Explosion-proof valve group, battery cell, battery module, battery pack and vehicle

Abstract

The utility model relates to the technical field of power batteries, in particular to an anti-explosion valve group, a battery cell, a battery module, a battery pack and a vehicle. The anti-explosion valve set comprises a first anti-explosion valve and a second anti-explosion valve, the valve opening pressure of the first anti-explosion valve is smaller than that of the second anti-explosion valve, and the first anti-explosion valve and the second anti-explosion valve are arranged in a clearance mode. The valve opening pressure of the first anti-explosion valve is smaller than that of the second anti-explosion valve, so that when the battery cell is subjected to thermal runaway, the first anti-explosion valve is opened, the pressure of jet gas of the battery cell subjected to thermal runaway is not large, the second anti-explosion valve is not opened, and if the internal pressure of the battery cell is continuously increased, the second anti-explosion valve is opened, so that heat in the battery cell is dissipated as soon as possible; the first anti-explosion valve and the second anti-explosion valve are opened step by step according to the internal pressure of the battery cell, so that the structural strength of the battery cell cannot be reduced after the first anti-explosion valve is opened, and the stability of the anti-explosion valves is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to power battery technical field especially relates to a kind of explosion-proof valve group, electric core, battery module, battery pack and vehicle. BACKGROUND

[0002] In the prior art, to ensure that the power battery has high capacity, good safety and cycle life, the electric core is generally provided with an explosion-proof valve. When the electric core is subjected to special conditions (such as thermal runaway and short circuit), the explosion-proof valve of the electric core can be opened in time to discharge the high-temperature gas generated inside the electric core, thereby improving the safety of the electric core.

[0003] Due to the limited area of the end face of the electric core, a single explosion-proof valve that is too long can reduce the stability of the explosion-proof valve itself, and a single explosion-proof valve that is too large can reduce the structural strength of the shell of the electric core. Therefore, in the related art, the cover or shell of the lithium battery is often broken when the electric core experiences thermal runaway, resulting in an uncontrolled direction of discharge and increasing the risk of thermal runaway of the battery pack.

[0004] Therefore, there is an urgent need for an explosion-proof valve group to solve the above technical problems. SUMMARY

[0005] The utility model aims at providing an explosion-proof valve group, an electric core, a battery module, a battery pack and a vehicle, which can realize step-by-step opening of the explosion-proof valve according to the internal pressure of the electric core after thermal runaway of the electric core, thereby reducing the risk of thermal runaway.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] In a first aspect, an explosion-proof valve group is provided, comprising a first explosion-proof valve and a second explosion-proof valve, the opening pressure of the first explosion-proof valve being less than the opening pressure of the second explosion-proof valve, and the first explosion-proof valve and the second explosion-proof valve being arranged with a gap.

[0008] As a preferred technical solution of the above explosion-proof valve group, the number of the second explosion-proof valves is multiple, the opening pressures of the multiple second explosion-proof valves have a trend of gradually increasing, and the multiple second explosion-proof valves are arranged with a gap.

[0009] As a preferred technical solution of the above explosion-proof valve group, a third explosion-proof valve is further included, the opening pressure of the third explosion-proof valve being greater than the opening pressure of the second explosion-proof valve, and the first explosion-proof valve and the second explosion-proof valve being located within the area formed by the third explosion-proof valve.

[0010] As a preferred technical solution of the above explosion-proof valve group, the ratio of the sum of the areas of the first explosion-proof valve and the second explosion-proof valve to the area of the third explosion-proof valve is 0.1-0.9.

[0011] In a second aspect, the utility model also provides a kind of electric core, the electric core has first end face and second end face, the second end face is oppositely arranged with the first end face, the first end face is the bottom surface of the electric core, the first end face is provided with the explosion-proof valve group of any one scheme described above, and the second end face is provided with pole post.

