Battery cell end cap, end cap assembly, battery cell, battery and power consuming device

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, entitled "Battery Cell End Cap, End Cap Assembly, Battery Cell, Battery and Power Consumption Device," filed on March 4, 2022, the entire contents of which are incorporated herein by reference.

[0002] [Technical field] The present application relates to the technical field of electrochemical devices, and in particular to battery cell end caps, end cap assemblies, battery cells, batteries, and power consuming devices. [Background technology]

[0003] Batteries have the advantages of high specific energy and high power density, and are widely used in electronic devices, such as mobile phones, notebook computers, battery cars, electric cars, electric airplanes, electric steamships, electric toy cars, electric toy steamships, electric toy airplanes and electric tools.

[0004] In the development of battery technology, lithium ion batteries have been widely used due to their advantages of high energy density, high output power, long cycle life, and small environmental pollution. At present, in addition to improving the energy density of batteries, safety performance is also an issue that cannot be ignored. If the safety of a battery cannot be guaranteed, the battery cannot be used, so how to improve the safety of a battery is a technical issue that needs to be resolved as soon as possible in battery technology. Summary of the Invention

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

[0006] Meanwhile, the present application provides an end cap for a battery cell, including a through hole and a pressure relief structure, the through hole being used for mounting an electrode terminal of the battery cell, the pressure relief structure being provided with a first weak part, the first weak part being configured in an arc shape, the center of curvature of the first weak part being located on one side away from the through hole of the first weak part, the pressure relief structure being configured to tear along the first weak part when the internal pressure of the battery cell reaches a threshold value, so that at least a part of the pressure relief structure folds back to the one side away from the through hole to release the internal pressure.

[0007] In the technical proposals of the embodiments of the present application, when the first weak part is broken, the pressure relief structure surrounded by the arc-shaped first weak part is folded back toward 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 in improving the safety performance of the battery.

[0008] According to an embodiment of the present application, the pressure relief structure further includes a rotating shaft, which is located on one side of the rotating shaft away from the through hole of the first weak part, and at least a part of the pressure relief structure can be folded back around the rotating shaft as an axis. By installing the rotating shaft, the closed contour area surrounded by the rotating shaft and the first weak part in the pressure relief structure is inverted around the rotating shaft as an axis, which makes it easy for those skilled in the art to define the inverted area in the pressure relief structure and to arrange the pressure relief structure.

[0009] According to one embodiment of the present application, the thickness of the first weakened portion is less than the thickness of the remainder of the end cap, making the first weakened portion the most susceptible portion of the end cap.

[0010] According to one embodiment of the present 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 relief structure, making the strength of the rotating shaft portion smaller than the strength of the remaining portion of the pressure relief structure, and the pressure relief structure surrounded by a closed contour is prone to inversion when inverted around the rotating shaft portion as an axis.

[0011] According to one embodiment of the present application, the pressure relief structure further includes two second weak parts, the two second weak parts are respectively installed at both ends of the first weak part, the two second weak parts are both connected between the first weak part and the rotating shaft part, and the second weak parts, the rotating shaft part and the first weak part are connected to form a closed contour.

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

[0013] According to one embodiment of the present application, a first groove is provided on the rotating shaft portion, and the first groove is opened on one side of the pressure relief structure approaching the inside of the battery cell, and a notch can be opened for reversing the pressure relief structure surrounded by a closed contour, thereby further reducing the difficulty of reversing the pressure relief structure surrounded by a closed contour.

[0014] According to one embodiment of the present application, a second groove is provided in the first weak portion, and the second groove is opened on one side of the pressure relief structure away from the inside of the battery cell, which is advantageous for making the first weak portion more easily ruptured.

[0015] According to one embodiment of the present application, the first groove and the second groove are both configured as V-shaped grooves, and the bottom of the V-shaped groove has a sharp shape, which has a downward cracking stress, and the effect of reducing the strength of the part where it is located is relatively significant, which can effectively reduce the strength of the rotating shaft part and the first weak part.

[0016] According to one embodiment of the present application, 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, which not only facilitates the positioning of the pressure relief structure on the end cap, but also facilitates the processing and molding of the pressure relief structure.

[0017] According to one embodiment of the present application, the perpendicular bisector passes through the center of the end cap, making it easier to determine the location of the through holes and easier to fabricate in the end caps.

