Battery monomer, battery device and electric equipment

Abstract

The utility model discloses a battery monomer, a battery device and electric equipment. The battery monomer comprises a shell, an end cover, an electrode assembly and a pressure relief mechanism, an opening is formed in one side, in the first direction, of the shell, the shell comprises a first wall part and a second wall part which are oppositely arranged in the second direction, and the first direction is perpendicular to the second direction. The end cover is connected to the shell and covers the opening. The electrode assembly is housed within the case. The pressure relief mechanism is arranged on the first wall part, the thickness of the first wall part is larger than that of the second wall part, the connection strength and connection stability between the pressure relief mechanism and the first wall part can be improved, the first wall part is not prone to deformation, and the phenomena that the pressure relief mechanism deforms or is damaged when the first wall part is subjected to internal and external impact are relieved; the risk that the pressure relief mechanism is actuated in advance in the using process is reduced, the service life of the pressure relief mechanism is prolonged, and the reliability of the single battery is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of batteries, and particularly relates to a battery monomer, a battery device, and a power consumption equipment. BACKGROUND

[0002] With the development of new energy technology, batteries are increasingly widely used. For example, batteries are not only applied to energy storage power systems such as hydroelectric, thermal, wind, and solar power stations, but also widely used in electric bicycles, electric motorcycles, electric vehicles, and other electric vehicles, as well as military equipment, aerospace, and other fields.

[0003] The development of battery technology needs to consider various design factors, such as energy density, cycle life, assembly efficiency, processing technology, and the reliability of the battery. CONTENT OF THE INVENTION

[0004] The embodiments of the present application provide a battery monomer, a battery device, and a power consumption equipment, which are beneficial to improve the reliability of the battery monomer.

[0005] According to a first aspect of the present application, the present application provides a battery monomer, which comprises a shell, an end cover, an electrode assembly, and a pressure relief mechanism. The shell has an opening on one side along a first direction, and the shell comprises a first wall portion and a second wall portion oppositely arranged along a second direction, the first direction being perpendicular to the second direction. The end cover is connected to the shell and covers the opening. The electrode assembly is accommodated in the shell. The pressure relief mechanism is arranged on the first wall portion, and the thickness of the first wall portion is greater than the thickness of the second wall portion. The thickness of the first wall portion is relatively large, which is beneficial to improve the connection strength and stability between the pressure relief mechanism and the first wall portion, and the first wall portion is not easy to deform, which is beneficial to alleviate the phenomenon that the pressure relief mechanism is deformed or damaged when the first wall portion is subjected to internal and external impact, reduce the risk of the pressure relief mechanism being actuated in advance during use, prolong the service life of the pressure relief mechanism, and improve the reliability of the battery monomer. The thickness of the second wall portion is relatively small, which is beneficial to reduce the weight of the battery monomer, reduce the occupied space, and improve the energy density of the battery monomer.

[0006] In some embodiments, the shell comprises two third wall portions oppositely arranged along a third direction, each third wall portion connecting the first wall portion and the second wall portion; the area of the third wall portion is greater than the area of the first wall portion and the area of the second wall portion, and the thickness of the third wall portion is less than the thickness of the first wall portion; the first direction, the second direction, and the third direction are perpendicular to each other. Compared with the first wall portion, the third wall portion is more likely to deform, and the third wall portion can release a certain expansion force, which is beneficial to improve the reliability of the battery monomer. The thickness of the third wall portion is relatively thin, which can reduce the occupied space, further reduce the weight of the shell, and improve the energy density of the battery monomer.

[0007] In some embodiments, the third wall portion has a thickness smaller than the thickness of the second wall portion. The third wall portion is more easily deformed than the second wall portion, so as to facilitate the third wall portion to release the expansion force. The second wall portion is relatively less easily deformed, so as to facilitate the strength of the shell to be enhanced and the structural stability of the shell to be improved.

[0008] In some embodiments, the first wall portion is provided with a pressure relief hole penetrating through the first wall portion along the thickness direction of the first wall portion; and the pressure relief mechanism is connected to the first wall portion and blocks the pressure relief hole. The thickness of the first wall portion is relatively large, so as to provide a stable installation and connection basis for the pressure relief mechanism, facilitate the pressure relief mechanism to be connected to the first wall portion by welding or the like, and improve the connection strength and stability between the pressure relief mechanism and the first wall portion.

[0009] In some embodiments, the first wall portion includes a main body portion and a thickened portion, the main body portion is arranged at the outer periphery of the thickened portion, the thickened portion is arranged around the pressure relief hole, and the pressure relief mechanism is connected to the thickened portion. The thickness of the thickened portion is greater than the thickness of the main body portion, and the thickness of the main body portion is greater than the thickness of the second wall portion. The thickness of the thickened portion is greater than the thickness of the main body portion, the pressure relief mechanism is connected to the thickened portion, and the pressure relief mechanism can be provided with a more stable installation and connection basis, so as to further improve the connection strength and stability between the pressure relief mechanism and the first wall portion. The thickness of the main body portion is greater than the thickness of the second wall portion, so as to weaken the deformation degree of the first wall portion as a whole, reduce the risk of deformation or damage of the pressure relief mechanism, prolong the service life of the pressure relief mechanism, and improve the reliability of the battery cell. The thickness of the main body portion is smaller than the thickness of the thickened portion, so as to appropriately reduce the weight of the shell.

[0010] In some embodiments, the main body portion has a first surface facing away from the electrode assembly along the second direction; the thickened portion has a second surface and a third surface, the second surface faces away from the electrode assembly along the second direction, and the third surface faces the electrode assembly along the second direction; along the second direction, the second surface is arranged flush with the first surface, and the third surface protrudes out of the main body portion towards the electrode assembly. In this way, a relatively large gap (for example, the gap between the main body portion and the electrode assembly can be greater than the gap between the thickened portion and the electrode assembly) can be formed between the main body portion and the electrode assembly, which can form part of the exhaust passage, so as to facilitate the gas pressure inside the battery cell to act on the pressure relief mechanism more quickly and smoothly, thereby more effectively relieving pressure.

[0011] In some embodiments, the thickness of the main body portion is greater than or equal to 0.7 mm; and / or, the thickness of the thickened portion is greater than or equal to 1 mm. The thickness of the main body portion is set to be greater than or equal to 0.7 mm in the embodiments of the present application, so as to facilitate the deformation degree of the first wall portion as a whole to be reduced, the service life of the pressure relief mechanism to be prolonged, and the reliability of the battery cell to be improved. The thickness of the thickened portion is set to be greater than or equal to 1 mm in the embodiments of the present application, so as to improve the connection effect and connection strength between the thickened portion and the pressure relief mechanism, and improve the reliability of the battery cell.

[0012] In some embodiments, the pressure relief hole comprises a first hole section and a second hole section arranged along the second direction, the first hole section is arranged at a side of the second hole section close to the electrode assembly, and a projection of the first hole section is located within a projection of the second hole section along the second direction; a size of the first hole section along the second direction is H1, and a size of the second hole section along the second direction is H2, H1 < H2; the pressure relief mechanism is arranged at the second hole section. The depth of the second hole section is greater than the depth of the first hole section, which can provide a larger accommodation space and a larger connection area for the pressure relief mechanism, thereby facilitating the improvement of the connection effect between the pressure relief mechanism and the first wall portion and reducing the risk of poor connection.

