End cover assembly, battery monomer, battery and electric device

Abstract

The invention provides an end cover assembly, a battery monomer, a battery and a power utilization device, the end cover assembly is used for the battery monomer, the battery monomer comprises an electrode assembly, the end cover assembly comprises: a cover plate, the cover plate is provided with an accommodating hole extending along a first direction; the ventilation assembly is arranged in the accommodating hole and connected with the cover plate, and the ventilation assembly is used for discharging gas in the battery monomers; the identification part is arranged on the ventilation assembly and located on the side, away from the electrode assembly, of the ventilation assembly in the first direction. The arrangement of the identification part on the end cover assembly can meet the tracking of related parameters in the manufacturing and using processes of the battery monomer.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to an end cover assembly, a battery cell, a battery and an electrical device. Background Art

[0002] Batteries are widely used in electronic devices, such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes and power tools, etc.

[0003] In the development of battery cell technology, in addition to improving the performance of battery cells, there are also certain requirements for tracking the relevant parameters of battery cells during manufacturing and use, which provides an important basis for subsequent analysis of battery cell performance and other related issues. However, how to meet the tracking of relevant parameters of battery cells during manufacturing and use is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0004] An embodiment of the present application provides an end cap assembly, a battery cell, a battery, and an electrical device. The arrangement of the identification portion on the end cap assembly can meet the needs of tracking relevant parameters of the battery cell during manufacturing and use.

[0005] In a first aspect, the present application provides an end cap assembly for a battery cell, wherein the battery cell includes an electrode assembly, and the end cap assembly includes: a cover plate, wherein the cover plate is provided with a receiving hole extending along a first direction; a vent assembly, which is arranged in the receiving hole and connected to the cover plate, and the vent assembly is used to discharge the gas inside the battery cell; and an identification portion, which is arranged in the vent assembly and is located on a side of the vent assembly that is away from the electrode assembly in the first direction.

[0006] An end cap assembly provided in one embodiment of the present application includes a cover plate, a vent assembly and an identification part. The vent assembly can be used to discharge the gas inside the battery cell and reduce the probability of thermal runaway of the battery cell. Since the identification part is arranged on the vent assembly and is located on the side of the vent assembly away from the electrode assembly in the first direction, it can provide space for the arrangement of the identification part and prevent the electrolyte inside the battery cell from corroding the identification part during liquid injection and spraying, resulting in unclear identification part. It is conducive to the identification of the battery cell where the end cap assembly is located, and meets the tracking of relevant parameters of the battery cell during manufacturing and use.

[0007] In some embodiments, the orthographic projection of the identification portion in the first direction is a first pattern, and the first pattern includes at least one of a barcode, a two-dimensional code, and text.

[0008] By making the positive projection of the identification part in the first direction a first pattern, the first pattern includes at least one of a barcode, a QR code and text, which facilitates the setting of the identification part on the breathable component and at the same time can avoid the setting of the identification part affecting the strength and breathability of the breathable component.

[0009] In some embodiments, the identification portion includes at least one of a printed pattern and an etched pattern disposed on the breathable component.

[0010] By making the identification part include at least one of a printed pattern and an etched pattern arranged on the breathable component, the identification part can be formed on the breathable component by using a printing or etching process, which is simple to operate and will not affect the breathability and strength of the breathable component.

[0011] In some embodiments, the breathable component includes a fixing, a breathable film layer and a protective film layer; along a first direction, the breathable film layer is used to discharge the gas inside the battery cell, the fixing is used to connect the cover plate to fix the breathable film layer, the protective film layer is connected to the cover plate and covers the fixing, and the identification portion is set on at least one of the fixing and the protective film layer.

[0012] By providing a protective film layer, the fixing parts can be protected and the probability of scratches, wear, moisture corrosion and the like of the specified parts can be reduced. In addition, the provision of the protective film layer can also provide more options for the location and setting method of the identification part, which is conducive to the implementation of the scheme of setting the identification part in the breathable component.

[0013] In some embodiments, the breathable component includes a fixing member and a breathable film layer, the breathable film layer is used to discharge the gas inside the battery cell, the fixing member is used to connect the cover plate to fix the breathable film layer, and the identification portion is set on the fixing member.

[0014] By making the vent assembly adopt the above-mentioned structural form, the gas discharge requirements of the end cap assembly when used in the battery cell can be guaranteed, and thermal runaway of the battery cell can be avoided. At the same time, the fixing piece can provide a setting space for the identification part, reduce the risk of the identification part being corroded by the electrolyte, and meet the tracking of relevant parameters of the battery cell during the manufacturing and use process.

[0015] In some embodiments, the fixing member is a plate-like structure covering the accommodating hole, the fixing member is provided with air holes, the air permeable film layer covers the air permeable holes in the first direction, and the identification portion is at least partially arranged on the side of the fixing member away from the air permeable film layer in the first direction.

[0016] The end cap assembly provided in one embodiment of the present application can ensure the installation and support of the breathable membrane layer by the fixing member through the above-mentioned arrangement, and ensure the breathability requirements. In addition, the fixing member in the form of a plate-like structure is conducive to the setting of the identification part. Improving the recognizability of the identification part is conducive to tracking the relevant parameters of the battery cell where the end cap assembly is located during the manufacturing and use process.

[0017] In some embodiments, the identification portion includes an etched pattern disposed on a surface of the fixing element on one side facing away from the breathable membrane layer in the first direction.

[0018] An end cap assembly provided by an embodiment of the present application facilitates the formation of the identification portion on the fixing member by making the identification portion include an etched pattern arranged on the surface of a side of the fixing member that is away from the breathable membrane layer in a first direction, and can ensure the durability of the pattern of the identification portion on the fixing member, which is beneficial to the tracking of relevant parameters of the battery cell during the manufacturing and use processes.

[0019] In some embodiments, there are multiple air holes and they are spaced apart on the fixing member, a support portion is formed between two adjacent air holes, the support portion is spaced apart from the identification portion, and the air permeable membrane layer is at least partially stacked with the support portion along the first direction.

[0020] By making the number of air holes more than two, the exhaust requirements can be met. At the same time, the size of each air hole can be made moderate to avoid the air hole diameter being too large to affect the strength of the fixing, and to avoid the air hole diameter being too small to affect the ventilation efficiency. In addition, the support portion can be attached to the breathable film layer. When the gas inside the battery cell acts on the breathable film layer during the process of being discharged to the outside of the battery cell through the breathable film layer, the support portion can provide the breathable film layer with a force opposite to the internal pressure of the battery cell, thereby reducing the deformation of the breathable film layer, improving the overall internal pressure resistance of the breathable component, and thus improving the safety of the battery cell. At the same time, the support portion and the identification portion are spaced apart, so that the identification portion can be set in a complete area of ​​the fixing, ensuring the integrity and continuity of the first pattern formed by its orthographic projection in the first direction, which is convenient for identifying the identification portion.

