End cap assembly, battery cell, battery and electrical device

Abstract

The present application relates to an end cap assembly, a battery cell, a battery and an electrical device. The end cap assembly includes an end cap, which is provided with an injection hole; a first sealing structure, which is sealed at one end of the injection hole away from the interior of the battery cell; and a second sealing structure, which is arranged on the end cap, and the second sealing structure is constructed to be able to block the injection hole, and is located outside the injection hole on the side of the first sealing structure facing the injection hole, and a first fluid channel connected to the injection hole is formed between the second sealing structure and the end cap. Since the first sealing section of the second sealing structure is arranged outside the injection hole, it has no sealing effect on the injection hole, and the injection hole is only sealed under the action of the first sealing structure, so that during the sealing detection process, the inert gas inside the battery cell can enter the injection hole through the first fluid channel, and then the sealing performance of the first sealing structure can be detected to ensure that the first sealing structure is sealed reliably.

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] During the production process of battery cells, electrolyte injection is often required, and after the injection is completed, it needs to be sealed with a sealing plastic nail, and then the sealing aluminum nail is welded to the top cover. Among them, being able to effectively detect the sealing of the sealing aluminum nail is particularly important for ensuring the sealing of the battery cell.

[0003] In some detection methods, an inert gas for detection, such as helium, can be injected into the battery first, and then the sealing plastic nails and welding sealing aluminum nails are installed in sequence, and then the battery cell is placed in a vacuum environment to perform inert gas leakage detection. However, there is a problem that the detection results are not reliable. Summary of the invention

[0004] In view of the above problems, the present application provides an end cover assembly, a battery cell, a battery and an electrical device, which can alleviate the problem of unreliable test results in the existing method of testing the sealing performance of sealed aluminum nails.

[0005] In a first aspect, the present application provides an end cap assembly for a battery cell, comprising:

[0006] The end cover is provided with a liquid injection hole;

[0007] A first sealing structure, sealing at an end of the liquid injection hole away from the interior of the battery cell; and

[0008] The second sealing structure is arranged on the end cover, and is constructed to be able to block the injection hole. The second sealing structure is located outside the injection hole on the side of the first sealing structure facing the injection hole, and a first fluid channel connected to the injection hole is formed between the second sealing structure and the end cover.

[0009] In the above-mentioned end cover assembly, since the second sealing structure is arranged outside the injection hole, it has no sealing effect on the injection hole, and the injection hole is sealed only under the action of the first sealing structure. Therefore, during the sealing detection process, the inert gas inside the battery cell can enter the injection hole through the first fluid channel, and then the sealing performance of the first sealing structure can be detected to ensure that the first sealing structure is sealed reliably.

[0010] In addition, since the second sealing structure can serve as a part of the end cover assembly and does not fall into the interior of the battery cell housing, it will not affect the normal operation of the battery cell assembly and the like.

[0011] In some embodiments, the first sealing structure has a sealing surface sealed at an end of the liquid injection hole away from the interior of the battery cell;

[0012] In the axial direction of the injection hole, the distance between the end of the second sealing structure facing the first sealing structure and the sealing surface is a, and the depth of the injection hole between the sealing surface and the second sealing structure is b, a≥b.

[0013] By setting a≥b, the second sealing structure can be completely separated from the injection hole and no longer have a sealing effect on the injection hole, so that the inert gas can successfully enter the injection hole to detect the first sealing structure.

[0014] In some embodiments, the end cover assembly further includes an isolation structure, which is disposed between the first sealing structure and the second sealing structure in the axial direction of the injection hole, and has a size of c, c≥b, in the axial direction of the injection hole.

[0015] By providing an isolation structure between the first sealing structure and the second sealing structure, the first sealing structure and the second sealing structure can be effectively separated to prevent the second sealing structure from returning to the injection hole during the battery cell manufacturing process.

[0016] In some embodiments, a first gap is provided between the isolation structure and the inner wall of the injection hole to form a second fluid channel communicating with the first fluid channel.

[0017] The existence of a first gap between the isolation structure and the inner wall of the injection hole means that, in the radial direction of the injection hole, there is a first gap between the isolation structure and the inner wall of the injection hole.

[0018] In some embodiments, the radial dimension of the isolation structure gradually increases toward the second sealing structure.

[0019] By setting the radial dimension of the isolation structure to gradually increase toward the second sealing structure, the thrust acting on the isolation structure can be stably applied to the second sealing structure, thereby enabling the second sealing structure to stably move toward the direction away from the injection hole.

[0020] In some embodiments, the isolation structure is fixed to a side of the first sealing structure facing the second sealing structure.

[0021] By providing an isolation structure fixedly connected to the first sealing structure, it is possible to prevent other external components from interfering with the second sealing structure, causing the second sealing structure to detach from the injection hole in advance, thereby causing sealing failure and electrolyte leakage and pollution.

[0022] In some embodiments, the isolation structure is fixed to a side of the second sealing structure facing the first sealing structure.

[0023] By setting up an isolation structure connected to the second sealing structure, since the second sealing structure is sealed to the injection hole, the isolation structure can also be stably installed on the end cover, and then during the movement of the first sealing structure toward the injection hole, the isolation structure can stably push the second sealing structure to move in the direction away from the injection hole.

[0024] In some embodiments, the isolation structure abuts against the first sealing structure in the injection hole.

[0025] In this way, it can be prevented that the second sealing structure returns to the liquid injection hole under other forces after the first sealing structure is sealed, thereby affecting the leakage detection of the first sealing structure.

[0026] In some embodiments, the isolation structure includes a supporting section and a connecting section, one end of the connecting section is connected to the supporting section, and the other end is connected to the second sealing structure, and a first gap is provided between the connecting section and the inner wall of the injection hole to form a second fluid channel connected to the first fluid channel;

[0027] The support section is supported in the injection hole, and a first fluid space is formed between the support section and the first sealing structure;

[0028] The supporting section is provided with a fourth fluid channel which connects the first fluid space with the second fluid channel.

[0029] By arranging the support section to support the liquid injection hole, it is possible to prevent the second sealing structure from completely separating from the liquid injection hole and falling into the interior of the battery cell, thereby affecting the performance of the battery cell.

[0030] In some embodiments, in the axial direction of the injection hole, a second gap is provided between the support segment and the first sealing structure to form a first fluid space.

[0031] By being arranged in the axial direction of the injection hole, a second gap is provided between the support section and the first sealing structure, which can expand the space of the first fluid space, so that the fluid can fully enter the first fluid space and then reach the sealing point between the first sealing structure and the injection hole, thereby improving the detection reliability.

