Battery cells, batteries and power consuming devices

Abstract

This application discloses a battery cell, a battery, and a power consumption device. The battery cell includes a housing and an electrode terminal. The housing includes a wall having a withdrawal hole. The electrode terminal is disposed in the withdrawal hole, and the electrode terminal has a weakened area configured to break when the internal pressure of the housing exceeds a pressure threshold or the temperature exceeds a temperature threshold, thereby connecting the interior of the housing to the exterior of the housing. This method reduces the risk of the battery cell bursting.

Description

[Technical Field]

[0001] This application relates to the field of battery technology, and more particularly to battery cells, batteries and power consuming devices. [Background technology]

[0002] With the development of battery technology, battery cells are being applied in more and more fields, and are gradually replacing traditional petrochemical energy in the field of automotive power. Battery cells can store chemical energy and controllably convert it into electrical energy. In recyclable battery cells, the active material can be activated by charging after discharging for continued use.

[0003] A battery cell often includes an electrode assembly, electrode terminals, and a housing. The electrode assembly is electrically connected to the outside via the electrode terminals. The housing can accommodate the electrode assembly and provide support for the electrode assembly. An electrolyte can be contained inside the housing. The electrolyte and the active material on the electrode assembly can generate gas, increasing the internal pressure of the housing and creating a risk of the battery cell exploding. Summary of the Invention [Means for solving the problem]

[0004] In view of the above problems, the present application provides a battery cell, a battery, and a power consumption device that can reduce the risk of the battery cell exploding.

[0005] According to a first aspect, the present application provides a battery cell, the battery cell including a housing and an electrode terminal. The housing includes a wall portion having a withdrawal hole formed in the wall portion. The electrode terminal is provided in the withdrawal hole and has a weakened area formed in the electrode terminal. The weakened area is configured to break when an internal pressure of the housing exceeds a pressure threshold or a temperature exceeds a temperature threshold, thereby communicating the interior of the housing with the exterior of the housing.

[0006] In this manner, when the pressure exceeds a pressure threshold or the temperature exceeds a temperature threshold, the weakened area breaks and the excess gas inside the housing can be released, thereby reducing the risk of the battery cell bursting due to excessive internal pressure. Compared to placing the weakened area on the housing, placing the weakened area on the electrode terminal reduces the possibility of deformation of the housing and makes it easier to assemble the battery cell.

[0007] In some embodiments, the electrode terminal has a notched groove, and the weakened area is formed at the bottom of the notched groove.

[0008] This method facilitates processing of the weak area, and after the pressure exceeds the pressure threshold or the temperature exceeds the temperature threshold, the electrode terminal can break or bend along the notch groove under the action of pressure, allowing excessive gas inside the housing to be released, thereby reducing the risk of the battery cell bursting due to excessive internal pressure.

[0009] In some embodiments, the electrode terminal includes an insert portion and a first flange portion connected to each other, the insert portion is inserted into the pull-out hole along the axial direction of the electrode terminal, and in the radial direction of the electrode terminal, at least a portion of the outer surface of the first flange portion extends beyond the outer surface of the insert portion, and the portion of the first flange portion located around the pull-out hole is supported on the side of the wall portion facing the inside of the housing, and wherein the weakened region is located on the insert portion and / or the first flange portion.

[0010] With the above method, since the acting force of the pressure inside the housing on the insertion part and the first flange part is relatively large, by installing the weak area on the insertion part or the first flange part, the weak area can be made more sensitive to the pressure inside the housing, making it easier to achieve explosion-proof effects.

[0011] In some embodiments, the electrode terminal has a notch groove, the weakened area is formed at the bottom of the notch groove, and the notch groove is located on a side facing toward and / or away from the wall portion of the first flange portion.

[0012] While this method makes it easier to process the weakened area, the thickness of the first flange portion in the axial direction is generally relatively thin, so the notch groove is more sensitive to the internal pressure of the housing and is more likely to provide explosion-proof protection.

[0013] In some embodiments, the notched groove is positioned axially opposite at least a portion of the mating slit between the outer circumferential surface of the insert and the hole wall of the withdrawal hole.

[0014] In this manner, when the electrode terminal is broken or bent along the notch groove, it can be easily removed from the outlet hole, allowing for quick pressure relief and more effective explosion prevention.

[0015] In some embodiments, the radial width of the alignment slit is greater than the radial width of the notched groove.

[0016] In this manner, when the electrode terminal is broken or bent along the notch groove, it can be easily removed from the outlet hole, allowing for quick pressure relief and more effective explosion prevention.

[0017] In some embodiments, the axial projection of the radially outermost edge of the notched groove falls within the alignment slit.

[0018] In this manner, when the electrode terminal is broken or bent along the notch groove, it can be easily removed from the outlet hole, allowing for quick pressure relief and more effective explosion prevention.

[0019] In some embodiments, the radial width of the notched groove is greater than or equal to 0.5 mm and less than or equal to 2 mm in the radial direction.

[0020] In the radial direction, setting the radial width of the notch groove to 0.5 mm or more is advantageous in promoting the first flange portion to bend or break along the notch groove when the internal pressure of the housing exceeds a pressure threshold or the temperature exceeds a temperature threshold. Setting the radial width of the notch groove to 2 mm or less allows the first flange portion to maintain sufficient structural strength and improve the structural stability of the battery cell.

[0021] In some embodiments, the axial depth of the notch groove is greater than or equal to 0.1 times the axial thickness of the first flange portion and less than or equal to 0.9 times the axial thickness of the first flange portion.

[0022] Setting the axial depth of the notch groove to 0.1 times the axial thickness H0 of the first flange portion 230 is advantageous in promoting the first flange portion to bend or break along the notch groove when the internal pressure of the housing exceeds a pressure threshold or the temperature exceeds a temperature threshold. Setting the axial depth of the notch groove to 0.9 times or less the axial thickness of the first flange portion allows the first flange portion to maintain sufficient structural strength and improve the structural stability of the battery cell.

[0023] In some embodiments, at least a portion of the weakened region is located on the outer periphery of the insert.

[0024] This approach makes it easier to machine the weakened area while also making it easier for the insert to form a break along the weakened area.

[0025] In some embodiments, the electrode terminal includes an insert portion and a closing portion connected to each other, the insert portion is inserted into the pull-out hole along the axial direction of the electrode terminal, the insert portion is arranged cylindrically, the closing portion is closed at an end of the insert portion facing the inside of the housing to form a recess, and the weakened region is arranged on the closing portion.

[0026] In this manner, the thickness of the closing portion in the axial direction is relatively thin, so that the weakened area is more sensitive to the internal pressure of the housing and is more likely to exhibit an explosion-proof effect, and the gas inside the housing is allowed to enter the recess and be discharged through the recess.

[0027] In some embodiments, the closure is welded to the insert and forms a weld mark, and the weakened area is located within the weld mark.

[0028] This method allows the welding marks to be used as weak areas, simplifying the manufacturing process of the battery cell.

[0029] In some embodiments, the weakened area is disposed annularly about the central axis of the withdrawal hole.

[0030] In this way, the weak area is more sensitive to the internal pressure of the housing, and can achieve better explosion-proof effect.

[0031] In some embodiments, the electrode terminal includes an insertion portion and a closing portion connected to each other, the insertion portion is inserted into the drawing hole along the axial direction of the electrode terminal, the insertion portion is installed cylindrically, the closing portion is closed at an end of the insertion portion facing the inside of the housing to form a recess, the battery cell includes a closing member, the closing member is used to close the recess, and the battery cell is electrically connected to the outside via the closing member.

[0032] In this manner, the recess is closed by the closing member and electrically connected to the outside, thereby increasing the connection area between the battery cell and the external device.

[0033] In some embodiments, the recess is used to inject an electrolyte into the interior of the housing.

[0034] This method can simplify the structural complexity of the battery cell, reduce the occurrence of electrolyte leakage during the assembly process, and improve the assembly efficiency of the battery cell.

[0035] In some embodiments, the closure has an inlet hole that communicates the interior of the housing with the recess.

[0036] The above method is advantageous in that the electrolyte is sealed after injection is completed, thereby reducing the risk of electrolyte leakage.