[0021] In some embodiments, the diameter of the air pores ranges from 0.5 mm to 3 mm.

[0022] By setting the diameter of the air holes to a range of 0.5mm-3mm, the exhaust requirements of the air holes can be guaranteed, which is conducive to setting the number of air holes to more than two, and it can also avoid the air holes having too large diameters that affect the strength of the fixings, and can also avoid the air holes having too small diameters that affect the ventilation efficiency.

[0023] In some embodiments, the number of the air-permeable hole is one, and along the radial direction of the receiving hole, the minimum vertical distance between the outer edge of the air-permeable membrane layer and the hole wall of the air-permeable hole is D, and the value range of D is 1 mm-6 mm;

[0024] Alternatively, there are multiple air holes, and along the radial direction of the accommodating hole, there are multiple minimum vertical distances between the outer edge of the air permeable membrane layer and the hole walls of the multiple air permeable holes, the minimum value of the multiple minimum vertical distances is D, and the value range of D is 1mm-6mm.

[0025] The battery cell provided in one embodiment of the present application can, through the above-mentioned arrangement, make the distance between the hole wall of the air hole and the edge of the air permeable membrane layer moderate regardless of whether one or more air permeable membrane layers are used, thereby reducing the probability of affecting the bonding strength between the air permeable membrane layer and the fixing part due to too small a distance, and at the same time reducing the probability of affecting the ventilation effect due to reducing the number of air holes due to too large a distance.

[0026] In some embodiments, the identification portion includes a printed pattern disposed on the protective film.

[0027] By making the identification part include a printed pattern arranged on the protective film layer, it is convenient to form the identification part on the protective film layer, and can ensure the durability of the pattern of the identification part on the protective film layer, which is convenient for tracking relevant parameters of the battery cell during manufacturing and use.

[0028] In some embodiments, an annular gasket is provided on the cover plate. Along the first direction, the orthographic projection of the gasket is arranged around the orthographic projection of the fixing member. The protective film layer is supported on the side of the gasket away from the cover plate and a gap is formed between the gasket and the cover plate. The gasket is disconnected and provided with a notch along its own annular extension direction.

[0029] The end cover assembly provided in one embodiment of the present application can, through the above-mentioned arrangement, ensure that the protective film layer covers the fixing member to ensure the protection of the fixing member. At the same time, the arrangement of the pad can support the protective film layer to a certain height in the first direction, so that the gas flowing through the breathable film layer can be smoothly discharged from the gap and the notch, thereby ensuring the exhaust effect.

[0030] In some embodiments, the hardness of the fixing member is less than the hardness of the cover plate, and the fixing member and the cover plate are both made of aluminum alloy.

[0031] Through the above arrangement, when the logo part is set on the fixing part, since the fixing part is made of a material with relatively low hardness, the processing and manufacturing properties of the logo part can be improved, and the clarity of the logo part can be improved. At the same time, the brightness of the fixing part can be reduced, so that the reflection effect of the logo part can be reduced when it is identified.

[0032] In some embodiments, the aluminum alloy of the fixing part includes the following components in mass percentage: aluminum ≥ 99.6%, copper ≤ 0.05%, iron ≤ 0.35%, magnesium ≤ 0.03%, manganese ≤ 0.03%, silicon ≤ 0.25%, titanium ≤ 0.03%, vanadium ≤ 0.05%, zinc ≤ 0.05%, and other single elements ≤ 0.03%; the aluminum alloy of the cover plate includes the following components in mass percentage: aluminum ≥ 96.7%, 0.05% ≤ copper ≤ 0.2%, iron ≤ 0.7%, manganese ≤ 1.5%, silicon ≤ 0.6%, zinc ≤ 0.1%, other single element components ≤ 0.05%, and the total composition of other elements ≤ 0.15%.

[0033] Through the above arrangement, it is possible to ensure that the hardness of the fixing member is less than the hardness of the cover plate, and it is also convenient to form the identification portion on the fixing member.

[0034] In some embodiments, along the radial direction of the accommodating hole, a first vertical distance between an outer edge of the breathable membrane layer and an outer edge of the fixing member is d, and the value range of d is 1 mm-5 mm.

[0035] By setting the value range of d to 1mm-5mm, the value of d can be made moderate, avoiding the value of d being too small, so that when the fixing part is connected to the cover plate by welding or other methods, the residual heat of laser welding will melt the breathable membrane. At the same time, it can also avoid the value of d being too large, reducing the number of air holes and affecting the ventilation effect.

[0036] In some embodiments, along the first direction, the accommodating hole includes a first hole segment, a second hole segment and a third hole segment, the radial dimension of the first hole segment is larger than the radial dimension of the second hole segment, a first step surface is connected between the first hole segment and the second hole segment, the radial dimension of the second hole segment is larger than the radial dimension of the third hole segment, the fixing part is supported on the first step surface, and the breathable membrane layer is located in the second hole segment.

[0037] An end cap assembly provided by an embodiment of the present application has a receiving hole adopting the above-mentioned structural form, so that the air hole can accommodate the air permeable assembly and ensure the installation and support of the air permeable assembly, thereby ensuring the air permeability effect and improving the safety performance of the battery to which the end cap assembly is applied.

[0038] In a second aspect, the present application provides a battery cell, comprising: a shell having an inner cavity and an opening connected to the inner cavity; an electrode assembly disposed in the inner cavity; and the above-mentioned end cover assembly, which is disposed to close the opening and is connected to the shell.

[0039] In a third aspect, the present application provides a battery, comprising the above-mentioned battery cell.

[0040] In a fourth aspect, the present application provides an electrical device, comprising the above-mentioned battery, and the battery is used to provide electrical energy.

[0041] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0043] Figure 1 is a structural schematic diagram of a vehicle provided by an embodiment of the present application;

[0044] Figure 2 is a schematic diagram of the structure of a battery pack provided in one embodiment of the present application;

[0045] Figure 3 is a schematic diagram of the exploded structure of a battery cell provided in one embodiment of the present application;

[0046] Figure 4 It is a structural schematic diagram of an end cover assembly provided by an embodiment of the present application;

[0047] Figure 5 yes Figure 4 The cross-sectional view along the AA direction;

[0048] Figure 6 yes Figure 5 A partial enlarged view of point B in the middle;

[0049] Figure 7 is a partial exploded view of an end cap assembly provided in one embodiment of the present application;

[0050] Figure 8 is a structural schematic diagram of an end cover assembly provided by another embodiment of the present application;

[0051] Fig. 9 is a structural schematic diagram of an end cover assembly provided by another embodiment of the present application;

[0052] Fig.10 yes Fig. 9 Cross-sectional view along CC direction;

[0053] Fig.11 yes Fig.10 A partial enlarged view of point D in the middle;

[0054] Fig.12It is a schematic diagram of the structure of a breathable component provided in one embodiment of the present application.

