Battery cells, batteries, and power consumption devices

Abstract

This application discloses a battery cell, a battery, and a power consumption device. The battery cell includes an outer case, an electrode assembly, and an electrode terminal. The outer case includes a wall portion with an electrode lead-out hole. At least a portion of the electrode assembly is housed within the outer case, and the electrode assembly includes a tab. The electrode terminal is installed on the wall portion and covers at least a portion of the electrode lead-out hole. The electrode terminal is electrically connected to the tab. The electrode terminal is deformable when the internal pressure or temperature of the outer case reaches a threshold value, thereby communicating the interior space and the exterior space of the outer case through the electrode lead-out hole.

Description

Cross-reference of related applications

[0001] This application claims priority to the Chinese patent application filed on April 12, 2023, application number 202310389480.4, titled "Battery Cell, Battery and Power Consumption Device," the entirety of which is incorporated herein by reference. [Technical Field]

[0002] This application relates to the field of batteries, and more particularly to battery cells, batteries, and power consumption devices. [Background technology]

[0003] With advancements in battery technology, battery cells are being applied in an increasing number of fields, and are replacing conventional petrochemical energy in the automotive power sector. Battery cells can store chemical energy and controllably convert that chemical energy into electrical energy. In reusable battery cells, the active material can be activated by discharging and then recharging, allowing for continued use.

[0004] Improving the reliability of battery cells is a key area of ​​research in the industry. [Overview of the project]

[0005] This invention provides a battery cell, a battery, and a power consumption device that can improve their reliability.

[0006] In a first embodiment, the present application provides a battery cell including an outer case, an electrode assembly, and electrode terminals. The outer case includes a wall portion provided with electrode exit holes. At least a portion of the electrode assembly is housed within the outer case, and the electrode assembly includes tabs. Electrode terminals are mounted on the wall portion and cover at least a portion of the electrode exit holes. The electrode terminals are electrically connected to the tabs. At least a portion of the electrode terminals is deformable when the internal pressure or temperature of the outer case reaches a threshold, thereby enabling communication between the internal and external spaces of the outer case through the electrode exit holes and allowing gases inside the outer case to be discharged.

[0007] When the internal pressure or temperature of the outer casing reaches a threshold, the above technical solution utilizes the deformation of the electrode terminals to connect the internal and external spaces of the outer casing, thereby releasing the internal gas and pressure of the outer casing and reducing the risk of the battery cell exploding. Compared to a method in which a depressurization mechanism is additionally installed in the outer casing, the above technical solution simplifies the structure of the battery cell and reduces the cost of the battery cell.

[0008] In some embodiments, at least a portion of the electrode terminals can detach from the wall when the internal pressure or temperature of the outer case reaches a threshold.

[0009] When at least a portion of the electrode terminals detaches from the wall, at least a portion of the electrode lead-out hole is no longer covered by the electrode terminals, allowing the electrode lead-out hole to communicate with the internal and external spaces of the outer case. This releases internal gas from the battery cell, reducing the internal pressure and temperature of the battery cell.

[0010] In some embodiments, the electrode terminals include projections that extend radially from the wall of the electrode exit hole, the projections being located on the side of the wall facing the electrode assembly, and the projections being deformable when the internal pressure or temperature of the outer case reaches a threshold.

[0011] While the battery cell is operating normally, the wall can hold the protrusion in place, thereby reducing the risk of the electrode terminals escaping through the electrode lead-out holes. If the internal pressure or temperature of the outer case reaches a threshold, the protrusion can deform, causing the wall to no longer hold it in place, the electrode terminals to escape through the electrode lead-out holes, the internal and external spaces of the outer case to communicate through the electrode lead-out holes, and gases inside the outer case to be released through the electrode lead-out holes, reducing the risk of the battery cell exploding.

[0012] In some embodiments, when the maximum dimension L1 that the protrusion projects from the hole wall of the electrode lead-out hole and the minimum distance L2 between the peripheral edge of the wall portion and the hole wall of the electrode lead-out hole are defined, L1 and L2 satisfy 0.1 ≦ L1 / L2 ≦ 0.5.

[0013] By limiting the value of L1 / L2 to 0.5 or less, it can be deformed immediately when the internal pressure or temperature of the outer case reaches the threshold value, improving the reliability of the battery cell. By limiting the value of L1 / L2 to 0.1 or more, the stability of the electrode terminal in the wall portion can be improved, reducing the risk of the electrode terminal falling off when the battery cell is subjected to an external impact.

[0014] In some embodiments, when the maximum dimension L1 that the protrusion projects from the hole wall of the electrode lead-out hole and the maximum thickness T1 of the protrusion are defined, L1 and T1 are such that 0.25 mm ≦ L1 × T1 ≦ 25 mm 2 is satisfied.

[0015] By limiting the value of L1 × T1 to 25 mm 2 or less, it can be deformed immediately when the internal pressure or temperature of the outer case reaches the threshold value, improving the reliability of the battery cell. By limiting the value of L1 × T1 to 0.25 mm 2 or more, the stability of the electrode terminal in the wall portion can be improved, reducing the risk of the electrode terminal falling off when the battery cell is subjected to an external impact.

[0016] In some embodiments, T1 is 0.5 mm to 5 mm. By limiting T1 to 0.5 mm to 5 mm, it can be deformed immediately when the internal pressure or temperature of the outer case reaches the threshold value, and at the same time, the risk of the electrode terminal falling off when the battery cell is subjected to an external impact is reduced.

[0017] In some embodiments, in the direction from the central axis of the electrode lead-out hole toward the outer peripheral edge of the protrusion, the thickness of at least a part of the protrusion gradually decreases.

[0018] By incorporating a thickness-changing region in the protruding portion where the thickness gradually decreases, the protruding portion becomes more easily deformed by the action of internal pressure, thereby immediately reducing the pressure and improving the reliability of the battery cell.

[0019] In some embodiments, the projection has a first surface facing the wall, the wall has a second surface facing the projection, the second surface is perpendicular to the thickness direction of the wall, the first surface is inclined with respect to the second surface toward the electrode assembly, and in the thickness direction of the wall, the distance between the second surface and one end of the first surface away from the electrode extraction hole is greater than the distance between the second surface and one end of the first surface closer to the electrode extraction hole.

[0020] When the internal pressure or temperature of the outer casing reaches a threshold, the inclined first surface can induce deformation of the protrusion, thereby facilitating its withdrawal from the electrode exit hole, which is immediately depressurized, improving the reliability of the battery cell.

[0021] In some embodiments, the electrode terminals include a terminal body and a first stopper portion that are connected to each other, with at least a portion of the terminal body housed in an electrode lead-out hole, and the first stopper portion being located on the side facing the electrode assembly of the wall and protruding from the outer circumferential surface of the terminal body. The first stopper portion includes a protruding portion.

[0022] By positioning the terminal body so that it fits into the electrode lead-out hole, it becomes easier to connect the electrode terminal to other components outside the battery cell. The wall portion forms a barrier against the protruding portion, thereby limiting the electrode terminal from detaching from the inside of the outer case.

[0023] In some embodiments, a weakened portion is provided in the first stopper portion, and the first stopper portion is capable of bending or breaking along the weakened portion when the internal pressure or temperature of the outer case reaches a threshold.

[0024] By installing a thin section in the first stopper, when the internal pressure or temperature of the outer case reaches a threshold, the difficulty of deformation of the first stopper is reduced, allowing the first stopper to bend or break at a predetermined position. This connects the internal and external spaces of the outer case through the electrode extraction holes, reducing the risk of the battery cell exploding.

[0025] In some embodiments, at least a portion of the projection of the thin portion in the thickness direction of the wall is located within the electrode extraction hole.

[0026] The above technical solution allows the curved portion of the first stopper to be brought closer to the electrode extraction hole when the internal pressure or temperature of the outer case reaches a threshold, thereby making it easier to pull out the first stopper from inside the electrode extraction hole.

[0027] In some embodiments, the first stopper portion includes a protruding portion and a connecting portion, the connecting portion being used to connect the protruding portion to the terminal body, and the projection of the connecting portion in the thickness direction of the wall portion is located between the outer circumferential surface of the terminal body and the hole wall of the electrode lead-out hole. A thin portion is provided in the connecting portion.

[0028] When the internal pressure or temperature of the outer casing reaches a threshold, the protrusion can be reversed along with the curvature of the weakened section, thereby releasing the wall and being pulled out through the electrode exit hole. By providing the weakened section at the connection point, the limitations on the strength of the protrusion are relaxed, and the shape design of the protrusion is made more flexible.

[0029] In some embodiments, shallow grooves are provided in the electrode terminals, and the thin portion is formed at the bottom of the shallow grooves. By forming the thin portion by creating shallow grooves, the molding efficiency of the electrode terminals can be improved.

[0030] In some embodiments, the shallow groove is provided on the surface facing the wall of the first stopper portion.

[0031] In some embodiments, the shallow groove is located on the surface opposite to the wall of the first stopper section. When the internal pressure or temperature of the outer casing reaches a threshold, the shallow groove provides space for the material to flow, helping to curve the first stopper section.

[0032] In some embodiments, the electrode terminals are provided with recesses. The recesses are recessed along the thickness direction of the wall, extending from the inside of the outer case to the outside of the outer case, and at least a portion of the recess is provided on the side facing the tab of the terminal body.

[0033] When the internal pressure or temperature of the outer case reaches a threshold, the first stopper portion is bent, and the recess can provide space for the material to flow during the bending process of the first stopper portion, thereby reducing the resistance of the first stopper portion to bending and allowing the first stopper portion to be immediately pulled out from the electrode extraction hole.

[0034] In some embodiments, the recess includes a first side and a second side, the first side being provided along the radially outer side of the electrode extraction hole of the second side, the first side being connected to the bottom surface of the recess and being positioned at an angle toward the side away from the central axis of the electrode terminal.

[0035] By installing the first side at an angle, more space can be provided for the material to flow when the first stopper is bent, and the resistance of the first stopper to bending can be reduced.

[0036] In some embodiments, the recess includes a first side and a second side, the first side being provided along the radially outer side of the electrode extraction hole of the second side, and the second side being connected to the bottom surface of the recess and positioned at an angle toward the side closer to the central axis of the electrode terminal.

