Battery cell end caps, end cap assemblies, battery cells, batteries, and power consumption devices

Abstract

The present application provides an end cap for a battery cell, an end cap assembly, a battery cell, a battery, and a power consumption device, in which the end cap for the battery cell includes a through hole and a pressure relief structure, the through hole is used for installing an electrode terminal, and a first weak part of the pressure relief structure is configured in an arc shape, and its center of curvature is located on one side away from the through hole, so that when the first weak part is torn, the pressure relief structure surrounded by the arc-shaped first weak part will bend back toward the center of curvature of the first weak part under the action of stress, thereby moving away from the electrode terminal, thereby reducing the risk of contact between the pressure relief structure surrounded by the first weak part and the electrode terminal, reducing the possibility of contact between the pressure relief mechanism and the electrode terminal, and being advantageous to improving the safety performance of the battery.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims priority to Chinese Patent Application No. 202220473773.1, titled "End Cap of Battery Cell, End Cap Assembly, Battery Cell, Battery and Power Consumption Device", filed on March 4, 2022, and the entire content of the above - mentioned application is incorporated herein by reference.

[0002] [Technical Field] This application relates to the technical field of electrochemical devices, and particularly to the end cap of battery cells, end cap assemblies, battery cells, batteries, and power consumption devices.

Background Art

[0003] Batteries have advantages such as high specific energy and high power density, and are widely applied to electronic devices, such as mobile phones, laptop computers, battery vehicles, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and electric tools.

[0004] In the development of battery technology, lithium - ion batteries are widely applied because they have advantages such as large energy density, high output power, long cycle life, and low environmental pollution. Currently, in addition to improving the energy density of batteries, safety performance is also an issue that cannot be ignored. If the safety problem of the battery cannot be guaranteed, this battery cannot be used. Therefore, how to improve the safety of the battery is an urgent technical problem to be solved in battery technology.

Summary of the Invention

[0005] In view of the above problems, this application provides an end cap of a battery cell, an end cap assembly, a battery cell, a battery, and a power consumption device, which are advantageous for improving the safety performance of the battery.

[0006] On the other hand, this application provides an end cap for a battery cell, including a through hole and a pressure relief structure. The through hole is used to attach the electrode terminals of the battery cell. The pressure relief structure is provided with a first weak point, which is configured in an arc shape, and the center of curvature of the first weak point is located on one side away from the through hole, and the pressure relief structure is configured to rupture along the first weak point when the internal pressure of the battery cell reaches a threshold, thereby causing at least a portion of the pressure relief structure to fold back to the side away from the through hole and release the internal pressure.

[0007] In the technical invention of the embodiment of this application, when the first weak point ruptures, the pressure-releasing structure surrounded by the arc-shaped first weak point folds back toward the center of curvature of the first weak point due to the stress action, thereby separating from the electrode terminals. This reduces the risk of the pressure-releasing structure surrounded by the first weak point coming into contact with the electrode terminals, thereby reducing the possibility of contact between the pressure-releasing mechanism and the electrode terminals, which is advantageous in improving the safety performance of the battery.

[0008] According to one embodiment of this application, the pressure relief structure is further provided with a rotating shaft portion, located on one side away from the through hole of the first weak portion, and at least a portion of the pressure relief structure can be folded around the rotating shaft portion as an axis. By providing the rotating shaft portion, the closed contour region surrounded by the rotating shaft portion and the first weak portion in the pressure relief structure can be inverted around the rotating shaft portion as an axis, making it easier for those skilled in the art to define the inversion region in the pressure relief structure and to arrange the pressure relief structure.

[0009] According to one embodiment of this application, the thickness of the first weak point is smaller than the thickness of the rest of the end cap, and the most easily ruptured part of the end cap can be made the first weak point.

[0010] According to one embodiment of this application, the thickness of the rotating shaft portion is between the thickness of the first weak portion and the thickness of the remaining portion of the pressure-relieving structure, making the strength of the rotating shaft portion less than the strength of the remaining portion of the pressure-relieving structure, and the pressure-relieving structure enclosed by a closed contour is easily inverted when reversing around the rotating shaft portion as the axis.

[0011] According to one embodiment of the present invention, the pressure relief structure is further provided with two second weak points, each of which is located at both ends of the first weak point, and both second weak points are connected between the first weak point and the rotating shaft, and the second weak points, the rotating shaft, and the first weak point are connected to form a closed contour.

[0012] By installing a second weak point, the second weak point is connected between the first weak point and the rotating shaft, enclosing a closed contour, and the second weak point, the first weak point, and the rotating shaft together form an inverted portion in the pressure relief structure.

[0013] According to one embodiment of this application, a first groove is provided on the rotating shaft portion, and the first groove is opened on one side approaching the inside of the battery cell of the pressure-discharging structure, allowing a notch to be opened for inversion of the pressure-discharging structure enclosed by a closed contour, further reducing the difficulty of inverting the pressure-discharging structure enclosed by a closed contour.

[0014] According to one embodiment of this application, a second groove is provided in the first weak portion, and the second groove is opened on one side away from the inside of the battery cell of the pressure-releasing structure, which is advantageous in making the first weak portion more prone to rupture.

[0015] According to one embodiment of this application, both the first groove and the second groove are configured as V-shaped grooves. Because the bottom of the V-shaped groove has a sharp shape, it has a downward cracking stress, and has a relatively significant effect of reducing the strength of the area in which it is located, thereby effectively reducing the strength of the rotating shaft portion and the first weak point.

