End cap assembly, battery cell, battery, electric device, and liquid injection method

Abstract

The application relates to an end cover assembly, a battery monomer, a battery, a power utilization device and a liquid injection method. The end cover assembly (10) for the battery monomer (600) comprises an end cover (1), a sealing piece (2) and a cover body (3). The end cover (1) is provided with a first hole (11) for injecting electrolyte. The sealing piece (2) is used for sealing the first hole (11). The cover body (3) is used for covering at least part of the sealing piece (2). The cover body (3) is rotatable relative to the end cover (1) to realize detachable connection of the cover body (3) and the end cover (1). One of the sealing piece (2) and the cover body (3) is provided with a second hole (21). The other of the sealing piece (2) and the cover body (3) is provided with a boss (31). The boss (31) is used for being inserted into the second hole (21). The boss (31) and the second hole (21) are relatively rotatable to realize rotatable connection of the sealing piece (2) and the cover body (3).

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to an end cap assembly, a battery cell, a battery, an electrical device, and a liquid injection method. Background Technology

[0002] Lithium-ion batteries have advantages such as high energy density, high power density, many cycles, and long storage time, and are widely used in electric vehicles.

[0003] Extending the battery life of electric vehicles has always been a challenge in the industry. Summary of the Invention

[0004] The purpose of this application is to provide a battery cell with improved performance.

[0005] According to a first aspect of this application, an end cap assembly is provided for a battery cell, comprising: The end cap has a first hole for injecting electrolyte; Seals for sealing the first hole; and A cover body for covering at least part of the seal, and the cover body is rotatable relative to the end cap to achieve a detachable connection between the cover body and the end cap; One of the seal and the cover has a second hole, and the other of the seal and the cover has a boss. The boss is used to insert into the second hole and the boss and the second hole can rotate relative to each other to achieve a rotatable connection between the seal and the cover.

[0006] By setting the seal and cover to be interconnected, the seal and cover can be disassembled or installed as a whole when opening or closing the first hole, simplifying the operation steps, shortening the operation time, and improving the operation efficiency.

[0007] In some embodiments, the boss and the second hole are interference-fitted to achieve the connection between the two.

[0008] The boss and the second hole use an interference fit, which allows for both the connection between the seal and the cover, and also enables relative rotation between them. Achieving a rotatable connection between the seal and the cover through an interference fit eliminates the need for additional components or structures, resulting in lower manufacturing costs.

[0009] In some embodiments, the boss includes a first insertion portion, and a first receiving portion is provided on the wall of the second hole, wherein the first insertion portion is received in the first receiving portion to prevent the seal and the cover from detaching.

[0010] By providing a first insertion part and a first receiving part, the first insertion part is inserted into the first receiving part. Through the cooperation of the first insertion part and the first receiving part, the seal and the cover can be prevented from separating from each other, ensuring a stable connection between the seal and the cover.

[0011] In some embodiments, in a direction perpendicular to the axis of the second hole, the cross-sectional area of ​​the first receiving portion gradually increases in the direction away from the inserted end of the second hole, and the first insert portion cooperates with the first receiving portion to prevent the seal and the cover from detaching.

[0012] The cross-sectional area of ​​the first receiving part gradually increases along the direction away from the inserted end of the second hole, which can increase the difficulty of the first insertion part detaching from the first receiving part, thereby restricting the detachment of the sealing element and the cover.

[0013] In some embodiments, the second hole is a blind hole.

[0014] This structure can effectively prevent impurities from entering the interior of the battery cell through the second hole, and can also effectively prevent the electrolyte inside the battery cell from leaking through the second hole.

[0015] In some embodiments, the seal and the end cap are fixed relative to each other in the circumferential direction of the first hole.

[0016] The seal and the end cap are kept relatively fixed in the circumferential direction, which can prevent the seal from rotating with the end cap when the cap rotates relative to the end cap, reduce wear between the seal and the end cap, and reduce the impact on the sealing effect.

[0017] In some embodiments, the axis of rotation of the cover relative to the seal is collinear with the axis of the first hole.

[0018] If the axis of rotation of the cover relative to the seal is not collinear with the axis of the first hole, the seal will rotate due to eccentricity when the cover rotates relative to the seal, causing friction between the seal and the end cap. Therefore, setting the axis of rotation of the cover relative to the seal to be collinear with the axis of the first hole can effectively ensure that the seal does not rotate with the cover when the cover rotates relative to the end cap, reducing friction between the seal and the end cap.

[0019] In some embodiments, the seal includes a sealing post inserted into the first hole. The seal effectively seals the first hole through the sealing post, preventing electrolyte leakage and the entry of impurities.

[0020] In some embodiments, the sealing post is a non-rotating body, and the shape of the first hole matches the seal.

[0021] Setting the sealing column as a non-rotating body can effectively ensure the relative fixation between the seal and the end cap, preventing relative rotation between the seal and the end cap and thus preventing wear.

[0022] In some embodiments, the sealing post is interference-fitted with the first hole.

[0023] By setting the fit between the sealing post and the first hole to an interference fit, it is also possible to increase the difficulty of the sealing post rotating in the first hole, thereby achieving relative fixation between the seal and the end cap.

[0024] In some embodiments, the boss is interference-fitted with the second hole, and the coefficient of friction between the sealing post and the contact surface of the first hole is greater than the coefficient of friction between the boss and the contact surface of the second hole.

[0025] In some embodiments, the seal further includes a thrust plate connected to the sealing post, the thrust plate being located between the cover and the end cap, and the thrust plate engaging with the end face of the first hole.

[0026] When an interference fit is used between the sealing post and the first hole, and between the boss and the second hole, the coefficient of friction of the contact surface between the sealing post and the first hole is set to be greater than the coefficient of friction of the contact surface between the boss and the second hole. When the external force applied to the cover body is sufficient to make the cover body rotate relative to the seal, the external force is insufficient to make the seal rotate relative to the end cover. Therefore, the relative fixation of the seal and the end cover can be guaranteed, and the wear between the seal and the end cover can be reduced.

[0027] In some embodiments, the boss is a rotating body. This structure facilitates the rotation of the boss within the second hole.

[0028] In some embodiments, the end cap has a second receiving portion arranged circumferentially along the first hole, the second receiving portion being used to receive at least a portion of the cap body to achieve limiting of the cap body, the second receiving portion being located on the side of the end cap away from the interior of the battery cell.

[0029] The second receiving portion can accommodate a part of the cover body to restrict the cover body, limiting its degree of freedom in the height direction and preventing the cover body from detaching from the end cap, thus achieving relative fixation between the cover body and the end cap. At the same time, the cover body can at least partially cover the seal, so after the cover body's degree of freedom in the height direction is restricted by the end cap, the seal is also pressed under the cover body, thus also achieving fixation of the seal.

[0030] In some embodiments, the cover body is rotatable relative to the end cap and includes a limiting portion. When the cover body is rotated to a first position, the limiting portion is located within a second receiving portion to restrict the separation of the cover body from the end cap. When the cover body is rotated to a second position, the limiting portion and the second receiving portion are circumferentially misaligned along the first hole to achieve separation of the cover body from the end cap. By providing the limiting portion and cooperating with the second receiving portion, a detachable connection between the end cap and the cover body can be achieved.

[0031] In some embodiments, the boss and the second hole are configured to be rotatable relative to each other at least during the process of rotating the cover from the first position to the second position.

[0032] In some embodiments, the end cap further includes a guide portion communicating with the second receiving portion, and a limiting portion for entering the second receiving portion via the guide portion, or separating from the end cap via the guide portion.

[0033] By setting a guide section, the limiting section can enter the second receiving section more smoothly or separate smoothly, improving the convenience of operation and thus improving the efficiency of operation.

[0034] In some embodiments, the end cap includes an end cap body and a mounting member, the mounting member being disposed on the surface of the end cap body and surrounding the first hole, and a second receiving portion being disposed on the mounting member or the second receiving portion being formed by the mounting member and the end cap body enclosing each other.

[0035] In some embodiments, the seal includes a sealing post inserted into a first hole, and the end of the sealing post near the interior of the battery cell is provided with a guide slope, the length of the guide slope along the axial direction of the first hole being greater than the length of the mounting component along the axial direction of the first hole.

[0036] Since the end cap has a thin plate structure that is not easy to process into complex structures, the second receiving part can be easily formed by setting up mounting components, which can reduce the processing difficulty of the end cap.

[0037] According to a second aspect of this application, a housing assembly is provided for a battery cell, comprising: The housing is used to connect with the end cap to form the outer shell of the battery cell, and the housing is provided with a first hole for injecting electrolyte; Seals for sealing the first hole; and A cover body for covering at least part of the seal, and the cover body is rotatable relative to the end cap to achieve a detachable connection between the cover body and the end cap; One of the seal and the cover has a second hole, and the other of the seal and the cover has a boss. The boss is used to insert into the second hole and the boss and the second hole can rotate relative to each other to achieve a rotatable connection between the seal and the cover.

[0038] According to a third aspect of this application, a battery cell is provided, comprising: An electrode assembly and a housing for housing the electrode assembly, the housing comprising a shell and the aforementioned end cap assembly, the shell having an opening at one end, the end cap assembly covering the opening at the end of the shell; or, An electrode assembly and a housing for housing the electrode assembly, the housing including an end cap and the aforementioned housing assembly, the end of the housing having an opening, the end cap covering the opening at the end of the housing.

[0039] According to a fourth aspect of this application, a battery is provided, comprising a plurality of the aforementioned battery cells.

[0040] According to a fifth aspect of this application, an electrical device is provided, comprising the aforementioned battery cell, wherein the battery cell is used to provide electrical energy.

[0041] According to a sixth aspect of this application, a method for injecting liquid into a battery cell is provided, comprising: Electrolyte is injected through the first hole in the casing of the battery cell; The seal and cover, still connected, are removed to the first hole, and the first hole is sealed with the seal while the seal and cover remain connected, with the cover covering at least part of the seal; and The cover is rotated relative to the seal to achieve relative fixation between the cover and the outer shell.

[0042] In some embodiments, the liquid injection method for a battery cell further includes: Remove the cover and seals that are still connected from the housing.

[0043] In some embodiments, the seal has a second hole, the cover has a boss that is inserted into the second hole, the second hole is a blind hole, and the electrolyte injection method further includes: Before injecting electrolyte through the first hole on the casing of the battery cell. The bottom wall of the second hole is pierced, allowing the second hole to connect the interior of the battery cell with the external environment, thereby releasing the pressure inside the battery cell; and Remove the cover and seals from the housing.

[0044] In some embodiments, the liquid injection method for a battery cell further includes: The cover is rotated from a first position to a second position, causing the limiting portion of the cover to be circumferentially misaligned with the second receiving portion of the outer casing on the side away from the inside of the battery cell, along the first hole; and The cover is rotated from the second position to the first position, causing the limiting part to enter the second receiving part to prevent the cover and seal from separating from the outer shell.

[0045] In some embodiments, the liquid injection method for a battery cell further includes: The rotating cover moves from the first position to the second position, causing the limiting part and the second receiving part to be misaligned circumferentially along the first hole; and Remove the cover and seals that are still connected from the housing.

[0046] According to a seventh aspect of this application, a liquid injection device is provided for a battery cell, comprising: The electrolyte injection mechanism is used to inject electrolyte into the housing through a first hole provided on the housing; and The disassembly and assembly mechanism is used to remove the seal and cover, which are in a connected state, to the first hole before sealing the first hole with the seal, and to seal the first hole with the seal while the seal and cover are in a connected state, to cover at least part of the seal with the cover, and to drive the cover to rotate relative to the seal after the seal and the first hole are engaged, so as to achieve relative fixation of the cover and the outer shell.