[0037] By installing the second side at an angle, the risk of interference between the second and first sides when the first side deforms due to material flow is reduced, thereby decreasing the resistance of the first stopper portion to bending.

[0038] In some embodiments, the first stopper portion is bendable toward the recess when the internal pressure or temperature of the outer case reaches a threshold.

[0039] When the internal pressure or temperature of the outer case reaches a threshold, the first stopper portion curves toward the recess, causing the material to flow toward the recess, reducing the bending resistance of the first stopper portion, and allowing the first stopper portion to be immediately pulled out from the electrode extraction hole.

[0040] In some embodiments, the first stopper portion is formed by folding back a portion of the electrode terminal.

[0041] During assembly, the electrode terminals can be inserted into the outer case through the electrode exit holes, and then a portion of the electrode terminals is folded back to form a first stopper portion, thereby securing the electrode terminals to the wall.

[0042] In some embodiments, the terminal body includes a terminal projection, and the recess is located around the terminal projection. In the thickness direction of the wall, the end face of the terminal projection facing the tab is closer to the tab than the first stopper portion.

[0043] The first stopper portion is less likely to interfere with the contact between the terminal protrusion and other components, thereby reducing excessive positioning and lowering the risk of poor contact between the terminal protrusion and other components due to the unevenness of the first stopper portion, thereby improving the current flow capability and reliability of the battery cell.

[0044] In some embodiments, the electrode terminal further includes a second stopper portion, which protrudes from the outer circumferential surface of the terminal body and is located outside the wall portion. In the thickness direction of the wall portion, at least a portion of the wall portion is located between the protruding portion and the second stopper portion. The wall portion is positioned between the first stopper portion and the second stopper portion, thereby restricting relative movement between the electrode terminal and the wall portion.

[0045] In some embodiments, in the radial direction of the electrode extraction hole, the end of the second stopper portion away from the terminal body extends beyond the end of the first stopper portion away from the terminal body.

[0046] In the radial direction of the electrode lead-out hole, the second stopper portion has a larger dimension than the first stopper portion, thereby increasing the exposed area of ​​the electrode terminals, facilitating connection between the electrode terminals and the external bus component, increasing the connection area between the electrode terminals and the bus component, and improving current flow capability. In the radial direction of the electrode lead-out hole, the first stopper portion has a larger dimension than the second stopper portion, thereby making it easier to deform when the internal pressure or temperature of the outer case reaches a threshold, allowing for immediate pressure reduction and improving the reliability of the battery cell.

[0047] In some embodiments, the first stopper portion, the second stopper portion, and the terminal body are integrally molded, which improves the overall structural strength of the electrode terminal, reduces the internal resistance of the low electrode terminal, and improves the current passage capability.

[0048] In some embodiments, the battery cell further includes a sealing member, at least a portion of which is provided between the first stopper portion and the wall portion. The sealing member can fill the gap between the first stopper portion and the wall portion, thereby sealing the electrode extraction hole.

[0049] In some embodiments, the melting point of the electrode terminals is lower than that of the wall. When phenomena such as short circuits or overcharging occur, the internal temperature of the outer case rises rapidly. The electrode terminals have a lower melting point than the wall, which allows the electrode terminals to melt or soften before the wall, helping to achieve directional pressure reduction of the battery cell.

[0050] In some examples, if the melting point of the electrode terminal is H1 and the melting point of the wall is H2, then H2 - H1 ≥ 300°C.

[0051] When phenomena such as short circuits or overcharging occur, the internal temperature of the outer casing becomes uneven. However, the above technical solution has a large difference between the melting point of the electrode terminals and the melting point of the wall, which reduces the risk that the wall will melt before the electrode terminals due to the uneven internal temperature, thereby improving the reliability of the battery cell.

[0052] In some embodiments, the material of the electrode terminals includes aluminum or copper, and the material of the wall includes steel.

[0053] By using steel as the main material for the wall, the wall can have good mechanical strength and heat resistance, reducing the risk of the wall melting and rupturing when the battery cell experiences thermal runaway. The electrode terminals have a low melting point, making them more easily softened and deformed when the battery cell experiences thermal runaway. This allows the internal and external spaces of the outer casing to immediately communicate through the electrode exit holes, reducing the risk of explosion and improving the reliability of the battery cell.

[0054] In some embodiments, the outer case includes a housing and an end cover, one end of the housing having an opening, the end cover fitting over the opening, the housing includes a side wall and an end wall, the side wall enclosing the outside of the electrode assembly, the end wall positioned opposite the opening, and the wall portion is the end cover or end wall.

[0055] The end cover or end wall is flatter than the side wall, and the placement of the electrode terminals on the end cover or end wall can improve the assembly efficiency of the battery cell.

[0056] In some embodiments, the projection of the wall along its own thickness direction is rectangular or annular.

[0057] According to a second aspect, the present application provides a battery comprising a plurality of battery cells relating to any embodiment of the first aspect.

[0058] According to a third aspect, the present application provides a power consumption device including a battery according to a second aspect for supplying electrical energy. [Brief explanation of the drawing]

[0059] The features, advantages, and technical effects of exemplary embodiments of the present application will be described below with reference to the drawings.

[0060] [Figure 1] This is a schematic diagram of the structure of a vehicle according to several embodiments of the present invention. [Figure 2] This is a schematic diagram of the disassembled battery according to some embodiments of the present invention. [Figure 3] Figure 2 is a schematic diagram of the battery module's structure. [Figure 4] This is a schematic diagram of the structure of a battery cell according to several embodiments of the present invention. [Figure 5] Figure 4 is a schematic cross-sectional view of the battery cell. [Figure 6] This is a magnified schematic diagram of the area enclosed by the circle in Figure 5. [Figure 7] This is a schematic diagram of a local cross-section of a battery cell housing according to some embodiments of the present application. [Figure 8] This is a schematic cross-sectional view of the electrode terminals of a battery cell according to some embodiments of the present invention. [Figure 9] This is a schematic diagram of a local cross-section of a battery cell according to some embodiments of the present application. [Figure 10] Figure 9 is a schematic diagram of the electrode terminals. [Figure 11] This is a schematic cross-sectional view of the electrode terminals of a battery cell according to another embodiment of the present invention. [Figure 12] This is a schematic diagram of a local cross-section of a battery cell according to some embodiments of the present application. [Figure 13] Figure 12 is a schematic cross-sectional view of the electrode terminals. [Figure 14] This is a schematic cross-sectional view of the electrode terminals of a battery cell according to another embodiment of the present invention. [Figure 15] This is a schematic diagram of a local cross-section of a battery cell according to another embodiment of the present invention. [Figure 16] Figure 15 is a schematic cross-sectional view of the electrode terminals. [Figure 17]This is a schematic diagram of the three-dimensional structure of a battery cell according to another embodiment of the present invention.

[0061] In drawings, the drawings are not drawn according to actual proportions. [Modes for carrying out the invention]

[0062] To further clarify the purpose, technical solutions, and advantages of the embodiments of this application, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the drawings of the embodiments. Clearly, the embodiments described are some, but not all, embodiments of this application. All other embodiments obtained by a person skilled in the art without requiring any creative effort based on the embodiments of this application are all within the scope of protection of this application.

[0063] Unless otherwise defined, all technical and scientific terms used in this Application have the same meaning as that commonly understood by those skilled in the art relating to the Application. In this Application, terms used in the Specification are solely for the purpose of describing specific embodiments and are not intended to limit the Application. The terms “includes” and “have,” and any variations thereof, in the Specification, Claims, and Brief Description of the Drawings, are intended to intentionally cover non-exclusive “includes.” Terms such as “first,” “second,” etc., in the Specification, Claims, or Drawings are not intended to describe a specific order or hierarchical relationship, but rather to distinguish between different subjects.

[0064] The “Examples” as used herein mean that certain features, structures, or properties described in conjunction with the Examples may be included in at least one Example of this Application. Where the term “Examples” appears elsewhere in this Specification, it does not necessarily refer to the same Example, nor does it refer to an Example that is mutually exclusive, independent, or substitutable with the other Examples.

[0065] In the description of this application, unless otherwise specifically defined and limited, the terms “attach,” “connect,” “connection,” and “attach” should be understood in a broad sense, for example, a fixed connection, a removable connection, or an integral connection. They may be directly connected, indirectly connected via an intermediate medium, or internally connected between two elements. A person skilled in the art will be able to understand the specific meaning of these terms in this application depending on the specific circumstances.

[0066] In this application, the terms "and / or" merely describe the relationship between related objects and indicate that three relationships may exist. For example, A and / or B may represent three cases: A alone, A and B as a combination, or B alone. In addition, the character " / " in this application generally indicates that the preceding and succeeding related objects are in an "or" relationship.

[0067] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the dimensions such as thickness, length, and width of various components in the embodiments of this application shown in the drawings, and the overall dimensions such as thickness, length, and width of the integrating device, are illustrative and should not constitute any limitation to this application.

[0068] The term "multiple" as used in this application refers to two or more (including two).

[0069] In the embodiments of the present invention, the battery cell may be a secondary battery, which refers to a battery cell that can continue to be used by activating the active material through charging after the battery cell has been discharged.

[0070] The battery cell may be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and is not limited to these in the embodiments of this application.

[0071] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and an isolation member. During the charging and discharging process of the battery cell, active ions (e.g., lithium ions) move back and forth between the positive and negative electrodes, undergoing intercalation and deintercalation. The isolation member is placed between the positive and negative electrodes and serves to prevent short circuits between them while allowing active ions to pass through.

[0072] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material placed on at least one surface of the positive electrode current collector.

[0073] For example, the positive electrode current collector has two surfaces that are opposite to each other in the thickness direction of itself, and the positive electrode active material is placed on one or both of the two opposite surfaces of the positive electrode current collector.

[0074] As an example, the positive electrode current collector may be a metal foil sheet or a composite current collector. For example, as the metal foil sheet, aluminum or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, graphite electrodes, carbon, nickel, or titanium may be used. The composite current collector may include a polymer substrate 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, and silver alloy) on a polymer material substrate (for example, a substrate such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0075] As an example, the positive electrode active material may include at least one material among lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone, or two or more of them may be used in combination. As the lithium-containing phosphate, for example, at least one of lithium iron phosphate (e.g., LiFePO4 (also called LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as 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 may be included, but not limited thereto. As an example of the lithium transition metal oxide, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4, etc.), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also called NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also called NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also called NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also called NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also called NCM 811 ), lithium nickel cobalt aluminum oxide (LiNi 0.80 Co 0.15 Al 0.05 O2, etc.) and at least one of their modified compounds may be included, but not limited thereto.