[0032] In some embodiments, the injection hole includes a first hole and a second hole, the aperture of the first hole is larger than the aperture of the second hole, the first hole is axially connected to the second hole to form a stepped hole, and the support section is supported at the step of the stepped hole.

[0033] The step support is simple, so that the structure of the injection hole is also simple, and the support for the second sealing structure is also reliable.

[0034] In some embodiments, the end cover has a receiving cavity communicated with the injection hole, and the second sealing structure is accommodated in the receiving cavity.

[0035] By providing a receiving cavity to receive the second sealing structure, the second sealing structure can be reliably received, thereby preventing it from falling into the interior of the battery cell and affecting the performance of the battery cell.

[0036] In some embodiments, a third gap is provided between the cavity wall of the receiving cavity and the second sealing structure to form a first fluid channel.

[0037] By providing a third gap between the cavity wall of the receiving cavity and the second sealing structure to form the first fluid channel, the formation method of the first fluid channel is simple.

[0038] In some embodiments, the end cap includes an end cap body and a lower plastic part arranged on one side of the end cap body, the end cap body is provided with a liquid injection hole, the lower plastic part has a receiving cavity or a receiving cavity is defined between the lower plastic part and the end cap body.

[0039] The receiving cavity is arranged on the lower plastic part, thus making full use of the position below the injection hole and simplifying the overall structure.

[0040] In some embodiments, a side of the lower plastic part facing the end cover body is partially recessed to form a receiving cavity.

[0041] The receiving cavity is formed by the depression, so that the second sealing structure can conveniently enter the receiving cavity from the opening end formed by the depression, and the receiving process is also stable and reliable.

[0042] In a second aspect, the present application provides a battery cell, comprising the end cover assembly in any of the above embodiments.

[0043] In the above-mentioned battery cell, since the second sealing structure is arranged outside the injection hole, it has no sealing effect on the injection hole, and the injection hole is only sealed under the action of the first sealing structure. Therefore, during the sealing detection process, the inert gas inside the battery cell can enter the injection hole through the first fluid channel, and then the sealing performance of the first sealing structure can be detected, ensuring that the sealing of the first sealing structure is reliable.

[0044] In addition, since the second sealing structure can serve as a part of the end cover assembly and does not fall into the interior of the battery cell housing, it will not affect the normal operation of the battery cell assembly and the like.

[0045] In a third aspect, the present application provides a battery, comprising:

[0046] The housing; and

[0047] The battery cell in any of the above embodiments is accommodated in a box.

[0048] In the above-mentioned battery, since the second sealing structure is arranged outside the injection hole, it has no sealing effect on the injection hole, and the injection hole is sealed only under the action of the first sealing structure. Therefore, during the sealing detection process, the inert gas inside the battery cell can enter the injection hole through the first fluid channel, and then the sealing performance of the first sealing structure can be detected, ensuring that the sealing of the first sealing structure is reliable.

[0049] In addition, since the second sealing structure can serve as a part of the end cover assembly and does not fall into the interior of the battery cell housing, it will not affect the normal operation of the battery cell assembly and the like.

[0050] In a fourth aspect, the present application provides an electrical device, comprising a battery according to any of the above embodiments, the battery being used to provide electrical energy; or

[0051] The battery cell comprises a battery cell according to any of the above embodiments, and the battery cell is used to provide electrical energy.

[0052] In the above-mentioned electrical device, since the second sealing structure is arranged outside the injection hole, it has no sealing effect on the injection hole. The injection hole is only sealed under the action of the first sealing structure. Therefore, during the sealing detection process, the inert gas inside the battery cell can enter the injection hole through the first fluid channel, and then the sealing performance of the first sealing structure can be detected, ensuring that the first sealing structure is sealed reliably.

[0053] In addition, since the second sealing structure can serve as a part of the end cover assembly and does not fall into the interior of the battery cell housing, it will not affect the normal operation of the battery cell assembly and the like.

[0054] 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

[0055] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the following detailed description of the preferred embodiments.The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application.

[0056] Moreover, in all the drawings, the same reference numerals are used to represent the same parts. In the drawings:

[0057] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0058] Figure 2 An exploded view of a battery provided for some embodiments of the present application;

[0059] Figure 3 A schematic diagram of the exploded structure of a battery cell according to some embodiments of the present application;

[0060] Figure 4 It is a schematic cross-sectional structure diagram of an end cover assembly of some embodiments of the present application;

[0061] Figure 5 for Figure 4 A schematic cross-sectional view of the second sealing structure of the end cover assembly when sealing the injection hole;

[0062] Figure 6 for Figure 4 A schematic cross-sectional view of the structure when the first sealing structure and the second sealing structure of the end cover assembly do not seal the injection hole;

[0063] Figure 7 Schematic diagram of the cross-sectional structure of the end cover assembly of other embodiments of the present application;

[0064] Figure 8 for Figure 7 A schematic cross-sectional view of the second sealing structure of the end cover assembly when sealing the injection hole;

[0065] Fig. 9 for Figure 7 A schematic cross-sectional view of the structure when the first sealing structure and the second sealing structure of the end cover assembly do not seal the injection hole;

[0066] Fig.10 Schematic diagram of the cross-sectional structure of the end cover assembly of some other embodiments of the present application;

[0067] Fig.11 for Fig.10 A schematic cross-sectional view of the second sealing structure of the end cover assembly when sealing the injection hole;

[0068] Fig.12 for Fig.10 The cross-sectional structure schematic diagram of the end cover assembly shown is when the first sealing structure and the second sealing structure of the end cover assembly do not seal the injection hole.

[0069] The reference numerals in the specific implementation manner are as follows:

[0070] Vehicles 1000;

[0071] Battery 100;

[0072] Controller 200;

[0073] Motor 300;

[0074] Box 10;

[0075] Part I 11, Part II 12;

[0076] Battery cell 20;

[0077] End cover 21, pole 211, injection hole 212, main hole 2121, sealing hole 2122, first hole 2123, second hole 2124, receiving cavity 213, end cover body 214, lower plastic part 215;

[0078] Housing 22;

[0079] Battery cell assembly 23, pole ear 231;

[0080] End cap assembly 24;

[0081] The first sealing structure 241 , the second sealing section 2412 , the first extension section 2413 , the second sealing structure 242 , the first fluid channel 243 , the isolation structure 244 , the support section 2441 , the connecting section 2442 , the second fluid channel 245 , the first fluid space 246 , the third fluid channel 247 , and the guide structure 248 .

