Battery monomer, battery, power utilization device and battery monomer production method

Abstract

The embodiment of the invention provides a battery monomer, a battery, a power utilization device and a battery monomer production method. The battery monomer comprises a shell, an electrode assembly, a ventilation valve assembly and a protection piece, the shell is provided with a containing cavity and comprises a first wall, the first wall is provided with a first surface and a second surface which are opposite, the second surface faces the outside of the battery monomer, the first wall is provided with a first exhaust hole, and the first exhaust hole penetrates through the first surface and the second surface; the electrode assembly is accommodated in the accommodating cavity; the ventilation valve assembly is connected to the first wall and covers the first exhaust hole; the protection piece is detachably connected to the second surface and covers the ventilation valve assembly. The detachable protection piece is arranged to protect the ventilation valve assembly, so that the possibility that foreign matters and impurities enter the ventilation valve assembly to influence the exhaust function in the production process of the battery monomer is reduced, and the reliability of the ventilation valve assembly is improved.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and more particularly, to a battery cell, a battery, an electrical device, and a method for manufacturing a battery cell. Background Art

[0002] Battery cells are widely used in electronic devices, such as mobile phones, laptop computers, battery cars, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools, etc.

[0003] In order to reduce the internal air pressure of the battery cell, a breathing valve assembly is provided on some battery cells. However, during the production process of the battery cell, foreign impurities easily enter the breathing valve assembly, affecting the exhaust function of the breathing valve assembly and even damaging the breathing valve assembly. Summary of the Invention

[0004] The present application provides a battery cell, a battery, an electrical device, and a method for manufacturing a battery cell, which can reduce the risk of damage to the breathing valve assembly on the battery cell.

[0005] In a first aspect, an embodiment of the present application provides a battery cell, including: a housing having a receiving cavity, the housing including a first wall having opposite first and second surfaces, the second surface facing the outside of the battery cell, the first wall being provided with a first exhaust hole that penetrates through the first and second surfaces; an electrode assembly received in the receiving cavity; a breathing valve assembly connected to the first wall and covering the first exhaust hole; and a protection member removably connected to the second surface and covering the breathing valve assembly. By providing a removable protection member to protect the second exhaust hole, the possibility of foreign impurities entering the breathing valve assembly during the production process of the battery cell and affecting its exhaust function is reduced, and the reliability of the breathing valve assembly is improved.

[0006] In some embodiments, the protection member is adhesively bonded, snap-connected, or connected through a connecting member to the second surface, and the connecting member is removably connected to the first wall and the protection member respectively. The removable connection of the protection member to the second surface is achieved through adhesion, snap connection, or a connecting member, with a simple structure and convenient disassembly and assembly operations.

[0007] In some embodiments, the protection member is adhesively bonded to the second surface, and the protection member includes a protective layer and an adhesive layer, and the adhesive layer is connected to the side of the protective layer facing the second surface and adhesively bonded to the second surface. Bonding the protection member to the second surface facilitates the installation and removal of the protection member.

[0008] In some embodiments, the adhesive layer is disposed around the first vent hole. The adhesive layer is disposed around the first vent hole, and the adhesive layer and the protective layer enclose a relatively closed space, which can better protect the first vent hole and further reduce the possibility of foreign matter and impurities entering the first vent hole during the production process of the battery cell.

[0009] In some embodiments, the protective layer includes a body and an extension ear, the body is connected to the second surface, and the extension ear is connected to the edge of the body and has a gap with the second surface. By providing the extension ear, when removing the protective member, the operator or the operating instrument can clamp the extension ear to directly tear off the protective member, thereby improving the removal efficiency of the protective member.

[0010] In some embodiments, the size of the gap in the first direction gradually increases from the end of the extension ear connected to the body to the end of the extension ear away from the body. By designing the size of the gap between the extension ear and the second surface to gradually increase in the first direction, the extension ear forms a tilted structure, which is more convenient for the operator or operating equipment to clamp the extension ear, and further improves the removal efficiency of the protective member.

[0011] In some embodiments, the protective member is provided with a through hole, and the through hole penetrates the protective member along the first direction. The through hole can be used to connect the first exhaust hole and the breathable valve assembly, so as to detect the working performance of the breathable valve assembly of this embodiment before installing the insulating patch.

[0012] In some embodiments, the maximum dimension of the through hole along the second direction is smaller than the maximum dimension of the first exhaust hole along the second direction, and the second direction is parallel to the first surface and parallel to or intersecting with the extension direction of the first wall. The maximum dimension of the through hole is designed to be smaller than the maximum dimension of the first exhaust hole, thereby reducing the possibility of foreign matter and impurities directly entering the first exhaust hole through the through hole.

[0013] In some embodiments, the maximum dimension of the through hole along the second direction is less than or equal to 1 mm. By designing the maximum dimension of the through hole in the second direction to the above value, the possibility of foreign matter and impurities entering the through hole can be further reduced.

[0014] In some embodiments, the breathable valve assembly includes: a first valve body connected to the first wall and provided with a second exhaust hole that penetrates the first valve body along the first direction and communicates with the first exhaust hole; a breathable membrane layer connected to a side of the first valve body facing away from the first wall and covering the second exhaust hole. Designing the breathable valve assembly to include the first valve body and the breathable membrane layer can not only achieve the function of exhausting gas, but also, under such a structure, the overall size of the exhaust valve in the first direction is relatively small, reducing the impact on other accessory structures of the end cap assembly during installation.