[0012] As a preferred technical scheme of the above-mentioned electric core, at least part of the explosion-proof valves in the explosion-proof valve group are formed by the score provided in the electric core; and / or,

[0013] The first end face is provided with first explosion-proof hole and second explosion-proof hole arranged in gaps, the first explosion-proof hole is covered with first explosion-proof valve sheet to form the first explosion-proof valve, and the second explosion-proof hole is covered with second explosion-proof valve sheet to form the second explosion-proof valve.

[0014] As a preferred technical scheme of the above-mentioned electric core, the explosion-proof valve group further includes a third explosion-proof valve, the opening pressure of the third explosion-proof valve is greater than that of the second explosion-proof valve, the first explosion-proof valve and the second explosion-proof valve are located within the area surrounded by the third explosion-proof valve, at least part of the explosion-proof valves in the explosion-proof valve group are formed by the score provided in the electric core; and / or,

[0015] The electric core is provided with a third explosion-proof valve hole, the third explosion-proof valve hole is covered with a third explosion-proof valve sheet to form the third explosion-proof valve, the third explosion-proof valve sheet is provided with first explosion-proof hole and second explosion-proof hole arranged in gaps, the first explosion-proof hole is covered with first explosion-proof valve sheet to form the first explosion-proof valve, and the second explosion-proof hole is covered with second explosion-proof valve sheet to form the second explosion-proof valve.

[0016] As a preferred technical scheme of the above-mentioned electric core, the ratio of the area of the third explosion-proof valve to the total area S of the first end face is 0.1-0.9.

[0017] As a preferred technical scheme of the above-mentioned electric core, the score is provided in the inner wall of the electric core; and / or,

[0018] The first explosion-proof valve sheet, the second explosion-proof valve sheet and the third explosion-proof valve sheet are all provided in the outer wall of the electric core.

[0019] In a third aspect, the utility model also provides a kind of battery module, including the electric core described in any one of the above, and multiple electric cores are electrically connected.

[0020] In a fourth aspect, the utility model also provides a kind of battery pack, including the battery module described above.

[0021] In a fifth aspect, the utility model also provides a kind of vehicle, including the battery pack described above.

[0022] The utility model discloses at least has following beneficial effect:

[0023] The explosion-proof valve group, the electric core, the battery module, the battery pack and the vehicle provided by the utility model, since the opening valve pressure of the first explosion-proof valve is less than the opening valve pressure of the second explosion-proof valve, when the electric core is in thermal runaway, the first explosion-proof valve will be opened first, if the gas pressure ejected by the electric core in thermal runaway is not high, the second explosion-proof valve will not be opened, if the internal pressure of the electric core continues to rise, the second explosion-proof valve will be opened, and then the heat in the electric core is discharged as soon as possible, so that the internal structure of the electric core is prevented from being damaged, since the first explosion-proof valve and the second explosion-proof valve are opened gradually according to the internal pressure of the electric core, when the second explosion-proof valve is opened, the structural strength of the electric core is not reduced, and the stability of the explosion-proof valve is ensured, the combination of the second explosion-proof valve and the first explosion-proof valve can increase the actual ejection area of the explosion-proof valve group, and the directional ejection of the electric core is ensured, and the risk of thermal runaway of the battery pack is reduced.

[0024] Since the first explosion-proof valve that should be opened in advance is not opened, the internal pressure increases sharply, and enough area is needed for pressure relief at the moment of opening the valve, therefore, the area of the second explosion-proof valve needs to be large enough, and the setting of the plurality of second explosion-proof valves ensures the safe opening of the valve in this failure mode.

