Single battery and battery pack

Abstract

The utility model relates to the technical field of batteries, in particular to a single battery and a battery pack, and the single battery comprises a battery cell, a cover plate, an anti-explosion valve, an anti-explosion part and a shell, the cover plate is arranged at one end, in the first direction, of the shell, and the battery cell is arranged in a cavity defined by the cover plate and the shell in a matched mode; the cover plate is provided with an explosion-proof hole; the anti-explosion valve is connected with the cover plate and covers the anti-explosion hole; the explosion-proof part is arranged on one side, deviating from the battery cell, of the cover plate, the explosion-proof part comprises a convex hull part and a connecting part connected with the convex hull part, the convex hull part is opposite to the explosion-proof valve, the convex hull part protrudes towards the direction deviating from the explosion-proof valve, the convex hull part is provided with a groove, a notch of the groove faces the cover plate, the explosion-proof valve is located in an orthographic projection of the notch on the cover plate, and the connecting part is connected with the cover plate. By arranging the anti-explosion piece, the anti-explosion valve can be protected in the process of manufacturing the single battery and assembling the single battery into the battery pack, so that the quality of the anti-explosion valve is effectively guaranteed, and the safety of the single battery is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a single cell and a battery pack. Background Art

[0002] Monocells are generally equipped with explosion-proof valves. The purpose is that when thermal runaway occurs in the monocell, the explosion-proof valve can crack to discharge the pressure in the monocell to avoid more serious explosions and other dangers. Monocells are generally assembled into battery packs when used. There are many links in the process from monocell manufacturing to assembly into battery packs. For example, monocells need to go through cover welding, liquid injection, edge voltage (i.e., the voltage between the pole and the shell), and internal resistance measurement, and then they are assembled into battery packs after capacity screening. These links will affect the durability of the explosion-proof valve, resulting in a decline in the quality of the explosion-proof valve, thereby shortening the service life of the explosion-proof valve, which will lead to the premature end of the life of the explosion-proof valve, causing the explosion-proof valve to open before reaching the design value. Utility Model Content

[0003] The present application provides a single cell and a battery pack to solve the technical problem of short life of explosion-proof valves.

[0004] In one aspect, the present application provides a single cell battery, the single cell battery having a first direction, the single cell battery comprising a battery cell, a cover plate, an explosion-proof valve, an explosion-proof component and a shell;

[0005] The cover plate is arranged at one end of the shell in the first direction, and the cover plate cooperates with the shell to enclose a cavity, and the battery cell is arranged in the cavity; the cover plate is provided with an explosion-proof hole;

[0006] The explosion-proof valve is connected to the cover plate and covers the explosion-proof hole;

[0007] The explosion-proof component is arranged on the side of the cover plate away from the battery cell, and the explosion-proof component includes a convex portion and a connecting portion connected to the convex portion. The convex portion is arranged opposite to the explosion-proof valve, and the convex portion protrudes in a direction away from the explosion-proof valve. The convex portion has a groove, and the notch of the groove faces the cover plate, and the explosion-proof valve is arranged opposite to the notch; the connecting portion is connected to the cover plate.

[0008] As one of the optional embodiments of the present solution, the convex portion includes a top wall and a circumferential wall, the top wall is spaced apart from the cover plate, one end of the circumferential wall is connected to the top wall, and the other end is connected to the connecting portion.

[0009] As one of the optional embodiments of the present solution, the connecting portion is connected to an end of the circumferential wall away from the top wall, and the distance between the connecting portion and the axis of the convex portion gradually increases along the direction from the top wall to the cover plate.

[0010] As one of the optional embodiments of this solution, the thickness of the top wall is smaller than the thickness of the circumferential wall.

[0011] As one of the optional embodiments of this solution, the distance between the top wall and the explosion-proof valve is greater than the thickness of the top wall;

[0012] The convex portion further includes a connecting wall, and the connecting wall is respectively connected to the top wall and the circumferential wall; the top wall and the circumferential wall are arranged at an angle, and the included angle α between the top wall and the circumferential wall satisfies: 60° ≤ α ≤ 120°.

[0013] As one of the optional embodiments of this solution, the bursting pressure value of the convex portion is less than the bursting pressure value of the explosion-proof valve;

[0014] And / or, the explosion-proof member is detachably connected to the cover plate.

