Battery cell, battery, and electric device

Abstract

Provided are a battery cell, a battery, and an electric device. The battery cell comprises a casing, an electrode assembly, an electrode terminal, and a pressure relief mechanism; the casing has a wall portion; the electrode assembly is accommodated in the casing; the electrode assembly comprises a first electrode lead-out portion and a second electrode lead-out portion; the polarity of the first electrode lead-out portion is opposite to the polarity of the second electrode lead-out portion; the first electrode lead-out portion is welded to the wall portion to form a weld mark portion; the electrode terminal is mounted on the wall portion in an insulated manner, and the electrode terminal is electrically connected to the second electrode lead-out portion; the pressure relief mechanism is arranged on the wall portion and comprises a weak portion, and the weak portion is configured to at least partially crack when the battery cell releases pressure; in the direction perpendicular to the thickness direction of the wall portion, the weak portion is located between the weld mark portion and the electrode terminal. The first electrode lead-out portion is electrically connected to the wall portion, and the second electrode lead-out portion is electrically connected to the electrode terminal, so that the electrical energy of the electrode assembly can be outputted by means of the wall portion and the electrode terminal, thereby reducing the number of electrode terminals, reducing the occupation of the internal space of a battery, and improving the energy density.

Description

Battery cells, batteries and electrical equipment Cross-reference to related applications

[0001] This application claims priority to Chinese patent application filed on July 11, 2024, entitled “Battery Cell, Battery and Electrical Device” (application number: 2024109311480), the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of batteries, and more specifically, to a battery cell, a battery, and an electrical device. Background Technology

[0003] Batteries are widely used in the new energy field, such as in electric vehicles and new energy vehicles, which have become a new trend in the automotive industry. The development of battery technology must consider multiple design factors simultaneously, such as battery life, discharge capacity, and charge / discharge rate. Additionally, battery energy density also needs to be considered. However, the energy density of current batteries is relatively low. Summary of the Invention

[0004] The purpose of this application is to provide a battery cell, a battery, and an electrical device, which aims to improve the problem of low energy density in batteries in related technologies.

[0005] In a first aspect, embodiments of this application provide a battery cell, the battery cell including a housing, an electrode assembly, and electrode terminals, the housing having a wall portion; the electrode assembly being housed within the housing, the electrode assembly including a first electrode lead and a second electrode lead, the first electrode lead and the second electrode lead having opposite polarities, the first electrode lead being electrically connected to the wall portion; the electrode terminals being insulatedly mounted on the wall portion, the electrode terminals being electrically connected to the second electrode lead.

[0006] In the above technical solution, the first electrode lead is electrically connected to the wall, and the second electrode lead is electrically connected to the electrode terminal. This allows for the output or input of electrical energy to the electrode assembly through the wall and electrode terminals. On one hand, this reduces the number of electrode terminals required, lowering costs, reducing the space occupied inside the battery, and increasing energy density. On the other hand, once the information acquisition device is electrically connected to the wall, it can collect usage information from individual battery cells. This facilitates the connection of the information acquisition device to individual battery cells and data collection, reducing the difficulty of data collection from individual battery cells and further lowering manufacturing costs.

[0007] As an optional technical solution in this application embodiment, the first electrode lead-out portion is welded to the wall portion to form a solder mark portion; the battery cell includes a pressure relief mechanism, the pressure relief mechanism is disposed on the wall portion, the pressure relief mechanism includes a weak portion, and the pressure relief mechanism is configured to be able to crack along at least a portion of the weak portion when the battery cell is depressurized; wherein, along a direction perpendicular to the thickness direction of the wall portion, the weak portion is disposed between the solder mark portion and the electrode terminal.

[0008] In the above technical solution, by setting a pressure relief mechanism, the pressure relief mechanism can crack along at least a portion of the weak part when the battery cell is depressurized, so as to release the internal pressure of the battery cell. The weak part is set between the solder part and the electrode terminal in a direction perpendicular to the thickness direction of the wall, so that when the weak part cracks, it can open a larger opening, which is conducive to the rapid depressurization of the battery cell.

[0009] As an optional technical solution in this application embodiment, the weak part is an annular structure surrounding the electrode terminal, and the minimum distance between the weak part and the solder mark is less than the minimum distance between the weak part and the electrode terminal along the direction perpendicular to the thickness of the wall.

