Battery monomer, pressure relief mechanism, battery device and power utilization device

Abstract

The utility model provides a single battery, a pressure relief mechanism, a battery device and a power utilization device, the single battery comprises a shell, an electrode assembly and the pressure relief mechanism, the shell is provided with a containing cavity, the electrode assembly is arranged in the containing cavity, the pressure relief mechanism is arranged on the shell, the pressure relief mechanism comprises a valve body, a first groove and a second groove, and the first groove and the second groove are formed in the valve body; the first grooves in pairs extend in the first direction and are mutually spaced in the second direction, a pressure relief space is formed between the first grooves, the size of the pressure relief space in the first direction is larger than the size of the pressure relief space in the second direction, the second grooves are connected to the first grooves in the two sides in the second direction and separate the pressure relief space, and the second direction intersects with the first direction. According to the battery monomer provided by the embodiment of the invention, the risk of ejection bias of high-temperature gas can be reduced, and the reliability of pressure relief of the battery monomer is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery monomer, a pressure relief mechanism, a battery device and a power utilization device. BACKGROUND

[0002] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy saving and environmental protection advantages. For electric vehicles, battery technology is an important factor for their development.

[0003] To solve the problem of high-temperature and high-pressure gas discharge generated by the electrode assembly under overcharging, failure and other conditions, a pressure relief mechanism is often installed on the battery. When high-temperature and high-pressure gas is generated, the notch on the pressure relief mechanism breaks to quickly exhaust the battery. However, the existing pressure relief mechanism is prone to side spraying, causing heat diffusion. Therefore, how to reduce the risk of side spraying of the pressure relief mechanism has become a problem to be solved. CONTENT OF THE UTILITY MODEL

[0004] In view of the above problems, the present application provides a battery monomer, a pressure relief mechanism, a battery device and a power utilization device, which can reduce the risk of high-temperature gas spraying bias and improve the reliability of the battery monomer pressure relief.

[0005] In the first aspect, the present application provides a battery monomer, comprising a shell, an electrode assembly and a pressure relief mechanism, the shell has a containing cavity, the electrode assembly is arranged in the containing cavity, and the pressure relief mechanism is arranged on the shell. The pressure relief mechanism comprises a valve body and a first groove and a second groove arranged on the valve body, the pair of first grooves extend along a first direction and are spaced apart from each other in a second direction, a pressure relief space is formed between the first grooves, and the size of the pressure relief space along the first direction is greater than the size along the second direction, the second groove is connected to the first grooves on both sides along the second direction and separates the pressure relief space, and the second direction intersects the first direction.

[0006] In the present application, by arranging the first groove and the second groove on the valve body, when the internal pressure of the battery monomer rises to a threshold value, the valve body will be separated from the shell at the second groove and the first groove and turned over to open on both sides, so that the high-temperature gas in the battery monomer can be sprayed in a direction perpendicular to the shell, reducing the risk of high-temperature gas spraying bias.

[0007] In some embodiments, the pair of first grooves are symmetrically arranged relative to the pressure relief space, and in the second direction, the two ends of the second groove are respectively connected to the middle part of the first groove, so that the valve body can be turned over and opened synchronously from both sides.

[0008] In some embodiments, the first groove comprises a first groove segment and a second groove segment arranged in intersection, the first groove segment extends along the first direction, and the second groove segment is oppositely arranged at two ends of the first groove segment along the first direction. In a pair of first grooves, the second groove segments of the two first grooves extend towards each other along the second direction by a distance and are oppositely arranged at the ends, which can increase the breaking length of the pressure relief mechanism, reduce the risk of secondary accidents caused by the whole valve body flying out when the valve is opened, and improve the reliability of the pressure relief mechanism.

[0009] In some embodiments, the pressure relief mechanism further comprises a third groove oppositely arranged along the first direction, and one end of the third groove is connected to one end of the pair of first grooves along the second direction, and the other end of the third groove is connected to the other end of the pair of first grooves along the second direction, and the depth of the third groove is less than the depth of the first groove, so that when the valve body is opened by turning over on both sides, the third groove remains connected, which can serve as a turning-over shaft, making it easier for the pressure relief mechanism to turn over and reducing the difficulty of turning over.

[0010] In some embodiments, the ratio of the size of the third groove along the second direction to the size of the pressure relief space along the second direction is 0.1-0.5, which can improve the strength of the connection, reduce the risk of cracking, facilitate the turning over of the valve body, and improve the reliability of the pressure relief.

[0011] In some embodiments, the shell comprises a shell body and a cover plate, the shell body has an opening, the cover plate is arranged at the opening and connected with the shell body, and at least one of the shell body and the cover plate is provided with a pressure relief mechanism.

[0012] In some embodiments, the shell body comprises a bottom wall and a plurality of side walls, the bottom wall and the plurality of side walls form a containing cavity with an opening, and the pressure relief mechanism is arranged on the bottom wall and / or the cover plate, which can reduce the influence of high-temperature gas in the battery monomer on other battery monomers after being sprayed in a direction perpendicular to the shell, and reduce the risk of heat diffusion.