[0018] According to one embodiment of the present application, the central angle corresponding to the first weak portion is less than or equal to 180°, which can ensure that the first weak portion is located on the same side of the two through holes, and can avoid the first weak portion being installed across the central connecting line of the two through holes due to being too large or other reasons, which is advantageous in determining the placement position of the first weak portion.

[0019] According to one embodiment of the present application, a recess is provided in the end cap, and the pressure relief structure is installed at the bottom of the recess, and the installation of the recess can reduce the thickness of the area, and the pressure relief structure is installed at the bottom of the recess, thereby making the thickness of the area where the pressure relief structure is located relatively small and easy to rupture, which is helpful in realizing the exhaust and pressure relief function of the pressure relief mechanism.

[0020] According to one embodiment of the present application, the recess includes a recess step disposed along a sidewall of the recess, which is advantageous in preventing the recess from becoming too deep and difficult to process, and in improving the convenience of processing the recess.

[0021] According to another aspect, the present application provides an end cap assembly, which includes an end cap according to any one of the above technical solutions and an electrode terminal, the electrode terminal being drilled into the through hole.

[0022] According to another aspect, the present application provides a battery cell, which includes an end cap assembly and a case according to the above technical solution, where an opening is provided at one end of the case, and the end cap assembly is fitted over the opening.

[0023] According to another aspect, the present application provides a battery, which includes a battery cell according to the above technical solution.

[0024] According to another aspect, the present application provides a power consuming device, which includes a battery according to the above technical solution, and the battery is used to provide electrical energy.

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

[0026] The present application provides an end cap for a battery cell, the end cap for the battery cell comprising 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 open, 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, 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.

[0027] The present application provides an end cap assembly, which includes an end cap according to the above technical solution, so that the end cap assembly can reduce the possibility of contact between the pressure relief mechanism and the electrode terminal, and is advantageous in improving the safety performance of the battery.

[0028] The present application provides a battery cell, which includes an end cap assembly according to the above technical solution, so that the battery cell has a relatively high safety.

[0029] The present application provides a battery, which includes a battery cell according to the above technical solution, so that the battery has a relatively high safety.

[0030] The present application provides a power consuming device, which includes a battery according to the above technical solution, so that the power consuming device has a relatively high safety. [Brief description of the drawings]

[0031] In order to more clearly explain the technical solutions of the embodiments of the present application, the following briefly introduces drawings that need to be used in the embodiments of the present application. It is obvious that the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings based on the drawings without exerting creative efforts. [Figure 1] 1 is a structural schematic diagram of a vehicle according to some embodiments of the present application. [Diagram 2] FIG. 2 is an exploded view of a battery according to some embodiments of the present application. [Diagram 3] FIG. 2 is an exploded structural schematic diagram of a battery cell according to some embodiments of the present application. [Figure 4] 2 is a structural schematic diagram of a first view of an end cap according to some embodiments of the present application. FIG. [Diagram 5] FIG. 2 is a structural schematic diagram of a second view of an end cap according to some embodiments of the present application. [Figure 6] 1 is a cross-sectional view of an end cap according to some embodiments of the present application. [Figure 7] FIG. 7 is an enlarged view of a portion A in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] The following describes the embodiments of the present application in more detail in conjunction with the drawings and examples. The detailed description of the embodiments and the drawings are for illustrative purposes only to explain the principles of the present application, but are not intended to limit the scope of the present application, i.e., the present application is not limited to the described embodiments.

[0033] In the description of this application, it should be explained that, unless otherwise specified, the meaning of "plurality" is two or more, and the orientation or positional relationship indicated by the terms "up", "down", "left", "right", "inside", "outside", etc., is merely for convenience and simplification of the description of this application, and does not indicate or imply that the device or element referred to has a particular orientation and must be configured and operated in a particular orientation, and should not be understood as a limitation on this application. In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only, and should not be understood as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but is within a margin of error. "Parallel" is not parallel in the strict sense, but is within a margin of error.

[0034] An "embodiment" referred to in this application means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. Those skilled in the art can explicitly and implicitly understand that the embodiments described in this application can be combined with other embodiments.

[0035] The directional terms in the following description are all directions shown in the drawings, and do not limit the specific structure of the present application. In the description of the present application, it should be further explained that unless otherwise clearly specified or limited, the terms "attached", "connected" and "connected" should be understood in a broad sense, for example, as a fixed connection, a removable connection, or an integral connection, and may be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the present application according to the specific situation.