[0025] In addition, since the first explosion-proof valve and the second explosion-proof valve are arranged in the area formed by the third explosion-proof valve, that is, the first explosion-proof valve and the second explosion-proof valve are completely opened after the third explosion-proof valve is opened, the third explosion-proof valve can also avoid the situation that the first explosion-proof valve and the second explosion-proof valve are not opened on time or fail to be opened, and the last third explosion-proof valve is opened, so that the final explosion-proof valve group can be opened. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical scheme in the embodiments of the utility model, the drawings needed to be used in the description of the embodiments of the utility model will be briefly introduced, and obviously, the drawings in the following description are only some embodiments of the utility model, and other drawings can be obtained according to the contents of the embodiments of the utility model and these drawings by the ordinary skilled in the art without creating the creative labor.

[0027] Figure 1 The bottom view of the electric core provided by the embodiments of the utility model Figure 1 ;

[0028] Figure 2 The bottom view of the electric core provided by the embodiments of the utility model Figure 2 ;

[0029] Figure 3 The bottom view of the electric core provided by the embodiments of the utility model Figure 3 ;

[0030] Figure 4 The bottom view of the battery cell provided by the embodiment of the utility model Figure 4

[0031] Figure 5 The structure diagram of the battery cell provided by the embodiment of the utility model Figure 1 ;

[0032] Figure 2 The structure diagram of the battery cell provided by the embodiment of the utility model Figure 1 .

[0033] In the drawings:

[0034] 10, battery cell; 1, first end face; 2, pole; 3, first explosion-proof valve; 4, second explosion-proof valve; 5, third explosion-proof valve. DETAILED DESCRIPTION

[0035] The utility model will be explained in further detail below in connection with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the utility model and are not limited to the utility model. In addition, it should be noted that, in order to facilitate the description, only the parts related to the utility model are shown in the drawings, not all the structures.

[0036] In the description of the utility model, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0037] In the utility model, unless otherwise explicitly specified and limited, the first feature is "on" or "below" the second feature, which can include that the first and second features are in direct contact, or the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0038] ​In the description of the embodiments, the terms "upper", "lower", "right", "left", and the like, orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0039] The conventional battery cell has only a single explosion-proof valve, and the area of the spray port after the explosion-proof valve is opened is fixed. If the spray amount of the battery cell during thermal runaway is too large and the area of the spray port is fixed, the area of the spray port may be too small to cause the internal pressure of the battery cell to increase, causing the shell or cover plate to break, resulting in unidirectional spraying.

[0040] Therefore, the embodiment of the utility model provides an explosion-proof valve group which can realize step-by-step opening of the explosion-proof valve according to the internal pressure of the battery cell, thereby increasing the actual spray area of the explosion-proof valve and preventing the shell or cover plate from breaking.

[0041] As shown in Figure 2 and Figure 2 , the explosion-proof valve group includes a first explosion-proof valve 3 and a second explosion-proof valve 4, the opening pressure of the first explosion-proof valve 3 is less than that of the second explosion-proof valve 4, and the first explosion-proof valve 3 and the second explosion-proof valve 4 are arranged with a gap.

[0042] The opening pressure of the first explosion-proof valve 3 is less than that of the second explosion-proof valve 4, so when the battery cell experiences thermal runaway, the first explosion-proof valve 3 will be opened. If the gas pressure sprayed by the battery cell during thermal runaway is not large, the second explosion-proof valve 4 will not be opened. If the internal pressure of the battery cell continues to rise, the second explosion-proof valve 4 will be opened, thereby quickly dissipating the heat in the battery cell and preventing structural damage to the battery cell. Since the first explosion-proof valve 3 and the second explosion-proof valve 4 are opened step by step according to the internal pressure of the battery cell, the opening of the first explosion-proof valve 3 will not reduce the structural strength of the battery cell and ensure the stability of the explosion-proof valve, and also ensure the directional spraying of the battery cell and reduce the risk of thermal runaway of the battery pack. The second explosion-proof valve 4 can also avoid the situation where the first explosion-proof valve 3 does not open on time or fails to open, and the last second explosion-proof valve 4 is opened, ensuring that the final explosion-proof valve group can be opened.