[0013] In some embodiments, the plurality of side walls comprises a pair of first side walls and a pair of second side walls arranged oppositely, the area of the first side wall is greater than the area of the second side wall, the first direction is parallel to the arrangement direction of the second side wall, and the second direction is parallel to the arrangement direction of the first side wall, which can reduce the risk of rupture of the second groove due to expansion during the charging and discharging process of the battery monomer, and improve the reliability of the pressure relief mechanism.

[0014] In some embodiments, the plurality of side walls comprises a pair of first side walls and a pair of second side walls arranged oppositely, the area of the first side wall is greater than the area of the second side wall, the first direction is parallel to the arrangement direction of the first side wall, and the second direction is parallel to the arrangement direction of the second side wall, which can use the valve body to shield the high-temperature gas discharged from the pressure relief space, and can play a protective role to reduce the influence of the high-temperature gas on adjacent battery monomers.

[0015] In some embodiments, the shell comprises a pressure relief hole and a pressure relief mechanism arranged in the pressure relief hole, and a protective sheet arranged on the shell and covering the pressure relief hole; the shell is provided with an exhaust groove extending to the pressure relief hole and communicating with the pressure relief space, so that whether the pressure relief mechanism has a welding quality defect causing the electrolyte in the battery to leak can be determined by detecting the leakage at the exhaust groove.

[0016] In some embodiments, the number of exhaust grooves is multiple, and part of the exhaust grooves are arranged corresponding to the first groove and part of the exhaust grooves are arranged corresponding to the second groove, which can more reliably detect the pressure relief mechanism to improve the reliability of the pressure relief mechanism.

[0017] In some embodiments, the material of at least part of the shell comprises one of the following materials: steel, aluminum alloy and titanium alloy. These materials are resistant to high temperature and have high tensile strength, which can meet the strength requirements of the shell, and are easy to process and have low cost.

[0018] In some embodiments, the material of at least part of the shell comprises stainless steel or carbon steel. If the shell is made of stainless steel, it has high structural strength and can generally meet the requirements of tensile strength under high temperature conditions. In addition, the shell made of stainless steel is not prone to rust, which can improve the service life of the shell compared with other materials. If the shell is made of carbon steel, it has high structural strength and can easily meet the requirements of tensile strength under high temperature conditions.

[0019] In some embodiments, the material of at least part of the valve body comprises one of the following materials: steel, aluminum alloy, copper-tin-nickel alloy and titanium alloy.

[0020] In some embodiments, the material of at least part of the valve body is the same as the material of at least part of the shell, which can make it easier to weld the valve body to the shell. At the same time, the valve body and the shell also have high melting points, which can reduce the risk of melting of the valve body and the shell in the case of thermal runaway.

[0021] In some embodiments, the electrode assembly comprises a positive electrode sheet, the positive electrode sheet comprises a positive electrode active material capable of reversible extraction-embedding metal ions, and the positive electrode active material comprises a nickel-containing element compound.

[0022] By making the positive electrode active material of the positive electrode sheet include a nickel-containing element compound, the energy density and long cycle life of the battery cell can be effectively increased. Although it may also increase the gas generated in the case of thermal runaway of the battery cell, by arranging the above groove structure, the reliable discharge of high-temperature gas can also be achieved in the case of the positive electrode active material including a nickel-containing element compound, thereby improving the pressure relief reliability.

[0023] In a second aspect, the embodiments of the present application provide a pressure relief mechanism, comprising a valve body and a first groove and a second groove arranged on the valve body. The first grooves are arranged in pairs and extend along a first direction and are spaced apart from each other along a second direction, a pressure relief space is formed between the first grooves, and the size of the pressure relief space along the first direction is greater than the size along the second direction. The second groove is connected to the first grooves on both sides along the second direction and separates the pressure relief space, and the second direction intersects the first direction.

[0024] In a third aspect, the embodiments of the present application provide a battery device, comprising a plurality of the battery cells of the first aspect.

[0025] In a fourth aspect, the embodiments of the present application provide a power consumption device, comprising the battery device of the third aspect.

[0026] According to the battery cell of the embodiments of the present application, the battery cell comprises a shell, an electrode assembly, and a pressure relief mechanism. By arranging the second groove between the first grooves arranged in pairs, when the internal pressure of the battery cell rises to a threshold value, the valve body will be separated from the shell at the second groove and the first groove and will be flipped open to both sides, so that the high-temperature gas in the battery cell can be sprayed in a direction perpendicular to the shell, thereby reducing the risk of high-temperature gas spray deviation. In addition, by making the size of the pressure relief space along the first direction greater than the size along the second direction, and arranging the second groove to extend along the second direction, the size of the second groove can be reduced, thereby reducing the risk of cracking of the second groove before the valve is opened, and at the same time, after the valve is opened, the force arm of the flip can also be increased, thereby being more easily flipped under the same force, and the reliability of the pressure relief mechanism is improved.