[0010] In the above technical solution, the weak part is a ring structure surrounding the electrode terminal. The weak part divides the pressure relief mechanism into two parts, one part located on the outside of the weak part and the other part located on the inside of the weak part. Along the direction perpendicular to the thickness of the wall, by making the minimum distance between the weak part and the solder joint less than the minimum distance between the weak part and the electrode terminal (i.e., the weak part is located close to the solder joint), when the battery cell is depressurized, the part of the pressure relief mechanism located on the inside of the weak part experiences a greater force from the gas. This allows the part of the pressure relief mechanism located on the inside of the weak part to open for pressure relief, forming a larger opening for gas to escape. The larger pressure relief area during battery cell depressurization facilitates rapid pressure relief for the battery cell.

[0011] As an optional technical solution in this application embodiment, the weak part is an annular structure surrounding the electrode terminal, and the minimum distance between the weak part and the solder mark is greater than the minimum distance between the weak part and the electrode terminal along the direction perpendicular to the thickness of the wall.

[0012] In the above technical solution, the weak part is a ring structure surrounding the electrode terminal. The weak part divides the pressure relief mechanism into two parts, one part located on the outside of the weak part and the other part located on the inside of the weak part. Along the direction perpendicular to the thickness of the wall, by making the minimum distance between the weak part and the solder joint greater than the minimum distance between the weak part and the electrode terminal, that is, by setting the weak part close to the electrode terminal, when the battery cell is depressurized, the part of the pressure relief mechanism located on the outside of the weak part is subjected to a greater force from the gas. The part of the pressure relief mechanism located on the outside of the weak part can open to release pressure, making it less likely for the electrode terminal to detach from the wall and less likely to come into contact with other electrical connection components and cause a short circuit.

[0013] As an optional technical solution in this application embodiment, the minimum distance between the weak part and the solder mark part along the direction perpendicular to the thickness direction of the wall is A, which satisfies: A≥3mm.

[0014] In the above technical solution, by making the minimum distance between the weak part and the soldering part in the direction perpendicular to the thickness of the wall part greater than or equal to 3mm, it is beneficial to reduce the impact of high heat on the weak part when welding the first electrode lead-out part and the wall part, reduce the risk of the weak part cracking prematurely, and improve the life of the battery cell.

[0015] As an optional technical solution in this application embodiment, the minimum distance between the weak part and the electrode terminal along the direction perpendicular to the thickness direction of the wall is B, which satisfies: B≥4mm.

[0016] In the above technical solution, by making the minimum distance between the weak part and the electrode terminal in the direction perpendicular to the thickness of the wall greater than or equal to 4mm, the distance between the weak part and the electrode unit is larger, which can reduce the inhibitory effect of the electrode terminal on the deformation of the weak part, thereby facilitating the timely cracking of the weak part when the battery cell is depressurized, and improving the timeliness of the battery cell depressurization.

[0017] As an optional technical solution in this application embodiment, both the solder mark portion and the weak portion are annular structures arranged around the electrode terminal.

[0018] In the above technical solution, the soldering part is a ring structure, which is arranged around the outside of the electrode terminal. In this way, the first electrode lead-out part can be stably connected to the wall and has a large current-passing area. By setting the weak part as a ring structure, when the battery cell is depressurized, the depressurization mechanism can split along the weak part, thereby opening a larger opening to facilitate rapid depressurization of the battery cell.

[0019] As an optional technical solution in this application embodiment, the pressure relief mechanism is provided with a pressure relief groove, and the pressure relief mechanism forms the weak part in the area where the pressure relief groove is provided.

[0020] In the above technical solution, the weak part is formed by opening a pressure relief groove on the pressure relief mechanism, which is simple, convenient and low in cost.

[0021] As an optional technical solution in this application embodiment, the pressure relief groove is disposed on the surface of the pressure relief mechanism away from the interior of the outer shell.

[0022] In the above technical solution, by setting the pressure relief groove on the surface of the pressure relief mechanism away from the inside of the housing, the tension that the weak part needs to overcome when it cracks is smaller, making it easier to crack.

[0023] As an optional technical solution in this application embodiment, the first electrode lead-out portion includes a first electrode tab and a first current collector, the first current collector being electrically connected to the first electrode tab and the wall portion, and the first current collector being welded to the wall portion to form the solder mark portion.

[0024] In the above technical solution, by setting the first current collector, it is easy to realize the electrical connection between the first electrode tab and the wall, and reduce the difficulty of connecting the electrode assembly and the wall.