[0055] The reference numerals in the specific implementation manner are as follows:

[0056] 1000-Vehicles;

[0057] 100-battery; 200-controller; 300-motor;

[0058] 10-box; 11-first part; 12-second part;

[0059] 20-battery cell;

[0060] 21-housing;

[0061] 22-electrode assembly; 221-positive electrode tab; 222-negative electrode tab;

[0062] 23-end cover assembly;

[0063] 231-cover plate; 2311-accommodating hole; 2311a-first hole section; 2311b-second hole section; 2311c-third hole section; 2311d-first step surface;

[0064] 232-ventilation component; 2321-fixing member; 2321a-ventilation hole; 2321b-supporting part; 2322-ventilation film layer; 2323-protective film layer;

[0065] 233 - identification part; 234 - pad; 235 - positive electrode terminal; 236 - negative electrode terminal;

[0066] X-first direction; Y-radial direction. DETAILED DESCRIPTION

[0067] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0068] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in an embodiment of the present application should have the common meanings understood by technicians in the field to which an embodiment of the present application belongs.

[0069] In the description of an embodiment of the present application, the orientation or position relationship indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" are based on the orientation or position relationship shown in the accompanying drawings and are only for the convenience of describing an embodiment of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on an embodiment of the present application.

[0070] In addition, the technical terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. In the description of an embodiment of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0071] In the description of an embodiment of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in an embodiment of the present application can be understood according to the specific circumstances.

[0072] In the description of an embodiment of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0073] At present, from the perspective of market development, 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 stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0074] 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 or a magnesium-ion battery cell, etc., and this is not limited in one embodiment of the present application. The battery cell may be cylindrical, flat, rectangular or other shapes, etc., and this is not limited in one embodiment of the present application.

[0075] The battery cell includes a shell, an end cap assembly, an electrode assembly and an electrolyte. 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 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 current collector and a positive electrode ear connected to the positive current collector, the positive current collector is coated with a positive active material layer, and the positive electrode ear is not coated with a positive active material layer. Taking lithium-ion batteries as an example, the material of the positive current collector can be aluminum, the positive active material layer includes a positive active material, and the positive 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, the negative active material layer is coated on the surface of the negative current collector; the negative current collector includes a negative current collector and a negative electrode tab connected to the negative current collector, the negative current collector is coated with the negative active material layer, and the negative electrode tab is not coated with the negative active material layer. The material of the negative current collector can be copper, 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.

[0076] In the development of battery cell technology, in addition to improving the performance of battery cells, there are also certain requirements for tracking the relevant parameters of battery cells during manufacturing and use, which provides an important basis for subsequent related analysis such as the performance of battery cells.

[0077] In the related art, an identification portion is set between the electrode terminal and the explosion-proof valve of the end cover assembly. This setting method makes it easy for the electrolyte to corrode the identification portion after the electrolyte is injected and sprayed when the end cover assembly is used in a battery cell, resulting in problems such as incomplete display of the identification portion, and thus failing to meet the tracking of relevant parameters of the battery cell during the manufacturing and use process.

[0078] In order to alleviate the problem of being unable to track the relevant parameters of battery cells during manufacturing and use, the applicant has discovered that the position of the identification portion can be adjusted to ensure the tracking requirements of the relevant parameters of the battery cells during manufacturing and use by reducing the risk of the identification portion being corroded by the electrolyte.

[0079] Based on the above considerations, in order to solve the problem of tracking relevant parameters of the battery cell during manufacturing and use caused by corrosion of the identification part, an end cap assembly of the battery cell is designed, the end cap assembly includes a cover plate, a vent assembly and an identification part, and the cover plate is provided with a receiving hole extending along a first direction. The vent assembly is arranged in the receiving hole and connected to the cover plate, and the vent assembly is used to discharge the gas inside the battery cell. The identification part is arranged in the vent assembly and is located on the side of the vent assembly away from the electrode assembly in the first direction.

[0080] In such an end cap assembly, since the identification portion is arranged on the breathable assembly and is located on the side of the breathable assembly away from the electrode assembly in the first direction, it can not only provide space for the arrangement of the identification portion, but also prevent the electrolyte inside the battery cell from corroding the identification portion during liquid injection and spraying, resulting in unclear identification portion. This is beneficial to the identification of the battery cell where the end cap assembly is located and meets the tracking of relevant parameters of the battery cell during manufacturing and use.

[0081] The technical solution described in one embodiment of the present application is applicable to a battery cell, a battery, and an electrical device using the battery.

[0082] The electrical device may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, and the like; the spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toy includes a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and an electric tool for railways, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, and the like. One embodiment of the present application does not impose any special restrictions on the above-mentioned electrical devices.

[0083] It should be understood that the technical solution described in one embodiment of the present application is not limited to the batteries and electrical equipment described above, but can also be applied to all batteries including a box and electrical equipment using the battery. However, for the sake of simplicity, the following embodiments are described using electric vehicles as examples.

[0084] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of the present application. A battery 100 is disposed inside the vehicle 1000. The battery 100 may be disposed at the bottom, head, or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000. For example, the battery 100 may be used as an operating power source for the vehicle 1000.

[0085] The vehicle 1000 may further include a controller 200 and a motor 300 , wherein the controller 200 is used to control the battery 100 to supply power to the motor 300 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1000 .

[0086] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve 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.

[0087] Please refer to Figure 2 , Figure 2 This is a schematic structural diagram of a battery 100 provided in some embodiments of the present application. The battery 100 includes a housing 10 and a battery cell 20 . The housing 10 is used to accommodate the battery cell 20 .

[0088] Among them, the box body 10 is a component for accommodating the battery cell 20, and the box body 10 provides a storage space for the battery cell 20. The box body 10 can adopt a variety of structures. In some embodiments, the box body 10 may include a first part 11 and a second part 12, and the first part 11 and the second part 12 cover each other to define a storage space for accommodating the battery cell 20. The first part 11 and the second part 12 may be in a variety of shapes, such as a cuboid, a cylinder, etc. The first part 11 may be a hollow structure with one side open, and the second part 12 may also be a hollow structure with one side open, and the open side of the second part 12 covers the open side of the first part 11, so as to form a box body 10 with a storage space. It is also possible that the first part 11 is a hollow structure with one side open, and the second part 12 is a plate-like structure, and the second part 12 covers the open side of the first part 11, so as to form a box body 10 with a storage space. The first part 11 and the second part 12 may be sealed by a sealing element, and the sealing element may be a sealing ring, a sealant, etc.