[0016] According to one embodiment of this application, two through holes are provided, and the pressure relief structure is installed symmetrically with respect to the perpendicular bisector of the central connection line of the two through holes, which not only facilitates the positioning of the end cap of the pressure relief structure but also facilitates the processing and molding of the pressure relief structure.

[0017] According to one embodiment of this application, the perpendicular bisector passes through the center of the end cap, facilitating the determination of the position of the through hole and facilitating the machining and manufacturing of the through hole in the end cap.

[0018] According to one embodiment of this application, the central angle corresponding to the first weak point is 180° or less, which ensures that the first weak point is located on the same side of the two through holes, avoids the first weak point being too large or being installed across the central connection line of the two through holes for other reasons, and is advantageous in determining the placement position of the first weak point.

[0019] According to one embodiment of this application, a recess is provided in the end cap, and the pressure relief structure is installed at the bottom of the recess. The installation of the recess can reduce the thickness of the area therein, thereby making the thickness of the region where the pressure relief structure is located relatively small, making it easier to rupture, which helps to realize the exhaust pressure relief function of the pressure relief mechanism.

[0020] According to one embodiment of this application, the recess includes a recessed step arranged along the side wall of the recess. The recessed step is advantageous in improving the ease of machining the recess by avoiding the recess becoming too deep and difficult to machine.

[0021] In another embodiment, the present application provides an end cap assembly comprising an end cap and electrode terminals according to any of the above technical proposals, wherein the electrode terminals are drilled in through holes.

[0022] In another embodiment, the present application provides a battery cell comprising an end cap assembly and a case according to the above-described technical invention, wherein an opening is provided at one end of the case, and the end cap assembly covers the opening.

[0023] In another embodiment, the present application provides a battery comprising a battery cell according to the above-described invention.

[0024] In another embodiment, the present application provides a power consumption device which includes a battery according to the above-described technical invention, and the battery is used to provide electrical energy.

[0025] The technical solutions according to the embodiments of the present disclosure bring at least the following beneficial effects.

[0026] This application provides an end cap for a battery cell. The end cap of the battery cell includes a through hole and a pressure relief structure. The through hole is used for installing an electrode terminal. The first weak part of the pressure relief structure is configured in an arc shape, and the center of curvature thereof is located on one side away from the through hole. When the first weak part cracks, the pressure relief structure surrounded by the arc-shaped first weak part folds back towards the center of curvature of the first weak part under the action of stress, thereby moving away from the electrode terminal, reducing the risk of contact between the pressure relief structure surrounded by the first weak part and the electrode terminal, reducing the possibility of contact between the pressure relief mechanism and the electrode terminal, and being advantageous for improving the safety performance of the battery.

[0027] This application provides an end cap assembly. Since this end cap assembly includes the end cap according to the above technical solution, this end cap assembly can reduce the possibility of contact between the pressure relief mechanism and the electrode terminal, and is advantageous for improving the safety performance of the battery.

[0028] This application provides a battery cell. Since this battery cell includes the end cap assembly according to the above technical solution, this battery cell has relatively high safety.

[0029] This application provides a battery. Since this battery includes the battery cell according to the above technical solution, this battery has relatively high safety.

[0030] This application provides a power consumption device. Since this power consumption device includes the battery according to the above technical solution, this power consumption device has relatively high safety.

Brief Description of the Drawings

[0031] To more clearly illustrate the technical concept of the embodiments of this application, the following briefly introduces the drawings that may be used in the embodiments of this application. It is obvious that the drawings in the following description are only a few of the embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without expending any creative effort. [Figure 1] This is a schematic diagram of the structure of a vehicle according to several embodiments of this application. [Figure 2] This is an exploded view of a battery according to some embodiments of this application. [Figure 3] This is a schematic diagram of the disassembled structure of a battery cell according to some embodiments of this application. [Figure 4] This is a schematic diagram of the structure of an end cap from a first viewpoint according to several embodiments of this application. [Figure 5] This is a schematic diagram of the structure of an end cap from a second perspective, according to some embodiments of this application. [Figure 6] This is a cross-sectional view of an end cap according to several embodiments of this application. [Figure 7] This is a magnified view of area A in Figure 6. [Modes for carrying out the invention]

[0032] The embodiments of this application will be described in more detail below, linking them with the drawings and examples. The detailed descriptions of the embodiments and drawings below are for illustrative purposes to illustrate the principles of this application, but are not intended to limit the scope of this application; in other words, this application is not limited to the embodiments described.

[0033] In the description of this application, unless otherwise specified, the meaning of "multiple" is two or more. The directions or positional relationships indicated by terms such as "up," "down," "left," "right," "inside," and "outside" are merely for the convenience and simplification of the description in this application and do not indicate or imply that the mentioned devices or elements have a specific direction or must be configured and operated in a specific direction, and should not be understood as limitations on this application. Furthermore, terms such as "first," "second," and "third" are used solely for descriptive purposes and should not be understood as indicating or implying relative importance. "Perpendicular" does not mean perpendicular in the strict sense, but is within the tolerance range. "Parallel" does not mean parallel in the strict sense, but is within the tolerance range.

[0034] The “Examples” as used in this application mean that certain features, structures, or characteristics described in conjunction with the Examples may be included in at least one Example of this application. The appearance of this phrase in each location in the specification does not necessarily refer to the same Example, nor does it mean that each Example is mutually exclusive or alternative to the others. Those skilled in the art will understand, both explicitly and implicitly, that the Examples described in this application may be combined with other Examples.