[0015] In some embodiments, the first surface is sequentially provided with a first groove and a second groove that communicate with each other along the first direction. The second groove communicates with the first exhaust hole. In the second direction, the maximum dimension of the first groove is greater than the maximum dimension of the second groove, and the maximum dimension of the second groove is greater than the maximum dimension of the first exhaust hole. The second direction is parallel to the first surface and is parallel or intersects with the extending direction of the first wall; at least a part of the first valve body is installed in the first groove. By providing the first groove and the second groove, the first valve body located in the first groove communicates with the first exhaust hole through the second groove, and the dimensions of the first valve body, the second groove, and the first exhaust hole gradually decrease in the second direction, which is beneficial to the concentrated discharge of gas.

[0016] In some embodiments, the number of the second exhaust holes is multiple. By designing the number of the second exhaust holes to be multiple, it is beneficial to the discharge of gas.

[0017] In some embodiments, one of the multiple second exhaust holes is located in the middle of the first valve body, and the remaining second exhaust holes are arranged around the second exhaust hole located in the middle of the first valve body. Adopting such a structural form can, to a certain extent, increase the layout density of the second exhaust holes and is more conducive to gas entering the second groove from the second exhaust holes.

[0018] In some embodiments, the battery cell further includes an insulating member connected to the first wall. The insulating member is provided with a third exhaust hole. The breathable valve assembly is located between the first wall and the insulating member and communicates with the third exhaust hole. Arranging the breathable valve assembly between the first wall and the insulating member can improve the stability of the breathable valve assembly after installation.

[0019] In some embodiments, the projection of the second exhaust hole on the insulating member along the first direction is located within the third exhaust hole. Such a structure makes the aperture of the fifth exhaust hole greater than or equal to the aperture of the fourth exhaust hole, which is beneficial to the gas in the battery cell entering the breathable valve assembly from the fifth exhaust hole and improves the exhaust efficiency.

[0020] In some embodiments, the battery cell further includes a pressure relief mechanism. The first wall is provided with a fourth exhaust hole, and the pressure relief mechanism seals the fourth exhaust hole. The pressure relief mechanism can be used to discharge gas when the internal pressure of the battery cell is too high, reducing the risk of the battery cell bursting due to excessive internal air pressure.

[0021] In some embodiments, the first wall is the end cover body of the end cover assembly or a wall of the outer shell.

[0022] In a second aspect, an embodiment of the present application further provides a battery, including the battery cell according to any one of the above technical solutions.

[0023] In a third aspect, an embodiment of the present application further provides an electrical device, including the above battery, and the battery is used to provide electrical energy.

[0024] In a fourth aspect, an embodiment of the present application further provides a method for manufacturing a battery cell, including the following steps: covering a protective member at the first exhaust hole of the battery cell, the first exhaust hole communicating with a breathable valve assembly, and the breathable valve assembly being used to exhaust gas from the inside of the battery cell to the outside; tearing off the protective member.

[0025] In some embodiments, before tearing off the protective member, a sealing nail welding process is further included on the battery cell.

[0026] In some embodiments, after tearing off the protective member, an insulating film coating process is further included on the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments of the present application. Obviously, the following described drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to the drawings.

[0028] Figure 1 Structural schematic diagram of a vehicle provided by some embodiments of the present application;

[0029] Figure 2 Structural schematic diagram of a battery provided by some embodiments of the present application;

[0030] Figure 3 Structural schematic diagram of a battery cell provided by some embodiments of the present application;

[0031] Figure 4 Exploded structural schematic diagram of an end cover assembly provided by some embodiments of the present application;

[0032] Figure 5Schematic structural diagram of the end cap assembly provided by some embodiments of the present application;

[0033] Figure 6 For Figure 5 A-A sectional view of;

[0034] Figure 7 Schematic structural diagram of the end cap assembly provided by some embodiments of the present application after removing the protective member;

[0035] Figure 8 For Figure 7 B-B sectional view of;

[0036] Figure 9 Exploded structural diagram of the end cap assembly provided by some embodiments of the present application;

[0037] Figure 10 Schematic structural diagram of the protective member of the battery cell provided by some embodiments of the present application;

[0038] Figure 11 Schematic connection diagram of the protective member of the battery cell and the second surface provided by some embodiments of the present application;

[0039] Figure 12 Schematic structural diagram of the breather valve assembly of the battery cell provided by some embodiments of the present application;

[0040] Figure 13 Flow chart of the battery cell production method provided by some embodiments of the present application.

[0041] Reference numerals in the specific embodiments are as follows:

[0042] 1000, vehicle;

[0043] 100, battery;

[0044] 10, box body; 11, first part; 12, second part;

[0045] 20. Battery cell; 21. End cap assembly; 211. First wall; 2111. First surface; 21111. First groove; 21112. Second groove; 2112. Second surface; 2113. First exhaust hole; 2114. Fourth exhaust hole; 212. Breather valve assembly; 2121. First valve body; 21211. Second exhaust hole; 2122. Breather membrane layer; 213. Protective part; 2131. Protective layer; 21311. Through hole; 21312. Body; 21313. Extension ear; 21314. Gap; 2132. Adhesive layer; 214. Insulating part; 2141. Third exhaust hole; 2142. Exhaust structure; 215. Pressure relief mechanism; 216. Insulating patch; 21a. Electrode terminal; 22. Housing; 221. Opening; 222. Accommodating cavity; 22a. First insulating film layer; 22b. Second insulating film layer; 23. Electrode assembly; 24. Adapter plate;

[0046] 200. Controller;

[0047] 300. Motor;

[0048] X. First direction; Y. Second direction. Detailed implementation manners

[0049] 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 clearly described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0050] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs; the terms used in the description of the present application in the specification are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of the present application or the above drawings are used to distinguish different objects and are not used to describe a specific order or primary-secondary relationship.