[0025] As an optional technical solution in this application embodiment, the first current collecting member and the wall portion are arranged along the thickness direction of the wall portion, the wall portion and the first current collecting member are penetrated and welded, and a portion of the weld mark protrudes from the surface of the wall portion away from the inside of the outer shell.

[0026] In the above technical solution, through-welding is used to connect the first current collector to the wall, which is simple, convenient, and produces high-quality welds. Furthermore, during through-welding, the welding direction is approximately perpendicular to the thickness direction of the wall, which reduces the impact on weak points, lowers the risk of premature cracking in these areas, and helps improve the lifespan of the battery cells.

[0027] As an optional technical solution in this application embodiment, the pressure relief mechanism is integrally formed with the wall portion.

[0028] In the above technical solution, the pressure relief mechanism is integrally formed with the wall, eliminating the need for additional welding or bonding processes, which helps reduce the risk of leakage from the pressure relief mechanism. Furthermore, during production, it is easier to ensure that the detonation pressure of multiple battery cells produced is relatively consistent.

[0029] As an optional technical solution in this application embodiment, the pressure relief mechanism is separately disposed from the wall portion, the wall portion is provided with a pressure relief hole, and the pressure relief mechanism is installed on the wall portion and covers the pressure relief hole.

[0030] In the above technical solution, the pressure relief mechanism and the wall part are separately set and installed on the wall part to facilitate processing and manufacturing.

[0031] As an optional technical solution in this application embodiment, the first electrode lead-out portion includes a first electrode tab, and the second electrode lead-out portion includes a second electrode tab. Along the thickness direction of the wall portion, the first electrode tab and the second electrode tab are formed at the same end of the electrode assembly.

[0032] In the above technical solution, by forming the first electrode and the second electrode on the same end of the electrode assembly, it is simpler and more convenient to electrically connect the first electrode to the wall and the second electrode to the electrode terminal, which helps to reduce manufacturing costs.

[0033] As an optional technical solution in this application embodiment, the housing includes a shell and an end cap. The shell has a receiving space with an opening at one end, and the receiving space is used to receive the electrode assembly. The end cap is connected to the shell and closes the opening. The end cap is the wall portion.

[0034] In the above technical solution, when the end cover is a wall portion, the first electrode lead-out portion is connected to the end cover, and the electrode terminal is set on the end cover, which is simple and convenient to manufacture.

[0035] As an optional technical solution in this application embodiment, the battery cell is a cylindrical battery cell.

[0036] Secondly, embodiments of this application also provide a battery, the battery comprising the aforementioned battery cell.

[0037] Thirdly, embodiments of this application also provide an electrical device, the electrical device including the aforementioned battery cell, the battery cell being used to provide electrical energy to the electrical device. Attached Figure Description

[0038] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application;

[0040] Figure 2 is an exploded view of a battery provided in some embodiments of this application;

[0041] Figure 3 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0042] Figure 4 is an exploded view of a single battery cell provided in some embodiments of this application;

[0043] Figure 5 is a top view of a single battery cell provided in some embodiments of this application;

[0044] Figure 6 is a cross-sectional view of position AA in Figure 5;

[0045] Figure 7 is an enlarged view of position B in Figure 6;

[0046] Figure 8 is a schematic diagram of the structure of a battery cell provided in some other embodiments of this application;

[0047] Figure 9 is a top view of a battery cell provided in some other embodiments of this application;

[0048] Figure 10 is a cross-sectional view at position CC in Figure 9;

[0049] Figure 11 is an enlarged view of position D in Figure 10.

[0050] Icons: 10-Box; 11-First part; 12-Second part; 20-Battery cell; 21-Outer shell; 211-Housing shell; 212-End cap; 23-Wall; 231-Weak part; 232-Pressure relief groove; 24-Electrode terminal; 25-Electrode assembly; 251-First electrode lead-out; 2511-First tab; 2512-First current collector; 252-Second electrode lead-out; 2521-Second tab; 2522-Second current collector; 26-Lower plastic; 28-Soldering part; 29-Insulating part; 100-Battery; 200-Controller; 300-Motor; 1000-Vehicle. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0052] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0053] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0054] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0055] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0056] In the embodiments of this application, the same reference numerals denote 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 thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0057] In this application, "multiple" means two or more (including two).

[0058] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0059] The battery cell can 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 the embodiments of this application are not limited to this.

[0060] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, helps prevent short circuits to some extent while allowing active ions to pass through.