[0082] The first gap m1;

[0083] The second gap m2;

[0084] The third gap m3. DETAILED DESCRIPTION

[0085] 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.

[0086] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0087] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0088] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0089] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0090] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0091] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments 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 the embodiments of the present application.

[0092] In the description of the embodiments 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, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0093] Compared with other types of batteries, lithium batteries have the characteristics of light weight and high energy density, and are being used in many fields such as small household appliances, IT equipment, power tools, electric vehicles, etc. Lithium battery cells can be roughly divided into four components: positive electrode, negative electrode, electrolyte, and separator, none of which can be missing.

[0094] Among them, the electrolyte of the lithium battery cell is the "blood" of the lithium battery and the carrier of ion transmission. It plays the role of conducting lithium ions between the positive and negative electrodes, providing an environment for lithium ions to be freely embedded and de-embedded, and is one of the key components of the lithium battery cell.

[0095] During the manufacturing process of the battery cell, the electrolyte needs to be injected into the battery housing through the injection hole opened on the end cover, and after the injection, it needs to be sealed by a sealing structure to prevent the electrolyte from leaking from the injection hole.

[0096] The sealing structure of the prior art sealing injection hole mainly includes two parts:

[0097] 1) Use a sealing plastic nail (or sealing nail, rubber plug, etc.) to block the through hole of the injection hole to prevent electrolyte leakage;

[0098] 2) The sealing aluminum nail (or sealing aluminum cover, sealing nail, etc.) is welded and sealed with the end cover by laser welding.

[0099] In order to test the sealing reliability of the sealing structure, an inert gas, such as helium, will be injected into the battery cell before the sealing plastic nail is used for sealing. Then the sealing plastic nail and the sealing aluminum nail will be installed in sequence. After these processes are completed, the finished battery cell will be placed in a vacuum environment for inert gas leakage detection.

[0100] Assuming that the airtightness of other parts of the battery cell is good, and the sealing function of the sealing plastic nail is intact while the welding airtightness of the sealing aluminum nail is poor, the leakage of inert gas cannot be detected during the leakage detection, and the battery cell with poor welding airtightness of the sealing aluminum nail cannot be ruled out. In addition, during long-term use, the sealing plastic nail may lose its airtightness due to vibration, aging, etc. At this time, the sealing aluminum nail with poor welding airtightness cannot play a sealing role, and the battery cell leaks. In short, the detection result will be unreliable.

[0101] In order to alleviate the problem of unreliable leakage detection results of inert gas caused by existing sealing structures, the applicant has discovered through research that an end cover assembly has been designed, including an end cover, a first sealing structure and a second sealing structure. The end cover is provided with an injection hole. The first sealing structure is sealed at one end of the injection hole away from the interior of the battery cell. The second sealing structure is arranged on the end cover. The second sealing structure is constructed to be able to block the injection hole and is located outside the injection hole on the side of the first sealing structure facing the injection hole, and a first fluid channel connected to the injection hole is formed between the end cover and the second sealing structure.

[0102] In such an end cap assembly, since the second sealing structure has no sealing effect on the injection hole, the injection hole is sealed only under the action of the first sealing structure. Therefore, during the sealing detection process, the inert gas inside the battery cell can enter the injection hole through the first fluid channel, and then the sealing performance of the first sealing structure can be detected to ensure that the first sealing structure is sealed reliably.

[0103] In addition, since the second sealing structure can serve as a part of the end cover assembly and does not fall into the shell of the battery cell, it will not affect the normal operation of the electrode assembly and the like.

[0104] The end cover assembly disclosed in the embodiment of the present application is applied to a battery cell. The battery cell disclosed in the embodiment of the present application can be used in, but not limited to, electrical devices such as vehicles, ships or aircraft.

[0105] The embodiment of the present application provides an electric device using a battery as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0106] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0107] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 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, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided 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. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0108] 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.

[0109] Please refer to Figure 2 , Figure 2An exploded view of a battery 100 provided in some embodiments of the present application. The battery 100 includes a box 10 and a battery cell 20, and the battery cell 20 is contained in the box 10. Among them, the box 10 is used to provide a storage space for the battery cell 20, and the box 10 can adopt a variety of structures. In some embodiments, the box 10 may include a first part 11 and a second part 12, the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define a storage space for accommodating the battery cell 20. The second part 12 may be a hollow structure with one end open, the first part 11 may be a plate-like structure, and the first part 11 covers the open side of the second part 12, so that the first part 11 and the second part 12 jointly define a storage space; the first part 11 and the second part 12 may also be hollow structures with one side open, and the open side of the first part 11 covers the open side of the second part 12. Of course, the box 10 formed by the first part 11 and the second part 12 may be in a variety of shapes, such as a cylinder, a cuboid, etc.

[0110] 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 mixed connection. A mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the box 10; of course, the battery 100 may also be a battery module formed by connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 10. The battery 100 may also include other structures, for example, the battery 100 may also include a busbar component for realizing electrical connection between the multiple battery cells 20.

[0111] Each battery cell 20 may be a secondary battery or a primary battery, or 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.

[0112] Please refer to Figure 3 , Figure 3 The schematic diagram of the exploded structure of the battery cell 20 provided in some embodiments of the present application. The battery cell 20 refers to the smallest unit that constitutes the battery. Figure 3 The battery cell 20 includes an end cover 21, a shell 22, a battery cell assembly 23 and other functional components.

[0113] The end cap 21 refers to a component that covers the opening of the shell 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 can be adapted to the shape of the shell 22 to match the shell 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 21 is not easily deformed when squeezed and 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 poles 211 can be provided on the end cap 21. The pole 211 can be used to electrically connect with the battery cell assembly 23 for outputting or inputting electrical energy of the battery cell 20. In some embodiments, the end cap 21 can also be provided with a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The material of the end cap 21 can also be a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose special restrictions on this. In some embodiments, an insulating structure may be provided inside the end cap 21, and the insulating structure may be used to isolate the electrical connection components in the housing 22 from the end cap 21 to reduce the risk of short circuit. For example, the insulating structure may be plastic, rubber, or the like.