[0036] At present, from the viewpoint of market development trend, the application of batteries is becoming more and more extensive. Batteries are not only applied to energy storage power systems such as hydroelectric, thermal, wind and solar power stations, but also widely applied to electric vehicles such as electric bicycles, electric motorcycles and electric cars, as well as military equipment and aerospace. With the continuous expansion of battery application fields, the market demand is also constantly expanding.

[0037] In the related art, a pressure relief mechanism is generally installed on the end cap of the battery cell, which opens when the internal pressure of the battery cell reaches a threshold value, relieves pressure inside the battery cell, ensures that the internal pressure of the battery cell is within a preset range, and thereby ensures the safety of the battery cell. Generally, the pressure relief mechanism is formed by opening a groove in the end cap to make a weak part appear in the end cap, and when the internal pressure of the battery cell reaches a threshold value, the groove breaks and a part of the end cap is folded back, thereby realizing the pressure relief of the pressure relief mechanism. Such a pressure relief mechanism can keep the internal pressure of the battery cell within a preset range, prevent the internal pressure of the battery cell from being too high, reduce the risk of the battery cell exploding, and is advantageous to improving the safety of the battery cell.

[0038] The applicant has found that in a pressure relief structure installed on a battery cell by opening a groove, when the pressure relief mechanism is activated, some of the end caps will be folded back in a direction approaching the electrode terminal, and the end caps will abut against the electrode terminal, presenting a risk of short-circuiting the battery cell, which is detrimental to improving the safety of the battery cell.

[0039] In order to avoid short circuit of the battery cell, the applicant has found through research that the shape of the formed weak part can be set so that the end cap which is torn along the weak part does not come into contact with the electrode terminal, thereby avoiding short circuit of the battery cell. Specifically, the weak part configured in the pressure relief structure is arranged in an arc shape, and the center of curvature of the arc shape is located on one side of the first weak part away from the electrode terminal, so that when the weak part is torn, the inverted end cap is folded back to the one side away from the electrode terminal under the action of stress.

[0040] Based on the above idea, in order to prevent the battery cell from being short-circuited, the applicant has conducted extensive research and designed an end cap for the battery cell, and provided the end cap with a weak portion whose center of curvature is away from the electrode terminal, thereby folding the inverted end cap in a direction away from the electrode terminal, thereby preventing the inverted end cap from coming into contact with the electrode terminal, and thus avoiding the risk of the end cap shorting the battery cell, which is advantageous to improving the safety of the battery cell.

[0041] The end cap of the battery cell disclosed in the embodiment of the present application is used at the end of the battery cell, and a pressure relief structure and an electrode terminal are provided thereon, so that the end cap can relieve pressure inside the battery cell, and can also draw out and output current to the outside through the electrode terminal. The end cap disclosed in the embodiment of the present application can be used for, but is not limited to, a rechargeable battery cell, which is a battery that can be used continuously after the battery cell is discharged by activating the active material in a charging manner, and the end cap disclosed in the embodiment of the present application can effectively prevent the battery cell itself from being short-circuited, which is advantageous for improving the safety of the battery cell.

[0042] The embodiments of the present application provide a battery cell, which can be used in, but is not limited to, a power consuming device such as a vehicle, a ship, or an aircraft, etc. The battery cell, battery, etc. disclosed in the present application can be used to configure a power supply system for the power consuming device, thus advantageously improving the stability of battery performance and battery life.

[0043] The embodiment of the present application provides a power consumption device using a battery as a power source, and the power consumption device may be a vehicle, a mobile phone, a portable device, a notebook computer, a steamship, a spacecraft, an electric toy, an electric tool, etc. The vehicle may be a fuel oil vehicle, a gas vehicle, or a new energy vehicle, the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or a range extender vehicle, etc., the spacecraft may include an airplane, a rocket, a space shuttle, a spaceship, etc., the electric toy may include a stationary or mobile electric toy, such as a game console, an electric car toy, an electric steamship toy, an electric airplane toy, etc., and the electric tool may include a metal cutting electric tool, a polishing electric tool, an assembly electric tool, and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, a hammer drill, a concrete vibrator, an electric planer, etc. The embodiment of the present application does not particularly limit the above power consumption device.

[0044] For convenience of explanation, the following embodiment will be described by taking as an example that the power consuming device in one embodiment of the present application is a vehicle 1000.