[0047] The end cap assembly of this application embodiment is rotatably connected to the cap body through a sealing element. During secondary liquid injection, the sealing element and the cap body can be sealed together with the first hole or detached from the first hole as a whole to close or open the first hole, thereby realizing secondary liquid injection. At the same time, it simplifies the operation steps of secondary liquid injection, effectively shortens the operation time, and improves the operation efficiency. Attached Figure Description

[0048] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1-A Schematic diagrams of some embodiments of vehicles using the battery cells of this application; Figure 1-B These are schematic diagrams illustrating the structure of some embodiments of the battery in this application; Figure 1-C These are schematic diagrams illustrating the structure of some embodiments of the battery module of this application; Figure 1-D These are exploded views of some embodiments of the battery cells of this application; Figure 2 This is an exploded view of some embodiments of the end cap assembly of this application; Figure 3 This is an assembly diagram of some embodiments of the seal and cover body in the end cap assembly of this application; Figure 4 These are cross-sectional views of some embodiments of the end cap assembly of this application; Figure 5 This is a schematic diagram of the structure of some embodiments of the seal in the first embodiment; Figure 6 These are cross-sectional views of some embodiments of the seal in the first embodiment; Figure 7 These are schematic diagrams of the structure of some embodiments of the cover in the first embodiment; Figure 8 This is a structural schematic diagram of some embodiments of the cover in the first embodiment from another angle; Figure 9 These are cross-sectional views of some embodiments of the cover in the first embodiment; Figure 10 This is a cross-sectional view of the mating structure of the cover and the seal in the second embodiment; Figure 11 These are cross-sectional views of some embodiments of the seal in the second embodiment; Figure 12 This is a cross-sectional view of the mating structure of the cover and the seal in the third embodiment; Figure 13 These are cross-sectional views of some embodiments of the cover in the third embodiment; Figure 14 These are cross-sectional views of some embodiments of the seal in the third embodiment; Figure 15 This is a cross-sectional view of the mating structure of the cover and the seal in the fourth embodiment; Figure 16 These are cross-sectional views of some embodiments of the seal in the fourth embodiment; Figure 17 This is a schematic diagram of the structure of some embodiments of the cover in the fourth embodiment; Figure 18 These are cross-sectional views of some embodiments of the cover in the fourth embodiment; Figure 19A and Figure 19B The images are a schematic diagram and a bottom view of the seal in the fifth embodiment, respectively. Figure 20A and Figure 20B These are front and rear structural schematic diagrams of some embodiments of the mounting components in this application; Figure 21A and Figure 21B These are top views and AA cross-sectional views of some embodiments of the mounting components in this application, respectively; Figure 22 This is a partial structural diagram of end cap 1 in this application; Figure 23 This is a schematic diagram of the mating structure of the end cap, seal, and cover in some embodiments of this application; Figure 24 This is a schematic diagram of the structure of some embodiments of the housing assembly used in this application for a battery cell; Figure 25 This is a schematic flowchart of some embodiments of the battery cell liquid injection method of this application; Figure 26 This is a schematic diagram illustrating the composition of some embodiments of the liquid injection device of this application. Detailed Implementation

[0049] The present application is described in detail below. In the following paragraphs, different aspects of the embodiments are defined in more detail. The aspects so defined may be combined with any other aspect or aspects unless expressly stated otherwise. In particular, any feature considered preferred or advantageous may be combined with one or more other features considered preferred or advantageous.

[0050] The terms "first" and "second" used in this application are merely for ease of description and to distinguish different components with the same name, and do not indicate any sequential or primary / secondary relationship.

[0051] Furthermore, when an element is referred to as being "on" another element, the element may be directly on the other element, or it may be indirectly on the other element with one or more intermediate elements inserted between them. Additionally, when an element is referred to as being "connected" to another element, the element may be directly connected to the other element, or it may be indirectly connected to the other element with one or more intermediate elements inserted between them. In the following drawings, the same reference numerals denote the same elements.

[0052] In this application, "multiple" refers to two or more, and similarly, "multiple groups" refers to two or more groups.

[0053] To clearly describe the various orientations in the following embodiments, for example Figure 1-D The coordinate system in the diagram defines the various directions of the battery: the x-direction represents the length of the battery cell 600; the y-direction, perpendicular to the x-direction in the horizontal plane, represents the width of the battery cell 600; and the z-direction, perpendicular to the plane formed by the x and y directions, represents the height of the battery cell 600. Based on this orientation definition, terms such as "up," "down," "top," "bottom," "front," "back," "inner," and "outer" are used to indicate orientation or positional relationships. This is only for the convenience of describing this application and does not indicate or imply that the device referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the scope of protection of this application.

[0054] There are many problems that affect the lifespan of lithium-ion batteries. Over the years, those skilled in the art have tried to solve this problem from many different angles, but the expected results have not yet been achieved.

[0055] As part of the invention process described in this application, the inventors, through analysis and research, discovered that one of the reasons for battery lifespan issues is that during battery use, repeated charge-discharge cycles inevitably lead to irreversible electrolyte degradation, resulting in a decrease in battery capacity. Therefore, the inventors found that replenishing the electrolyte during battery use can effectively slow down the rate of capacity reduction and extend battery lifespan.

[0056] Lithium-ion batteries mainly consist of four parts: positive electrode material, negative electrode material, electrolyte, and separator. The electrolyte acts as an ion conductor between the positive and negative electrodes and is generally composed of a lithium salt electrolyte and an organic solvent. To prevent electrolyte leakage and contamination of the surrounding air and environment during use, or to prevent water vapor or metal particles from entering the battery and causing a short circuit between the positive and negative electrodes, batteries require a high degree of structural sealing. In the related technologies known to the inventors, electrolyte filling is usually performed during the production stage. After electrolyte filling, laser welding is typically used to seal the filling hole to ensure battery sealing.

[0057] This type of battery is difficult to replenish during use. If you want to replenish the liquid, you need to damage the laser weld structure, which is difficult to reseal and will cause irreversible damage to the battery structure, affecting the battery's performance.

[0058] In view of this, this application provides a battery cell with a detachable electrolyte injection component, which facilitates secondary electrolyte injection into the battery. The process of injecting the required amount of electrolyte into the battery through a pre-drilled injection hole is divided into primary and secondary electrolyte injection. Secondary electrolyte injection can also be referred to as replenishment electrolyte injection, further electrolyte injection, etc. Secondary electrolyte injection refers to the process of replenishing or replacing the electrolyte in the battery, or adding or supplementing the battery with any solid, liquid, or gas. By enabling convenient secondary electrolyte injection, this application can effectively slow down the rate of cell capacity reduction and extend battery life.

[0059] During battery use, the electrolyte undergoes an electrochemical reaction inside the battery, thus requiring the battery to be sealed to prevent electrolyte leakage. Therefore, in the end cap assembly embodiment provided in this application, the end cap assembly includes a seal for sealing the electrolyte injection hole and a cover for fixing the seal. By providing the seal, the electrolyte injection hole can be effectively sealed, while the cover ensures the stability of the seal and prevents it from detaching from the electrolyte injection hole.

[0060] As part of the invention process of this application, the inventors also discovered that during secondary electrolyte filling, the filling hole is generally opened first, then electrolyte is injected into the battery through the filling hole, and finally the filling hole is sealed. Specifically, when opening the filling hole, the cover needs to be removed first, and then the seal needs to be removed; while when sealing the filling hole, the seal needs to be installed first, and then the cover needs to be installed. It is evident that the operation steps for opening and sealing the filling hole are relatively complex.

[0061] After discovering the complexity of the operation steps for opening and sealing the injection hole, the inventors conducted careful analysis and research. They found that a significant reason for the complexity was that the seal and the cover were separate structures. When installing or removing the seal and the cover, each part had to be installed or removed individually. For battery cells, the requirements for sealing performance are extremely high, so the positioning accuracy of the seal and the cover also requires high precision during assembly. Installing or removing the seal and the cover individually would inevitably increase the difficulty of assembly and disassembly, making the process more complex.

[0062] Based on the above findings, this application proposes an end cap assembly, a battery cell, a battery, and an electrical device that allows the seal and the cover to be rotatably connected. During secondary electrolyte injection, the seal and the cover can be sealed together as a whole at the first hole or detached from the first hole to close or open the first hole, thereby achieving secondary electrolyte injection. This simplifies the secondary electrolyte injection process, shortens the operation time, and improves operational efficiency. Furthermore, it effectively ensures a sealing effect, prevents electrolyte leakage from the battery cell, and improves the performance and lifespan of the battery cell.

[0063] Based on the above ideas, this application provides an end cap assembly, a housing assembly, a battery cell, a battery, an electrical device, a liquid injection method, and a liquid injection device.

[0064] The electrical device includes a battery cell 600 for providing electrical power to the device, such as Figure 1-A As shown, the electrical device can be a vehicle 100, such as a new energy vehicle, which can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle; or the electrical device can be a drone or a ship. The vehicle 100 includes a motor 200, a controller 300, and a battery 400. The motor 200 is used to drive the vehicle's movement, the controller 300 can control the vehicle's forward and reverse movements and its speed, and the battery 400 provides electric power to the vehicle, which can be used to drive the motor 200 to rotate. The motor 200 drives the wheels to rotate, thus driving the vehicle 100.

[0065] The battery cell 600 capable of secondary electrolyte injection can reduce the frequency of battery cell replacement in electrical devices, save costs, and improve the reliability and power performance of the device. The device using the battery cell 600 provided in this application can also simplify the secondary electrolyte injection process, shorten operation time, and improve the efficiency of secondary electrolyte injection.

[0066] In order to achieve higher battery power to meet usage requirements, such as Figure 1-BAs shown, a battery 400 may be installed in the electrical device. In some embodiments, the battery 400 may include a plurality of battery cells 600. The plurality of battery cells 600 may be directly assembled into a battery, or they may first be assembled into a battery module 500, and then the battery module 500 may be assembled into a battery. The battery 400 may include a first housing 401 and a second housing 402, wherein the first housing 401 and the second housing 402 are interlocked, and the plurality of battery cells 600 are arranged within the space enclosed by the first housing 401 and the second housing 402.

[0067] like Figure 1-C As shown, the battery module 500 includes multiple battery cells 600, which can be connected in series, parallel, or mixed connections to achieve a larger capacity or power. For example, as Figure 1-C As shown, the battery cell 600 can be placed upright, with the height direction of the battery cell 600 aligned with the vertical direction, and multiple battery cells 600 can be arranged side by side along the width direction; or the battery cell 600 can be placed flat, with the width direction of the battery cell 600 aligned with the vertical direction, and multiple battery cells 600 can be stacked at least one layer along the width direction, with each layer including multiple battery cells 600 spaced apart along the length direction.

[0068] To enable those skilled in the art to clearly understand the improvements of this application, the overall structure of the battery cell 600 will first be described.

[0069] like Figure 1-D As shown, the battery cell 600 includes an end cap assembly 10, an adapter 20, an electrode assembly 30, and a housing 40. The electrode assembly 30 includes tabs 301. The adapter 20 is connected to the electrode assembly 30. The electrode assembly 30 is disposed within the housing 40, and the housing 40 is filled with electrolyte. The top of the housing 40 has an opening 41, which the end cap assembly 10 closes, sealing the adapter 20 and the electrode assembly 30 inside the housing 40. The housing 40 can be square, cylindrical, or other shapes.

[0070] Depending on the actual usage requirements, the electrode assembly 30 can be configured as a single unit or multiple units. For example... Figure 1-DAs shown, at least two independently wound electrode assemblies 30 can also be provided within the battery. The electrode assembly 30 can be formed by winding or stacking a first electrode, a second electrode, and a separator located between the first and second electrodes together to form a main body, wherein the separator is an insulator between the first and second electrodes. The main body has two opposing end faces. In this embodiment, the first electrode is exemplarily described as a positive electrode and the second electrode as a negative electrode. A positive electrode active material is coated on the coating area of ​​the positive electrode, and a negative electrode active material is coated on the coating area of ​​the negative electrode. Multiple uncoated areas extending from the coating area of ​​the main body are stacked as tabs. The electrode assembly 30 includes two tabs 301, namely a positive tab and a negative tab. The positive tab extends from the coating area of ​​the positive electrode, and the negative tab extends from the coating area of ​​the negative electrode.