[0037] In some embodiments, the battery cell further includes a current collector and an electrode assembly installed inside the housing, the current collector being used to connect a tab of the electrode assembly to an electrode terminal, and the side of the closing portion facing away from the recess being welded to the current collector.

[0038] The above method utilizes the thin thickness of the blocking portion to weld it to the current collector plate, making it easy to establish an electrical connection between the electrode terminal and the current collector plate from the side of the electrode terminal facing away from the current collector plate.

[0039] In some embodiments, the battery cell includes an electrode assembly, the housing includes a case and an end cap, one end of the case has an opening, the end cap covers the opening, the case includes a side wall and an end wall, the side wall surrounds the outside of the electrode assembly, the end wall is located opposite the opening, and the wall is the end cap or the end wall.

[0040] By using the above method to install the electrode terminals on the end caps or end walls, the assembly efficiency of the battery cell can be improved and the possibility of deformation of the end caps or end walls can be reduced, making the assembly of the battery cell easier.

[0041] In some embodiments, the melting point of the material of the electrode terminals is lower than the melting point of the material of the housing.

[0042] When welding the electrode terminal to another component using the above method, the relatively low melting point of the material of the electrode terminal is advantageous in reducing the welding temperature, while the relatively high melting point of the material of the housing can reduce the adverse effects of the welding process on the housing, thereby reducing the risk of leakage.

[0043] In some embodiments, the difference between the melting point of the material of the housing and the melting point of the material of the electrode terminals is greater than 300°C.

[0044] The above method is advantageous in reducing the welding temperature when welding the electrode terminal to other components, and also reduces the adverse effects of the welding process on the housing, thereby reducing the risk of leakage.

[0045] In some embodiments, the housing material includes steel and the electrode terminal material includes aluminum or copper.

[0046] In the above method, the housing is made of steel, which allows the housing to have a lower thermal expansion coefficient and good mechanical strength. Since the melting points of copper or aluminum are lower than those of steel, using copper or aluminum for the electrode terminals makes it easy to weld the electrode terminals and also makes it easy to process and form the copper or aluminum.

[0047] According to a second aspect, the present application provides a battery, the battery including the battery cell described above.

[0048] According to a third aspect, the present application provides a power consuming device, the power consuming device including the battery described above.

[0049] The above description is merely a summary of the technical solution of the present application, which can be implemented in accordance with the content of the specification, so as to make the technical means of the present application more clearly understood, and to make the above and other objectives, features and advantages of the present application more clearly comprehensible, the following particularly cites specific embodiments of the present application for description. [Brief explanation of the drawings]

[0050] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments. The drawings are for the purpose of illustrating the preferred embodiments only and are not to be considered as limitations on the present application, and like drawing reference numerals represent like elements in all drawings. In the drawings, [Figure 1] FIG. 1 is a structural schematic diagram of a vehicle according to one or more embodiments. [Figure 2] FIG. 1 is an exploded structural schematic diagram of a battery according to one or more embodiments. [Figure 3] FIG. 1 is a schematic cross-sectional view of a battery cell according to one or more embodiments. [Figure 4] 4 is a schematic cross-sectional view of the battery cell shown in FIG. 3 with some components hidden. [Figure 5] 4 is a schematic diagram of the underside structure of the battery cell after some of the components shown in FIG. 3 are hidden. [Figure 6] 4 is a structural schematic diagram of part A of the battery cell after hiding some of the components shown in FIG. 3. FIG. [Figure 7] 1 is a schematic diagram of a local structure of a battery cell according to one or more embodiments. FIG. [Figure 8] 1 is a schematic diagram of a local structure of a battery cell according to one or more embodiments. FIG. [Figure 9] 1 is a schematic diagram of a local structure of a battery cell according to one or more embodiments. FIG. [Figure 10] 1 is a schematic diagram of a local structure of a battery cell according to one or more embodiments. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0051] The following describes in detail the embodiments of the technical solution of the present application in conjunction with the drawings. The following embodiments are only used to more clearly explain the technical solution of the present application, and are merely examples, which do not limit the protection scope of the present application.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art of this application, and the terms used herein are only for describing specific embodiments and are not intended to limit this application. The terms "comprises" and "having" and any variations thereof in the specification and claims of this application and the description of the drawings above are intended to cover a non-exclusive "comprise."

[0053] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only for distinguishing different objects, and should not be understood as indicating or implying the relative importance or the number, specific order, or hierarchical relationship of the technical features shown. In the description of the embodiments of the present application, unless otherwise expressly and specifically limited, the meaning of "plurality" is two or more.

[0054] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. Appearances of this phrase in various locations throughout the specification do not necessarily all refer to the same embodiment, nor are they mutually exclusive, independent, or alternative embodiments. Those skilled in the art can explicitly or implicitly understand that the embodiments described herein can be combined with other embodiments.

[0055] In the description of the embodiments of this application, the term "and / or" is merely a relation describing related objects and indicates that three relations may exist. For example, A and / or B may represent three cases: A alone, a combination of A and B, and B alone. In addition, the character " / " in this specification generally indicates that the related objects before and after are in an "or" relationship.

[0056] In describing the embodiments of the present application, the term "plurality" refers to two or more (including two); similarly, "sets" refers to two or more (including two sets); and "plurality" refers to two or more (including two).

[0057] In describing the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "center," "longitudinal direction," "lateral direction," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial direction," "radial direction," and "circumferential direction" are orientations or positional relationships shown in the drawings, and are intended only to facilitate the description and simplification of the embodiments of the present application. They do not indicate or imply that the referred devices or elements must have a specific orientation or be configured and operated in a specific orientation, and therefore should not be understood as limitations on the embodiments of the present application.

[0058] In the description of the embodiments of the present application, unless otherwise clearly defined or limited, the technical terms "attached," "connected," "connected," "fixed," etc. should be understood in a broad sense, and may refer to, for example, a fixed connection, a detachable connection, or an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, an internal communication between two elements, or an interactive relationship between two elements. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application according to specific circumstances.

[0059] With the development of battery technology, battery cells are being applied in more and more fields, and are gradually replacing traditional chemical petroleum energy in the field of automotive power. Battery cells can store chemical energy and controllably convert chemical energy into electrical energy. In recyclable battery cells, the active material can be activated by charging after discharging for continued use.

[0060] A battery cell often includes an electrode assembly, electrode terminals, and a housing. The electrode assembly is electrically connected to the outside via the electrode terminals. The housing can accommodate the electrode assembly and provide support for the electrode assembly. An electrolyte can be contained inside the housing. The electrolyte and the active material on the electrode assembly can generate gas, increasing the internal pressure of the housing and creating a risk of the battery cell exploding.

[0061] In order to reduce the risk of battery cell rupture, the present application provides a weakened area in the electrode terminal, which is configured to communicate between the inside of the housing and the outside of the housing when the internal pressure of the housing exceeds a pressure threshold or the temperature exceeds a temperature threshold. Compared to providing the weakened area in the housing, providing the weakened area in the electrode terminal reduces the possibility of deformation of the housing, making it easier to assemble the battery cell.

[0062] Based on the above considerations, the present application provides a battery cell, a battery, and a power consumption device. After the pressure exceeds a pressure threshold or the temperature exceeds a temperature threshold, the electrode terminal can break or bend along the weakened area under the action of pressure or high temperature, allowing excessive gas inside the housing to be released, thereby reducing the risk of the battery cell bursting due to excessive internal pressure. By locating the weakened area on the insert portion or the first flange portion, the weakened area can be made more sensitive to the pressure inside the housing, making it easier to achieve explosion prevention. In this way, the risk of the battery cell bursting can be reduced.

[0063] The battery cells, batteries, and power consumption devices disclosed in the embodiments of the present application may be used in various energy storage systems that use batteries as power sources or batteries as energy storage elements. The power consumption devices may be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, battery-powered vehicles, electric cars, steamships, spacecraft, etc. Here, the electric toys may include stationary or mobile electric toys, such as game consoles, electric car toys, electric steamship toys, and electric airplane toys, and the spacecraft may include airplanes, rockets, space shuttles, and spaceships.

