Battery cell, battery, electrical apparatus, and battery cell production method

Abstract

A battery cell (20), a battery (100), an electrical apparatus, and a production method for a battery cell (20). The battery cell (20) comprises a casing (22), an electrode assembly (23), an air-permeable valve assembly (212), and a protective component (213); the casing (22) is provided with an accommodating cavity (222); the casing (22) comprises a first wall (211); the first wall (211) is provided with a first surface (2111) and a second surface (2112) that face away from each other; the second surface (2112) faces the outside of the battery cell (20); a first vent hole (2113) is formed in the first wall (211); the first vent hole (2113) passes through the first surface (2111) and the second surface (2112); the electrode assembly (23) is accommodated in the accommodating cavity (222); the air-permeable valve assembly (212) is connected to the first wall (211) and covers the first vent hole (2113); the protective component (213) is detachably connected to the second surface (2112) and covers the air-permeable valve assembly (212). The detachable protective component (213) is provided to protect the air-permeable valve assembly (212), thereby reducing the possibility that foreign matter and impurities enter the air-permeable valve assembly (212) and impact the venting function during the production process of the battery cell (20), and improving the reliability of the air-permeable valve assembly (212).

Description

Battery cell, battery, electric device and battery cell production method

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application 202311643162.2, entitled “Battery Cell, Battery, Electrical Device, and Battery Cell Production Method,” filed on November 30, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of battery technology, and more particularly, to a battery cell, a battery, an electrical device, and a method for producing the battery cell. Background Art

[0004] Battery cells are widely used in electronic devices such as mobile phones, laptop computers, electric vehicles, electric cars, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes and power tools, etc.

[0005] In order to reduce the internal air pressure of the battery cells, some battery cells are provided with a vent valve assembly. However, during the production process of the battery cells, foreign matter and impurities can easily enter the vent valve assembly, affecting the exhaust function of the vent valve assembly and even causing damage to the vent valve assembly.

[0006] Summary of the Invention

[0007] The present application provides a battery cell, a battery, an electrical device, and a battery cell production method, which can reduce the risk of damage to the vent valve assembly on the battery cell.

[0008] In a first aspect, an embodiment of the present application provides a battery cell, comprising: a housing having a housing cavity, the housing including a first wall, the first wall having a first surface and a second surface opposite to each other, the second surface facing the exterior of the battery cell, the first wall being provided with a first vent, the first vent extending through the first and second surfaces; an electrode assembly housed within the housing cavity; a vent assembly connected to the first wall and covering the first vent; and a protective member removably connected to the second surface and covering the vent assembly. By providing a removable protective member to protect the second vent, the possibility of foreign matter and impurities entering the vent assembly and affecting its venting function during battery cell production is reduced, thereby improving the reliability of the vent assembly.

[0009] In some embodiments, the protective member is bonded to the second surface, snap-fitted, or connected via a connector, and the connector is removably connected to the first wall and the protective member, respectively. The removable connection between the protective member and the second surface achieved through bonding, snap-fitting, or connecting means provides a simple structure and facilitates assembly and disassembly.

[0010] In some embodiments, the protective member is bonded to the second surface and includes a protective layer and an adhesive layer, wherein the adhesive layer is connected to a side of the protective layer facing the second surface and is bonded to the second surface. Bonding the protective member to the second surface facilitates installation and removal of the protective member.

[0011] In some embodiments, the adhesive layer is disposed around the first vent. Arranging the adhesive layer around the first vent creates a relatively enclosed space with the protective layer, thereby better protecting the first vent and further reducing the possibility of foreign matter or impurities entering the first vent during battery cell production.

[0012] In some embodiments, the protective layer includes a main body and an extension ear, wherein the main body is connected to the second surface, and the extension ear is connected to the edge of the main body and has a gap with the second surface. By providing the extension ear, when removing the protective member, an operator or an operating instrument can grasp the extension ear and directly tear off the protective member, thereby improving the removal efficiency of the protective member.

[0013] In some embodiments, the gap gradually increases in size in a first direction from the end of the extension ear connected to the body to the end of the extension ear facing away from the body, where the first direction is the direction of arrangement from the first surface to the second surface. By designing the gap between the extension ear and the second surface to gradually increase in size in the first direction, the extension ear forms a tilted structure, making it easier for an operator or operating equipment to grasp the extension ear, further improving the efficiency of removing the protective member.

[0014] In some embodiments, the protective member includes a through hole extending through the protective member in a first direction, where the first direction is the direction from the first surface to the second surface. The through hole connects the first vent hole and the vent valve assembly, facilitating performance testing of the vent valve assembly of this embodiment prior to installation of the insulating patch.