[0013] In some embodiments, the pressure relief hole comprises a third hole section arranged at a side of the second hole section away from the first hole section, and a projection of the second hole section is located within a projection of the third hole section along the second direction; the battery monomer comprises a protection member arranged at the third hole section and connected to the first wall portion, and the protection member covers the pressure relief mechanism along the second direction. The stepped surface between the third hole section and the second hole section can support the protection member; the third hole wall of the third hole section can also limit the protection member in a direction perpendicular to the second direction, thereby facilitating the limitation of the relative movement between the protection member and the first wall portion and facilitating the connection operation between the protection member and the first wall portion.

[0014] In some embodiments, the pressure relief hole comprises a fourth hole section, at least part of the fourth hole section is arranged between the second hole section and the third hole section, and a projection of the fourth hole section is located within a projection of the third hole section along the second direction; a size of the third hole section along the second direction is H3, and a size of the fourth hole section along the second direction is H4, H3 < H2, and H4 < H2. The depths of the third hole section and the fourth hole section are both less than the depth of the second hole section, which can reduce the space occupied by the third hole section and the fourth hole section in the second direction, thereby facilitating the increase of the depth of the second hole section without changing the overall thickness of the thickened portion and improving the connection effect between the pressure relief mechanism and the first wall portion.

[0015] In some embodiments, the size of the fourth hole section along the second direction is H4; H1 ≥ 0.2 mm, which facilitates the improvement of the strength of the stepped surface, reduces the risk of fracture of the stepped surface, and improves the support stability; and / or, H2 ≥ 0.5 mm, which can increase the space of the second hole section, increase the connection area between the first wall portion and the pressure relief mechanism, facilitate the improvement of the connection effect between the pressure relief mechanism and the first wall portion, and reduce the risk of poor connection; and / or, H3 ≥ 0.1 mm, which can provide a larger accommodation space for the protection member, reduce the possibility of the protection member protruding from the first wall portion, and facilitate the improvement of the space utilization; and / or, H4 ≥ 0.2 mm, which can provide a larger flipping space for the pressure relief mechanism and facilitate the reduction of the blocking effect of the protection member on the pressure relief mechanism.

[0016] In some embodiments, the battery cell comprises a protection member connected to the first wall portion, the protection member being arranged on the side of the pressure relief mechanism opposite to the electrode assembly and covering the pressure relief mechanism in the second direction; and a gap is formed between the protection member and the pressure relief mechanism. The protection member can cover the pressure relief mechanism in the second direction to separate the pressure relief mechanism from the external environment of the battery cell, thereby providing a safety protection function for the pressure relief mechanism. The gap between the protection member and the pressure relief mechanism can provide a space for the pressure relief mechanism to turn outward, thereby facilitating the smooth turning and pressure relief of the pressure relief mechanism.

[0017] In some embodiments, in the second direction, the protection member does not exceed the surface of the first wall portion opposite to the electrode assembly. The protection member and the first wall portion can share part of the space in the second direction, thereby facilitating the improvement of space utilization, the saving of space, and the improvement of the integrity of the external structure of the shell and the appearance effect.

[0018] According to a second aspect of the present application, the present application further provides a battery device comprising a plurality of battery cells according to any one of the embodiments of the first aspect of the present application.

[0019] According to a third aspect of the present application, the present application further provides a power consuming device comprising a battery device according to any one of the embodiments of the second aspect of the present application, the battery device being configured to provide electric energy. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments of the present application will be briefly introduced as follows. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0021] Figure 1 is a structural schematic diagram of a vehicle provided by some embodiments of the present application.

[0022] Figure 2 is a structural schematic diagram of a battery device provided by some embodiments of the present application.

[0023] Figure 3 is an exploded structural schematic diagram of a battery cell provided by some embodiments of the present application.

[0024] Figure 4 is a structural schematic diagram of a shell of a battery cell provided by some embodiments of the present application.

[0025] Figure 5 is a sectional structural schematic diagram taken along the sectioning line A-A in Figure 4 .

[0026] Figure 6 is a sectional structural schematic diagram taken along the sectioning line A-A in Figure 5An enlarged structural schematic view of the middle region B.

[0027] Figure 7 is Figure 6 An enlarged structural schematic view of the middle region C.

[0028] Figure 8 is a sectional view of a partial structure of an assembled casing, pressure relief mechanism and protection member of a battery cell according to some embodiments of the present application.

[0029] Figure 9 is Figure 8 An enlarged structural schematic view of the middle region D.

[0030] In the drawings:

[0031] Vehicle 1, battery device 2, controller 3, motor 4, box 5, battery cell 6;

[0032] Electrode assembly 10, housing 20, casing 21, first wall portion 211, main body portion 2111, first surface 2111a, thickened portion 2112, second surface 2112a, third surface 2112b, first step surface 2113, second step surface 2114, third step surface 2115, second wall portion 212, third wall portion 213, fourth wall portion 214, pressure relief hole 215, first hole section 2151, first hole wall 2151a, second hole section 2152, second hole wall 2152a, third hole section 2153, third hole wall 2153a, fourth hole section 2154, fourth hole wall 2154a, opening 21a, end cap 22, electrode terminal 30, pressure relief mechanism 40, pressure relief portion 41, weak portion 42, connecting portion 43, protection member 50, first box portion 5a, second box portion 5b, accommodation space 5c;

[0033] First direction X, second direction Y, third direction Z. DETAILED DESCRIPTION

[0034] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0035] Unless otherwise defined, all technical and scientific terms used in the application have the same meanings as those commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the application herein is for the purpose of describing the particular embodiments only and is not intended to be limiting of the application; the use of the terms "including," "comprising," or "having" in the description of the application herein are meant to be inclusive in a manner similar to the term "comprising" to convey "including at least" and additionally can be used in the sense similar to "ad including", "ad comprising", "ad having" or "ad including at least" to convey "including up to and including and any additional one or more of other described or recited elements"; and the use of terms such as "first", "second" and the like in the description of the application herein is not necessarily intended to convey an "ordinal" or "primary secondary" relation among different objects but is intended to distinguish different objects from each other.

[0036] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive or alternative embodiments.

[0037] In the description of the application, it is necessary to explain that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "attaching" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0038] In the application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent the existence of A alone, the existence of A and B together, and the existence of B alone. In addition, the character " / " in the application generally represents an "or" relationship between the front and rear associated objects.

[0039] In the embodiments of the application, the same reference signs represent the same parts, and for the sake of brevity, the detailed description of the same parts is omitted in different embodiments. It should be understood that the thickness, length and width of various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length and width of the integrated device, are only exemplary and should not constitute any limitation on the application.

[0040] "Multiple" appearing in the application means more than two (including two).

[0041] In the embodiments of the application, "parallel" not only includes the case of absolute parallel, but also includes the case of approximate parallel which is generally recognized in engineering; at the same time, "vertical" not only includes the case of absolute vertical, but also includes the case of approximate vertical which is generally recognized in engineering.

[0042] In the embodiments of the present application, the battery cell can be a secondary battery cell, which refers to a battery cell that can be used continuously by activating the active material through charging after discharging.

[0043] The battery cell can be a lithium ion battery cell, a sodium ion battery cell, a sodium lithium ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium sulfur battery cell, a magnesium ion battery cell, a nickel-hydrogen battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc., and the present application is not limited thereto.

[0044] The battery cell generally includes an electrode assembly, a case, and an electrode terminal. The electrode assembly is accommodated in the case, and the electrode terminal is provided in the case. The case is used to package the electrode assembly and components such as electrolyte. The electrode assembly includes a tab, which is electrically connected to the electrode terminal through a relay or directly to the electrode terminal. The electrode terminal can be used to electrically connect the electrode assembly to the circuit outside the battery cell to achieve charging or discharging of the battery cell.

[0045] The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging of the battery cell, active ions (e.g., lithium ions) are inserted and extracted between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, which can prevent the positive and negative electrodes from short-circuiting, and at the same time, allow the active ions to pass through.