[0089] In the battery 100, there may be one or more battery cells 20. If there are more than one battery cell 20, the battery cells 20 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the battery cells 20 are connected in series and in parallel. A battery module may be formed by connecting a plurality of battery cells 20 in series, in parallel, or in a mixed connection, and then the plurality of battery modules are connected in series, in parallel, or in a mixed connection to form a whole and accommodated in the box 10. Alternatively, all the battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by all the battery cells 20 is accommodated in the box 10.

[0090] Please refer to Figure 3 , Figure 3 An exploded view of a battery cell 20 provided in some embodiments of the present application, the battery cell 20 includes a housing 21 , an electrode assembly 22 , and an end cap assembly 23 .

[0091] The housing 21 is a component for accommodating the electrode assembly 22. The housing 21 may be a hollow structure with an opening formed at one end. The housing 21 may be in various shapes, such as a cylinder, a cuboid, etc. The housing 21 may be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0092] The electrode assembly 22 in the housing 21 may be one or more. Figure 3 As shown, there are multiple electrode assemblies 22, and the multiple electrode assemblies 22 are stacked.

[0093] The electrode assembly 22 is a component in the battery cell 20 where an electrochemical reaction occurs. The electrode assembly 22 may include a positive electrode sheet, a negative electrode sheet, and a separator. The electrode assembly 22 may be a wound structure formed by winding the positive electrode sheet, the separator, and the negative electrode sheet, or a stacked structure formed by stacking the positive electrode sheet, the separator, and the negative electrode sheet.

[0094] The positive electrode plate may include a positive electrode current collector and a positive electrode active material layer coated on opposite sides of the positive electrode current collector. The negative electrode plate may include a negative electrode current collector and a negative electrode active material layer coated on opposite sides of the negative electrode current collector. The electrode assembly 22 has a positive electrode tab 221 and a negative electrode tab 222. The positive electrode tab 221 may be a portion of the positive electrode plate that is not coated with the positive electrode active material layer, and the negative electrode tab 222 may be a portion of the negative electrode plate that is not coated with the negative electrode active material layer.

[0095] The end cap assembly 23 is a component that covers the opening of the shell 21 to isolate the internal environment of the battery cell 20 from the external environment. The end cap assembly 23 covers the opening of the shell 21, and the end cap assembly 23 and the shell 21 together define a sealed space for accommodating the electrode assembly 22, the electrolyte and other components. The shape of the end cap assembly 23 can be adapted to the shape of the shell 21. For example, if the shell 21 is a rectangular parallelepiped structure, the end cap assembly 23 is a rectangular plate structure that is adapted to the shell 21. For another example, if the shell 21 is a cylindrical structure, the end cap assembly is a circular plate structure that is adapted to the shell 21.

[0096] Please refer to Figures 4 to 6 , Figure 4 is a structural schematic diagram of an end cover assembly 23 provided in one embodiment of the present application, Figure 5 yes Figure 4 The cross-sectional view along the AA direction is shown in Figure 2. Figure 6 yes Figure 5 A partial enlarged view of point B in the middle.

[0097] An embodiment of the present application further provides an end cap assembly 23, which can be used for a battery cell 20, and the end cap assembly 23 includes a cover plate 231, a vent assembly 232, and an identification portion 233. The cover plate 231 is provided with a receiving hole 2311 extending along a first direction X, the vent assembly 232 is placed in the receiving hole 2311 and connected to the cover plate 231, and the vent assembly 232 is used to discharge gas inside the battery cell 20. The identification portion 233 is arranged on the vent assembly 232 and is located on a side of the vent assembly 232 in the first direction X away from the electrode assembly 22.

[0098] The shape of the cover plate 231 can match the shape of the housing 21, and the cover plate 231 is used to close the opening of the housing 21 and is connected to the housing 21. The material of the cover plate 231 can also be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of the cover plate 231 and the material of the housing 21 can be the same or different.

[0099] The cover plate 231 may be provided with an electrode terminal, which is used to be electrically connected to the electrode assembly 22 to output the electrical energy of the battery cell 20. The electrode terminal may include a positive electrode terminal 235 and a negative electrode terminal 236. The positive electrode terminal 235 is used to be electrically connected to the positive electrode tab 221, and the negative electrode terminal 236 is used to be electrically connected to the negative electrode tab 222. The positive electrode terminal 235 may be directly connected to the positive electrode tab 221 or indirectly connected, and the negative electrode terminal 236 may be directly connected to the negative electrode tab 222 or indirectly connected.

[0100] The first direction X can be understood as the thickness direction of the cover plate 231. The shape of the receiving hole 2311 can be set according to requirements. In the first direction X, the orthographic projection of the receiving hole 2311 can be circular, elliptical or polygonal. When it is a polygon, it can be a regular polygon.

[0101] The vent assembly 232 is used to discharge the gas generated in the battery cell 20. The vent assembly 232 can cover the receiving hole 2311 and be connected to the cover plate 231. The vent assembly 232 and the cover plate 231 can be connected by welding or other methods.

[0102] The identification portion 233 includes but is not limited to a barcode, a QR code, text, etc., and can be used to indicate the battery cell 20 code corresponding to the end cap assembly 23 .

[0103] The logo portion 233 can be disposed on the breathable component 232 by etching or the like, and of course, can also be formed on the breathable component 232 by printing or the like.

[0104] The end cap assembly 23 provided in one embodiment of the present application and the setting of the vent assembly 232 can be used to discharge the gas inside the battery cell 20, reducing the probability of thermal runaway of the battery cell 20. Since the identification part 233 is set in the vent assembly 232 and is located on the side of the vent assembly 232 away from the electrode assembly 22 in the first direction X, it can provide space for the setting of the identification part 233 and at the same time be away from the injection area of ​​the end cap assembly 23, so as to avoid the electrolyte inside the battery cell 20 from corroding the identification part 233 during the injection and spraying of liquid, resulting in the problem of unclear identification part 233, which is conducive to the identification of the battery cell 20 where the end cap assembly 23 is located, and meets the tracking of relevant parameters of the battery cell 20 during the manufacturing and use process.

[0105] In some optional embodiments, in an end cap assembly 23 provided by an embodiment of the present application, the positive projection of the identification portion 233 in the first direction X is a first pattern, and the first pattern includes at least one of a barcode, a QR code, and text.

[0106] The first pattern may include only one of a barcode, a QR code and text.

[0107] Of course, the first pattern may also include two of the barcode, the QR code and text. For example, the first pattern may include both the barcode and the QR code, or both the barcode and text, or both the QR code and text.

[0108] In some examples, the first pattern may also include a barcode, a QR code, and text at the same time.

[0109] An end cap assembly 23 provided in an embodiment of the present application makes the positive projection of the identification portion 233 in the first direction X into a first pattern, and the first pattern includes at least one of a barcode, a QR code and text, which is beneficial to the setting of the identification portion 233 on the breathable assembly 232, and at the same time can avoid the setting of the identification portion 233 affecting the strength and breathability of the breathable assembly 232.