[0076] In some embodiments, a foamed metal may be used as the positive electrode. The foamed metal may be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon. When a foamed metal is used as the positive electrode, the positive electrode active material may or may not be placed on the surface of the foamed metal. As an example, a lithium source material, potassium metal, or sodium metal may be filled and / or deposited within the foamed metal, and the lithium source material is lithium metal and / or a lithium-rich material.

[0077] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0078] As an example, the negative electrode current collector can be a metal foil, foamed metal, or a composite current collector. For example, as the metal foil, silver-surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium can be used. The foamed metal may be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon. The composite current collector may include a polymer substrate layer and a metal layer. The composite current collector can be formed by forming a metal material (such as copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys) on a polymer material substrate (for example, a substrate such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0079] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material placed on at least one surface of the negative electrode current collector.

[0080] For example, the negative electrode current collector has two opposing surfaces in the thickness direction of itself, and the negative electrode active material is provided on one or both of the two opposing surfaces of the negative electrode current collector.

[0081] As an example, the negative electrode active material can be any 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, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide, silicon-carbon composite, silicon-nitrogen composite, and silicon alloy. The tin-based material may be selected from at least one of elemental tin, tin oxide, and tin alloy. However, this application is not limited to these materials, and other conventional materials that can be used as battery negative electrode active materials may also be used. These negative electrode active materials may be used individually or in combination of two or more types.

[0082] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0083] In some embodiments, the electrode assembly further includes an isolation member placed between the positive and negative electrodes.

[0084] In some embodiments, the separating member is a separator. The present application does not particularly limit the type of separator, and any well-known porous separator with good chemical and mechanical stability may be selected.

[0085] As an 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 thin film or a multilayer composite thin film, and there are no particular restrictions. If the separator is a multilayer composite thin film, the materials of each layer may be the same or different, and there are no particular restrictions. The isolation member may be positioned between the positive and negative electrodes as a single member, or it may be attached to the surfaces of the positive and negative electrodes.

[0086] In some embodiments, the isolation member is a solid electrolyte. The solid electrolyte is placed between the positive and negative electrodes and simultaneously transmits ions, thereby isolating the positive and negative electrodes.

[0087] In some embodiments, the battery cell further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The present application does not particularly limit the type of electrolyte, which can be selected as needed. The electrolyte may be liquid, gel-like, or solid.

[0088] Here, the liquid electrolyte includes an electrolyte salt and a solvent.

[0089] 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.

[0090] 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 is selectively an ether-based solvent. 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, methyltetrahydrofuran, diphenyl ether, and crown ether.

[0091] Here, the gel-like electrolyte contains a polymer-based skeletal network and is combined with an ionic liquid-lithium salt.

[0092] Here, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0093] As an example, the polymer solid electrolyte may be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymer, polyionic liquid lithium salt, cellulose, etc.

[0094] As an example, the inorganic solid electrolyte may be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superionic conductor (lithium germanium phosphate sulfur, silver sulfur germanium ore), amorphous sulfide), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0095] As an example, a composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0096] In some embodiments, the electrode assembly has a wound structure. The positive electrode sheet and the negative electrode sheet are wound together to form a wound structure.

[0097] In some embodiments, the electrode assembly has a layered structure.

[0098] For example, multiple positive electrode sheets and multiple negative electrode sheets may be installed, and the multiple positive electrode sheets and multiple negative electrode sheets may be stacked alternately.

[0099] For example, multiple positive electrode sheets may be installed, and the negative electrode plates may be folded to form multiple folded segments that are stacked and installed, with one positive electrode sheet sandwiched between adjacent folded segments.

[0100] For example, both the positive electrode sheet and the negative electrode plate are folded and stacked to form multiple folded segments.

[0101] For example, multiple separators may be installed, each placed between any adjacent positive electrode sheets or negative electrode plates.

[0102] For example, the isolation members may be installed in a continuous manner, and may be installed between any adjacent positive or negative electrode sheets by folding or rolling them up.

[0103] In some embodiments, the shape of the electrode assembly may be cylindrical, flattened, or polygonal prism-shaped, etc.

[0104] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn out of the electrode assembly. The tabs include a positive electrode tab and a negative electrode tab.

[0105] In some embodiments, the battery cell may include an outer case. The outer case is for packaging components such as electrode assemblies and electrolytes. The outer case may be a steel case, an aluminum case, a plastic case (e.g., polypropylene), a composite metal case (e.g., a copper-aluminum composite outer case), or an aluminum-plastic film, etc.

[0106] For example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft pack battery cell, or a battery cell of other shape. A prismatic battery cell includes a rectangular battery cell, a blade-shaped battery cell, and a polygonal prismatic battery, and a polygonal prismatic battery is a hexagonal prismatic battery, etc., and this application is not particularly limited.

[0107] The batteries referred to in the embodiments of this application refer to a single physical module comprising one or more battery cells to provide higher voltage and capacity.

[0108] In some embodiments, the battery may be a battery module, and if there are multiple battery cells, the multiple battery cells are arranged and fixed to form a single battery module.

[0109] In some embodiments, the battery may be a battery pack, which includes a housing and battery cells, and the battery cells or battery modules are housed in the housing.

[0110] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, part of the housing may be at least part of the vehicle's floor, or part of the housing may be at least part of the vehicle's crossbeams and longitudinal beams.

[0111] In some embodiments, the battery may be an energy storage device. The energy storage device includes energy storage containers, energy storage cabinets, and the like.

[0112] In some embodiments, the battery cell generally includes an electrode assembly, electrode terminals, and an outer casing. The electrode assembly is electrically connected to the outside via the electrode terminals. The outer casing can house the electrode assembly and also forms a support for the electrode assembly.

[0113] If phenomena such as short circuits or overcharging occur, thermal runaway can occur inside the battery cell, causing a rapid increase in internal pressure within the outer casing and creating a risk of the battery cell exploding.

[0114] Considering the above, the embodiment of the present invention provides a battery cell that, when the internal pressure or temperature of the outer case reaches a threshold, utilizes the deformation of the electrode terminals to connect the internal and external spaces of the outer case, thereby releasing the internal pressure of the battery cell and reducing the risk of the battery cell exploding. Compared to means in which a depressurization mechanism is additionally installed in the outer case, the present invention can simplify the structure of the battery cell.

[0115] The battery cell described in the embodiment of this application is applicable to batteries and power consumption devices that use batteries.

[0116] The battery cells, batteries, and power consumption devices disclosed in the embodiments of this application can be used in power consumption devices that use batteries as a power source or in various energy storage systems that use batteries as energy storage elements. Power consumption devices may include, but are not limited to, mobile phones, tablets, laptop computers, electric toys, power tools, battery cars, electric vehicles, ships, and spacecraft. Electric toys may include stationary or mobile electric toys such as game consoles, electric car toys, electric boat toys, and electric aircraft toys, and spacecraft may include aircraft, rockets, space shuttles, and spacecraft.

[0117] For the sake of explanation, the following embodiments will use a vehicle as an example of a power consumption device.

[0118] Figure 1 is a schematic diagram of the structure of a vehicle according to several embodiments of the present invention.

[0119] As shown in Figure 1, a battery 2 is installed inside the vehicle 1, and the battery 2 may be installed at the bottom, front, or rear of the vehicle 1. The battery 2 can be used to supply power to the vehicle 1, and can be used, for example, as the operating power source for the vehicle 1.

[0120] Vehicle 1 may further include a controller 3 and a motor 4, the controller 3 being used to control the battery 2 to supply power to the motor 4, for example, to meet the power requirements for starting, navigating, and driving Vehicle 1.

[0121] In some embodiments of the present invention, the battery 2 can provide driving power to the vehicle 1 not only as an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, by substituting for or partially substituting for fuel or natural gas.

[0122] Figure 2 is a schematic exploded view of a battery according to some embodiments of the present invention. As shown in Figure 2, the battery 2 includes a housing 5 and battery cells (not shown in Figure 2), the battery cells being housed within the housing 5.

[0123] The housing 5 is used to house battery cells, and the housing 5 may have various structures. In some embodiments, the housing 5 may include a first housing portion 5a and a second housing portion 5b, the first housing portion 5a and the second housing portion 5b overlap each other, and both the first housing portion 5a and the second housing portion 5b define a housing space 5c for housing battery cells. The second housing portion 5b may be a hollow structure with one end open, and the first housing portion 5a is a plate-like structure, with the first housing portion 5a overlapping the open side of the second housing portion 5b, thereby forming a housing 5 having a housing space 5c. Both the first housing portion 5a and the second housing portion 5b may be hollow structures with one side open, with the open side of the first housing portion 5a overlapping the open side of the second housing portion 5b, thereby forming a housing 5 having a housing space 5c. The first housing portion 5a and the second housing portion 5b may have various shapes such as cylinders and rectangular parallelepipeds.

[0124] To improve the airtightness after connecting the first housing section 5a and the second housing section 5b, sealing members such as sealing material and sealing rings may be installed between the first housing section 5a and the second housing section 5b.

[0125] When the first housing section 5a is placed over the upper part of the second housing section 5b, the first housing section 5a can be called the upper housing cover, and the second housing section 5b can be called the lower housing.

[0126] In battery 2, there may be one battery cell or multiple battery cells. If there are multiple battery cells, they can be connected in series, in parallel, or in series-parallel. Series-parallel connection means that there are not only series connections but also parallel connections between the multiple battery cells. Multiple battery cells can be directly connected in series, in parallel, or in series-parallel, and then the entire assembly composed of multiple battery cells can be housed in the housing 5. Naturally, multiple battery cells may first be connected in series, in parallel, or in series-parallel to form a battery module 6, and then the multiple battery modules 6 may be further connected in series, in parallel, or in series-parallel to form a single unit which can then be housed in the housing 5.

[0127] A battery cell may be the smallest unit that makes up a battery.

