the overlapping region where the second connection end 52 and the external tab 4 overlap being too long can prevent waste of the materials of the connector 5 and the external tab 4.

[0044] Optionally, in some embodiments, 15 mm ≤ L1 ≤ 25 mm; and / or, 3 mm ≤ L2 ≤ 5 mm to further optimize the length dimensions of the overlapping regions where the connector 5 overlaps with the internal tab 3 and the external tab 4.

[0045] In some embodiments, the first connection end 51 and the bent portion 31 are welded, which can effectively ensure the conductive effect between the connector 5 and the internal tab 3. The welding strength between the first connection end 51 and the bent portion 31 only needs to ensure the conductive effect between the two, avoiding the welding strength between the two being too large and affecting the disconnection between the first connection end 51 and the bent portion 31 during bulging. As Figure 4 shown, a welding region 7 is formed at the welding position between the first connection end 51 and the bent portion 31. Optionally, the welding region 7 is rectangular.

[0046] Optionally, the second connection end 52 and the external tab 4 are welded, which can effectively ensure the conductive effect between the connector 5 and the external tab 4. A rectangular welding region 7 is also formed at the welding position between the second connection end 52 and the external tab 4.

[0047] An insulating film is provided outside the electrode assembly 2, and the insulating film provides an insulating and isolating effect outside the electrode assembly 2. The bent portion 31 is bonded to the insulating film, or the bent portion 31 is fixed to the insulating film by hot melting. The connection method between the bent portion 31 and the insulating film is simple and reliable. The connection area between the bent portion 31 and the insulating film is the fixed area 8.

[0048] Optionally, the separator of the soft-pack battery is wound outside the electrode assembly 2 to form an insulating film.

[0049] Optionally, in some embodiments, the first connection end 51 is bonded and fixed to the encapsulation film 1, or the first connection end 51 is fixed to the encapsulation film 1 by hot melting, so as to conveniently and firmly connect and fix the first connection end 51 to the encapsulation film 1.

[0050] As Figure 3 shown, the internal tab 3 includes an internal positive tab and an internal negative tab, and the external tab 4 includes an external positive tab and an external negative tab. The connecting member 5 can be disposed between the internal positive tab and the external positive tab, or the connecting member 5 can also be disposed between the internal negative tab and the external negative tab, or the connecting member 5 can be disposed between the internal and external tabs of the positive and negative electrodes.

[0051] Optionally, in some embodiments, as Figure 3 shown, the connecting member 5 is disposed between the internal positive tab and the external positive tab, and the internal negative tab is directly welded to the external negative tab.

[0052] Optionally, in some embodiments, the soft-pack battery has tabs on the same side. As Figure 3 shown, both the external positive tab and the external negative tab are located at the top of the electrode assembly 2. The internal positive tab is bent and extended along the top surface of the electrode assembly 2, and then bent toward the large surface of the electrode assembly 2 to form the bent portion 31.

[0053] As Figure 5 shown, the encapsulation film 1 is wrapped outside the electrode assembly 2. The connecting member 5 is in a sheet shape, and a first step is provided at the encapsulation film 1 outside the overlapping area of the connecting member 5 and the bent portion 31, and a second step is provided at the encapsulation film 1 in the overlapping area of the connecting member 5 and the external tab 4, so that the encapsulation film 1 is wrapped outside the connecting member 5 and part of the external tab 4.

[0054] As Figure 5 shown, a tab adhesive 6 is provided at the connection between the external tab 4 and the encapsulation film 1, and the tab adhesive 6 bonds and fixes the tab to the encapsulation film 1 to ensure the connection strength and sealing performance at the external tab 4.

[0055] As Figure 3 shown, encapsulation lines 9 are provided on all four sides of the encapsulation film 1, which can effectively ensure the sealing, isolation and protection effects on the internal electrode assembly 2.

[0056] According to an embodiment of the present utility model, on the other hand, a battery module is further provided, which includes a plurality of the above-mentioned soft-pack batteries.

[0057] In the battery module with this structure, when the soft-pack battery inside it bulges due to gas expansion, the bending portion 31 remains fixed relative to the pole group 2, and the encapsulation film 1 pulls the first connection end 51, so that the first connection end 51 disconnects from the bending portion 31, thereby disconnecting the connection between the internal pole ear 3 and the external pole ear 4, which can effectively improve the safety performance of the soft-pack battery and the battery module.

[0058] According to an embodiment of the present utility model, on yet another hand, a battery pack is further provided, which includes the above-mentioned battery module.

[0059] In the battery pack with this structure, when the soft-pack battery bulges due to gas expansion, the connection between the internal pole ear 3 and the external pole ear 4 can be timely and effectively disconnected, which can effectively improve the safety performance of the battery pack.

[0060] Although the embodiments of the present utility model are described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present utility model, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A soft pack battery, characterized in that: include: Encapsulation film; A pole group, disposed in the packaging film; An internal pole ear, one end of which is electrically connected to the pole group, and the other end of which is bent toward the side of the pole group to form a bent portion, and the bent portion is connected to the pole group; An external tab, one end of which is exposed outside the packaging film and the other end of which is inserted into the packaging film; A connector is disposed in the packaging film, wherein a first connecting end of the connector is electrically connected to the bent portion, a second connecting end of the connector is electrically connected to a side of the external pole ear extending into the packaging film, and the first connecting end is connected to the packaging film; when the soft-pack battery is in a bulging state, the packaging film pulls the first connecting end to disconnect the first connecting end from the bent portion.

2. The soft pack battery according to claim 1, characterized in that: The bent portion is attached to the large surface of the pole group.

3. The soft pack battery according to claim 1 or 2, characterized in that: The length of the overlapping area between the first connecting end and the bending portion is L1, 10mm≤L1≤30mm; and / or the length of the overlapping area between the second connecting end and the external pole ear is L2, 1mm≤L2≤8mm.

4. The soft pack battery according to claim 3, characterized in that: 15mm≤L1≤25mm; and / or, 3mm≤L2≤5mm.

5. The soft pack battery according to claim 1 or 2, characterized in that: The first connecting end is welded to the bending portion; And / or, the second connection end is welded to the external electrode tab.

6. The soft pack battery according to claim 1 or 2, characterized in that: An insulating film is disposed outside the electrode group, and the bent portion is bonded to the insulating film, or the bent portion is fixed to the insulating film by hot melting.

7. The soft pack battery according to claim 1 or 2, characterized in that: The first connection end is adhesively fixed on the packaging film, or the first connection end is hot-melt fixed on the packaging film.

8. The soft pack battery according to claim 1 or 2, characterized in that: A tab glue is provided at the connection between the external tab and the packaging film.

9. A battery module, characterized in that: A soft-pack battery comprising the battery described in any one of claims 1 to 8.

10. A battery pack, characterized in that: Comprising the battery module as claimed in claim 9.

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