Battery and battery pack

Abstract

The application relates to the technical field of batteries, and particularly discloses a battery and a battery pack, wherein the battery comprises a shell, a battery cell, a cover plate and a protective patch. The shell is provided with an opening, the battery cell is arranged in the shell, the cover plate covers and seals the opening and is provided with an explosion-proof valve; the protective patch is arranged on the side of the cover plate away from the battery cell and covers at least the peripheral area of the explosion-proof valve; the melting point of the protective patch is >200 DEG C; the protective patch further comprises a glue sticking area which is pasted to the cover plate, and the area ratio of the glue sticking area to the area of the region surrounded by the explosion-proof valve is 3% to 50%. In the application, the protective patch covers the peripheral area of the explosion-proof valve, the melting point of the protective patch is higher than the temperature of the high-temperature eruption material, that is, a physical barrier is formed by using a high-temperature resistant material, direct contact of the eruption material with the explosion-proof valve is prevented, the explosion-proof valve is prevented from being softened, deformed or melted through by the eruption material, and the normal pressure relief function of the explosion-proof valve is ensured.

Description

Technical Field

[0001] This application relates to the field of battery technology and specifically discloses a battery and a battery pack. Background Technology

[0002] Currently, battery packs are generally integrated from multiple compactly arranged individual cells through series and parallel connections to achieve high energy density and lightweight design.

[0003] During battery pack use, if a single cell experiences thermal runaway due to internal short circuits, mechanical damage, or other reasons, its internal temperature can rapidly rise to hundreds or even thousands of degrees Celsius, ejecting high-temperature substances that can affect adjacent cells. Specifically, under these extreme high-temperature conditions, the insulating patches on the outer side of adjacent battery covers can melt rapidly, potentially causing the explosion-proof valves on the covers to come into direct contact with the ejected high-temperature substances. These substances may cause the explosion-proof valves to soften and deform locally, or even melt through, affecting the integrity and safety of the battery. Utility Model Content

[0004] The purpose of this application is to solve at least some of the technical problems mentioned above, and this purpose is achieved through the following technical solutions: In a first aspect, this application provides a battery comprising a casing, a battery cell, a cover plate, and a protective patch. The casing has an opening, the battery cell is disposed inside the casing, the cover plate seals the opening and is provided with an explosion-proof valve; the protective patch is disposed on the side of the cover plate facing away from the battery cell and at least covers the periphery of the explosion-proof valve; the melting point of the protective patch is >200°C; the protective patch also includes an adhesive area, which is adhered to the cover plate, and the ratio of the area of ​​the adhesive area to the area enclosed by the explosion-proof valve is 3% to 50%.

[0005] Secondly, this application also provides a battery pack, including the battery of the first aspect.

[0006] The technical solution proposed in this application has at least the following technical effects: In this application, the protective patch covers the periphery of the explosion-proof valve. Its melting point is higher than that of the high-temperature ejected material. In other words, a physical barrier is formed by the high-temperature resistant material to prevent the ejected material from directly contacting the explosion-proof valve, thereby avoiding the ejected material from causing the explosion-proof valve to soften, deform or melt through, and ensuring the normal pressure relief function of the explosion-proof valve. Attached Figure Description

[0007] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0008] Figure 1 This is a schematic diagram of the battery structure described in an embodiment of this application; Figure 2 This is a schematic diagram of the battery cell structure described in the embodiments of this application; Figure 3 This is a cross-sectional schematic diagram of the cover plate described in an embodiment of this application; Figure 4 for Figure 3 Enlarged view of point A in the middle; Figure 5 This is a partial cross-sectional schematic diagram of the protective patch described in the embodiments of this application.

[0009] Explanation of reference numerals in the attached figures: 10. Housing; 20. Battery cell; 30. Cover plate; 301. Explosion-proof valve; 302. Protrusion; 303. Explosion-proof sheet; 40. Protective patch; 401. Adhesive area; 402. Reinforcing layer; 403. Support layer. Detailed Implementation

[0010] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0011] The embodiments of this application are described below with reference to the accompanying drawings. It can be understood that the technical features involved in the different embodiments described below can be combined with each other as long as they do not conflict with each other.

[0012] Firstly, referring to Figures 1 to 5 This application provides an embodiment of a battery comprising a housing 10, a battery cell 20, a cover plate 30, and a protective patch 40. The housing 10 has an opening, the battery cell 20 is disposed inside the housing 10, the cover plate 30 seals the opening and is provided with an explosion-proof valve 301; the protective patch 40 is disposed on the side of the cover plate 30 facing away from the battery cell 20, and at least covers the periphery of the explosion-proof valve 301; the melting point of the protective patch 40 is >200°C; the protective patch 40 also includes an adhesive area 401, which is adhered to the cover plate 30, and the ratio of the area of ​​the adhesive area 401 to the area enclosed by the explosion-proof valve 301 is 3% to 50%.