[0064] For convenience of explanation, the following embodiment will be described by taking an example in which the power consuming device of one embodiment of the present application is a vehicle 1000a.

[0065] Referring to FIG. 1 , the vehicle 1000a 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, a range extender vehicle, or the like. A battery 100a is installed inside the vehicle 1000a, and the battery 100a may be installed at the bottom, head, or tail of the vehicle 1000a. The battery 100a may be used to power the vehicle 1000a, for example, as an operating power source for the vehicle 1000a. The vehicle 1000a may further include a controller 200a and a motor 300a, and the controller 200a is used to control the battery 100a to power the motor 300a, for example, for starting the vehicle 1000a, navigating, and meeting operating power consumption needs during driving.

[0066] In some embodiments of the present application, the battery 100a may be used not only as an operating power source for the vehicle 1000a, but also as a driving power source for the vehicle 1000a, providing driving power to the vehicle 1000a in place of or in place of fuel oil or natural gas.

[0067] In some embodiments, battery 100a may be an energy storage device, including an energy storage container, an energy storage electrical cabinet, or the like.

[0068] The battery 100a referred to in the embodiments of this application is a single physical module containing one or more battery cells 1 to provide higher voltage and capacity.

[0069] In the embodiment of the present application, the battery cells 1 may be secondary batteries, which are battery cells that can be continuously used by activating the active material through charging after discharging. Each battery cell 1 may also be a primary battery.

[0070] The battery cell 1 includes, but is not limited to, a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel metal hydride battery, a nickel cadmium battery, a lead acid battery, etc. The battery cell 1 may be cylindrical, flat, rectangular, or have other shapes.

[0071] In some embodiments, the battery 100a may be a battery module, and when there are multiple battery cells 1, the multiple battery cells 1 are arranged and fixed to form one battery module.

[0072] In some embodiments, referring to FIG. 2, the battery 100a may be a battery pack, which includes a housing 10a and battery cells 1, and the battery cells 1 or battery modules are housed in the housing 10a.

[0073] In some embodiments, the chassis 10a may be used as part of the chassis structure of the vehicle 1000a. For example, a portion of the chassis 10a may form at least a portion of the floor of the vehicle 1000a, or a portion of the chassis 10a may form at least a portion of the cross members and stringers of the vehicle 1000a.

[0074] 2 , the battery 100a includes a housing 10a and a battery cell 1, and the battery cell 1 is housed in the housing 10a. Here, the housing 10a is used to provide a housing space for the battery cell 1, and the housing 10a may adopt various structures. In some embodiments, the housing 10a may include a first portion 11a and a second portion 12a, and the first portion 11a and the second portion 12a are placed over each other, and the first portion 11a and the second portion 12a collectively define a housing space for housing the battery cell 1. The second portion 12a may have a hollow structure with one end open, and the first portion 11a may have a plate-like structure, with the first portion 11a covering the open side of the second portion 12a so that the first portion 11a and the second portion 12a jointly define an accommodation space, and the first portion 11a and the second portion 12a may both have a hollow structure with one end open, with the open side of the first portion 11a covering the open side of the second portion 12a. Of course, the housing 10a formed by the first portion 11a and the second portion 12a may have various shapes, such as a cylinder or a rectangular parallelepiped.

[0075] The battery 100a may include multiple battery cells 1, and the multiple battery cells 1 may be connected in series, parallel, or series-parallel. A series-parallel connection means that the multiple battery cells 1 are connected both in series and in parallel. The multiple battery cells 1 may be directly connected in series, parallel, or series-parallel, and the entire battery cell set may be housed within the housing 10a. Alternatively, the battery 100a may be configured by first connecting the multiple battery cells 1 in series, parallel, or series-parallel to form a battery module, and then connecting the multiple battery modules in series, parallel, or series-parallel to form a single battery module housed within the housing 10a. The battery 100a may further include other structures, such as busbar members for electrically connecting the multiple battery cells 1.

[0076] 3, a battery cell 1 is the smallest unit that constitutes a battery 100a. In this embodiment, a cylindrical battery cell 1 will be described as an example. The battery cell 1 includes a housing 100, an electrode assembly 500, and other functional members.

[0077] In some embodiments, the housing 100 is used to package components such as the electrode assembly 500 and the electrolyte. The housing 100 may be a steel case, an aluminum case, a plastic case (e.g., polypropylene), a composite metal case (e.g., a copper-aluminum composite housing), or an aluminum-plastic film.

[0078] The housing 100 may include an end cap 120 and a case 110. The end cap 120 is a member that covers the opening 111 of the case 110 and isolates the internal environment of the battery cell 1 from the external environment. Without being limited thereto, the shape of the end cap 120 may be adapted to fit the shape of the case 110. Optionally, the end cap 120 may be made of a material (e.g., an aluminum alloy) with a certain hardness and strength. This makes the end cap 120 less likely to deform when subjected to a push-out collision, thereby providing the battery cell 1 with higher structural strength and improving safety performance. Functional members such as electrode terminals 200 may be provided on the end cap 120. The electrode terminals 200 may be used for electrical connection with the electrode assembly 500 to output or input electrical energy to or from the battery cell 1. In some embodiments, the end cap 120 may further be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the battery cell 1 reaches a threshold. The end cap 120 may be made of various materials, including, but not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. In some embodiments, an insulating material member may be further installed inside the end cap 120 to isolate the electrical connection members inside the case 110 from the end cap 120 and reduce the risk of short circuits. Illustratively, the insulating material member may be plastic, rubber, etc.

[0079] The case 110 is an assembly that fits into the end cap 120 to form an internal environment of the battery cell 1. The formed internal environment may be used to accommodate the electrode assembly 500, an electrolyte, and other components. The case 110 and the end cap 120 may be separate components, or an opening 111 may be provided on the case 110, and the end cap 120 may be placed over the opening 111 to form the internal environment of the battery cell 1. This is not a limitation, and the end cap 120 and the case 110 may be integrated. Specifically, the end cap 120 and the case 110 may first form a common connection surface before other components are inserted into the case, and then the end cap 120 may be placed over the case 110 when it is necessary to package the interior of the case 110. The case 110 may have various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the case 110 may be determined depending on the specific shape and size of the electrode assembly 500. The case 110 may be made of a variety of materials, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloys, plastics, and the like.

[0080] The electrode assembly 500 is a component where an electrochemical reaction occurs in the battery cell 1. The case 110 may contain one or more electrode assemblies 500.

[0081] In some embodiments, the electrode assembly 500 includes a positive electrode, a negative electrode, and a separator member. During charging and discharging of the battery cell, active ions (e.g., lithium ions) shuttle between the positive electrode and the negative electrode, absorbing and releasing them. The separator member, located between the positive electrode and the negative electrode, can prevent short-circuiting between the positive and negative electrodes and also allows the active ions to pass through.

[0082] In some embodiments, the positive electrode may be a positive plate, which may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0083] For example, a positive electrode current collector has two surfaces that face each other in the thickness direction of the positive electrode current collector, and a positive electrode active material is disposed on one or both of the two facing surfaces of the positive electrode current collector.

[0084] For example, the positive electrode current collector may be a metal foil sheet or a composite current collector. For example, the metal foil sheet may be silver-surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, a carbon electrode, carbon, nickel, or titanium. The composite current collector may include a polymer base layer and a metal layer. The composite current collector may be formed by forming a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymer substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0085] For example, the positive electrode active material may include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound thereof. However, the present application is not limited to these materials, and other conventional materials usable as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Here, examples of the lithium-containing phosphate may include, but are not limited to, at least one of lithium iron phosphate (e.g., LiFePO4 (which may be abbreviated as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (e.g., LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. Examples of the lithium transition metal oxide include lithium cobalt oxide (e.g., LiCoO2), lithium nickel oxide (e.g., LiNiO2), lithium manganese oxide (e.g., LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (e.g., LiNi 1 / 3 Co 1 / 3 Mn 1 / 3O2(NCM 333 (may be abbreviated as "LiNi") 0.5 Co 0.2 Mn 0.3 O2(NCM 523 (may be abbreviated as "LiNi") 0.5 Co 0.25 Mn 0.25 O2(NCM 211 (may be abbreviated as "LiNi") 0.6 Co 0.2 Mn 0.2 O2(NCM 622 (may be abbreviated as "LiNi") 0.8 Co 0.1 Mn 0.1 O2(NCM 811 ), lithium nickel cobalt aluminum oxide (e.g., LiNi 0.85 Co 0.15 Al 0.05 O2) and its modifying compounds, etc.