[0128] Figure 3 is a schematic diagram of the battery module structure shown in Figure 2.

[0129] In some embodiments, as shown in Figure 3, there are multiple battery cells 7, and these multiple battery cells 7 are first connected in series, in parallel, or in series-parallel to form a battery module 6. These multiple battery modules 6 may be further connected in series, in parallel, or in series-parallel to form a single unit and housed within a housing.

[0130] Multiple battery cells 7 in the battery module 6 may be electrically connected by bus members, thereby realizing series connection, parallel connection, or series-parallel connection of multiple battery cells 7 in the battery module 6. There may be one or more bus members, and each bus member is used to electrically connect at least two battery cells.

[0131] Figure 4 is a schematic diagram of the structure of a battery cell according to some embodiments of the present application, Figure 5 is a schematic cross-sectional view of the battery cell shown in Figure 4, Figure 6 is an enlarged schematic view of the area circled in Figure 5, Figure 7 is a schematic local cross-sectional view of the housing of a battery cell according to some embodiments of the present application, and Figure 8 is a schematic cross-sectional view of the electrode terminals of a battery cell according to some embodiments of the present application.

[0132] As shown in Figures 4 to 8, the embodiment of the present invention provides a battery cell 7 including an outer case 20, an electrode assembly 10, and other functional members (for example, electrode terminals 30 installed on the outer case 20), wherein at least a portion of the electrode assembly 10 is housed within the outer case 20.

[0133] The outer case 20 has a hollow structure, and an internal space is formed to house the electrode assembly 10 and the electrolyte. The shape of the outer case 20 is determined by the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 has a rectangular parallelepiped structure, a rectangular outer case can be selected, and if the electrode assembly 10 has a cylindrical structure, a cylindrical outer case can be selected.

[0134] For example, the outer case 20 includes a housing 21 and an end cover 22, the housing 21 having an opening, and the end cover 22 fitting over the opening.

[0135] The housing 21 is an assembly that fits with the end cover 22 to form the internal cavity of the battery cell 7, and the formed internal cavity can be used to house the electrode assembly 10, electrolyte and other components.

[0136] The housing 21 and the end cover 22 may be separate components. For example, an opening may be provided in the housing 21, and the end cover 22 may be placed over the opening to form the internal cavity of the battery cell 7.

[0137] The housing 21 may have various shapes and dimensions, such as a rectangular prism, cylinder, or hexagonal prism. Specifically, the shape of the housing 21 is determined by the specific shape and size of the electrode assembly 10. The housing 21 may be made of any material, such as copper, iron, aluminum, stainless steel, or aluminum alloy, and the embodiments of this application are not particularly limited to these materials.

[0138] The shape of the end cover 22 can be adapted to the shape of the housing 21 so that it can be fitted into the housing 21. The material of the end cover 22 may be the same as or different from the material of the housing 21. Preferably, the end cover 22 can be manufactured from a material having a certain hardness and strength (for example, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.), so that the end cover 22 is less likely to deform even if it is pressed or struck, the battery cell 7 can have higher structural strength and improved reliability.

[0139] The end cover 22 is connected to the housing 21 by welding, bonding, fastening, or other means.

[0140] The housing 21 may have an open end or both ends. In some examples, the housing 21 may have a structure with one side open, and one end cover 22 is installed and placed over the housing 21. In another example, the housing 21 may have a structure with both sides open, and two end covers 22 are installed, with each of the two end covers 22 placing over the two openings of the housing 21.

[0141] The electrode terminals 30 can be used to electrically connect to the electrode assembly 10 and are used to output or input electrical energy from the battery cell 7.

[0142] The electrode assembly 10 is a component that generates an electrochemical reaction in the battery cell 7. One or more electrode assemblies 10 can be included in the housing 21.

[0143] As an example, the electrode assembly 10 includes a positive electrode sheet and a negative electrode sheet. The portions of the positive electrode sheet and the negative electrode sheet containing the active material constitute the main body of the electrode assembly 10, while the portions of the positive electrode sheet and the negative electrode sheet not containing the active material each constitute a tab. The tab may include a positive electrode tab and a negative electrode tab. The positive electrode tab and the negative electrode tab may be located together at one end of the main body, or they may be located at both ends of the main body, respectively.

[0144] During the charging and discharging process of the battery, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs are connected to the electrode terminals 30 to form an electric current circuit.

[0145] In some embodiments, the battery cell 7 includes an outer case 20, an electrode assembly 10, and electrode terminals 30. The outer case 20 includes a wall portion 23, the wall portion 23 of which is provided with an electrode exit hole 231. At least a portion of the electrode assembly 10 is housed within the outer case 20, and the electrode assembly 10 includes a tab 11. The electrode terminals 30 are installed in the wall portion 23 and cover at least a portion of the electrode exit hole 231, and the electrode terminals 30 are electrically connected to the tab 11. At least a portion of the electrode terminals 30 is deformable when the internal pressure or temperature of the outer case 20 reaches a threshold, thereby allowing the internal and external spaces of the outer case 20 to communicate through the electrode exit hole 231 and to expel gas from inside the outer case 20.

[0146] For example, the wall portion 23 may be an end cover 22, or it may be one of the walls of the housing 21.

[0147] For example, the shape of the wall portion 23 may be circular, rectangular, elliptical, or other shapes.

[0148] Exemplary, the electrode exit hole 231 penetrates the wall 23, thereby facilitating the electrode terminal 30 to draw electrical energy from the electrode assembly 10 to the outside of the outer case 20. Selectively, the electrode exit hole 231 penetrates the wall 23 along the thickness direction Z of the wall 23.

[0149] The tab 11 electrically connected to the electrode terminal 30 may be a positive electrode tab or a negative electrode tab.

[0150] The tab 11 may be directly connected to the electrode terminal 30, for example by welding, contact, or other means. Alternatively, the tab 11 may be indirectly connected to the electrode terminal 30 via another conductive member (e.g., a current collector 40), thereby achieving an electrical connection between the tab 11 and the electrode terminal 30.

[0151] The material of the electrode terminal 30 may be the same as or different from the material of the wall portion 23. For example, different materials can be used for the electrode terminal 30 and the wall portion 23, and the melting point of the electrode terminal 30 may be the same as or different from the melting point of the wall portion 23.

[0152] The electrode terminal 30 may cover only a portion of the electrode lead hole 231, or it may completely cover the electrode lead hole 231. For example, the electrode terminal 30 can seal the electrode lead hole 231 on its own, isolating the internal space of the outer case 20 from the external space and improving the sealing performance of the battery cell 7. Alternatively, the electrode terminal 30 can be combined with other functional members (e.g., sealing member 50) to jointly seal the electrode lead hole 231, isolating the internal space of the outer case 20 from the external space and improving the sealing performance of the battery cell 7.

[0153] The design of the threshold varies depending on the design requirements. The threshold may depend on one or more materials among the positive electrode, negative electrode, electrolyte, and isolation member in the battery cell 7.

[0154] When the internal pressure or temperature of the outer case 20 reaches a threshold, deformation of the electrode terminals 30 may include, but is not limited to, bending, rupture, shrinkage, melting, etc.

[0155] When phenomena such as short circuits or overcharging occur, the electrolyte and active material react, releasing gas and heat.

[0156] In the embodiment of the present invention, deformation of the electrode terminal 30 may be triggered by the internal pressure of the outer case 20 alone, or by the internal temperature of the outer case 20 alone, or by a combination of the internal pressure and internal temperature of the outer case 20.

[0157] For example, as gas continuously accumulates inside the outer case 20, the internal pressure of the outer case 20 will reach and even exceed a pressure threshold. When the internal pressure of the outer case 20 reaches the threshold, the electrode terminals 30 deform under the action of the internal pressure, thereby connecting the internal and external spaces of the outer case 20 through the electrode exit holes 231. The gas inside the outer case 20 is then released through the electrode exit holes 231, reducing the risk of the battery cell 7 exploding.

[0158] For example, when the electrolyte and active material react and heat is rapidly released, it causes an increase in the internal temperature of the outer case 20, and this increase in temperature also causes an increase in the internal pressure of the outer case 20. When the internal temperature of the outer case 20 reaches a threshold, the electrode terminals 30 deform under the action of temperature and pressure, thereby connecting the internal and external spaces of the outer case 20 through the electrode exit holes 231, and the gas inside the outer case 20 is discharged through the electrode exit holes 231, reducing the risk of the battery cell 7 exploding.

[0159] When the internal pressure or temperature of the outer case 20 reaches a threshold, the embodiment of the present invention utilizes the deformation of the electrode terminals 30 to connect the internal space of the outer case 20 with the external space, thereby releasing the internal gas and internal pressure of the outer case 20 and reducing the risk of the battery cell 7 exploding. Compared to means in which a depressurization mechanism is additionally installed in the outer case 20, the embodiment of the present invention simplifies the structure of the battery cell 7 and reduces the cost of the battery cell.

[0160] In some embodiments, at least a portion of the electrode terminals 30 can detach from the wall portion 23 when the internal pressure or temperature of the outer case 20 reaches a threshold.

[0161] In the case of the electrode terminal 30, if the internal pressure or temperature of the outer case 20 reaches a threshold, the electrode terminal 30 may detach entirely from the wall portion 23, or only a portion of it may detach from the wall portion 23.

[0162] The statement that at least a portion of the electrode terminal 30 is detached from the wall portion 23 means that at least a portion of the electrode terminal 30 may be displaced from its initial set position without being constrained by the wall portion 23.

[0163] When at least a portion of the electrode terminal 30 detaches from the wall portion 23, at least a portion of the electrode exit hole 231 is no longer covered by the electrode terminal 30, allowing the electrode exit hole 231 to communicate with the internal and external spaces of the outer case 20. This releases the internal gas of the battery cell 7, reducing the internal pressure and temperature of the battery cell 7.

[0164] In some embodiments, the electrode terminal 30 can be completely detached from the wall portion 23 when the internal pressure or temperature of the outer case 20 reaches a threshold.

[0165] When phenomena such as short circuits or overcharging occur, the electrode terminals 30 can detach from the wall portion 23, thereby preventing the electrode lead-out holes 231 from being blocked by the electrode terminals 30. This increases the gas release rate and reduces the risk of the battery cell 7 exploding.