[0061] In some embodiments, the positive electrode can be a positive electrode sheet, which may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0062] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0063] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0064] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this 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 in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM)622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0065] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0066] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative current collector.

[0067] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, nickel, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0068] As an example, the negative electrode sheet may include a negative current collector and a negative active material disposed on at least one surface of the negative current collector.

[0069] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0070] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. 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 alone or in combination of two or more.

[0071] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0072] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0073] In some embodiments, the separator is a separator membrane. The separator membrane can be of various types, and any known porous separator membrane with good chemical and mechanical stability can be selected.

[0074] As an example, the material of the separator may include at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes.

[0075] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0076] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Liquid electrolytes include electrolyte salts and solvents.

[0077] In some embodiments, the electrolyte salt may include 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 difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0078] In some embodiments, the solvent may include at least one selected from ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl 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, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more selected from ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0079] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0080] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0081] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0082] As an example, inorganic solid electrolytes may include 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 superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0083] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0084] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0085] In some implementations, the electrode assembly is a stacked structure.

[0086] As an example, multiple positive and negative electrode plates can be set, and multiple positive and multiple negative electrode plates can be stacked alternately.

[0087] As an example, multiple positive electrode sheets can be set, and negative electrode sheets are folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0088] As an example, both the positive and negative electrode sheets are folded to form multiple stacked folded segments.

[0089] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0090] As an example, the separator can be continuously arranged between any adjacent positive or negative electrode plates by folding or rolling.

[0091] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0092] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0093] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0094] In some embodiments, the housing can be a sealed structure or a non-sealed structure. As an example, when the housing is a sealed structure, it can protect the electrode assembly and prevent, to some extent, electrolyte leakage. When the housing is a non-sealed structure, it can still protect the electrode assembly, and a sealing bag may be included between the housing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag can be a bag-shaped insulating component or an aluminum-plastic film.

[0095] As an example, a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include, but are not limited to, square battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries.

[0096] The battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity.

[0097] In some embodiments, the battery can be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0098] In some embodiments, the battery can be a battery pack, which includes a housing and individual battery cells, with the individual battery cells or battery modules housed within the housing.

[0099] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0100] In some embodiments, the battery can be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0101] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0102] The development of battery technology must consider multiple design factors simultaneously, such as battery life, discharge capacity, and charge / discharge rate. Additionally, battery energy density also needs to be considered. However, current batteries have relatively low energy density.

[0103] In existing technologies, a single battery cell includes a positive electrode terminal and a negative electrode terminal. The positive electrode terminal is electrically connected to a positive tab, and the negative electrode terminal is electrically connected to a negative tab, to output electrical energy to or input electrical energy to the electrode assembly. Multiple electrode terminals occupy a significant amount of internal space in the battery, leading to a reduction in the battery's energy density.

[0104] Therefore, this application provides a battery cell including a casing, an electrode assembly, and electrode terminals. The casing has a wall portion, and the electrode assembly is housed within the casing. The electrode assembly includes a first electrode lead and a second electrode lead, with opposite polarities. The first electrode lead is electrically connected to the wall portion, and the electrode terminals are insulated and mounted on the wall portion, and are electrically connected to the second electrode lead.

[0105] The first electrode lead is electrically connected to the wall, and the second electrode lead is electrically connected to the electrode terminal. This allows for the output or input of electrical energy to the electrode assembly via the wall and electrode terminals. On one hand, this reduces the number of electrode terminals required, lowering costs, reducing the space occupied within the battery, and increasing energy density. On the other hand, once the information acquisition device is electrically connected to the wall, it can collect usage information from individual battery cells. This facilitates the connection of the information acquisition device to individual battery cells and data collection, reducing the difficulty of data collection from individual battery cells and further lowering manufacturing costs.

[0106] The technical solutions described in the embodiments of this application are applicable to batteries and electrical devices that use batteries.

[0107] Electrical equipment can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, including but not limited to electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.

[0108] For ease of explanation, the following embodiments will use a vehicle 1000 as an example of electrical equipment.

[0109] Please refer to Figure 1, which is a structural schematic diagram of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery 100 is disposed inside the vehicle 1000, and the battery 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000; for example, the battery 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during startup, navigation, and driving.