[0027] The above description is only a summary of the technical solutions of the present application. In order to enable the technical means of the present application to be more clearly understood, the embodiments of the present application can be implemented in accordance with the content of the description, and in order to enable the above and other purposes, features and advantages of the present application to be more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0028] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a better understanding of the preferred embodiments, and are not considered limiting of the present application. Moreover, like reference numerals denote like elements throughout the accompanying drawings. In the drawings:

[0029] Figure 1 is a structural schematic diagram of a vehicle provided by some embodiments of the present application;

[0030] Figure 2 is an exploded schematic diagram of a battery device provided by some embodiments of the present application;

[0031] Figure 3 is an exploded diagram of a battery cell provided by some embodiments of the present application;

[0032] Figure 4 is a front view of a pressure relief mechanism provided by some embodiments of the present application;

[0033] Figure 5 is a structural schematic view of a battery monomer from one angle provided by some embodiments of the present application;

[0034] Figure 6 is a structural schematic view of a battery monomer from another angle provided by some embodiments of the present application;

[0035] Figure 7 is a sectional view of a battery monomer provided by some embodiments of the present application;

[0036] Figure 8 is an enlarged view of A in FIG. 1; Figure 7

[0037] Figure 9 is a sectional view of E-E direction in FIG. 1; Figure 7

[0038] Figure 10 is an enlarged view of B in FIG. 1; Figure 9

[0039] Figure 11 is an enlarged view of C in FIG. 1; Figure 7

[0040] Figure 12 is a bottom view of a battery monomer provided by some embodiments of the present application.

[0041] In the drawings:

[0042] 100 battery device, 200 controller, 300 motor;

[0043] 10 battery monomer, 20 box body;

[0044] 1 shell, 11 shell body, 111 bottom wall, 112 first side wall, 113 second side wall, 12 cover plate, 13 pressure relief hole, 14 protective sheet, 15 exhaust groove, 2 electrode assembly, 3 pressure relief mechanism, 31 valve body, 32 first groove, 32a first sub-groove, 32b second sub-groove, 321 first groove segment, 322 second groove segment, 33 second groove, 34 third groove;

[0045] X first direction, Y second direction, Z third direction. DETAILED DESCRIPTION

[0046] The embodiments of the technical solutions of the present application will be described in detail below in conjunction with the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application. ​​​​

[0047] It should be noted that the technical terms or scientific terms used in the embodiments of the present application should be understood as the general meaning understood by the skilled in the art to which the embodiments of the present application belong, unless otherwise specified.

[0048] In the description of the embodiments of the present application, the orientations or positional relationships indicated by the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and are not intended to 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 limiting the embodiments of the present application.

[0049] In addition, the technical terms "first", "second" and the like are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly specified and limited.

[0050] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, 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 those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0051] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be that the first feature is directly above or 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 can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0052] At present, from the development of market situation, the application of power battery is more and more extensive. Power battery is not only applied to energy storage power supply system of water power, fire power, wind power and solar power station, but also widely applied to electric vehicles such as electric bicycle, electric motorcycle, electric vehicle and electric traffic tools, military equipment and aerospace and other fields. With the continuous expansion of the application field of power battery, the demand of its market is also increasing.

[0053] Generally, the battery includes a shell and a pressure relief mechanism arranged on the shell, the pressure relief mechanism includes a valve body and a groove arranged on the valve body, when the pressure of the battery rises to a threshold value, the groove will be broken, so that the valve body is opened by single side flipping along the groove and forms a pressure relief space, so as to realize the release of the gas in the battery, release the pressure in the battery and reduce the risk of battery explosion. However, in the actual pressure relief process, after the valve body is opened by single side flipping, the valve body will shield the high-temperature gas sprayed from one side, causing the high-temperature gas and flame in the battery monomer to be sprayed to the other side and heat to the adjacent battery monomer, causing heat diffusion.

[0054] Based on the above consideration, in order to reduce the risk of heat diffusion, the embodiment of the present application provides a new battery monomer. By arranging a first groove on the valve body in pairs and connecting the two ends of the second groove with the first groove, the valve body can be flipped and opened from both sides at the same time, reducing the risk of high-temperature gas spraying bias.

[0055] The technical scheme described in the embodiment of the present application is applicable to the battery device 100 and the electric device using the battery device 100.

[0056] The electric device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy and an electric tool, etc. The vehicle can be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile or a range extended automobile, etc.; the spacecraft includes an airplane, a rocket, a space shuttle and a spacecraft, etc.; the electric toy includes a fixed or mobile electric toy, for example, a game machine, an electric automobile toy, an electric ship toy and an electric airplane toy, etc.; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembling electric tool and a railway electric tool, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator and an electric planer, etc. The embodiment of the present application does not specially limit the above electric device.

[0057] It should be understood that the technical scheme described in the embodiment of the present application is applicable to all battery devices 100 and electric devices using batteries, but for the sake of simplicity of description, the following embodiments are described taking an electric vehicle as an example.

[0058] Please refer to Figure 1 ,Figure 1 A structural schematic diagram of a vehicle is provided for some embodiments of the present application.

[0059] The vehicle is provided with a battery device 100, which can be arranged at the bottom, head or tail of the vehicle. The battery device 100 can be used for power supply of the vehicle, for example, the battery device 100 can be used as the operating power source of the vehicle. The vehicle can further include a controller 200 and a motor 300, the controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the power demand of the vehicle during starting, navigation and driving.

[0060] Please refer to Figure 2 , Figure 2 An exploded schematic diagram of the battery device 100 is provided for some embodiments of the present application.

[0061] The battery device 100 mentioned in the embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of battery cells 10 connected in series, parallel or mixed connection through bus components. The battery cell assembly can be a battery module, which is formed by arranging and fixing a plurality of battery cells 10 into an independent module.