[0046] In some embodiments, the positive electrode can be a positive electrode sheet, which can include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0047] In some embodiments, the negative electrode can be a negative electrode sheet, which can include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0048] In some embodiments, the separator is disposed between the positive electrode and the negative electrode.

[0049] In some embodiments, the separator is a separator film. The present application does not have a particular limitation on the type of separator film, and any known porous structure separator film with good chemical stability and mechanical stability can be selected.

[0050] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive electrode and the negative electrode, and at the same time, functions as an ion transport and a separator for the positive and negative electrodes.

[0051] In some embodiments, the electrode assembly is a jelly-roll structure. The positive electrode sheet and the negative electrode sheet are wound into a jelly-roll structure.

[0052] In some embodiments, the electrode assembly is a stacked structure.

[0053] The battery device 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 connected in series, in parallel, or in a mixed connection through a busbar component.

[0054] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells.

[0055] The battery device generally includes a box for packaging one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0056] As an example, the battery cell assembly can be a battery module formed by arranging and fixing a plurality of battery cells into an independent module. As an example, the battery module can be formed by bundling a plurality of battery cells with a cable tie. The battery cell assembly can be accommodated in the box by fixing the battery module in the box. As an example, the box can include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected with the frame, so that a closed space is formed inside the box to accommodate the battery cell assembly.

[0057] In some embodiments, the box can be part of the chassis structure of the vehicle. For example, part of the box can be at least part of the floor of the vehicle, or part of the box can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0058] In some embodiments, the battery device can be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0059] In some embodiments, the battery cell includes a pressure relief mechanism provided in the shell, which has an important influence on the reliability of the battery cell. For example, when a short circuit, overcharge, or the like occurs, thermal runaway may occur inside the battery cell, causing the pressure to rise suddenly. In this case, the internal pressure can be released outward by actuating the pressure relief mechanism to prevent the battery cell from exploding or catching fire.

[0060] The pressure relief mechanism refers to an element or component that is actuated to release the internal pressure when the internal pressure of the battery cell reaches a predetermined threshold. The threshold value is designed differently depending on the design requirements. The threshold value can depend on the material of one or more of the positive plate, the negative plate, the electrolyte, and the separator in the battery cell.

[0061] The pressure relief mechanism can take the form of an explosion-proof valve, a gas valve, a pressure relief valve, or a safety valve, and can specifically take the form of a pressure-sensitive element or structure, i.e., when the internal pressure of the battery cell reaches a predetermined threshold, the pressure relief mechanism performs an action or a weak part provided in the pressure relief mechanism breaks, thereby forming an opening or passage for the internal pressure to be released.

[0062] Alternatively, the pressure relief mechanism can also employ a temperature-sensitive element or configuration, i.e., when the internal temperature of the battery cell reaches a predetermined threshold, the pressure relief mechanism performs an action to form an opening or passage for the internal pressure to be released.

[0063] As referred to in the present application, "actuation" means that the pressure relief mechanism performs an action or is activated to a certain state, so that the internal pressure of the battery cell can be released. The action performed by the pressure relief mechanism can include, but is not limited to, at least one of the following: rupture, breakage, tearing or opening of at least a part of the pressure relief mechanism, etc. When the pressure relief mechanism is actuated, the high-temperature and high-pressure substances inside the battery cell are discharged as exhaust from the actuated part. In this way, the battery cell can be relieved in a controlled pressure manner, thereby avoiding potential more serious accidents.

[0064] As referred to in the present application, the exhaust from the battery cell includes, but is not limited to, the following: electrolyte, dissolved or split positive and negative electrode sheets, fragments of separators, high-temperature and high-pressure gases generated by reactions, flames, etc.

[0065] In the related art, the shell of the battery cell usually includes a housing and an end cover for covering the opening at the top of the housing, and the pressure relief mechanism is arranged in the end cover. Since the overall height of the battery device is increased, the battery device has a multi-layer design inside, and the battery device includes a plurality of battery cells stacked in the vertical direction, and an exhaust space needs to be reserved at the top of each battery cell for the pressure relief mechanism to smoothly relieve pressure. This will waste a lot of space of the battery device, affecting the energy density of the battery device.

[0066] In order to improve the energy density of the battery device, the pressure relief mechanism can be arranged to the side wall of the housing. However, the inventors have realized that the thickness of the side wall of the housing is smaller than that of the end cover, which can affect the connection strength and stability between the pressure relief mechanism and the side wall of the housing, and can also affect the normal pressure relief of the pressure relief mechanism, thereby affecting the reliability of the battery cell.

[0067] In view of this, the embodiments of the present application provide a technical scheme, which arranges the pressure relief mechanism on the side wall of the housing opposite to the end cover, and thickens the thickness of the side wall of the housing where the pressure relief mechanism is arranged. This is beneficial to improve the connection strength and stability between the pressure relief mechanism and the side wall of the housing, and the side wall of the housing is not easy to deform, which is beneficial to alleviate the phenomenon that the pressure relief mechanism is deformed or damaged when the side wall of the housing is subjected to internal and external impact, reduce the risk of premature actuation of the pressure relief mechanism in use, prolong the service life of the pressure relief mechanism, and improve the reliability of the battery cell.

[0068] The technical scheme provided by the embodiments of the present application is applicable to battery devices and electric equipment using battery devices.

[0069] The battery device disclosed by the embodiments of the present application can be used in a power consumption device using the battery device as a power supply or a variety of energy storage systems using the battery device as an energy storage element. The power consumption device can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric automobile, a ship, a spacecraft, etc. Among them, the electric toy can include a fixed or mobile electric toy, such as a game console, an electric automobile toy, an electric ship toy, an electric aircraft toy, etc., and the spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, etc.

[0070] The following embodiments are described by taking a vehicle as an example for convenience of description.

[0071] Figure 1 is a structural schematic diagram of a vehicle provided by some embodiments of the present application. Referring to Figure 1 , the vehicle 1 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 vehicle 1 is internally provided with a battery device 2, which can be arranged at the bottom, the head or the tail of the vehicle 1. The battery device 2 can be used for power supply of the vehicle 1, for example, the battery device 2 can be used as an operating power supply of the vehicle 1. The vehicle 1 can further include a controller 3 and a motor 4, and the controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, to meet the power demand of the vehicle 1 during starting, navigation and driving.

[0072] In some embodiments of the present application, the battery device 2 can not only be used as an operating power supply of the vehicle 1, but also be used as a driving power supply of the vehicle 1, instead of or partially instead of fuel or natural gas to provide driving power for the vehicle 1.

[0073] Figure 2 is an exploded structural schematic diagram of the battery device provided by some embodiments of the present application. Referring to Figure 2The battery device 2 comprises a box 5 and a battery cell 6 accommodated in the box 5. The box 5 is configured to provide an accommodating space 5c for the battery cell 6. The box 5 can have various structures. In some embodiments, the box 5 can comprise a first box part 5a and a second box part 5b. The first box part 5a and the second box part 5b are coupled to each other to define the accommodating space 5c for the battery cell 6. The second box part 5b can be a hollow structure with one open end, and the first box part 5a can be a plate structure. The first box part 5a is coupled to the open end of the second box part 5b to define the accommodating space 5c together with the second box part 5b. Alternatively, the first box part 5a and the second box part 5b can both be hollow structures with one open end. The open end of the first box part 5a is coupled to the open end of the second box part 5b. The box 5 formed by the first box part 5a and the second box part 5b can have various shapes, such as a cylinder or a cuboid.