[0015] In some embodiments, the maximum dimension of the through hole along the second direction is smaller than the maximum dimension of the first vent 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. Designing the maximum dimension of the through hole to be smaller than the maximum dimension of the first vent hole reduces the possibility of foreign matter or impurities directly entering the first vent hole through the through hole.

[0016] In some embodiments, the maximum dimension of the through hole along the second direction is less than or equal to 1 mm. Setting the maximum dimension of the through hole in the second direction to the above value can further reduce the possibility of foreign matter and impurities entering the through hole.

[0017] In some embodiments, the breathable valve assembly includes: a first valve body connected to the first wall and having a second vent, the second vent extending through the first valve body in a first direction and communicating with the first vent, the first direction being the direction of arrangement from the first surface to the second surface; and a breathable membrane layer connected to the side of the first valve body facing away from the first wall and covering the second vent. Designing the breathable valve assembly to include the first valve body and the breathable membrane layer not only achieves the venting function, but also reduces the overall size of the vent valve in the first direction, thereby reducing the impact on other ancillary structures of the end cap assembly during installation.

[0018] In some embodiments, the first surface is sequentially formed with a first groove and a second groove intersecting the first vent along the first direction. The second groove is connected to the first vent. 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 vent. The second direction is parallel to the first surface and parallel to or intersecting with the extension direction of the first wall. The first valve body is at least partially mounted within the first groove. By providing the first and second grooves, the first valve body located within the first groove is connected to the first vent via the second groove. The dimensions of the first valve body, the second groove, and the first vent gradually decrease in the second direction, facilitating the centralized discharge of gas.

[0019] In some embodiments, the number of the second exhaust holes is multiple, which facilitates the discharge of gas.

[0020] In some embodiments, one of the plurality of second exhaust holes is located in the center of the first valve body, and the remaining second exhaust holes are arranged around the second exhaust hole located in the center of the first valve body. This structure can increase the density of the second exhaust holes to a certain extent, further facilitating the flow of gas from the second exhaust holes into the second groove.

[0021] In some embodiments, the battery cell further includes an insulating member connected to the first wall, the insulating member defining a third vent hole, and the vent valve assembly being located between the first wall and the insulating member and communicating with the third vent hole. Placing the vent valve assembly between the first wall and the insulating member can improve the stability of the vent valve assembly after installation.

[0022] In some embodiments, the projection of the second vent hole on the insulating member along the first direction is located within the third vent hole. This structure ensures that the diameter of the fifth vent hole is greater than or equal to the diameter of the fourth vent hole, which facilitates the entry of gas within the battery cell into the vent valve assembly through the fifth vent hole, thereby improving venting efficiency.

[0023] In some embodiments, the battery cell further includes a pressure relief mechanism, the first wall is provided with a fourth vent hole, and the pressure relief mechanism seals the fourth vent hole. The pressure relief mechanism can be used to discharge gas when the internal pressure of the battery cell is too high, thereby reducing the risk of the battery cell exploding due to excessive internal pressure.

[0024] In some embodiments, the first wall is a wall of an end cap body or housing of the end cap assembly.

[0025] In a second aspect, an embodiment of the present application further provides a battery comprising a battery cell as described in any one of the above technical solutions.

[0026] In a third aspect, an embodiment of the present application further provides an electrical device comprising the above-mentioned battery, which is used to provide electrical energy.

[0027] In a fourth aspect, an embodiment of the present application also provides a battery cell production method, comprising the following steps: covering a first exhaust hole of the battery cell with a protective member, wherein the first exhaust hole is connected to a breathable valve assembly, and the breathable valve assembly is used to discharge gas from the inside of the battery cell to the outside; and tearing off the protective member.

[0028] In some embodiments, before removing the protective member, a sealing nail welding process is further performed on the battery cell.

[0029] In some embodiments, after the protective member is removed, the method further includes wrapping the battery cell with an insulating film. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0031] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0032] FIG2 is a schematic structural diagram of a battery provided in some embodiments of the present application;

[0033] FIG3 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0034] FIG4 is a schematic diagram of the exploded structure of an end cap assembly provided in some embodiments of the present application;

[0035] FIG5 is a schematic structural diagram of an end cap assembly provided in some embodiments of the present application;

[0036] FIG6 is a cross-sectional view taken along line AA of FIG5 ;

[0037] FIG7 is a schematic structural diagram of an end cap assembly provided in some embodiments of the present application after the protective member is removed;

[0038] FIG8 is a BB cross-sectional view of FIG7;

[0039] FIG9 is a schematic diagram of the exploded structure of an end cap assembly provided in some embodiments of the present application;

[0040] FIG10 is a schematic structural diagram of a protective component of a battery cell provided in some embodiments of the present application;

[0041] FIG11 is a schematic diagram illustrating the connection between a protective member and a second surface of a battery cell provided in some embodiments of the present application;

[0042] FIG12 is a schematic structural diagram of a vent valve assembly of a battery cell provided in some embodiments of the present application;

[0043] FIG13 is a flow chart of a battery cell production method provided in some embodiments of the present application.