[0062] In some embodiments, the battery device 100 can be a battery pack, which includes a box 20 and one or more battery cell assemblies accommodated in the box 20 for packaging one or more battery cells 10 to avoid the influence of liquid or other foreign matters on the charging or discharging of the battery cells 10.

[0063] In the embodiments of the present application, the battery cell 10 can be a secondary battery, which refers to a battery cell 10 that can be activated by charging after discharging.

[0064] The battery cell 10 can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead-acid battery, etc., which are not limited in the embodiments of the present application.

[0065] Please refer to Figure 3 and Figure 4 , Figure 3 An exploded view of the battery cell 10 is shown, Figure 4 A front view of the pressure relief mechanism 3 is shown.

[0066] The battery cell 10 in the embodiments of the present application comprises a shell 1, an electrode assembly 2 and a pressure relief mechanism 3. The shell 1 has a receiving cavity, the electrode assembly 2 is arranged in the receiving cavity, and the pressure relief mechanism 3 is arranged on the shell 1. The pressure relief mechanism 3 comprises a valve body 31 and a first groove 32 and a second groove 33 arranged on the valve body 31. The first grooves 32 arranged in pairs extend along a first direction X and are spaced apart from each other along a second direction Y. The pressure relief space is formed between the first grooves 32, and the size of the pressure relief space along the first direction X is greater than the size of the pressure relief space along the second direction Y. The second groove 33 is connected to the first grooves 32 on both sides along the second direction Y, and the second direction Y intersects the first direction X.

[0067] The pressure relief mechanism 3 in the embodiments of the present application is arranged by arranging the second groove 33 between the first grooves 32 arranged in pairs. When the pressure inside the battery cell 10 rises to a threshold value, the valve body 31 can be separated from the shell 1 in the second groove 33 and divided into two sub-valve bodies 31. Each sub-valve body 31 is flipped open along the first groove 32 from both sides of the pressure relief space, so that the high-temperature gas in the battery cell 10 can be sprayed in a direction perpendicular to the shell 1, reducing the risk of high-temperature gas spray bias.

[0068] In addition, the size of the pressure relief space along the first direction X refers to the extension distance of the first groove 32 along the first direction X, and the size of the pressure relief space along the second direction Y refers to the spacing of the first grooves 32 arranged in pairs along the second direction Y.

[0069] By making the size of the pressure relief space along the first direction X greater than the size of the pressure relief space along the second direction Y, and arranging the second groove 33 to extend along the second direction Y, the size of the second groove 33 can be reduced, and the risk of cracking of the second groove 33 before the spray valve can be reduced. At the same time, the distance between the second groove 33 and the flipping shaft can be increased, that is, the force arm of flipping is increased, so that it is easier to flip under the same force, and the valve body 31 is more convenient to flip open after the spray valve. At the same time, the whole pressure relief mechanism 3 is more thoroughly opened, thereby further reducing the risk of high-temperature gas spray bias and improving the reliability of the pressure relief of the battery cell 10.

[0070] Please refer to Figures 3 to 6 , Figure 5 and Figure 6 respectively show the structural schematic diagrams of the battery cell 10 at different angles provided by some embodiments of the present application.

[0071] In some optional embodiments, the shell 1 comprises a shell body 11 and a cover plate 12. The shell body 11 has an opening, and the cover plate 12 is arranged on the opening and connected with the shell body 11. At least one of the shell body 11 and the cover plate 12 is provided with the pressure relief mechanism 3.

[0072] The shell 11 is a component for cooperating with the cover plate 12 to form an internal environment of the battery cell 10, wherein the formed internal environment can be used to accommodate the electrode assembly 2, the electrolyte and other components. The shell 11 and the cover plate 12 can be independent components, the shell 11 encloses to form an accommodating cavity with an opening along the third direction Z, and the cover plate 12 covers the opening and isolates the internal environment of the battery cell 10 from the external environment. Among them, the third direction Z is the height direction of the battery cell 10.

[0073] Optionally, the pressure relief mechanism 3 is arranged on at least one of the shell 11 and the cover plate 12, which means that the pressure relief mechanism 3 can be arranged only on the shell 11, only on the cover plate 12, or on both the shell 11 and the cover plate 12.

[0074] When the pressure relief mechanism 3 is arranged on the shell 11, it can be arranged on the bottom wall 111 of the shell 11 or on the side wall of the shell 11. When the pressure relief mechanism 3 is arranged on the cover plate 12, since the shell 1 can be provided with an opening at one end along the third direction Z, or can be provided with an opening at both ends along the third direction Z, when both ends of the shell 1 are provided with the cover plate 12, the pressure relief mechanism 3 can be arranged on the cover plate 12 on one side or on both sides. The position of the pressure relief mechanism 3 on the shell 11 or the cover plate 12 can be adjusted according to actual needs, as long as it can meet the pressure relief requirements of the battery.

[0075] In some optional embodiments, the shell 11 includes a bottom wall 111 and a plurality of side walls, the bottom wall 111 and the plurality of side walls enclose to form an accommodating cavity with an opening, and the pressure relief mechanism 3 is arranged on the bottom wall 111 and / or the cover plate 12.

[0076] By arranging the pressure relief mechanism 3 on the bottom wall 111 and / or the cover plate 12, the influence of the high-temperature gas in the battery cell 10 on other battery cells 10 after being sprayed vertically to the shell 1 can be reduced, and the risk of heat diffusion can be reduced.