[0015] As one of the optional embodiments of this solution, the convex portion is provided with one or more through holes, and the through holes are respectively communicated with the groove and the outside of the convex portion.

[0016] As one of the optional embodiments of this solution, the area enclosed by the orthographic projection of each through hole on the plane where the extension trend of the explosion-proof valve is located is S1 mm 2 , satisfying: 0.0079mm 2 ≤ S1 ≤ 19.6mm 2 ; the total area of all through holes is S2mm 2 , satisfying: 0.0079mm 2 < S2 ≤ 58.9mm 2 .

[0017] As one of the optional embodiments of this solution, the single cell further includes a pole column, the pole column penetrates through the cover plate, and one end extends into the cavity and is connected to the battery cell, and the other end exposes on the surface of the cover plate facing away from the cavity;

[0018] In the first direction, the size of the explosion-proof member is L1 mm, and the distance from the end face of the pole column exposed on the cover plate to the surface on the side facing the explosion-proof member is L2 mm, L1 ≤ L2.

[0019] On the other hand, the present application also provides a battery pack, including the single cell as described in any one of the above.

[0020] One of the above technical solutions has the following advantages or beneficial effects:

[0021] For the single cell of the present application, by arranging an explosion-proof member around the explosion-proof valve, the explosion-proof valve can be protected during the manufacturing process of the single cell and the assembly into a battery pack, effectively ensuring the quality of the explosion-proof valve, thereby effectively improving the service life of the explosion-proof valve and enhancing the safety of the single cell; the explosion-proof member adopts a convex structure design, has good strength, and can form good protection for the explosion-proof valve.

[0022] The battery pack of the present application may include all the technical features and beneficial effects of the above single battery, which will not be elaborated herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The technical solutions and other beneficial effects of the present application will become obvious by describing the specific embodiments of the present application in detail with reference to the accompanying drawings.

[0024] Figure 1 FIG. 9 is a front view structural schematic diagram of a single battery provided by an embodiment of the present application;

[0025] Figure 2 FIG. 13 is a top view structural schematic diagram of a single battery provided by an embodiment of the present application;

[0026] Figure 3 is Figure 2 a sectional view structural schematic diagram of the structure shown in FIG. 19 at position A;

[0027] Figure 4 is Figure 3 an enlarged schematic diagram of the structure shown in FIG. 25 at position I;

[0028] Figure 5 FIG. 29 is a top view structural schematic diagram of an explosion-proof member provided by an embodiment of the present application;

[0029] Figure 6 is Figure 5 a sectional view structural schematic diagram of the structure shown in FIG. 35 at position B;

[0030] Figure 7 is Figure 5 a sectional view structural schematic diagram of the structure shown in FIG. 41 at position C;

[0031] Figure 8 FIG. 45 is a top view structural schematic diagram of an explosion-proof member provided by another embodiment of the present application;

[0032] Figure 9 FIG. 49 is a front view structural schematic diagram of a single battery provided by another embodiment of the present application;

[0033] Figure 10 FIG. 53 is a graph of the bursting pressure values of the explosion-proof valves during the aging prediction simulation after the single batteries with and without the explosion-proof members provided by the present application are assembled into a battery pack.

[0034] Reference Numerals:

[0035] 1, battery cell; 2, cover plate; 21, explosion-proof hole; 3, explosion-proof valve; 4, explosion-proof member; 41, convex portion; 411, groove; 412, top wall; 413, circumferential wall; 414, axis; 415, through hole; 416, connecting wall; 42, connecting portion; 5, terminal; 6, housing; 61, cavity; 7, protective film; Z, first direction; X, second direction. Detailed implementation manners

[0036] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present application.

[0037] In the description of the present application, it should be noted that, unless otherwise clearly defined and limited, the term "and / or" in this article is only an association relationship describing associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the associated objects before and after without special instructions.

[0038] The present application provides a single battery. By arranging an explosion-proof member 4 around the explosion-proof valve 3, the explosion-proof valve 3 can be protected during the manufacturing process of the single battery and the assembly into a battery pack. It can be understood that the single battery in the present application is a square battery. In other embodiments, the explosion-proof member 4 can also be arranged on a cylindrical battery cell or other battery cells, which is not limited herein. The single battery and the battery pack provided by the present application will be described below.