[0035] The directional terms used in the following description all refer to the directions illustrated and do not limit the specific structure of this application. Furthermore, unless explicitly defined or limited, the terms “attachment,” “connection,” and “connection” in this application should be understood in a broad sense, and may refer to, for example, a fixed connection, a removable connection, or an integral connection; a direct connection or an indirect connection via an intermediate medium. Those skilled in the art will be able to understand the specific meaning of these terms in this application depending on the specific circumstances.

[0036] Currently, market development trends indicate that the applications of batteries are becoming increasingly diverse. Batteries are not only used in energy storage and power systems such as hydroelectric, thermal, wind, and solar power plants, but also in electric transportation such as electric bicycles, electric motorcycles, and electric vehicles, as well as in multiple fields such as military equipment and aerospace. Along with the continuous expansion of battery application fields, the market demand is also constantly growing.

[0037] In related technologies, a pressure release mechanism is generally installed in the end cap of a battery cell. This mechanism opens when the internal pressure of the battery cell reaches a threshold, releasing pressure from the inside of the battery cell and ensuring that the internal pressure remains within a preset range, thereby guaranteeing the safety of the battery cell. Generally, the pressure release mechanism is formed by creating a groove in the end cap, thereby creating a vulnerable area in the end cap. When the internal pressure of the battery cell reaches a threshold, the groove cracks, a portion of the end cap folds back, and the pressure release mechanism is activated. Such a pressure release mechanism can keep the internal pressure of the battery cell within a preset range, preventing the internal pressure from becoming too high, reducing the risk of the battery cell exploding, and improving the safety of the battery cell.

[0038] The applicant noticed that in a pressure relief structure installed in a battery cell by creating grooves, when the pressure relief mechanism is activated, some end caps fold back in a direction that approaches the electrode terminals, causing the end caps to come into contact with the electrode terminals and creating a risk of short-circuiting the battery cell, which is detrimental to improving the safety of the battery cell.

[0039] To avoid short circuits in battery cells, the applicant discovered through research that by setting the shape of the formed weak point, the end cap that cleaves along the weak point does not come into contact with the electrode terminals, thereby preventing short circuits in battery cells. Specifically, the weak point, which is configured as a pressure-releasing structure, is set in an arc shape, and the center of curvature of the arc is located on one side away from the electrode terminals of the first weak point. As a result, when the weak point cleaves, the inverted end cap is folded back to the side away from the electrode terminals by the force of the stress.

[0040] Based on the above considerations, the applicant, after diligent research, has designed an end cap for the battery cell to avoid short circuits in the battery cell. By placing a vulnerable portion in this end cap where the center of curvature is away from the electrode terminals, the inverted end cap is folded back in a direction away from the electrode terminals, thereby preventing the inverted end cap from coming into contact with the electrode terminals, thus avoiding the risk of the end cap short-circuiting the battery cell and improving the safety of the battery cell.

[0041] The end cap for a battery cell disclosed in the embodiments of this application is used at the end of the battery cell, and a pressure-releasing structure and electrode terminals are installed on it so that the end cap can release pressure from the inside of the battery cell and further draw current out to the outside via the electrode terminals and output it to the outside. The end cap disclosed in the embodiments of this application can be used in, but is not limited to, a rechargeable battery cell, which is a battery that can be used again after the battery cell has been discharged by activating the active material through a charging method, and the end cap disclosed in the embodiments of this application can effectively prevent short circuits in the battery cell itself, which is advantageous in improving the safety of the battery cell.

[0042] The embodiments of this application provide a battery cell that can be used in power-consuming devices such as vehicles, ships, or aircraft, but are not limited to these applications. The battery cell, battery, etc. disclosed in this application can constitute a power supply system for such power-consuming devices, which is advantageous in improving the stability of battery performance and battery life.

[0043] Embodiments of this application provide a power consumption device that uses a battery as a power source, and the power consumption device may be a vehicle, mobile phone, portable device, laptop computer, steamship, aerospace vehicle, electric toy, and power tool. A vehicle may be a fuel oil vehicle, a gas vehicle, or a new energy vehicle, and a new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or a range extender vehicle, etc. Aerospace vehicles include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric steamship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, polishing power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, hammer drills, concrete vibrators, and electric planers, etc. Embodiments of this application do not particularly limit the power consumption device.

[0044] For the sake of explanation, the following embodiments will be described using the example that the power consumption device in one embodiment of this application is a vehicle 1000.

[0045] Referring to Figure 1, which is a schematic diagram of the structure of a vehicle 1000 according to some embodiments of the present application, the vehicle 1000 may be a fuel oil vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or a range extender vehicle. A battery 100 is installed inside the vehicle 1000, and the battery 100 may be installed at the bottom, head, or tail of the vehicle 1000. The battery 100 may be used to supply power to the vehicle 1000, for example, the battery 100 may be used as the operating power source for the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300, the controller 200 being used to control the battery 100 to supply power to the motor 300, for example, to meet the operating power consumption requirements for starting the vehicle 1000, navigation, and driving.

[0046] In some embodiments of this application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but can also serve as a driving power source for the vehicle 1000, providing driving power to the vehicle 1000 in place of or in place of fuel oil or natural gas.