[0071] End cap assembly 10 is disposed on top of electrode assembly 30, such as Figure 1-D and Figure 2 As shown, the end cap assembly 10 includes an end cap 1 and two electrode terminals 5, which are a positive terminal and a negative terminal, respectively. Each electrode terminal 5 is provided with a corresponding adapter 20, which is located between the end cap assembly 10 and the electrode assembly 30. The end cap 1 has mounting holes corresponding to the electrode terminals 5, and the electrode terminals 5 are fixed in the corresponding mounting holes. A sealing ring may be provided between the electrode terminal 5 and the mounting hole. For example, Figure 1-D The tab 301 of the middle electrode assembly 30 is located at the top. The positive tab is connected to the positive terminal through an adapter 20, and the negative tab is connected to the negative terminal through another adapter 20.

[0072] Optionally, in some other embodiments, the battery cell 600 may include two end cap assemblies 10, respectively disposed at both ends of the housing 40, and each end cap assembly 10 is provided with an electrode terminal 5.

[0073] An explosion-proof component 6 can also be provided on the end cap 1 to release the gas inside the battery cell 600 in a timely manner when there is too much gas inside, thus preventing an explosion. The end cap 1 has a vent hole, which can be located at the middle of the end cap 1 along its length, between two mounting holes for mounting electrode terminals 5. Under normal conditions, the explosion-proof component 6 is sealed and installed in the vent hole. Gas is generated during charging and discharging of the battery cell 600. When the gas pressure inside the casing rises above a preset value, the explosion-proof component 6 opens, releasing the gas outwards. The explosion-proof component 6 can also be used to prevent explosion when the temperature inside the battery cell 600 becomes too high, achieving a cooling and explosion-proof effect by releasing the gas inside the battery cell.

[0074] In some embodiments, such as Figure 2As shown, the battery cell 600 is provided with a first hole 11 for injecting electrolyte into the interior of the battery cell 600, and the battery cell 600 also includes an injection component for sealing the first hole 11.

[0075] After describing the overall structure and application of the battery cell 600, the liquid injection component of this application will be described in detail below. First, the liquid injection component is provided on the end cap 1 as an example. Based on this structure, this application provides several embodiments. The common features of each embodiment are given below.

[0076] like Figures 1-D to 25 As shown, this application provides an end cap assembly 10 for a battery cell 600. In some embodiments, the end cap assembly 10 includes an end cap 1, a seal 2, and a cover 3.

[0077] like Figure 2 As shown, the end cap 1 has a first hole 11 for injecting electrolyte. The first hole 11 can be a round hole, an elliptical hole, a polygonal hole, or a hole of other shapes. The first hole 11 can be set along the height direction of the battery cell 600, that is, along the height direction of the end cap 1, or it can be set at an angle relative to the height direction of the end cap 1. The first hole 11 can be set between the mounting hole for mounting the electrode terminal 5 and the vent hole for mounting the explosion-proof component 6.

[0078] The seal 2 is used to seal the first hole 11. The seal 2 can be placed around the first hole 11 or inserted into the first hole 11 to effectively seal the first hole 11 and prevent the electrolyte in the battery cell 600 from leaking through the first hole 11.

[0079] The cover 3 is used to cover at least part of the seal 2 to prevent the seal 2 from detaching from the end cap 1. The cover 3 can press down on the seal 2, causing the seal 2 to deform and improve the sealing effect, or it can only contact the seal 2 to restrict its freedom of movement in the height direction; when the seal 2 is tightly fitted with the first hole 11 and can independently close the first hole 11, the cover 3 can also be spaced apart from the seal 2 in the height direction. The cover 3 can completely cover the seal 2 to apply pressure to the seal 2, limit it, or prevent external impurities from entering the interior of the battery cell 600; when the seal 2 is tightly fitted with the first hole 11 and can independently close the first hole 11, the cover 3 can also partially cover the seal 2.

[0080] The cover 3 is rotatable relative to the end cap 1, and the cover 3 is detachably connected to the end cap 1 by rotation. For example, the cover 3 is rotatable in a plane perpendicular to the height direction, and the axis of rotation can be the axis of the first hole 11.

[0081] This application allows for the separation of the cover 3 from the end cap 1 by rotating the cover 3, thus enabling secondary electrolyte injection. Through convenient secondary electrolyte injection, this application can effectively mitigate the capacity reduction of individual battery cells (600 mAh / g) and extend battery life.

[0082] Furthermore, the liquid injection component is detachable. After detachment, the first hole 11 connects the interior of the housing 40 to the external atmosphere, allowing gas or air bubbles between the electrodes to be discharged. By discharging air bubbles between the electrodes, the gap between them is shortened, improving the cycle performance of the battery cell 600 and further extending its lifespan. Discharging gas from the battery cell 600 housing also releases pressure within the housing 40, reducing the continuous stress on the explosion-proof component 6 and lowering the risk of creep rupture of the explosion-proof component 6 leading to leakage or moisture ingress, thus shortening the battery cell's lifespan. This further extends the cell's lifespan and reduces the force exerted on other structures by the expansion of the battery cell 600 due to excessive gas buildup, preventing structural damage and further extending the battery's lifespan.

[0083] This application achieves the connection or separation of the cover 3 and the end cap 1 by rotating the cover 3, thereby closing and opening the first hole 11. This creates a detachable structure between the cover 3 and the end cap 1. Opening the cover 3 does not damage the electrolyte filling structure, and the first hole 11 can be reliably closed after secondary electrolyte filling, ensuring the reliability of the battery cell after the second electrolyte filling. Therefore, the appearance of the battery cell 600 remains consistent with that before electrolyte filling, and its use after secondary electrolyte filling is not affected. Furthermore, because the first hole 11 is closed directly by rotating the cover 3, laser welding is unnecessary for sealing the first hole 11, reducing the cleaning steps required before laser welding and improving battery production efficiency.

[0084] like Figure 3 As shown, one of the seal 2 and the cover 3 is provided with a second hole 21, and the other of the seal 2 and the cover 3 is provided with a boss 31. The boss 31 is used to be inserted into the second hole 21 and the boss 31 and the second hole 21 can rotate relative to each other to realize the rotatable connection between the seal 2 and the cover 3.

[0085] Specifically, in some embodiments, the seal 2 has a second hole 21, and the cover 3 has a boss 31, which is inserted into the second hole 21 to achieve a rotatable connection between the seal 2 and the cover 3. In other embodiments, the seal 2 has a boss 31, and the cover 3 has a second hole 21, which is inserted into the second hole 21 to achieve a rotatable connection between the seal 2 and the cover 3.

[0086] By connecting the seal 2 and the cover 3, the seal 2 and the cover 3 can be installed or removed as a whole when opening or closing the first hole 11, simplifying the operation steps, shortening the operation time, and improving the operation efficiency. After installing the seal 2 and the cover 3, impurities can be prevented from entering the interior of the battery cell 600 through the first hole 11.

[0087] Furthermore, the cover 3 is rotatable relative to the end cap 1. By setting the seal 2 and the cover 3 to be rotatably connected, when the cover 3 is rotated, the cover 3 can avoid the seal 2 from being linked together. This helps to keep the seal 2 and the end cap 1 relatively fixed, and prevents the seal 2 and the end cap 1 from rotating relative to each other and causing wear, thereby reducing the sealing effect.

[0088] The following is in conjunction with the appendix Figures 4-19B The mating structure of the seal 2 and the cover 3 in this application is described in detail.

[0089] like Figures 4-11 As shown, in some embodiments, the boss 31 and the second hole 21 are interference-fitted to achieve the connection between the two.

[0090] The boss 31 and the second hole 21 are fitted with an interference fit, which not only connects the seal 2 and the cover 3, but also allows relative rotation between the seal 2 and the cover 3. Achieving a rotatable connection between the seal 2 and the cover 3 through an interference fit eliminates the need for additional components or structures, resulting in lower manufacturing costs.

[0091] The boss 31 and the second hole 21 are interference fit, that is, the boss 31 and the second hole 21 are tight fit. There is an interference between the dimensions of the boss 31 and the second hole 21. The tolerance zone of the second hole 21 is below the tolerance zone of the boss 31.

[0092] In some embodiments, the boss 31 is a rotating body. The boss 31 is rotatable relative to the seal 2 within the second hole 21. By configuring the boss 31 as a rotating body, a rotatable connection can be achieved between the seal 2 and the cover 3. The shape of the second hole 21 matches the shape of the boss 31.

[0093] The boss 31 is a rotating body, specifically a cylinder, a sphere, or a part of a sphere.

[0094] The shape of the boss 31 matches the shape of the second hole 21 to achieve an interference fit. For example, as Figures 4-11 As shown, the boss 31 is cylindrical, and the second hole 21 is cylindrical to mate with the boss 31. Alternatively, as... Figures 12-14 As shown, the boss 31 is shaped like a frustum, and the second hole 21 is also shaped like a frustum that mates with the boss 31. Alternatively, as... Figures 15-18As shown, the boss 31 is shaped like a stepped cylinder, and the second hole 21 is shaped like a stepped circle that mates with the boss 31. Several different embodiments of the boss 31 and the second hole 21 will be described in detail below.

[0095] like Figures 12-18 As shown, in some embodiments, the boss 31 includes a first insertion portion 311, and the second hole 21 has a first receiving portion 212 on its hole wall. The first insertion portion 311 is received in the first receiving portion 212 to restrict the seal 2 and the cover 3 from detaching.

[0096] By providing a first insertion part 311 and a first receiving part 212, the first insertion part 311 is inserted into the first receiving part 212. Through the cooperation of the first insertion part 311 and the first receiving part 212, the seal 2 and the cover 3 can be prevented from separating from each other, ensuring a stable connection between the seal 2 and the cover 3.

[0097] The boss 31 may include only the first insertion portion 311, or it may include other portions besides the first insertion portion 311. The second hole 21 may include only the first receiving portion 212, or it may include other portions besides the first receiving portion 212.

[0098] The shapes of the first insertion part 311 and the first receiving part 212 are matched, and they cooperate with each other to prevent the seal 2 and the cover 3 from separating. Since the battery cell 600 may vibrate during use, maintaining the connection between the seal 2 and the cover 3 helps the battery cell 600 resist the loosening problem caused by vibration and improves the service life of the battery cell 600.

[0099] like Figures 12-14 As shown, in some embodiments, in a direction perpendicular to the axis of the second hole 21, the cross-sectional area of ​​the first receiving portion 212 gradually increases in the direction away from the inserted end of the second hole 21, and the first insert portion 311 cooperates with the first receiving portion 212 to restrict the seal 2 and the cover 3 from disengaging.

[0100] The cross-sectional area of ​​the first receiving portion 212 gradually increases in the direction away from the inserted end of the second hole 21, which increases the difficulty for the first insertion portion 311 to detach from the first receiving portion 212, thereby restricting the detachment of the sealing member 2 and the cover 3. In the direction parallel to the axis of the second hole 21, the cross-section of the first receiving portion 212 is trapezoidal.

[0101] like Figures 15-18As shown, the boss 31 includes a first insertion portion 311 and a second insertion portion 312, both of which are cylindrical. The second hole 21 includes a third extension portion 216 and a first receiving portion 212. The third extension portion 216 mates with the second insertion portion 312, and the first receiving portion 212 mates with the first insertion portion 311. The diameter of the first insertion portion 311 is larger than the diameter of the second insertion portion 312, and the diameter of the first receiving portion 212 is larger than the diameter of the third extension portion 216. Therefore, the mating of the first insertion portion 311 and the first receiving portion 212 can prevent the seal 2 from disengaging from the cover 3.

[0102] like Figures 4-18 As shown, in some embodiments, the second hole 21 is a blind hole, that is, the end of the second hole 21 away from the cover 3 is closed. This structure can effectively prevent impurities from entering the interior of the battery cell 600 through the second hole 21, and can also effectively prevent the electrolyte in the battery cell 600 from leaking through the second hole 21.

[0103] In some embodiments, the seal 2 and the end cap 1 are fixed relative to each other in the circumferential direction of the first hole 11.

[0104] The seal 2 and the end cap 1 are kept relatively fixed in the circumferential direction. This can prevent the seal 2 from rotating with the end cap 1 when the cover 3 rotates relative to the end cap 1, thereby reducing wear between the seal 2 and the end cap 1 and reducing the impact on the sealing effect.