[0166] In some embodiments, the outer case 20 includes a housing 21 and an end cover 22, with one end of the housing 21 having an opening and the end cover 22 fitting over the opening. The housing 21 includes a side wall 212 and an end wall 211, with the side wall 212 surrounding the outside of the electrode assembly 10 and the end wall 211 positioned opposite the opening, and the wall portion 23 being either the end cover 22 or the end wall 211.

[0167] The side wall 212 may be one or more. In some examples, the side wall 212 may be one and have a cylindrical structure. In other examples, the side wall 212 may be multiple and connected sequentially along the circumferential direction of the electrode assembly 10, for example, there may be four side walls 212, which are connected sequentially to form a prismatic structure.

[0168] In some embodiments, the battery cell 7 is a cylindrical battery cell, with one side wall 212 exhibiting a cylindrical structure. The assembly efficiency of the battery cell 7 can be improved by having an end cover 22 or end wall 211 that is flatter than the side wall 212, and by having the electrode terminals 30 installed on the end cover 22 or end wall 211.

[0169] In some embodiments, the housing 21 is a one-piece molded structure, and the wall portion 23 is an end wall 211.

[0170] In some embodiments, the melting point of the electrode terminal 30 is lower than the melting point of the wall portion 23.

[0171] When phenomena such as short circuits or overcharging occur, the internal temperature of the outer case 20 rises rapidly. The electrode terminals 30 have a lower melting point than the wall portion 23, which allows the electrode terminals 30 to melt or soften before the wall portion 23, thus helping to achieve directional pressure reduction of the battery cell 7.

[0172] Furthermore, when welding the electrode terminal 30 to other components, the low melting point of the electrode terminal 30 material is advantageous in lowering the welding temperature, and the relatively high melting point of the wall portion 23 material can reduce the adverse effects of the welding process on the wall portion 23, thereby reducing the risk of electrolyte leakage.

[0173] In some embodiments, if the melting point of the electrode terminal 30 is H1 and the melting point of the wall portion 23 is H2, then H2 - H1 ≥ 300°C.

[0174] When phenomena such as short circuits or overcharging occur, the internal temperature of the outer case 20 becomes uneven. However, in the embodiment of the present invention, there is a large difference between the melting point of the electrode terminals 30 and the melting point of the wall portion 23. Therefore, the risk of the wall portion 23 melting before the electrode terminals 30 due to uneven internal temperature can be reduced, thereby improving the reliability of the battery cell 7.

[0175] Selectively, H2-H1 ≥ 500℃.

[0176] In some embodiments, the material of the electrode terminal 30 includes aluminum or copper, and the material of the wall portion 23 includes steel. For example, the material of the wall portion 23 may be stainless steel, nickel-plated steel, or other materials mainly composed of steel.

[0177] By using steel as the main material for the wall portion 23, the wall portion 23 can have good mechanical strength and heat resistance, reducing the risk of the wall portion 23 melting and rupturing when the battery cell 7 experiences thermal runaway. The material of the electrode terminals 30 has a low melting point, so when the battery cell 7 experiences thermal runaway, the electrode terminals 30 soften and deform more easily, thereby immediately connecting the internal and external spaces of the outer case 20 through the electrode exit holes 231, reducing the risk of explosion and improving the reliability of the battery cell 7.

[0178] In some embodiments, the battery cell 7 further includes a current collector 40, which is connected to electrode terminals 30 and tabs 11. Selectively, when the internal pressure or temperature of the outer case 20 reaches a threshold, the electrode terminals 30 are disconnected from the current collector 40 and detached from the wall 23.

[0179] In some embodiments, the current collector 40 may be connected to the tab 11 by welding, abutment, adhesive or other means, and an electrical connection between the electrode terminal 30 and the tab 11 is achieved by connecting to the electrode terminal 30 by welding, abutment, adhesive or other means.

[0180] The current collector 40 is made of a conductive material; for example, the current collector 40 is made of a conductive metal.

[0181] In some embodiments, the surface of the current collector 40 opposite to the wall portion 23 abuts against the tab 11, and the surface of the current collector 40 facing the wall portion 23 abuts against the electrode terminal 30.

[0182] In some embodiments, the current collector 40 is welded to the tab 11. For example, the current collector 40 is connected to the tab 11 by ultrasonic welding, laser welding, or other welding methods.

[0183] In some embodiments, the main material of the current collector 40 is the same as the main material of the tab 11.

[0184] In some examples, the main material of the current collector 40 is aluminum, and the main material of the tab 11 is aluminum. For example, the material of the current collector 40 is an aluminum alloy, and the material of the tab 11 is aluminum foil.

[0185] In another example, the main material of the current collector 40 is copper, and the main material of the tab 11 is copper. For example, the material of the current collector 40 is a copper alloy, and the material of the tab 11 is copper foil. The main material of the current collector 40 is the same as the main material of the tab 11, which can improve the welding strength between the current collector 40 and the tab 11, reduce resistance, and improve current transmission capability.

[0186] In some embodiments, the current collector 40 is welded to the electrode terminal 30. For example, the current collector 40 is connected to the electrode terminal 30 by laser welding, resistance welding, ultrasonic welding, or other welding methods.

[0187] In some embodiments, the main material of the current collector 40 is the same as the main material of the electrode terminal 30.

[0188] In some examples, the main material of the current collector 40 is aluminum, and the main material of the electrode terminal 30 is aluminum. For example, both the electrode terminal 30 and the current collector 40 are made of aluminum alloy.

[0189] In another example, the main material of the current collector 40 is copper, and the main material of the electrode terminal 30 is copper. For example, both the electrode terminal 30 and the current collector 40 are made of a copper alloy.

[0190] In some embodiments, when the internal temperature of the outer case 20 reaches a threshold, the strength of the weld between the electrode terminal 30 and the current collector 40 decreases, and under the action of the internal pressure of the outer case 20, a crack occurs between the electrode terminal 30 and the current collector 40, releasing the electrode terminal 30 from its restraint by the current collector 40, and allowing the electrode terminal 30 to detach from the wall portion 23.

[0191] In some embodiments, if the internal pressure or temperature of the outer case 20 reaches a threshold, the weld between the electrode terminal 30 and the current collector 40 may crack, but the weld between the tab 11 and the current collector 40 maintains a fixed connection between the tab 11 and the current collector 40, thereby reducing the risk of the current collector 40 clogging the electrode lead hole 231.

[0192] In some embodiments, the electrode terminal 30 includes a projection 311 that protrudes radially from the electrode exit hole 231a of the electrode exit hole 231, and the projection 311 is located on the side of the wall 23 facing the electrode assembly 10.

[0193] The radial direction of the electrode extraction hole 231 may pass through the central axis X of the electrode extraction hole 231 and be perpendicular to the central axis X of the electrode extraction hole 231. Selectively, the central axis X of the electrode extraction hole 231 is parallel to the thickness direction Z of the wall portion 23.

[0194] The central axis X of the electrode extraction hole 231 is a hypothetical line. For example, the electrode extraction hole 231 is rotationally symmetric with respect to the central axis.

[0195] In some examples, the electrode extraction hole 231 may be a circular hole, and the radial direction of the electrode extraction hole 231 may be the radial direction of the electrode extraction hole 231. In other examples, the electrode extraction hole 231 may be a square hole, and the radial direction of the electrode extraction hole 231 may be the radial direction of the circumscribed circle of the electrode extraction hole 231.

[0196] The statement that the protruding portion 311 protrudes from the hole wall 231a of the electrode extraction hole 231 may mean that, in the thickness direction Z of the wall portion 23, the projection of the protruding portion 311 does not overlap with the projection of the electrode extraction hole 231.

[0197] The projection 311 may be one or more. In some examples, the projection 311 is one and ring-shaped, and in other examples, the projection 311 is multiple, and the multiple projections 311 are spaced apart along the circumferential direction of the electrode extraction hole 231.

[0198] While the battery cell 7 is operating normally, the wall portion 23 can stop the protrusion 311, thereby reducing the risk of the electrode terminal 30 escaping from the electrode exit hole 231.

[0199] In some embodiments, the protrusion 311 is deformable when the internal pressure or temperature of the outer case 20 reaches a threshold.

[0200] The deformation of the protruding portion 311 includes, but is not limited to, fracture, bending, melting, etc.

[0201] When the internal pressure or temperature of the outer case 20 reaches a threshold, the protrusion 311 is deformable, thereby the wall 23 no longer stopping the protrusion 311, the electrode terminal 30 escapes through the electrode exit hole 231, the internal and external spaces of the outer case 20 communicate through the electrode exit hole 231, and the gas inside the outer case 20 is discharged through the electrode exit hole 231, reducing the risk of the battery cell 7 exploding.

[0202] For example, when the internal pressure or temperature of the outer case 20 reaches a threshold, the electrode terminal 30 moves outward from the electrode exit hole 231 due to the action of the internal pressure. In the process of the electrode terminal 30 moving, the protruding portion 311 is folded back and deformed under the action of the resistance of the wall portion 23, thereby allowing the protruding portion 311 to be pulled out from the electrode exit hole 231.

[0203] In some embodiments, L1 is the maximum dimension by which the protrusion 311 protrudes from the hole wall 231a of the electrode extraction hole 231, and L2 is the minimum distance between the periphery 23a of the wall portion 23 and the hole wall 231a of the electrode extraction hole 231. L1 and L2 satisfy 0.1 ≤ L1 / L2 ≤ 0.5.

[0204] For example, L1 may be the maximum dimension in the radial direction of the electrode extraction hole 231 to which the protrusion 311 protrudes from the hole wall 231a of the electrode extraction hole 231. For example, L2 may be the minimum distance between the periphery 23a of the wall portion 23 and the hole wall 231a of the electrode extraction hole 231 in the radial direction of the electrode extraction hole 231.

[0205] For example, if the wall portion 23 is an end cover 22, the periphery 23a of the wall portion 23 may be the outer peripheral edge of the end cover 22. If the wall portion 23 is an end wall 211, the periphery 23a of the wall portion 23 may be the connection point between the end wall 211 and the side wall 212.