[0047] Referring to Figure 2, which is an exploded view of a battery 100 according to some embodiments of the present application, the battery 100 includes a housing 10 and battery cells 20 housed within the housing 10. Here, the housing 10 is used to provide a housing space for the battery cells 20, and the housing 10 may employ various structures. In some embodiments, the housing 10 may include a first portion 11 and a second portion 12, the first portion 11 and the second portion 12 overlapping each other, and the first portion 11 and the second portion 12 jointly define a housing space for housing the battery cells 20. The second portion 12 is a hollow structure with one end open, and the first portion 11 may be a plate-like structure, with the first portion 11 overlapping the open side of the second portion 12 so that the first portion 11 together with the second portion 12 defines a housing space, and both the first portion 11 and the second portion 12 may be hollow structures with one end open, with the open side of the first portion 11 overlapping the open side of the second portion 12. Of course, the housing 10 formed by the first part 11 and the second part 12 may have various shapes, such as a cylinder or a rectangular prism.

[0048] In the battery 100, there may be multiple battery cells 20, and the connections between the multiple battery cells 20 may be in series, in parallel, or in series-parallel. Series-parallel connection means that the multiple battery cells 20 may be connected in series or in parallel. The multiple battery cells 20 may be directly connected in series, in parallel, or in series-parallel, and the entire assembly of the multiple battery cells 20 may be housed in the housing 10. Of course, the battery 100 may first be configured as a battery module by connecting the multiple battery cells 20 in series, in parallel, or in series-parallel, and then the multiple battery modules may be connected in series, in parallel, or in series-parallel to form an integrated unit, which may then be housed in the housing 10. The battery 100 may further include other structures; for example, the battery 100 may further include busbar members for realizing electrical connections between the multiple battery cells 20.

[0049] Here, each battery cell 20 may be a secondary battery or a primary battery, and may be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 20 may have a cylindrical, flattened, rectangular parallelepiped, or other shape.

[0050] Referring to Figure 3, Figure 3 is a schematic diagram of the exploded structure of a battery cell 20 according to some embodiments of this application. A battery cell 20 is the smallest unit that constitutes a battery. As shown in Figure 3, the battery cell 20 includes an end cap 21, a case 22, a battery core assembly 23, and other functional members.

[0051] The end cap 21 refers to a component that is placed over the opening of the case 22 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap 21 is not limited to that of the case 22 and may conform to the shape of the case 22. Selectively, the end cap 21 may be made of a material having a certain hardness and strength (e.g., an aluminum alloy), so that the end cap 21 is less likely to deform when pushed out and impacted, the battery cell 20 can have higher structural strength, and safety performance can be improved. Functional components such as electrode terminals 21a may be installed on the end cap 21. The electrode terminals 21a may be used to electrically connect to the battery core assembly 23 to output or input electrical energy from the battery cell 20. In some embodiments, the end cap 21 may further be equipped with a pressure relief mechanism to release internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The material of the end cap 21 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, or plastic, and the embodiments of this application do not impose any particular limitations thereon. In some embodiments, an insulating member may be further installed inside the end cap 21, and the insulating member may be used to separate the end cap 21 from the electrical connection member in the case 22 in order to reduce the risk of short circuits. Exemplarily, the insulating member may be plastic, rubber, or the like.

[0052] The case 22 is an assembly that fits onto the end cap 21 to form the internal environment of the battery cell 20, which may be used to house the battery core assembly 23, electrolyte, and other components. The case 22 and the end cap 21 may be separate components, or an opening may be provided on the case 22, and the internal environment of the battery cell 20 is formed by covering the opening with the end cap 21. The end cap 21 and the case 22 may be integrated, and specifically, the end cap 21 and the case 22 may first form a common connection surface before other components enter the case, and then the case 22 is placed over the end cap 21 when it is necessary to package the inside of the case 22. The case 22 may have various shapes and sizes, such as a rectangular parallelepiped, cylindrical shape, or hexagonal prism shape. Specifically, the shape of the case 22 may be determined according to the specific shape and size of the battery core assembly 23. The material of case 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, or plastic, and the embodiments of this application do not impose any particular limitations thereon.

[0053] The battery core assembly 23 consists of a positive electrode plate, a negative electrode plate, and a separator. The battery cell operates primarily by the movement of metal ions between the positive and negative electrode plates. In some embodiments, the positive electrode plate includes a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer being coated on the surface of the positive electrode current collector, the positive electrode current collector without the positive electrode active material layer protruding from the positive electrode current collector with the positive electrode active material layer, and the positive electrode current collector without the positive electrode active material layer being a positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode plate includes a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer being coated on the surface of the negative electrode current collector, the negative electrode current collector including a negative electrode coating region and a negative electrode tab connected to the negative electrode coating region, the negative electrode active material layer being coated on the negative electrode coating region and not on the negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material layer includes a negative electrode active material, which may be carbon or silicon, etc. The material of the separator may be PP (polypropylene) or PE (polyethylene), etc. The battery core assembly 23 may have a wound structure or a laminated structure, and the embodiments of this application are not limited to these. The following current collectors may be applied to both positive electrode current collectors and negative electrode current collectors. The portions of the positive and negative electrode plates containing the active material constitute the main body of the battery core assembly, and the positive and negative electrode tabs may both be located at one end of the main body, or they may each be located at both ends of the main body. During charging and discharging of the battery, the positive and negative electrode active materials react with the electrolyte, and the tabs 23a are electrically connected to the electrode terminals to extract electrical energy.