[0044] The reference numerals of the specific embodiments are as follows: 1000, vehicle; 100, battery; 10, housing; 11, first portion; 12, second portion; 20, battery cell; 21, end cap assembly; 211, first wall; 2111, first surface; 21111, first groove; 21112, second groove; 2112, second surface; 2113, first vent; 2114, fourth vent; 212, breathable valve assembly; 2121, first valve body; 21211, second vent; 2122, breathable film layer; 213, protective member; 2131, protective layer; 21311, through hole; 21312, body; 21313, extension ear; 21314, gap; 2132, adhesive layer; 214, insulating member; 2141, third vent; 2142, vent 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; 200, controller; 300, motor; X, first direction; Y, second direction. DETAILED DESCRIPTION

[0045] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0046] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0047] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0048] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," and "attached" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediary, or internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0049] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. 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 this application generally indicates that the related objects are in an "or" relationship.

[0050] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0051] The term "plurality" used in this application refers to two or more (including two).

[0052] In this application, battery cells may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells, or magnesium-ion battery cells, and the embodiments of this application are not limited thereto. Battery cells may be cylindrical, flat, rectangular, or in other shapes, and the embodiments of this application are not limited thereto.

[0053] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may include a battery module or a battery pack. A battery generally includes a casing that encloses one or more battery cells. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0054] The battery cell mentioned in the embodiments of the present application may include an electrode assembly and an electrolyte, and the electrode assembly includes a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer, and the positive electrode active material layer is coated on the surface of the positive electrode collector; the positive electrode collector includes a positive electrode coating area and a positive electrode tab connected to the positive electrode coating area, the positive electrode coating area is coated with a positive electrode active material layer, and the positive electrode tab is not coated with a positive electrode active material layer. Taking a lithium-ion battery cell as an example, the material of the positive electrode collector can be aluminum, and the positive electrode active material layer includes a positive electrode active material. The positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative current collector and a negative active material layer, which is coated on the surface of the current collector. The negative current collector includes a negative coating region and a negative tab connected to the negative coating region. The negative coating region is coated with the negative active material layer, while the negative tab is not coated with the negative active material layer. The negative current collector can be made of copper, and the negative active material layer includes a negative active material, which can be carbon or silicon. The separator can be made of materials such as PP (polypropylene) or PE (polyethylene).

[0055] Currently, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As the application of power batteries continues to expand, market demand is also growing.

[0056] Battery cells are an important component of power batteries. During their cycle life, abnormalities may occur. For example, after multiple charge and discharge cycles, side reactions may occur within the cells, continuously generating gas. This gas increases the internal pressure of the cells, potentially causing deformation or rupture of the outer shell.

[0057] Currently, all battery cells are equipped with pressure relief mechanisms. These mechanisms release pressure when abnormal pressure builds up inside the battery, reducing the possibility of explosion or other hazards caused by overpressure. However, when the pressure relief mechanism opens, it indicates that the internal pressure of the battery cell has reached an abnormal level. At this point, the battery cell will cease to function, ending its service life.

[0058] Therefore, how to constantly reduce the internal gas pressure of the battery cell, thereby reducing the possibility of premature opening of the pressure relief mechanism, and thus extending the service life of the battery cell is an important issue in the research and development of battery cells and related components.

[0059] In view of this, the present application provides a technical solution, which opens a first exhaust hole for auxiliary exhaust on the first wall of the battery cell, and installs a breathable valve assembly at the first exhaust hole, so that 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.

[0060] The battery cells described in the embodiments of the present application are suitable for use in batteries and electrical devices using the batteries.

[0061] Electrical devices may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. Vehicles may include fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles may include pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0062] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0063] As shown in FIG1 , 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 vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000. The battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 can also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, to meet the power requirements for starting, navigating and driving the vehicle 1000.