[0039] For a clearer description of the technical solution, define the first direction Z, the second direction X, and the third direction Y intersecting as shown in Figure 1 Preferably, the first direction Z, the second direction X, and the third direction Y intersect, such as being perpendicular to each other. It can be understood that the first direction Z, the second direction X, and the third direction Y are not absolutely perpendicular, and an included angle also belongs to the category of being perpendicular to each other, such as the included angle between two intersecting directions being between 85° and 95°.

[0040] Please refer to Figures 1 to 5, the single cell includes a battery cell 1, a cover plate 2, an explosion-proof valve 3, an explosion-proof component 4 and a housing 6. Among them, the cover plate 2 is arranged at one end of the housing 6 in the first direction Z. The battery cell 1 is arranged in a cavity 61 formed by the cooperation of the cover plate 2 and the housing 6. An explosion-proof hole 21 is opened on the cover plate 2. The explosion-proof hole 21 penetrates the cover plate 2 along the first direction Z. The explosion-proof valve 3 is connected to the cover plate 2 and covers the explosion-proof hole 21. The explosion-proof component 4 is arranged on the side of the cover plate 2 facing away from the battery cell 1. The explosion-proof component 4 includes a convex part 41 and a connecting part 42 connected to the convex part 41. The convex part 41 is arranged opposite to the explosion-proof valve 3. The convex part 41 protrudes in a direction away from the explosion-proof valve 3. The convex part 41 has a groove 411. The notch of the groove 411 faces the cover plate 2. The explosion-proof valve 3 is arranged opposite to the notch. The connecting part 42 is connected to the cover plate 2.

[0041] By arranging the explosion-proof component 4 around the explosion-proof valve 3, the explosion-proof valve 3 can be protected during the manufacturing process of the single cell and the assembly into a battery pack, preventing the explosion-proof valve 3 from being damaged, thus effectively ensuring the quality of the explosion-proof valve 3 and improving the safety of the single cell. The explosion-proof component 4 adopts a convex structure design and has good strength, which can form good protection for the explosion-proof valve 3. In addition, since the explosion-proof valve 3 is arranged opposite to the notch of the convex part 41, that is, from the perspective along the first direction Z, at least a part of the orthographic projection of the explosion-proof valve 3 on the cover plate 2 coincides with the orthographic projection of the notch on the cover plate 2. When the explosion-proof valve 3 bursts and substances such as gas and particulate matter in the battery cell 1 are ejected, it can ensure the direction along the axis of the convex part 41, thus minimizing the problem of the gas, particulate matter, etc. in the battery cell 1 spraying around, reducing the spraying range of the gas, particulate matter, etc., and reducing the impact on the surrounding area when the single cell is in thermal runaway.

[0042] Further, please continue to refer to Figures 1 to 5 , in this embodiment, the convex part 41 includes a top wall 412 and a circumferential wall 413. The top wall 412 is arranged at an interval from the cover plate 2. One end of the circumferential wall 413 is connected to the top wall 412, and the other end is connected to the connecting part 42. The connecting part 42 and the circumferential wall 413 are separated by the dotted line in Figure 4 . For a clearer description of the solution of this application, the dotted line is only for illustration and does not limit the protection scope of this application. It can be understood that in other embodiments, the convex part 41 can be hemispherical or other irregular shapes, which are not limited here.

[0043] In some embodiments, the connecting part 42 is connected to the end of the circumferential wall 413 facing away from the top wall 412, and along the direction from the top wall 412 to the cover plate 2, the distance between the connecting part 42 and the axis 414 of the convex part 41 gradually increases. Since the distance between the connecting part 42 and the convex part 41 gradually increases, it can ensure a good supporting effect on the convex part 41, enhance the structural strength of the convex part 41, and further form good protection for the explosion-proof valve 3.