[0043] In some embodiments, as shown in Figures 3 to 5 , the number of second explosion-proof valves 4 is multiple, and the opening pressures of the multiple second explosion-proof valves 4 have a step-by-step increasing trend. For example, the opening pressures of the multiple second explosion-proof valves 4 increase step by step in the form of an arithmetic sequence or a geometric sequence. The multiple second explosion-proof valves 4 are arranged with a gap, that is, the multiple second explosion-proof valves 4 are arranged without contact and without overlapping. In this way, the arrangement of the multiple second explosion-proof valves 4 can make the area of the explosion-proof valve group large enough to meet the safety opening requirement.

[0044] Since the first explosion-proof valve 3, which should have opened in advance, failed to open, the internal pressure increased sharply. Therefore, there must be enough area for pressure relief at the moment of valve opening. Thus, the area of ​​the second explosion-proof valve 4 must be large enough. The setting of multiple second explosion-proof valves 4 ensures the safe valve opening requirement in this failure mode.

[0045] In some other embodiments, at least some of the second explosion-proof valves 4 have different opening pressures to ensure that the second explosion-proof valves 4 can open in stages, and the opening area is increased to adapt to different opening requirements. For example, the center of the second explosion-proof valve 4 with the lowest opening pressure coincides with the center of the first end face 1. In this way, after the second explosion-proof valve 4 with the lowest opening pressure is opened, the high-temperature gas from all parts of the battery cell can be quickly discharged into the battery cell, avoiding the extension of the flow path of the high-temperature gas in the battery cell, and also preventing internal structural failure caused by thermal runaway of the battery cell.

[0046] In some embodiments, such as Figure 6 As shown, the explosion-proof valve assembly also includes a third explosion-proof valve 5. The opening pressure of the third explosion-proof valve 5 is greater than that of the second explosion-proof valve 4. The first explosion-proof valve 3 and the second explosion-proof valve are located within the area formed by the third explosion-proof valve. The installation of the third explosion-proof valve 5 further increases the overall area of ​​the explosion-proof valve assembly. Since the first explosion-proof valve 3 and the second explosion-proof valve 4 are located within the area formed by the third explosion-proof valve 5, meaning that the first explosion-proof valve 3 and the second explosion-proof valve 4 are already fully open after the third explosion-proof valve 5 is opened, the installation of the third explosion-proof valve 5 also prevents the first explosion-proof valve 3 and the second explosion-proof valve 4 from failing to open on time or malfunctioning and being unable to open, ensuring that the final explosion-proof valve assembly can open.

[0047] In some embodiments, the opening pressure of each explosion-proof valve is different. The opening pressure gradient is: the first explosion-proof valve 3 < the second explosion-proof valve 4 < the third explosion-proof valve 5 < the pressure resistance of the battery cell 10, which includes a shell and a cover plate. Generally, the pressure resistance of the welding seam of the aluminum shell and cover plate after welding is generally below 2 MPa, and the opening pressure of the third explosion-proof valve 5 is < 2 MPa. The opening pressure of the first explosion-proof valve 3 is ≥ 0.4 MPa, and the opening pressure of the second explosion-proof valve 4 is > 0.4 MPa. At the same time, the maximum opening pressure of each second explosion-proof valve 4 is < the minimum opening pressure of the third explosion-proof valve 5. When the battery cell 10 is in thermal runaway, the first explosion-proof valve 3 will normally open to release pressure, but the gas production of the high-nickel system battery cell 10 is huge when it is in thermal runaway. The area of the ordinary explosion-proof valve cannot meet the design requirements, but increasing the area of a single explosion-proof valve will reduce the strength of the cover plate or the shell, and the opening pressure of the explosion-proof valve itself will fluctuate greatly. Therefore, a single explosion-proof valve cannot meet the design requirements. In the design of the utility model, when the first explosion-proof valve 3 opens, the battery cell 10 has been in thermal runaway, and the early gas production is mainly discharged through the first explosion-proof valve 3. When the first explosion-proof valve 3 cannot meet the pressure relief requirement, the internal pressure of the battery cell 10 continues to increase. When the internal pressure reaches the opening pressure of the second explosion-proof valve 4, the second explosion-proof valve 4 opens. At this time, the opening area is the sum of the areas of all second explosion-proof valves 4 and the first explosion-proof valve 3. The increased area improves the pressure relief rate. Similarly, if the second explosion-proof valve 4 does not meet the requirements, the third explosion-proof valve 5 will open, and the opening area is the largest.