[0051] Referring to "embodiments" in the present application means that specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments.

[0052] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "joined", and "attached" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0053] The term "and / or" in the present application is merely an association relationship describing associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects.

[0054] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, in different embodiments, the detailed descriptions of the same components are omitted. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are only for illustrative purposes and should not constitute any limitation to the present application.

[0055] The term "a plurality of" as used in the present application refers to two or more (including two).

[0056] In the present application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, a magnesium-ion battery cell, etc., and the embodiments of the present application do not limit this. The battery cell may be in a cylindrical shape, a flat shape, a cuboid shape, or other shapes, and the embodiments of the present application do not limit this either.

[0057] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide a higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack, etc. The battery generally includes a box for encapsulating one or more battery cells. The box can prevent liquids or other foreign objects from affecting the charging or discharging of the battery cells.

[0058] The battery cell mentioned in the embodiments of the present application may include an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode plate, a negative electrode plate, and a separator. The battery cell mainly operates by the movement of metal ions between the positive electrode plate and the negative electrode plate. The positive electrode plate includes a positive current collector and a positive active material layer, and the positive active material layer is coated on the surface of the positive current collector; the positive current collector includes a positive coating area and a positive tab connected to the positive coating area. The positive coating area is coated with the positive active material layer, and the positive tab is not coated with the positive active material layer. Taking a lithium-ion battery cell as an example, the material of the positive current collector can be aluminum, and the positive active material layer includes a positive active material, and the positive active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, etc. The negative electrode plate includes a negative current collector and a negative active material layer, and the negative active material layer is coated on the surface of the negative current collector; the negative current collector includes a negative coating area and a negative tab connected to the negative coating area. The negative coating area is coated with the negative active material layer, and the negative tab is not coated with the negative active material layer. The material of the negative current collector can be copper, and the negative active material layer includes a negative active material, and the negative active material can be carbon or silicon, etc. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc.

[0059] Currently, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in many fields such as military equipment and aerospace. With the continuous expansion of the application fields of power batteries, the market demand is also constantly increasing.

[0060] The battery cell is an important part of the power battery. During the cycling process of the battery cell, abnormal conditions may occur. For example, after the battery cell undergoes multiple charge and discharge cycles, side reactions may occur inside the battery cell and continuously generate gas. The gas will increase the internal pressure of the battery cell, which may further lead to the risk of deformation and rupture of the outer shell.

[0061] Currently, a pressure relief mechanism is provided in the battery cell. The pressure relief mechanism of the battery cell releases pressure when abnormal pressure occurs inside the battery, reducing the possibility of the battery exploding or causing danger due to overpressure. However, when the pressure relief mechanism is opened, it means that the internal pressure of the battery cell has reached an abnormal level. At this time, the battery cell will no longer be able to work with the opening of the pressure relief mechanism, resulting in the termination of its service life.

[0062] Therefore, how to always reduce the internal pressure of the battery cell, thereby reducing the possibility of the pressure relief mechanism opening prematurely, and thus extending the service life of the battery cell is an important topic in the research and development of battery cells and their related components.

[0063] In view of this, the present application provides a technical solution. By opening a first exhaust hole for auxiliary exhaust on the first wall of the battery cell and installing a breathable valve assembly at the first exhaust hole, the gas in the battery cell can flow out through the breathable valve assembly, so as to reduce the internal pressure of the battery cell, reduce the possibility of premature opening of the pressure relief mechanism, and improve the service life of the battery cell.

[0064] The battery cell described in the embodiments of the present application is applicable to batteries and electrical devices using the batteries.

[0065] The electrical device can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, etc. The vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or an extended-range electric vehicle, etc.; the spacecraft includes an airplane, a rocket, a space shuttle, a spaceship, etc.; the electric toy includes a fixed or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy, an electric airplane toy, etc.; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool and a railway electric tool, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, a hammer drill, an impact electric drill, a concrete vibrator, a planer, etc. The embodiments of the present application do not impose special restrictions on the above electrical devices.

[0066] For the convenience of description, the following embodiments take the electrical device as a vehicle as an example for illustration.

[0067] Combined with the attached Figure 1 As shown in the figure, the vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or an extended-range electric vehicle, etc. The vehicle 1000 is internally provided with a battery 100. The battery 100 can be arranged at the bottom, head or tail of the vehicle 1000. The battery 100 can be used for power supply of the vehicle 1000. For example, the battery 100 can be used as the operating power source of the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300. For example, it is used for the working power requirements during the start, navigation and driving of the vehicle 1000.

[0068] In some embodiments of the present application, the battery 100 can not only be used as the operating power source of the vehicle 1000, but also be used as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0069] Combined with the attached Figure 2As shown in the figure, the battery 100 includes a box body 10 and battery cells 20, and the battery cells 20 are accommodated in the box body 10. Among them, the box body 10 is used to provide an accommodation space for the battery cells 20, and the box body 10 can adopt various structures. In some embodiments, the box body 10 may include a first part 11 and a second part 12, the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define an accommodation space for accommodating the battery cells 20. The second part 12 may be a hollow structure with one end open, and the first part 11 may be a plate-like structure. The first part 11 covers the open side of the second part 12 so that the first part 11 and the second part 12 jointly define an accommodation space; the first part 11 and the second part 12 may also both be hollow structures with one side open, and the open side of the first part 11 covers the open side of the second part 12. Of course, the box body 10 formed by the first part 11 and the second part 12 can be of various shapes, such as a cylinder, a cuboid, etc.