[0044] For further information, see Figures 4 to 6 In this embodiment, the thickness of the top wall 412 of the convex portion 41 is less than the thickness of the circumferential wall 413. On the one hand, since the thickness of the circumferential wall 413 is greater than the thickness of the top wall 412, it can play a good supporting effect, which helps to ensure the structural strength of the explosion-proof component 4 and try to avoid the explosion-proof component 4 from deforming during the assembly process of the single battery; on the other hand, since the thickness of the top wall 412 is less than the thickness of the circumferential wall 413, when the battery cell 1 has thermal runaway, the internal pressure of the single battery exceeds the safety limit, the explosion-proof valve 3 opens, and gas, particles and other substances are ejected from the explosion-proof hole 21. Due to the restriction of the explosion-proof component 4, the ejection speed of gas and other substances is effectively reduced, and the ejected particles are effectively prevented from diffusing in four directions and possibly falling on the positive pole and the negative pole to cause a short circuit and further aggravate the thermal runaway; when the gas and particles break through the top wall of the convex portion 41, the speed of the gas and particles is further reduced, which is also conducive to effectively avoiding falling on the positive pole and the negative pole, which may further aggravate the thermal runaway.

[0045] In some embodiments, the distance between the top wall 412 and the explosion-proof valve 3 is greater than the thickness of the top wall 412. Specifically, the distance between the top wall 412 and the explosion-proof valve 3 is 1 to 10 mm. In other embodiments, the distance between the top wall 412 and the explosion-proof valve 3 can be set according to the thickness of the top wall 412, which is not limited here.

[0046] In some embodiments, the convex portion 41 further includes a connecting wall 416, which is arc-shaped and connected to the top wall 412 and the circumferential wall 413, respectively. The connecting wall 416 forms an arc transition between the top wall 412 and the circumferential wall 413, effectively preventing the top wall 412 and the circumferential wall 413 from being too sharp at the mutually connected part. The distance between the top wall 412 of the convex portion 41 and the explosion-proof valve 3 is greater than the thickness of the top wall 412, the side of the connecting wall 416 close to the cover plate 2 is connected to the circumferential wall 413, and the side of the connecting wall 416 away from the cover plate 2 is connected to the top wall 412, and the top wall 412, the connecting wall 416 and the circumferential wall 413 are integrally formed. The top wall 412 and the circumferential wall 413 are arranged at an angle, and the angle α between the top wall 412 and the circumferential wall 413 satisfies: 60°≤α≤120°, that is, the angle between the circumferential wall 413 along the extension direction of the cover plate 2 to the top wall 412 and the extension direction of the top wall 412 is α. To be precise, α is the angle between the explosion-proof valve and the circumferential wall 413. Figure 2After being sectioned at the A-A position, the included angle between the cross-section of the top wall 412 and the cross-section of the circumferential wall 413. When the included angle between the top wall 412 and the circumferential side wall 413 is between 60° and 120°, during the installation or transportation of the single cell, if the explosion-proof member 4 is subjected to an external force, when the top wall 412 undergoes an inward concave deformation, the amount of depression will not exceed the thickness of the top wall 412. Thus, the structural strength of the explosion-proof member 4 can be ensured. Even if the top wall 412 undergoes a concave deformation, the top wall 412 will not contact the explosion-proof valve 3, ensuring a good protection effect of the explosion-proof member 4 on the explosion-proof valve 3.

[0047] Furthermore, the bursting pressure value of the convex portion 41 is less than the bursting pressure value of the explosion-proof valve 3. Specifically, in this embodiment, the preset bursting pressure value of the explosion-proof valve 3 is 0.5 - 1.3 MPa, and the preset bursting pressure value of the external explosion-proof valve 33 is 0.2 - 0.6 MPa. It can be understood that the preset bursting pressure value of the explosion-proof valve 3 has a standard deviation of ±0.1 - 0.3 MPa. The convex portion 41 mainly plays a role in protecting the explosion-proof valve 3 and does not need to be set with too high a bursting pressure value. By setting the bursting pressure value of the external explosion-proof valve 3 to be less than that of the convex portion 41, the production cost of the explosion-proof member 4 can be reduced.

[0048] Specifically, the setting of the bursting pressure values of the convex portion 41 and the explosion-proof valve 3 needs to be determined according to the specific type of single cell and the usage scenario. Generally, factors such as the maximum charging and discharging pressures of the single cell, as well as temperature rise and current, need to be considered. The selection of the bursting pressure value also needs to consider the manufacturing process and material characteristics of the explosion-proof valve 3 to ensure that the explosion-proof valve 3 can reliably open within a certain range and release internal gases, particulate matters, etc., and ensure that the explosion-proof valve 3 itself will not fail or be damaged due to the selection of the bursting pressure value. Generally speaking, the bursting pressure value of the explosion-proof valve 3 is not greater than 0.6 MPa. According to the bursting pressure value of the explosion-proof valve 3, the material and manufacturing process of the explosion-proof member 4 are selected to ensure that the bursting pressure value of the explosion-proof member 4 is within the range of 0.2 - 0.6 MPa.