[0045] Referring to FIG. 1, FIG. 1 is a structural schematic diagram 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, etc. 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 an operating power source for the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to supply power to the motor 300, for example, for use in starting the vehicle 1000, navigation and operating power consumption needs during driving.

[0046] In some embodiments of the present application, the battery 100 can not only serve as the operating power source for the vehicle 1000, but can also serve as the 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 FIG. 2, FIG. 2 is an exploded view of a battery 100 according to some embodiments of the present application. The battery 100 includes a housing 10 and a battery cell 20 housed in the housing 10. Here, the housing 10 is used to provide a housing space for the battery cell 20, and the housing 10 may adopt various structures. In some embodiments, the housing 10 may include a first part 11 and a second part 12, and the first part 11 and the second part 12 are covered with each other, and the first part 11 and the second part 12 jointly define a housing space for housing the battery cell 20. The second part 12 is a hollow structure with an opening at one end, and the first part 11 may be a plate-like structure, and the first part 11 is covered with the opening side of the second part 12, so that the first part 11 defines the housing space together with the second part 12, and both the first part 11 and the second part 12 may be hollow structures with an opening at one end, and the opening side of the first part 11 is covered with the opening side of the second part 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 may have various shapes, for example, a cylindrical body, a rectangular parallelepiped, etc.

[0048] In the battery 100, the battery cell 20 may be multiple, and the multiple battery cells 20 may be connected in series, parallel, or series-parallel. The 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, parallel, or series-parallel, and the entire battery cell set may be housed in the housing 10. Of course, the battery 100 may be a battery module set in which the multiple battery cells 20 are first connected in series, parallel, or series-parallel to form a battery module, and the multiple battery modules are connected in series, parallel, or series-parallel to form an integrated battery module, which is housed in the housing 10. The battery 100 may further include other structures, and for example, the battery 100 may further include a bus bar member for achieving electrical connection between the multiple battery cells 20.

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

[0050] Referring to Fig. 3, Fig. 3 is an exploded structural schematic diagram of a battery cell 20 according to some embodiments of the present application. The battery cell 20 is the smallest unit constituting a battery. As shown in Fig. 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 member that covers an 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 may be adapted to the shape of the case 22 to fit the case 22. Alternatively, the end cap 21 may be made of a material (e.g., an aluminum alloy) having a certain hardness and strength, so that the end cap 21 is less likely to be deformed when pushed out and hit, and the battery cell 20 may have higher structural strength and improved safety performance. The end cap 21 may be provided with a functional member such as an electrode terminal 21a. The electrode terminal 21a may be used to electrically connect to the battery core assembly 23 to output or input electrical energy of the battery cell 20. In some embodiments, the end cap 21 may further be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value. The material of the end cap 21 may be various, for example, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not have 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 electrical connection member in the case 22 from the end cap 21 so as to reduce the risk of short circuit. Exemplarily, the insulating member may be plastic, rubber, etc.

[0052] The case 22 is an assembly for fitting to the end cap 21 to form an internal environment of the battery cell 20, where the internal environment formed may be used to accommodate the battery core assembly 23, electrolyte, and other components. The case 22 and the end cap 21 may be independent members, or an opening may be provided on the case 22, and the end cap 21 may cover the opening at the opening to form the internal environment of the battery cell 20. Without being limited thereto, the end cap 21 and the case 22 may be integrated, specifically, the end cap 21 and the case 22 may first form a common connection surface before other components are inserted into the case, and when the inside of the case 22 needs to be packaged, the end cap 21 is further covered with the case 22. The case 22 may have various shapes and sizes, such as a rectangular parallelepiped, a cylindrical body, a hexagonal prism, etc. Specifically, the shape of the case 22 may be determined according to the specific shape and size of the battery core assembly 23. The case 22 may be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any particular limitations thereon.