[0105] In the battery cell 600 provided in this application, the seal 2 seals the first hole 11 and presses against the lower side of the end cap 1. In actual use, when the cover 3 rotates relative to the end cap 1, if the cover 3 covers most or completely the seal 2, it may be difficult to visually determine whether the seal 2 located under the cover 3 has rotated relative to the end cap 1. To solve this problem, marks can be made on the outer surface of the seal 2 and the wall of the first hole 11. Before rotating the cover 3, the marks of the seal 2 and the first hole 11 at their respective mating positions are recorded. After rotating the cover 3, the cover 3 is reopened, and the relative positions of the seal 2 and the first hole 11 can be determined by checking the marked positions. The marks can be made by drawing lines, affixing labels, or other methods.

[0106] In some embodiments, the axis of rotation of the cover 3 relative to the seal 2 is collinear with the axis of the first hole 11.

[0107] If the axis of rotation of the cover 3 relative to the seal 2 is not collinear with the axis of the first hole 11, the seal 2 will rotate due to eccentricity when the cover 3 rotates relative to the seal 2, causing friction between the seal 2 and the end cap 1. Therefore, setting the axis of rotation of the cover 3 relative to the seal 2 to be collinear with the axis of the first hole 11 can effectively ensure that the seal 2 does not rotate with the cover 3 when the cover 3 rotates relative to the end cap 1, thereby reducing friction between the seal 2 and the end cap 1.

[0108] In some embodiments, the seal 2 includes a sealing post 22 inserted into the first hole 11. The seal 2 effectively seals the first hole 11 through the sealing post 22, preventing electrolyte leakage and the entry of impurities.

[0109] The sealing post 22 is inserted into the first hole 11, which can achieve a better sealing effect on the first hole 11.

[0110] In some embodiments, the sealing post 22 is a non-rotating body, and the shape of the first hole 11 matches the seal 2.

[0111] Setting the sealing post 22 as a non-rotating body can effectively ensure the relative fixation between the sealing element 2 and the end cap 1, preventing relative rotation between the sealing element 2 and the end cap 1 and thus preventing wear. The shape of the first hole 11 matches the sealing element 2, which is beneficial for achieving a seal on the first hole 11.

[0112] like Figure 19A and 19B As shown, the cross-sectional shape of the sealing post 22 is elliptical, and the shape of the first hole 11 is set to match the sealing element 2. After the sealing post 22 matches the first hole 11, it cannot rotate in the first hole 11, thus achieving relative fixation between the sealing element 2 and the end cap 1.

[0113] In addition to the elliptical shape, in some other embodiments, the cross-sectional shape of the sealing post 22 can also be polygonal or irregular.

[0114] In some embodiments, the sealing post 22 is interference-fitted with the first hole 11. The interference fit between the sealing post 22 and the first hole 11 means that the sealing post 22 and the first hole 11 are tightly fitted, with an interference amount between their dimensions, and the tolerance zone of the first hole 11 is below the tolerance zone of the sealing post 22.

[0115] By setting the fit between the sealing post 22 and the first hole 11 as an interference fit, the difficulty of the sealing post 22 rotating in the first hole 11 can be increased, thereby achieving relative fixation between the sealing element 2 and the end cover 1.

[0116] In some embodiments, the sealing post 22 is interference-fitted with the first hole 11, and the boss 31 is interference-fitted with the second hole 21. Furthermore, the frictional force between the sealing post 22 and the first hole 11 is greater than the frictional force between the boss 31 and the second hole 21. With this configuration, when an external force applied to the cover 3 causes the cover 3 to rotate relative to the sealing member 2, this external force is insufficient to overcome the frictional force between the sealing member 2 and the end cap 1, thus preventing relative rotation between the sealing member 2 and the end cap 1. Therefore, the relative fixation of the sealing member 2 and the end cap 1 can be ensured, reducing wear between them.

[0117] In some embodiments, the sealing post 22 is interference-fitted with the first hole 11, the boss 31 is interference-fitted with the second hole 21, and the coefficient of friction of the contact surface between the sealing post 22 and the first hole 11 is greater than the coefficient of friction of the contact surface between the boss 31 and the second hole 21.

[0118] When an interference fit is used between the sealing post 22 and the first hole 11, and between the boss 31 and the second hole 21, the coefficient of friction of the contact surface between the sealing post 22 and the first hole 11 is set to be greater than the coefficient of friction of the contact surface between the boss 31 and the second hole 21. When the external force applied to the cover 3 is sufficient to make the cover 3 rotate relative to the sealing element 2, due to the different coefficients of friction, the force generated by the rotation of the cover 3 on the sealing element 2 is insufficient to make the sealing element 2 rotate relative to the end cover 1. Therefore, the relative fixation of the sealing element 2 and the end cover 1 can be guaranteed, and the wear between the sealing element 2 and the end cover 1 can be reduced.

[0119] In other embodiments, the sealing post 22 is interference-fitted with the first hole 11, the boss 31 is interference-fitted with the second hole 21, and the interference between the sealing post 22 and the first hole 11 is greater than the interference between the boss 31 and the second hole 21.

[0120] The large interference between the sealing post 22 and the first hole 11 results in a large frictional force between them. This means that the sealing element 2 and the end cap 1 need to be subjected to a greater external force than the relative rotation between the cover body 3 and the sealing element 2 in order to rotate. Therefore, when the cover body 3 rotates relative to the sealing element 2, the sealing element 2 and the end cap 1 can be relatively fixed.

[0121] Under the premise that the frictional force between the sealing post 22 and the first hole 11 is greater than the frictional force between the boss 31 and the second hole 21, in some embodiments where the interference fit between the sealing post 22 and the first hole 11 is greater than the interference fit between the boss 31 and the second hole 21, the coefficient of friction of the contact surface between the sealing post 22 and the first hole 11 can be equal to or greater than the coefficient of friction of the contact surface between the boss 31 and the second hole 21.

[0122] Under the premise that the frictional force between the sealing post 22 and the first hole 11 is greater than the frictional force between the boss 31 and the second hole 21, in some embodiments where the coefficient of friction of the contact surface between the sealing post 22 and the first hole 11 is greater than the coefficient of friction of the contact surface between the boss 31 and the second hole 21, the interference fit between the sealing post 22 and the first hole 11 can be equal to or greater than the interference fit between the boss 31 and the second hole 21.

[0123] In some embodiments, the sealing post 22 is interference-fitted with the first hole 11, and the boss 31 is interference-fitted with the second hole 21. The coefficient of friction between the contact surfaces of the sealing post 22 and the first hole 11 is greater than that between the contact surfaces of the boss 31 and the second hole 21, and the interference amount between the sealing post 22 and the first hole 11 is greater than that between the boss 31 and the second hole 21. This structure can more effectively keep the seal 2 and the end cap 1 relatively fixed during the rotation of the cover 3 relative to the seal 2.

[0124] In some embodiments, the seal 2 further includes a thrust plate 23 connected to the sealing post 22. The thrust plate 23 is located between the cover 3 and the end cap 1, and the thrust plate 23 engages with the end face of the first hole 11.

[0125] The thrust block 23 has a preset thickness and can be sealed to the outer end face of the first hole 11. In the direction perpendicular to the axis of the first hole 11, the cross-sectional area of ​​the thrust block 23 is greater than or equal to the cross-sectional area of ​​the first hole 11. By setting the thrust block 23, the outer end of the first hole 11 can be effectively sealed, preventing electrolyte from flowing out through the gap between the sealing post 22 and the first hole 11, and also preventing impurities from entering the interior of the battery cell 600 through the gap between the sealing post 22 and the first hole 11.

[0126] In some embodiments, the mating surface between the thrust plate 23 and the end face of the first hole 11 is a plane. This structure facilitates a tight contact between the thrust plate 23 and the end face of the first hole 11, achieving an effective seal between the thrust plate 23 and the end face of the first hole 11, preventing electrolyte leakage or impurities from entering.

[0127] The following describes the mating structure between the cover 3 and the end cap 1 in this application.

[0128] like Figure 4 As shown, in some embodiments, the end cap 1 is provided with a second receiving portion 12 arranged circumferentially along the first hole 11. The second receiving portion 12 is used to receive at least a portion of the cover body 3 to limit the cover body 3. The second receiving portion 12 is located on the side of the end cap 1 away from the interior of the battery cell 600.

[0129] The second receiving portion 12 can accommodate a part of the cover 3 to restrict the cover 3, limiting its degree of freedom in the height direction and preventing the cover 3 from detaching from the end cap 1, thus achieving relative fixation between the cover 3 and the end cap 1. At the same time, the cover 3 can also at least partially cover the sealing element 2. Therefore, after the cover 3's degree of freedom in the height direction is restricted by the end cap 1, the sealing element 2 is also pressed under the cover 3, thus also achieving fixation of the sealing element 2.

[0130] The second receiving portion 12 is located on the side of the end cap 1 away from the housing 40 and is disposed circumferentially along the first hole 11. The second receiving portion 12 can be a cavity extending circumferentially along a portion of the first hole 11. There is a preset distance between the second receiving portion 12 and the surface of the end cap 1 near the interior of the housing 40. The size of the preset distance is not limited. For example, the second receiving portion 12 can be disposed in the upper region, middle region or lower region of the end cap 1, such that at least a portion of the end cap 1 is located between the second receiving portion 12 and the electrode assembly 30, rather than the second receiving portion 12 being directly formed on the bottom surface of the end cap 1.

[0131] like Figures 4-18 As shown, in some embodiments, the cover 3 is rotatable relative to the end cap 1 and includes a limiting part 33. When the cover 3 is rotated to the first position, the limiting part 33 is located in the second receiving part 12 to restrict the separation of the cover 3 from the end cap 1. When the cover 3 is rotated to the second position, the limiting part 33 and the second receiving part 12 are misaligned along the circumferential direction of the first hole 11 to achieve the separation of the cover 3 from the end cap 1.

[0132] By providing a limiting part 33 that cooperates with the second receiving part 12, a detachable connection can be achieved between the end cap 1 and the cover body 3. The cover body 3 includes a cover body main body 32 for covering at least a portion of the sealing element 2; for example, the cover body main body 32 may be disc-shaped or annular. The limiting part 33 is provided on the circumferential side of the cover body main body 32 and extends radially outward. The number of limiting parts 33 matches the number of second receiving parts 12. Figures 4-18 In the illustrated embodiment, the side of the main body 32 of the cover is provided with two spaced-apart limiting portions 33, and the end cap 1 is provided with two second receiving portions 12, with the two limiting portions 33 corresponding to the two second receiving portions 12 one-to-one. In other embodiments, the number of second receiving portions 12 and limiting portions 33 may also be two or more, such as three or four.

[0133] By providing multiple limiting parts 33, the cover 3 has multiple limiting supports in the first position, which can be stably engaged by the second receiving part 12 and reduce the engaging force borne by the limiting parts 33, thereby ensuring the strength of the limiting parts 33. For example, the multiple limiting parts 33 can be evenly distributed along the circumference of the cover body 32, which can make the force distribution of the cover 3 more balanced along the entire circumference, prevent the cover 3 from tilting, and facilitate the smooth rotation of the cover 3 from the first position to the second position during secondary liquid injection. For the structure where the cover 3 presses against the seal 2, it can also prevent the limiting parts 33 from scratching the seal 2 during rotation.

[0134] A locking structure is formed between the limiting part 33 and the second receiving part 12. When the cover 3 is rotated to the first position, the limiting part 33 is partially or completely located in the second receiving part 12 to restrict the separation of the cover 3 from the end cap 1, thereby closing the first hole 11. When the cover 3 is rotated to the second position in a clockwise or counterclockwise direction, the limiting part 33 and the second receiving part 12 are misaligned along the circumference of the first hole 11, and the limiting part 33 is completely disengaged from the second receiving part 12 to achieve the separation of the cover 3 from the end cap 1. Electrolyte can be injected in this state.