[0074] To improve the sealing performance of the first box part 5a and the second box part 5b after being coupled, a sealing member, such as a sealing glue or a sealing ring, can be arranged between the first box part 5a and the second box part 5b.

[0075] The first box part 5a can be referred to as an upper box cover, and the second box part 5b can be referred to as a lower box body, when the first box part 5a is coupled to the top of the second box part 5b.

[0076] In the battery device 2, the battery cell 6 can be a plurality of battery cells 6. The plurality of battery cells 6 can be connected in series, in parallel or in a mixed manner. The mixed manner means that the plurality of battery cells 6 are connected in series and in parallel. The plurality of battery cells 6 can be directly connected in series, in parallel or in a mixed manner, and then the plurality of battery cells 6 are accommodated in the box 5. Alternatively, the plurality of battery cells 6 can be connected in series, in parallel or in a mixed manner to form a battery module, and then a plurality of battery modules are connected in series, in parallel or in a mixed manner to form a whole, which is accommodated in the box 5. The battery device 2 can further comprise other structures, for example, the battery device 2 can further comprise a current collecting component for electrically connecting the plurality of battery cells 6.

[0077] The battery cell 6 can be the smallest unit of the battery device 2.

[0078] Figure 3 FIG. 1 is a schematic structural diagram of a battery cell according to some embodiments of the present application. Figure 3 The battery cell 6 comprises a housing 20 and an electrode assembly 10 accommodated in the housing 20.

[0079] The shell 20 is used to encapsulate the electrode assembly 10 and other components such as electrolyte. The shell 20 can be a steel shell, an aluminum shell, a plastic shell (e.g., polypropylene), a composite metal shell (e.g., a copper-aluminum composite shell), or an aluminum-plastic film, etc.

[0080] In some embodiments, the shell 20 is a hollow structure with an internal space for accommodating the electrode assembly 10 and electrolyte. The shape of the shell 20 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 is a cuboid structure, a cuboid shell can be selected.

[0081] The material of the shell 20 can be various, such as metal or plastic. Alternatively, the material of the shell 20 can be copper, iron, aluminum, steel, aluminum alloy, etc. For example, the shell 20 can be a steel shell, an aluminum shell, a plastic shell (e.g., polypropylene), a composite metal shell (e.g., a copper-aluminum composite shell), or an aluminum-plastic film, etc.

[0082] In some embodiments, the shell 20 includes a shell body 21 having an opening 21a and an end cap 22 for covering the opening 21a.

[0083] The shell body 21 is a component for cooperating with the end cap 22 to form an internal cavity of the battery cell 6, which can be used to accommodate the electrode assembly 10, electrolyte, and other components.

[0084] The shell body 21 and the end cap 22 can be independent components. For example, an opening can be provided on the shell body 21, and the end cap 22 is used to cover the opening to form the internal cavity of the battery cell 6.

[0085] The shape of the end cap 22 can be adapted to the shape of the shell body 21 to cooperate with the shell body 21. The material of the end cap 22 can be the same as or different from that of the shell body 21.

[0086] The end cap 22 can be connected to the shell body 21 by welding, bonding, clamping, or other means.

[0087] The shell body 21 can be open at one end or both ends. For example, the shell body 21 is a structure open at one side, and the end cap 22 is provided as one and covers the opening of the shell body 21. As another example, the shell body 21 can also be a structure open at both sides, and the end cap 22 is provided as two and covers the two openings of the shell body 21, respectively.

[0088] In some embodiments, the battery cell 6 further includes an electrode terminal 30, which can be used to electrically connect with the electrode assembly 10 for outputting the electrical energy of the battery cell 6 or inputting the electrical energy to the battery cell 6.

[0089] In some embodiments, the electrode terminal 30 is arranged on the end cover 22. Exemplarily, the shell 21 can also be a structure with two open sides, the battery cell 6 includes two end covers 22 and two electrode terminals 30, the two electrode terminals 30 are respectively arranged on the two end covers 22, and the two electrode terminals 30 are respectively electrically connected to the positive plate and the negative plate.

[0090] Figure 4 is a structural schematic diagram of a shell of a battery cell provided by some embodiments of the present application, Figure 5 is a structural schematic diagram of a shell of a battery cell provided by some embodiments of the present application, Figure 4 is a sectional structural schematic diagram taken along the sectioning line A-A in Figure 6 is a sectional structural schematic diagram taken along the sectioning line B-B in Figure 5 is an enlarged structural schematic diagram of region B in Figure 7 is an enlarged structural schematic diagram of region C in Figure 6 is an enlarged structural schematic diagram of region C in Figure 8 is a sectional structural schematic diagram of a shell of a battery cell provided by some embodiments of the present application, Figure 9 is a sectional structural schematic diagram taken along the sectioning line D-D in Figure 8 is an enlarged structural schematic diagram of region D in

[0091] Referring to Figures 3 to 9 In some embodiments, the battery cell 6 includes a shell 21, an end cover 22, an electrode assembly 10 and a pressure relief mechanism 40. The shell 21 has an opening 21a on one side along a first direction X, the shell 21 includes a first wall portion 211 and a second wall portion 212 oppositely arranged along a second direction Y, and the first direction X is perpendicular to the second direction Y. The end cover 22 is connected to the shell 21 and covers the opening 21a. The electrode assembly 10 is accommodated in the shell 21. The pressure relief mechanism 40 is arranged on the first wall portion 211, and the thickness of the first wall portion 211 is greater than the thickness of the second wall portion 212.

[0092] In some examples, the pressure relief mechanism 40 and the shell 21 can be independently formed members, and the two can be connected by welding, bonding or other means. In alternative embodiments, the pressure relief mechanism 40 and the shell 21 can also be an integrally formed structure, and exemplarily, the pressure relief mechanism 40 is a weak structure formed on the first wall portion 211 for cracking when the battery cell 6 is relieved of pressure.

[0093] The pressure relief mechanism 40 can include a pressure relief portion 41 and a weak portion 42, and the weak portion 42 is arranged along the outer periphery of the pressure relief portion 41. The shape of the weak portion 42 can be various, such as annular, arc-shaped, strip-shaped, etc.

[0094] Optionally, the weak portion 42 can be an annular structure surrounding the pressure relief portion 41.

[0095] The weak portion 42 is the part of the pressure relief mechanism 40 that is easily broken, cracked, torn or opened. Exemplarily, the strength of the weak portion 42 is less than the strength of the pressure relief portion 41.

[0096] The weakened portion 42 can be formed in different ways. In some examples, a predetermined region of the pressure relief mechanism 40 can be thinned, and the thinned portion of the pressure relief mechanism 40 forms the weakened portion 42. In other examples, a predetermined region of the pressure relief mechanism 40 can be treated with a material so that the strength of the region is weaker than that of other regions, and the region is the weakened portion 42.

[0097] The pressure relief portion 41 is used to form a pressure relief passage when the battery cell 6 is in thermal runaway. For example, when the high-temperature and high-pressure substance released by the electrode assembly 10 acts on the weakened portion 42, the weakened portion 42 breaks to at least partially disconnect the pressure relief portion 41 from the housing 21, and the pressure relief portion 41 is flipped or separated from the housing 21 under the impact of the high-temperature and high-pressure substance to form a pressure relief passage on the pressure relief mechanism 40, thereby releasing the internal pressure of the battery cell 6.

[0098] The first direction X can be perpendicular to the thickness direction of the battery cell 6. Alternatively, the first direction X can be the height direction of the battery cell 6.

[0099] The second direction Y can be parallel to the thickness direction of the pressure relief mechanism 40 and perpendicular to the thickness direction of the battery cell 6 and the first direction X. Alternatively, the second direction Y can be the length direction of the battery cell 6.