[0054] According to some embodiments of the present application, Figure 4 is a schematic diagram of the structure of an end cap from a first viewpoint according to some embodiments of the present application, and Figure 5 is a schematic diagram of the structure of an end cap from a second viewpoint according to some embodiments of the present application. Some embodiments of the present application provide an end cap 21 for a battery cell, comprising a pressure relief structure 212 and a through hole 211, the through hole 211 being used to mount the electrode terminals 21a of the battery cell, the pressure relief structure 212 being provided with a first weak point 2121, the first weak point 2121 being configured in an arc shape, the center of curvature of the first weak point 2121 being located on one side away from the through hole 211, the pressure relief structure 212 being configured to rupture along the first weak point 2121 when the internal pressure of the battery cell reaches a threshold, thereby allowing at least a portion of the pressure relief structure 212 to fold back to one side away from the through hole 211 and release the internal pressure.

[0055] The through-hole 211 is a hole that penetrates the end cap 21 along the thickness direction, and the electrode terminals 21a of the battery cell are drilled in the through-hole 211, enabling the output of electrical energy from the battery cell to the outside.

[0056] The first weak point 2121 is a region in the pressure-releasing structure 212 with relatively low strength, and the strength of the first weak point 2121 is lower than the strength of the other parts on the end cap 21. When the internal pressure of the battery cell reaches a threshold, the first weak point 2121 ruptures and releases pressure. In some embodiments of this application, the first weak point 2121 can be constructed using a relatively weak material, thereby lowering the strength of the first weak point 2121 compared to the strength of the other parts on the end cap 21. Furthermore, the strength of the pressure-releasing structure 212 therein may be weakened by installing some structure such that the strength of the first weak point 2121 is lower than the strength of the other parts on the end cap 21. For example, the strength of the pressure-releasing structure 212 therein may be weakened by installing a structure that removes material from the first weak point 2121. According to the proposed technology, the first weak point 2121 has a lower strength than the other parts of the pressure release structure 212. When the internal pressure of the battery cell reaches a threshold, the end cap 21 of the battery cell ruptures at the first weak point 2121 of the pressure release mechanism, and does not rupture at other parts. This allows gas inside the battery cell to be released from the first weak point 2121, reducing the internal pressure of the battery cell and ensuring the safety of the battery cell.

[0057] "The first weak point 2121 is configured in an arc shape" means that the shape of the region forming the first weak point 2121 is arc-shaped. The first weak point 2121 may be arc-shaped, elliptical arc-shaped, or helical arc-shaped, and the specific shape of the arc shape is not limited herein. A person skilled in the art can select it according to the actual situation, and the center of curvature of the first weak point 2121 should be located on one side away from the through hole 211 of the first weak point 2121.

[0058] When the internal pressure of the battery cell reaches a threshold and the pressure relief structure 212 ruptures along the first weak point 2121, the pressure relief structure 212 surrounded by the arc-shaped first weak point 2121 folds back toward the center of curvature of the first weak point 2121 due to stress. In this process, the portion of the pressure relief structure 212 surrounded by the first weak point 2121 stays away from the electrode terminals 21a, reducing the risk of contact between the pressure relief mechanism and the electrode terminals 21a, and thus improving the safety performance of the battery 100.

[0059] In some embodiments of this application, as shown in Figures 6 and 7, the pressure relief structure 212 is further provided with a rotating shaft portion 2122, the rotating shaft portion 2122 is located on one side away from the through hole 211 of the first weak portion 2121, and at least some of the pressure relief structure 212 can be folded around the rotating shaft portion 2122 as an axis.

[0060] The rotating shaft portion 2122 refers to the transfer point between the folded pressure-relieving structure 212 and the unfolded pressure-relieving structure 212 when a portion of the pressure-relieving structure 212 is folded back, and the folded pressure-relieving structure 212 rotates around this transfer point as an axis. It should be explained that the rotating shaft portion 2122 is a region in the pressure-relieving structure where the first vulnerable portion 2121 is not installed, and when the internal pressure of the battery cell 20 reaches a threshold, the first vulnerable portion 2121 does not rupture, preventing the rotating shaft portion 2122 from rupturing, and the rotating shaft portion 2122 can serve as the pivot axis of the folded pressure-relieving structure 212.

[0061] "The rotating shaft portion 2122 is located on one side away from the through hole 211 of the first vulnerable portion 2121" means that the rotating shaft portion 2122 and the through hole 211 are located on opposite sides of the first vulnerable portion 2121. The region enclosed by the closed contour is the region of the inverted pressure relief structure 212, thereby allowing the pressure relief structure 212 to be inverted in the designated region (the region enclosed by the closed contour), facilitating the division of each region in the pressure relief structure 212. In some embodiments, the projections of the rotating shaft portion 2122 and the end cap 21 of the first vulnerable portion 2121 away from the battery core assembly 23 are connected to form a closed contour, and the pressure relief structure 212 enclosed by the closed contour can be folded around the rotating shaft portion 2122 as an axis.

[0062] By installing the rotating shaft portion 2122, the region of the pressure relief structure 212 surrounded by the rotating shaft portion 2122 and the first vulnerable portion 2121 is inverted, making it easier for a person skilled in the art to define the inverted region in the pressure relief structure 212 and to arrange the pressure relief structure 212.

[0063] In some embodiments of this application, the thickness of the first weak portion 2121 is less than the thickness of the rest of the end cap 21.