[0013] In this embodiment, the protective patch 40 covers the periphery of the explosion-proof valve 301. Its melting point is higher than that of the high-temperature ejected material. In other words, a physical barrier is formed by the high-temperature resistant material to prevent the ejected material from directly contacting the explosion-proof valve 301, thus avoiding the ejected material from causing the explosion-proof valve 301 to soften, deform or melt through, and ensuring the normal pressure relief function of the explosion-proof valve 301.

[0014] In some embodiments, the shear strength of the adhesive region 401 is >0.5 MPa.

[0015] In this embodiment, the adhesive area 401 ensures that the protective patch 40 remains firmly attached under extreme temperatures and vibrations, preventing it from falling off due to thermal expansion or mechanical stress and maintaining the stability of the protection.

[0016] In some embodiments, the adhesive area 401 is continuously distributed.

[0017] In this embodiment, one implementation of the adhesive region 401 is proposed. The adhesive region 401 is continuously distributed to enhance the bonding strength of the overall structure.

[0018] In some embodiments, the adhesive areas 401 are discontinuously distributed, with an interval of 0.5mm-5mm.

[0019] In this embodiment, another implementation of the adhesive area 401 is proposed. The adhesive area 401 is discontinuously distributed, retaining local air permeability, balancing the bonding strength and explosion-proof requirements, and avoiding the accumulation of internal pressure.

[0020] In some embodiments, refer to Figure 4 A protrusion 302 is provided around the explosion-proof valve 301 on the cover plate 30, and a protective patch 40 is provided on the protrusion 302.

[0021] In this embodiment, the protrusion 302 structure forms a mechanical limit, enhances the fit between the patch and the cover plate 30, and prevents displacement; at the same time, it improves the protection of the edge of the explosion-proof valve 301, reduces the penetration path of high-temperature ejected materials generated by other batteries to the explosion-proof valve 301; moreover, the protrusion 302 can increase the structural strength and optimize the structural stability.

[0022] In some embodiments, the width of the adhesive area 401 is greater than the width of the upper surface of the protrusion 302.

[0023] In this embodiment, the adhesive area 401 covers the edge of the protrusion 302 to form a redundant seal, preventing high-temperature gas generated by other batteries from penetrating through the gap between the protective patch 40 and the protrusion 302, thereby improving the reliability of protection.

[0024] The width of the adhesive area 401 is 0.6mm-2.1mm; the width of the upper surface of the protrusion 302 is 0.5mm-2mm.

[0025] In some embodiments, a notch is provided on the protrusion 302, and the width of the notch is 0.5mm-1mm.

[0026] In this embodiment, the notch serves as a pressure relief channel, allowing a small amount of gas to be released slowly before the explosion-proof valve 301 is triggered, thus mitigating the sudden increase in internal pressure and preventing a sudden explosion. The width of the notch needs to balance air permeability and protective performance.

[0027] In some embodiments, the edge of the explosion-proof valve 301 has a racetrack-shaped structure, and the notch is provided on the arc edge and / or straight edge of the racetrack-shaped structure.

[0028] In this embodiment, the runway-shaped edge can disperse stress and reduce local stress concentration; the notch position optimizes the gas flow direction, guides the ejected material to be discharged along a preset path, and reduces the impact on surrounding components.

[0029] In some embodiments, refer to Figure 4 The explosion-proof valve 301 includes an explosion-proof disc 303, and the distance between the explosion-proof disc 303 and the protective patch 40 is 0.5mm-5mm.

[0030] In this embodiment, the spacing design prevents the protective patch 40 from obstructing the rapid pressure release of the explosion-proof valve 301, while reducing the conduction of high temperature to the explosion-proof sheet 303 and preventing the explosion-proof sheet 303 from being affected by the high temperature generated by other batteries.

[0031] In some embodiments, the adhesive area 401 is made of one or more of epoxy resin, polyurethane, acrylate or silicone.

[0032] In some embodiments, the cover plate 30 is provided with an explosion-proof valve 301 hole, the periphery of the explosion-proof valve 301 is welded to the explosion-proof valve 301 hole to form a weld, and the protective patch 40 at least covers the weld.

[0033] In this embodiment, the weld is the weak point connecting the explosion-proof valve 301 and the cover plate 30. The protective patch 40 covers the weld, enhances the structural strength of the welded area, and can prevent high-temperature ejected materials (such as molten metal and gas) from corroding the weld, thus avoiding weld cracking that could lead to sealing failure of the explosion-proof valve 301.

[0034] In some embodiments, refer to Figure 4 The protective patch 40 covers the entire explosion-proof valve 301.

[0035] In this embodiment, the protective patch 40 provides comprehensive protection for the explosion-proof valve 301, further preventing high-temperature ejected materials from affecting the performance of the explosion-proof valve 301.

[0036] It should be noted that the protective patch 40 can be scored to avoid affecting the normal use of the explosion-proof valve 301.

[0037] In some embodiments, refer to Figure 5 The protective patch 40 includes a reinforcing layer 402 and a supporting layer 403. The reinforcing layer 402 is embedded inside the supporting layer 403, and the adhesive area 401 is located on the supporting layer 403.

[0038] In this embodiment, a layered design is used to resist the high temperature of the ejected material and provide structural strength, thereby maintaining the morphological stability of the protective patch 40.