[0048] In some embodiments, the ratio of the sum of the areas of the first explosion-proof valve 3 and the second explosion-proof valve 4 to the area of the third explosion-proof valve 5 is 0.1-0.9. For example, the ratio of the sum of the areas of the first explosion-proof valve 3 and the second explosion-proof valve 4 to the area of the third explosion-proof valve 5 can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9, which is not limited in the embodiment. When the ratio of the sum of the areas of the first explosion-proof valve 3 and the second explosion-proof valve 4 to the area of the third explosion-proof valve 5 is 0.9, the overall area of the explosion-proof valve group can be increased. When the ratio of the sum of the areas of the first explosion-proof valve 3 and the second explosion-proof valve 4 to the area of the third explosion-proof valve 5 is 0.1, the high-temperature substances can be ensured to be ejected.

[0049] In some embodiments, the shapes of the first explosion-proof valve 3 and the plurality of second explosion-proof valves 4 are not completely the same. In other embodiments, the shapes of the first explosion-proof valve 3 and the plurality of second explosion-proof valves 4 can also be the same. The shapes of the first explosion-proof valve 3 and the second explosion-proof valve 4 can be set according to actual needs. For example, the shapes can be rectangular, circular or elliptical, etc.

[0050] The utility model discloses still provide a kind of electric core 10, electric core 10 has first end face 1, first end face 1 is provided with the explosion-proof valve group of the utility model embodiment. Figure 1 As shown in the figure, the electric core 10 also has a second end face, which is oppositely arranged with the first end face 1, and the second end face is provided with a pole 2. The first end face 1 is the bottom surface of the electric core 10, and the second end face is the top surface of the electric core 10. The pole 2 and the explosion-proof valve group are not arranged on the same end face, thereby avoiding the short circuit of the pole 2 caused by the high-temperature substances acting on the pole 2 after the explosion of the explosion-proof valve group, which affects the overall battery pack.

[0051] Due to the arrangement of the explosion-proof valve group on the electric core 10, the explosion-proof valve group includes a first explosion-proof valve 3 and a second explosion-proof valve 4. The opening pressure of the first explosion-proof valve 3 is less than that of the second explosion-proof valve 4. When the electric core 10 experiences thermal runaway, the first explosion-proof valve 3 will be opened. If the gas pressure ejected by the electric core 10 during thermal runaway is not high, the second explosion-proof valve 4 will not be opened. If the internal pressure of the electric core 10 continues to rise, the second explosion-proof valve 4 will be opened, thereby quickly dissipating the heat inside the electric core 10 and avoiding structural damage inside the electric core 10. Since the first explosion-proof valve 3 and the second explosion-proof valve 4 are opened in stages according to the internal pressure of the electric core 10, the opening of the first explosion-proof valve 3 will not reduce the structural strength of the electric core 10 and ensure the stability of the explosion-proof valve. It also ensures the directional ejection of the electric core 10 and reduces the risk of thermal runaway of the battery pack. The arrangement of the second explosion-proof valve 4 can also avoid the situation where the first explosion-proof valve 3 does not open on time or fails to open, and ensure that the final explosion-proof valve group can be opened.