[0206] There is a positive correlation between the value of L1 / L2 and the area of ​​the protrusion 311 that is blocked by the wall portion 23. The larger L1 / L2, the more difficult it is for the protrusion 311 to deform under the action of internal pressure, and the smaller L1 / L2, the less stable the electrode terminal 30 is at the wall portion 23.

[0207] The embodiment of the present invention improves the reliability of the battery cell 7 by limiting the L1 / L2 value to 0.5 or less, allowing the outer case 20 to deform immediately when the internal pressure or temperature reaches a threshold. The embodiment of the present invention improves the stability of the electrode terminals 30 in the wall portion 23 by limiting the L1 / L2 value to 0.1 or more, reducing the risk of the electrode terminals 30 falling off when the battery cell 7 is subjected to an external impact.

[0208] Selectively, the L1 / L2 value is 0.1, 0.2, 0.3, 0.4, or 0.5.

[0209] Selectively, the L1 / L2 value is between 0.2 and 0.3.

[0210] In some embodiments, L1 is the maximum dimension by which the protrusion 311 protrudes from the hole wall 231a of the electrode extraction hole 231, and T1 is the maximum thickness of the protrusion 311. L1 and T1 are 0.25 mm. 2 ≤L1×T1≤25mm 2 It satisfies the condition.

[0211] Both L1 and T1 affect the difficulty of deforming the protruding portion 311. The larger L1 is, the stronger the protruding portion 311 becomes, and the more difficult it is to deform the protruding portion 311. Similarly, the larger T1 is, the stronger the protruding portion 311 becomes, and the more difficult it is to deform the protruding portion 311.

[0212] In the embodiment of this application, the value of L1 × T1 is 25 mm 2 By limiting the following, the outer case 20 can deform immediately when the internal pressure or temperature reaches a threshold, thereby improving the reliability of the battery cell 7. In this embodiment, the value of L1 × T1 is 0.25 mm 2 By imposing these restrictions, the stability of the electrode terminals 30 in the wall portion 23 can be improved, reducing the risk of the electrode terminals 30 falling off when the battery cell 7 is subjected to external impact.

[0213] Selectively, the L1×T1 value is 0.25mm 2 , 0.5mm 2 , 1mm 2 , 5mm 2 , 8mm 2 , 10mm 2 , 15mm 2 , 20mm 2 or 25mm 2 That is the case.

[0214] Selectively, the value of L1×T1 is 1mm 2 ≤L1×T1≤5mm 2 That is the case.

[0215] In some embodiments, T1 is 0.5 mm to 5 mm. For example, T1 may be 0.5 mm, 0.8 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 4 mm, or 5 mm.

[0216] The embodiment of the present invention limits T1 to 0.5 mm to 5 mm, which allows the outer case 20 to deform immediately when the internal pressure or temperature reaches a threshold, and reduces the risk of the electrode terminals 30 falling off when the battery cell 7 is subjected to an external impact.

[0217] In some embodiments, L1 is 0.5 mm to 5 mm. For example, L1 may be 0.5 mm, 0.8 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 4 mm, or 5 mm.

[0218] In some embodiments, the thickness of at least a portion of the projection 311 gradually decreases in the direction from the central axis X of the electrode extraction hole 231 toward the outer peripheral edge 311a of the projection 311.

[0219] The protrusion 311 includes a thickness-changing region in which the thickness gradually decreases. The thickness is greatest at one end of the thickness-changing region that is close to the central axis X of the electrode extraction hole 231, and the thickness is greatest at the other end that is close to the outer peripheral edge 311a of the protrusion 311 in the thickness-changing region.

[0220] In this invention, by providing a thickness-changing region in the protrusion 311 in which the thickness gradually decreases, the protrusion 311 becomes more easily deformed by the action of internal pressure, thereby immediately reducing the pressure and improving the reliability of the battery cell 7.

[0221] In some embodiments, the projection 311 has a first surface 311b facing the wall 23, the wall 23 has a second surface 232 facing the projection 311, the second surface 232 is perpendicular to the thickness direction Z of the wall 23, and the first surface 311b is inclined with respect to the second surface 232 in a direction toward approaching the electrode assembly 10.

[0222] For example, in the thickness direction Z of the wall portion 23, the distance between one end of the first surface 311b away from the electrode extraction hole 231 and the second surface 232 is greater than the distance between the one end of the first surface 311b close to the electrode extraction hole 231 and the second surface 232.

[0223] When the internal pressure or temperature of the outer case 20 reaches a threshold, the inclined first surface 311b can induce deformation of the protrusion 311, thereby facilitating the protrusion 311 to be pulled out from the electrode extraction hole 231, and the pressure is immediately reduced, improving the reliability of the battery cell 7.

[0224] In some embodiments, the projection 311 has a third surface 311c opposite to the wall 23, and the third surface 311c is parallel to the second surface 232. The thickness of the projection 311 gradually decreases in the direction from the central axis X of the electrode extraction hole 231 toward the outer peripheral edge 311a of the projection 311.

[0225] In some embodiments, the electrode terminals 30 include a terminal body 32 and a first stopper portion 31 that are connected to each other, with at least a portion of the terminal body 32 housed in an electrode lead-out hole 231, and the first stopper portion 31 located on the side of the wall portion 23 facing the electrode assembly 10 and protruding from the outer peripheral surface 321 of the terminal body 32. The first stopper portion 31 includes a protruding portion 311.

[0226] The first stopper portion 31 may include only the protruding portion 311, or it may include other parts besides the protruding portion 311.

[0227] The first stopper portion 31 may be one or multiple. Selectively, the first stopper portion 31 may be one and have a ring structure.

[0228] By positioning the terminal body 32 so that it fits into the electrode lead-out hole 231, it becomes easier to connect the electrode terminal 30 to other external components of the battery cell 7. The wall portion 23 forms a barrier against the protruding portion 311, thereby limiting the electrode terminal 30 from detaching from the inside of the outer case 20.

[0229] In some embodiments, the electrode terminal 30 further includes a second stopper portion 33, which protrudes from the outer peripheral surface 321 of the terminal body 32 and is located outside the wall portion 23. In the thickness direction Z of the wall portion 23, at least a portion of the wall portion 23 is located between the protruding portion 311 and the second stopper portion 33.

[0230] The wall portion 23 is positioned between the first stopper portion 31 and the second stopper portion 33, thereby limiting the relative movement between the electrode terminal 30 and the wall portion 23.

[0231] In some embodiments, in the radial direction of the electrode lead-out hole 231, the end of the second stopper portion 33 away from the terminal body 32 extends beyond the end of the first stopper portion 31 away from the terminal body 32.

[0232] In the radial direction of the electrode lead-out hole 231, the second stopper portion 33 has a larger dimension than the first stopper portion 31, thereby increasing the exposed area of ​​the electrode terminal 30, facilitating connection between the electrode terminal 30 and the external bus member, increasing the connection area between the electrode terminal 30 and the bus member, and improving the current flow capability. In the radial direction of the electrode lead-out hole 231, the first stopper portion 31 has a larger dimension than the second stopper portion 33, thereby making the outer case 20 more prone to deformation when the internal pressure or temperature reaches a threshold, allowing for immediate pressure reduction and improving the reliability of the battery cell 7.

[0233] In some embodiments, the first stopper portion 31, the second stopper portion 33, and the terminal body 32 are integrally molded. The embodiments of the present invention can improve the overall structural strength of the electrode terminal 30, reduce the internal resistance of the electrode terminal 30, and improve the current passage capability.

[0234] In some embodiments, the battery cell 7 further includes a sealing member 50, at least a portion of which is provided between the first stopper portion 31 and the wall portion 23.

[0235] For example, both the electrode terminals 30 and the sealing member 50 separate the internal and external spaces of the outer case 20, improving the sealing performance of the battery cell 7.

[0236] The sealing member 50 can be filled into the gap between the first stopper portion 31 and the wall portion 23, thereby sealing the electrode extraction hole 231.

[0237] In some embodiments, the sealing member 50 is compressed and sandwiched between a portion of the first stopper portion 31 and the wall portion 23 to seal the electrode extraction hole 231.

[0238] In some embodiments, a portion of the sealing member 50 is provided between the second stopper portion 33 and the wall portion 23.

[0239] In some embodiments, a portion of the sealing member 50 is provided in the electrode exit hole 231, and the hole wall 231a of the electrode exit hole 231 is isolated from the terminal body 32.

[0240] In some embodiments, the sealing member 50 is made of an insulating material. The sealing member 50 can insulate and separate the wall portion 23 from the electrode terminal 30.

[0241] In some embodiments, the battery cell 7 further includes an insulating member 60, which is provided on the surface of the wall portion 23 facing the electrode assembly 10. The insulating member 60 is used to insulate and separate at least a portion of the electrode assembly 10 from the wall portion 23.

[0242] In some embodiments, the projection of the wall portion 23 along its own thickness direction Z is annular. Selectively, the battery cell 7 is a cylindrical battery cell.

[0243] Figure 9 is a schematic local cross-sectional view of a battery cell according to some embodiments of the present application, and Figure 10 is a schematic view of the electrode terminals shown in Figure 9.

[0244] As shown in Figures 9 and 10, in some embodiments, the first stopper portion 31 is provided with a thinned portion 313, and the first stopper portion 31 is capable of bending or breaking along the thinned portion 313 when the internal pressure or temperature of the outer case 20 reaches a threshold.

[0245] The weak portion 313 is a part of the first stopper portion 31 where the strength is relatively low, and where the first stopper portion 31 is easily ruptured or bent. For example, the strength of the weak portion 313 is lower than the strength of the part of the first stopper portion 31 adjacent to the weak portion 313.

[0246] In some examples, the present invention can provide grooves, shallow grooves, through holes, or other structures in a predetermined area of ​​the first stopper portion 31, thereby reducing the local strength of the first stopper portion 31 and forming a weak portion 313 in the first stopper portion 31. For example, a process to reduce the thickness is performed on a predetermined area of ​​the first stopper portion 31, thereby forming a weak portion 313 in the portion of the first stopper portion 31 that has undergone the thickness-reducing process. In another example, a material treatment may be performed on a predetermined area of ​​the first stopper portion 31 so that the strength of that area is less than the strength of the other areas, i.e., that area is a weak portion 313.