[0064] By setting the thickness of the first weak point 2121 to be smaller than the thickness of the rest of the end cap 21, the strength of the first weak point 2121 becomes lower than the strength of the rest of the end cap 21. This method ensures that the most vulnerable part of the end cap 21 is the first weak point 2121, and if the pressure relief structure 212 ruptures due to the internal pressure of the battery cell, the rupture will occur at the first weak point 2121, making it easier to set the rupture location of the pressure relief structure 212. Furthermore, forming the first weak point 2121 by weakening the structural strength by changing the thickness is easier to operate than forming the first weak point 2121 by changing the material, and is advantageous in reducing the processing cost of the first weak point 2121.

[0065] In some embodiments of the present application, the thickness of the rotating shaft portion 2122 is between the thickness of the first weak portion 2121 and the thickness of the remaining portion of the pressure relief structure 212.

[0066] That is, there is a relationship of H1 < H2 < H3 among the thickness H2 of the rotating shaft portion 2122, the thickness H1 of the first weak portion 2121, and the thickness H3 of the remaining portion of the pressure relief structure 212. By setting the thickness of the rotating shaft portion 2122 to be smaller than the thickness of the remaining portion of the pressure relief structure 212, the strength of the rotating shaft portion 2122 is made smaller than the strength of the remaining portion of the pressure relief structure 212, and the pressure relief structure 212 surrounded by the closed contour is easy to invert when inverting about the rotating shaft portion 2122. In some embodiments, further, the thickness H2 of the rotating shaft portion 2122 and the thickness H1 of the first weak portion 2121 may be set equal, i.e., H1 = H2. Since the first weak portion 2121 is installed in an arc shape and is closer to the electrode terminal 21a than the rotating shaft portion 2122, due to the action of the internal pressure of the battery cell, the pressure relief structure 212 surrounded by the closed contour still ruptures at the first weak portion 2121 and inverts about the rotating shaft portion 21 twenty-one two.

[0067] In some embodiments of the present application, as shown in FIGS. 4 and 5, two further second weak portions 2123 are provided in the pressure relief structure 212. The two second weak portions 2123 are respectively installed at both ends of the first weak portion 2121. The two second weak portions 2123 are both connected between the first weak portion 2121 and the rotating shaft portion 2122. The second weak portion 2123, the rotating shaft portion 2122, and the first weak portion 2121 are connected to form a closed contour.

[0068] The second weak portion 2123 is a region where the strength in the pressure relief structure 212 is relatively low. The strength of the second weak portion 二十-one two three is lower than the strength of other portions on the end cap 21. Specifically, the second weak portion 2123 and the first weak portion twenty-one two one use the same thickness, whereby the second weak portion 2123 and the first weak portion 2121 have the same strength, and the second weak portion 2123 can rupture simultaneously with the first weak portion 2121. [[ID=十三]]

[0069] By installing the second vulnerable portion 2123, the second vulnerable portion 2123 is connected between the first vulnerable portion 2121 and the rotating shaft portion 2122, enclosing a closed contour, and the second vulnerable portion 2123, the first vulnerable portion 2121, and the rotating shaft portion 2122 together form an inverted portion in the pressure relief structure 212.

[0070] In some embodiments of this application, as shown in Figure 7, a first groove is provided in the rotating shaft portion 2122, and the first groove is opened on one side of the pressure relief structure 212 that is close to the inside of the battery cell.

[0071] The first groove is formed on the rotating shaft portion 2122 by removing material through machining, thereby reducing the strength at this point and allowing the pressure-releasing structure 212, which is surrounded by a closed contour, to be easily reversed.

[0072] "One side approaching the inside of the battery cell" means the side of the pressure release structure 212 that approaches the battery core assembly 23 in the battery cell.

[0073] When the closed-contour pressure relief structure 212 is inverted, it inverts outward from one side approaching the inside of the battery cell, with the rotating shaft portion 2122 as the axis. The first groove is opened on the side of the pressure relief structure 212 approaching the inside of the battery cell, allowing a notch to be opened for the inversion of the closed-contour pressure relief structure 212, further reducing the difficulty of inverting the closed-contour pressure relief structure 212.

[0074] In some embodiments of this application, as shown in Figure 7, a second groove is provided in the first vulnerable portion 2121, and the second groove is opened on one side of the pressure relief structure 212 away from the inside of the battery cell.

[0075] The second groove is formed on the first weak point 2121 by removing material through machining, thereby reducing its strength and allowing the pressure-releasing structure 212, enclosed by a closed contour, to easily rupture there. In some embodiments, the second weak point 2123 is formed by installing a third groove, which is also opened on one side of the pressure-releasing structure 212 away from the inside of the battery cell and connected to the second groove, and whose structural parameters and size are the same as those of the second groove.

[0076] "One side away from the inside of the battery cell" means the side of the pressure release structure 212 in the battery cell that is away from the battery core assembly 23.

[0077] Since the internal pressure of the battery cell acts directly on one side of the pressure relief structure 212 that is close to the inside of the battery cell, the second groove is opened on one side of the pressure relief structure 212 that is away from the inside of the battery cell. This is advantageous because it makes the residual material of the first weak point 2121 more susceptible to the internal pressure of the battery cell, and thus makes the first weak point 2121 more prone to rupture.

[0078] In some embodiments of this application, as shown in Figure 7, both the first groove and the second groove are configured as V-shaped grooves.

[0079] Here, a V-shaped groove is a groove whose cross-sectional shape is V-shaped. In some embodiments, the first and second grooves may be composed of grooves of other shapes, such as U-shaped grooves, square grooves, etc. Those skilled in the art can select the shape of the groove according to the actual situation, and the groove should be able to remove material and reduce the strength of the area in which it is located.