[0053] The battery core assembly 23 is composed of a positive electrode plate, a negative electrode plate, and a separator. The battery cell is mainly operated by the movement of metal ions between the positive electrode plate and the negative electrode plate. In some embodiments, the positive electrode plate includes a positive electrode collector and a positive electrode active material layer, the positive electrode active material layer is coated on the surface of the positive electrode collector, the positive electrode collector without the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer, and the positive electrode collector without the positive electrode active material layer is a positive electrode tab. For example, in a lithium-ion battery, the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganate, etc. The negative electrode plate includes a negative electrode collector and a negative electrode active material layer, the negative electrode active material layer is applied to the surface of the negative electrode collector, the negative electrode collector includes a negative electrode coated area and a negative electrode tab connected to the negative electrode coated area, the negative electrode coated area is coated with the negative electrode active material layer, and the negative electrode tab is not coated with the negative electrode active material layer. The material of the negative electrode collector may be copper, the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material may be carbon or silicon, etc. The material of the separator may be PP (polypropylene) or PE (polyethylene), etc. Note that the battery core assembly 23 may have a wound structure or a stacked structure, and the embodiments of the present application are not limited thereto. The following current collectors may be applied to the positive electrode collector or the negative electrode collector. The positive and negative electrode plates having active materials constitute the body of the battery core assembly, and the positive and negative electrode tabs may be located at one end of the body or at both ends of the 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, Fig. 4 is a structural schematic diagram of a first aspect of an end cap according to some embodiments of the present application, and Fig. 5 is a structural schematic diagram of a second aspect of an end cap 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 is used for mounting an electrode terminal 21a of a battery cell, the pressure relief structure 212 is provided with a first weak part 2121, the first weak part 2121 is configured in a circular arc shape, the curvature center of the first weak part 2121 is located on one side of the first weak part 2121 away from the through hole 211, and the pressure relief structure 212 is configured to tear along the first weak part 2121 when the internal pressure of the battery cell reaches a threshold value, so that at least a part of the pressure relief structure 212 folds back to one side away from the through hole 211 to release the internal pressure.

[0055] The through-holes 211 are holes that penetrate the end cap 21 in the thickness direction, and the electrode terminals 21a of the battery cells are drilled in the through-holes 211 to enable the electrical energy of the battery cells to be output to the outside.

[0056] The first weak portion 2121 is a region of the pressure relief structure 212 with a relatively low strength, and the strength of the first weak portion 2121 is lower than the strength of other portions on the end cap 21, and when the internal pressure of the battery cell reaches a threshold, the first weak portion 2121 ruptures to relieve pressure. In some embodiments of the present application, the first weak portion 2121 can be constructed using a material with a relatively low strength, so that the strength of the first weak portion 2121 is lower than the strength of other portions on the end cap 21, and the strength of the pressure relief structure 212 here can be weakened by providing some structure, for example, a structure that removes material from the first weak portion 2121 to weaken the strength of the pressure relief structure 212 here, so that the strength of the first weak portion 2121 is lower than the strength of other portions on the end cap 21. According to the above technical solution, the first weak part 2121 makes the strength of the pressure relief structure 212 lower than the strength of other parts on the end cap 21. When the internal pressure of the battery cell reaches a threshold value, the end cap 21 of the battery cell will rupture at the first weak part 2121 of the pressure relief mechanism, rather than rupturing at other parts, so that the gas in the battery cell can be discharged through the first weak part 2121, reducing the internal pressure of the battery cell, and ensuring the safety of the battery cell.

[0057] "The first weak portion 2121 is configured in an arc shape" means that the shape of the area forming the first weak portion 2121 is arc shape, and the first weak portion 2121 may be arc shape, elliptical arc shape, or spiral arc shape, and the specific shape of the arc is not limited here; a person skilled in the art can select it according to the actual situation, and the center of curvature of the first weak portion 2121 may be located on one side away from the through hole 211 of the first weak portion 2121.

[0058] When the internal pressure of the battery cell reaches a threshold value and the pressure release structure 212 ruptures along the first weak portion 2121, the pressure release structure 212 surrounded by the arc-shaped first weak portion 2121 folds back toward the center of curvature of the first weak portion 2121 due to stress, and in this process, the part of the pressure release structure 212 surrounded by the first weak portion 2121 constantly moves away from the electrode terminal 21a, reducing the risk of the pressure release mechanism and the electrode terminal 21a coming into contact with each other, and is advantageous in improving the safety performance of the battery 100.

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

[0060] The rotating shaft portion 2122 refers to a transfer portion between the folded pressure relief structure 212 and the unfolded pressure relief structure 212 when a portion of the pressure relief structure 212 is folded back, and the folded pressure relief structure 212 rotates around this transfer portion as an axis. It should be noted that the rotating shaft portion 2122 is an area in the pressure relief structure where the first weak portion 2121 is not provided, and when the internal pressure of the battery cell 20 reaches a threshold value, the first weak portion 2121 does not rupture to cause the rotating shaft portion 2122 to rupture, and the rotating shaft portion 2122 can be used as a rotation axis of the folded pressure relief structure 212.