[0064] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0065] As shown in FIG2 , the battery 100 includes a housing 10 and a battery cell 20, which is housed within the housing 10. The housing 10 is used to provide a storage space for the battery cell 20 and can have various structures. In some embodiments, the housing 10 can include a first portion 11 and a second portion 12, which overlap each other and together define a storage space for the battery cell 20. The second portion 12 can be a hollow structure with one end open, and the first portion 11 can be a plate-like structure, overlapping the open side of the second portion 12, so that the first portion 11 and the second portion 12 together define a storage space. Alternatively, the first portion 11 and the second portion 12 can each be a hollow structure with one end open, with the open side of the first portion 11 overlapping the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0066] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 20 may be housed within the housing 10. Alternatively, the battery 100 may be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid connection to form a battery module, which is then connected in series, in parallel, or in a hybrid connection to form a complete battery module, and then housed within the housing 10. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0067] Each battery cell 20 may be a secondary battery or a primary battery, and may also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0068] In conjunction with the figures shown in Figures 3-9, an embodiment of the present application provides a battery cell 20, including a shell 22, an electrode assembly 23, a breathable valve assembly 212 and a protective member 213: the shell 22 has a accommodating cavity 222, the shell 22 includes a first wall 211, the first wall 211 has a first surface 2111 and a second surface 2112 opposite to 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, the first exhaust hole 2113 passes through the first surface 2111 and the second surface 2112; the electrode assembly 23 is accommodated in the accommodating cavity 222; the breathable valve assembly 212 is connected to the first wall 211 and covers the first exhaust hole 2113; the protective member 213 is detachably connected to the second surface 2112 and covers the breathable valve assembly 212.

[0069] The housing 22 can have a variety of shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, and the like. Specifically, the shape of the housing 22 can be determined based on the specific shape and size of the electrode assembly 23. The housing 22 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, and the like, and this embodiment of the present application does not impose any particular limitation thereto. In some examples, the housing 22 can have a first insulating film layer 22a disposed on the inside and a second insulating film layer 22b disposed on the outside.

[0070] The electrode assembly 23 is a component where electrochemical reactions occur in the battery 100. One or more electrode assemblies 23 may be contained within the housing 22.

[0071] The first wall 211 of this embodiment can be a side wall or bottom wall of the shell 22, or can be the end cover body of the end cover assembly 21 in the shell 22. The following description will take the first wall 211 as the end cover body of the end cover assembly 21 as an example.

[0072] The end cap assembly 21 refers to a component that covers the opening 221 of the outer shell 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 outer shell 22 to match the opening 221. Optionally, the end cap assembly 21 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap assembly 21 is not easily deformed when squeezed or collided, so that the battery cell 20 can 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 the adapter 24 for outputting or inputting electrical energy of the battery cell 20.

[0073] The first wall 211 of this embodiment can be made of a material with a certain degree of hardness and strength (such as aluminum alloy). The first wall 211 has a first surface 2111 and a second surface 2112 that are opposite to each other. After the battery cell 20 is assembled, 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 as shown, or other shapes, which can be determined by the shape of the opening 221 of the outer shell 22 of the battery cell 20, which are not listed in this embodiment.

[0074] Electrode terminals 21a are installed at both ends of the first wall 211, and the aforementioned first exhaust hole 2113 is provided between the two electrode terminals 21a. The breathable valve assembly 212 is connected to the first wall 211 and covers the first exhaust hole 2113. The breathable valve assembly 212 can be connected to the first surface 2111.

[0075] When the internal pressure of the battery cell 20 increases, part of the gas in the battery cell 20 can be discharged from the breathable valve assembly 212 along the first direction X to the first exhaust hole 2113, and finally discharged from the first exhaust hole 2113 to the outside of the battery cell 20 to reduce the air pressure inside the battery cell 20, thereby reducing the risk of the battery 100 being unusable due to the opening of the pressure relief mechanism 215 due to excessive air pressure, which is beneficial to improving the stability and service life of the battery cell 20.

[0076] 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 can be removed after the battery cell 20 is assembled and before the insulating patch 216 is installed.

[0077] In some examples, the protective member 213 is bonded, snap-fitted, or connected to the second surface 2112 via a connector, which is detachably connected to the first wall 211 and the protective member 213. The connector can be a screw or other structure.

[0078] By providing a removable protective member 213 to protect the first exhaust hole 2113, the possibility of foreign matter and impurities entering the breathable valve assembly 212 and affecting the exhaust function during the production of the battery cell 20 is reduced, the reliability of the breathable valve assembly 212 is improved, and the protective member 213 can be directly removed when necessary to facilitate the subsequent attachment of the insulating patch 216.