[0100] The first wall portion 211 and the second wall portion 212 are oppositely arranged along the second direction Y, and both the first wall portion 211 and the second wall portion 212 can be connected to the end cover 22.

[0101] The pressure relief mechanism 40 can be arranged at the center of the first wall portion 211, or can be offset from the center of the first wall portion 211.

[0102] The pressure relief mechanism 40 can be connected to the first wall portion 211, and the connection between the pressure relief mechanism 40 and the first wall portion 211 can include, but is not limited to, welding, bonding, clamping, and the like.

[0103] The thickness of the first wall portion 211 can be uniform or non-uniform. The thickness of the second wall portion 212 can be uniform or non-uniform.

[0104] In the embodiments of the present application, the thickness of the first wall portion 211 refers to the average thickness of the first wall portion 211, and the thickness of the second wall portion 212 refers to the average thickness of the second wall portion 212. The average thickness of the first wall portion 211 is greater than the average thickness of the second wall portion 212. When subjected to the same size impact, the first wall portion 211 is less likely to deform as a whole.

[0105] The first wall portion 211 is not arranged opposite to the opening 21a of the shell 21, and the battery cell 6 can be relieved pressure on one side along the second direction Y, and the plurality of battery cells 6 can be stacked along the first direction X, which is beneficial to improve the flexibility of the stacking direction of the battery cell 6. The pressure relief mechanism 40 is arranged on the first wall portion 211, and the pressure relief mechanism 40 can also be spaced apart from the structure (for example, the electrode terminal 30) on the end cover 22 by a large distance, which is beneficial to reduce the adverse effects of the pressure relief mechanism 40 on the electrode terminal 30 when relieving pressure, and improve the reliability of the battery cell 6.

[0106] The thickness of the first wall portion 211 is relatively large, which is beneficial to improve the connection strength and stability between the pressure relief mechanism 40 and the first wall portion 211, and the first wall portion 211 is not easy to deform, which is beneficial to alleviate the phenomenon that the first wall portion 211 is deformed or damaged when subjected to internal and external impact, reduce the risk of the pressure relief mechanism 40 being actuated in advance during use, prolong the service life of the pressure relief mechanism 40, and improve the reliability of the battery cell 6.

[0107] The thickness of the second wall portion 212 is relatively small, which is beneficial to reduce the weight of the battery cell 6 and the occupied space, and improve the energy density of the battery cell 6.

[0108] In some embodiments, the shell 21 includes two third wall portions 213 arranged opposite along a third direction Z, and each third wall portion 213 connects the first wall portion 211 and the second wall portion 212. The area of the third wall portion 213 is greater than the area of the first wall portion 211 and the area of the second wall portion 212, and the thickness of the third wall portion 213 is less than the thickness of the first wall portion 211. The first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0109] Optionally, the third direction Z can be parallel to the thickness direction of the battery cell 6. The thickness direction of the electrode assembly 10 can be consistent with the thickness direction of the battery cell 6.

[0110] The first wall portion 211, the second wall portion 212 and the third wall portion 213 can all be substantially flat. The first wall portion 211 and the second wall portion 212 are perpendicular to the second direction Y, and the third wall portion 213 is perpendicular to the third direction Z.

[0111] In some examples, the shell 21 further includes a fourth wall portion 214 arranged opposite to the opening 21a along the first direction X, and the fourth wall portion 214 is connected to the first wall portion 211, the second wall portion 212 and the third wall portion 213. The area of the third wall portion 213 can be greater than the area of the fourth wall portion 214.

[0112] Optionally, the third wall portion 213 can be the wall portion with the largest area of the shell 21.

[0113] The electrode assembly 10 will swell during use. The third wall portion 213 has a larger area than the first wall portion 211 and the second wall portion 212, and the swelling of the electrode assembly 10 is more obvious in the third direction Z. The thickness of the third wall portion 213 is set to be smaller than the thickness of the first wall portion 211 in the embodiments. Compared with the first wall portion 211, the third wall portion 213 is more likely to deform, and the third wall portion 213 can release a certain swelling force, which is beneficial to improve the reliability of the battery monomer 6. The thickness of the third wall portion 213 is relatively small, which can reduce the occupied space and further reduce the weight of the shell 21, and improve the energy density of the battery monomer 6.

[0114] In some embodiments, the thickness of the two third wall portions 213 can be substantially the same, and the deformation degree of the two third wall portions 213 is substantially the same. When the electrode assembly 10 swells during use, the two third wall portions 213 can uniformly release the swelling force towards both sides of the third direction Z.

[0115] In some embodiments, the thickness of the third wall portion 213 is smaller than the thickness of the second wall portion 212. Compared with the second wall portion 212, the third wall portion 213 is more likely to deform, which is beneficial to release the swelling force of the third wall portion 213. The second wall portion 212 is relatively not easy to deform, which is beneficial to enhance the strength of the shell 21 and improve the structural stability.

[0116] In some embodiments, the first wall portion 211 is provided with a pressure relief hole 215, and the pressure relief hole 215 penetrates the first wall portion 211 along the thickness direction of the first wall portion 211. The pressure relief mechanism 40 is connected to the first wall portion 211 and blocks the pressure relief hole 215.

[0117] The thickness direction of the first wall portion 211 can be parallel to the second direction Y, and the pressure relief hole 215 penetrates the first wall portion 211 along the second direction Y.

[0118] In the second direction Y, the cross-sectional area of the pressure relief hole 215 can be uniformly set or gradually set, for example, the cross-sectional area of the pressure relief hole 215 can be stepped.

[0119] The shape of the pressure relief hole 215 can be circular, oval, rectangular or other suitable shapes. The shape of the pressure relief mechanism 40 can be substantially matched with the shape of the pressure relief hole 215.

[0120] Optionally, the pressure relief mechanism 40 can be welded to the first wall portion 211 to improve the connection strength between the pressure relief mechanism 40 and the first wall portion 211.

[0121] The first wall portion 211 has a relatively large thickness, which can provide a stable mounting and connecting base for the pressure relief mechanism 40, facilitate the connection of the pressure relief mechanism 40 to the first wall portion 211 by welding or the like, and improve the connection strength and stability between the pressure relief mechanism 40 and the first wall portion 211.

[0122] In some embodiments, the first wall portion 211 includes a main body portion 2111 and a thickened portion 2112, the main body portion 2111 is arranged at the outer periphery of the thickened portion 2112, the thickened portion 2112 is arranged around the pressure relief hole 215, and the pressure relief mechanism 40 is connected to the thickened portion 2112. The thickness of the thickened portion 2112 is greater than the thickness of the main body portion 2111, and the thickness of the main body portion 2111 is greater than the thickness of the second wall portion 212.

[0123] At least part of the main body portion 2111 can be located on both sides of the thickened portion 2112 along the third direction Z and connected to the two third wall portions 213.

[0124] The main body portion 2111 can be connected to the end cover 22 and the fourth wall portion 214.

[0125] In some examples, the two ends of the thickened portion 2112 along the first direction X can be flush with the two ends of the main body portion 2111 along the first direction X, respectively. At this time, the main body portion 2111 includes two parts located on both sides of the thickened portion 2112 along the third direction Z, and the thickened portion 2112 is connected to the two parts of the main body portion 2111 on both sides along the third direction Z, respectively. The two ends of the thickened portion 2112 along the first direction X can be connected to the end cover 22 and the fourth wall portion 214, respectively.

[0126] In other examples, at least one end of the main body portion 2111 along the first direction X extends beyond the thickened portion 2112 along the first direction X. The main body portion 2111 is arranged outside the thickened portion 2112 along the third direction Z and the first direction X. Alternatively, the main body portion 2111 can be arranged around the thickened portion 2112.