[0114] The shell 22 is a component used to cooperate with the end cover 21 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the battery cell assembly 23, electrolyte and other components. The shell 22 and the end cover 21 can be independent components, and an opening can be set on the shell 22, and the internal environment of the battery cell 20 is formed by covering the opening with the end cover 21 at the opening. Without limitation, the end cover 21 and the shell 22 can also be integrated. Specifically, the end cover 21 and the shell 22 can form a common connection surface before other components are put into the shell, and when the interior of the shell 22 needs to be encapsulated, the end cover 21 covers the shell 22. The shell 22 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the shell 22 can be determined according to the specific shape and size of the battery cell assembly 23. The material of the shell 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0115] The battery cell assembly 23 is a component in the battery cell 20 where electrochemical reactions occur. One or more battery cell assemblies 23 may be contained in the housing 22. The battery cell assembly 23 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active substances constitute the main body of the battery cell assembly, and the parts of the positive and negative electrode sheets without active substances each constitute a tab 231. The positive tab and the negative tab may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery, the positive active substance and the negative active substance react with the electrolyte, and the tab 231 connects the electrode terminals to form a current loop.

[0116] According to some embodiments of the present application, referring to Figure 4 , Figure 4 It is a schematic diagram of the cross-sectional structure of the end cover assembly according to some embodiments of the present application. The present application provides an end cover assembly 24. The end cover assembly 24 includes an end cover 21, a first sealing structure 241 and a second sealing structure 242. The end cover 21 is provided with an injection hole 212. The first sealing structure 241 is sealed at one end of the injection hole 212 away from the battery cell 20. The second sealing structure 242 is provided on the end cover 21. The second sealing structure 242 is configured to be able to block the injection hole 212, and is located outside the injection hole 212 on the side of the first sealing structure 241 facing the injection hole 212, and a first fluid channel 243 connected to the injection hole 212 is formed between the end cover 21.

[0117] The first sealing structure 241 and the second sealing structure 242 refer to structures capable of sealing the injection hole 212. In the embodiment of the present application, the first sealing structure 241 can be a sealing aluminum nail, which can be sealed at the first opening at one end of the injection hole and sealed by welding with the end cover 21.

[0118] The second sealing structure 242 may be a sealing plastic nail, and the first sealing section 2421 elastically abuts against the inner wall of the injection hole 212 to achieve sealing.

[0119] Of course, in other embodiments, the first sealing structure 241 and the second sealing structure 242 may also be other sealing methods, which are not limited here.

[0120] The first sealing structure 241 is sealed at the end of the injection hole 212 away from the interior of the battery cell 20, which means that the injection hole 212 includes a main hole 2121 and a sealing hole 2122 connected in the axial direction, and the sealing hole 2122 is provided at the end of the main hole 2121 away from the interior of the battery cell 20, and the first sealing structure 241 is sealed at the sealing hole 2122. The first sealing section 2421 of the second sealing structure 242 is configured to block the main hole 2121.

[0121] In such an end cover 21, since the second sealing structure 242 is arranged outside the injection hole 212, it has no sealing effect on the injection hole 212. The injection hole 212 is only sealed under the action of the first sealing structure 241. Therefore, during the sealing detection process, the inert gas inside the battery cell 20 can enter the injection hole 212 through the first fluid channel 243, and then the sealing performance of the first sealing structure 241 can be detected to ensure that the first sealing structure 241 is sealed reliably.

[0122] In addition, since the second sealing structure 242 can serve as a part of the end cover assembly 24 and does not fall into the shell 22 of the battery cell 20, it will not affect the normal operation of the battery cell assembly 23 and the like.

[0123] It should be pointed out that the first fluid channel 243 should be fluidly connected to the first sealing structure 241 through the injection hole 212. In this way, the fluid entering the first fluid channel 243 can be partially or fully connected with a surface of the first sealing structure 241 facing the injection hole 212 through the injection hole 212, thereby detecting the sealing reliability of the first sealing structure 241.

[0124] Optionally, the shape of the second sealing structure 242 is configured to be able to block the injection hole 212. Specifically, the cross-sectional shape of the second sealing structure 242 matches the cross-sectional shape of the injection hole 212 along its radial direction. Specifically, when the injection hole 212 is a cylindrical hole, the second sealing structure 242 can be cylindrical, or spherical, etc., which is not limited here. By setting the shape of the second sealing structure 242 to be configured to be able to block the injection hole 212, the way the second sealing structure 242 is relative to the injection hole 212 can be simple, and the second sealing structure 242 can be easily separated from the injection hole 212.

[0125] According to some embodiments of the present application, referring to Figures 4 to 6 The first sealing structure 241 has a sealing surface 2411 that seals the end of the injection hole 212 away from the inside of the battery cell 20. In the axial direction of the injection hole 212, the distance between the end of the second sealing structure 242 facing the first sealing structure 241 and the sealing surface 2411 is a, and the depth of the injection hole 212 between the sealing surface 2411 and the second sealing structure 242 is b, a ≥ b.

[0126] The axial direction of the injection hole 212 refers to the direction of the axis line AA of the injection hole 212 .

[0127] Specifically, the depth of the injection hole 212 between the sealing surface 2411 and the second sealing structure 242 is the depth of the main hole 2121 .

[0128] By setting a≥b, the second sealing structure 242 can be completely separated from the injection hole 212 and no longer has a sealing effect on the injection hole 212, so that the inert gas can successfully enter the injection hole 212 to detect the first sealing structure 241.

[0129] According to some embodiments of the present application, referring to Figures 4 to 6 The end cover assembly 24 further includes an isolation structure 244. In the axial direction of the injection hole 212, the isolation structure 244 is disposed between the first sealing structure 241 and the second sealing structure 242. In the axial direction of the injection hole 212, the size of the isolation structure 244 is c, c≥b.

[0130] By providing the isolation structure 244 between the first sealing structure 241 and the second sealing structure 242 , the first sealing structure 241 and the second sealing structure 242 can be effectively separated to prevent the second sealing structure 242 from returning to the injection hole 212 during the manufacturing process of the battery cell 20 .

[0131] Furthermore, before the second sealing structure 242 is separated from the injection hole 212, during the process of the first sealing structure 241 sealing the injection hole 212, the force acting on the first sealing structure 241 can be transmitted to the second sealing structure 242 through the isolation structure 244, thereby enabling the second sealing structure 242 to reliably separate from the injection hole 212 when the first sealing structure 241 is sealed to the injection hole 212. This not only simplifies the separation process of the second sealing structure 242, but also reduces the time from the second sealing structure 242 separating from the injection hole 212 to the first sealing structure 241 sealing the injection hole 212, thereby preventing a large amount of inert gas from escaping from the injection hole 212 to the outside during this period, thereby affecting the detection effect.

[0132] Optionally, the extension direction of the isolation structure 244 may be the axial direction of the injection hole 212 , or may be a direction inclined to the axial direction of the injection hole 212 , or may be a bent shape.