[0070] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 can be connected in series, in parallel, or in a mixed connection. A mixed connection means that there are both series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 can be directly connected in series, in parallel, or in a mixed connection together, and then the whole formed by the multiple battery cells 20 is accommodated in the box body 10; of course, the battery 100 can also be that multiple battery cells 20 are first connected in series, in parallel, or in a mixed connection to form a battery module form, and then multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole and are accommodated in the box body 10. The battery 100 may further include other structures. For example, the battery 100 may further include a busbar component for realizing the electrical connection between the multiple battery cells 20.

[0071] Among them, each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc.

[0072] Combined with the attached Figures 3 - 9 As shown in the figure, an embodiment of the present application provides a battery cell 20, including a housing 22, an electrode assembly 23, a breathing valve assembly 212, and a protection member 213: The housing 22 has an accommodation cavity 222. The housing 22 includes a first wall 211. The first wall 211 has a first surface 2111 and a second surface 2112 facing away from each other. The second surface 2112 faces the outside of the battery cell 20. The first wall 211 is provided with a first exhaust hole 2113, and the first exhaust hole 2113 penetrates through the first surface 2111 and the second surface 2112; the electrode assembly 23 is accommodated in the accommodation cavity 222; the breathing valve assembly 212 is connected to the first wall 211 and covers the first exhaust hole 2113; the protection member 213 is detachably connected to the second surface 2112 and covers the breathing valve assembly 212.

[0073] The housing 22 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 22 can be determined according to the specific shape and size of the electrode assembly 23. The material of the housing 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special restrictions on this. In some examples, a first insulating film layer 22a can be provided on the inner side of the housing 22, and a second insulating film layer 22b can be provided on the outer side. The electrode assembly 23 is a component in the battery 100 where an electrochemical reaction occurs. The housing 22 can contain one or more electrode assemblies 23.

[0074] The first wall 211 in this embodiment can be a side wall or a bottom wall of the housing 22, or can also be the end cap body of the end cap assembly 21 in the housing 22. Hereinafter, taking the first wall 211 as the end cap body of the end cap assembly 21 as an example for illustration.

[0075] The end cap assembly 21 refers to a component that covers the opening 221 of the housing 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap assembly 21 can be adapted to the shape of the opening 221 of the housing 22 to cooperate with the opening 221. Optionally, the end cap assembly 21 can be made of a material (such as aluminum alloy) with a certain hardness and strength. In this way, the end cap assembly 21 is not easily deformed when being squeezed or collided, enabling the battery cell 20 to have a higher structural strength and the safety performance can also be improved. Functional components such as electrode terminals 21a can be provided on the end cap assembly 21. The electrode terminal 21a can be electrically connected to the electrode assembly 23 through a jumper 24 for outputting or inputting the electrical energy of the battery cell 20.

[0076] The first wall 211 in this embodiment can be made of a material (such as aluminum alloy) with a certain hardness and strength. The first wall 211 has opposite first surface 2111 and second surface 2112. After the battery cell 20 is assembled and formed, the first surface 2111 of the first wall 211 faces the electrode assembly 23 of the battery cell 20. The shape of the first wall 211 can be a rectangular plate shape as shown in the figure, or can also be other shapes, which can be specifically determined according to the shape of the opening 221 of the housing 22 of the battery cell 20, and this embodiment does not list them one by one.

[0077] Electrode terminals 21a are installed at both ends of the first wall 211. The aforementioned first exhaust hole 2113 is provided between the two electrode terminals 21a. The breather valve assembly 212 is connected to the first wall 211 and covers the first exhaust hole 2113. The breather valve assembly 212 can be connected to the first surface 2111.

[0078] When the internal pressure of the battery cell 20 increases, some of the gas inside the battery cell 20 can be discharged from the vent valve assembly 212 along the first direction X to the first exhaust hole 2113, and finally the first exhaust hole 2113 discharges this part of the gas outside the battery cell 20 to reduce the air pressure inside the battery cell 20, thereby reducing the risk that the battery 100 cannot be used due to the pressure relief mechanism 215 being opened due to excessive air pressure. This helps to improve the stability and service life of the battery cell 20.

[0079] The material of the protective member 213 can be metal or plastic. The protective member 213 is connected to the second surface 2112 of the first wall 211, and the protective member 213 can be removed after the battery cell 20 is assembled and before the insulating patch 216 is installed.

[0080] In some examples, the protective member 213 is adhesively bonded, snap-connected or connected by a connecting member to the second surface 2112, and the connecting member is respectively detachably connected to the first wall 211 and the protective member 213. The connecting member can be a structure such as a screw.

[0081] By providing a removable protective member 213 to protect the first exhaust hole 2113, the possibility of foreign impurities entering the vent valve assembly 212 during the production of the battery cell 20 and affecting the exhaust function is reduced, the reliability of the vent valve assembly 212 is improved, and the protective member 213 can be directly removed when needed, facilitating the subsequent attachment of the insulating patch 216.