[0086] In some examples, the negative electrode may be a negative electrode plate, and the negative electrode plate may include a negative electrode current collector.

[0087] For example, the negative electrode current collector may be a metal foil sheet, a metal foam, or a composite current collector. For example, the metal foil sheet may be silver-surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, a carbon electrode, carbon, nickel, or titanium. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. The composite current collector may include a polymer base layer and a metal layer. The composite current collector may be formed by forming a metal material (such as copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymer substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0088] For example, the negative electrode plate may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0089] For example, the negative electrode current collector has two surfaces that face each other in the thickness direction thereof, and the negative electrode active material is disposed on either one or both of the two facing surfaces of the negative electrode current collector.

[0090] For example, the negative electrode active material may be a negative electrode active material for battery cells known in the art. For example, the negative electrode active material may include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicone-based material, a tin-based material, and lithium titanate. The silicone-based material may be selected from at least one of a silicone element, a silicone oxide, a silicone carbon composite, a silicone nitrogen composite, and a silicone alloy. The tin-based material may be selected from at least one of a tin element, a tin oxide, and a tin alloy. However, the present application is not limited to these materials and may also use conventional materials that can be used as negative electrode active materials in other batteries. These negative electrode active materials may be used alone or in combination.

[0091] In some examples, the material of the positive electrode current collector may be aluminum and the material of the negative electrode current collector may be copper.

[0092] In some embodiments, the electrode assembly 500 further includes a separator member disposed between the positive electrode and the negative electrode.

[0093] In some embodiments, the separator member is a separator. The present application does not particularly limit the type of separator, and any known porous structure separator with good chemical stability and mechanical stability may be selected.

[0094] For example, the main material of the separator may be selected from at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics. The separator may be a single-layer film or a multi-layer composite film, without any particular limitations. When the separator is a multi-layer composite film, the materials of each layer may be the same or different, without any particular limitations. The separator member may be a single member located between the positive and negative electrodes, or may be attached to the surfaces of the positive and negative electrodes.

[0095] In some embodiments, the separator member is a solid electrolyte that is disposed between the positive and negative electrodes and serves to transmit ions and separate the positive and negative electrodes.

[0096] In some embodiments, the battery cell further includes an electrolyte, which serves to conduct ions between the positive and negative electrodes. The present application does not specifically limit the type of electrolyte, and the electrolyte may be selected as needed. The electrolyte may be liquid, gel, or solid.

[0097] Here, the liquid electrolyte includes an electrolyte salt and a solvent.

[0098] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoro(oxalato)borate, lithium bis(oxalato)borate, lithium difluorobis(oxalato)phosphate, and lithium tetrafluoro(oxalato)phosphate.

[0099] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, ethyl methyl sulfone, and diethyl sulfone. The solvent may be selected from ether-based solvents. The ether-based solvent may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ether.

[0100] Here, the gel electrolyte includes a combination of a skeletal network with a polymer electrolyte and an ionic liquid-lithium salt.

[0101] Here, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0102] By way of example, the polymer solid electrolyte may be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquid-lithium salts, cellulose, and the like.

[0103] By way of example, the inorganic solid electrolyte may be one or more of an oxide solid electrolyte (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superionic conductor (lithium germanium phosphate sulfur, silver germanite sulfide), amorphous sulfide), a halide solid electrolyte, a nitride solid electrolyte, and a hydride solid electrolyte.

[0104] As an example, a composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0105] In some embodiments, the electrode assembly 500 is a wound structure, in which the positive and negative electrode plates are wound into the wound structure.

[0106] In some embodiments, the electrode assembly 500 is provided with tabs 501, which allow current to be extracted from the electrode assembly 500. The tabs include a positive tab and a negative tab. The positive and negative electrode tabs may be jointly located at one end of the body, or may be located at both ends of the body. During the charge and discharge process of the battery 100a, the positive and negative electrode active materials react with the electrolyte, and the tabs 501 are connected to the electrode terminals to form a current circuit.

[0107] According to some embodiments of the present application, as shown in Figures 3 to 5, a battery cell 1 of the present application includes a housing 100 and an electrode terminal 200. The housing 100 includes a wall portion 101, and a withdrawal hole 102 is provided in the wall portion 101. The electrode terminal 200 is provided in the withdrawal hole 102, and a weakened region 211 is provided in the electrode terminal 200. The weakened region 211 is configured to break when the internal pressure of the housing 100 exceeds a pressure threshold or when the internal temperature of the housing 100 exceeds a temperature threshold, thereby communicating the inside of the housing 100 with the outside of the housing 100.

[0108] The electrode terminal 200 can be attached to the housing 100 by being inserted into the drawing hole 102. Specifically, one end of the electrode terminal 200 may be disposed toward the inside of the housing 100 and used to electrically connect the electrode assembly 500 disposed within the housing 100. The other end of the electrode terminal 200 may be disposed toward the outside of the housing 100 and connected to the outside, thereby enabling charging and discharging of the electrode assembly 500.

[0109] The housing 100 may contain an electrolyte and an active material, which may generate gas and increase the internal pressure of the housing 100. If the gas continues to accumulate, the pressure inside the housing 100 may increase until it exceeds a pressure threshold. By providing a weakened region 211 on the electrode terminal 200, once the pressure exceeds the pressure threshold or the temperature exceeds a temperature threshold, the weakened region 211 breaks, connecting the interior of the housing 100 to the exterior of the housing 100, allowing the excess gas inside the housing 100 to be released.

[0110] If the battery cells 1 release energy too quickly, the temperature inside the housing 100 will often rise, and the high temperature can promote an increase in pressure. After the temperature exceeds a temperature threshold, the weakened area 211 can be destroyed, which is advantageous in alleviating the increase in pressure inside the housing 100.

[0111] By installing the battery cell 100 in this manner, it is possible to prevent a continuous increase in pressure inside the housing 100 and reduce the risk of the battery cell 1 exploding.

[0112] Alternatively, the weakened region 211 may be broken by the action of a pressure greater than the load that the weakened region 211 can withstand. The weakened region 211 may also be broken by the action of a high temperature, for example, the action of a high temperature weakens the strength of the weakened region 211, or the action of a high temperature causes the weakened region 211 to melt or deform.

[0113] In some embodiments, the electrode terminal 200 may break completely along the weakened region 211, and the broken portion may move away from the interior of the housing 100 due to the action of internal pressure of the housing 100. In other embodiments, the electrode terminal 200 may break partially along the weakened region 211, and the broken portion may bend away from the interior of the housing 100 due to the action of internal pressure of the housing 100.

[0114] If the weakened area 211 is provided on the housing 100, for example, on the wall 101, the structural strength of the housing 100 will be weakened, reducing the load-bearing capacity of the housing 100 and making the housing 100 more susceptible to deformation under force, which is detrimental to the assembly of the battery cell 1. For example, the housing 100 may have the function of supporting the electrode assembly 500, and it will be inconvenient to assemble the electrode assembly 500 after the housing 100 is deformed. Therefore, by providing the weakened area 211 on the electrode terminal 200, the possibility of deformation of the housing 100 can be reduced, making it easier to assemble the battery cell 1.

[0115] According to some embodiments of the present application, optionally, as shown in FIG. 6, the electrode terminal 200 is provided with a notched groove 210, and the weakened region 211 is formed at the bottom of the notched groove 210.

[0116] The notch groove 210 can be formed to form a weak area 211 on the electrode terminal 200. After the pressure exceeds a pressure threshold or the temperature exceeds a temperature threshold, the electrode terminal 200 can break or bend along the notch groove 210 due to the action of pressure or high temperature, allowing excessive gas inside the housing 100 to be discharged, thereby reducing the risk of the battery cell 1 bursting due to excessive internal pressure.