[0049] In some embodiments, refer to Figures 5 to 8, a through hole 415 is formed in the convex hull portion 41. The through hole 415 is respectively communicated with the groove 411 and the outside of the convex hull portion 41, that is, the through hole 415 penetrates the top wall 412 along the axis 414 direction of the convex hull portion 41. In this embodiment, a plurality of through holes 415 are provided. In other embodiments, the number of through holes 415 can also be one or two, which is not limited herein. By providing the through hole 415, when the aperture of the through hole 415 is small and the battery cell 1 is in thermal runaway, the explosion-proof valve 3 opens, and some substances such as gas and particulate matter are discharged from the aperture of the through hole 415. Some substances such as gas and particulate matter break through the top wall of the convex hull portion 41, and the convex hull portion 41 explodes, and the gas is ejected from the convex hull portion 41. Under the limiting action of the explosion-proof member 4, the ejection speed of substances such as gas is effectively reduced, and it is effectively avoided that the ejected particulate matter and other substances diffuse in all directions and may fall on the positive electrode post and the negative electrode post to cause a short circuit, resulting in further aggravation of thermal runaway; when the aperture of the through hole 415 is large and the battery cell 1 is in thermal runaway, the explosion-proof valve 3 opens, and substances such as gas and particles can be discharged through the through hole 415, and the convex hull portion 41 does not explode. Similarly, under the limiting action of the explosion-proof member 4, the ejection speed of substances such as gas is effectively reduced, and it is effectively avoided that the ejected particulate matter and other substances diffuse in all directions and may fall on the positive electrode post and the negative electrode post to cause a short circuit, resulting in further aggravation of thermal runaway.

[0050] Specifically, in this embodiment, the total area of all through holes 415 is S2 mm 2 , S2 satisfies: 0.0079mm 2 < S2 ≤ 58.9mm 2 . In other embodiments, the aperture sizes of each through hole 415 can be different, and the through hole 415 can also be set to other shapes, such as oval, triangular, rectangular, etc., which is not limited herein.

[0051] In some embodiments, taking each through hole 415 as a round hole with the same aperture size as an example, the aperture of each through hole 415 is D mm, which satisfies: 0.1mm ≤ D ≤ 5mm. The area enclosed by the orthographic projection of each through hole 415 on the plane where the extension trend of the explosion-proof valve 3 is located is S1 mm 2 , which satisfies: 0.0079mm 2 ≤ S1 ≤ 19.6mm 2 ; the total area S2 of all through holes 415 = 1 / 4nπD2, where n is the number of through holes 415. That is to say, the number of through holes 415 can be 3, and the diameter of the through hole 415 is 5mm. At this time, the total area of all through holes 415 is the largest, which is 58.9mm 2It should be noted that the plane where the extension trend of the explosion-proof valve 3 is located can be the plane where the surface of the explosion-proof valve 3 facing the through-hole 415 is located, or the plane where the surface of the explosion-proof valve 3 facing the battery cell 1 is located, or any plane parallel to the surface of the explosion-proof valve 3 facing the through-hole 415 or the surface of the explosion-proof valve 3 facing the battery cell 1.

[0052] The following combines specific embodiments to evaluate the performance of the technical solutions provided by the embodiments of the present application.

[0053] Embodiments 1 to 5 are provided, where Embodiments 1 to 4 satisfy 0.0079mm 2 <S2 ≤ 58.9mm 2 , and Embodiment 5 does not satisfy 0.0079mm 2 <S2 ≤ 58.9mm 2 . The specific parameters and test results are shown in Table 1.