[0110] In some embodiments of this application, the battery 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0111] Please refer to Figure 2, which is an exploded view of a battery 100 provided in some embodiments of this application. The battery 100 includes a housing 10 and a battery cell 20, with the battery cell 20 housed within the housing 10. The housing 10 provides a space for the battery cell 20 and can have various structures. In some embodiments, the housing 10 may include a first portion 11 and a second portion 12, which overlap each other, jointly defining a space for accommodating the battery cell 20. The second portion 12 may be a hollow structure with one open end, and the first portion 11 may be a plate-like structure, covering the open side of the second portion 12 so that the first portion 11 and the second portion 12 jointly define the space. Alternatively, the first portion 11 and the second portion 12 may both be hollow structures with one open side, with the open side of the first portion 11 covering the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 can have various shapes, such as a cylinder, a cuboid, etc.

[0112] In battery 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, battery 100 can also be composed of multiple battery cells 20 first connected in series, parallel, or in a mixed manner to form a battery module, and then multiple battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within the housing 10. Battery 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 20.

[0113] Each battery cell 20 can be a secondary battery cell or a primary battery cell; it can also be a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, but is not limited to these. The battery cell 20 can be cylindrical, flat, cuboid, or other shapes.

[0114] Please refer to Figures 3, 4, 5, 6, and 7. Figure 3 is a structural schematic diagram of a battery cell 20 provided in some embodiments of this application. Figure 4 is an exploded view of a battery cell 20 provided in some embodiments of this application. Figure 5 is a top view of a battery cell 20 provided in some embodiments of this application. Figure 6 is a cross-sectional view at position AA in Figure 5. Figure 7 is an enlarged view at position B in Figure 6. This application provides a battery cell 20, which includes a housing 21, an electrode assembly 25, and electrode terminals 24. The housing 21 has a wall portion 23, and the electrode assembly 25 is housed within the housing 21. The electrode assembly 25 includes a first electrode lead-out portion 251 and a second electrode lead-out portion 252, with opposite polarities. The first electrode lead-out portion 251 is electrically connected to the wall portion 23, and the electrode terminals 24 are insulated and mounted on the wall portion 23, and are electrically connected to the second electrode lead-out portion 252.

[0115] Battery cell 20 refers to the smallest unit that makes up battery 100.

[0116] The housing 21 includes a housing 211 and an end cap 212. The housing 211 has a receiving space with an opening at one end for accommodating the electrode assembly 25. The end cap 212 is connected to the housing 211 and closes the opening.

[0117] End cap 212 refers to a component that covers the opening of housing 211 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 212 can be adapted to the shape of housing 211 to fit it. Optionally, end cap 212 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 212 is not easily deformed under pressure and impact, giving battery cell 20 higher structural strength and improved reliability. The material of end cap 212 can also include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. Battery cell 20 also includes lower plastic 26, which is disposed inside end cap 212. Lower plastic 26 can be used to isolate electrical connection components inside housing 211 from end cap 212 to reduce the risk of short circuit. For example, lower plastic 26 can be plastic, rubber, etc.

[0118] The housing 211 is a component used to cooperate with the end cap 212 to form the internal environment of the battery cell 20. This internal environment can accommodate the electrode assembly 25, electrolyte, and other components. The housing 211 and the end cap 212 can be independent components. An opening can be provided on the housing 211, and the end cap 212 can be used to close the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 212 and the housing 211 can be integrated. Specifically, the end cap 212 and the housing 211 can form a common mating surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 211, the end cap 212 closes the housing 211. The housing 211 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 211 can be determined according to the specific shape and size of the electrode assembly 25. The material of the housing 211 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0119] The wall portion 23 can be an end cap 212 of the outer casing 21, or it can be a wall of the housing 211 of the outer casing 21. In some embodiments, as shown in Figures 3 and 4, the wall portion 23 is an end cap 212. In other embodiments, the wall portion 23 can be a bottom wall of the housing 211 opposite to the end cap 212. In still other embodiments, the wall portion 23 can also be a side wall of the housing 211 adjacent to and connected to the end cap 212.

[0120] Electrode assembly 25 is the component in the battery cell 20 where electrochemical reactions occur. The casing 21 may contain one or more electrode assemblies 25. The electrode assembly 25 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of the electrode assembly 25, while the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or separately at both ends. During the charging and discharging process of the battery 100, the positive and negative active materials react with the electrolyte.