[0082] Combined with the attached Figure 6 、attached Figure 10 and attached Figure 11 In some examples, optionally, the protective member 213 is adhesively bonded to the first surface 2111. The protective member 213 includes a protective layer 2131 and an adhesive layer 2132. The adhesive layer 2132 is connected to the side of the protective layer 2131 facing the second surface 2112 and is adhesively bonded to the second surface 2112.

[0083] The material of the adhesive layer 2132 can be solid glue, and the material of the protective layer 2131 can be metal or plastic. The protective member 213 of this embodiment is adhesively bonded to the second surface 2112 by using the adhesive layer 2132. When installing the protective member 213, the protective member 213 can be directly pressed on the second surface 2112 of the first wall 211. When removing, the protective member 213 can be directly torn off, improving the installation efficiency and removal efficiency of the protective member 213.

[0084] In some examples, optionally, the adhesive layer 2132 of this embodiment is disposed around the first exhaust hole 2113.

[0085] The adhesive layer 2132 is arranged to surround the first exhaust hole 2113 . The adhesive layer 2132 and the protective layer 2131 form a relatively closed space, which can better protect the first exhaust hole 2113 and further reduce the possibility of foreign matter and impurities entering the first exhaust hole 2113 during the production process of the battery cell 20 .

[0086] Combined with Figure 11 As shown in , in some examples, optionally, the protective layer 2131 of this embodiment includes a main body 21312 and an extension ear 21313, the main body 21312 is connected to the second surface 2112, the extension ear 21313 is connected to the edge of the main body 21312, and has a gap 21314 with the second surface 2112.

[0087] The formation of the gap 21314 eliminates any connection between the extension ear 21313 and the second surface 2112 , so that the operator can directly tear off the protective member 213 by holding the extension ear 21313 , thereby improving the removal efficiency of the protective member 213 .

[0088] The extension ear 21313 and the protective layer 2131 may be integrally connected by welding or bonding, or may be integrally formed directly during processing. The shape of the extension ear 21313 may be approximately rectangular, and of course may also be other shapes such as circular, triangular, etc., which are not listed one by one in this embodiment.

[0089] In some examples, optionally, a size of the gap 21314 in the first direction X gradually increases from one end of the extension ear 21313 connected to the body 21312 to the end of the extension ear 21313 away from the body 21312 .

[0090] This structure enables the extension ear 21313 to form a tilted structure relative to the second surface 2112, which is more convenient for the operator or operating equipment to clamp the extension ear 21313 when removing the protective member 213, thereby further improving the removal efficiency of the protective member.

[0091] In some examples, optionally, the protection member 213 of this embodiment is provided with a through hole 21311 , and the through hole 21311 passes through the protection member 213 along the first direction X.

[0092] The through hole 21311 can be used to connect the first exhaust hole 2113 and the breathable valve assembly 212, so as to facilitate the detection of the working performance of the breathable valve assembly 212 of this embodiment before installing the insulating patch 216. At the same time, when the adhesive layer 2132 of this embodiment is arranged to surround the first exhaust hole 2113, the adhesive layer 2132 will not cover the first exhaust hole 2113, which is further conducive to the detection of the working performance of the breathable valve assembly 212 of this embodiment.

[0093] In some examples, optionally, the maximum dimension of the through-hole 21311 of the present embodiment in the second direction Y is smaller than the maximum dimension of the first exhaust hole 2113 in the second direction Y. The second direction Y is parallel to the first surface 2111 and is parallel or intersects with the extending direction of the first wall 211.

[0094] That is, the aperture of the through-hole 21311 of the present embodiment is smaller than the aperture of the first exhaust hole 2113. For example, the aperture of the through-hole 21311 is less than one-tenth of the aperture of the first exhaust hole 2113. The smaller the aperture of the through-hole 21311, the better the barrier performance against foreign impurities in the outside world. Therefore, the possibility of foreign impurities directly entering the first exhaust hole 2113 through the through-hole 21311 can be reduced.

[0095] In some examples, optionally, the maximum dimension of the through-hole 21311 of the present embodiment in the first direction X is less than or equal to 1 mm.

[0096] For example, the aperture of the through-hole 21311 can be 1 mm, 0.5 mm, 0.1 mm, etc. Designing the maximum dimension of the through-hole 21311 in the first direction X within the above numerical range can further reduce the possibility of foreign impurities entering the through-hole 21311.

[0097] Combined with the attached Figure 6 、attached Figure 8 and attached Figure 12 As shown in the figures, in some examples, optionally, the breathing valve assembly 212 of the present embodiment includes a first valve body 2121 and a breathable membrane layer 2122. The first valve body 2121 is connected to the first wall 211 and is provided with a second exhaust hole 21211. The second exhaust hole 21211 penetrates the first valve body 2121 in the first direction X and communicates with the first exhaust hole 2113. The breathable membrane layer 2122 is connected to the side of the first valve body 2121 facing away from the first wall 211 and covers the second exhaust hole 21211.

[0098] The first valve body 2121 can be in the shape of a disc shown in the figure, and its material can be selected from plastics or metals. The breathable membrane layer 2122 is connected to the surface of the first valve body 2121 facing away from the first wall 211. The shapes of the breathable membrane layer 2122 and the first valve body 2121 are both designed as sheets, which can reduce the size of the entire breathing valve assembly 212 in the first direction X.

[0099] The breathable membrane layer 2122 allows gas to pass through in the direction from Figure 6 the first surface 2111 to the second surface 2112 in the figure. The breathable membrane layer 2122 can be made of materials such as polypropylene, polyethylene, polytetrafluoroethylene, polyester, polyurethane, etc.