[0127] The pressure relief hole 215 penetrates the thickened portion 2112 along the second direction Y. The pressure relief mechanism 40 can be connected to the thickened portion 2112 only, or simultaneously to the thickened portion 2112 and the main body portion 2111.

[0128] Alternatively, the pressure relief mechanism 40 further includes a connecting portion 43 connected to the first wall portion 211. At least part of the connecting portion 43 along the second direction Y has a thickness greater than the thickness of the pressure relief portion 41 and the thickness of the weak portion 42, to further improve the connection strength and stability between the pressure relief mechanism 40 and the first wall portion 211.

[0129] Compared with the main body part 2111, the thickened part 2112 has a greater thickness, and the pressure relief mechanism 40 is connected to the thickened part 2112, which can provide a more stable installation and connection basis for the pressure relief mechanism 40, and is conducive to further improving the connection strength and stability between the pressure relief mechanism 40 and the first wall part 211.

[0130] The thickness of the main body part 2111 is greater than the thickness of the second wall part 212, which can reduce the deformation degree of the first wall part 211 as a whole, reduce the risk of deformation or damage of the pressure relief mechanism 40, and is conducive to prolonging the service life of the pressure relief mechanism 40 and improving the reliability of the battery monomer 6. The thickness of the main body part 2111 is less than the thickness of the thickened part 2112, which can appropriately reduce the weight of the shell 21.

[0131] In some embodiments, the main body part 2111 has a first surface 2111a facing away from the electrode assembly 10 along the second direction Y. The thickened part 2112 has a second surface 2112a and a third surface 2112b, the second surface 2112a faces away from the electrode assembly 10 along the second direction Y, and the third surface 2112b faces the electrode assembly 10 along the second direction Y. Along the second direction Y, the second surface 2112a and the first surface 2111a are arranged flush, and the third surface 2112b exceeds the main body part 2111 in a direction close to the electrode assembly 10.

[0132] The second surface 2112a and the third surface 2112b are oppositely arranged along the second direction Y.

[0133] The first surface 2111a, the second surface 2112a, and the third surface 2112b can all be planes.

[0134] The second surface 2112a and the first surface 2111a are arranged flush, and the thickened part 2112 does not exceed the main body part 2111 in a direction away from the electrode assembly 10, which is conducive to reducing the occupied space.

[0135] The third surface 2112b exceeds the main body part 2111 in a direction close to the electrode assembly 10, that is, the part of the thickened part 2112 that is thickened relative to the main body part 2111 protrudes towards the electrode assembly 10. Therefore, a relatively large gap (for example, the gap between the main body part 2111 and the electrode assembly 10 can be greater than the gap between the thickened part 2112 and the electrode assembly 10) can be formed between the main body part 2111 and the electrode assembly 10, which can form part of the exhaust passage, and is conducive to the gas pressure inside the battery monomer 6 acting on the pressure relief mechanism 40 more quickly and smoothly, thereby more effectively relieving pressure.

[0136] In some embodiments, along the third direction Z, the spacing between the thickened part 2112 and the two third wall parts 213 is equal. The thickened part 2112 can form at least part of the middle region of the first wall part 211 along the third direction Z.

[0137] The main body part 2111 and the electrode assembly 10 can form gaps of substantially the same size on both sides of the thickened part 2112 in the third direction Z, which is conducive to the uniform flow of gas inside the battery monomer 6 and improves the pressure relief effect.

[0138] In some embodiments, the thickness d1 of the main body part 2111 is greater than or equal to 0.7 mm.

[0139] Alternatively, the thickness d1 of the main body part 2111 can be less than or equal to 1.3 mm.

[0140] Alternatively, the thickness d1 of the main body part 2111 can be 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, or 1.3 mm, etc.

[0141] If the thickness of the main body part 2111 is too small, the first wall part 211 as a whole is prone to deformation, which can cause the pressure relief mechanism 40 to deform or be damaged, and thus the phenomenon of premature actuation occurs. The embodiments of the present application set the thickness of the main body part 2111 to be greater than or equal to 0.7 mm, which is conducive to reducing the overall deformation of the first wall part 211, prolonging the service life of the pressure relief mechanism 40, and improving the reliability of the battery monomer 6.

[0142] In some embodiments, the thickness d2 of the thickened part 2112 is greater than or equal to 1 mm.

[0143] Alternatively, the thickness d2 of the thickened part 2112 can be less than or equal to 1.5 mm.

[0144] Alternatively, the thickness d2 of the thickened part 2112 can be 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.5 mm, etc.

[0145] If the thickness of the thickened part 2112 is too small, it can affect the connection effect between the thickened part 2112 and the pressure relief mechanism 40, for example, the thickened part 2112 and the pressure relief mechanism 40 can have welding defects such as welding through. The embodiments of the present application set the thickness of the thickened part 2112 to be greater than or equal to 1 mm, which can improve the connection effect and connection strength between the thickened part 2112 and the pressure relief mechanism 40, and improve the reliability of the battery monomer 6.

[0146] In some embodiments, the pressure relief hole 215 comprises a first hole section 2151 and a second hole section 2152 arranged along the second direction Y, the first hole section 2151 is arranged at a side of the second hole section 2152 close to the electrode assembly 10, and a projection of the first hole section 2151 is within a projection of the second hole section 2152 along the second direction Y. The first hole section 2151 has a size of H1 and the second hole section 2152 has a size of H2 along the second direction Y, and H1 < H2. The pressure relief mechanism 40 is arranged at the second hole section 2152.

[0147] In some examples, the first hole section 2151 and the second hole section 2152 can be arranged adjacently along the second direction Y without other hole sections arranged between the first hole section 2151 and the second hole section 2152. In other examples, the first hole section 2151 and the second hole section 2152 can be arranged spacedly along the second direction Y with other hole sections arranged between the first hole section 2151 and the second hole section 2152.

[0148] The second hole section 2152 has an area greater than that of the first hole section 2151. The second hole section 2152 can cover the first hole section 2151 along the second direction Y. At least one step surface is formed between the first hole section 2151 and the second hole section 2152.

[0149] Optionally, the first hole section 2151 has a first hole wall 2151a and the second hole section 2152 has a second hole wall 2152a, and the first hole wall 2151a and the second hole wall 2152a can be connected by a first step surface 2113.

[0150] The pressure relief mechanism 40 can be wholly accommodated in the second hole section 2152, or can be partially accommodated in the second hole section 2152 with a part of the pressure relief mechanism 40 protruding out of the second hole section 2152 away from the first hole section 2151.

[0151] The pressure relief mechanism 40 can be supported on the first step surface 2113. The pressure relief mechanism 40 can be connected to the first step surface 2113 and / or the second hole wall 2152a by welding, bonding or other suitable means.

[0152] The step surface formed between the first hole section 2151 and the second hole section 2152 can support the pressure relief mechanism 40; the second hole wall 2152a of the second hole section 2152 can also limit the pressure relief mechanism 40 in a direction perpendicular to the second direction Y, which is conducive to limiting the relative movement between the pressure relief mechanism 40 and the first wall portion 211 and facilitating the connection operation between the pressure relief mechanism 40 and the first wall portion 211.

[0153] The size H1 of the first hole section 2151 along the second direction Y can be the depth of the first hole section 2151, and the size H2 of the second hole section 2152 along the second direction Y can be the depth of the second hole section 2152. The depth of the second hole section 2152 is greater than the depth of the first hole section 2151, which can provide a larger accommodation space and a larger connection area for the pressure relief mechanism 40, thereby improving the connection effect between the pressure relief mechanism 40 and the first wall portion 211 and reducing the risk of poor connection.