[0135] The cover 3 is rotated to limit or separate from the second receiving part 12. During the rotation, friction may occur between the limiting part 33 and the inner wall of the second receiving part 12, generating metal particles. Since the second receiving part 12 is located on the side of the end cover 1 away from the housing 40 in this application, the metal particles generated during the rotation will not fall directly into the housing 40 and cause a short circuit in the battery cell 600, further improving the safety of the battery cell 600.

[0136] The circumferential extension length of the limiting part 33 along the first hole 11 and the radial extension width of the first hole 11 ensure the strength of the locking structure, preventing damage to the locking structure even with frequent disassembly and assembly. Furthermore, when the battery cell 600 is used in the vehicle 100, the vehicle 100 vibrates during operation. This application, by increasing the locking strength between the limiting part 33 and the second receiving part 12, can prevent damage to the limiting part 33 and the second receiving part 12 due to long-term vibration, thereby ensuring the reliability and service life of the battery cell 600.

[0137] This application achieves the engagement or disengagement of the limiting part 33 and the second receiving part 12 by rotating the cover 3. The structure is simple, the requirement for fitting accuracy is low, and it can be reused repeatedly. In terms of processing, the limiting part 33 on the cover 3 and the second receiving part 12 on the end cap 1 are easy to process and are suitable for lithium-ion batteries with small overall size. In terms of assembly and maintenance, the disassembly and assembly of the cover 3 is easy, which can improve the assembly efficiency of the battery during production and shorten the maintenance time during secondary electrolyte filling.

[0138] In some embodiments, the boss 31 and the second hole 21 are configured to be rotatable relative to each other at least during the process of rotating the cover 3 from the first position to the second position.

[0139] The boss 31 and the second hole 21 can be configured to be partially rotatable relative to each other in the circumferential direction of rotation. For example, a limiting boss can be set inside the second hole 21 to restrict the circumferential rotation of the boss 31. Alternatively, the boss 31 and the second hole 21 can be configured to be rotatable relative to each other in the circumferential direction of rotation. Setting the boss 31 and the second hole 21 to be partially rotatable relative to each other in the circumferential direction effectively limits the range of rotation, allowing them to rotate within a preset range, which is beneficial for controlling the extreme positions of rotation. Setting the boss 31 and the second hole 21 to be rotatable relative to each other in the circumferential direction increases the flexibility of rotation and makes operation more convenient.

[0140] In some embodiments, the end cap 1 further includes a guide portion 13 communicating with the second receiving portion 12, and a limiting portion 33 is used to enter the second receiving portion 12 via the guide portion 13, or to separate from the end cap 1 via the guide portion 13. By providing the guide portion, the limiting portion 33 can enter the second receiving portion 12 or separate from the end cap 1 more smoothly, improving the convenience of operation and thus improving the efficiency of operation.

[0141] The guide portion 13 forms a channel communicating between the second receiving portion 12 and the outside of the end cap 1. For example, multiple second receiving portions 12 are provided circumferentially, and the guide portion 13 is an opening area formed between adjacent second receiving portions 12. When the cap 3 is in the second position, the limiting portion 33 is circumferentially misaligned with the second receiving portions 12 and located within the guide portion 13. Alternatively, only one second receiving portion 12 is provided circumferentially, and the guide portion 13 is an opening area circumferentially other than the second receiving portions 12.

[0142] The circumferential length of the guide portion 13 can be greater than the circumferential length of the limiting portion 33, but not exceed the circumferential length of the second receiving portion 12, so as to maximize the engagement length between the limiting portion 33 and the second receiving portion 12 and improve the limiting stability. The circumferential length of the guide portion 13 should allow the limiting portion 33 to smoothly enter the guide portion 13.

[0143] In some embodiments, the end cap 1 is provided with a first groove 14, which communicates with the first hole 11. The opening area of ​​the first groove 14 is larger than the opening area of ​​the first hole 11. The first groove 14 is used to accommodate the cover body 3. The first groove 14 communicates with the guide portion 13. Placing the cover body 3 in the first groove 14 and rotating the cover body 3 can allow the cover body 3 to enter the second receiving portion 12 through the guide portion 13.

[0144] In some embodiments, the end cap 1 includes an end cap body 1A and a mounting member 4. The mounting member 4 is disposed on the surface of the end cap body 1A and surrounds the first hole 11. The second receiving portion 12 is disposed on the mounting member 4 or the second receiving portion 12 is formed by the mounting member 4 and the end cap body 1A enclosing each other. The mounting member 4 is installed in the first groove 14.

[0145] Since the end cap 1 is a thin plate structure that is not easy to process into complex structures, the second receiving part 12 can be easily formed by setting the mounting part 4, which can reduce the processing difficulty of the end cap 1.

[0146] The following is in conjunction with the appendix Figures 20A-21B The specific structure of mounting component 4 in this application will be described.

[0147] like Figure 20A As shown, this is a front structural schematic diagram of the mounting component 4 in some embodiments; as Figure 20B As shown, this is a schematic diagram of the rear structure of the mounting component 4 in some embodiments; as Figure 21A The image shown is a top view of the mounting component 4 in some embodiments; as shown... Figure 21B The figure shown is a cross-sectional view of the mounting component 4 in some embodiments.

[0148] The second receiving portion 12 is disposed on the mounting component 4. The mounting component 4 includes a mounting ring 41 and a limiting platform 43. The limiting platform 43 is connected to the inner wall of the mounting ring 41 and extends radially inward. The mounting ring 41 is fixed to the end cap body 1A, and the second receiving portion 12 is formed between the limiting platform 43 and the end cap body 1A. The mounting ring 41 may be a circular ring structure, and the first groove 14 is disposed at the center of the mounting ring 41.

[0149] The second receiving portion 12 includes a limiting wall 123 and a side wall 124 connected to the limiting wall 123. The bottom surface of the limiting platform 43 serves as the limiting wall 123. When the cover 3 rotates to the first position, the limiting wall 123 abuts against the limiting portion 33. The limiting wall 123 is a top wall, which can restrict the degree of freedom of the cover 3 to move upward in the height direction, thereby restricting the separation of the cover 3 from the end cap 1.

[0150] The limiting wall 123 is provided with an inclined surface 122, which is configured such that the distance between the inclined surface 122 and the cover 3 gradually decreases along the rotational direction of the cover 3 from the second position to the first position. The inclined surface 122 can be provided at one or both ends of the second receiving portion 12 in the circumferential direction, so that the limiting portion 33 can smoothly enter the second receiving portion 12. For example, the inclined surface 122 can be a plane or an arc surface, etc.

[0151] By setting the inclined surface 122, the limiting part 33 can smoothly enter the second receiving part 12 without the need for alignment adjustment, which can improve assembly efficiency and prevent the limiting part 33 from colliding with the entrance of the second receiving part 12, thereby increasing the service life of the liquid injection component and reducing the generation of metal chips.

[0152] The second receiving portion 12 is provided with a stop portion 125, which is configured to limit the maximum rotational stroke of the limiting portion 33. Each second receiving portion 12 may be provided with a stop portion 125. The stop portion 125 can block the rotation of the limiting portion 33 and prevent the limiting portion 33 from rotating directly out of the second receiving portion 12.

[0153] When the maximum rotation stroke is reached, the circumferential side of the limiting part 33 is completely in contact with the stop part 125. For example, two limiting parts 33 are evenly provided circumferentially on the main body part 32 of the cover, and the two circumferential side surfaces of the limiting parts 33 are parallel to the central plane of the cover 3. Correspondingly, the stop parts 125 of the two second receiving parts 12 are centrally symmetrical with respect to the central plane of the second hole 21, and the two stop parts 125 are parallel to each other. Optionally, the circumferential side surface of the limiting part 33 may also partially abut against the stop part 125.

[0154] To prevent the mounting component 4 from rotating circumferentially relative to the first groove 14 during installation, such as Figures 20A-21B The bottom of the mounting component 4 may be provided with a second groove 42, for example, the second groove 42 may be provided at the bottom of the mounting ring 41. Accordingly, such as Figure 22 As shown, a locking part 141 is provided at the connection between the bottom wall and the side wall of the first groove 14. The locking part 141 cooperates with the second groove 42 to restrict the circumferential rotation of the mounting component 4 relative to the first groove 14.

[0155] In some embodiments, the seal 2 may be deformable, and a highly elastic material resistant to electrolytes may be selected, such as rubber or other elastic plastics.

[0156] When the cover 3 needs to be installed, a downward force is applied to the cover 3. The deformation of the seal 2 creates a gap between the limiting part 33 and the limiting wall 123. At this time, the cover 3 is rotated so that the limiting part 33 smoothly enters the second receiving part 12. After reaching the first position, the cover 3 is released. The cover 3 moves upward under the elastic action of the seal 2 until the top surface of the limiting part 33 abuts against the limiting wall 123.

[0157] When it is necessary to disassemble the cover 3, a downward force is applied to the cover 3. The deformation of the seal 2 causes a gap to be created between the limiting part 33 and the limiting wall 123. At this time, the cover 3 is rotated so that the limiting part 33 is smoothly displaced circumferentially with the second receiving part 12 and is located entirely in the guide part 13. At this time, the second position is reached, and the cover 3 can be disassembled.

[0158] In some embodiments, a limiting structure is provided between the limiting portion 33 and the second receiving portion 12, configured to prevent the cover 3 from being misaligned and separated from the second receiving portion 12 when it is in the first position. If the device using the battery cell 600 experiences significant vibration or impact during operation, the limiting structure can reliably engage the limiting portion 33 and the second receiving portion 12 in the first position, preventing the limiting portion 33 from rotating circumferentially and disengaging from the second receiving portion 12. This makes the connection between the cover 3 and the end cap 1 more reliable, improves the sealing of the electrolyte, and thus ensures the reliability of battery operation.

[0159] like Figure 20A and Figure 21A As shown, the limiting structure includes a third receiving portion 332 and a limiting protrusion 121. The third receiving portion 332 is located on one of the limiting portion 33 and the second receiving portion 12, and can be a hole or groove, etc. The limiting protrusion 121 engages with the third receiving portion 332 and is located on the other of the limiting portion 33 and the second receiving portion 12. When the cover 3 is in the first position, under the elastic action of the sealing member 2, the third receiving portion 332 and the limiting protrusion 121 are locked together, preventing the limiting portion 33 and the second receiving portion 12 from rotating and loosening due to external forces such as vibration or impact; alternatively, the cover 3 is locked together through an interference fit between the third receiving portion 332 and the limiting protrusion 121.

[0160] like Figure 20A As shown, the limiting protrusion 121 is provided on the limiting wall 123 of the second receiving portion 12; as Figure 8 As shown, a third receiving portion 332 is provided on the top surface of the limiting portion 33. When the cover 3 is in the first position, the limiting protrusion 121 is embedded in the third receiving portion 332 to restrict the rotation of the cover 3.

[0161] In some embodiments, the seal 2 includes a sealing post 22 inserted into the first hole 11. The end of the sealing post 22 near the interior of the battery cell 600 is provided with a guide slope. The length of the guide slope along the axial direction of the first hole 11 is greater than the length of the mounting component 4 along the axial direction of the first hole 11. This configuration ensures that before inserting the sealing post 22 into the first hole 11, the contact between the sealing post 22 and the hole wall of the first hole 11 precedes the contact between the seal 2 and the outer surface of the end cap 1, thereby reducing wear between the seal 2 and the end cap 1 and ensuring the sealing effect of the seal 2. Simultaneously, the guide slope guides the insertion of the sealing post 22 into the first hole 11, improving ease of operation and thus increasing operational accuracy and efficiency.

[0162] The following is in conjunction with the appendix Figure 23 Another mating structure between the cover 3 and the end cap 1 in this application is described.

[0163] like Figure 23 As shown, the end cap 1 includes an end cap body 1A and an injection base 15. The end cap body 1A is provided with a first hole 11 and a first groove 14. The bottom of the first groove 14 is provided with a hole communicating with the first hole 11.

[0164] The liquid injection base 15 includes a bottom support plate 151 and a liquid injection portion 152 mounted on the bottom support plate 151. The bottom support plate 151 is disposed in a first groove 14, and the bottom surface of the bottom support plate 151 contacts the bottom surface of the groove 14. At least a portion of the liquid injection portion 152 is higher than the outer surface of the end cap 1 on the side away from the interior of the battery cell 600.