[0061] "The rotating shaft portion 2122 is located on one side away from the through hole 211 of the first weak portion 2121" means that the rotating shaft portion 2122 and the through hole 211 are respectively disposed on both sides of the first weak portion 2121. The area surrounded by the closed contour is the area of ​​the inverted pressure relief structure 212, so that the pressure relief structure 212 can be inverted at the designated area (the area surrounded by the closed contour), making it easy to distinguish each area in the pressure relief structure 212. In some embodiments, the rotating shaft portion 2122 and the projection of the first weak portion 2121 on one side away from the battery core assembly 23 of the end cap 21 are connected to form a closed contour, and the pressure relief structure 212 surrounded by the closed contour can be folded back around the rotating shaft portion 2122 as an axis.

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

[0063] In some embodiments of the present application, the thickness of the first weakened portion 2121 is less than the thickness of the remainder of the end cap 21 .

[0064] By setting the thickness of the first weak portion 2121 to be smaller than the thickness of the remaining portion of the end cap 21, the strength of the first weak portion 2121 is lower than the strength of the remaining portion of the end cap 21. In this manner, it is possible to ensure that the portion of the end cap 21 most likely to rupture is the first weak portion 2121, so that if the pressure relief structure 212 ruptures due to the internal pressure of the battery cell, the rupture position will be located at the first weak portion 2121, which makes it easy to set the rupture position of the pressure relief structure 212. In addition, forming the first weak portion 2121 by weakening the strength of the structure by changing the thickness is easier to operate than forming the first weak portion 2121 by weakening the strength of the structure by changing the material, which is advantageous in reducing the processing cost of the first weak portion 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 release 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 release 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 release structure 212, the strength of the rotating shaft portion 2122 is made smaller than the strength of the remaining portion of the pressure release structure 212, and the pressure release structure 212 surrounded by a closed contour is likely 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 made 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 release structure 212 surrounded by a closed contour still ruptures at the first weak portion 2121 and inverts about the rotating shaft portion 2122.

[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 release 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 release structure 212 is relatively low. The strength of the second weak portion 2123 is lower than the strength of other portions on the end cap 21. Specifically, the second weak portion 2123 and the first weak portion 2121 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.

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

[0070] In some embodiments of the present application, as shown in FIG. 7, the rotating shaft portion 2122 is provided with a first groove, 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 a groove formed on the rotating shaft portion 2122 by removing material through machining, which reduces the strength at this point and allows the pressure relief structure 212, which is surrounded by a closed contour, to be easily inverted at this point.

[0072] The "side close to the inside of the battery cell" refers to the side of the pressure relief structure 212 close to the battery core assembly 23 in the battery cell.

[0073] When the pressure relief structure 212 surrounded by a closed contour is inverted, it is inverted outward from one side approaching the inside of the battery cell around the rotating shaft portion 2122 as an axis, and the first groove is opened on one side of the pressure relief structure 212 approaching the inside of the battery cell, and a notch can be opened for the pressure relief structure 212 surrounded by a closed contour to be inverted, which further reduces the difficulty of inverting the pressure relief structure 212 surrounded by a closed contour.

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

[0075] The second groove is a groove formed on the first weak portion 2121 by a method of removing material through machining, which reduces the strength at this portion and allows the pressure relief structure 212 surrounded by a closed contour to be easily broken at this portion. In some embodiments, the second weak portion 2123 is formed by installing a third groove, which is also opened on a side of the pressure relief structure 212 away from the inside of the battery cell and connected to the second groove, and the structural parameters and size thereof are the same as those of the second groove.

[0076] The "side away from the inside of the battery cell" refers to the side of the pressure relief structure 212 away from the battery core assembly 23 in the battery cell.

[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, which is advantageous in making the residual material of the first vulnerable portion 2121 more susceptible to the internal pressure of the battery cell and making the first vulnerable portion 2121 more likely to rupture.

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

[0079] Here, the V-shaped groove is a groove whose cross section has a V-shape. In some embodiments, the first groove and the second groove may be configured as 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 can remove material and reduce the strength of the area where it is located.

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

[0081] In some embodiments of the present application, as shown in FIG. 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 connecting line of the two through holes 211.