[0077] Optionally, the battery cell 10 can be a cylindrical battery cell 10, a prismatic battery cell 10, a soft-pack battery cell 10 or other shaped battery cell 10, and the prismatic battery cell 10 includes a square battery cell 10, a blade-shaped battery cell 10, a multi-prismatic battery cell, such as a hexagonal battery cell, etc.

[0078] In some embodiments, the plurality of side walls includes a pair of first side walls 112 and a pair of second side walls 113, the area of the first side wall 112 is greater than that of the second side wall 113, the first direction X is parallel to the arrangement direction of the second side wall 113, and the second direction Y is parallel to the arrangement direction of the first side wall 112.

[0079] At this time, the first direction X is the length direction of the battery monomer 10, and the second direction Y is the width direction of the battery monomer 10.

[0080] When the pressure relief mechanism 3 is arranged on the bottom wall 111 and / or the cover plate 12, the second groove 33 can be arranged in the width direction of the battery monomer 10. Since the expansion deformation amount of the first side wall 112 is greater than that of the second side wall 113 during charging and discharging of the battery monomer 10, the above arrangement can reduce the risk of rupture of the second groove 33 due to expansion during charging and discharging of the battery monomer 10, and improve the reliability of the pressure relief mechanism 3.

[0081] It can be understood that in other embodiments, the plurality of side walls include a pair of first side walls 112 and a pair of second side walls 113, the area of the first side wall 112 is greater than that of the second side wall 113, the first direction X is parallel to the arrangement direction of the first side wall 112, and the second direction Y is parallel to the arrangement direction of the second side wall 113.

[0082] At this time, the first direction X is the width direction of the battery monomer 10, and the second direction Y is the length direction of the battery monomer 10.

[0083] When the pressure relief mechanism 3 is arranged on the bottom wall 111 and / or the cover plate 12, the second groove 33 is arranged in the length direction of the battery monomer 10. Therefore, when the valve body 31 is opened, it can be flipped open in the width direction of the battery monomer 10 to the two sides, so that the valve body 31 can be used to shield the high-temperature gas discharged from the pressure relief space on the first side wall 112, i.e., the large side of the battery monomer 10, and can play a protective role to reduce the influence of the high-temperature gas on the adjacent battery monomer 10.

[0084] Please refer to Figures 3 to 6 , and the specific structure of the pressure relief mechanism 3 will be described in detail below.

[0085] For ease of description, the pair of first grooves 32 are defined as a first sub-groove 32a and a second sub-groove 32b, and the two ends of the second groove 33 are connected with the first sub-groove 32a and the second sub-groove 32b, respectively. When the internal pressure of the battery monomer 10 rises to a threshold value, the valve body 31 will be separated from the shell 1 in the second groove 33 and divided into two sub-valve bodies 31. One side of the sub-valve body 31 is flipped open by the second groove 33 through one side area of the first sub-groove 32a and the second sub-groove 32b, and the other side of the sub-valve body 31 is flipped open by the second groove 33 through the other side area of the first sub-groove 32a and the second sub-groove 32b, so that the door opening can be relieved from both sides of the pressure relief space, and the bias risk is reduced.

[0086] In some alternative embodiments, the first grooves 32 are symmetrically arranged relative to the pressure relief space, and the two ends of the second groove 33 are connected to the middle portions of the first grooves 32 in the second direction Y.

[0087] That is, the first sub-groove 32a and the second sub-groove 32b are symmetrically arranged relative to the pressure relief space, one end of the second groove 33 is connected to the middle portion of the first sub-groove 32a, and the other end is connected to the middle portion of the second sub-groove 32b, so that the valve body 31 can be synchronously flipped open from both sides. At the same time, the first sub-groove 32a and the second sub-groove 32b are always subjected to balanced internal pressure during the use cycle of the battery cell 10, so that the pressure relief mechanism 3 will not cause performance degradation of the pressure relief mechanism 3 under long-period stress.

[0088] In some alternative embodiments, the first groove 32 includes a first groove segment 321 and a second groove segment 322 arranged in intersection, the first groove segment 321 is arranged in extension along the first direction X, and the second groove segment 322 is arranged opposite to the two ends of the first groove segment 321 along the first direction X. In the pair of first grooves 32, the second groove segments 322 of the two are arranged in extension towards each other by a certain distance along the second direction Y and the end portions thereof are arranged in interval relative to each other.

[0089] That is, the first sub-groove 32a and the second sub-groove 32b each include a first groove segment 321 and a second groove segment 322, and the second groove segments 322 of the first sub-groove 32a and the second sub-groove 32b are arranged in extension towards each other, so as to increase the breaking length of the pressure relief mechanism 3, and to facilitate flipping open from both sides of the pressure relief space and improve the reliability of flipping open. By arranging the end portions of the second groove segments 322 of the first sub-groove 32a and the second sub-groove 32b in interval relative to each other, the risk of the whole valve body 31 flying out to cause secondary accidents during jetting can be reduced, and the reliability of the pressure relief mechanism 3 can be improved.

[0090] Optionally, for the first sub-groove 32a and / or the second sub-groove 32b, the first groove segment 321 can be arranged in linear extension, and the second groove segment 322 can be arranged in curved extension, so as to play a guiding role and not to cause stress concentration between the first groove segment 321 and the second groove segment 322, and to improve the reliability of tearing.