[0110] In some optional embodiments, in an end cap assembly 23 provided by an embodiment of the present application, the identification portion 233 includes at least one of a printed pattern and an etched pattern disposed on the breathable assembly 232 .

[0111] The identification portion 233 may include a printed pattern disposed on the breathable component 232 , or may include an etched pattern disposed on the breathable component 232 , and of course, may also include both a printed pattern and an etched pattern disposed on the breathable component 232 .

[0112] An end cap assembly 23 provided in one embodiment of the present application enables the identification portion 233 to include at least one of a printed pattern and an etched pattern arranged on the breathable component 232, so that the identification portion 233 can be formed on the breathable component 232 by using a printing or etching process. The operation is simple and will not affect the breathability and strength of the breathable component 232.

[0113] See also Figures 4 to 7 , Figure 7 It is a partial exploded view of the end cover assembly 23 according to one embodiment of the present application.

[0114] In some optional embodiments, the breathable component 232 includes a fixing part 2321 and a breathable film layer 2322 , the breathable film layer 2322 is used to discharge the gas inside the battery cell 20 , the fixing part 2321 is used to connect the cover plate 231 to fix the breathable film layer 2322 , and the identification portion 233 is arranged on the fixing part 2321 .

[0115] The fixing member 2321 may be a component mounted on the cover plate 231. For example, the fixing member 2321 may include a plate-like structure mounted on the cover plate 231. When the plate-like structure is provided, a vent hole may be provided on the top of the plate-like structure. Of course, the fixing member 2321 may also be an annular structure to ensure the circulation of gas.

[0116] The breathable film layer 2322 has a breathable function, and its material can be PP (polypropylen), PE (polyethylene), PU (polyurethane), etc. The gas inside the battery cell 20 needs to pass through the breathable film layer 2322 when it is discharged. The breathable film layer 2322 can allow the gas inside the battery cell 20 to flow to the outside, and can prevent water vapor outside the battery cell 20 from entering the inside of the battery cell 20.

[0117] The breathable membrane layer 2322 can be connected to the fixing member 2321 by bonding or chemical bonding.

[0118] The end cap assembly 23 provided in one embodiment of the present application can ensure the gas discharge requirements of the end cap assembly 23 when used in the battery cell 20 by making the vent assembly 232 adopt the above-mentioned structural form, thereby avoiding thermal runaway of the battery cell 20. At the same time, the fixing member 2321 can provide a setting space for the identification part 233, reduce the risk of the identification part 233 being corroded by the electrolyte, and meet the tracking of relevant parameters of the battery cell 20 during the manufacturing and use process.

[0119] See also Figures 8 to 11 FIG. 2 is a schematic diagram of the structure of an end cover assembly 23 provided in another embodiment of the present application. Fig. 9is a structural schematic diagram of an end cover assembly 23 provided in another embodiment of the present application. Fig.10 yes Fig. 9 The cross-sectional view along the CC direction is shown in Figure 2. Fig.11 yes Fig.10 A partial enlarged view of point D in the middle.

[0120] In some optional embodiments, the end cap assembly 23 and the breathable assembly 232 provided in one embodiment of the present application may further include a protective film layer 2323 , wherein the protective film layer 2323 is connected to the cover plate 231 and covers the fixing member 2321 .

[0121] When the breathable component 232 includes a protective film layer 2323, the identification portion 233 is not limited to being set on the fixing member 2321, and the identification portion 233 can be set on at least one of the fixing member 2321 and the protective film layer 2323. That is to say, when the breathable component 232 includes both the fixing member 2321 and the protective film layer 2323, the identification portion 233 can be set on the fixing member 2321, and of course, the identification portion 233 can also be set on the protective film layer 2323. Of course, the identification portion 233 can also be set on both the fixing member 2321 and the protective film layer 2323. When the identification portion 233 is set on both, one can be made redundant for the other to avoid damage to the identification portion 233 on one of them, which makes the battery cell 20 where the end cap assembly 23 is located untraceable. The protective film layer 2323 can be a waterproof film layer, etc.

[0122] An end cap assembly 23 provided in an embodiment of the present application can protect the fixing part 2321 by setting a protective film layer 2323, thereby reducing the probability of scratches, wear, moisture corrosion and the like of the specified parts. In addition, the setting of the protective film layer 2323 can also provide more options for the position and setting method of the identification part 233, which is conducive to the implementation of the scheme of setting the identification part 233 in the breathable assembly 232.

[0123] See also Figures 4 to 11 As shown in some optional embodiments, in the end cover assembly 23 provided in each embodiment of the present application, the fixing member 2321 is a plate-like structure covering the accommodating hole 2311, the fixing member 2321 is provided with air holes 2321a, the air-permeable membrane layer 2322 covers the air holes 2321a in the first direction X, and the identification portion 233 is at least partially arranged on the side of the fixing member 2321 in the first direction X away from the air-permeable membrane layer 2322.

[0124] The structural shape of the fixing member 2321 can match the shape of the accommodating hole 2311. The fixing member 2321 can be located in the accommodating hole 2311. The fixing member 2321 can be flush with the upper surface of the cover plate 231 in the first direction X. Of course, the fixing member 2321 can also be spaced apart from the upper surface of the cover plate 231.

[0125] The number of the air holes 2321a provided on the fixing member 2321 may be one, or more than two. When there are more than two, the two or more air holes 2321a may be spaced apart from each other. The two or more air holes 2321a may be arranged in rows and columns or arrays, or may be arranged in sequence along a circular track, or may be arranged in sequence along a straight track or a curved track. When the number of the air holes 2321a is more than two, the air permeable membrane layer 2322 covers each of the air holes 2321a in the first direction X.

[0126] The shape of the air hole 2321a can be circular, oval, or oval.

[0127] The end cap assembly 23 provided in one embodiment of the present application can ensure the installation and support of the breathable membrane layer 2322 by the fixing member 2321 through the above arrangement, thereby ensuring the breathability requirement. In addition, the fixing member 2321 in the form of a plate-like structure is conducive to the arrangement of the identification part 233. Improving the recognizability of the identification part 233 is conducive to tracking the relevant parameters of the battery cell 20 where the end cap assembly 23 is located during the manufacturing and use process.

[0128] In some optional embodiments, in an end cap assembly 23 provided by an embodiment of the present application, the identification portion 233 includes an etching pattern disposed on a surface of a side of the fixing member 2321 that is away from the breathable membrane layer 2322 in the first direction X.

[0129] The etching pattern may be set on the identification portion 233 by etching methods such as ultrasonic waves and lasers, and the orthographic projection of the etching pattern in the first direction X may be the first pattern mentioned above.