[0052] In some embodiments, the ratio of the area of the third explosion-proof valve 5 to the total area S of the first end face 1 is 0.1-0.9. For example, the ratio of the area of the third explosion-proof valve 5 to the total area S of the first end face 1 can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9, which is not limited in the present embodiment. The ratio of the area of the third explosion-proof valve 5 to the total area S of the first end face 1 is 0.9, which can increase the overall area of the explosion-proof valve group. The ratio of the area of the third explosion-proof valve 5 to the total area S of the first end face 1 is 0.1, which can ensure that the high-temperature substances are ejected.

[0053] In some embodiments, at least part of the explosion-proof valves in the explosion-proof valve group are formed by notches arranged on the shell. For example, the notches are arranged on the shell as shown in Figure 2 and Figures 3 to 5As shown, the first end face 1 is provided with grooves, which form the first explosion-proof valve 3 and the second explosion-proof valve 4. The grooves are on the outer wall of the battery cell 10, which facilitates processing. In some embodiments, in order to avoid contamination and corrosion of the grooves of the explosion-proof valves by external foreign objects, the grooves of the explosion-proof valves can be set on the inner wall of the battery cell 10.

[0054] like ​ As shown, the first end face is provided with grooves, which form the first explosion-proof valve 3, the second explosion-proof valve 4, and the third explosion-proof valve 5. The grooves are located on the outer wall of the battery cell 10, which facilitates processing. In some embodiments, in order to avoid contamination and corrosion of the grooves on the explosion-proof valves by external foreign objects, the grooves on the explosion-proof valves can be located on the inner wall of the battery cell 10.

[0055] For example, the second explosion-proof valve 4, the first explosion-proof valve 3, and the third explosion-proof valve 5 are all formed by grooves provided on the battery cell 10. The first explosion-proof valve 3 and multiple second explosion-proof valves 4 are spaced apart, with each second explosion-proof valve 4 having a different groove depth to ensure that the second explosion-proof valves 4 open sequentially. In other examples, some second explosion-proof valves 4 are spaced apart, while others are sequentially nested from the outside in, with different opening pressures for each second explosion-proof valve 4 to ensure that the second explosion-proof valves 4 open sequentially.

[0056] It should be noted that the groove depth of the first explosion-proof valve 3 is greater than that of the second explosion-proof valve 4, and the groove depth of each of the multiple second explosion-proof valves 4 is different to ensure that the opening pressure of each second explosion-proof valve 4 is different. The grooves of the explosion-proof valve assembly are directly stamped out on the first end face 1 of the battery cell 10 using stamping technology. By precisely adjusting the groove depth, the opening pressure of the explosion-proof valve can be precisely controlled, which can reduce the production cost of structural components and further reduce the cost of the battery cell.

[0057] In other embodiments, the first end face 1 is provided with a first explosion-proof hole and a second explosion-proof hole. The first explosion-proof hole covers a first explosion-proof valve plate to form a first explosion-proof valve 3, and the second explosion-proof valve hole covers a second explosion-proof plate to form a second explosion-proof valve 4. There can be multiple second explosion-proof holes, which are spaced apart. The specific number can be determined according to the requirements of the second explosion-proof valve 4.

[0058] In some embodiments, the first end face 1 is provided with a third explosion-proof hole, the third explosion-proof hole is covered with a third explosion-proof sheet to form a third explosion-proof valve 5, and the third explosion-proof sheet is provided with a first explosion-proof hole and a second explosion-proof hole, the second explosion-proof hole is covered with a second explosion-proof valve sheet to form a second explosion-proof valve 4, and the first explosion-proof hole is covered with a first explosion-proof valve sheet to form a first explosion-proof valve. The number of the second explosion-proof holes can be multiple, the multiple second explosion-proof holes are arranged at intervals along the length direction of the first end face 1, and when the number of the second explosion-proof holes is multiple, the shapes of the second explosion-proof holes can be the same or different, but at least part of the second explosion-proof holes correspond to the second explosion-proof valve sheets with different opening valve pressures, thereby adapting to the opening valve requirements of the battery cells with different pressures, and at the same time, the opening valve pressure of the second explosion-proof valve sheet can be prevented from being too large to reduce the overall strength of the battery cell 10, and the stability of the explosion-proof valve itself can be ensured. The number of the second explosion-proof holes is set according to the length of the third explosion-proof valve sheet. The arrangement of the second explosion-proof hole and the first explosion-proof hole can ensure that the high-temperature substances are sprayed out from the second explosion-proof hole and the first explosion-proof hole, and the explosion-proof valve sheet is welded at the explosion-proof hole of the first end face by a welding scheme, and the welding can be performed on the outside of the battery cell 10 or on the inside.