[0091] Please refer to Figures 3 to 10 , Figure 7 the cross-sectional view of the battery cell 10 provided by some embodiments of the present application is shown, Figure 8 the enlarged view of A in Figure 7 is shown, Figure 9 the cross-sectional view of E-E direction in Figure 7 is shown, Figure 10 the enlarged view of B in Figure 9 is shown.

[0092] In some alternative embodiments, the ratio of the depth of the first groove 32 to the depth of the second groove 33 is 0.8-1.2.

[0093] The depth of the first groove 32 refers to the depth T1 of the inward recess from the surface of the valve body 31, and the depth of the second groove 33 refers to the depth T2 of the inward recess from the surface of the valve body 31. The ratio of the depth T1 of the first groove 32 to the depth T2 of the second groove 33 is 0.8-1.2.

[0094] By making the ratio of the depth T1 of the first groove 32 to the depth T2 of the second groove 33 greater than or equal to 0.8, the valve body 31 can be smoothly flipped open along the first groove 32 after the second groove 33 is broken. By making the ratio of the depth T1 of the first groove 32 to the depth T2 of the second groove 33 less than or equal to 1.2, the risk of the first groove 32 being broken first can be reduced, so that the second groove 33 to the first groove 32 can be sequentially broken in the spray valve, and the valve body 31 can be flipped open.

[0095] Alternatively, the cross section of the first groove 32 and / or the second groove 33 along the extension direction thereof can be provided as an inverted trapezoid or an inverted triangle, etc. The first groove 32 and / or the second groove 33 can be formed by stamping or numerical control machining, so that the groove wall can be smoother, and the blasting pressure can be controlled by controlling the stamping depth, so that when the internal pressure of the battery cell reaches the threshold value, the shell 1 is preferentially broken from the position of the pressure relief mechanism 3, and will not be broken from other positions.

[0096] Alternatively, the depth T1 of the first groove 32 is equal to the depth T2 of the second groove 33, so as to facilitate design and manufacturing.

[0097] Please refer to Figures 3 to 11 , Figure 11 An enlarged view of C in FIG. 1 is shown. Figure 7

[0098] In some alternative embodiments, the pressure relief mechanism 3 further comprises a third groove 34, the third groove 34 is oppositely arranged along the first direction X, and one end of the third groove 34 is connected to one end of the pair of first grooves 32 along the second direction Y, and the other end of the third groove 34 is connected to the other end of the pair of first grooves 32 along the second direction Y. The depth of the third groove 34 is less than the depth of the first groove 32.

[0099] ​Specifically, one of the third grooves 34 is connected to one end of the first sub-groove 32a and the second sub-groove 32b, and the other of the third grooves 34 is connected to the other end of the first sub-groove 32a and the second sub-groove 32b, so that the pressure relief space is formed by the first grooves 32 and the third grooves 34 together. By making the depth T3 of the third grooves 34 less than the depth T1 of the first grooves 32, when the valve body 31 is flipped open on both sides, the third grooves 34 remain connected, which can act as a flipping shaft, so that the flipping of the pressure relief mechanism 3 is more convenient and the flipping difficulty is reduced.

[0100] Optionally, the third grooves 34 can be arranged to extend along an arc-shaped track, and the first grooves 32 and the third grooves 34 can form a racetrack type mechanism. When the pairs of first grooves 32 are symmetrical with respect to the pressure relief space, the pairs of third grooves 34 can also be arranged to be symmetrical with respect to the pressure relief space, so that the reliability of the flipping of the valve body 31 on both sides can be improved, and the risk of high-temperature gas ejection bias is further reduced.

[0101] In some optional embodiments, the ratio of the size W1 of the third grooves 34 along the second direction Y to the size W2 of the pressure relief space along the second direction Y is 0.1-0.5.

[0102] By making the ratio of the size W1 of the third grooves 34 along the second direction Y to the size W2 of the pressure relief space along the second direction Y greater than or equal to 0.1, the strength of the connection can be improved and the cracking risk can be reduced when the valve body 31 is flipped open on both sides. By making the ratio of the size W1 of the third grooves 34 along the second direction Y to the size W2 of the pressure relief space along the second direction Y less than or equal to 0.5, the flipping of the valve body 31 can be facilitated and the reliability of pressure relief can be improved.

[0103] Please refer to Figures 3 to 12 , Figure 12 The enlarged view of C in FIG. 4 is shown. Figure 7

[0104] In some optional embodiments, the shell 1 includes a pressure relief hole 13 and a protective sheet 14, the pressure relief mechanism 3 is arranged in the pressure relief hole 13, and the protective sheet 14 is arranged on the shell 1 and covers the pressure relief hole 13. The shell 1 is provided with an exhaust groove 15 extending to the pressure relief hole 13 and communicating with the pressure relief space.

[0105] The protective sheet 14 has sufficient strength and toughness to protect the pressure relief mechanism 3 from external damage, and the exhaust groove 15 can be arranged as a V-shaped groove so that the air pressure inside and outside the pressure relief hole 13 is balanced. Optionally, a gas leakage detection member can be arranged at the V-shaped groove to detect whether the pressure relief mechanism 3 has a welding quality defect that causes the electrolyte in the battery to leak.