[0130] An end cap assembly 23 provided in an embodiment of the present application facilitates the formation of the identification portion 233 on the fixing member 2321 by making the identification portion 233 include an etched pattern arranged on the surface of one side of the fixing member 2321 away from the breathable membrane layer 2322 in the first direction X, and can ensure the durability of the pattern of the identification portion 233 on the fixing member 2321, which is beneficial to the tracking of relevant parameters of the battery cell 20 during the manufacturing and use processes.

[0131] In some optional embodiments, when the end cap assembly 23 provided in one embodiment of the present application includes a protective film layer 2323 , the protective film layer 2323 can be used to protect the identification portion of the fixing member 2321 .

[0132] Of course, the logo portion 233 may also include a printed pattern disposed on the protective film layer 2323 .

[0133] The orthographic projection of the printed pattern in the first direction X may be the first pattern mentioned above.

[0134] An end cap assembly 23 provided in an embodiment of the present application enables the identification portion 233 to include a printed pattern arranged on the protective film layer 2323, which is beneficial to the formation of the identification portion 233 on the protective film layer 2323 and can ensure the durability of the pattern of the identification portion 233 on the protective film layer 2323, thereby facilitating the tracking of relevant parameters of the battery cell 20 during the manufacturing and use processes.

[0135] like Figures 8 to 11 As shown, in some embodiments, an annular gasket 234 is provided on the cover plate 231, and along the first direction X, the orthographic projection of the gasket 234 is arranged around the orthographic projection of the fixing member 2321, and the protective film layer 2323 is supported on the side of the gasket 234 away from the cover plate 231 and a gap is formed between the gasket 234 and the cover plate 231, and the gasket 234 is disconnected and provided with a notch along its own annular extension direction.

[0136] The end cover assembly 23 provided in an embodiment of the present application can ensure that the protective film layer 2323 covers the fixing member 2321 through the above-mentioned configuration, thereby ensuring the protection of the fixing member 2321. At the same time, the configuration of the pad 234 can support the protective film layer 2323 at a certain height in the first direction X, so that the gas flowing through the breathable film layer 2322 can be smoothly discharged from the gap and the notch, thereby ensuring the exhaust effect.

[0137] See also Figures 4 to 11 As shown, in some optional embodiments, an end cap assembly 23 provided by an embodiment of the present application has a plurality of air holes 2321a which are spaced apart on the fixing member 2321, a support portion 2321b is formed between two adjacent air holes 2321a, the support portion 2321b is spaced apart from the identification portion 233, and the air permeable membrane layer 2322 is at least partially stacked with the support portion 2321b along the first direction X.

[0138] The hole walls of two adjacent vent holes 2321a are at least partially spaced apart, and the support portion 2321b is the area of ​​the fixing member 2321 between the two adjacent vent holes 2321a. In the radial direction Y of the accommodating hole 2311, a support portion 2321b may be formed between each two adjacent vent holes 2321a.

[0139] The support portion 2321b is attached to the breathable membrane layer 2322, and the breathable membrane layer 2322 can contact and abut the support portion 2321b. The breathable membrane layer 2322 and the support portion 2321b can be connected to each other by bonding or chemical bonding.

[0140] The support portion 2321 b and the identification portion 233 are spaced apart from each other, which can be understood as follows: in the first direction X, the orthographic projection of the support portion 2321 b and the orthographic projection of the identification portion 233 are staggered and do not overlap each other.

[0141] The end cap assembly 23 provided in one embodiment of the present application can ensure the exhaust demand by making the number of air holes 2321a more than two. At the same time, the size of each air hole 2321a can be made moderate, so as to avoid the air hole 2321a having a diameter that is too large and affects the strength of the fixing member 2321, and to avoid the air hole 2321a having a diameter that is too small and affects the ventilation efficiency. In addition, the support portion 2321b can be attached to the breathable membrane layer 2322. When the gas inside the battery cell 20 acts on the breathable membrane layer 2322 during the process of being discharged to the outside of the battery cell 20 through the breathable membrane layer 2322, the support portion 2321b can provide the breathable membrane layer 2322 with a force opposite to the internal pressure of the battery cell 20, thereby reducing the deformation of the breathable membrane layer 2322, improving the overall internal pressure resistance of the breathable assembly 232, and thus improving the safety of the battery cell 20. At the same time, the support portion 2321b and the identification portion 233 are spaced apart so that the identification portion 233 can be set in a complete area of ​​the fixing member 2321, ensuring the integrity and continuity of the first pattern formed by its orthographic projection in the first direction X, thereby facilitating the identification of the identification portion 233.

[0142] See also Figures 4 to 11 As shown, in some optional embodiments, the diameter N of the air vent 2321a ranges from 0.5 mm to 3 mm.

[0143] The diameter of the air hole 2321a may be any value between 0.5 mm and 3 mm, including the two end values ​​of 0.5 mm and 3 mm. It may be 1 mm to 2 mm, and may be 1.3 mm, 1.5 mm, 1.8 mm, etc.

[0144] An end cover assembly 23 provided in an embodiment of the present application can ensure the exhaust demand of the air hole 2321a by making the diameter of the air hole 2321a range from 0.5mm to 3mm, which is conducive to setting the number of the air holes 2321a to more than two, and can also avoid the diameter of the air hole 2321a being too large to affect the strength of the fixing part 2321, and can also avoid the diameter of the air hole 2321a being too small to affect the ventilation efficiency.

[0145] See also Figures 4 to 11 As shown, the number of the air holes 2321a can be multiple. Along the radial direction Y of the accommodating hole 2311, there are multiple minimum vertical distances between the outer edge of the air permeable membrane layer 2322 and the hole walls of the multiple air holes 2321a. The minimum value of the multiple minimum vertical distances is D, and the value range of D is 1mm-6mm.

[0146] Of course, see Fig.12As shown, in some optional embodiments, the number of the air hole 2321a is one, and along the radial direction Y of the accommodating hole 2311, the minimum vertical distance between the outer edge of the air permeable membrane layer 2322 and the hole wall of the air permeable hole 2321a is D, and the value range of D is 1mm-6mm.

[0147] When the number of air holes 2321a is one, the minimum vertical distance D between the outer edge of the air permeable membrane layer 2322 and the hole wall of the air hole 2321a can be any value between 1mm and 6mm, including 1mm, 6mm, and can be optionally 2mm to 5mm. For example, 2mm, 3mm, 4mm, and 5mm can be used.

[0148] When there are multiple air holes 2321a, the multiple air holes 2321a may be arranged close to the outer edge of the air-permeable film layer 2322 or relatively farther from the outer edge of the air-permeable film layer 2322 in the radial direction Y of the accommodating hole 2311. The distance between the air hole 2321a located outside and closest to the edge of the air-permeable film layer 2322 and the air-permeable edge relative to other air holes 2321a in the radial direction Y may be any value between 1 mm and 6 mm, including 1 mm and 6 mm, and may be 2 mm to 5 mm, and illustratively, 2 mm, 3 mm, 4 mm, and 5 mm may be used.

