Battery and battery pack

Abstract

A battery and a battery pack. The battery comprises a battery cell and a colloid (20), and the battery cell comprises electrode sheets (10) and separators (30), wherein each separator (30) has a first part (320) and second parts (310) along the height direction of the battery cell, the second parts (310) are disposed at two ends of the first part (320), the first part (320) is stacked on an electrode sheet (10), the second parts (310) protrude out from two ends of the electrode sheet (10), a plurality of second parts (310) located at the same end of the electrode sheet (10) are disposed towards a central region of the battery cell along the thickness direction of the battery cell, and the plurality of second parts (310) are bonded by means of the colloid (20) to form an insulating structure disposed on the top surface and the bottom surface of the electrode sheet.

Description

Batteries and battery packs

[0001] This application claims priority to Chinese Patent Application No. 202423194568.X, filed with the Chinese Patent Office on December 23, 2024, the entire contents of which are incorporated herein by reference.

[0002] Technical Field

[0003] This application relates to the field of battery-related technologies, such as a battery and a battery pack.

[0004] Background Technology

[0005] With the continuous development of battery technology, the requirements for battery density are becoming increasingly stringent. In traditional lithium battery technology, the separator, as the insulating medium between the positive and negative electrodes, plays a crucial role in the safety and stability of the battery. As the market demands higher battery energy density and voltage, high-capacity and high-energy-density battery designs are becoming increasingly common. However, this design trend also brings the risk of thermal abuse failure, especially when the battery encounters abnormally high temperatures during use or charging. In such cases, the thermal stability of the separator becomes a critical consideration.

[0006] Technical issues

[0007] Traditional lithium-ion battery separators, especially polyolefin-based separators, are susceptible to thermal shrinkage. This shrinkage disrupts the separator's original stable structure, leading to direct contact between the positive and negative electrodes and causing an internal short circuit. An internal short circuit can trigger thermal runaway, a dangerous state characterized by a rapid increase in internal battery temperature that can lead to combustion or explosion. Thermal runaway not only reduces battery lifespan but, more importantly, poses a serious safety hazard to the equipment and personnel using the battery.

[0008] As can be seen from the above, the separator of current batteries will shrink under high temperature environment, which can easily lead to thermal runaway of the battery.

[0009] Technical solutions

[0010] This application provides a battery and a battery pack to solve the problem that the separator of batteries in related technologies tends to shrink under high temperature conditions, which can easily lead to thermal runaway.

[0011] According to one aspect of this application, a battery is provided, the battery including a cell and a gel, the cell including an electrode and a separator, an electrode being disposed between two adjacent separators along the thickness direction of the cell, the separator having a first portion and a second portion along the height direction of the cell, the second portion being disposed at both ends of the first portion, the first portion being stacked with the electrode, the second portion protruding from both ends of the electrode, a plurality of second portions located at the same end of the electrode being disposed along the thickness direction of the cell toward the central region of the cell, the plurality of second portions being bonded by the gel to form an insulating structure disposed on the top and bottom surfaces of the electrode.

[0012] According to another aspect of this application, a battery pack is provided, which includes the battery described above.

[0013] Beneficial effects

[0014] The battery of this application adopts a second part of the separator extending out of the electrode to form an insulating structure set at the top and bottom ends of the electrode, so as to realize the structure of the separator covering the electrode. Multiple second parts are fixed by the colloid to form an integral insulating structure, which effectively avoids the situation that the separator cannot insulate the positive and negative electrodes due to shrinkage when thermal runaway occurs, thereby reducing the probability of thermal runaway and improving the safety of battery use.

[0015] The multiple second parts located at the same end of the electrode in this application are arranged in a mutually oriented manner, which facilitates the fixing of the multiple second parts by means of adhesive bonding, so that they are respectively set on the top and bottom surfaces of the electrode. The structure is simple, the operation is convenient, and it is beneficial to improve assembly efficiency.

[0016] Attached Figure Description

[0017] Figure 1 shows a front view of the electrode and colloid assembly of the battery cell of this application;

[0018] Figure 2 shows a top view of the battery cell of this application;

[0019] Figure 3 shows a bottom view of the battery cell of this application;

[0020] Figure 4 shows a schematic diagram of the structure of the electrode and separator arranged along the thickness direction of the battery cell in this application;

[0021] Figure 5 shows a schematic diagram of the battery of this application.

[0022] The above figures include the following reference numerals:

[0023] 10. Electrode; 110. Tab; 20. Colloid; 30. Diaphragm; 310. Second part; 320. First part; 330. Clearance channel; 340. Adhesive end; 40. Outer shell.

[0024] Embodiments of the present invention

[0025] In order to address the issue that thermal runaway risk increases due to thermal shrinkage of battery separators under high-temperature conditions in related technologies, this application provides a battery pack comprising multiple batteries.

[0026] The battery of this application has a structure in which the electrode sheets are covered by a separator. In high-temperature environments, the separator can remain insulating to prevent contact between the positive and negative electrodes of the battery, reduce the probability of thermal runaway, and improve battery life and safety. At the same time, the insulating effect of the separator can also improve the stability of battery use and enhance the user experience.