[0080] Because the bottom of the V-shaped groove has a sharp shape, it has a downward cracking stress, which has a relatively significant effect of reducing the strength of the area where it is located, and can effectively reduce the strength of the rotating shaft portion 2122 and the first weak portion 2121.

[0081] In some embodiments of this application, as shown in Figure 4, two through holes 211 are provided, and the pressure relief structure 212 is installed symmetrically with respect to the perpendicular bisector of the central connection line of the two through holes 211.

[0082] The two through holes 211 are used to mount two electrode terminals 21a with opposite polarity, so that both electrode terminals 21a with opposite polarity of the battery cell extend from the end cap 21 to the outside of the battery cell and output electrical energy to the outside.

[0083] The "perpendicular bisector of the central connection line of the two through holes 211" refers to the perpendicular bisector of a line segment formed with the centers of the two through holes 211 as endpoints. In some embodiments, the through holes 211 are circular and can be fitted and mounted to pole posts as electrode terminals 21a. As can be understood, the through holes 211 may further be square, polygonal, or irregularly shaped, as long as they can be fitted and mounted as electrode terminals 21a, and those skilled in the art can select according to the actual situation.

[0084] By installing the pressure relief structure 212 symmetrically, not only is the positioning of the pressure relief structure 212 at the end cap 21 made easier, but the processing and molding of the pressure relief structure 212 is also made easier.

[0085] In some embodiments of this application, the perpendicular bisector passes through the center of the end cap 21.

[0086] In some embodiments, the cross-sectional shape of the end cap 21 is circular, and the center of the end cap 21 is the center of the circle. In some embodiments, the cross-sectional shape of the end cap 21 may be set to other shapes such as squares, and those skilled in the art can select according to the actual situation, as long as the end cap 21 seals and covers one end of the battery cell.

[0087] The fact that the perpendicular bisector passes through the center of the end cap 21 facilitates the determination of the position of the through hole 211 and facilitates the machining and manufacturing of the through hole 211 in the end cap 21.

[0088] In some embodiments of this application, the central angle corresponding to the first weak point 2121 is 180° or less.

[0089] The central angle corresponding to the first vulnerable area 2121 is the central angle corresponding to the sector-shaped region in which the entire first vulnerable area 2121 is located.

[0090] The central angle corresponding to the first weak point 2121 is 180° or less, which ensures that the first weak point 2121 is located on the same side of the two through holes 211, preventing the first weak point 2121 from being too large or being installed across the central connection line of the two through holes 211 for other reasons, and is advantageous in determining the placement position of the first weak point 2121.

[0091] In some embodiments of this application, as shown in Figure 5, a recess 213 is provided in the end cap 21, and the pressure relief structure 212 is installed at the bottom of the recess 213.

[0092] The recess 213 is located on one side of the end cap 21 away from the inside of the battery cell and is formed by creating a recessed area in the end cap 21. The recess 213 may be formed on the end cap 21 using a material removal method such as turning, milling, cutting, or grinding, or it may be integrally molded with the end cap 21 during the manufacturing and forming of the end cap 21 using a manufacturing method such as pressing, casting, or roll pressing, and a person skilled in the art can select the appropriate method depending on the actual situation.

[0093] The bottom of the recess 213 is the deepest plane along the thickness direction of the end cap 21 in the recess 213.

[0094] The placement of the recess 213 reduces the thickness therein, and the pressure relief structure 212 is placed at the bottom of the recess 213, thereby making the thickness of the area where the pressure relief structure 212 is located relatively small, making it easier to rupture and helping to realize the exhaust pressure relief action of the pressure relief mechanism.

[0095] In some embodiments of this application, as shown in Figure 7, the recess 213 includes a recessed step 2131 positioned along the side wall of the recess 213.

[0096] The recessed step 2131 is a step installed on the side wall of the recess 213, causing the recess 213 to be recessed in a stepped, staircase-like manner. In some embodiments, the side wall surface of the recessed step 2131 is installed at an obtuse angle to the flat surface at the bottom of the recess 213, that is, a slope is provided on the side wall of the recessed step 2131, causing the recess 213 to have an outward-facing trumpet shape, which facilitates the fabrication of the pressure relief structure 212 at the bottom of the recess 213. In some embodiments, the recessed step 2131 can be provided with one, two, or more steps, which facilitates the fabrication and molding of the recess 213.

[0097] The recessed step 2131 is advantageous in improving the ease of machining the recess 213 because it avoids the problem of the recess being too deep and difficult to machine.

[0098] In some embodiments of this application, the application further provides an end cap assembly comprising an end cap 21 and an electrode terminal 21a according to any of the above arrangements, wherein the electrode terminal 21a is drilled in a through hole 211.

[0099] Since this end cap assembly includes the end cap 21 according to the above-described technical proposal, this end cap assembly can reduce the possibility of contact between the pressure relief mechanism and the electrode terminal 21a, which is advantageous in improving the safety performance of the battery 100.

[0100] In some embodiments of this application, the application further provides a battery cell comprising an end cap assembly and a case 22 according to the above-described technical invention, wherein an opening is provided at one end of the case 22, and the end cap assembly covers the opening.

[0101] An opening at one end of the case 22 is used to incorporate the battery core assembly 23 of the battery cell into the case 22. The covering of the opening by the end cap assembly means that the end cap assembly is connected to the opening, separating the inside from the outside of the case 22. In some embodiments, the end cap assembly can be sealed to the opening to prevent leakage of material from inside the case 22.