[0117] According to some embodiments of the present application, optionally, as shown in FIG. 6 , the electrode terminal 200 includes an insertion portion 220 and a first flange portion 230 that are connected to each other, the insertion portion 220 is inserted into the withdrawal hole 102 along the axial direction of the electrode terminal 200, at least a part of the outer circumferential surface of the first flange portion 230 protrudes from the outer circumferential surface of the insertion portion 220 in the radial direction of the electrode terminal 200, and the portion of the first flange portion 230 that is located around the withdrawal hole 102 is supported on the side of the wall portion 101 facing the inside of the housing 100, and the weakened region 211 is located on the insertion portion 220 and / or the first flange portion 230.

[0118] The axial direction of the electrode terminal 200 is the distance direction between the end of the electrode terminal 200 that faces toward the inside of the housing 100 and the end that faces away from the inside of the housing 100, and the radial direction of the electrode terminal 200 is the direction perpendicular to the axial direction of the electrode terminal 200. The axial direction and radial direction below both refer to the axial direction and radial direction of the electrode terminal 200 unless otherwise specified.

[0119] The electrode terminal 200 can be attached by installing the insertion portion 220 so that it is inserted into the drawing hole 102 along the axial direction of the electrode terminal 200. The first flange portion 230 is supported by the wall portion 101, thereby improving the connection stability between the electrode terminal 200 and the wall portion 101. In the radial direction of the electrode terminal 200, at least a portion of the outer circumferential surface of the first flange portion 230 protrudes from the outer circumferential surface of the insertion portion 220, and the first flange portion 230 is installed inside the housing 100. This allows the wall portion 101 to form a barrier against the first flange portion 230, thereby preventing the electrode terminal 200 from detaching from inside the housing 100.

[0120] The weakened region 211 may be provided on the insert 220, on the first flange 230, or simultaneously on the insert 220 and the first flange 230. By providing the weakened region 211 on the insert 220, when the pressure inside the housing 100 exceeds a pressure threshold or the temperature exceeds a temperature threshold, the insert 220 can break or bend along the weakened region 211, thereby allowing an excess amount of gas inside the housing 100 to be released. By providing the weakened region 211 on the first flange 230, when the pressure exceeds a pressure threshold or the temperature exceeds a temperature threshold due to internal actuation of the housing 100, the first flange 230 can break or bend along the weakened region 211, thereby allowing an excess amount of gas inside the housing 100 to be released.

[0121] Since the pressure inside the housing 100 acts on the insertion portion 220 and the first flange portion 230 with a relatively large force, by placing the weak area 211 on the insertion portion 220 or the first flange portion 230, the weak area 211 can be made more sensitive to the pressure inside the housing 100, and the explosion-proof effect can be more easily achieved.

[0122] According to some embodiments of the present application, optionally, as shown in Figures 6 to 8, the electrode terminal 200 is provided with a notch groove 210, the weakened area 211 is formed at the bottom of the notch groove 210, and the notch groove 210 is located on a side of the first flange portion 230 facing toward and / or away from the wall portion 101.

[0123] The side surface of the first flange portion 230 facing toward the wall portion 101 and the side surface of the first flange portion 230 facing away from the wall portion 101 may be distributed at intervals along the axial direction. The notched grooves 210 may be provided on the side surface of the first flange portion 230 facing toward the wall portion 101, or on the side surface of the first flange portion 230 facing away from the wall portion 101, or may be provided simultaneously on the side surface of the first flange portion 230 facing toward the wall portion 101 and the side surface of the first flange portion 230 facing away from the wall portion 101. The weakened region 211 may be formed by the notched grooves 210.

[0124] This arrangement facilitates the processing of the notch groove 210, and also makes the notch groove 210 more sensitive to the internal pressure of the housing 100 and more likely to provide explosion protection, since the first flange portion 230 generally has a relatively thin axial thickness. When the internal pressure of the housing 100 exceeds a pressure threshold or the temperature exceeds a temperature threshold, the first flange portion 230 can break or bend along the notch groove 210 in the axial direction, thereby realizing the explosion protection function of the notch groove 210.

[0125] Furthermore, in the radial direction, the first flange portion 230 and the insertion portion 220 are connected in a partially overlapping manner, and the cutout groove 210 may be installed in the overlapping portion between the first flange portion 230 and the insertion portion 220, which is advantageous in realizing the anti-rupture function of the cutout groove 210.

[0126] According to some embodiments of the present application, optionally, as shown in FIG. 6, the notch groove 210 is positioned axially opposite at least a portion of the alignment slit 240 between the outer peripheral surface of the insert 220 and the hole wall of the drawing hole 102.

[0127] By arranging the notch groove 210 in the axial direction opposite at least a portion of the alignment slit 240, when the electrode terminal 200 breaks or bends along the notch groove 210, it can easily come out of the withdrawal hole 102 without being blocked by the wall portion 101, allowing for quick pressure relief and more easily achieving the explosion-proof effect.

[0128] Furthermore, the battery cell 1 includes an insulating member 600, which is used to fill the mating slits 240 and can provide insulation and sealing effects. When the pressure inside the housing 100 exceeds a pressure threshold or the temperature exceeds a temperature threshold, the electrode terminal 200 can break or bend along the notched groove 210, causing the insulating member 600 to loosen from the mating slits 240, allowing gas to escape through the mating slits 240.

[0129] According to some embodiments of the present application, optionally, as shown in FIG. 6, the radial width D2 of the alignment slit 240 is greater than the radial width D1 of the notched groove 210 in the radial direction.

[0130] By setting the radial width D2 of the alignment slit 240 to be larger than the radial width D1 of the cutout groove 210 in the radial direction, when the electrode terminal 200 breaks or bends along the cutout groove 210, it becomes easier to separate from the withdrawal hole 102, allowing for quick pressure release and more effective explosion prevention.

[0131] Specifically, when the pressure inside the housing 100 exceeds a pressure threshold or the temperature exceeds a temperature threshold, the first flange portion 230 is split in the axial direction along the notch groove 210 to form a communicating groove penetrating the first flange portion 230. After the communicating groove is formed, gas accumulated inside the housing 100 can be discharged by passing through the communicating groove and the slit 240 in sequence.

[0132] According to some embodiments of the present application, optionally, as shown in FIG. 6, the axial projection of the radially outermost edge of the notched groove 210 enters the alignment slit 240 .

[0133] The notched groove 210 and the mating slit 240 may partially overlap in the radial direction. When the pressure inside the housing 100 exceeds a pressure threshold or the temperature exceeds a temperature threshold, the first flange portion 230 is subjected to pressure, and the pressure acts on the housing 100 in a direction away from the interior of the housing 100, causing the bottom of the notched groove 210 to deform away from the interior of the housing 100 until the first flange portion 230 breaks or bends along the notched groove 210.

[0134] By arranging the notch groove 210 so that the axial projection of the outermost radial edge thereof is within the mating slit 240, when the bottom of the notch groove 210 is deformed, the wall 101 can form a shield through the mating slit 240. When the electrode terminal 200 breaks or bends along the notch groove 210, it can easily come out of the outlet hole 102, allowing for quick pressure relief and better explosion-proofing.

[0135] Furthermore, the projection of the radially innermost edge of the cutout groove 210 along the axial direction may be inside the alignment slit 240 or outside the alignment slit 240 .

[0136] According to some embodiments of the present application, optionally, the radial width D1 of the notched groove 210 is 0.5 mm or more and 2 mm or less in the radial direction. For example, the radial width D1 of the notched groove 210 may be set to 0.6 mm, 0.8 mm, 1.0 mm, 1.4 mm, 1.6 mm, etc.

[0137] In the radial direction, setting the radial width D1 of the notched groove 210 to 0.5 mm or more is advantageous in promoting the first flange portion 230 to break or bend along the notched groove 210 when the internal pressure of the housing 100 exceeds a pressure threshold or the temperature exceeds a temperature threshold. Setting the radial width D1 of the notched groove 210 to 2 mm or less allows the first flange portion 230 to maintain sufficient structural strength and improve the structural stability of the battery cell 1.