[0027] In this embodiment, the battery is a square pouch battery.

[0028] As shown in Figures 1 to 4, the battery includes a cell and a gel 20. The cell includes an electrode 10 and a separator 30. An electrode 10 is disposed between two adjacent separators 30 along the thickness direction of the cell. The separator 30 has a first part 320 and a second part 310 along the height direction of the cell. The second part 310 is disposed at both ends of the first part 320. The first part 320 is stacked with the electrode 10. The second part 310 protrudes from both ends of the electrode 10. Multiple second parts 310 located at the same end of the electrode 10 are disposed towards the center region of the cell along the thickness direction of the cell. Multiple second parts 310 are bonded together by the gel 20 to form an insulating structure disposed on the top and bottom surfaces of the electrode 10.

[0029] The electrode 10 includes a positive electrode and a negative electrode. A separator 30 is provided on both sides of the positive electrode and both sides of the negative electrode along the thickness direction of the battery cell. That is, a separator 30 is provided between the positive and negative electrode to insulate them. A separator 30 is provided at both ends along the stacking direction of the positive and negative electrode, so that after the second part 310 of the separator 30 is bonded, the electrode 10 is located inside the space formed by the separator 30, ensuring that both the bottom and top surfaces of the electrode 10 have insulating structures.

[0030] In this application, the first portion 320 of the separator 30 is stacked with the electrode 10 along the thickness direction of the cell to insulate the positive and negative electrodes in the thickness direction. The second portion 310 is disposed at both ends of the first portion 320 along the height direction of the cell and extends to the outside of the electrode 10. The second portion 310 is provided on both the top and bottom surfaces of the electrode 10. During battery assembly, because the separator 30 is flexible, the second portion 310 can be pressed to fit the top and bottom surfaces of the electrode 10. Since the separator 30 of this application can be adaptively deformed according to the installation space, Figure 4 shows the state in which it is not pressed.

[0031] In this embodiment, multiple second parts 310 are bonded and fixed by adhesive 20 and stacked along the thickness direction of the battery cell. Separators 30, positioned on both sides of the same electrode 10 along the thickness direction of the battery cell, cooperate to form a ring structure wound around the electrode 10. Compared to the sheet-like structure of the separator 30 in related technologies, the ring structure, positioned on the outer periphery of the electrode 10, provides constraint. Because it lacks free ends, it is less likely to experience thermal runaway due to thermal shrinkage of the separator 30 at high temperatures, leading to contact between the positive and negative electrodes.

[0032] In some embodiments, the battery of this application achieves the covering of the electrode 10 by extending the second portion 310 of the separator 30 out of the electrode 10 and bonding it in place, thereby forming an insulating structure on the top and bottom surfaces of the electrode 10. After the separator 30 is fixed by the colloid 20, it can effectively prevent the separator 30 from shrinking and failing to insulate the positive and negative electrodes in the event of thermal runaway, thereby reducing the probability of thermal runaway and improving the safety of battery use.

[0033] The diaphragm 30 of this application has a plurality of second parts 310 arranged in a mutually oriented manner, which facilitates the fixing of the plurality of second parts 310 by means of adhesive 20, so that they are respectively set on the top and bottom surfaces of the electrode 10. The structure is simple, the operation is convenient, and it is beneficial to improve the assembly efficiency.

[0034] In this embodiment, the height of the battery cell is in the Z direction as shown in Figure 1, the thickness direction of the battery cell is in the X direction as shown in Figure 2, and the length direction of the battery cell is in the Y direction as shown in Figure 2.

[0035] In this embodiment, the adhesive 20 is a UV adhesive. The adhesive 20 is used to bond multiple second parts 310 by dispensing. For example, a dispensing machine can be used to perform the dispensing operation so as to bond and fix multiple second parts 310 by dispensing technology.

[0036] In this embodiment, the colloid 20 is fixed by irradiation with an ultraviolet lamp or ultraviolet curing equipment. Compared with traditional encapsulation technologies, the setup in this application has low energy consumption and does not produce harmful gases, making it environmentally friendly. Furthermore, the technique of using UV-cured adhesive to fix the diaphragm 30 is simple and easy to implement, and provides excellent encapsulation results.

[0037] In this embodiment, the battery cell structure can be formed by winding the separator 30 and the electrode 10, that is, by winding the electrode 10 and the separator 30 using a battery cell winding fixture to form the battery cell; alternatively, the battery cell structure can be formed by stacking the separator 30 and the electrode 10, by sequentially stacking the electrode 10 and the separator 30 along the thickness direction to form the battery cell. The specific arrangement structure of the battery cell can be adaptively configured as needed.

[0038] In this embodiment, the surface of the separator 30 has an insulating coating to insulate the positive and negative electrodes, preventing them from conducting electricity through contact. The insulating coating can be provided on one side of the separator 30 or on both sides.

[0039] As shown in Figure 4, along the height direction of the battery cell, the second portions 310 at both ends of the first portion 320 are symmetrically arranged about the first portion 320.