[0100] In this embodiment, the ventilation valve assembly 212 is designed to include a first valve body 2121 and a ventilation membrane layer 2122, which can not only achieve the function of exhausting gas, but also have a relatively small overall size in the first direction X under this structure, reducing the influence on the installation of other accessory structures (such as the insulating part 214) of the ventilation valve assembly 212 in the end cap assembly 21.

[0101] In some examples, optionally, a first groove 21111 and a second groove 21112 that communicate with each other are successively formed in the first surface of this embodiment along the first direction X. The second groove 21112 is communicated with the first exhaust hole 2113. In the second direction, the maximum dimension of the first groove 21111 is greater than the maximum dimension of the second groove 21112, and the maximum dimension of the second groove 21112 is greater than the maximum dimension of the first exhaust hole 2113. The second direction Y is parallel to the first surface 2111 and is parallel or intersects with the extending direction of the first wall 211; the first valve body 2121 is installed in the first groove 21111.

[0102] By providing the first groove 21111 and the second groove 21112, the first valve body 2121 located in the first groove 21111 is communicated with the first exhaust hole 2113 through the second groove 21112. The dimensions of the first valve body 2121, the second groove 21112, and the first exhaust hole 2113 gradually decrease in the second direction, reducing the risk of gas turbulence caused by gas directly entering the first exhaust hole 2113 from the first valve body 2121 with a larger dimension, which is beneficial to the concentrated discharge of gas.

[0103] In some examples, optionally, the number of the second exhaust holes 21211 in this embodiment is multiple. The multiple second exhaust holes 21211 are beneficial to the discharge of gas inside the battery cell 20.

[0104] In some embodiments, one of the multiple second exhaust holes 21211 is arranged in the middle of the first valve body 2121, and the remaining second exhaust holes 21211 are arranged around the second exhaust hole 21211 located in the middle of the first valve body 2121.

[0105] The distance between two adjacent second exhaust holes 21211 is less than the aperture of each second exhaust hole 21211. The middle of the first valve body 2121 refers to the center of the first valve body 2121 in the second direction Y. When the first valve body 2121 in this embodiment is in the disk-shaped structure shown in the figure, the middle of the first valve body 2121 refers to the center position of the first valve body 2121.

[0106] By arranging a plurality of second exhaust holes 21211 around the middle second exhaust hole 21211, the layout density of the second exhaust holes 21211 can be increased to a certain extent, which is more conducive to the connection between the second exhaust holes 21211 and the first exhaust holes 2113.

[0107] Combined with the attached Figure 6 and the attached Figure 7 As shown in the figure, in some examples, optionally, the end cap assembly 21 of this embodiment further includes an insulating member 214. The insulating member 214 is connected to the first wall 211. The insulating member 214 is provided with a third exhaust hole 2141. The breather valve assembly 212 is located between the first wall 211 and the insulating member 214 and covers the third exhaust hole 2141.

[0108] The material of the insulating member 214 can be selected from insulating materials such as plastics and rubbers. The insulating member 214 is connected to the first surface 2111 of the first wall 211. The connection method can be realized through the connecting columns shown in the figure. The connecting columns and the first wall 211 can be in plug-in fit or threaded connection.

[0109] The insulating member 214 is provided with an exhaust structure 2142 that is disposed opposite to the first wall 211 in the first direction X. The exhaust structure 2142 is used to cooperate with the pressure relief mechanism 215 to achieve pressure relief when the internal pressure reaches the threshold value. Moreover, in order to realize the exhaust when the internal pressure rises but does not reach the threshold value for opening the pressure relief mechanism 215, the insulating member 214 of this embodiment is provided with a third exhaust hole 2141 that is communicated with the first exhaust hole 2113 through the breather valve assembly 212.

[0110] In this way, the insulating member 214 can be used to isolate the electrical connection components inside the battery cell 20 from the first wall 211 to reduce the risk of short circuit. At the same time, by arranging the breather valve assembly 212 of this embodiment between the first wall 211 and the insulating member 214, the stability of the breather valve assembly 212 after installation can be improved.

[0111] In some examples, optionally, the projection of the second exhaust hole 21211 on the insulating member 214 in the first direction X is located within the third exhaust hole 2141.

[0112] The projection of the second exhaust hole 21211 on the insulating member 214 in the first direction X can be understood as the projection on the plane where the side of the insulating member 214 facing the first wall 211 is located, rather than that the projection must be on a certain physical structure of the insulating member 214, because the presence of the third exhaust hole 2141 may not directly form a projection.

[0113] This structure makes the aperture diameter of the third exhaust hole 2141 greater than or equal to that of the second exhaust hole 21211, which is conducive to the gas in the battery cell 20 entering the breather valve assembly 212 through the third exhaust hole 2141, thereby improving the exhaust efficiency.

[0114] In some examples, optionally, the maximum dimension a of the third exhaust hole 2141 in the second direction Y can be greater than the maximum dimension b of the first exhaust hole 2113 in the first direction X. The second direction Y is parallel to the first surface 2111 and is parallel or intersects with the extending direction of the first wall 211.

[0115] That is, the aperture diameter of the third exhaust hole 2141 is greater than that of the aforementioned first exhaust hole 2113. For example, the aperture diameter of the third exhaust hole 2141 is 2 - 10 times that of the first exhaust hole 2113. The larger third exhaust hole 2141 is conducive to the gas in the battery cell 20 passing through the third exhaust hole 2141 and the breather valve assembly 212 and entering the first exhaust hole 2113, which can improve the exhaust efficiency.