[0059] In some embodiments, the ratio of the sum of the areas of the second explosion-proof hole and the first explosion-proof hole to the area of the third explosion-proof hole is 0.1-0.9. For example, the ratio of the sum of the areas of the second explosion-proof hole and the first explosion-proof hole to the area of the third explosion-proof hole can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9, which is not specifically limited in the present embodiment. When the ratio of the sum of the areas of the second explosion-proof hole and the first explosion-proof hole to the area of the third explosion-proof hole is 0.9, the overall area of the explosion-proof valve group can be increased. When the ratio of the sum of the areas of the second explosion-proof hole and the first explosion-proof hole to the area of the third explosion-proof hole is 0.1, the high-temperature substances can be ensured to be sprayed out.

[0060] In some embodiments, the ratio of the area of the third explosion-proof hole to the total area S of the first end face 1 is 0.1-0.9. For example, the ratio of the area of the third explosion-proof hole to the total area S of the first end face 1 can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9, which is not specifically limited in the present embodiment. When the ratio of the area of the third explosion-proof hole to the total area S of the first end face 1 is 0.9, the overall area of the explosion-proof valve group can be increased. When the ratio of the area of the third explosion-proof hole to the total area S of the first end face 1 is 0.1, the high-temperature substances can be ensured to be sprayed out.

[0061] In some embodiments, the shapes of the third explosion-proof hole, the second explosion-proof hole and the first explosion-proof hole are not completely the same. For example, the shapes of the second explosion-proof hole and the third explosion-proof hole are rectangular, and the shape of the first explosion-proof hole is elliptical. Alternatively, the shape of the second explosion-proof hole is elliptical, and the shapes of the first explosion-proof hole and the third explosion-proof hole are rectangular.

[0062] For example, the first end surface 1 is provided with a score, a first explosion-proof hole and a plurality of second explosion-proof holes, the second explosion-proof holes are covered with second explosion-proof valve pieces, and the second explosion-proof holes are located in the area surrounded by the score.

[0063] In other examples, the first end surface is provided with an explosion-proof hole, wherein the explosion-proof hole is a first explosion-proof hole, the first explosion-proof hole is covered with a first explosion-proof valve piece, and the first explosion-proof valve piece is provided with a score of different depths.

[0064] The embodiment of the utility model further provides a battery module, including a plurality of above-mentioned embodiment provides electric core 10, a plurality of electric core 10 series parallel connection electric connection.

[0065] Since including above-mentioned electric core 10, the battery module of the embodiment of the utility model has all the advantages and beneficial effects of the above-mentioned embodiment, which will not be repeated here.

[0066] The embodiment of the utility model further provides a battery pack, including a shell and the battery module provided by the above-mentioned embodiment, and the battery module is arranged in the shell.

[0067] Since including above-mentioned battery module, the battery pack of the embodiment of the utility model has all the advantages and beneficial effects of the above-mentioned embodiment, which will not be repeated here.

[0068] The embodiment of the utility model further provides a vehicle, including the battery pack provided by the embodiment of the utility model.

[0069] Since including above-mentioned battery pack, the vehicle of the embodiment of the utility model has all the advantages and beneficial effects of the above-mentioned embodiment, which will not be repeated here.