[0102] In some embodiments of this application, the application further provides a battery 100 which includes a battery cell according to the above-described solution.

[0103] In some embodiments of this application, the application further provides a power consumption device comprising a battery 100 according to any of the above arrangements, wherein the battery 100 is used to provide electrical energy to the power consumption device.

[0104] The power consumption device may be any one of the aforementioned devices or systems that utilize batteries.

[0105] According to some embodiments of this application, as shown in Figures 4 and 5, the application provides an end cap 21 for a battery cell, comprising a pressure relief structure 212 and two through holes 211, the end cap 21 having a recess 213, as shown in Figure 7, a recessed step 2131 is provided on the side wall of the recess 213, the pressure relief structure 212 is provided on the bottom surface of the recess 213, and the pressure relief structure 212 has a first weak point 2121, two second weak points 2123 and A closed contour is provided formed by the rotating shaft portion 2122, the first vulnerable portion 2121 is configured in an arc shape, and the center of curvature of the first vulnerable portion 2121 is located on one side away from the through hole 211 of the first vulnerable portion 2121, and when the internal pressure of the battery cell reaches a threshold and the first vulnerable portion 2121 ruptures, the pressure relief structure 212 in the closed contour folds back to one side away from the through hole 211 with the rotating shaft portion 2122 as its axis, and releases the internal pressure of the battery cell. Here, the second groove in the first vulnerable portion 2121 and the third groove in the second vulnerable portion 2123 are opened on one side of the pressure relief structure 212 away from the inside of the battery cell, and the first groove in the rotating shaft portion 2122 is opened on one side of the pressure relief structure 212 approaching the inside of the battery cell. The thickness of the first weak point 2121 is less than or equal to the thickness of the rotating shaft portion 2122, so that the pressure relief structure 212 in the closed contour ruptures along the first weak point 2121 and folds back to one side away from the through hole 211 with the rotating shaft portion 2122 as the axis.

[0106] While this application has been written with reference to preferred embodiments, various improvements can be made thereto, and components thereof can be replaced with equivalents, without departing from the scope of this application. In particular, unless there is a structural conflict, each technical feature referred to in each embodiment may be combined in any manner. This application is not limited to the specific embodiments disclosed in the specification, but includes all technical ideas that fall within the scope of the claims. [Explanation of Symbols]

[0107] The reference numerals in the drawings for specific embodiments are as follows: 1000: Vehicles, 100: Battery, 200: Controller, 300: Motor 10: Enclosure, 11: First part, 12: Second part, 20: Battery cell, 21: End cap, 21a: Electrode terminal, 22: Case, 23: Battery core assembly, 23a: Tab, 211: Through hole, 212: Pressure relief structure, 2121: First weak point, 2122: Rotating shaft part, 2123: Second weak point, 213: Recess, 2131: Recessed step.

Claims

1. It is the end cap of the battery cell, Through holes for attaching the electrode terminals of the battery cell, A pressure relief structure comprising a first weak portion, the first weak portion being configured in an arc shape, the center of curvature of the first weak portion being located on one side away from the through hole, and the pressure relief structure being configured to rupture along the first weak portion when the internal pressure of the battery cell reaches a threshold, thereby causing at least a portion of the pressure relief structure to fold back to one side away from the through hole to release the internal pressure, The end cap is provided with a recess, and the pressure relief structure is installed at the bottom of the recess. The recess includes a recessed step arranged along the side wall of the recess, The pressure relief structure is further provided with a rotating shaft portion, the rotating shaft portion is located on one side away from the through hole of the first weak portion, and at least a portion of the pressure relief structure can be folded back around the rotating shaft portion as an axis. An end cap for a battery cell, wherein a first groove is provided on the rotating shaft portion, and the first groove is opened on one side of the pressure relief structure that approaches the inside of the battery cell.

2. The end cap according to claim 1, wherein the thickness of the first weak portion is less than the thickness of the rest of the end cap.

3. The end cap according to claim 1, wherein the thickness of the rotating shaft portion is between the thickness of the first weak portion and the thickness of the remaining portion of the pressure-releasing structure.

4. The end cap according to claim 1, wherein the pressure relief structure is further provided with two second vulnerable parts, the two second vulnerable parts are each located at both ends of the first vulnerable part, the two second vulnerable parts are both connected between the first vulnerable part and the rotating shaft part, and the second vulnerable parts, the rotating shaft part and the first vulnerable part are connected to form a closed contour.

5. A second groove is provided in the first vulnerable portion, and the second groove is the battery section of the pressure release structure. The end cap according to claim 1, which is opened on one side away from the inside of the tube.

6. The end cap according to claim 5, wherein both the first groove and the second groove are configured as V-shaped grooves.

7. The end cap according to claim 1, wherein two through holes are provided, and the pressure relief structure is installed symmetrically with respect to the perpendicular bisector of the central connecting line of the two through holes.

8. The end cap according to claim 7, wherein the perpendicular bisector passes through the center of the end cap.

9. The end cap according to claim 1, wherein the central angle corresponding to the first weak portion is 180° or less.

10. An end cap assembly, An end cap according to any one of claims 1 to 9, An end cap assembly including an electrode terminal drilled in the through hole.

11. It is a battery cell, The end cap assembly according to claim 10, A battery cell, comprising a case, wherein an opening is provided at one end of the case, and the end cap assembly covers the opening.

12. A battery, comprising the battery cell described in claim 11.

13. A power consumption device comprising a battery as described in claim 12, wherein the battery is used to provide electrical energy.

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