[0154] In some embodiments, H1≥0.2mm. In this way, the strength of the stepped surface can be improved, the risk of the stepped surface breaking can be reduced, and the support stability can be improved.

[0155] Alternatively, H1 can be 0.2mm, 0.3mm, or 0.4mm, etc.

[0156] In some embodiments, H2≥0.5mm. In this way, the space of the second hole section 2152 can be increased, the connection area between the first wall portion 211 and the pressure relief mechanism 40 can be increased, and the connection effect between the pressure relief mechanism 40 and the first wall portion 211 can be improved, thereby reducing the risk of poor connection.

[0157] Alternatively, H2 can be 0.5mm, 0.6mm, or 0.7mm, etc.

[0158] In some embodiments, the pressure relief hole 215 includes a third hole section 2153, which is arranged on the side of the second hole section 2152 away from the first hole section 2151 along the second direction Y, and the projection of the second hole section 2152 is located within the projection of the third hole section 2153. The battery monomer 6 includes a protective piece 50, which is arranged in the third hole section 2153 and connected to the first wall portion 211, and the protective piece 50 covers the pressure relief mechanism 40 along the second direction Y.

[0159] In some examples, the third hole section 2153 and the second hole section 2152 can be arranged adjacent to each other along the second direction Y, and no other hole section is arranged between the third hole section 2153 and the second hole section 2152. In other examples, the third hole section 2153 and the second hole section 2152 can be arranged apart from each other along the second direction Y, and other hole sections are arranged between the third hole section 2153 and the second hole section 2152.

[0160] The area of the third hole section 2153 is greater than the area of the second hole section 2152. Along the second direction Y, the third hole section 2153 can cover the second hole section 2152. At least one stepped surface is formed between the third hole section 2153 and the second hole section 2152.

[0161] The protective piece 50 can be entirely accommodated in the third hole section 2153, or can be partially accommodated in the third hole section 2153, and a part of the protective piece 50 can protrude out of the third hole section 2153 away from the second hole section 2152.

[0162] The protector 50 can be supported on the stepped surface between the third hole section 2153 and the second hole section 2152. The pressure relief mechanism 40 can be connected to the stepped surface between the third hole section 2153 and the second hole section 2152 by welding, bonding or other suitable means.

[0163] The stepped surface between the third hole section 2153 and the second hole section 2152 can support the protector 50; the third hole wall 2153a of the third hole section 2153 can also limit the protector 50 in a direction perpendicular to the second direction Y, which is conducive to limiting the relative movement of the protector 50 and the first wall portion 211 and facilitating the connection operation between the protector 50 and the first wall portion 211.

[0164] The protector 50 can cover the pressure relief mechanism 40 along the second direction Y to separate the pressure relief mechanism 40 from the external environment of the battery monomer 6, thereby producing a safety protection effect on the pressure relief mechanism 40.

[0165] Optionally, the material of the protector 50 is PET. The structural strength of the protector 50 is relatively low and it can be easily broken by high-temperature and high-pressure substances, which has little effect on the discharge of high-temperature and high-pressure substances.

[0166] In some embodiments, the pressure relief hole 215 includes a fourth hole section 2154, at least part of the fourth hole section 2154 is located between the second hole section 2152 and the third hole section 2153, and the projection of the fourth hole section 2154 is located within the projection of the third hole section 2153 along the second direction Y. The size of the third hole section 2153 along the second direction Y is H3, and the size of the fourth hole section 2154 along the second direction Y is H4, H3

[0167] The fourth hole section 2154 can be located on the side of the second hole section 2152 away from the first hole section 2151 and on the side of the third hole section 2153 facing the second hole section 2152.

[0168] The area of the fourth hole section 2154 is greater than the area of the second hole section 2152 and less than the area of the third hole section 2153.

[0169] The third hole section 2153 has a third hole wall 2153a, the fourth hole section 2154 has a fourth hole wall 2154a, the second hole wall 2152a and the fourth hole wall 2154a are connected by a second stepped surface 2114, and the fourth hole wall 2154a and the third hole wall 2153a are connected by a third stepped surface 2115.

[0170] The fourth hole section 2154 is further provided between the second hole section 2152 and the third hole section 2153, the pressure relief mechanism 40 provided on the second hole section 2152 and the protective piece 50 provided on the third hole section 2153 can be spaced apart through the fourth hole section 2154, the fourth hole section 2154 can provide a space for the pressure relief mechanism 40 to turn outwards, which is conducive to the smooth turning and pressure relief of the pressure relief mechanism 40.

[0171] The size H3 of the third hole section 2153 along the second direction Y can be the depth of the third hole section 2153, the size H4 of the fourth hole section 2154 along the second direction Y can be the depth of the fourth hole section 2154, and the depths of the third hole section 2153 and the fourth hole section 2154 are both less than the depth of the second hole section 2152, which can reduce the space occupied by the third hole section 2153 and the fourth hole section 2154 in the second direction Y, and is conducive to increasing the depth of the second hole section 2152 while the overall thickness of the thickened portion 2112 remains unchanged, and improving the connection effect between the pressure relief mechanism 40 and the first wall portion 211.

[0172] In some embodiments, H3≥0.1mm. In this way, a larger accommodation space can be provided for the protective piece 50, reducing the possibility of the protective piece 50 protruding from the first wall portion 211, and facilitating the improvement of space utilization.

[0173] Optionally, H3 can be 0.1mm, 0.2mm or 0.3mm, etc.

[0174] In some embodiments, H4≥0.2mm. In this way, a larger turning space can be provided for the pressure relief mechanism 40, which is conducive to reducing the blocking effect of the protective piece 50 on the pressure relief mechanism 40.

[0175] Optionally, H4 can be 0.2mm, 0.3mm or 0.4mm, etc.

[0176] In some examples, the battery monomer 6 includes a protective piece 50 connected to the first wall portion 211, the protective piece 50 is provided on the side of the pressure relief mechanism 40 away from the electrode assembly 10 and covers the pressure relief mechanism 40 along the second direction Y. A gap is formed between the protective piece 50 and the pressure relief mechanism 40.

[0177] Optionally, the gap formed between the protective piece 50 and the pressure relief mechanism 40 can be the fourth hole section 2154.

[0178] The protective piece 50 can cover the pressure relief mechanism 40 along the second direction Y to separate the pressure relief mechanism 40 from the external environment of the battery monomer 6, thereby producing a safety protection effect on the pressure relief mechanism 40. The gap between the protective piece 50 and the pressure relief mechanism 40 can provide a space for the pressure relief mechanism 40 to turn outwards, which is conducive to the smooth turning and pressure relief of the pressure relief mechanism 40.

[0179] In some embodiments, the protection member 50 does not protrude beyond the surface of the first wall portion 211 facing away from the electrode assembly 10 along the second direction Y.

[0180] The side of the first wall portion 211 facing away from the electrode assembly 10 can be provided with a recess, and the protection member 50 can be accommodated in the recess.

[0181] Optionally, the recess can be the third hole section 2153.

[0182] The surface of the protection member 50 facing away from the electrode assembly 10 can be flush with the surface of the first wall portion 211 facing away from the electrode assembly 10, or the surface of the protection member 50 facing away from the electrode assembly 10 can be closer to the electrode assembly 10 than the surface of the first wall portion 211 facing away from the electrode assembly 10. The protection member 50 and the first wall portion 211 can share the space along the second direction Y, which is conducive to improving the space utilization, saving space, and improving the integrity of the external structure of the shell 21 and the appearance effect.