[0054] Table 1

[0055] Item <![CDATA[Total area of through holes S2 (mm 2 )]]> Initial bursting pressure value (MPa) Good rate of explosion-proof valve (%) Example 1 58.9 0.953 92.3 Example 2 10 1.03 99.8 Example 3 50 0.968 94.6 Example 4 40 0.981 97.1 Example 5 65 0.891 85.9

[0056] It should be noted that in the embodiments of the present application, the measurement method of the initial bursting pressure value is as follows: first, attach the pressure sensor to the explosion-proof valve 3 of the single battery cell, then heat the thermally triggered battery cell 1, and detect the initial bursting pressure value of the explosion-proof valve 3 through the pressure sensor. When calculating the yield rate of the explosion-proof valve, one is randomly selected from every 50 such single battery cells, and the percentage of the number of single battery cells with normal initial bursting pressure of the randomly selected explosion-proof valves in the total number of randomly selected single battery cells is the yield rate of the explosion-proof valve.

[0057] It can be seen from the table that in the above Embodiments 1 to 4, when the total area of the through-holes 415 satisfies 0.0079mm 2 <S2 ≤ 58.9mm 2 , the yield rate of the explosion-proof valve 3 in the single battery cell is high, and the explosion-proof member 4 can play a good protective role for the explosion-proof valve 3.

[0058] Refer to Figure 3 and Figure 9, the single cell further includes a terminal post 5, the terminal post 5 penetrates through the cover plate 2, one end of the terminal post 5 extends into the cavity 61 and is connected to the battery cell 1, and the other end exposes on the surface of the cover plate 2 facing away from the cavity 61. In the first direction Z, the size of the explosion-proof member 4 is L1 mm, and the distance from the end face of the terminal post 5 exposed on the cover plate 2 to the surface of the cover plate 2 facing the explosion-proof member 4 is L2 mm, and L1 ≤ L2. That is to say, the height of the explosion-proof member 4 in the first direction Z is less than or equal to the height of the terminal post 5. During the assembly and transportation of the single cell, it can protect the explosion-proof member 4, making the explosion-proof member 4 not easily worn, thereby ensuring the quality of the explosion-proof member 4 and the quality of the explosion-proof valve 3, thus ensuring the service life of the explosion-proof member 4, and further ensuring the service life of the explosion-proof valve 3, and ensuring the safety and reliability of the battery cell 1.

[0059] It is not difficult to understand that in other embodiments, the size of the explosion-proof member 4 can also be larger than the size of the terminal post 5 exposed on the surface of the cover plate 2 facing away from the cavity 61, which is not limited herein.

[0060] In some embodiments, the explosion-proof member 4 is detachably connected to the cover plate 2. Specifically, the explosion-proof member 4 can be bonded to the cover plate 2 by glue and disassembled by dissolving the glue with a solvent. In other embodiments, the explosion-proof member 4 can also be snap-connected or fixedly connected to the cover plate 2, such as by welding, etc., which is not limited herein.

[0061] In addition, the present application also provides a battery pack including the above single cell. The battery pack provided by the present application can protect the explosion-proof valve 3 during the manufacturing and assembly of the single cell into the battery pack by arranging the explosion-proof member 4 around the explosion-proof valve 3, thereby effectively ensuring the quality of the explosion-proof valve 3 and improving the safety of the single cell; the explosion-proof member 4 adopts a convex structure design and has good strength, which can form good protection for the explosion-proof valve 3.

[0062] Further, referring to Figure 10 , Figure 10 shows a graph of the bursting pressure values of the explosion-proof valve 3 when the single cell with the explosion-proof member 4 and the single cell without the explosion-proof member 4 are assembled into a battery pack for aging prediction simulation. Specifically, for the battery pack assembled from the single cell with the explosion-proof member 4, the explosion-proof member 4 selected has a top wall 412 thickness of 4 mm, a circumferential wall 413 thickness of 3 mm, 325 through holes 415, and the aperture of each through hole 415 is 0.2 mm. From Figure 10It can be seen that the initial bursting pressure value of the single cell with the explosion-proof component 4 set is greater than that of the single cell without the explosion-proof component 4 set. As time goes by, although the bursting pressure values of both decrease, the bursting pressure value of the single cell with the explosion-proof component 4 set is still higher than that of the single cell without the explosion-proof component 4 set. Thus, it can be seen that by setting the explosion-proof component 4, the explosion-proof valve 3 can be protected during the manufacturing of the single cell and the assembly into the battery pack, ensuring the bursting pressure value of the single cell, effectively improving the service life of the explosion-proof valve 3, and ensuring the safety of the single cell.