[0070] In addition, the above-mentioned is only the preferred embodiment of the utility model and the technical principle applied. The person skilled in the art will understand that the utility model is not limited to the specific embodiments described herein, and those skilled in the art can make various obvious changes, re-adjustment and replacement without departing from the protection scope of the utility model. Therefore, although the utility model is more specifically described through the above embodiments, the utility model is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the utility model, and the scope of the utility model is determined by the appended claims.

Claims

1. A battery cell, characterized in that, The battery cell has a first end face (1) and a second end face, the second end face being disposed opposite to the first end face (1), the first end face (1) being the bottom surface of the battery cell, the first end face (1) being provided with an explosion-proof valve group, the second end face being provided with a pole post (2), the explosion-proof valve group including a first explosion-proof valve (3) and a second explosion-proof valve (4), the opening pressure of the first explosion-proof valve (3) being less than the opening pressure of the second explosion-proof valve (4), and the first explosion-proof valve (3) and the second explosion-proof valve (4) being disposed with a gap.

2. The battery cell according to claim 1, characterized in that, There are multiple second explosion-proof valves (4), and the opening pressure of the multiple second explosion-proof valves (4) increases step by step. The multiple second explosion-proof valves (4) are arranged in a gap.

3. The battery cell according to claim 1, characterized in that, It also includes a third explosion-proof valve (5), the opening pressure of which is greater than that of the second explosion-proof valve (4), and the first explosion-proof valve (3) and the second explosion-proof valve (4) are located in the area formed by the third explosion-proof valve (5).

4. The battery cell according to claim 3, characterized in that, The ratio of the sum of the areas of the first explosion-proof valve (3) and the second explosion-proof valve (4) to the area of ​​the third explosion-proof valve (5) is 0.1-0.

9.

5. The battery cell according to claim 1, characterized in that, At least a portion of the explosion-proof valves in the explosion-proof valve assembly are formed by indentations provided on the battery cell; and / or, The first end face (1) is provided with a first explosion-proof hole and a second explosion-proof hole that are spaced apart. The first explosion-proof hole is covered by a first explosion-proof valve plate to form the first explosion-proof valve (3), and the second explosion-proof hole is covered by a second explosion-proof valve plate to form the second explosion-proof valve (4).

6. The battery cell according to claim 1, characterized in that, The explosion-proof valve assembly further includes a third explosion-proof valve (5), the opening pressure of which is greater than that of the second explosion-proof valve (4). The first explosion-proof valve (3) and the second explosion-proof valve (4) are located within the area enclosed by the third explosion-proof valve (5). At least some of the explosion-proof valves in the explosion-proof valve assembly are formed by indentations provided on the battery cell; and / or, The battery cell is provided with a third explosion-proof valve hole, and the third explosion-proof valve hole is covered by a third explosion-proof valve plate to form the third explosion-proof valve (5). The third explosion-proof valve plate is provided with a first explosion-proof hole and a second explosion-proof hole that are spaced apart. The first explosion-proof hole is covered by a first explosion-proof valve plate to form the first explosion-proof valve (3), and the second explosion-proof hole is covered by a second explosion-proof valve plate to form the second explosion-proof valve (4).

7. The battery cell according to claim 6, characterized in that, The ratio of the area of ​​the third explosion-proof valve (5) to the total area S of the first end face (1) is 0.1-0.

9.

8. The battery cell according to claim 6, characterized in that, The grooves are provided on the inner wall of the battery cell; and / or, the first explosion-proof valve plate, the second explosion-proof valve plate, and the third explosion-proof valve plate are all provided on the outer wall of the battery cell.

9. A battery module, characterized in that, It includes a plurality of battery cells as described in any one of claims 1-8, and the plurality of battery cells are electrically connected.

10. A battery pack, characterized in that, Includes the battery module as described in claim 9.

11. A vehicle, characterized in that, Includes the battery pack as described in claim 10.

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