[0247] For example, the thin portion 313 may be entirely provided on the protruding portion 311, or only a portion of it may be provided on the protruding portion 311. Alternatively, the entire thin portion 313 may be provided on a part of the first stopper portion 31 other than the protruding portion 311.

[0248] By installing the thinned portion 313 on the first stopper portion 31, when the internal pressure or temperature of the outer case 20 reaches a threshold, the difficulty of deformation of the first stopper portion 31 is reduced, allowing the first stopper portion 31 to bend or break at a predetermined position. This allows the internal and external spaces of the outer case 20 to communicate through the electrode extraction hole 231, thereby reducing the risk of the battery cell 7 exploding.

[0249] In some embodiments, at least a portion of the projection of the thin portion 313 in the thickness direction Z of the wall portion 23 lies within the electrode extraction hole 231.

[0250] The projection of the thin portion 313 in the thickness direction Z overlaps, at least partially, with the projection of the electrode extraction hole 231 in the thickness direction Z.

[0251] In the embodiment of the present invention, when the internal pressure or temperature of the outer case 20 reaches a threshold, the curved portion of the first stopper portion 31 is brought closer to the electrode extraction hole 231, thereby making it easier to pull out the first stopper portion 31 from the electrode extraction hole 231.

[0252] In some embodiments, the first stopper portion 31 includes a protruding portion 311 and a connecting portion 312, the connecting portion 312 being used to connect the protruding portion 311 and the terminal body 32, and the projection of the connecting portion 312 in the thickness direction Z of the wall portion 23 is located between the outer peripheral surface 321 of the terminal body 32 and the hole wall 231a of the electrode extraction hole 231. The thin portion 313 is provided on the connecting portion 312.

[0253] In some examples, a portion of the connecting portion 312 is a thin portion 313, while in an alternative embodiment, the entire connecting portion 312 is a thin portion 313.

[0254] The projection of the thin portion 313 in the thickness direction Z of the wall portion 23 is entirely located within the electrode extraction hole 231.

[0255] For example, if the internal pressure or temperature of the outer case 20 reaches a threshold, the protrusion 311 can be reversed along with the curvature of the weakened portion 313, thereby clearing the wall portion 23 and being pulled out from the electrode extraction hole 231. The embodiment of the present application, by providing the weakened portion 313 at the connecting portion 312, relaxes the limitations on the strength of the protrusion 311 and allows for greater flexibility in the shape design of the protrusion 311.

[0256] For example, if the internal pressure or temperature of the outer case 20 reaches a threshold, the first stopper portion 31 will rupture along the weak portion 313, thereby freeing the wall portion 23 from being constrained to the terminal body 32 via the protrusion 311, and allowing the terminal body 32 to be pulled out from the electrode extraction hole 231.

[0257] In some embodiments, a shallow groove 314 is provided in the electrode terminal 30, and the thin portion 313 is formed at the bottom of the shallow groove 314. By forming the thin portion 313 in a manner that creates the shallow groove 314, the molding efficiency of the electrode terminal 30 can be improved.

[0258] In some embodiments, the shallow groove 314 is provided on the surface of the first stopper portion 31 opposite to the wall portion 23.

[0259] When the internal pressure or temperature of the outer case 20 reaches a threshold, the shallow groove 314 provides space for the material to flow and helps to curve the first stopper portion 31.

[0260] Figure 11 is a schematic cross-sectional view of the electrode terminals of a battery cell according to another embodiment of the present application.

[0261] As shown in Figure 11, in some embodiments, the shallow groove 314 is provided on the surface facing the wall portion 23 of the first stopper portion 31.

[0262] In some embodiments, the current collector 40 is in contact with the surface of the first stopper portion 31 opposite to the wall portion 23. A shallow groove 314 is provided on the surface of the first stopper portion 31 facing the wall portion 23, which reduces the influence of the contact area of ​​the shallow groove 314 on the first stopper portion 31 and the current collector 40, thereby improving the current passage capability.

[0263] In some embodiments, a portion of the sealing member 50 is filled into the shallow groove 314.

[0264] In some embodiments, a shallow groove 314 is provided on the surface of the first stopper portion 31 facing the wall portion 23, and another shallow groove 314 is provided on the surface of the first stopper portion 31 opposite to the wall portion 23, and a thin portion 313 is formed between the two shallow grooves 314.

[0265] Figure 12 is a schematic cross-sectional view of a battery cell according to some embodiments of the present application, and Figure 13 is a schematic cross-sectional view of the electrode terminals shown in Figure 12.

[0266] As shown in FIGS. 12 and 13, in some embodiments, the electrode terminal 30 is provided with a recess 34. Along the thickness direction Z of the wall portion 23, the recess 34 is recessed from the inside of the outer case 20 toward the outside of the outer case 20. At least a part of the recess 34 is provided on the side facing the tab 11 of the terminal body 32.

[0267] When the internal pressure or temperature of the outer case 20 reaches a threshold value, the first stopper portion 31 is bent, and the recess 34 can provide a space for the material to flow during the process of bending the first stopper portion 31, thereby reducing the resistance to the bending of the first stopper portion 31 and enabling the first stopper portion 31 to be immediately pulled out from the electrode lead-out hole 231.

[0268] In some embodiments, the recess 34 includes a first side surface 341 and a second side surface 342. The first side surface 341 is provided along the radially outer side of the electrode lead-out hole 231 of the second side surface 342. The first side surface 341 is connected to the bottom surface 343 of the recess 34 and is installed inclined toward the side away from the central axis Y of the electrode terminal 30.

[0269] Exemplarily, that the first side surface 341 is provided outside the second side surface 342 may mean that the first side surface 341 is located on the side away from the central axis Y of the electrode terminal 30 of the second side surface 342 along the radial direction of the electrode lead-out hole 231.

[0270] The bottom surface 343 of the recess 34 may be a flat surface or a curved surface. Exemplarily, the first side surface 341 and the second side surface 342 are respectively connected to both ends of the bottom surface 343.

[0271] Exemplarily, the central axis Y of the electrode terminal 30 may be parallel to the central axis X of the electrode lead-out hole 231.

[0272] Optionally, the central axis Y of the electrode terminal 30 may overlap with the central axis X of the electrode lead-out hole 231. Of course, due to process errors, the central axis Y of the electrode terminal 30 may be offset by a certain distance from the central axis X of the electrode lead-out hole 2X.

[0273] By installing the first side surface 341 obliquely, when the first stopper portion 31 is bent, more space for the material to flow can be provided, reducing the resistance to the bending of the first stopper portion 31.

[0274] In some embodiments, the recess 34 includes a first side surface 341 and a second side surface 342. The first side surface 341 is provided along the radially outer side of the electrode lead-out hole 231 of the second side surface 342. The second side surface 342 is connected to the bottom surface 343 of the recess 34 and is installed obliquely toward the side close to the central axis Y of the electrode terminal 30.

[0275] By installing the second side surface 342 obliquely, when the first side surface 341 is deformed by the flow of the material, the risk of interference between the second side surface 342 and the first side surface 341 is reduced, and the resistance to the bending of the first stopper portion 31 is reduced.

[0276] In some embodiments, the first side surface 341 is connected to the bottom surface 343 of the recess 34 and is installed obliquely toward the side away from the central axis Y of the electrode terminal �0. The second side surface 342 is connected to the bottom surface 343 of the recess 34 and is installed obliquely toward the side close to the central axis Y of the electrode terminal 30.

[0277] In some embodiments, the first stopper portion 31 can be curved in the direction approaching the recess 34 when the internal pressure or temperature of the outer case 20 reaches the threshold value.

[0278] When the internal pressure or temperature of the outer case 20 reaches the threshold value, the first stopper portion 31 curves in the direction approaching the recess 34, whereby the material flows toward the recess 34, the resistance to the bending of the first stopper portion 31 is reduced, and the first stopper portion 31 can be immediately pulled out from the electrode lead-out hole 231.

[0279] In some embodiments, the first stopper portion 31 is formed by folding back a part of the electrode terminal 30.

[0280] During assembly, the electrode terminal 30 can be inserted into the outer case 20 through the electrode exit hole 231, and then a part of the electrode terminal 30 is folded back to form the first stopper portion 31, thereby fixing the electrode terminal 30 to the wall portion 23.

[0281] In some embodiments, when inserting the electrode terminal 30 into the outer case 20 from the outside through the electrode exit hole 231, the electrode terminal 30 may be pressed from the inside, thereby bending a part of the electrode terminal 30 and forming a flange-shaped first stopper portion 31.

[0282] A recess 34 may be formed in the portion of the electrode terminal 30 that is pressed by an external workpiece.

[0283] In some embodiments, the terminal body 32 includes a terminal projection 322, and the recess 34 is positioned around the terminal projection 322. In the thickness direction Z of the wall portion 23, the end face 322a of the terminal projection 322 facing the tab 11 is closer to the tab 11 than the first stopper portion 31.

[0284] In the embodiment of the present invention, the first stopper portion 31 is less likely to interfere with the contact between the terminal protrusion 322 and other members (for example, the tab 11 or the current collector member 40), thereby reducing excessive positioning and reducing the risk of poor contact between the terminal protrusion 322 and other members due to the irregularities of the first stopper portion 31, thereby improving the current passage capability and reliability of the battery cell 7.

[0285] Figure 14 is a schematic cross-sectional view of the electrode terminals of a battery cell according to another embodiment of the present application.

[0286] As shown in Figure 14, in some embodiments, a recess 34 is provided on the side of the terminal body 32 facing the tab 11, and a thinned portion 313 is provided on the first stopper portion 31.

[0287] By simultaneously installing the thin portion 313 and the recess 34, when the internal pressure or temperature of the outer case 20 reaches a threshold, the resistance of the first stopper portion 31 to bending can be further reduced, and the first stopper portion 31 can be immediately pulled out from the electrode extraction hole 231.

[0288] Figure 15 is a schematic cross-sectional view of a battery cell according to another embodiment of the present invention, and Figure 16 is a schematic cross-sectional view of the electrode terminals shown in Figure 15.