[0063] As described above, only some implementation manners of the embodiments of the present application are provided, and there is no any form of limitation to this application. The protection scope of the embodiments of the present application is not limited thereto. Any simple modification, equivalent change and modification that can be easily thought of by those skilled in the technical field of the present application within the technical scope disclosed by the embodiments of the present application should be covered within the protection scope of the embodiments of the present application.

Claims

1. A single cell battery, characterized in that: The single battery has a first direction (Z), and the single battery comprises a battery core (1), a cover plate (2), an explosion-proof valve (3), an explosion-proof component (4) and a shell (6); The cover plate (2) is arranged at one end of the shell (6) in the first direction (Z), the cover plate (2) cooperates with the shell (6) to enclose a cavity (61), and the battery cell (1) is arranged in the cavity (61); the cover plate (2) is provided with an explosion-proof hole (21); The explosion-proof valve (3) is connected to the cover plate (2) and covers the explosion-proof hole (21); The explosion-proof component (4) is arranged on a side of the cover plate (2) away from the battery core (1), and comprises a convex portion (41) and a connecting portion (42) connected to the convex portion (41); the convex portion (41) is arranged opposite to the explosion-proof valve (3); the convex portion (41) protrudes in a direction away from the explosion-proof valve (3); the convex portion (41) has a groove (411); the notch of the groove (411) faces the cover plate (2); the explosion-proof valve (3) is arranged opposite to the notch; and the connecting portion (42) is connected to the cover plate (2).

2. The single cell according to claim 1, characterized in that: The convex portion (41) comprises a top wall (412) and a circumferential wall (413); the top wall (412) is spaced apart from the cover plate (2); one end of the circumferential wall (413) is connected to the top wall (412) and the other end is connected to the connecting portion (42).

3. The single cell according to claim 2, characterized in that: The connecting portion (42) is connected to one end of the circumferential wall (413) away from the top wall (412), and along the direction from the top wall (412) to the cover plate (2), the distance between the connecting portion (42) and the axis (414) of the convex portion (41) gradually increases.

4. The single cell according to claim 2, characterized in that: The thickness of the top wall (412) is smaller than the thickness of the circumferential wall (413).

5. The single cell according to claim 2, characterized in that: The distance between the top wall (412) and the explosion-proof valve (3) is greater than the thickness of the top wall (412); The convex portion (41) further includes a connecting wall (416), wherein the connecting wall (416) is respectively connected to the top wall (412) and the circumferential wall (413); the top wall (412) and the circumferential wall (413) are arranged at an angle, and an included angle α between the top wall (412) and the circumferential wall (413) satisfies: 60°≤α≤120°.

6. The single cell according to claim 1, characterized in that: The bursting pressure value of the convex portion (41) is smaller than the bursting pressure value of the explosion-proof valve (3); And / or, the explosion-proof component (4) is detachably connected to the cover plate (2).

7. The single cell according to claim 1, characterized in that: The convex portion (41) is provided with one or more through holes (415), and the through holes (415) are respectively connected to the groove (411) and the outside of the convex portion (41).

8. The single cell according to claim 7, characterized in that: The area enclosed by the orthographic projection of each through hole (415) on the plane where the extension trend of the explosion-proof valve (3) is located is S1 mm 2 , meet: 0.0079mm 2 ≤S1≤19.6mm 2 ; The total area of ​​all through holes (415) is S2 mm 2 , meet: 0.0079mm 2 <S2≤58.9mm 2 .

9. The single cell according to claim 1, characterized in that: The single cell battery further comprises a pole (5), wherein the pole (5) is disposed through the cover plate (2), one end of the pole (5) extends into the cavity (61) and is connected to the battery cell (1), and the other end is exposed on a surface of the cover plate (2) facing away from the cavity (61); In the first direction (Z), the size of the explosion-proof component (4) is L1 mm, the distance from the end surface of the pole (5) exposed from the cover plate (2) to the surface of the cover plate (2) facing the explosion-proof component (4) is L2 mm, and L1≤L2.

10. A battery pack, characterized in that: The invention comprises a single cell as claimed in any one of claims 1 to 9.

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