[0138] According to some embodiments of the present application, optionally, the axial depth H1 of the notched groove 210 in the axial direction is greater than or equal to 0.1 times the axial thickness H0 of the first flange portion 230 and less than or equal to 0.9 times the axial thickness H0 of the first flange portion 230. For example, the axial depth H1 of the notched groove 210 may be equal to 0.1 times, 0.2 times, 0.3 times, 0.5 times, or 0.7 times the axial thickness H0 of the first flange portion 230. Also, for example, when the axial thickness H0 of the first flange portion 230 is equal to 1 mm, the radial width D1 of the notched groove 210 may be set to 0.2 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.8 mm, or the like.

[0139] Setting the axial depth H1 of the notched groove 210 to 0.1 times the axial thickness H0 of the first flange portion 230 in the axial direction is advantageous in promoting the first flange portion 230 to break or bend along the notched groove 210 when the internal pressure of the housing 100 exceeds a pressure threshold or the temperature exceeds a temperature threshold. Setting the axial depth H1 of the notched groove 210 to 0.9 times or less the axial thickness H0 of the first flange portion 230 allows the first flange portion 230 to maintain sufficient structural strength, which is advantageous in improving the structural stability of the battery cell 1.

[0140] According to some embodiments of the present application, optionally, at least a portion of the weakened area 211 is located on the outer periphery of the insert 220, as shown in FIG.

[0141] This arrangement makes it easier to process the weakened region 211 while also making it easier for the insert 220 to form a break along the weakened region 211 .

[0142] When the internal pressure of the housing 100 exceeds a pressure threshold or the temperature exceeds a temperature threshold, the insertion portion 220 can break or bend from the outer surface along the weakened area 211, thereby reducing the risk of the battery cell 1 exploding.

[0143] For example, the weakened area 211 may be formed at the bottom of the notch groove 210, the groove opening of the notch groove 210 may be opened on the outer peripheral surface of the insert portion 220, and the weakened area 211 may be located at the first flange portion 230, and when the internal pressure of the housing 100 exceeds a pressure threshold or the temperature exceeds a temperature threshold, the insert portion 220 and the weakened area 211 may break or bend synchronously along the notch groove 210.

[0144] According to some embodiments of the present application, optionally, as shown in FIG. 10 , the electrode terminal 200 includes an insertion portion 220 and a blocking portion 250 that are connected to each other, the insertion portion 220 is inserted into the drawing hole 102 along the axial direction of the electrode terminal 200, the insertion portion 220 is installed in a cylindrical shape, the blocking portion 250 is blocked at the end of the insertion portion 220 facing the inside of the housing 100 to form a recess 260, and the weakened region 211 is installed on the blocking portion 250.

[0145] Recess 260 may be formed on the side of closure 250 facing away from the interior of housing 100. When weakened area 211 is located on the side of closure 250 facing recess 260, it may communicate with recess 260.

[0146] The weak area 211 may be located on the side of the blocking portion 250 facing the recess 260, or on the side of the blocking portion 250 facing away from the recess 260, or may be located simultaneously on the side of the blocking portion 250 facing towards the recess 260 and on the side of the blocking portion 250 facing away from the recess 260.

[0147] The side of closure 250 facing toward recess 260 and the side of closure 250 facing away from recess 260 may be spaced apart along the axial direction. By locating weakened region 211 on the side of closure 250 facing toward and / or away from recess 260, when the pressure inside housing 100 exceeds a pressure threshold or the temperature exceeds a temperature threshold, closure 250 can break or fold along weakened region 211 to allow gas inside housing 100 to enter and escape through recess 260.

[0148] By providing the recess 260, the thickness of the closing portion 250 in the axial direction may be smaller than the thickness of the insertion portion 220. Because the thickness of the closing portion 250 in the axial direction is relatively thin, the weakened area 211 is more sensitive to the internal pressure of the housing 100 and is more likely to exhibit an explosion-proof effect.

[0149] According to some embodiments of the present application, optionally, as shown in FIG. 10 , the closure portion 250 is welded to the insert portion 220 to form a weld mark 700, and the weakened area 211 is located within the weld mark 700.

[0150] By controlling the welding process, the weld mark 700 can be used as the weakened region 211, and the weakened region 211 can be broken when the pressure inside the housing 100 exceeds a pressure threshold or the temperature exceeds a temperature threshold. By providing the battery cell 1 in this manner, the manufacturing process can be simplified.

[0151] In some embodiments, the battery cell 1 further includes a current collecting plate 400 disposed inside the housing 100. After the closing portion 250 and the current collecting plate 400 are welded together, a weld mark 700 is formed, and the closing portion 250 and the current collecting plate 400 are electrically connected via the weld mark 700. After the internal pressure of the housing 100 exceeds a pressure threshold or the temperature exceeds a temperature threshold, the closing portion 250 can break along the weakened region 211, thereby interrupting the current path between the electrode terminal 200 and the electrode assembly 500 and delaying the release of electrical energy.

[0152] In some other embodiments, the weakened region 211 is disposed on the closure 250 and surrounds the weld scar 700. With this arrangement, after the internal pressure of the housing 100 exceeds a pressure threshold or the temperature exceeds a temperature threshold, the closure 250 can break along the weakened region 211, thereby interrupting the current path between the electrode terminal 200 and the electrode assembly 500 and delaying the release of electrical energy.

[0153] According to some embodiments of the present application, optionally, the weakened area 211 is disposed in an annular shape around the central axis of the withdrawal hole 102, as shown in FIG.

[0154] By configuring the weakened region 211 in this manner, the weakened region 211 is more sensitive to the internal pressure of the housing 100, thereby achieving better explosion-proofing. Specifically, after the internal pressure of the housing 100 exceeds a pressure threshold or the temperature exceeds a temperature threshold, the electrode terminal 200 can break along the weakened region 211. In the radial direction, the portion of the electrode terminal 200 located inside the weakened region 211 and the portion located outside the weakened region 211 may be separated from each other. Alternatively, the portion of the electrode terminal 200 located inside the weakened region 211 may be bent away from the interior of the housing 100.

[0155] 3 and 6 , according to some embodiments of the present application, the electrode terminal 200 optionally includes an insertion portion 220 and a closing portion 250 that are connected to each other, the insertion portion 220 is inserted into the drawing hole 102 along the axial direction of the electrode terminal 200, the insertion portion 220 is cylindrical, and the closing portion 250 is closed at an end of the insertion portion 220 facing the inside of the housing 100 to form a recess 260, and the battery cell 1 includes a closing member 300 that is used to close the recess 260. The battery cell 1 is electrically connected to the outside via the closing member 300.

[0156] By installing the blocking member 300 to block the recess 260, the blocking member 300 may be used to increase the connection area between the battery cell 1 and an external device and to mitigate electrolyte leakage inside the battery cell 1.

[0157] Specifically, by installing the blocking member 300 and the electrode terminal 200 so that they are fixedly connected, a current path can be formed between the electrode assembly 500, the electrode terminal 200, and the blocking member 300. The electrode assembly 500 may be electrically connected to the outside via the electrode terminal 200 and the blocking member 300, in that order. For example, the battery cell 1 may be connected to a busbar via the blocking member 300. A busbar is a connecting bar with a multi-layer composite structure, and can connect multiple battery cells 1 in series or parallel by welding or bolts.

[0158] Furthermore, a second flange portion 270 may be formed at the end of the electrode terminal 200 that faces away from the inside of the housing 100, the opening of the recess 260 may be located at the second flange portion 270, the closing member 300 may be connected to the second flange portion 270 to close the recess 260, and the electrode terminal 200 may be electrically connected to the outside via the closing member 300. The wall portion 101 may be stopped between the first flange portion 230 and the second flange portion 270 to limit the relative movement between the electrode terminal 200 and the housing 100.

[0159] According to some embodiments of the present application, optionally, as shown in FIG. 3, recess 260 is used to inject an electrolyte into the interior of housing 100 .