[0165] The first hole 11 includes a first hole section 11A on the injection base 15 and a second hole section 11B on the end cap body 1A, and the first hole section 11A and the second hole section 11B are connected. The second receiving part 12 is provided on the outer side of the injection part 152, and the inner side of the cap 3 is provided with a locking part. The cap 3 is in the shape of a circular cap.

[0166] The sealing post 22 is inserted into the first hole section 11A and the second hole section 11B. The bottom surface of the thrust plate 23 abuts against the top surface of the liquid injection section 152. The cover 3 covers the upper part of the seal 2. By rotating the cover 3, the engaging part enters the second receiving part 12. The engagement part and the second receiving part 12 cooperate to connect the cover 3 and the end cap 1. At the same time, the seal 2 is pressed between the cover 3 and the end cap 1 to fix the seal 2.

[0167] The number of engaging parts and second receiving parts 12 are equal, for example, one, two or three of each.

[0168] The following is in conjunction with the appendix Figures 4-19B Different embodiments of the mating structure between the seal 2 and the cover 3 in this application are described in detail.

[0169] like Figures 4-9 The diagram shown is a structural schematic of the first embodiment.

[0170] In the first embodiment, as Figure 5 and Figure 6 As shown, the seal 2 has a second hole 21, and the seal 2 includes a sealing post 22 and a thrust plate 23 connected to the sealing post 22. The sealing post 22 and the thrust plate 23 can be two independent parts connected to each other; the sealing post 22 and the thrust plate 23 can also be an integrally formed structure.

[0171] The second hole 21 extends from the end of the thrust plate 23 away from the sealing post 22 toward the sealing post 22. The second hole 21 penetrates the thrust plate 23 and extends to the sealing post 22. The second hole 21 is a blind hole.

[0172] The second hole 21 has a chamfer 211 at the end of the thrust plate 23 away from the sealing post 22. The chamfer 211 guides the boss 31 inserted into the second hole 21, improving assembly efficiency. The chamfer 211 is arc-shaped, and its opening area gradually increases in the direction away from the sealing post 22 to facilitate the insertion of the boss 31. In addition to the chamfer 211, the second hole 21 includes a cylindrical section of equal diameter and a reduced-diameter section, with the reduced-diameter section located at the end of the cylindrical section away from the chamfer 211.

[0173] In the first embodiment, the length of the second hole 21 is less than 50% of the overall length of the seal 2. The length of the second hole 21 is slightly greater than the length of the boss 31.

[0174] The sealing column 22 includes a sealing body portion 221 and a conical portion 222 connected to the sealing body portion 221. The sealing body portion 221 and the conical portion 222 can be two relatively independent parts connected to each other, or they can be integrally formed. The cross-sectional area of ​​the conical portion 222 gradually decreases in the direction away from the thrust plate 23. The end of the conical portion 222 away from the thrust plate 23 is a plane.

[0175] By setting the cone 222, the sealing post 22 can be guided when it is inserted into the first hole 11, which facilitates the insertion of the sealing post 22 and improves assembly efficiency.

[0176] The sealing post 22 is also provided with a weight-reducing recess 223, which can be provided on the sealing body 221. The weight-reducing recess 223 extends from the outer surface of the sealing body 221 in a direction close to the central axis of the sealing body 221. Multiple weight-reducing recesses 223 can be provided in the circumferential direction of the sealing post 22 to reduce the overall weight of the sealing element 2.

[0177] The thrust plate 23 is also cylindrical, and its height is less than that of the sealing column 22.

[0178] like Figures 7-9 As shown, the cover 3 has a boss 31, and the cover 3 includes a cover body 32 and a limiting part 33 connected to the cover body 32. The limiting part 33 and the cover body 32 can be two relatively independent parts connected to each other, or they can be integrally formed. In the first embodiment, two limiting parts 33 are connected to the outer periphery of the cover body 32.

[0179] The first end of the cover body 32 is provided with a third groove 321 extending from the end face of the first end toward the interior of the cover body 32. For example, the cross-sectional shape of the third groove 321 is hexagonal, which facilitates the rotation of the cover 32 using tools. The side of the limiting part 33 near the first end of the cover body 32 is provided with a third receiving part 332 extending from that side face toward the interior of the limiting part 33. For example, the cross-sectional shape of the third receiving part is elliptical.

[0180] A boss 31 is provided at the second end of the cover body 32 opposite to the first end. The second end of the cover body 32 is provided with a fourth receiving portion 331 extending from the second end into the interior of the cover body 32. The boss 31 is provided on the bottom wall of the fourth receiving portion 331. The boss 31 extends from the bottom wall of the fourth receiving portion 331 in a direction away from the cover body 32.

[0181] The opening area of ​​the fourth receiving portion 331 is larger than the cross-sectional area of ​​the boss 31. The opening area of ​​the fourth receiving portion 331 is also larger than the cross-sectional area of ​​the thrust plate 23 of the seal 2, so as to accommodate the thrust plate 23 in the fourth receiving portion 331. By providing the fourth receiving portion 331, space can be reserved for the thrust plate 23.

[0182] Along the axial direction of the second hole 21, the height of the fourth receiving part 331 is less than or equal to the height of the thrust plate 23. This structure allows the thrust plate 23 to be squeezed during the assembly of the seal 2 and the cover 3, thereby improving the sealing effect.

[0183] In the first embodiment, the boss 31 is cylindrical in shape, and is a cylinder of uniform diameter. The end of the boss 31 away from the main body 32 of the cover is provided with a rounded chamfer to prevent the boss 31 from bumping into the second hole 21 and generating particles.

[0184] like Figure 4 As shown, the sealing post 22 is inserted into the first hole 11, and the length of the sealing post 22 is greater than the length of the first hole 11. A portion of the sealing post 22 extends into the side of the end cover 1 near the interior of the battery cell 600. The end face of the thrust plate 23 near the sealing post 22 contacts the end face of the end cover 1 away from the interior of the battery cell 600. The boss 31 is inserted into the second hole 21, and the thrust plate 23 is accommodated in the fourth receiving portion 331.

[0185] like Figures 10-11 The diagram shown is a structural schematic of the second embodiment.

[0186] In the second embodiment, as Figure 11 As shown, the seal 2 has a second hole 21, and the seal 2 includes a sealing post 22 and a thrust plate 23 connected to the sealing post 22. The sealing post 22 and the thrust plate 23 can be two independent parts connected to each other; the sealing post 22 and the thrust plate 23 can also be an integrally formed structure.

[0187] The second hole 21 extends from the end of the thrust plate 23 away from the sealing post 22 toward the sealing post 22. The second hole 21 penetrates the thrust plate 23 and extends to the sealing post 22. The second hole 21 is a blind hole.

[0188] The second hole 21 has a chamfer 211 at the end of the thrust plate 23 away from the sealing post 22. The chamfer 211 guides the boss 31 inserted into the second hole 21, improving assembly efficiency. The chamfer 211 is arc-shaped, and its opening area gradually increases in the direction away from the sealing post 22 to facilitate the smooth insertion of the boss 31. In addition to the chamfer 211, the second hole 21 includes a cylindrical section of equal diameter and a reduced-diameter section, with the reduced-diameter section located at the end of the cylindrical section away from the chamfer 211.

[0189] In the second embodiment, the length of the second hole 21 accounts for more than 90% of the overall length of the seal 2. A thin wall 2221 is formed between the bottom wall of the second hole 21 and the bottom wall of the sealing post 22. This structure allows the operator to more easily pierce the seal 2 with a needle-shaped piece, so that the air pressure inside the battery cell 600 can be released by piercing the small hole formed by the thin wall 2221 before disassembling the seal 2, preventing the operator from being impacted by excessive internal air pressure when directly disassembling the seal 2.

[0190] The sealing column 22 includes a sealing body portion 221 and a conical portion 222 connected to the sealing body portion 221. The sealing body portion 221 and the conical portion 222 can be two relatively independent parts connected to each other, or they can be integrally formed. The cross-sectional area of ​​the conical portion 222 gradually decreases in the direction away from the thrust plate 23. The end of the conical portion 222 away from the thrust plate 23 is a plane.

[0191] By setting the cone 222, the sealing post 22 can be guided when it is inserted into the first hole 11, which facilitates the insertion of the sealing post 22 and improves assembly efficiency.

[0192] The sealing post 22 is also provided with a weight-reducing recess 223, which can be provided on the sealing body 221. The weight-reducing recess 223 extends from the outer surface of the sealing body 221 in a direction close to the central axis of the sealing body 221. Multiple weight-reducing recesses 223 can be provided in the circumferential direction of the sealing post 22 to reduce the overall weight of the sealing element 2.

[0193] The thrust plate 23 is also cylindrical, and its height is less than that of the sealing column 22.

[0194] like Figure 10 As shown, the structure of the cover 3 and the way the cover 3 and the seal 2 are matched are the same as the structure of the cover 3 in the first embodiment, and will not be described again.

[0195] like Figures 12-14 The diagram shown is a structural schematic of the third embodiment.

[0196] like Figure 13 As shown, the seal 2 has a second hole 21, and the seal 2 includes a sealing post 22 and a thrust plate 23 connected to the sealing post 22. The sealing post 22 and the thrust plate 23 can be two independent parts connected to each other; the sealing post 22 and the thrust plate 23 can also be an integrally formed structure.

[0197] The second hole 21 extends from the end of the thrust plate 23 away from the sealing post 22 toward the sealing post 22. The second hole 21 penetrates the thrust plate 23 and extends to the sealing post 22. The second hole 21 is a blind hole.

[0198] The second hole 21 has a chamfer 211 at the end of the thrust plate 23 away from the sealing post 22. By setting the chamfer 211, the boss 31 inserted into the second hole 21 can be guided, improving assembly efficiency. The chamfer 211 is arc-shaped, and the opening area of ​​the chamfer 211 gradually increases in the direction away from the sealing post 22, so that the boss 31 can be inserted smoothly.

[0199] The second hole 21 includes a first receiving portion 212, a second receiving portion 213, a first extension portion 214, and a second extension portion 215 connected sequentially from the chamfer 211. In the direction perpendicular to the axis of the second hole 21, the cross-sectional area of ​​the first receiving portion 212 gradually increases in the direction away from the chamfer 211, the cross-sectional area of ​​the second receiving portion 213 first increases and then decreases in the direction away from the chamfer 211, the first extension portion 214 is a cylindrical hole segment of equal diameter, and the cross-sectional area of ​​the second extension portion 215 gradually decreases in the direction away from the chamfer 211.

[0200] By providing the first extension 214 and the second extension 215, the length of the second hole 21 accounts for more than 90% of the overall length of the seal 2. A thin wall 2221 is formed between the bottom wall of the second hole 21 and the bottom wall of the sealing post 22. This structure allows the operator to more easily pierce the seal 2 with a needle-shaped piece, so that before disassembling the seal 2, the internal air pressure of the battery cell 600 can be released by piercing the small hole formed by the thin wall 2221, preventing the internal air pressure from being too high and causing an impact on the operator.

[0201] In the third embodiment, the length of the second hole 21 accounts for more than 90% of the overall length of the seal 2. A thin wall 2221 is formed between the bottom wall of the second hole 21 and the bottom wall of the sealing post 22. This structure allows the operator to more easily pierce the seal 2 with a needle-shaped piece, so that the air pressure inside the battery cell 600 can be released by piercing the small hole formed by the thin wall 2221 before disassembling the seal 2, preventing the internal air pressure from being too high and causing an impact on the operator.

[0202] The sealing column 22 includes a sealing body portion 221 and a conical portion 222 connected to the sealing body portion 221. The sealing body portion 221 and the conical portion 222 can be two relatively independent parts connected to each other, or they can be integrally formed. The cross-sectional area of ​​the conical portion 222 gradually decreases in the direction away from the thrust plate 23. The end of the conical portion 222 away from the thrust plate 23 is a plane.

[0203] By setting the cone 222, the sealing post 22 can be guided when it is inserted into the first hole 11, which facilitates the insertion of the sealing post 22 and improves assembly efficiency.