[0133] According to some embodiments of the present application, referring to Figures 4 to 6 A first gap m1 is defined between the isolation structure 244 and the inner wall of the injection hole 212 to form a second fluid channel 245 communicating with the first fluid channel 243 .

[0134] The first gap m1 is provided between the isolation structure 244 and the inner wall of the injection hole 212 , which means that the first gap m1 is provided between the isolation structure 244 and the inner wall of the injection hole 212 in the radial direction of the injection hole 212 .

[0135] By providing a first gap m1 between the isolation structure 244 and the inner wall of the liquid injection hole 212 , the communication between the liquid injection hole 212 and the second fluid channel 245 can be made simple and reliable.

[0136] Optionally, a first gap m1 is provided between the isolation structure 244 and the inner wall of the injection hole 212, and the first gap m1 is arranged around the isolation structure 244. In this way, the airflow entering the injection hole 212 from the first fluid channel 243 can reach the sealing part of the first sealing structure 241 sealing the injection hole 212 in all directions, so as to improve the reliability of leakage detection.

[0137] In other embodiments, the isolation structure 244 may also be provided with an airflow channel, and both ends of the airflow channel are respectively connected to the first fluid channel 243 and the injection hole 212. More specifically, the shape of the isolation structure 244 is configured to match the shape of the injection hole 212.

[0138] According to some embodiments of the present application, referring to Figure 7 to Figure 9 The radial dimension of the isolation structure 244 gradually increases toward the direction approaching the second sealing structure 242 .

[0139] The radial dimension of the isolation structure 244 refers to the radial dimension of the isolation structure 244 along the injection hole 212 .

[0140] By setting the radial dimension of the isolation structure 244 to gradually increase in the direction approaching the second sealing structure 242, the thrust acting on the isolation structure 244 can be stably applied to the second sealing structure 242, thereby enabling the second sealing structure 242 to stably move in the direction away from the injection hole 212.

[0141] Specifically, the isolation structure 244 is cone-shaped.

[0142] The cone referred to in the present application does not necessarily have a triangular axial cross-sectional shape, but may also be a trapezoidal shape, which is not limited here.

[0143] By setting the isolation structure 244 to be conical, the structure can be simplified while improving its structural strength.

[0144] In other embodiments, the isolation structure 244 may be shaped as follows: Figures 4 to 6 The cylindrical shape shown can also be a rectangular parallelepiped shape or other special shapes, which are not limited here.

[0145] According to some embodiments of the present application, referring to Figures 4 to 6 The isolation structure 244 is fixed to a side of the first sealing structure 241 facing the second sealing structure 242 .

[0146] By providing the isolation structure 244 fixedly connected to the first sealing structure 241, it is possible to prevent other external components from interfering with the second sealing structure 242, causing the second sealing structure 242 to detach from the injection hole 212 in advance, thereby causing sealing failure and electrolyte leakage and pollution.

[0147] Optionally, when the second sealing structure 242 seals the injection hole 212, one end of the second sealing structure 242 facing the first sealing structure 241 sealing the injection hole 212 is disposed in the injection hole 212. In this way, it is possible to prevent the second sealing structure 242 from being exposed outside the injection hole 212 before the first sealing structure 241 is sealed in the injection hole 212, and from being separated from the injection hole 212 in advance due to impact by external components.

[0148] Optionally, the isolation structure 244 is configured to be integrally formed with the first sealing structure 241 .

[0149] Integral molding refers to the use of an integral molding process to integrally manufacture and mold the entire component including the isolation structure 244 and the first sealing structure 241 .

[0150] By arranging the isolation structure 244 to be integrally formed with the first sealing structure 241 , the manufacturing process can be simplified and the connection between the isolation structure 244 and the first sealing structure 241 can be made tighter.

[0151] According to some embodiments of the present application, referring to Figure 7 to Figure 9 The isolation structure 244 is fixed to a side of the second sealing structure 242 facing the first sealing structure 241 .

[0152] By setting up an isolation structure 244 connected to the second sealing structure 242, since the second sealing structure 242 is sealed to the injection hole 212, the isolation structure 244 can also be stably installed on the end cover 21, and then when the first sealing structure 241 moves toward the injection hole 212, the isolation structure 244 can stably push the second sealing structure 242 to move in the direction of leaving the injection hole 212.

[0153] When the second sealing structure 242 seals the injection hole 212, the end of the isolation structure 244 facing away from the second sealing structure 242 extends out of the injection hole 212. When the first sealing structure 241 moves toward the injection hole 111, it can push the isolation structure 244 to cause the second sealing structure 242 to separate from the injection hole 212.

[0154] By setting one end of the isolation structure 244 facing away from the second sealing structure 242, the isolation structure 244 extends out from the injection hole 212 when the second sealing structure 242 seals the injection hole 212, so that the second sealing structure 242 can be pushed outside the injection hole 111 when the first sealing structure 241 moves toward the injection hole 111, thereby making the second sealing structure 242 detach from the injection hole 212. Since the stroke of the first sealing structure 241 pushing the second sealing structure 242 includes at least the axial dimension of the isolation structure 244 protruding outside the injection hole 111, it is ensured that the second sealing structure 242 can successfully detach from the injection hole 212.

[0155] In other embodiments, one end of the isolation structure 244 facing away from the second sealing structure 242 is disposed in the injection hole 212. In this way, the second sealing structure 242 can be ensured to be successfully separated from the injection hole 212 by increasing the stroke of the first sealing structure 241 in the injection hole 212. However, due to the limited thickness of the end cover 21, if the stroke of the first sealing structure 241 in the injection hole 212 is increased, the axial dimension of the matching portion between the injection hole 212 and the second sealing structure 242 will be reduced, affecting the sealing effect of the second sealing structure 242. In addition, it is not convenient to weld the first sealing structure 241 and the end cover 21.

[0156] Optionally, the isolation structure 244 is configured to be integrally formed with the second sealing structure 242 .

[0157] By arranging the isolation structure 244 to be integrally formed with the second sealing structure 242 , the manufacturing process can be simplified and the connection between the isolation structure 244 and the second sealing structure 242 can be made tighter.

[0158] In other embodiments, the isolation structure 244 may also be a structure independent of the first sealing structure 241 and the second sealing structure 242. Specifically, the isolation structure 244 may be separated from the first sealing structure 241 and the second sealing structure 242, or may be offset against at least one of them.

[0159] According to some embodiments of the present application, referring to Figure 7 to Figure 9 The isolation structure 244 and the first sealing structure 241 are in contact with each other in the injection hole 212 .