[0116] Again referring to the appendix Figure 9 As shown in the figure, in some examples, optionally, the end cap assembly 21 further includes a pressure relief mechanism 215. The first wall 211 is provided with a fourth exhaust hole 2114. The pressure relief mechanism 215 is connected to the first surface 2111 and seals the fourth exhaust hole 2114.

[0117] The pressure relief mechanism 215 refers to an element or component that actuates to release the internal pressure or temperature when the internal pressure or temperature of the battery cell reaches a predetermined threshold. This threshold design varies according to different design requirements. The threshold may depend on one or several materials among the positive electrode plate, negative electrode plate, electrolyte, and separator in the battery cell. The pressure relief mechanism 215 can adopt forms such as an explosion-proof valve, gas valve, pressure relief valve, or safety valve, and can specifically adopt a pressure-sensitive or temperature-sensitive element or structure. That is, when the internal pressure or temperature of the battery cell reaches a predetermined threshold, the pressure relief mechanism 215 performs an action or a weak structure provided in the pressure relief mechanism is damaged, thereby forming an opening or channel for the internal pressure or temperature to be released. By using the pressure relief mechanism 215, the gas can be discharged when the internal pressure in the battery cell 20 is too high, reducing the risk of the battery cell 20 exploding due to excessive internal air pressure.

[0118] Please refer to Figures 3 - 12, an embodiment of the present application provides a battery cell 100, which includes a housing 22, an electrode assembly 23, a breather valve assembly 212, and a protection member 213. The housing 22 has a receiving cavity 222. The housing 22 includes a first wall 211. The first wall 211 has a first surface 2111 and a second surface 2112 facing away from each other. The second surface 2112 faces the outside of the battery cell 100. The first wall 211 is provided with a first exhaust hole 2113, and the first exhaust hole 2113 penetrates through the first surface 2111 and the second surface 2112; the electrode assembly 23 is received in the receiving cavity 222; the breather valve assembly 212 is connected to the first wall 211 and covers the first exhaust hole 2113; the protection member 213 is detachably connected to the second surface 2112 and covers the breather valve assembly 212. The protection member 213 is adhesively bonded, snap-connected or connected by a connecting member to the second surface 2112, and the connecting member is detachably connected to the first wall 211 and the protection member 213 respectively. The protection member 213 is adhesively bonded to the second surface 2112. The protection member 213 includes a protective layer 2131 and an adhesive layer 2132. The adhesive layer 2132 is connected to the side of the protective layer 2131 facing the second surface 2112 and is adhesively bonded to the second surface 2112. The adhesive layer 2132 is disposed around the first exhaust hole 2113. The protective layer 2131 includes a body 21312 and an extension ear 21313. The body 21312 is connected to the second surface 2112. The extension ear 21313 is connected to the edge of the body 21312 and has a gap 21314 with the second surface 2112. From the end where the extension ear 21313 is connected to the body 21312 to the end where the extension ear 21313 faces away from the body 21312, the gap 21314 between the extension ear 21313 and the second surface 2112 gradually increases. The protection member 213 is provided with a through hole 21311, and the through hole 21311 penetrates through the protection member 213 along the first direction X. The maximum dimension of the through hole 21311 in the second direction Y is smaller than the maximum dimension of the first exhaust hole 2113 in the second direction Y. The second direction Y is parallel to the first surface 2111 and is parallel or intersects with the extending direction of the first wall 211. The maximum dimension of the through hole 21311 in the second direction Y is less than or equal to 1 mm. The breather valve assembly 212 includes a first valve body 2121 and a breathable membrane layer 2122. The first valve body 2121 is connected to the first wall 211 and is provided with a second exhaust hole 21211. The second exhaust hole 21211 penetrates through the first valve body 2121 along the first direction X and is communicated with the first exhaust hole 2113; the breathable membrane layer 2122 is connected to the side of the first valve body 2121 facing away from the first wall 211 and covers the second exhaust hole 21211.The first surface 2111 is successively provided with a first groove 21111 and a second groove 21112 that communicate with each other along the first direction X. The second groove 21112 communicates with the first exhaust hole 2113. In the second direction Y, the maximum dimension of the first groove 21111 is greater than the maximum dimension of the second groove 21112, and the maximum dimension of the second groove 21112 is greater than the maximum dimension of the first exhaust hole 2113. The second direction Y is parallel to the first surface 2111 and is parallel or intersects with the extending direction of the first wall 211; at least a part of the first valve body 2121 is installed in the first groove 21111. The number of the second exhaust holes 21211 is multiple. One of the multiple second exhaust holes 21211 is located in the middle of the first valve body 2121, and the remaining second exhaust holes 21211 are arranged around the second exhaust hole 21211 located in the middle of the first valve body 2121. The battery 100 cell further includes an insulating member 214. The insulating member 214 is connected to the first wall 211. The insulating member 214 is provided with a third exhaust hole 2141. The breather valve assembly 212 is located between the first wall 211 and the insulating member 214 and communicates with the third exhaust hole 2141. The projection of the second exhaust hole 21211 on the insulating member 214 along the first direction X is located in the third exhaust hole 2141. The battery 100 cell further includes a pressure relief mechanism 215. The first wall 211 is provided with a fourth exhaust hole 2114. The pressure relief mechanism 215 seals the fourth exhaust hole 2114.