[0149] The end cap assembly 23 provided in an embodiment of the present application can, through the above-mentioned arrangement, make the distance between the hole wall of the air hole 2321a and the edge of the air permeable film layer 2322 moderate regardless of whether one or more air permeable film layers 2322 are used, thereby reducing the probability of affecting the bonding strength between the air permeable film layer 2322 and the fixing part 2321 due to too small a distance, and at the same time reducing the probability of affecting the ventilation effect due to reducing the number of air permeable holes 2321a due to too large a distance.

[0150] See also Figures 4 to 11 As shown, in some embodiments, along the radial direction Y of the accommodating hole 2311, a first vertical distance between the outer edge of the breathable membrane layer 2322 and the outer edge of the fixing member 2321 is d, and the value range of d is 1 mm-5 mm.

[0151] The value range of d can be any value between 1mm-5mm, including the two end values ​​of 1mm and 5mm, and can be selected as any value between 1.5mm-4mm. For example, 2mm, 3mm, etc. can be used.

[0152] By setting the value range of d to 1mm-5mm, the value of d can be made moderate and avoid being too small. When the fixing part 2321 is connected to the cover plate 231 by welding or the like, the residual heat of laser welding will melt the breathable membrane. At the same time, it can also avoid being too large, reducing the number of air holes 2321a and affecting the ventilation effect.

[0153] In some embodiments, along the first direction X, the accommodating hole 2311 includes a first hole segment 2311a, a second hole segment 2311b and a third hole segment 2311c, the radial dimension of the first hole segment 2311a is greater than the radial dimension of the second hole segment 2311b, a first step surface 2311d is connected between the first hole segment 2311a and the second hole segment 2311b, the radial dimension of the second hole segment 2311b is greater than the radial dimension of the third hole segment 2311c, the fixing member 2321 is supported on the first step surface 2311d, and the breathable membrane layer 2322 is located in the second hole segment 2311b.

[0154] The entire accommodating hole 2311 may be a stepped through hole. The first hole segment 2311a, the second hole segment 2311b, and the third hole segment 2311c may be coaxially arranged. Of course, the first hole segment 2311a and the second hole segment 2311b may be coaxially arranged. The third hole segment 2311c may be coaxially arranged with the first hole segment 2311a and the second hole segment 2311b, or may not be coaxially arranged. The third hole segment 2311c may be used to guide the gas inside the battery cell 20 to the second hole segment 2311b.

[0155] An end cap assembly 23 provided by an embodiment of the present application has a receiving hole 2311 adopting the above-mentioned structural form, so that the air hole 2321a can accommodate the air permeable assembly 232 and ensure the installation and support of the air permeable assembly 232, thereby ensuring the air permeability effect and improving the safety performance of the battery to which the end cap assembly 23 is applied.

[0156] In some embodiments, the hardness of the fixing member 2321 is less than that of the cover plate 231 , and the fixing member 2321 and the cover plate 231 are both made of aluminum alloy.

[0157] The hardness mentioned can be understood as the Brinell hardness. The fixing member 2321 can be made of first-series aluminum, and the cover plate 231 can be made of third-series aluminum.

[0158] Through the above arrangement, when the identification part 233 is arranged on the fixing part 2321, since the fixing part 2321 is made of a material with relatively low hardness, the processing and manufacturing properties of the identification part 233 can be improved, and the clarity of the identification part 233 can be improved. At the same time, the brightness of the fixing part 2321 can be reduced, so that the reflection effect of the identification part 233 can be reduced when it is identified.

[0159] In some optional embodiments, the aluminum alloy of the fixing member 2321 includes the following components in mass percentage: aluminum ≥ 99.6%, copper ≤ 0.05%, iron ≤ 0.35%, magnesium ≤ 0.03%, manganese ≤ 0.03%, silicon ≤ 0.25%, titanium ≤ 0.03%, vanadium ≤ 0.05%, zinc ≤ 0.05%, and other single elements ≤ 0.03%; the aluminum alloy of the cover plate 231 includes the following components in mass percentage: aluminum ≥ 96.7%, 0.05% ≤ copper ≤ 0.2%, iron ≤ 0.7%, manganese ≤ 1.5%, silicon ≤ 0.6%, zinc ≤ 0.1%, other single element components ≤ 0.05%, and the total composition of other elements ≤ 0.15%.

[0160] Through the above configuration, it is possible to ensure that the hardness of the fixing member 2321 is less than the hardness of the cover plate 231 , and it is also convenient for the identification portion 233 to be formed on the fixing member 2321 .

[0161] like Figures 8 to 11As shown, the end cap assembly 23 provided in the embodiment of the present application includes a cover plate 231, a vent assembly 232 and an identification portion 233. The cover plate 231 is provided with a receiving hole 2311 extending along the first direction X, the receiving hole 2311 includes a first hole segment 2311a, a second hole segment 2311b and a third hole segment 2311c, the radial dimension of the first hole segment 2311a is greater than the radial dimension of the second hole segment 2311b, a first step surface 2311d is connected between the first hole segment 2311a and the second hole segment 2311b, the radial Y dimension of the second hole segment 2311b is greater than the radial Y dimension of the third hole segment 2311c, the vent assembly 232 is placed in the receiving hole 2311 and connected to the cover plate 231, and the vent assembly 232 is used to discharge the gas inside the battery cell 20. The breathable component 232 includes a fixing part 2321, a breathable film layer 2322 and a protective film layer 2323; the fixing part is supported on the first step surface 2311d and is welded to the cover plate 231, the breathable film layer is located in the second hole section, the fixing part 2321 is provided with a breathable hole 2321a, the breathable film layer 2322 covers the breathable hole 2321a in the first direction X, the protective film layer 2323 is connected to the cover plate 231 and covers the fixing part 2321, the number of the breathable holes 2321a is multiple and is spaced apart on the fixing part 2321, a supporting portion 2321b is formed between two adjacent breathable holes 2321a, the supporting portion 2321b is spaced apart from the identification portion 233, the breathable film layer 2322 is at least partially stacked with the supporting portion 2321b along the first direction X, and the diameter of the breathable hole 2321a ranges from 0.5mm to 3mm. There are multiple air holes 2321a. Along the radial direction Y of the accommodating hole 2311, there are multiple minimum vertical distances between the outer edge of the air permeable membrane layer 2322 and the hole wall of the multiple air permeable holes 2321a. The minimum value of the multiple minimum vertical distances is D, and the value range of D is 1mm-6mm. Along the radial direction Y of the accommodating hole 2311, the first vertical distance between the outer edge of the air permeable membrane layer 2322 and the outer edge of the fixing member 2321 is d, and the value range of d is 1mm-5mm. An annular pad 234 is arranged on the cover plate 231. Along the first direction X, the orthographic projection of the pad 234 is arranged around the orthographic projection of the fixing member 2321. The protective film layer 2323 is supported on the side of the pad 234 away from the cover plate 231 and a gap is formed between the pad 234 and the cover plate 231. The pad 234 is disconnected and provided with a gap along its own annular extension direction. The identification part 233 is arranged on the fixing member 2321. The identification part 233 includes an etched pattern disposed on the fixing member 2321 , and the orthographic projection of the identification part 233 in the first direction X is a first pattern, and the first pattern includes a two-dimensional code. The fixing member 2321 is a plate-shaped structure disposed to cover the receiving hole 2311 .