[0079] In some examples with reference to Figures 6, 10 and 11, optionally, the protective member 213 is bonded to the first surface 2111, and 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 bonded to the second surface 2112.

[0080] 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 adhesive layer 2132 is used to bond the protective member 213 of this embodiment to the second surface 2112. 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, thereby improving the installation efficiency and removal efficiency of the protective member 213.

[0081] In some examples, optionally, the adhesive layer 2132 of this embodiment is disposed around the first exhaust hole 2113 .

[0082] 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 .

[0083] As shown in FIG. 11 , in some examples, optionally, the protective layer 2131 of this embodiment includes a main body 21312 and an extension ear 21313 , wherein the main body 21312 is connected to the second surface 2112 , and the extension ear 21313 is connected to the edge of the main body 21312 and has a gap 21314 with the second surface 2112 .

[0084] 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 .

[0085] The extension ear 21313 and the protective layer 2131 can be connected as a whole by welding or bonding, or they can be directly formed as a whole during processing. The shape of the extension ear 21313 can be approximately rectangular, and of course it can also be other shapes such as circular, triangular, etc., which are not listed one by one in this embodiment.

[0086] In some examples, optionally, the size of the gap 21314 in the first direction X gradually increases from the end where the extension ear 21313 is connected to the body 21312 to the end where the extension ear 21313 is away from the body 21312, and the first direction X is the arrangement direction from the first surface 2111 to the second surface.

[0087] 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, further improving the removal efficiency of the protective member.

[0088] In some examples, optionally, the protective member 213 of this embodiment is provided with a through hole 21311 , and the through hole 21311 passes through the protective member 213 along a first direction X, where the first direction X is an arrangement direction from the first surface 2111 to the second surface.

[0089] Through hole 21311 connects first vent hole 2113 and vent valve assembly 212, facilitating testing of the performance of vent valve assembly 212 of this embodiment before installing insulating patch 216. Furthermore, when adhesive layer 2132 of this embodiment surrounds first vent hole 2113, it does not obstruct the first vent hole 2113, further facilitating testing of the performance of vent valve assembly 212 of this embodiment.

[0090] In some examples, optionally, the maximum dimension of the through hole 21311 of this embodiment along the second direction Y is smaller than the maximum dimension of the first exhaust hole 2113 along the second direction Y, and the second direction Y is parallel to the first surface 2111 and parallel to or intersecting with the extension direction of the first wall 211.

[0091] That is, the aperture of the through hole 21311 in this embodiment is smaller than the aperture of the first exhaust hole 2113. For example, the aperture of the through hole 21311 is smaller 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 to foreign matter and impurities from the outside. Therefore, the possibility of foreign matter and impurities directly passing through the through hole 21311 into the first exhaust hole 2113 can be reduced.

[0092] In some examples, optionally, the maximum dimension of the through hole 21311 of this embodiment along the first direction X is less than or equal to 1 mm.

[0093] For example, the aperture of the through hole 21311 can be 1 mm, 0.5 mm, 0.1 mm, etc. Designing the maximum size of the through hole 21311 in the first direction X to be within the above numerical range can further reduce the possibility of foreign matter and impurities entering the through hole 21311.

[0094] As shown in Figures 6, 8, and 12, in some examples, the breathable valve assembly 212 of this embodiment optionally 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 vent hole 21211. The second vent hole 21211 passes through the first valve body 2121 along a first direction X, which is the direction from the first surface 2111 to the second surface. 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 vent hole 21211.

[0095] The first valve body 2121 can be in the shape of a disc as shown in the figure, and its material can be selected from plastic or metal. The breathable membrane layer 2122 is connected to the surface of the first valve body 2121 facing away from the first wall 211. The shape of the breathable membrane layer 2122 and the first valve body 2121 are both designed to be sheet-like, which can reduce the size of the entire breathable valve assembly 212 in the first direction X.

[0096] The breathable membrane layer 2122 allows gas to pass through from the first surface 2111 to the second surface 2112 in FIG. 6 . The breathable membrane layer 2122 may be made of materials such as polypropylene, polyethylene, polytetrafluoroethylene, polyester, and polyurethane.

[0097] In this embodiment, the breathable valve assembly 212 is designed to include a first valve body 2121 and a breathable membrane layer 2122, which not only realizes the exhaust function, but also has a smaller overall size of the breathable valve assembly 212 in the first direction X under this structure, thereby reducing the impact of the breathable valve assembly 212 on the installation of other auxiliary structures of the end cover assembly 21 (such as the insulating member 214).