[0119] The first wall 211 is the end cover body of the end cover assembly 21 or a wall of the outer shell 22.

[0120] Finally, in combination with the attached Figure 13 As shown in the figure, based on the above battery cell 20, battery 100, and the electrical device, the embodiment of the present application further provides a method for manufacturing a battery 100 cell, including the following steps:

[0121] Cover a protective member 213 at the first exhaust hole 2113 of the battery 100 cell. The first exhaust hole 2113 is communicated with a breather valve assembly 212, and the breather valve assembly 212 is used to exhaust gas from the inside of the battery 100 cell to the outside;

[0122] Tear off the protective member 213.

[0123] In some examples, optionally, before tearing off the protective member 213, it further includes performing a sealing nail welding process on the battery 100 cell. The sealing nail is used to block the liquid injection hole, and the sealing nail can be made of insulating or non-insulating material. The sealing nail can be welded on the end cover assembly 21.

[0124] In some examples, optionally, after tearing off the protective member 213, it further includes performing an insulating film coating process on the battery 100 cell. The insulating film can be a blue film.

[0125] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell, characterized in that, it includes: A housing having a receiving cavity. The housing includes a first wall having opposite first and second surfaces, the second surface facing the outside of the battery cell. The first wall is provided with a first exhaust hole that penetrates the first and second surfaces; An electrode assembly received in the receiving cavity; A breather valve assembly connected to the first wall and covering the first exhaust hole; and A protective member removably connected to the second surface and covering the breather valve assembly.

2. The battery cell according to claim 1, characterized in that, The protective member is adhesively bonded, snap-connected or connected by a connecting member to the second surface, and the connecting member is detachably connected to the first wall and the protective member respectively.

3. The battery cell according to claim 2, characterized in that, The protective member is adhesively bonded to the second surface. The protective member includes a protective layer and an adhesive layer. The adhesive layer is connected to the side of the protective layer facing the second surface and is adhesively bonded to the second surface.

4. The battery cell according to claim 3, characterized in that, The adhesive layer is disposed around the first exhaust hole.

5. The battery cell according to claim 3, characterized in that, The protective layer includes a body and an extension ear. The body is connected to the second surface, and the extension ear is connected to the edge of the body and has a gap with the second surface.

6. The battery cell according to claim 5, characterized in that, From the end where the extension ear is connected to the body to the end where the extension ear faces away from the body, the size of the gap in the first direction gradually increases.

7. The battery cell according to claim 3, characterized in that, The protective layer is provided with a through hole that penetrates the protective member in the first direction.

8. The battery cell according to claim 7, characterized in that, The maximum dimension of the through hole in the second direction is smaller than the maximum dimension of the first exhaust hole in the second direction. The second direction is parallel to the first surface and is parallel or intersects with the extending direction of the first wall.

9. The battery cell according to claim 8, characterized in that, The maximum dimension of the through hole in the second direction is less than or equal to 1 mm.

10. The battery cell according to claim 1, characterized in that, The breather valve assembly includes: A first valve body connected to the first wall and provided with a second exhaust hole. The second exhaust hole penetrates the first valve body in the first direction and is communicated with the first exhaust hole; A breathable membrane layer connected to the side of the first valve body facing away from the first wall and covering the second exhaust hole.

11. The battery cell according to claim 10, characterized in that, The first surface is successively provided with a first groove and a second groove that communicate with each other along the first direction. The second groove communicates with the first exhaust hole. In the second direction, the maximum dimension of the first groove is greater than the maximum dimension of the second groove, and the maximum dimension of the second groove is greater than the maximum dimension of the first exhaust hole. The second direction is parallel to the first surface and is parallel or intersects with the extending direction of the first wall. At least a part of the first valve body is installed in the first groove.

12. The battery cell according to claim 11, wherein, the number of the second exhaust holes is multiple.

13. The battery cell according to claim 12, wherein, one of the multiple second exhaust holes is located in the middle of the first valve body, and the remaining second exhaust holes are arranged around the second exhaust hole located in the middle of the first valve body.

14. The battery cell according to claim 10, wherein, the battery cell further includes an insulating member. The insulating member is connected to the first wall. The insulating member is provided with a third exhaust hole. The breathing valve assembly is located between the first wall and the insulating member and communicates with the third exhaust hole.

15. The battery cell according to claim 14, wherein, the projection of the second exhaust hole on the insulating member along the first direction is located in the third exhaust hole.

16. The battery cell according to claim 1, wherein, the battery cell further includes a pressure relief mechanism. The first wall is provided with a fourth exhaust hole. The pressure relief mechanism seals the fourth exhaust hole.

17. The battery cell according to any one of claims 1-16, wherein, the first wall is the end cover body of the end cover assembly or a wall of the outer shell.

18. A battery, wherein, it includes the battery cell according to claim 17.

19. An electrical device, wherein, it includes the battery according to claim 18, and the battery is used to provide electrical energy.

20. A method for manufacturing a battery cell, wherein, it includes the following steps: covering a protective member at the first exhaust hole of the battery cell. The first exhaust hole communicates with a breathing valve assembly, and the breathing valve assembly is used to exhaust gas from the inside of the battery cell to the outside; tearing off the protective member.

21. The method for manufacturing a battery cell according to claim 20, wherein, before tearing off the protective member, it further includes performing a sealing nail welding process on the battery cell.

22. The method for manufacturing a battery cell according to claim 20 or 21, wherein, after tearing off the protective member, it further includes performing an insulating film coating process on the battery cell.

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