[0160] In this way, it is possible to prevent the second sealing structure 242 from returning to the injection hole 212 under other forces after being sealed by the first sealing structure 241 , thereby affecting the leakage detection of the first sealing structure 241 .

[0161] In other embodiments, the isolation structure 244 and the first sealing structure 241 may not abut against each other in the injection hole 212. The second sealing structure 242 can be kept under its own gravity so that the first sealing section 2421 does not return to the injection hole 212.

[0162] According to some embodiments of the present application, referring to Figure 10 to Figure 12, the isolation structure 244 includes a support section 2441 and a connection section 2442. One end of the connection section 2442 is connected to the support section 2441, and the other end is connected to the second sealing structure 242. There is a first gap m1 between the connection section 2442 and the inner wall of the injection hole 212 to form a second fluid channel 245 connected to the first fluid channel 243. Among them, the support section 2441 is supported in the injection hole 212 and forms a first fluid space 246 with the first sealing structure 241. The support section 2441 is provided with a third fluid channel 247 connecting the first fluid space 246 and the second fluid channel 245.

[0163] Specifically, the fluid from the first fluid channel 243 will pass through the second fluid channel 245, the third fluid channel 247 and the first fluid space 246 in sequence, and then reach the sealing position of the first sealing structure 241 sealing the injection hole 212, thereby realizing leakage detection.

[0164] By providing the support section 2441 to support the liquid injection hole 212 , it is possible to prevent the second sealing structure 242 from completely separating from the liquid injection hole 212 and falling into the battery cell 20 , thereby affecting the performance of the battery cell 20 .

[0165] Optionally, in the axial direction of the injection hole 212 , the support section 2441 is provided with a first communication hole, and the first communication hole forms a third fluid channel 247 .

[0166] According to some embodiments of the present application, referring to Figure 10 to Figure 12 In the axial direction of the injection hole 212 , a second gap m2 is provided between the support section 2441 and the first sealing structure 241 to form a first fluid space 246 .

[0167] It can be understood that the support section 2441 should be matched with the gap of the injection hole 212. In this way, after the first sealing structure 241 pushes the isolation structure 244 to allow the support section 2441 to enter the injection hole 212, it can continue to move downward under the action of its own gravity of the second sealing structure 242, thereby being supported in the injection hole 212 and forming a second gap m2 between the first sealing structure 241.

[0168] By being arranged in the axial direction of the injection hole 212, a second gap m2 is provided between the support section 2441 and the first sealing structure 241, which can expand the space of the first fluid space 246, so that the fluid can fully enter the first fluid space 246 and then reach the sealing point between the first sealing structure 241 and the injection hole 212, thereby improving the detection reliability.

[0169] According to some embodiments of the present application, referring to Figure 10 to Figure 12The injection hole 212 includes a first hole 2123 and a second hole 2124. The aperture of the first hole 2123 is larger than the aperture of the second hole 2124. The first hole 2123 and the second hole 2124 are connected along the circumferential direction to form a stepped hole. The support section 2441 is supported at the step of the stepped hole.

[0170] The step support is simple, so that the structure of the injection hole 212 is also simple, and the support for the second sealing structure 242 is also reliable.

[0171] Specifically, the inner wall of the injection hole 212 includes the first inner wall of the first hole 2123, the second inner wall of the second hole 2124, and the third inner wall, the third inner wall connects the first inner wall and the second inner wall, and the support section 2441 is supported on the third inner wall. More specifically, the angle between the third inner wall and the second inner wall is not greater than 90 degrees.

[0172] Specifically, the main hole 2121 includes a first hole 2123 and a second hole 2124 .

[0173] According to some embodiments of the present application, referring to Figures 4 to 9 The end cap assembly 24 further includes a guide structure 248, which is connected to a side of the second sealing structure 242 away from the first sealing structure 241. In a radial direction parallel to the injection hole 212, the size of the guide structure 248 gradually decreases in a direction away from the second sealing structure 242.

[0174] Specifically, the guide structure 248 may be tapered.

[0175] By providing the guide structure 248 , the second sealing structure 242 can be guided to separate from the injection hole 212 , and the structural strength of the second sealing structure 242 can also be enhanced.

[0176] According to some embodiments of the present application, referring to Figures 4 to 9 The end cover 21 has a receiving cavity 213 connected to the injection hole 212 , and the second sealing structure 242 is accommodated in the receiving cavity 213 .

[0177] By providing the receiving cavity 213 to receive the second sealing structure 242 , the second sealing structure 242 can be reliably received, thereby preventing it from falling into the interior of the battery cell 20 and affecting the performance of the battery cell 20 .

[0178] In the embodiment of the present application, a third gap m3 is provided between the cavity wall of the receiving cavity 213 and the second sealing structure 242 to form a first fluid channel 243 .

[0179] Among them, the third gap m3 may only include the gap between the cavity wall of the receiving cavity 213 and the second sealing structure 242 in the axial direction of the injection hole 212, or may only include the gap between the cavity wall of the receiving cavity 213 and the second sealing structure 242 in the radial direction of the injection hole 212, or may include the gap between the cavity wall of the receiving cavity 213 and the side of the second sealing structure 242 facing the first sealing structure 241 in the axial direction of the injection hole 212, and the gap between the cavity wall of the receiving cavity 213 and the second sealing structure 242 in the radial direction of the injection hole 212.

[0180] The third gap m3 is provided between the cavity wall of the receiving cavity 213 and the second sealing structure 242 to form the first fluid channel 243 , so that the formation method of the first fluid channel 243 is simple.

[0181] According to some embodiments of the present application, referring to Figures 4 to 9 The end cover 21 includes an end cover body 214 and a lower plastic part 215 arranged on one side of the end cover body 214. The end cover body 214 is provided with a liquid injection hole 212, and the lower plastic part 215 has a receiving cavity 213 or a receiving cavity 213 is defined between the lower plastic part 215 and the end cover body 214.

[0182] The receiving cavity 213 is disposed on the lower plastic part, so that the position below the injection hole 212 is fully utilized and the overall structure is simplified.

[0183] According to some embodiments of the present application, referring to Figures 4 to 9 A portion of the lower plastic part 215 facing one side of the end cover body 214 is recessed to form a receiving cavity 213 .

[0184] The receiving cavity 213 is formed by the recess, so that the second sealing structure 242 can conveniently enter the receiving cavity 213 from the opening end formed by the recess, and the receiving process is also stable.