[0160] During the production process of the battery cell 1, the recess 260 can communicate with the interior of the housing 100, allowing electrolyte to be injected into the housing 100 through the recess 260. By providing the recess 260, after the electrode terminal 200 and the housing 100 are assembled and connected, the recess 260 can be used to inject electrolyte, and the recess 260 can then be closed using the closing member 300. This simplifies the structural complexity of the battery cell 1, reduces the occurrence of electrolyte leakage during the assembly process, and improves the assembly efficiency of the battery cell 1.

[0161] According to some embodiments of the present application, optionally, as shown in FIG. 3, the blocking portion 250 is provided with an inlet hole 251, which connects the interior of the housing 100 with the recess 260.

[0162] When injecting electrolyte during the assembly process of the battery cell 1, the electrolyte can pass through the recess 260 and the injection hole 251, and then enter the interior of the housing 100. The provision of the injection hole 251 is advantageous for sealing the housing after the electrolyte injection is complete, reducing the risk of electrolyte leakage. The closure part 250 is thinner than the insertion part 220, and providing the injection hole 251 in the closure part 250 is advantageous for forming the injection hole 251 and facilitating the injection of electrolyte.

[0163] Alternatively, both axial ends of the liquid inlet hole 251 may communicate with the recess 260 and the interior of the housing 100, respectively.

[0164] When the weakened region 211 is provided in the closure 250, in order to realize the function of the weakened region 211, the closure for the inlet hole 251 is configured so as not to be broken by pressure within a pressure threshold range or temperature within a temperature threshold range inside the housing 100. Of course, in some embodiments, the electrode terminal 200 may not have the inlet hole 251.

[0165] According to some embodiments of the present application, optionally, as shown in FIG. 3 , the battery cell 1 further includes a current collector 400 and an electrode assembly 500 installed inside the housing 100, the current collector 400 is used to connect a tab 501 of the electrode assembly 500 to the electrode terminal 200, and the side of the blocking portion 250 away from the recess 260 is welded to the current collector 400.

[0166] The current collecting plate 400 may be installed between the electrode terminal 200 and the electrode assembly 500, and serves to form a current path between the electrode terminal 200 and the electrode assembly 500. By installing the current collecting plate 400, electrical connection between the electrode terminal 200 and the electrode assembly 500 can be easily achieved. By utilizing the thin thickness of the blocking portion 250 and welding it to the current collecting plate 400, electrical connection between the electrode terminal 200 and the current collecting plate 400 can be easily achieved from the side of the electrode terminal 200 that is away from the current collecting plate 400.

[0167] According to some embodiments of the present application, optionally, as shown in FIG. 3 , the battery cell 1 includes an electrode assembly 500, the housing 100 includes a case 110 and an end cap 120, one end of the case 110 has an opening 111, the end cap 120 covers the opening 111, the case 110 includes a side wall 112 and an end wall 113, the side wall 112 surrounds the outside of the electrode assembly 500, the end wall 113 is located opposite the opening 111, and the wall portion 101 is the end cap 120 or the end wall 113.

[0168] In the above embodiment, the wall 101 is an end wall 113. In other embodiments, the wall 101 may be an end cap 120.

[0169] Since the end caps 120 or the end walls 113 are flatter than the side walls 112, the assembly efficiency of the battery cell 1 can be improved by placing the electrode terminals 200 on the end caps 120 or the end walls 113.

[0170] The electrode assembly 500 may be supported by the end cap 120 or the end wall 113 inside the housing 100. If the weakened region 211 is provided in the end cap 120 or the end wall 113, the structural strength of the end cap 120 or the end wall 113 will be weakened, reducing the load-bearing capacity of the end cap 120 or the end wall 113 and making the end cap 120 or the end wall 113 more susceptible to deformation under force, which is detrimental to the progress of the assembly process of the battery cell 1. Therefore, by providing the weakened region 211 in the electrode terminal 200, the possibility of deformation of the end cap 120 or the end wall 113 can be reduced, making it easier to assemble the battery cell 1.

[0171] According to some embodiments of the present application, optionally, the melting point of the material of the electrode terminal 200 is lower than the melting point of the material of the housing 100 .

[0172] When welding the electrode terminal 200 to another component, the relatively low melting point of the material of the electrode terminal 200 is advantageous in reducing the welding temperature, while the relatively high melting point of the material of the housing 100 reduces the adverse effects of the welding process on the housing 100, thereby reducing the risk of leakage.

[0173] According to some embodiments of the present application, optionally, the difference between the melting point of the material of the housing 100 and the melting point of the material of the electrode terminal 200 is greater than 300°C.

[0174] Such an installation is advantageous in reducing the welding temperature when welding the electrode terminal 200 to other components, and also reduces the risk of leakage by reducing damage to the housing 100 during the welding process.

[0175] According to some embodiments of the present application, optionally, the material of the housing 100 includes steel, and the material of the electrode terminal 200 includes aluminum or copper.

[0176] By using steel as the material for the housing 100, it is possible to provide the housing 100 with a lower coefficient of thermal expansion and good mechanical strength. Copper or aluminum have a lower melting point than steel, so if the electrode terminal 200 is made of copper or aluminum, it becomes easier to weld the electrode terminal 200 and also makes it easier to process and form the copper or aluminum.

[0177] According to some embodiments of the present application, as optionally shown in Figures 3 to 10, the battery cell 1 includes a housing 100 and an electrode terminal 200. The housing 100 includes a wall portion 101, and a withdrawal hole 102 is provided in the wall portion 101. The electrode terminal 200 is provided in the withdrawal hole 102, and a weakened area 211 is provided in the electrode terminal 200. The weakened area 211 is configured to break when the internal pressure of the housing 100 exceeds a pressure threshold or when the temperature exceeds a threshold, thereby connecting the inside of the housing 100 with the outside of the housing 100. The electrode terminal 200 is provided with a notched groove 210, and the weakened area 211 is formed at the bottom of the notched groove 210. The electrode terminal 200 includes an insertion portion 220 and a first flange portion 230 that are connected to each other. The insertion portion 220 is inserted into the withdrawal hole 102 along the axial direction of the electrode terminal 200. In the radial direction of the electrode terminal 200, at least a part of the outer circumferential surface of the first flange portion 230 protrudes from the outer circumferential surface of the insertion portion 220. The portion of the first flange portion 230 that is located around the withdrawal hole 102 is supported on the side of the wall portion 101 that faces the inside of the housing 100. Here, a weakened region 211 is located on the insertion portion 220 and / or the first flange portion 230. The electrode terminal 200 is provided with a notched groove 210. The weakened region 211 is formed at the bottom of the notched groove 210. The notched groove 210 is located on the side of the first flange portion 230 that faces toward and / or away from the wall portion 101. The notched groove 210 is disposed axially opposite at least a portion of the mating slit 240 between the outer circumferential surface of the insertion portion 220 and the hole wall of the drawing hole 102. In the radial direction, the radial width D2 of the mating slit 240 is greater than the radial width D1 of the notched groove 210. The axial projection of the outermost edge of the notched groove 210 is within the mating slit 240. In the radial direction, the radial width D1 of the notched groove 210 is 0.5 mm or more and 2 mm or less. In the axial direction, the axial depth H1 of the notched groove 210 is 0.1 times or more the axial thickness H0 of the first flange portion 230 and 0.9 times or less the axial thickness H0 of the first flange portion 230. At least a portion of the weakened region 211 is located on the outer circumferential surface of the insertion portion 220.The electrode terminal 200 includes an insertion portion 220 and a closing portion 250 which are connected to each other. The insertion portion 220 is inserted into the withdrawal hole 102 along the axial direction of the electrode terminal 200. The insertion portion 220 is arranged cylindrically. The closing portion 250 is closed at the end of the insertion portion 220 facing the inside of the housing 100 to form a recess 260. A weakened region 211 is arranged on the closing portion 250. The closing portion 250 is welded to the insertion portion 220 to form a weld mark 700. The weakened region 211 is arranged in an annular shape around the central axis of the withdrawal hole 102. The electrode terminal 200 includes an insertion portion 220 and a closing portion 250 that are connected to each other. The insertion portion 220 is inserted into the lead-out hole 102 along the axial direction of the electrode terminal 200 and is cylindrical. The closing portion 250 closes the end of the insertion portion 220 that faces the inside of the housing 100, forming a recess 260. The battery cell 1 includes a closing member 300 that is used to close the recess 260, and the battery cell 1 is electrically connected to the outside via the closing member 300. The recess 260 is used to inject an electrolyte into the inside of the housing 100. The closing portion 250 is provided with a liquid injection hole 251 that connects the inside of the housing 100 with the recess 260. The battery cell 1 further includes a current collector 400 and an electrode assembly 500 installed inside the housing 100. The current collector 400 is used to connect a tab 501 of the electrode assembly 500 to the electrode terminal 200, and the side of the closing portion 250 facing away from the recess 260 is welded to the current collector 400. The battery cell 1 includes the electrode assembly 500. The housing 100 includes a case 110 and an end cap 120. One end of the case 110 has an opening 111. The end cap 120 covers the opening 111. The case 110 includes a side wall 112 and an end wall 113. The side wall 112 surrounds the outside of the electrode assembly 500. The end wall 113 is installed opposite the opening 111. The wall 101 is the end cap 120 or the end wall 113. The melting point of the material of the electrode terminal 200 is lower than the melting point of the material of the housing 100. The difference between the melting points of the material of the housing 100 and the material of the electrode terminal 200 is greater than 300°C.The material of the housing 100 includes steel, and the material of the electrode terminal 200 includes aluminum or copper.