[0098] In some examples, optionally, the first surface of this embodiment is provided with a first groove 21111 and a second groove 21112 that are interconnected in sequence along the first direction X, the second groove 21112 is connected to the first exhaust hole 2113, and 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, and the second direction Y is parallel to the first surface 2111 and parallel to or intersects with the extension direction of the first wall 211; the first valve body 2121 is installed in the first groove 21111.

[0099] By setting the first groove 21111 and the second groove 21112, the first valve body 2121 located in the first groove 21111 is connected to the first exhaust hole 2113 through the second groove 21112, and the sizes of the first valve body 2121, the second groove 21112 and the first exhaust hole 2113 in the second direction gradually decrease, thereby reducing the risk of gas directly entering the first exhaust hole 2113 from the larger first valve body 2121 and generating gas turbulence, which is conducive to the centralized discharge of gas.

[0100] In some examples, optionally, there are multiple second vent holes 21211 in this embodiment. The multiple second vent holes 21211 facilitate the discharge of gas inside the battery cell 20 .

[0101] In some embodiments, one of the plurality of second exhaust holes 21211 is disposed in the middle of the first valve body 2121 , and the remaining second exhaust holes 21211 are disposed around the second exhaust hole 21211 in the middle of the first valve body 2121 .

[0102] The distance between two adjacent second exhaust holes 21211 is smaller 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 of this embodiment is a disc-shaped structure as shown in the figure, the middle of the first valve body 2121 refers to the center position of the first valve body 2121.

[0103] By arranging a plurality of peripheral second exhaust holes 21211 around the central second exhaust hole 21211 , the arrangement density of the second exhaust holes 21211 can be increased to a certain extent, which is more conducive to the communication between the second exhaust holes 21211 and the first exhaust holes 2113 .

[0104] Again referring to Figures 6 and 7 , in some examples, optionally, the end cover assembly 21 of this embodiment further includes an insulating member 214 , which is connected to the first wall 211 , and the insulating member 214 is provided with a third exhaust hole 2141 , and the air valve assembly 212 is located between the first wall 211 and the insulating member 214 , and covers the third exhaust hole 2141 .

[0105] The insulating member 214 may be made of insulating materials such as plastic and rubber. The insulating member 214 is connected to the first surface 2111 of the first wall 211 by a connecting post as shown in the figure. The connecting post and the first wall 211 may be plug-fitted or threaded.

[0106] The insulating member 214 is provided with a vent structure 2142 disposed opposite the first wall 211 in the first direction X. This vent structure 2142 is configured to cooperate with the pressure relief mechanism 215 to achieve pressure relief when the internal pressure reaches a threshold. Furthermore, to facilitate venting when the internal pressure rises but does not reach the threshold for activating the pressure relief mechanism 215, the insulating member 214 of this embodiment is provided with a third vent hole 2141 that communicates with the first vent hole 2113 via the vent valve assembly 212.

[0107] 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, the breathable valve assembly 212 of this embodiment is arranged between the first wall 211 and the insulating member 214, which can improve the stability of the breathable valve assembly 212 after installation.

[0108] In some examples, optionally, a projection of the second exhaust hole 21211 of this embodiment along the first direction X on the insulating member 214 is located within the third exhaust hole 2141 .

[0109] The projection of the second exhaust hole 21211 on the insulating part 214 along the first direction X can be understood as the projection of the plane on the side of the insulating part 214 facing the first wall 211, and it cannot be understood that the projection must be on a certain physical structure of the insulating part 214, because the existence of the third exhaust hole 2141 may not be able to directly form a projection.

[0110] This structure makes the aperture of the third exhaust hole 2141 larger than or equal to the aperture of the second exhaust hole 21211, which is conducive to the gas in the battery cell 20 entering the ventilation valve assembly 212 through the third exhaust hole 2141, thereby improving the exhaust efficiency.

[0111] In some examples, optionally, the maximum dimension a of the third exhaust hole 2141 along the second direction Y can be greater than the maximum dimension b of the first exhaust hole 2113 along the first direction X, and the second direction Y is parallel to the first surface 2111 and parallel to or intersecting with the extension direction of the first wall 211.

[0112] That is, the aperture of the third exhaust hole 2141 is larger than the aperture of the aforementioned first exhaust hole 2113. For example, the aperture of the third exhaust hole 2141 is 2-10 times the aperture of the first exhaust hole 2113. The larger third exhaust hole 2141 is conducive to the gas in the battery cell 20 entering the first exhaust hole 2113 through the third exhaust hole 2141 and the breathable valve assembly 212, which can improve the exhaust efficiency.