[0185] It should also be noted that a second connecting hole is provided on the lower plastic part 215, and the second connecting hole connects the outside of the end cover assembly 24 with the receiving cavity 213. Thus, the first fluid channel 243 can be connected with the inside of the housing 22 of the battery cell 20 through the second connecting hole, so that the inert gas for detection can successfully enter the injection hole 212.

[0186] According to some embodiments of the present application, the present application provides a battery cell 20 including the end cover assembly 24 in any of the above embodiments.

[0187] Since the second sealing structure 242 is arranged outside the injection hole 212, it has no sealing effect on the injection hole 212. The injection hole 212 is only sealed under the action of the first sealing structure 241. Therefore, during the sealing detection process, the inert gas inside the battery cell 20 can enter the injection hole 212 through the first fluid channel 243, and then the sealing performance of the first sealing structure 241 can be detected to ensure that the first sealing structure 241 is sealed reliably.

[0188] In addition, since the second sealing structure 242 can serve as a part of the end cover assembly 24 and does not fall into the shell 22 of the battery cell 20, it will not affect the normal operation of the battery cell assembly 23 and the like.

[0189] According to some embodiments of the present application, the present application provides a battery 100 , including a box body 10 and a battery cell 20 in any of the above embodiments. The battery cell 20 is accommodated in the box body 10 .

[0190] Since the second sealing structure 242 is arranged outside the injection hole 212, it has no sealing effect on the injection hole 212. The injection hole 212 is only sealed under the action of the first sealing structure 241. Therefore, during the sealing detection process, the inert gas inside the battery cell 20 can enter the injection hole 212 through the first fluid channel 243, and then the sealing performance of the first sealing structure 241 can be detected to ensure that the first sealing structure 241 is sealed reliably.

[0191] In addition, since the second sealing structure 242 can serve as a part of the end cover assembly 24 and does not fall into the shell 22 of the battery cell 20, it will not affect the normal operation of the battery cell assembly 23 and the like.

[0192] According to some embodiments of the present application, the present application provides an electrical device, including the battery 100 in any of the above embodiments, and the battery 100 is used to provide electrical energy.

[0193] Since the second sealing structure 242 is arranged outside the injection hole 212, it has no sealing effect on the injection hole 212. The injection hole 212 is only sealed under the action of the first sealing structure 241. Therefore, during the sealing detection process, the inert gas inside the battery cell 20 can enter the injection hole 212 through the first fluid channel 243, and then the sealing performance of the first sealing structure 241 can be detected to ensure that the first sealing structure 241 is sealed reliably.

[0194] In addition, since the second sealing structure 242 can serve as a part of the end cover assembly 24 and does not fall into the shell 22 of the battery cell 20, it will not affect the normal operation of the battery cell assembly 23 and the like.

[0195] According to some embodiments of the present application, the present application provides an electrical device, including the battery cell 20 in any of the above embodiments, and the battery cell 20 is used to provide electrical energy.

[0196] Since the second sealing structure 242 is arranged outside the injection hole 212, it has no sealing effect on the injection hole 212. The injection hole 212 is only sealed under the action of the first sealing structure 241. Therefore, during the sealing detection process, the inert gas inside the battery cell 20 can enter the injection hole 212 through the first fluid channel 243, and then the sealing performance of the first sealing structure 241 can be detected to ensure that the first sealing structure 241 is sealed reliably.

[0197] In addition, since the second sealing structure 242 can serve as a part of the end cover assembly 24 and does not fall into the shell 22 of the battery cell 20, it will not affect the normal operation of the battery cell assembly 23 and the like.

[0198] According to some embodiments of the present application, see Figures 4 to 6 The present application provides an end cap assembly 24, comprising an end cap 21, a first sealing structure 241, a second sealing structure 242 and an isolation structure 244. The end cap 21 comprises an end cap body 214 and a lower plastic part 215 disposed on one side of the end cap body 214. The end cap body 214 is provided with a liquid injection hole 212, and the lower plastic part 215 is recessed toward one side of the end cap body 214 to form a receiving cavity 213. The first sealing structure 241 is sealed at one end of the liquid injection hole 212 away from the inside of the battery cell 20. The second sealing structure 242 is disposed on the side of the first sealing structure 241 toward the inside of the liquid injection hole 212. The second sealing structure 242 is configured to block the liquid injection hole 212. The second sealing structure 242 is disposed outside the liquid injection hole 212. In the axial direction of the liquid injection hole 212, the isolation structure 244 is disposed between the first sealing structure 241 and the second sealing structure 242, and is configured to be integrally formed with the first sealing structure 241. The isolation structure 244 is cylindrical. The first sealing structure 241 has a sealing surface 2411 that seals the end of the injection hole 212 away from the inside of the battery cell 20. In the axial direction of the injection hole 212, the depth of the injection hole 212 between the sealing surface 2411 and the second sealing structure 242 is b, and the size of the isolation structure 244 is c, where c>b. A first gap m1 is provided between the isolation structure 244 and the inner wall of the injection hole 212 to form a second fluid channel 245 that is connected to the first fluid channel 243. A third gap m3 is provided between the cavity wall of the receiving cavity 213 and the second sealing structure 242 to form the first fluid channel 243. The third gap m3 includes a gap between the cavity wall of the receiving cavity 213 and the side of the second sealing structure 242 facing the first sealing structure 241 in the axial direction of the injection hole 212, and a gap between the cavity wall of the receiving cavity 213 and the second sealing structure 242 in the radial direction of the injection hole 212.

[0199] According to some embodiments of the present application, see Figure 7 to Figure 9 The present application provides an end cap assembly 24, including an end cap 21, a first sealing structure 241, a second sealing structure 242 and an isolation structure 244. The end cap 21 includes an end cap body 214 and a lower plastic part 215 disposed on one side of the end cap body 214. The end cap body 214 is provided with an injection hole 212, and the lower plastic part 215 is recessed toward one side of the end cap body 214 to form a receiving cavity 213. The first sealing structure 241 is sealed at one end of the injection hole 212 away from the inside of the battery cell 20. The second sealing structure 242 is disposed on the side of the first sealing structure 241 toward the injection hole 212. The second sealing structure 242 is configured to block the injection hole 212. The second sealing structure 242 is disposed outside the injection hole 212. In the axial direction of the injection hole 212, the isolation structure 244 is disposed between the first sealing structure 241 and the second sealing structure 242, and is configured to be integrally formed with the second sealing structure 242. The radial dimension of the isolation structure 244 gradually increases in the direction approaching the second sealing structure 242. The isolation structure 244 is conical. The first sealing structure 241 has a sealing surface 2411 that seals the end of the injection hole 212 away from the inside of the battery cell 20. In the axial direction of the injection hole 212, the depth of the injection hole 212 between the sealing surface 2411 and the second sealing structure 242 is b, and the size of the isolation structure 244 is c, c>b. There is a first gap m1 between the isolation structure 244 and the inner wall of the injection hole 212 to form a second fluid channel 245 connected to the first fluid channel 243. There is a third gap m3 between the cavity wall of the receiving cavity 213 and the second sealing structure 242 to form the first fluid channel 243. The third gap m3 includes an axial gap between the cavity wall of the receiving cavity 213 and the side of the second sealing structure 242 facing the first sealing structure 241 in the injection hole 212 , and a radial gap between the cavity wall of the receiving cavity 213 and the second sealing structure 242 in the injection hole 212 .