[0162] According to some embodiments of the present application, the present application further provides a battery cell 20, comprising a housing 21, an electrode assembly 22, and an end cap assembly 23 of any of the above schemes, wherein the housing 21 has an inner cavity and an opening communicating with the inner cavity. The electrode assembly 22 is disposed in the inner cavity, and the end cap assembly 23 is disposed to close the opening and is connected to the housing 21.

[0163] According to some embodiments of the present application, the present application further provides a battery, comprising the battery cell 20 described in any of the above schemes.

[0164] According to some embodiments of the present application, the present application further provides an electrical device, comprising the battery described in any of the above schemes, and the battery is used to provide electrical energy to the electrical device.

[0165] The power-consuming device may be any of the aforementioned devices or systems using batteries.

[0166] 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 replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. An end cap assembly for a battery cell, wherein the battery cell comprises an electrode assembly, characterized in that: The end cap assembly comprises: A cover plate, wherein the cover plate is provided with a receiving hole extending along a first direction; A vent assembly, disposed in the receiving hole and connected to the cover plate, the vent assembly being used to discharge gas inside the battery cell; The identification portion is arranged on the breathable component and is located on a side of the breathable component away from the electrode component in the first direction.

2. The end cap assembly according to claim 1, characterized in that: The orthographic projection of the identification portion in the first direction is a first pattern, and the first pattern includes at least one of a barcode, a two-dimensional code, and text.

3. The end cap assembly according to claim 1 or 2, characterized in that: The identification portion includes at least one of a printed pattern and an etched pattern disposed on the breathable component.

4. The end cap assembly according to any one of claims 1 to 3, characterized in that: The breathable component includes a fixing member, a breathable film layer and a protective film layer; Along the first direction, the breathable film layer is used to discharge the gas inside the battery cell, the fixing piece is used to connect the cover plate to fix the breathable film layer, the protective film layer is connected to the cover plate and covers the fixing piece, and the identification portion is arranged on at least one of the fixing piece and the protective film layer.

5. The end cap assembly according to any one of claims 1 to 3, characterized in that: The breathable component includes a fixing part and a breathable film layer, the breathable film layer is used to discharge the gas inside the battery cell, the fixing part is used to connect the cover plate to fix the breathable film layer, and the identification part is arranged on the fixing part.

6. The end cap assembly according to claim 4 or 5, characterized in that: The fixing member is a plate-like structure covering the accommodating hole, the fixing member is provided with a ventilation hole, the ventilation film layer covers the ventilation hole in the first direction, and the identification part is at least partially arranged on a side of the fixing member away from the ventilation film layer in the first direction.

7. The end cap assembly according to claim 6, characterized in that: The identification portion includes an etching pattern arranged on a surface of the fixing element on one side away from the breathable membrane layer in the first direction.

8. The end cap assembly according to claim 6 or 7, characterized in that: There are multiple ventilation holes and they are spaced apart on the fixing member. A support portion is formed between two adjacent ventilation holes. The support portion is spaced apart from the identification portion. The breathable membrane layer is at least partially stacked with the support portion along the first direction.

9. The end cap assembly according to any one of claims 6 to 8, characterized in that: The diameter N of the air vents ranges from 0.5 mm to 3 mm.

10. The end cap assembly according to any one of claims 6 to 9, characterized in that: The number of the air-permeable hole is one, and along the radial direction of the accommodating hole, the minimum vertical distance between the outer edge of the air-permeable membrane layer and the hole wall of the air-permeable hole is D, and the value range of D is 1 mm-6 mm; Alternatively, there are multiple air holes, and along the radial direction of the accommodating hole, there are multiple minimum vertical distances between the outer edge of the air permeable membrane layer and the hole walls of the multiple air holes, the minimum value of the multiple minimum vertical distances is D, and the value range of D is 1mm-6mm.

11. The end cap assembly according to claim 4, characterized in that: The identification portion includes a printed pattern disposed on the protective film.

12. The end cap assembly according to claim 4 or 11, characterized in that: An annular gasket is arranged on the cover plate, and along the first direction, the orthographic projection of the gasket is arranged around the orthographic projection of the fixing member, the protective film layer is supported on the side of the gasket away from the cover plate and a gap is formed between the gasket and the cover plate, and the gasket is disconnected and provided with a notch along its own annular extension direction.

13. The end cap assembly according to any one of claims 4 to 12, characterized in that: The hardness of the fixing member is less than that of the cover plate, and the fixing member and the cover plate are both made of aluminum alloy.

14. The end cap assembly according to claim 13, characterized in that: The aluminum alloy of the fixing part includes the following components in percentage by mass: aluminum ≥ 99.6%, copper ≤ 0.05%, iron ≤ 0.35%, magnesium ≤ 0.03%, manganese ≤ 0.03%, silicon ≤ 0.25%, titanium ≤ 0.03%, vanadium ≤ 0.05%, zinc ≤ 0.05%, and other single elements ≤ 0.03%; The aluminum alloy of the cover plate includes the following components in percentage by mass: aluminum ≥ 96.7%, 0.05% ≤ copper ≤ 0.2%, iron ≤ 0.7%, manganese ≤ 1.5%, silicon ≤ 0.6%, zinc ≤ 0.1%, other single element components ≤ 0.05%, and other elements in total ≤ 0.15%.

15. The end cap assembly according to any one of claims 4 to 14, characterized in that: Along the radial direction of the accommodating hole, a first vertical distance between the outer edge of the breathable membrane layer and the outer edge of the fixing member is d, and the value range of d is 1 mm-5 mm.

16. The end cap assembly according to any one of claims 4 to 15, characterized in that: Along the first direction, the accommodating hole includes a first hole segment, a second hole segment and a third hole segment, the radial dimension of the first hole segment is larger than the radial dimension of the second hole segment, a first step surface is connected between the first hole segment and the second hole segment, the radial dimension of the second hole segment is larger than the radial dimension of the third hole segment, the fixing part is supported on the first step surface, and the breathable membrane layer is located in the second hole segment.

17. A battery cell, characterized in that: include: A shell having an inner cavity and an opening communicating with the inner cavity; An electrode assembly, disposed in the inner cavity; The end cover assembly according to any one of claims 1 to 16, wherein the end cover assembly is arranged to close the opening and is connected to the shell.

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

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

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