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

[0083] The "perpendicular bisector of the center connection line of the two through holes 211" refers to a line segment that is formed with the center of the two through holes 211 as an end point, and the perpendicular bisector of this line segment. In some embodiments, the through hole 211 is configured as a circular hole, and can be fitted and attached with a pole as the electrode terminal 21a. As can be understood, the through hole 211 can also be configured as a square hole, a polygonal hole, or an irregular hole, as long as it can be fitted and attached as the electrode terminal 21a, and those skilled in the art can select according to the actual situation.

[0084] The symmetrical arrangement of the pressure relief structure 212 not only facilitates the positioning of the pressure relief structure 212 on the end cap 21, but also facilitates the processing and molding of the pressure relief structure 212.

[0085] In some embodiments of the present 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 can be other shapes such as a rectangle, which can be selected by those skilled in the art according to the actual situation, as long as the end cap 21 can seally cover one end of the battery cell.

[0087] The perpendicular bisector passing through the center of the end cap 21 makes it easy to determine the position of the through hole 211 and facilitates the processing and manufacturing of the through hole 211 in the end cap 21 .

[0088] In some embodiments of the present application, the central angle corresponding to the first weakened portion 2121 is less than or equal to 180°.

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

[0090] Since the central angle corresponding to the first weak portion 2121 is less than 180°, it can ensure that the first weak portion 2121 is located on the same side of the two through holes 211, and can avoid the first weak portion 2121 being installed across the central connecting line of the two through holes 211 due to being too large or for other reasons, which is advantageous in determining the placement position of the first weak portion 2121.

[0091] In some embodiments of the present application, as shown in FIG. 5, a recess 213 is provided in the end cap 21, and the pressure relief structure 212 is located 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 forming a recessed area in the end cap 21. The recess 213 may be formed on the end cap 21 using a processing method for removing material, such as turning, milling, cutting, grinding, etc., or may be integrally formed with the end cap 21 using a processing method, such as pressing, casting, roll pressing, etc., when processing and forming the end cap 21, and those skilled in the art may select according to actual circumstances.

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

[0094] The provision of the recess 213 can reduce the thickness here, and the pressure relief structure 212 is provided at the bottom of the recess 213, thereby making the thickness of the area where the pressure relief structure 212 is located relatively small and easy to rupture, which is helpful in realizing the exhaust and pressure relief function of the pressure relief mechanism.

[0095] In some embodiments of the present application, as shown in FIG. 7, recess 213 includes a recess step 2131 disposed along a sidewall of recess 213.

[0096] The recessed step 2131 is a step provided on a side wall of the recess 213, so that the recess 213 is recessed with a stepped staircase. In some embodiments, the wall surface of the side wall of the recessed step 2131 is provided at an obtuse angle with the plane of the bottom of the recess 213, that is, the side wall of the recessed step 2131 is provided with a slope, so that the recess 213 has a trumpet shape with an outward opening, which makes it easy to process the pressure relief structure 212 at the bottom of the recess 213. In some embodiments, the recessed step 2131 can have one step, two steps, or multiple steps, which makes it easy to process and form the recess 213.

[0097] The recessed step 2131 can prevent the recess 213 from becoming too deep and difficult to process, and is advantageous in improving the ease of processing the recess 213.

[0098] In some embodiments of the present application, the present application further provides an end cap assembly, which includes an end cap 21 according to any of the above methods and an electrode terminal 21a, and the electrode terminal 21a is drilled into the through hole 211.

[0099] Since this end cap assembly includes the end cap 21 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 21a, which is advantageous in improving the safety performance of the battery 100.

[0100] In some embodiments of the present application, the present application further provides a battery cell, which includes an end cap assembly and a case 22 according to the above technical solution, an opening is provided at one end of the case 22, and the end cap assembly is fitted over the opening.

[0101] An opening at one end of the case 22 is used to install the battery core assembly 23 of the battery cell into the case 22. An end cap assembly is installed to cover the opening, and the end cap assembly is connected to the opening to separate the inside and the outside of the case 22. In some embodiments, the end cap assembly is hermetically connected to the opening to prevent materials inside the case 22 from leaking.

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

[0103] In some embodiments of the present application, the present application further provides a power consuming device, which includes the battery 100 according to any of the above solutions, and the battery 100 is used to provide electrical energy to the power consuming device.

[0104] The power consuming device may be any one of the battery-powered appliances or systems described above.