[0204] The sealing post 22 is also provided with a weight-reducing recess 223, which can be provided on the sealing body 221. The weight-reducing recess 223 extends from the outer surface of the sealing body 221 in a direction close to the central axis of the sealing body 221. Multiple weight-reducing recesses 223 can be provided in the circumferential direction of the sealing post 22 to reduce the overall weight of the sealing element 2.

[0205] The thrust plate 23 is also cylindrical, and its height is less than that of the sealing column 22.

[0206] like Figure 14 As shown, the cover 3 has a boss 31, and the cover 3 includes a cover body 32 and a limiting part 33 connected to the cover body 32. The limiting part 33 and the cover body 32 can be two relatively independent parts connected to each other, or they can be integrally formed. In the third embodiment, two limiting parts 33 are connected to the outer periphery of the cover body 32.

[0207] The first end of the cover body 32 is provided with a third groove 321 extending from the end face of the first end toward the interior of the cover body 32. For example, the cross-sectional shape of the third groove 321 is hexagonal, which facilitates the rotation of the cover 32 using tools. The side of the limiting part 33 near the first end of the cover body 32 is provided with a third receiving part 332 extending from that side face toward the interior of the limiting part 33. For example, the cross-sectional shape of the third receiving part is elliptical.

[0208] A boss 31 is provided at the second end of the cover body 32 opposite to the first end. The second end of the cover body 32 is provided with a fourth receiving portion 331 extending from the second end into the interior of the cover body 32. The boss 31 is provided on the bottom wall of the fourth receiving portion 331. The boss 31 extends from the bottom wall of the fourth receiving portion 331 in a direction away from the cover body 32.

[0209] The opening area of ​​the fourth receiving portion 331 is larger than the cross-sectional area of ​​the boss 31. The opening area of ​​the fourth receiving portion 331 is also larger than the cross-sectional area of ​​the thrust plate 23 of the seal 2, so as to accommodate the thrust plate 23 in the fourth receiving portion 331. By providing the fourth receiving portion 331, space can be reserved for the thrust plate 23.

[0210] Along the axial direction of the second hole 21, the height of the fourth receiving part 331 is less than or equal to the height of the thrust plate 23. This structure allows the thrust plate 23 to be squeezed during the assembly of the seal 2 and the cover 3, thereby improving the sealing effect.

[0211] In the third embodiment, the boss 31 includes a first insertion part 311. In the axial direction perpendicular to the second hole 21, the cross-sectional area of ​​the first insertion part 311 gradually increases in the direction away from the main body part 32 of the cover. The cross-sectional shape of the first insertion part 311 along the axial direction of the second hole 21 is trapezoidal.

[0212] The end of the first insertion part 311 away from the main body part 32 of the cover is provided with a rounded chamfer to prevent the boss 31 from bumping and generating particles when it is inserted into the second hole 21.

[0213] like Figure 12 As shown, the first insertion part 311 is inserted into the first receiving part 212 of the second hole 21, while no solid structure is inserted into the first extension part 214 and the second extension part 215. The thrust plate 23 is received in the fourth receiving part 331. This structure, through the cooperation of the first insertion part 311 and the first receiving part 212, can effectively prevent the seal 2 from separating from the cover 3.

[0214] like Figures 15-18 The diagram shown is a structural schematic of the fourth embodiment.

[0215] like Figure 16 As shown, the seal 2 has a second hole 21, and the seal 2 includes a sealing post 22 and a thrust plate 23 connected to the sealing post 22. The sealing post 22 and the thrust plate 23 can be two independent parts connected to each other; the sealing post 22 and the thrust plate 23 can also be an integrally formed structure.

[0216] The second hole 21 extends from the end of the thrust plate 23 away from the sealing post 22 toward the sealing post 22. The second hole 21 penetrates the thrust plate 23 and extends to the sealing post 22. The second hole 21 is a blind hole.

[0217] The second hole 21 has a chamfer 211 at the end of the thrust plate 23 away from the sealing post 22. By setting the chamfer 211, the boss 31 inserted into the second hole 21 can be guided, improving assembly efficiency. The chamfer 211 is arc-shaped, and the opening area of ​​the chamfer 211 gradually increases in the direction away from the sealing post 22, so that the boss 31 can be inserted smoothly.

[0218] The second hole 21 includes a third extension 216, a first receiving portion 212, a first extension 214, and a second extension 215 connected sequentially from the chamfer 211. In the direction perpendicular to the axis of the second hole 21, the third extension 216 is a cylindrical hole segment of equal diameter, and the first receiving portion 212 is also a cylindrical hole segment of equal diameter, but the diameter of the first receiving portion 212 is larger than the diameter of the third extension 216. The first extension 214 is a cylindrical hole segment of equal diameter, and the diameter of the first extension 214 is equal to that of the third extension 216. The cross-sectional area of ​​the second extension 215 gradually decreases in the direction away from the chamfer 211.

[0219] By providing the first extension 214 and the second extension 215, the length of the second hole 21 accounts for more than 90% of the overall length of the seal 2. A thin wall 2221 is formed between the bottom wall of the second hole 21 and the bottom wall of the sealing post 22. This structure allows the operator to more easily pierce the seal 2 with a needle-shaped piece, so that before disassembling the seal 2, the internal air pressure of the battery cell 600 can be released by piercing the small hole formed by the thin wall 2221, preventing the internal air pressure from being too high and causing an impact on the operator.

[0220] In the fourth embodiment, the length of the second hole 21 accounts for more than 90% of the overall length of the seal 2. A thin wall 2221 is formed between the bottom wall of the second hole 21 and the bottom wall of the sealing post 22. This structure allows the operator to more easily pierce the seal 2 with a needle-shaped piece, so that the air pressure inside the battery cell 600 can be released by piercing the small hole formed by the thin wall 2221 before disassembling the seal 2, preventing the internal air pressure from being too high and causing an impact on the operator.

[0221] The sealing column 22 includes a sealing body portion 221 and a conical portion 222 connected to the sealing body portion 221. The sealing body portion 221 and the conical portion 222 can be two relatively independent parts connected to each other, or they can be integrally formed. The cross-sectional area of ​​the conical portion 222 gradually decreases in the direction away from the thrust plate 23. The end of the conical portion 222 away from the thrust plate 23 is a plane.

[0222] By setting the cone 222, the sealing post 22 can be guided when it is inserted into the first hole 11, which facilitates the insertion of the sealing post 22 and improves assembly efficiency.

[0223] The sealing post 22 is also provided with a weight-reducing recess 223, which can be provided on the sealing body 221. The weight-reducing recess 223 extends from the outer surface of the sealing body 221 in a direction close to the central axis of the sealing body 221. Multiple weight-reducing recesses 223 can be provided in the circumferential direction of the sealing post 22 to reduce the overall weight of the sealing element 2.

[0224] The thrust plate 23 is also cylindrical, and its height is less than that of the sealing column 22.

[0225] like Figure 17 and 18 As shown, the cover 3 has a boss 31, and the cover 3 includes a cover body 32 and a limiting part 33 connected to the cover body 32. The limiting part 33 and the cover body 32 can be two relatively independent parts connected to each other, or they can be integrally formed. In the fourth embodiment, two limiting parts 33 are connected to the outer periphery of the cover body 32.

[0226] The first end of the cover body 32 is provided with a third groove 321 extending from the end face of the first end toward the interior of the cover body 32. For example, the cross-sectional shape of the third groove 321 is hexagonal, which facilitates the rotation of the cover 32 using tools. The side of the limiting part 33 near the first end of the cover body 32 is provided with a third receiving part 332 extending from that side face toward the interior of the limiting part 33. For example, the cross-sectional shape of the third receiving part is elliptical.

[0227] A boss 31 is provided at the second end of the cover body 32 opposite to the first end. The second end of the cover body 32 is provided with a fourth receiving portion 331 extending from the second end into the interior of the cover body 32. The boss 31 is provided on the bottom wall of the fourth receiving portion 331. The boss 31 extends from the bottom wall of the fourth receiving portion 331 in a direction away from the cover body 32.

[0228] The opening area of ​​the fourth receiving portion 331 is larger than the cross-sectional area of ​​the boss 31. The opening area of ​​the fourth receiving portion 331 is also larger than the cross-sectional area of ​​the thrust plate 23 of the seal 2, so as to accommodate the thrust plate 23 in the fourth receiving portion 331. By providing the fourth receiving portion 331, space can be reserved for the thrust plate 23.

[0229] Along the axial direction of the second hole 21, the height of the fourth receiving part 331 is less than or equal to the height of the thrust plate 23. This structure allows the thrust plate 23 to be squeezed during the assembly of the seal 2 and the cover 3, thereby improving the sealing effect.

[0230] In the fourth embodiment, the boss 31 includes a second insertion portion 312 connected to the main body portion 32 of the cover and a first insertion portion 311 connected to the second insertion portion 312. The second insertion portion 312 is connected to the end of the first insertion portion 311 that is away from the main body portion 32 of the cover. Both the first insertion portion 311 and the second insertion portion 312 are cylindrical in shape with the same diameter, and the diameter of the first insertion portion 311 is larger than the diameter of the second insertion portion 312. The length of the first insertion portion 311 is shorter than the length of the second insertion portion 312.

[0231] The end of the first insertion part 311 away from the main body part 32 of the cover is provided with a rounded chamfer to prevent the boss 31 from bumping and generating particles when it is inserted into the second hole 21.

[0232] like Figure 15 As shown, the second insertion part 312 is inserted into the third extension part 216, the first insertion part 311 is inserted into the first receiving part 212 of the second hole 21, no solid structure is inserted into the first extension part 214 and the second extension part 215, and the thrust plate 23 is received in the fourth receiving part 331. This structure, through the cooperation of the first insertion part 311 and the first receiving part 212, can effectively prevent the seal 2 from separating from the cover 3.

[0233] like Figure 19A and 19B The diagram shown is a structural schematic of the fifth embodiment.

[0234] In the fifth embodiment, the seal 2 is provided with a second hole 21, and the seal 2 includes a sealing post 22 and a thrust plate 23 connected to the sealing post 22. In the direction perpendicular to the axis of the second hole 21, the cross-section of the sealing post 22 is elliptical, that is, the sealing post 22 is a non-rotating body. This structure can effectively prevent the sealing post 22 from rotating relative to the end cover 1 and reduce the wear of the seal 2.

[0235] Other structures on the seal 2 and the structure of the cover 3 can be referred to the first to fourth embodiments described above, and will not be repeated here.

[0236] Based on the improvements to the end cap assembly 10 in the above embodiments, this application also provides a housing assembly for the battery cell 600, such as... Figure 24 As shown, the housing assembly includes a housing 40, a seal 2, and a cover 3. The housing 40 is used to connect with the end cap 1 to form the outer shell 50 of the battery cell 600. The housing 40 is provided with a first hole 11 for injecting electrolyte. The seal 2 is used to seal the first hole 11. The cover 3 is used to cover at least part of the seal 2, and the cover 3 is rotatable relative to the end cap 1 to achieve a detachable connection between the cover 3 and the end cap 1.

[0237] One of the seal 2 and the cover 3 is provided with a second hole 21, and the other of the seal 2 and the cover 3 is provided with a boss 31. The boss 31 is used to be inserted into the second hole 21 and the boss 31 and the second hole 21 can rotate relative to each other to realize the rotatable connection between the seal 2 and the cover 3.

[0238] In some embodiments, the first hole 11 is provided on the side of the housing 40, and the seal 2 and the cover 3 are also provided on the side of the housing 40 accordingly. This structure facilitates the injection of electrolyte and provides more space for the arrangement of the electrode terminals 5 and the explosion-proof components 6 on the end cap 1.

[0239] One difference between the housing assembly and the end cap assembly 10 is that, in the housing assembly, the first hole 11 is located on the housing 40; while in the end cap assembly 10, the first hole 11 is located on the end cap 1. The structures of the seal 2 and the cover 3 in the housing assembly can be referenced from those in the end cap assembly 10, and will not be described further here.