[0106] ​In some optional embodiments, the number of exhaust grooves 15 is multiple, and some of the exhaust grooves 15 are arranged corresponding to the first grooves 32, and some of the exhaust grooves 15 are arranged corresponding to the second grooves 33. By arranging multiple exhaust grooves 15 and arranging the exhaust grooves 15 corresponding to the first grooves 32 and the second grooves 33 respectively, the pressure relief mechanism 3 can be more reliably detected to improve the reliability of the pressure relief mechanism 3.

[0107] Now in the ternary system, especially in the high nickel plus silicon system, it needs to resist the high temperature problem in the thermal runaway process, therefore, the shell 1 needs to use high temperature resistant material.

[0108] In some optional embodiments, the material of at least part of the shell 1 includes one of the following materials: steel, aluminum alloy, and titanium alloy. These materials are resistant to high temperature and have high tensile strength, which can improve the deformation ability of the part of the shell when the battery cell undergoes thermal runaway, so that the shell is not easily damaged and exploded, thereby reducing the risk of thermal runaway of adjacent battery cells, to improve the reliability of the battery.

[0109] Optionally, the material of at least part of the shell 1 includes stainless steel or carbon steel. The type of stainless steel can be SUS304, SUS305, SUS316L, etc., and the type of carbon steel can be SPCC, etc. If the shell 1 adopts stainless steel material, it has high structural strength and can generally meet the requirements of tensile strength under the above high temperature conditions. Moreover, the shell 1 adopts stainless steel material, which is not easy to rust, and can improve the service life of the shell 1 compared with other materials. If the shell 1 adopts carbon steel material, it has high structural strength and can easily meet the requirements of tensile strength under the above high temperature conditions.

[0110] Optionally, when the material of at least part of the shell 1 includes aluminum alloy, the type of aluminum alloy can be AL3003, and when the material of at least part of the shell 1 includes titanium alloy, the type of titanium alloy can be TC1 or TC4, etc.

[0111] In some optional embodiments, the material of at least part of the valve body 31 includes one of the following materials: steel, aluminum alloy, copper-tin-nickel alloy, and titanium alloy.

[0112] Optionally, the material of at least part of the valve body 31 is the same as the material of at least part of the shell 1, which can more conveniently weld the valve body 31 to the shell 1. At the same time, it also makes the shell 1 and the valve body 31 have high melting point, which can also reduce the risk of melting of the shell 1 and the valve body 31 in thermal runaway.

[0113] For example, when the material of at least a partial region of the shell 1 includes a titanium alloy, the material of the valve body 31 can be TC1 or TC4, etc. When the material of at least a partial region of the shell 1 includes an aluminum alloy, the material of the valve body 31 can be MF X2, AL 3003, or AL 1060, etc. When the material of at least a partial region of the shell 1 includes steel, the material of the valve body 31 can be SUS304, SUS305, SUS316L, and SPCC, etc.

[0114] In some optional embodiments, the electrode assembly 2 includes a positive electrode tab including a positive electrode active material capable of reversible deintercalation-intercalation of metal ions, and the positive electrode active material includes a nickel-containing element compound.

[0115] By making the positive electrode active material of the positive electrode tab include a nickel-containing element compound, the energy density and long cycle life of the battery cell can be effectively increased. Although it may also increase the gas generated in the case of thermal runaway of the battery cell 10, by providing the above-mentioned groove structure, reliable discharge of high-temperature gas can also be achieved in the case where the positive electrode active material includes a nickel-containing element compound, thereby improving the reliability of pressure relief.

[0116] Optionally, the electrode assembly 2 further includes a negative electrode tab including a negative electrode active material capable of reversible deintercalation-intercalation of metal ions, and the negative electrode active material includes a silicon-based material.

[0117] Referring to Figures 1 to 12 The battery cell 10 provided by the embodiments of the present application includes a shell 1, an electrode assembly 2, and a pressure relief mechanism 3. The pressure relief mechanism 3 is arranged on the bottom wall 111 of the shell 1, and includes a valve body 31, a first groove 32, a second groove 33, and a third groove 34 arranged on the valve body 31. The first grooves 32 are arranged in pairs and extend along the first direction X and are spaced apart from each other along the second direction Y. The third grooves 34 are respectively connected to the two ends of the first grooves 32 along the second direction Y, and form a pressure relief space together with the first grooves 32. The pressure relief space has a dimension along the first direction X that is greater than a dimension along the second direction Y. The second grooves 33 extend along the second direction Y and are respectively connected to the middle portions of the first grooves 32.

[0118] The battery cell 10 in the embodiments of the present application can separate the valve body 31 from the shell 1 at the second groove 33 and the first groove 32 when the internal pressure of the battery cell 10 rises to a threshold value, and use the third groove 34 as a connecting turning shaft to make the valve body 31 turn to both sides and open, so that the high-temperature gas in the battery cell 10 can be sprayed in a direction perpendicular to the shell 1, reducing the risk of high-temperature gas spray bias. In addition, by making the size of the pressure relief space along the first direction X greater than the size along the second direction Y, and making the second groove 33 extend along the second direction Y, the size of the second groove 33 can be reduced, reducing the risk of cracking of the second groove 33 before the valve, while also increasing the force arm after the valve, making it easier to turn under the same force, improving the reliability of the pressure relief mechanism 3.