[0178] According to some embodiments of the present application, as shown in Fig. 2, a battery 100a includes the above-described battery cell 1. This arrangement reduces the risk of the housing 100 exploding, thereby improving the stability and reliability of the operation of the battery cell 1, and further improving the stability and reliability of the operation of the battery 100a.

[0179] According to some embodiments of the present application, a power consuming device includes the above-mentioned battery 100a, as shown in Figure 1. This arrangement improves the stability and reliability of the battery cell 1 during operation, thereby improving the stability and reliability of the battery 100a during operation, and further improving the stability and reliability of the power consuming device during operation.

[0180] To summarize, in the embodiments of the present application, after the pressure exceeds a pressure threshold or the temperature exceeds a temperature threshold, the electrode terminal 200 can be broken or bent along the weak region 211 under the action of pressure, thereby realizing communication between the inside of the housing 100 and the outside of the housing 100, allowing excessive gas inside the housing 100 to be discharged, reducing the risk of the battery cell 1 bursting due to excessive internal pressure, reducing the possibility of deformation of the housing 100, and facilitating assembly of the battery cell 1.

[0181] Finally, it should be noted that the above embodiments are merely intended to illustrate the technical solutions of the present application and are not intended to limit the same. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified or some or all of the technical features may be replaced with equivalents. Such modifications or replacements do not deviate from the essence of the relevant technical solutions from the scope of the technical solutions of the embodiments of the present application, and all of these should be included within the scope of the claims and description of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in the embodiments may be combined in any manner. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions within the scope of the claims. [Explanation of symbols]

[0182] The reference numerals in the drawings in the detailed description of the invention are as follows: 1000a vehicle, 100A battery, 200A controller, 300A motor, 10a housing, 11a first part, 12a second part, D1 radial width of the notch groove, D2 radial width of the alignment slit, H0 axial thickness of the first flange portion, H1 axial depth of the notch groove, 1 battery cell, 100 housing, 101 wall portion, 102 drawer hole, 200 electrode terminal, 210 notch groove, 211 weak area, 220 insertion portion, 230 first flange portion, 240 alignment slit, 250 blocking portion, 260 recess, 270 second flange portion, 300 blocking member, 251 injection hole, 400 current collecting plate, 500 electrode assembly, 501 tab, 110 case, 120 end cap, 111 opening, 112 side wall, 113 end wall, 600 insulating member, 700 welding marks.

Claims

1. A battery cell, a housing including a wall portion having a withdrawal hole; a weak area disposed in the withdrawal hole, the weak area being configured to break when the internal pressure or temperature of the housing exceeds a pressure threshold, thereby connecting the inside of the housing with the outside of the housing.

2. 2. The battery cell according to claim 1, wherein the electrode terminal has a notched groove, and the weakened area is formed at the bottom of the notched groove.

3. 2. The battery cell according to claim 1, wherein the electrode terminal includes an insertion portion and a first flange portion connected to each other, the insertion portion is inserted into the pull-out hole along the axial direction of the electrode terminal, at least a part of the outer circumferential surface of the first flange portion protrudes from the outer circumferential surface of the insertion portion in the radial direction of the electrode terminal, and a portion of the first flange portion located around the pull-out hole is supported on a side of the wall portion facing the inside of the housing, and the weakened region is located on the insertion portion and / or the first flange portion.

4. 4. The battery cell according to claim 3, wherein the electrode terminal has a notch groove, the weakened area is formed at the bottom of the notch groove, and the notch groove is located on a side surface of the first flange portion facing toward and / or away from the wall portion.

5. The battery cell according to claim 4 , wherein the notched groove is disposed in the axial direction opposite at least a portion of a matching slit between an outer peripheral surface of the insertion portion and a hole wall of the withdrawal hole.

6. The battery cell according to claim 5 , wherein the width of the alignment slit in the radial direction is greater than the width of the notched groove in the radial direction.

7. The battery cell according to claim 6 , wherein a projection of the outermost edge of the cutout groove in the radial direction along the axial direction is within the alignment slit.

8. The battery cell according to claim 7 , wherein the width of the notched groove in the radial direction is 0.5 mm or more and 2 mm or less.

9. 9. The battery cell according to claim 8, wherein the axial depth of the cutout groove is equal to or greater than 0.1 times the axial thickness of the first flange portion and equal to or less than 0.9 times the axial thickness of the first flange portion.

10. The battery cell according to claim 3 , wherein at least a portion of the weakened area is located on an outer circumferential surface of the insertion portion.

11. 2. The battery cell according to claim 1, wherein the electrode terminal includes an insertion portion and a closing portion connected to each other, the insertion portion is inserted into the lead-out hole along the axial direction of the electrode terminal, the insertion portion is arranged cylindrically, the closing portion is closed at an end of the insertion portion facing the inside of the housing to form a recess, and the weakened region is arranged on the closing portion.

12. The battery cell according to claim 11 , wherein the closing portion is welded to the insertion portion to form a weld mark, and the weakened area is located within the weld mark.

13. The battery cell according to claim 1 , wherein the weakened area is disposed in an annular shape around the central axis of the extraction hole.

14. 2. The battery cell according to claim 1, wherein the electrode terminal includes an insertion portion and a closing portion connected to each other, the insertion portion is inserted into the lead-out hole along the axial direction of the electrode terminal, the insertion portion is installed in a cylindrical shape, the closing portion is closed at an end of the insertion portion facing the inside of the housing to form a recess, the battery cell includes a closing member, the closing member is used to close the recess, and the battery cell is electrically connected to the outside via the closing member.

15. 15. The battery cell according to claim 14, wherein the recess is used to inject an electrolyte into the interior of the housing.

16. 16. The battery cell according to claim 15, wherein the closing portion has a liquid inlet hole that connects the interior of the housing with the recess.

17. 15. The battery cell of claim 14, further comprising a current collector and an electrode assembly installed inside the housing, the current collector being used to connect a tab of the electrode assembly to the electrode terminal, and a side of the closing portion away from the recess being welded to the current collector.

18. 18. The battery cell according to claim 1, wherein the battery cell includes an electrode assembly, the housing includes a case and an end cap, one end of the case has an opening, the end cap covers the opening, the case includes a side wall and an end wall, the side wall surrounds the outside of the electrode assembly, the end wall is located opposite the opening, and the wall portion is the end cap or the end wall.

19. 2. The battery cell according to claim 1, wherein the melting point of the material of the electrode terminal is lower than the melting point of the material of the housing.

20. 20. The battery cell according to claim 19, wherein the difference between the melting point of the material of the housing and the melting point of the material of the electrode terminal is greater than 300°C.

21. 2. The battery cell according to claim 1, wherein the housing is made of a material including steel, and the electrode terminals are made of a material including aluminum or copper.

22. A battery comprising the battery cell of any one of claims 1 to 21.

23. 23. A power consuming device comprising the battery of claim 22.

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