[0289] As shown in Figures 15 and 16, in some embodiments, the electrode terminal 30 includes a terminal body 32, a first stopper portion 31 and a second stopper portion 33, where at least a portion of the terminal body 32 is housed in an electrode exit hole 231, the first stopper portion 31 is located on the side of the wall portion 23 facing the electrode assembly 10 and protrudes from the outer peripheral surface 321 of the terminal body 32, the second stopper portion 33 is located on the side of the wall portion 23 opposite to the electrode assembly 10 and protrudes from the outer peripheral surface 321 of the terminal body 32, and in the thickness direction Z, at least a portion of the wall portion 23 is sandwiched between the first stopper portion 31 and the second stopper portion 33.

[0290] In some embodiments, a shallow groove 314 is provided in the first stopper portion 31 to form a thin portion 313.

[0291] In some embodiments, the terminal body 32 is provided with a through hole 323, which is used for injecting an electrolyte. In some embodiments, the electrode terminal 30 further includes a sealing plate 35, which is connected to the terminal body 32 and seals the through hole 323.

[0292] In some embodiments, the terminal body 32, the first stopper portion 31, and the second stopper portion 33 are integrally structured, and the sealing plate 35 is welded to the terminal body 32.

[0293] In some embodiments, the through-hole 323 is a stepped hole. At least a portion of the sealing plate 35 is housed within the through-hole 323 and in contact with the stepped surface.

[0294] FIG. 17 is a schematic perspective view of a battery cell according to another embodiment of the present application.

[0295] As shown in FIG. 17, in some embodiments, the projection of the wall portion 23 along its own thickness direction Z is rectangular.

[0296] In some embodiments, the battery cell 7 is a rectangular battery cell.

[0297] In some embodiments, the wall portion 23 is the end cover 22.

[0298] According to some embodiments of the present application, the present application further provides a battery including a plurality of battery cells 7 of any of the above embodiments.

[0299] According to some embodiments of the present application, the present application further provides a power consumption device including the battery cell 7 of any of the above embodiments used to supply electrical energy. The power consumption device may be a device or system that uses any of the above battery cells 7.

[0300] Referring to FIGS. 5 to 8, an embodiment of the present application provides a cylindrical battery cell 7 including an outer case 20, an electrode assembly 10, an electrode terminal 30, a current collector member 40, and a seal member 50.

[0301] The outer case 20 includes a housing 21 and an end cover 22. One end of the housing 21 has an opening, and the end cover 22 covers the opening. The housing 21 includes a side wall 212 and an end wall 211. The side wall 212 surrounds the outside of the electrode assembly 10, and the end wall 211 is installed opposite to the opening. An electrode lead-out hole 231 is provided in the end wall 211.

[0302] The electrode assembly 10 is housed in the outer case 20 and includes tabs 11. The electrode terminal 3 is installed on the end wall and is electrically connected to the tabs through the current collector member 40.

[0303] The electrode terminal 30 includes a terminal body 32, a first stopper portion 31, and a second stopper portion 33. At least a portion of the terminal body 32 is housed in the electrode exit hole 231. The first stopper portion 31 is located on the side of the end wall 211 facing the electrode assembly 10 and protrudes from the outer circumferential surface 321 of the terminal body 32. The second stopper portion 33 is located on the side of the end wall 211 opposite to the electrode assembly 10 and protrudes from the outer circumferential surface 321 of the terminal body 32. In the thickness direction Z, at least a portion of the end wall 211 is located between the first stopper portion 31 and the second stopper portion 33.

[0304] The sealing member 50 isolates the electrode terminal 30 from the end wall 211, and both the electrode terminal 30 and the sealing member 50 cover the electrode exit hole 231, thereby sealing the electrode exit hole 231.

[0305] When the internal pressure or temperature of the outer case 20 reaches a threshold, the first stopper portion 31 is bendable and deformable, and the entire electrode terminal 30 is detached from the end wall 211, thereby connecting the internal and external spaces of the outer case 20 through the electrode extraction hole 231 and discharging the gas inside the outer case 20.

[0306] While the present application has been described with reference to preferred embodiments, various improvements can be made and components can be replaced with equivalents without departing from the scope of the application, and in particular, each technical feature mentioned in each embodiment can be combined in any way, provided that there is no structural inconsistency. The present application is not limited to the specific embodiments disclosed herein and includes all technical solutions included in the claims.

Claims

1. An outer case including a wall portion provided with electrode extraction holes, At least a portion of the electrode assembly, including tabs, is housed within the outer case. A battery cell comprising an electrode terminal installed on the wall portion and covering at least a portion of the electrode extraction hole, and electrically connected to the tab, At least a portion of the electrode terminals is deformable when the internal pressure or temperature of the outer case reaches a threshold, so that the internal and external spaces of the outer case communicate through the electrode extraction holes and gas is discharged from inside the outer case. The electrode terminal includes a projection that protrudes from the wall of the electrode extraction hole along the radial direction of the electrode extraction hole, the projection is located on the side of the wall facing the electrode assembly, and the projection is deformable when the internal pressure or temperature of the outer case reaches the threshold. The electrode terminals include a terminal body and a first stopper portion that are connected to each other, at least a portion of the terminal body is housed in the electrode exit hole, and the first stopper portion is located on the side of the wall facing the electrode assembly and protrudes from the outer circumferential surface of the terminal body. The first stopper portion includes the protruding portion, A thin portion is provided in the first stopper portion, and the first stopper portion is capable of bending or breaking along the thin portion when the internal pressure or temperature of the outer case reaches the threshold. A battery cell in which shallow grooves are provided on the electrode terminals, and the thin portion is formed at the bottom of the shallow grooves.

2. The battery cell according to claim 1, wherein at least a portion of the electrode terminals can detach from the wall portion when the internal pressure or temperature of the outer case reaches the threshold.

3. If L1 is the maximum dimension by which the protruding portion extends beyond the hole wall of the electrode extraction hole, and L2 is the minimum distance between the periphery of the wall portion and the hole wall of the electrode extraction hole, The battery cell according to claim 1, wherein L1 and L2 satisfy 0.1 ≤ L1 / L2 ≤ 0.

5.

4. If L1 is the maximum dimension of the protrusion that extends from the hole wall of the electrode extraction hole, and T1 is the maximum thickness of the protrusion, L1 and T1 are 0.25 mm 2 ≤L1 × T1 ≤ 25 mm 2 A battery cell according to claim 1, satisfying the requirements.

5. The battery cell according to claim 4, wherein T1 is 0.5 mm to 5 mm.

6. The battery cell according to claim 1, wherein the thickness of at least a portion of the protrusion gradually decreases in the direction from the central axis of the electrode extraction hole toward the outer edge of the protrusion.

7. The battery cell according to claim 1, wherein the protrusion has a first surface facing the wall, the wall has a second surface facing the protrusion, the second surface is perpendicular to the thickness direction of the wall, the first surface is inclined with respect to the second surface in a direction approaching the electrode assembly, and in the thickness direction of the wall, the distance between one end of the first surface away from the electrode extraction hole and the second surface is greater than the distance between one end of the first surface close to the electrode extraction hole and the second surface.

8. The battery cell according to claim 1, wherein at least a portion of the projection of the thin portion in the thickness direction of the wall portion is located within the electrode extraction hole.

9. The first stopper portion includes a protruding portion and a connecting portion, the connecting portion is used to connect the protruding portion and the terminal body, and the projection of the connecting portion in the thickness direction of the wall portion is located between the outer circumferential surface of the terminal body and the hole wall of the electrode extraction hole. The battery cell according to claim 8, wherein the thin portion is provided at the connection portion.

10. The shallow groove is provided on the surface of the first stopper portion facing the wall portion, and / or The battery cell according to claim 1, wherein the shallow groove is provided on the surface of the first stopper portion opposite to the wall portion.

11. The battery cell according to claim 1, wherein the electrode terminal is provided with a recess, and along the thickness direction of the wall portion, the recess is recessed from the inside of the outer case toward the outside of the outer case, and at least a portion of the recess is provided on the side of the terminal body facing the tab.

12. The battery cell according to claim 11, wherein the recess includes a first side surface and a second side surface, the first side surface is provided along the radially outer side of the electrode extraction hole of the second side surface, the first side surface is connected to the bottom surface of the recess and is installed at an angle toward the side away from the central axis of the electrode terminal.

13. The battery cell according to claim 11, wherein the recess includes a first side surface and a second side surface, the first side surface is provided along the radially outer side of the electrode extraction hole of the second side surface, and the second side surface is connected to the bottom surface of the recess and is installed at an angle toward the side closer to the central axis of the electrode terminal.

14. The battery cell according to claim 11, wherein the first stopper portion is bendable toward the recess when the internal pressure or temperature of the outer case reaches the threshold.

15. The battery cell according to claim 11, wherein the first stopper portion is formed by folding back a part of the electrode terminal.

16. The terminal body includes a terminal projection, and the recess is provided around the terminal projection. The battery cell according to claim 11, wherein, in the thickness direction of the wall portion, the end face of the terminal protrusion facing the tab is closer to the tab than the first stopper portion.

17. The electrode terminal further includes a second stopper portion, the second stopper portion protruding from the outer circumferential surface of the terminal body and installed outside the wall portion. The battery cell according to claim 1, wherein in the thickness direction of the wall portion, at least a portion of the wall portion is located between the protruding portion and the second stopper portion.

18. The battery cell according to claim 17, wherein, in the radial direction of the electrode lead-out hole, the end of the second stopper portion away from the terminal body extends beyond the end of the first stopper portion away from the terminal body.

19. The battery cell according to claim 17, wherein the first stopper portion, the second stopper portion, and the terminal body are integrally molded.

20. The battery cell according to claim 1, further comprising a sealing member, wherein at least a portion of the sealing member is provided between the first stopper portion and the wall portion.

21. The battery cell according to claim 1, wherein the melting point of the electrode terminal is lower than the melting point of the wall portion.

22. The battery cell according to claim 21, wherein the melting point of the electrode terminal is H1 and the melting point of the wall portion is H2, and H2 - H1 ≥ 300°C.

23. The battery cell according to claim 1, wherein the material of the electrode terminals includes aluminum or copper, and the material of the wall portion includes steel.

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

25. The battery cell according to claim 1, wherein the projection of the wall portion along its own thickness direction is rectangular or annular.

26. A battery comprising a battery cell according to any one of claims 1 to 25.

27. A power consumption device including a battery according to claim 26 for supplying electrical energy.

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