[0119] It should be noted that the pressure relief mechanism disclosed in the embodiments of the present application can be used for the battery cell 10 and as a component of the battery cell 10, or can be produced or sold as an independent component. That is, the pressure relief mechanism 3 can be used for all battery devices 100 including the battery cell 10 and the power consumption device including the battery device 100, but is not limited to being used for the battery cell 10, and can also be used for other products to relieve pressure when the internal pressure is greater than a threshold value, and can increase the freedom and operable space for product design.

[0120] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered in the scope of the claims and the specification of the present application. In particular, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, The application relates to a shell with a containing cavity, an electrode assembly arranged in the containing cavity, and a pressure relief mechanism arranged in the shell. The pressure relief mechanism comprises a valve body and first and second grooves arranged on the valve body, the first grooves are arranged in pairs and extend in a first direction and are spaced apart in a second direction, the first grooves form a pressure relief space therebetween, the pressure relief space has a dimension in the first direction greater than a dimension in the second direction, and the second groove is connected to the first grooves on both sides and separates the pressure relief space in the second direction. The first grooves are symmetrically arranged relative to the pressure relief space, and in the second direction, the two ends of the second groove are respectively connected to the middle portions of the first grooves. The first groove comprises a first groove segment and a second groove segment, the first groove segment extends in the first direction, and the second groove segment is oppositely arranged at both ends of the first groove segment in the first direction.

2. The battery cell of claim 1, wherein, In the first grooves arranged in pairs, the second groove segments of the two first grooves extend towards each other by a certain distance in the second direction and are spaced apart at their ends.

3. The battery cell according to claim 1 or 2, characterized in that, The pressure relief mechanism further comprises a third groove. The third grooves are oppositely arranged in the first direction, one is connected to one end of the first grooves arranged in pairs, and the other is connected to the other end of the first grooves arranged in pairs, and the depth of the third groove is less than the depth of the first groove.

4. The battery cell according to any one of claims 1 to 3, characterized in that, The ratio of the dimension of the third groove in the second direction to the dimension of the pressure relief space in the second direction is 0.1-0.

5. The shell comprises a shell body with an opening and a cover plate arranged on the opening and connected to the shell body, and at least one of the shell body and the cover plate is provided with the pressure relief mechanism.

5. The battery cell of claim 4, wherein, The shell body comprises a bottom wall and a plurality of side walls, the bottom wall and the plurality of side walls form a containing cavity with the opening, and the pressure relief mechanism is arranged on the bottom wall and / or the cover plate.

6. The battery cell according to any one of claims 1 to 5, characterized in that, The plurality of side walls comprises first side walls arranged in pairs and second side walls arranged in pairs, and the area of the first side walls is greater than that of the second side walls.

7. The battery cell of claim 6, wherein, The first direction is parallel to the arrangement direction of the second side walls, and the second direction is parallel to the arrangement direction of the first side walls.

8. The battery cell of claim 7, wherein, The plurality of side walls comprises first side walls arranged in pairs and second side walls arranged in pairs, and the area of the first side walls is greater than that of the second side walls. The first direction is parallel to the arrangement direction of the first side walls, and the second direction is parallel to the arrangement direction of the second side walls.

9. The battery cell of claim 7, wherein, The shell comprises a pressure relief hole and a protective sheet, the pressure relief mechanism is arranged in the pressure relief hole, and the protective sheet is arranged on the shell and covers the pressure relief hole. The shell is provided with exhaust grooves, the exhaust grooves extend to the pressure relief hole and are in communication with the pressure relief space.

10. The battery cell of any one of claims 1 to 9, wherein, The number of the exhaust grooves is plural, part of the exhaust grooves correspond to the first grooves, and part of the exhaust grooves correspond to the second grooves. The material of at least part of the shell comprises one of the following materials: steel, aluminum alloy and titanium alloy.

11. The battery cell of claim 10, wherein, ​ 12. The battery cell of any one of claims 1 to 11, wherein, ​ 13. The battery cell of claim 12, wherein, The material of at least a part of the housing comprises stainless steel or carbon steel.

14. The battery cell of any one of claims 1 to 13, wherein, The material of at least a part of the valve body comprises one of steel, aluminum alloy, copper-tin-nickel alloy, and titanium alloy.

15. The battery cell of any one of claims 1 to 14, wherein, The material of at least a part of the valve body is the same as the material of at least a part of the housing.

16. The battery cell of any one of claims 1 to 15, wherein, The electrode assembly comprises a positive electrode tab comprising a positive electrode active material capable of reversible deintercalation-intercalation of metal ions, the positive electrode active material comprising a nickel-containing elemental compound.

17. A pressure relief mechanism characterized by, The valve body and first and second recesses disposed on the valve body; The pairs of first recesses extend in a first direction and are spaced apart in a second direction, a pressure relief space being formed between the first recesses, the pressure relief space having a dimension in the first direction that is greater than a dimension in the second direction, the second recesses being connected to the first recesses on both sides and separating the pressure relief space in the second direction, the second direction intersecting the first direction.

18. A battery device characterized by comprising: A plurality of battery cells according to any one of claims 1-16.

19. An electrical device, comprising: A battery device as claimed in claim 18.

Images