[0183] According to some embodiments of the present application, the present application further provides a battery device 2, which comprises a plurality of battery cells 6 provided by any one of the above embodiments.

[0184] In some embodiments, the plurality of battery cells 6 are arranged in a stack along the first direction X. The end cover 22 of one of the adjacent two battery cells 6 and the fourth wall portion 214 of the other battery cell 6 are arranged adjacent to and opposite to each other.

[0185] The battery device 2 provided by the embodiments of the present application comprises a plurality of battery cells 6, and the pressure relief mechanism 40 of the battery cell 6 is arranged on the first wall portion 211 of the shell 21 along the second direction Y. The battery cell 6 releases pressure from one side along the second direction Y, and no exhaust space needs to be reserved between the adjacent two battery cells 6, which is conducive to improving the space utilization along the first direction X and further improving the energy density of the battery device 2.

[0186] According to some embodiments of the present application, the present application further provides a power consumption device, which comprises the battery device 2 provided by any one of the above embodiments, and the battery device 2 is used to provide electric energy.

[0187] The embodiment of the application provides a battery monomer 6, which comprises a shell 21, an end cover 22, an electrode assembly 10 and a pressure relief mechanism 40. The shell 21 has an opening 21a on one side along a first direction X, the shell 21 comprises a first wall part 211 and a second wall part 212 oppositely arranged along a second direction Y and two third wall parts 213 oppositely arranged along a third direction Z, the area of the third wall part 213 is greater than the area of the first wall part 211, the first direction X, the second direction Y and the third direction Z are perpendicular to each other. The end cover 22 is connected to the shell 21 and covers the opening 21a. The electrode assembly 10 is contained in the shell 21. The pressure relief mechanism 40 is welded to the first wall part 211, the thickness of the first wall part 211 is greater than the thickness of the second wall part 212 and the thickness of the third wall part 213. The thickness of the two third wall parts 213 is equal and smaller than the thickness of the second wall part 212. The first wall part 211 is provided with a pressure relief hole 215, the pressure relief hole 215 penetrates the first wall part 211 along the thickness direction of the first wall part 211. The pressure relief mechanism 40 is connected to the first wall part 211 and blocks the pressure relief hole 215. The first wall part 211 comprises a main body part 2111 and a thickened part 2112, the main body part 2111 is arranged at the outer periphery of the thickened part 2112, the thickened part 2112 is arranged around the pressure relief hole 215, and the pressure relief mechanism 40 is connected to the thickened part 2112. The thickness of the thickened part 2112 is greater than the thickness of the main body part 2111, and the thickness of the main body part 2111 is greater than the thickness of the second wall part 212. The pressure relief hole 215 is a multi-layer stepped structure, the pressure relief hole 215 comprises a first hole section 2151, a second hole section 2152, a fourth hole section 2154 and a third hole section 2153 arranged in sequence along the second direction Y, the pressure relief mechanism 40 is arranged at the second hole section 2152, a protection piece 50 is arranged in the third hole section 2153, and the protection piece 50 covers the pressure relief mechanism 40.

[0188] Along the second direction Y, the size H1 of the first hole section 2151 is greater than or equal to 0.2 mm, the size H2 of the second hole section 2152 is greater than or equal to 0.5 mm, the size H3 of the third hole section 2153 is greater than or equal to 0.1 mm, and the size H4 of the fourth hole section 2154 is greater than or equal to 0.2 mm. H2>H1, H2>H3, and H2>H4.

[0189] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced equivalently. Such modifications or replacements do not change the essence of the corresponding technical solutions, which should be covered in the scope of the claims and the specification of the present application. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. 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 battery cell comprises: a housing having an opening on one side in a first direction, the housing comprising a first wall portion and a second wall portion oppositely arranged in a second direction, the first direction being perpendicular to the second direction; a cover connected to the housing and covering the opening; an electrode assembly accommodated in the housing; and a pressure relief mechanism provided on the first wall portion, the first wall portion having a thickness greater than that of the second wall portion.

2. The battery cell according to claim 1, wherein: the housing comprises two third wall portions oppositely arranged in a third direction, each of the third wall portions connecting the first wall portion and the second wall portion; the third wall portions have an area greater than that of the first wall portion and the second wall portion, and a thickness less than that of the first wall portion; the first direction, the second direction and the third direction are perpendicular to each other.

3. The battery cell according to claim 2, wherein: the thickness of the third wall portion is less than that of the second wall portion.

4. The battery cell according to any one of claims 1-3, wherein: the first wall portion is provided with a pressure relief hole penetrating through the first wall portion in the thickness direction of the first wall portion; and the pressure relief mechanism is connected to the first wall portion and seals the pressure relief hole.

5. The battery cell according to claim 4, wherein: the first wall portion comprises a main body portion and a thickened portion, the main body portion being provided at the outer periphery of the thickened portion, the thickened portion being arranged around the pressure relief hole, and the pressure relief mechanism being connected to the thickened portion; the thickened portion has a thickness greater than that of the main body portion, and the main body portion has a thickness greater than that of the second wall portion.

6. The battery cell according to claim 5, wherein: the main body portion has a first surface facing away from the electrode assembly in the second direction; the thickened portion has a second surface and a third surface, the second surface facing away from the electrode assembly in the second direction, and the third surface facing toward the electrode assembly in the second direction; in the second direction, the second surface and the first surface are arranged flush, and the third surface protrudes beyond the main body portion toward the electrode assembly.

7. The battery cell according to claim 5 or 6, wherein: the thickness of the main body portion is greater than or equal to 0.7 mm; and / or the thickness of the thickened portion is greater than or equal to 1 mm.

8. The battery cell according to claim 4, wherein: the pressure relief hole comprises a first hole section and a second hole section arranged in the second direction, the first hole section being provided on the side of the second hole section close to the electrode assembly, and the projection of the first hole section being located within the projection of the second hole section in the second direction; in the second direction, the size of the first hole section is H1, and the size of the second hole section is H2, H1 < H2; the pressure relief mechanism is provided on the second hole section.

9. The battery cell according to claim 8, wherein: The pressure relief hole comprises a third hole section, which is arranged on the side of the second hole section away from the first hole section, and the projection of the second hole section is located within the projection of the third hole section along the second direction; The battery cell comprises a protection member, which is arranged on the third hole section and connected to the first wall portion, and the protection member covers the pressure relief mechanism along the second direction.

10. The battery cell according to claim 9, wherein, The pressure relief hole comprises a fourth hole section, at least part of which is arranged between the second hole section and the third hole section, and the projection of the fourth hole section is located within the projection of the third hole section along the second direction; Along the second direction, the size of the third hole section is H3, and the size of the fourth hole section is H4, H3 < H2, and H4 < H2.

11. The battery cell according to claim 10, wherein, Along the second direction, the size of the fourth hole section is H4; H1 ≥ 0.2 mm, and / or H2 ≥ 0.5 mm, and / or H3 ≥ 0.1 mm, and / or H4 ≥ 0.2 mm.

12. The battery cell according to any one of claims 1-3, 5-6, 8-11, wherein, The battery cell comprises a protection member, which is connected to the first wall portion, arranged on the side of the pressure relief mechanism away from the electrode assembly, and covers the pressure relief mechanism along the second direction; A gap is formed between the protection member and the pressure relief mechanism.

13. The battery cell according to claim 12, wherein, Along the second direction, the protection member does not exceed the surface of the first wall portion away from the electrode assembly.

14. A battery device characterized by comprising: A plurality of battery cells according to any one of claims 1-13 are included.

15. An electrical device, characterized by The battery device according to claim 14 is used to provide electrical energy.

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