[0040] The symmetrical arrangement of the second part 310 facilitates the formation of a symmetrical insulating structure on the top and bottom surfaces of the electrode 10, which helps to improve the overall insulation effect and enhance the safety of battery use.

[0041] In this embodiment, the insulation structure has a clearance channel 330, and the tab 110 of the electrode 10 passes through the clearance channel 330.

[0042] As shown in Figure 1, the clearance channel 330 provides clearance for the extension of the tab 110, so that the tab 110 can pass through the clearance channel 330 and be welded to the pole. The positive electrode has a positive tab and the negative electrode has a negative tab. There are two clearance channels 330, one of which is for the positive tab to pass through and the other is for the negative tab to pass through.

[0043] In this embodiment, multiple second portions 310 are provided, and the multiple second portions 310 form flush adhesive ends 340 in the adhesive area. The adhesive ends 340 of the multiple second portions 310 are stacked along the thickness direction of the battery cell.

[0044] In some embodiments, the adhesive ends 340 of this application are formed by shearing. That is, when the second portion 310 of the separator 30 is brought closer to the center along the thickness direction of the battery cell, the outer second portion 310 needs to be bent to a larger extent, and therefore its dimension in the height direction of the battery cell is longer than that of the inner second portion 310. Therefore, after bonding multiple second portions 310 to form a structure stacked along the thickness direction of the battery cell, the adhesive ends 340 of multiple second portions 310 are formed by cutting in the bonding area, and the adhesive ends 340 are parallel to the top and bottom surfaces of the battery cell.

[0045] As shown in Figure 5, in this embodiment, the battery also includes a casing 40, and the battery cell is disposed inside the casing 40. The casing 40 serves to protect and fix the battery cell. After the battery cell is placed inside the casing 40, an insulating structure is disposed between the bottom surface of the casing 40 and the electrode 10 to enhance the bottom insulation performance of the electrode 10 of the battery cell; the insulating structure is disposed between the bottom surface of the cover plate of the casing 40 and the electrode 10 to enhance the insulation performance of the top side of the electrode 10.

[0046] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0047] The battery of this application achieves the covering of the electrode 10 by extending the second part 310 of the separator 30 out of the electrode 10 and bonding it in place, thus forming an insulating structure on the top and bottom surfaces of the electrode 10. After the separator 30 is fixed by the colloid 20, it can effectively prevent the separator 30 from shrinking and failing to insulate the positive and negative electrodes in the event of thermal runaway, thereby reducing the probability of thermal runaway and improving the safety of battery use.

[0048] The diaphragm 30 of this application has multiple second parts 310 located at the same end of the electrode 10, which are arranged in a mutually oriented manner. This facilitates the fixing of the multiple second parts 310 by means of adhesive 20, so that they are respectively set on the top and bottom surfaces of the electrode 10. The structure is simple, the operation is convenient, and it is beneficial to improve the assembly efficiency.

Claims

1. A battery, comprising: a cell including a tab (10) and a separator (30), the tab (10) being arranged between two adjacent separators (30) along a thickness direction of the cell, the separator (30) having a first portion (320) and a second portion (310) along a height direction of the cell, the second portion (310) being arranged at both ends of the first portion (320), the first portion (320) being overlapped with the tab (10), and the second portion (310) protruding from both ends of the tab (10); a glue (20) arranged between a plurality of the second portions (310) at a same end of the tab (10) along the thickness direction of the cell towards a center region of the cell, the plurality of the second portions (310) being bonded by the glue (20) to form an insulation structure arranged on a top surface and a bottom surface of the tab (10).

2. The battery of claim 1, wherein, The second portions (310) at both ends of the first portion (320) along the height direction of the cell are symmetrically arranged with respect to the first portion (320).

3. The battery of claim 1, wherein, The insulation structure has a bypass channel (330) for a tab lug (110) of the tab (10) to pass through.

4. The battery of claim 1, wherein, The second portions (310) are arranged in plurality, and the plurality of the second portions (310) form flush bonding ends (340) at a bonding region, and the bonding ends (340) of the plurality of the second portions (310) are overlapped along the thickness direction of the cell.

5. The battery according to claim 1, wherein: the tab (10) includes a positive tab and a negative tab, and both sides of the positive tab and both sides of the negative tab are arranged with the separator (30) along the thickness direction of the cell.

6. The battery of any one of claims 1-5, wherein, the battery is a square battery, the cell is formed by winding the separator (30) and the tab (10); or the cell is formed by stacking the separator (30) and the tab (10).

7. The battery according to any one of claims 1 to 5, wherein: the separator (30) is arranged with an insulation coating on one side; or the separator (30) is arranged with an insulation coating on both sides.

8. The battery according to any one of claims 1 to 5, further comprising at least one of: the glue (20) is UV glue; the glue (20) bonds the second portions (310) by dispensing.

9. The battery according to any one of claims 1 to 5, further comprising a housing (40), the cell being arranged inside the housing (40), the insulation structure is arranged between a bottom surface of the housing (40) and the tab (10); and the insulation structure is arranged between a bottom surface of a cover plate of the housing (40) and the tab (10).

10. A battery pack, comprising the battery according to any one of claims 1 to 9.

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