[0113] Referring again to FIG. 9 , in some examples, optionally, the end cover assembly 21 further includes a pressure relief mechanism 215 , a fourth exhaust hole 2114 is defined in the first wall 211 , and the pressure relief mechanism 215 is connected to the first surface 2111 and seals the fourth exhaust hole 2114 .

[0114] The pressure relief mechanism 215 refers to an element or component that is activated to release the internal pressure or temperature when the internal pressure or temperature of the battery cell reaches a predetermined threshold. The threshold design varies according to different design requirements. The threshold may depend on the material of one or more of the positive electrode plate, negative electrode plate, electrolyte and separator in the battery cell. The pressure relief mechanism 215 can take the form of an explosion-proof valve, an air valve, a pressure relief valve or a 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 executes an action or the weak structure provided in the pressure relief mechanism is destroyed, thereby forming an opening or channel for the internal pressure or temperature to be released. The pressure relief mechanism 215 can be used to discharge gas when the internal pressure of the battery cell 20 is too high, reducing the risk of the battery cell 20 exploding due to excessive internal air pressure.

[0115] Referring to Figures 3-12 , an embodiment of the present application provides a battery cell 100, comprising a housing 22, an electrode assembly 23, a vent assembly 212, and a protective member 213. The housing 22 has a housing cavity 222 and includes a first wall 211. The first wall 211 has a first surface 2111 and a second surface 2112 facing each other, with the second surface 2112 facing the exterior of the battery cell 100. The first wall 211 defines a first vent hole 2113, which extends through the first and second surfaces 2111 and 2112. The electrode assembly 23 is accommodated within the housing cavity 222. The vent assembly 212 is connected to the first wall 211 and covers the first vent hole 2113. The protective member 213 is removably connected to the second surface 2112 and covers the vent assembly 212. The protective member 213 is bonded, snap-fitted, or connected to the second surface 2112 via a connector, which is removably connected to the first wall 211 and the protective member 213, respectively. The protective member 213 is bonded to the second surface 2112 and 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 bonded to the second surface 2112. The adhesive layer 2132 is disposed around the first vent 2113. The protective layer 2131 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 defines a gap 21314 with the second surface 2112. The gap 21314 gradually increases in size in a first direction X from the end of the extension ear 21313 connected to the main body 21312 to the end of the extension ear 21313 facing away from the main body 21312. The first direction X is the direction of arrangement from the first surface 2111 to the second surface. The protective member 213 defines a through hole 21311 extending through the protective member 213 along a first direction X, which is the direction of arrangement from the first surface 2111 to the second surface. The maximum dimension of the through hole 21311 along a second direction Y is smaller than the maximum dimension of the first exhaust holes 2113 along the second direction Y. The second direction Y is parallel to the first surface 2111 and parallel to or intersecting the extension direction of the first wall 211. The maximum dimension of the through hole 21311 along the second direction Y is less than or equal to 1 mm. The breathable 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 passes through the first valve body 2121 along a first direction X and is connected to the first exhaust hole 2113. The first direction X is the arrangement direction from the first surface 2111 to the second surface; the breathable membrane layer 2122 is connected to the side of the first valve body 2121 away from the first wall 211 and covers the second exhaust hole 21211.The first surface 2111 is formed with a first groove 21111 and a second groove 21112, which intersect each other, in sequence along a first direction X. The second groove 21112 is connected to the first vent 2113. In a 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 vent 2113. The second direction Y is parallel to the first surface 2111 and parallel to or intersects the extension direction of the first wall 211. The first valve body 2121 is at least partially mounted within the first groove 21111. There are multiple second vents 21211. One of the multiple second vents 21211 is located in the center of the first valve body 2121, and the remaining second vents 21211 are arranged around the second vent 21211 located in the center of the first valve body 2121. The battery cell 100 also includes an insulating member 214 connected to the first wall 211. The insulating member 214 defines a third vent hole 2141. The vent valve assembly 212 is located between the first wall 211 and the insulating member 214 and communicates with the third vent hole 2141. The projection of the second vent hole 21211 onto the insulating member 214 along the first direction X is located within the third vent hole 2141. The battery cell 100 also includes a pressure relief mechanism 215. A fourth vent hole 2114 is defined in the first wall 211 and is sealed by the pressure relief mechanism 215. The first wall 211 is a wall of the end cap body or housing 22 of the end cap assembly 21.