[0105] According to some embodiments of the present application, as shown in FIG. 4 and FIG. 5, the present application provides an end cap 21 of a battery cell, which includes a pressure relief structure 212 and two through holes 211. The end cap 21 is provided with a recess 213. As shown in FIG. 7, a recess 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. The pressure relief structure 212 has a first weak part 2121, two second weak parts 2123 and a second weak part 2124. and the rotating shaft portion 2122, a closed contour is provided, the first weak portion 2121 is configured in an arc shape, and the center of curvature of the first weak portion 2121 is located on one side of the first weak portion 2121 away from the through hole 211, and when the internal pressure of the battery cell reaches a threshold value and the first weak portion 2121 is ruptured, the pressure relief structure 212 in the closed contour folds back to one side away from the through hole 211 around the rotating shaft portion 2122 as an axis, and releases the internal pressure of the battery cell. Here, the second groove in the first weak portion 2121 and the third groove in the second weak 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 portion 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 portion 2121 and folds back to one side away from the through hole 211 with the rotating shaft portion 2122 as an axis.

[0106] Although the present application has been described with reference to the preferred embodiments, various modifications may be made thereto and equivalents may be substituted for the components therein without departing from the scope of the present application. In particular, unless there is a structural conflict, each technical feature mentioned in each embodiment may be combined in any manner. The present application is not limited to the specific embodiments disclosed in the specification, but includes all technical solutions falling within the scope of the claims. [Explanation of symbols]

[0107] The reference numerals in the drawings in the specific embodiments are as follows: 1000: Vehicles, 100: battery, 200: controller, 300: motor, 10: housing; 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 portion, 2122: rotating shaft portion, 2123: second weak portion, 213: recess, 2131: recess step.

Claims

1. 1. An end cap for a battery cell, comprising: a through hole for attaching an electrode terminal of a battery cell; an end cap for a battery cell, the end cap comprising: a pressure relief structure, the first weak portion being configured in an arc shape, the center of curvature of the first weak portion being located on one side of the first weak portion away from the through hole, the pressure relief structure being configured to tear along the first weak portion when internal pressure of the battery cell reaches a threshold value, whereby at least a portion of the pressure relief structure folds back to one side away from the through hole to release the internal pressure.

2. The end cap of claim 1 , wherein the first weakened portion has a thickness less than a thickness of the remainder of the end cap.

3. 3. An end cap as described in claim 1 or 2, wherein the pressure relief structure further includes a rotating shaft portion located on one side away from the through hole of the first weak portion of the rotating shaft portion, and at least a portion of the pressure relief structure can be folded back around the rotating shaft portion as an axis.

4. The end cap of claim 3 , wherein the thickness of the pivot point is between the thickness of the first weakened portion and the thickness of the remainder of the pressure relief structure.

5. An end cap as described in any one of claims 3 to 4, wherein the pressure relief structure further includes two second weak portions, the two second weak portions are respectively installed at both ends of the first weak portion, the two second weak portions are both connected between the first weak portion and the rotating shaft portion, and the second weak portions, the rotating shaft portion and the first weak portions are connected to form a closed contour.

6. The end cap according to claim 3 , wherein a first groove is provided in the rotating shaft portion, and the first groove is opened on one side of the pressure relief structure that is close to the inside of the battery cell.

7. The end cap according to claim 6 , wherein the first weak portion is provided with a second groove, and the second groove is opened on one side of the pressure relief structure away from the inside of the battery cell.

8. The end cap of claim 7 , wherein the first groove and the second groove are both configured as V-grooves.

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

10. The end cap of claim 9 , wherein the perpendicular bisector passes through a center of the end cap.

11. The end cap of claim 1 , wherein a central angle corresponding to the first weakened portion is less than or equal to 180°.

12. The end cap according to claim 1 , wherein the end cap is provided with a recess, and the pressure relief structure is located at a bottom of the recess.

13. The end cap of claim 12 , wherein the recess includes a recess step disposed along a sidewall of the recess.

14. 1. An end cap assembly comprising: An end cap according to any one of claims 1 to 13; and an electrode terminal disposed in the through hole.

15. A battery cell, An end cap assembly as claimed in claim 14; a case having an opening at one end thereof, the end cap assembly being disposed over the opening.

16. A battery comprising the battery cell of claim 15.

17. 20. A power consuming device comprising the battery of claim 16, the battery being used to provide electrical energy.

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