[0240] Based on the end cap assembly 10 or housing assembly described above, this application also provides a battery cell 600.

[0241] In some embodiments, the battery cell 600 provided in this application includes an electrode assembly 30 and a housing 50 for accommodating the electrode assembly 30. The housing 50 includes a shell 40 and an end cap assembly 10. The end of the shell 40 has an opening 41, and the end cap assembly 10 covers the opening 41 at the end of the shell 40.

[0242] In other embodiments, the battery cell 600 provided in this application includes an electrode assembly 30 and a housing 50 for accommodating the electrode assembly 30. The housing 50 includes an end cap 1 and a housing assembly. The end of the housing 40 has an opening 41, and the end cap 1 covers the opening 41 at the end of the housing 40.

[0243] In the battery cell 600 provided in this application, the seal 2 and the cover 3 are rotatably connected, allowing the seal 2 and the cover 3 to be assembled or disassembled as a whole, which greatly simplifies the operation steps, shortens the operation time, and improves the operation efficiency.

[0244] like Figure 25 As shown, this application also provides a method for injecting electrolyte into a battery cell 600, comprising: Step S101: Inject electrolyte through the first hole 11 on the casing 50 of the battery cell 600; Step S102: The sealing element 2 and the cover 3, still connected, are removed to the first hole 11. While the sealing element 2 and the cover 3 remain connected, the first hole 11 is sealed by the sealing element 2, and at least part of the sealing element 2 is covered by the cover 3. Step S103: Rotate the cover 3 relative to the seal 2 to achieve relative fixation between the cover 3 and the outer shell 50.

[0245] When assembling the seal 2 and the cover 3, the seal 2 and the cover 3, which are in a connected state, are taken together to the first hole 11. Compared with the operation steps of taking the seal 2 first and then the cover 3, the time can be greatly saved. At the same time, the seal 2 and the cover 3 can be pre-assembled together, and the time to assemble the seal 2 and the cover 3 together can be saved when sealing after liquid injection, thereby improving the assembly efficiency.

[0246] In some embodiments, the injection method further includes: Remove the cover 3 and seal 2, which are still connected, from the housing 50.

[0247] When disassembling the cover 3 and the seal 2, they are removed as a whole. Compared with disassembling them one by one, this can significantly simplify the operation steps and improve the operation efficiency.

[0248] In some embodiments, the seal 2 is provided with a second hole 21, and the cover 3 is provided with a boss 31, which is inserted into the second hole 21. The second hole 21 is a blind hole. Before injecting electrolyte through the first hole 11 on the outer casing 50 of the battery cell 600, the electrolyte injection method further includes: The bottom wall of the second hole 21 is pierced, allowing the second hole 21 to connect the interior of the battery cell 600 with the external environment, thereby releasing the pressure inside the battery cell 600; and Remove the cover 3 and the seal 2 from the housing 50.

[0249] In this embodiment, by piercing the bottom wall of the second hole 21, the air pressure inside the battery cell 600 can be released before removing the cover 3 and the seal 2 from the outer casing 50 to open the first hole 11. This prevents the operator from being impacted or injured by excessive air pressure, and also avoids the electrolyte from being lost due to being flushed out of the battery cell 600 under air pressure.

[0250] In some embodiments, the injection method further includes: Rotate the cover 3 from the first position to the second position so that the limiting portion 33 of the cover 3 is misaligned with the second receiving portion 12 on the side of the outer casing 50 away from the interior of the battery cell 600 along the circumferential direction of the first hole 11; and Rotate the cover 3 from the second position to the first position, so that the limiting part 33 enters the second receiving part 12 to restrict the cover 3 and the seal 2 from the outer shell 50.

[0251] In this embodiment, the cover 3 and the end cap 1 are detachably connected by rotation, which is convenient to operate. With the cover 3 and end cap 1 connected or disassembled by rotation, the cover 3 and the sealing element 2 are rotatably connected. This allows the cover 3 to rotate relative to the end cap 1 while simultaneously rotating relative to the sealing element 2. This helps maintain the relative fixation of the sealing element 2 and the end cap 1, reduces wear between them, and ensures the sealing effect of the sealing element 2.

[0252] In some embodiments, the injection method further includes: Rotating the cover 3 from the first position to the second position causes the limiting part and the second receiving part 12 to be misaligned circumferentially along the first hole 11; and Remove the cover 3 and seal 2, which are still connected, from the housing 50.

[0253] like Figure 26 As shown, this application also provides a liquid injection device 700 for a battery cell 600, comprising: The electrolyte injection mechanism 701 is used to inject electrolyte into the housing 50 through the first hole 11 provided on the housing 50; and The disassembly and assembly mechanism 702 is used to remove the seal 2 and the cover 3, which are in a connected state, to the first hole 11 before sealing the first hole 11 by the seal 2, and to seal the first hole 11 by the seal 2 while the seal 2 and the cover 3 are in a connected state, to cover at least part of the seal 2 by the cover 3, and to drive the cover 3 to rotate relative to the seal 2 after the seal 2 and the first hole 11 are engaged, so as to achieve relative fixation of the cover 3 and the outer shell 50.

[0254] In this embodiment, the seal 2 and the cover 3 are always connected. The seal 2 and the cover 3 can be quickly disassembled and installed by the disassembly and assembly mechanism 702, which is highly efficient.

[0255] The features of the above-mentioned protected subjects and embodiments of this application can be referenced from each other. Where the structure allows, those skilled in the art can also flexibly combine the technical features of different embodiments to form more embodiments.

[0256] The battery end cap assembly, battery, and power supply device provided in this application have been described in detail above. Specific embodiments have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. An end cap assembly (10) for a battery cell (600), comprising: End cap (1) is provided with a first hole (11) for injecting electrolyte. Seal (2) for sealing the first hole (11); and A cover (3) for covering at least a portion of the seal (2), and the cover (3) is rotatable relative to the end cap (1) to achieve a detachable connection between the cover (3) and the end cap (1); One of the sealing element (2) and the cover (3) is provided with a second hole (21), and the other of the sealing element (2) and the cover (3) is provided with a boss (31). The boss (31) is used to be inserted into the second hole (21), and the boss (31) and the second hole (21) can rotate relative to each other, so as to realize the rotatable connection between the sealing element (2) and the cover (3). The sealing element (2) includes a sealing post (22) inserted into the first hole (11). The sealing post (22) is interference-fitted with the first hole (11), and the boss (31) is interference-fitted with the second hole (21); the coefficient of friction of the contact surface between the sealing post (22) and the first hole (11) is greater than the coefficient of friction of the contact surface between the boss (31) and the second hole (21); The end cap (1) is provided with a second receiving portion (12) arranged circumferentially along the first hole (11). The second receiving portion (12) is used to receive at least part of the cover body (3) to limit the cover body (3). The second receiving portion (12) is located on the side of the end cap (1) away from the interior of the battery cell (600). The cover (3) includes a limiting part (33). When the cover (3) is rotated to the first position, the limiting part (33) is located in the second receiving part (12) to restrict the separation of the cover (3) from the end cap (1). When the cover (3) is rotated to the second position, the limiting part (33) and the second receiving part (12) are misaligned along the circumferential direction of the first hole (11) to achieve the separation of the cover (3) from the end cap (1).

2. The end cap assembly (10) according to claim 1, wherein, The boss (31) is interference-fitted with the second hole (21) to achieve the connection between the two.

3. The end cap assembly (10) according to claim 1 or 2, wherein, The boss (31) includes a first insertion part (311), and a first receiving part (212) is provided on the wall of the second hole (21). The first insertion part (311) is received in the first receiving part (212) to restrict the seal (2) and the cover (3) from detaching.

4. The end cap assembly (10) according to claim 3, wherein, In a direction perpendicular to the axis of the second hole (21), the cross-sectional area of ​​the first receiving portion (212) gradually increases in the direction away from the inserted end of the second hole (21), and the first insert portion (311) cooperates with the first receiving portion (212) to restrict the seal (2) and the cover (3) from disengaging.

5. The end cap assembly (10) according to claim 2, wherein, The second hole (21) is a blind hole.

6. The end cap assembly (10) according to claim 1, wherein, The seal (2) and the end cap (1) are fixed relative to each other in the circumferential direction of the first hole (11).

7. The end cap assembly (10) according to claim 1, wherein, The axis of rotation of the cover (3) relative to the seal (2) is collinear with the axis of the first hole (11).

8. The end cap assembly (10) according to claim 1, wherein, The sealing element (2) also includes a thrust plate (23) connected to the sealing post (22). The thrust plate (23) is located between the cover (3) and the end cap (1). The thrust plate (23) is engaged with the end face of the first hole (11).

9. The end cap assembly (10) according to claim 1, wherein, The boss (31) is a rotating body.

10. The end cap assembly (10) according to claim 1, wherein, The boss (31) and the second hole (21) are designed to be rotatable relative to each other at least during the process of the cover (3) rotating from the first position to the second position.

11. The end cap assembly (10) according to claim 1, wherein, The end cap (1) further includes a guide portion (13) which communicates with the second receiving portion (12), and the limiting portion (33) is used to enter the second receiving portion (12) through the guide portion (13) or to separate from the end cap (1) through the guide portion (13).

12. The end cap assembly (10) according to claim 1, wherein, The end cap (1) includes an end cap body (1A) and a mounting component (4). The mounting component (4) is disposed on the surface of the end cap body (1A) and surrounds the first hole (11). The second receiving portion (12) is disposed on the mounting component (4) or the second receiving portion (12) is formed by the mounting component (4) and the end cap body (1A).

13. The end cap assembly (10) according to claim 12, wherein, The sealing element (2) includes a sealing post (22) inserted into the first hole (11). The end of the sealing post (22) near the inside of the battery cell (600) is provided with a guide slope. The length of the guide slope along the axial direction of the first hole (11) is greater than the length of the mounting component (4) along the axial direction of the first hole (11).

14. A single battery cell (600), comprising: Electrode assembly (30) and housing (50) for housing the electrode assembly (30), the housing (50) including a shell (40) and an end cap assembly (10) as claimed in any one of claims 1-13, the end of the shell (40) having an opening (41) at its end, the end cap assembly (10) covering the opening (41) at the end of the shell (40).

15. A battery (400) comprising a plurality of battery cells (600) as described in claim 14.

16. An electrical device comprising a battery cell (600) as claimed in claim 14, wherein the battery cell (600) is used to provide electrical energy.

17. A method for injecting electrolyte into a battery cell (600) as described in claim 14, comprising: Electrolyte is injected through the first hole (11) on the casing (50) of the battery cell (600); The seal (2) and cover (3) are removed to the first hole (11) while still connected, and the first hole (11) is sealed by the seal (2) while the seal (2) and cover (3) are still connected, and the cover (3) covers at least part of the seal (2); and The cover (3) is rotated relative to the seal (2) to achieve relative fixation of the cover (3) and the outer shell (50).

18. The injection method according to claim 17, further comprising: Remove the cover (3) and the seal (2) from the housing (50) while they are still connected.

19. The electrolyte injection method according to claim 18, wherein the second hole (21) is a blind hole, and the electrolyte injection method further comprises, prior to injecting electrolyte through the first hole (11) on the casing (50) of the battery cell (600): The bottom wall of the second hole (21) is pierced, allowing the second hole (21) to connect the interior of the battery cell (600) with the external environment, thereby releasing the pressure inside the battery cell (600); and Remove the cover (3) and the seal (2) from the outer shell (50).

20. The injection method according to claim 17, further comprising: Rotate the cover (3) from a first position to a second position so that the limiting portion (33) of the cover (3) is circumferentially misaligned with the second receiving portion (12) of the outer casing (50) on the side away from the interior of the battery cell (600); and Rotate the cover (3) from the second position to the first position so that the limiting part (33) enters the second receiving part (12) to restrict the separation of the cover (3) and the seal (2) from the outer shell (50).

21. The injection method according to claim 20, further comprising: Rotate the cover (3) from the first position to the second position, so that the limiting part (33) and the second receiving part (12) are misaligned along the circumference of the first hole (11); and Remove the cover (3) and the seal (2) from the housing (50) while they are still connected.

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