[0116] Finally, in conjunction with FIG. 13 , based on the above-mentioned battery cell 20 , battery 100 , and electrical device, an embodiment of the present application further provides a method for producing a battery cell 100 , comprising the following steps:

[0117] A protective member 213 is provided over the first vent hole 2113 of the battery 100. The first vent hole 2113 is connected to a vent valve assembly 212 for discharging gas from the interior of the battery 100 to the outside.

[0118] Tear off the protective piece 213.

[0119] In some examples, before removing the protective member 213 , a sealing pin welding process is optionally performed on the battery 100 . The sealing pin is used to seal the injection hole and can be made of insulating or non-insulating material. The sealing pin can be welded to the end cap assembly 21 .

[0120] In some examples, after the protective member 213 is removed, the process further includes coating the battery 100 with an insulating film, which may be a blue film.

[0121] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0122] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for the intermediate technical features. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application.

Claims

1. A battery cell, wherein: include: A housing having a receiving cavity, the housing comprising a first wall, the first wall having a first surface and a second surface opposite to each other, the second surface facing the outside of the battery cell, the first wall being provided with a first exhaust hole, the first exhaust hole penetrating the first surface and the second surface; An electrode assembly, contained in the containing cavity; a breathable valve assembly connected to the first wall and covering the first exhaust hole; as well as A protective member is detachably connected to the second surface and covers the breathable valve assembly.

2. The battery cell according to claim 1, wherein: The protective member is bonded, snap-connected or connected to the second surface via a connecting member, and the connecting member is detachably connected to the first wall and the protective member respectively.

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

4. The battery cell according to claim 3, wherein: The adhesive layer is disposed around the first exhaust hole.

5. The battery cell according to claim 3 or 4, wherein: The protective layer includes a body and an extension ear, wherein the body is connected to the second surface, and the extension ear is connected to an edge of the body and has a gap with the second surface.

6. The battery cell according to claim 5, wherein: From one end of the extension ear connected to the body to the end of the extension ear away from the body, the size of the gap in a first direction gradually increases, and the first direction is the arrangement direction from the first surface to the second surface.

7. The battery cell according to claim 3, wherein: The protection layer is provided with a through hole, and the through hole penetrates the protection member along a first direction, where the first direction is an arrangement direction from the first surface to the second surface.

8. The battery cell according to claim 7, wherein: 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. The second direction is parallel to the first surface and parallel to or intersects with the extension direction of the first wall.

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

10. The battery cell according to any one of claims 1 to 9, wherein: The breathable valve assembly comprises: a first valve body connected to the first wall and provided with a second exhaust hole, the second exhaust hole penetrating the first valve body along a first direction and communicating with the first exhaust hole, the first direction being an arrangement direction from the first surface to the second surface; The breathable membrane layer is connected to a side of the first valve body facing away from the first wall and covers the second exhaust hole.

11. The battery cell according to claim 10, wherein: The first surface is provided with a first groove and a second groove which are interconnected in sequence along the first direction, the second groove is connected to the first exhaust hole, in the second direction, the maximum dimension of the first groove is larger than the maximum dimension of the second groove, the maximum dimension of the second groove is larger than the maximum dimension of the first exhaust hole, the second direction is parallel to the first surface, and is parallel to or intersects with the extension direction of the first wall; the first valve body is at least partially installed in the first groove.

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

13. The battery cell according to claim 12, wherein: One of the plurality of 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 connected to the first wall. The insulating member is provided with a third exhaust hole. The air-permeable 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: A projection of the second exhaust hole on the insulating member along the first direction is located inside the third exhaust hole.

16. The battery cell according to any one of claims 1 to 15, wherein: The battery cell further includes a pressure relief mechanism, a fourth exhaust hole is formed in the first wall, and the pressure relief mechanism seals the fourth exhaust hole.

17. The battery cell according to any one of claims 1 to 16, wherein: The first wall is a wall of an end cap body or housing of the end cap assembly.

18. A battery, wherein: Comprising the battery cell as claimed in claim 17.

19. An electrical device, wherein: Comprising a battery as claimed in claim 18, the battery is used to provide electrical energy.

20. A method for producing a battery cell, wherein: The following steps are involved: A protective member is covered at a first exhaust hole of the battery cell, wherein the first exhaust hole is connected to a vent valve assembly, and the vent valve assembly is used to discharge gas from the inside of the battery cell to the outside; Remove the protective piece.

21. The method for producing a battery cell according to claim 20, wherein: Before the protective member is removed, a sealing nail welding process is also performed on the battery cell.

22. The method for producing a battery cell according to claim 20 or 21, wherein: After the protective member is removed, the process further includes coating the battery cell with an insulating film.

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