[0039] In some embodiments, the melting point of the reinforcing layer 402 is between 150°C and 2050°C.

[0040] In particular, in thermogravimetric analysis (TGA), the material of reinforcing layer 402 satisfies the 5% mass loss temperature (T5%) > 200℃, which means that the material has good thermal stability in high-temperature environments and its decomposition or melting initiation temperature is relatively high.

[0041] In some embodiments, the reinforcing layer 402 comprises one or more of glass fiber, carbon fiber, polymer fiber or inorganic fiber, and / or the supporting layer 403 comprises a resin structure.

[0042] Specifically, the resin structures mentioned above can be polypropylene resin, epoxy resin, polycarbonate resin, polyurethane resin, or phenolic resin, which have no melting point and are usually carbonized at high temperatures.

[0043] In some embodiments, the protective patch 40 may also be a high-temperature resistant glass structure and / or ceramic structure.

[0044] Secondly, this application proposes a battery pack that includes the battery of the first aspect.

[0045] Understandably, the battery pack of the second aspect has all the technical effects of the battery of the first aspect, and its specific technical effects will not be elaborated here.

[0046] It should be noted that the battery in the first aspect and the battery pack in the second aspect also include other components, which will not be described in detail here.

[0047] In particular, the term "and / or" in this application should be understood as follows: In the first case, the term “and / or” between the first subject and the second subject includes any of the following meanings: (1) only the first subject; (2) only the second subject; and (3) both the first subject and the second subject.

[0048] In the second case, the term "and / or" between the last two of three or more subjects means including at least one of the subjects. For example, "first subject, second subject and / or third subject" has the same meaning as "first subject and / or second subject and / or third subject", specifically including the following combinations: (1) only the first subject; (2) only the second subject; (3) only the third subject; (4) first subject and second subject and no third subject; (5) first subject and third subject and no second subject; (6) second subject and third subject and no first subject; and (7) first subject, second subject and third subject; Furthermore, the character " / " in this application indicates that the objects before and after it are in an "or" relationship.

[0049] Although embodiments of this application have been 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 this application, and such modifications and variations all fall within the scope defined by this application.

Claims

1. A battery, characterized in that, include: The housing (10) has an opening; The battery cell (20) is disposed inside the housing (10); Cover plate (30) covers the opening and is equipped with explosion-proof valve (301). A protective patch (40) is disposed on the side of the cover plate (30) facing away from the battery cell (20) and covers at least the periphery of the explosion-proof valve (301); the melting point of the protective patch (40) is >200°C; the protective patch (40) also includes an adhesive area (401), which is adhered to the cover plate (30), and the ratio of the area of ​​the adhesive area (401) to the area of ​​the region enclosed by the explosion-proof valve (301) is 3% to 50%.

2. The battery according to claim 1, characterized in that, The shear strength of the adhesive region (401) is >0.5MPa.

3. The battery according to claim 1, characterized in that, The adhesive area (401) is continuously distributed.

4. The battery according to claim 1, characterized in that, The adhesive areas (401) are discontinuously distributed, with an interval of 0.5mm-5mm.

5. The battery according to claim 1, characterized in that, The cover plate (30) has a protrusion (302) arranged around the explosion-proof valve (301), and the protective patch (40) is arranged on the protrusion (302).

6. The battery according to claim 5, characterized in that, The width of the adhesive area (401) is greater than the width of the upper surface of the protrusion (302).

7. The battery according to claim 5, characterized in that, The protrusion (302) has a notch with a width of 0.5mm-1mm.

8. The battery according to claim 7, characterized in that, The edge of the explosion-proof valve (301) has a racetrack-shaped structure, and the notch is provided on the arc edge and / or straight edge of the racetrack-shaped structure.

9. The battery according to claim 1, characterized in that, The explosion-proof valve (301) includes an explosion-proof disc (303), and the distance between the explosion-proof disc (303) and the protective patch (40) is 0.5mm-5mm.

10. The battery according to claim 1, characterized in that, The adhesive area (401) is made of one or more of epoxy resin, polyurethane, acrylate or silicone.

11. The battery according to claim 1, characterized in that, The cover plate (30) is provided with an explosion-proof valve (301) hole. The periphery of the explosion-proof valve (301) is welded to the explosion-proof valve (301) hole to form a weld. The protective patch (40) at least covers the weld.

12. The battery according to claim 1, characterized in that, The protective patch (40) covers the entire explosion-proof valve (301).

13. The battery according to claim 1, characterized in that, The protective patch (40) includes a reinforcing layer (402) and a supporting layer (403). The reinforcing layer (402) is embedded inside the supporting layer (403), and the adhesive area (401) is located on the supporting layer (403).

14. The battery according to claim 13, characterized in that, The melting point of the reinforcing layer (402) is 150°C to 2050°C.

15. The battery according to claim 13, characterized in that, The reinforcing layer (402) includes one or more of glass fiber, carbon fiber, polymer fiber or inorganic fiber, and / or the supporting layer (403) includes a resin structure.

16. A battery pack, characterized in that, Includes the battery as described in any one of claims 1 to 15.

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