[0200] According to some embodiments of the present application, see Figure 10 to Figure 12The present application provides an end cap assembly 24, including an end cap 21, a first sealing structure 241, a second sealing structure 242 and an isolation structure 244. The end cap 21 includes an end cap body 214 and a lower plastic part 215 disposed on one side of the end cap body 214. The end cap body 214 is provided with an injection hole 212, and the lower plastic part 215 is recessed toward one side of the end cap body 214 to form a receiving cavity 213. The first sealing structure 241 is sealed at one end of the injection hole 212 away from the inside of the battery cell 20. The second sealing structure 242 is disposed on the side of the first sealing structure 241 toward the injection hole 212. The second sealing structure 242 is configured to block the injection hole 212. The second sealing structure 242 is disposed outside the injection hole 212. In the axial direction of the injection hole 212, the isolation structure 244 is disposed between the first sealing structure 241 and the second sealing structure 242, and is configured to be integrally formed with the second sealing structure 242. The first sealing structure 241 has a sealing surface 2411 that seals the end of the injection hole 212 away from the inside of the battery cell 20. In the axial direction of the injection hole 212, the depth of the injection hole 212 between the sealing surface 2411 and the second sealing structure 242 is b, and the size of the isolation structure 244 is c, where c>b. The isolation structure 244 includes a supporting section 2441 and a connecting section 2442. One end of the connecting section 2442 is connected to the supporting section 2441, and the other end is connected to the second sealing structure 242. There is a first gap m1 between the connecting section 2442 and the inner wall of the injection hole 212 to form a second fluid channel 245 connected to the first fluid channel 243. The supporting section 2441 is supported in the injection hole 212. In the axial direction of the injection hole 212, there is a second gap m2 between the supporting section 2441 and the first sealing structure 241 to form a first fluid space 246. The support section 2441 is provided with a third fluid channel 247 connecting the first fluid space 246 and the second fluid channel 245. A third gap m3 is provided between the cavity wall of the receiving cavity 213 and the second sealing structure 242 to form the first fluid channel 243. The third gap m3 includes a gap between the cavity wall of the receiving cavity 213 and the side of the second sealing structure 242 facing the first sealing structure 241 in the axial direction of the injection hole 212, and a gap between the cavity wall of the receiving cavity 213 and the second sealing structure 242 in the radial direction of the injection hole 212.

[0201] 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, characterized in that: include: The end cover is provided with a liquid injection hole; A first sealing structure, sealed at an end of the injection hole away from the interior of the battery cell; a second sealing structure, disposed on the end cover, the second sealing structure being configured to block the injection hole, and being located outside the injection hole on a side of the first sealing structure facing the injection hole, and forming a first fluid channel communicating with the injection hole between the second sealing structure and the end cover; as well as An isolation structure, fixed to a side of the second sealing structure facing the first sealing structure; Wherein, the first sealing structure has a sealing surface sealed at one end of the liquid injection hole away from the interior of the battery cell; In the axial direction of the injection hole, the depth of the injection hole between the sealing surface and the second sealing structure is b, the isolation structure is provided between the first sealing structure and the second sealing structure, and the size of the isolation structure is c, c≥b.

2. The end cap assembly according to claim 1, characterized in that: In the axial direction of the injection hole, a distance between an end of the second sealing structure facing the first sealing structure and the sealing surface is a, and a≥b.

3. The end cap assembly according to claim 2, characterized in that: A first gap is defined between the isolation structure and the inner wall of the liquid injection hole to form a second fluid channel communicating with the first fluid channel.

4. The end cap assembly according to claim 3, characterized in that: The radial dimension of the isolation structure gradually increases toward the direction approaching the second sealing structure.

5. The end cap assembly according to claim 2, characterized in that: The isolation structure and the first sealing structure abut against each other in the liquid injection hole.

6. The end cap assembly according to claim 2, characterized in that: The isolation structure includes a supporting section and a connecting section, one end of the connecting section is connected to the supporting section, and the other end is connected to the second sealing structure, and a first gap is formed between the connecting section and the inner wall of the injection hole to form a second fluid channel connected to the first fluid channel; The support section is supported in the injection hole to form a first fluid space with the first sealing structure, and the support section is provided with a fourth fluid channel connecting the first fluid space with the second fluid channel.

7. The end cap assembly according to claim 6, characterized in that: In the axial direction of the injection hole, a second gap is provided between the support section and the first sealing structure to form the first fluid space.

8. The end cap assembly according to claim 6, characterized in that: The injection hole includes a first hole and a second hole, the diameter of the first hole is larger than the diameter of the second hole, the first hole is axially connected to the second hole to form a stepped hole, and the support section is supported at the step of the stepped hole.

9. The end cap assembly according to claim 1, characterized in that: The end cover has a receiving cavity communicated with the injection hole, and the second sealing structure is accommodated in the receiving cavity.

10. The end cap assembly according to claim 9, characterized in that: A third gap is provided between the cavity wall of the receiving cavity and the second sealing structure to form the first fluid channel.

11. The end cap assembly according to claim 9, characterized in that: The end cover comprises an end cover body and a lower plastic part arranged on one side of the end cover body, the end cover body is provided with the injection hole, the lower plastic part has the receiving cavity or the receiving cavity is defined between the lower plastic part and the end cover body.

12. The end cap assembly according to claim 11, characterized in that A side portion of the lower plastic part facing the end cover body is recessed to form the receiving cavity.

13. A battery cell, characterized in that: Comprising an end cover assembly as described in any one of claims 1 to 12.

14. A battery, characterized in that: include: Box; as well as The battery cell according to claim 13, wherein the battery cell is accommodated in the casing.

15. An electrical device, characterized in that: comprising a battery as claimed in claim 14, wherein the battery is used to provide electrical energy; or The battery cell according to claim 13 is used to provide electrical energy.

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