[0121] The first electrode lead-out portion 251 is a structure used to draw electrical energy from the main body or introduce electrical energy into the main body. The first electrode lead-out portion 251 includes a first tab 2511, which is either a positive or negative tab as described above. The first tab 2511 can be directly connected to the wall portion 23. In other embodiments, the first electrode lead-out portion 251 may also include other electrical connection components connected to the first tab 2511. For example, the first electrode lead-out portion 251 may also include a first current collector 2512, which connects the first tab 2511 and the wall portion 23 to guide the electrical energy of the electrode assembly 25 to the wall portion 23 or receive electrical energy introduced from the wall portion 23.

[0122] The first tab 2511 can be either a positive or a negative tab. When the first tab 2511 is a positive tab, the wall portion 23 serves as the positive electrode of the battery cell 20. When the first tab 2511 is a negative tab, the wall portion 23 serves as the negative electrode of the battery cell 20.

[0123] The first electrode lead-out portion 251 can be used to determine which wall of the outer casing 21 is wall portion 23. For example, when the first electrode lead-out portion 251 is connected to the end cap 212, then the end cap 212 is wall portion 23. When the first electrode lead-out portion 251 is connected to the bottom wall of the casing 211, then the bottom wall is wall portion 23. When the first electrode lead-out portion 251 is connected to the side wall of the casing 211, then the side wall is wall portion 23.

[0124] Electrode terminal 24 is used for electrical connection with the tab of electrode assembly 25 to input or output electrical energy of battery cell 20. Electrode terminal 24 and tab can be directly connected, for example, by direct soldering. Electrode terminal 24 and tab can also be indirectly connected, for example, by indirect connection through current collector.

[0125] The electrode terminal 24 is insulated from the wall portion 23, meaning that the electrode terminal 24 is insulated from the wall portion 23. Optionally, the battery cell 20 includes an insulating member 29 disposed between the electrode terminal 24 and the wall portion 23 to insulate the electrode terminal 24 from the wall portion 23.

[0126] The second electrode lead-out portion 252 is a structure used to lead out electrical energy from the electrode assembly 25 or to introduce electrical energy into the electrode assembly 25. The second electrode lead-out portion 252 includes a second tab 2521, which can be either a negative or positive tab as described above, and can be directly connected to the electrode terminal 24. In other embodiments, the second electrode lead-out portion 252 may also include other electrical connection components connected to the second tab 2521. For example, the second electrode lead-out portion 252 may also include a second current collector 2522, which connects the second tab 2521 and the electrode terminal 24 to guide electrical energy from the electrode assembly 25 to the electrode terminal 24 or receive electrical energy introduced from the electrode terminal 24.

[0127] The first electrode lead 251 and the second electrode lead 252 have opposite polarities. For example, when the first electrode lead 251 is a positive electrode lead, the second electrode lead 252 is a negative electrode lead. When the first electrode lead 251 is a negative electrode lead, the second electrode lead 252 is a positive electrode lead. Correspondingly, the first electrode tab 2511 and the second electrode tab 2521 have opposite polarities. For example, when the first electrode tab 2511 is a positive electrode tab, the second electrode tab 2521 is a negative electrode tab. When the first electrode tab 2511 is a negative electrode tab, the second electrode tab 2521 is a positive electrode tab.

[0128] The first electrode lead-out portion 251 is electrically connected to the wall portion 23, and the second electrode lead-out portion 252 is electrically connected to the electrode terminal 24. This allows for the output or input of electrical energy to the electrode assembly 25 via the wall portion 23 and the electrode terminal 24. On one hand, this reduces the number of electrode terminals 24 required, lowering costs, reducing the space occupied within the battery 100, and increasing energy density. On the other hand, once the information acquisition device is electrically connected to the wall portion 23, it can collect usage information from the battery cell 20. This facilitates the connection of the information acquisition device to the battery cell 20 and data acquisition, reducing the difficulty of data acquisition from the battery cell 20 and further lowering manufacturing costs.

[0129] Referring to Figures 3, 4, 5, 6, and 7, in some embodiments, the first electrode lead-out portion 251 is welded to the wall portion 23 to form a solder mark portion 28. The battery cell 20 includes a pressure relief mechanism disposed on the wall portion 23. The pressure relief mechanism includes a weak portion 231, configured to split along at least a portion of the weak portion 231 when the battery cell 20 is depressurized. The weak portion 231 is disposed between the solder mark portion 28 and the electrode terminal 24 in a direction perpendicular to the thickness direction of the wall portion 23.

[0130] The solder mark 28 is the solder mark 28 left after welding the first electrode lead-out portion 251 and the wall portion 23. The welding method is not limited, for example, gas welding, electric welding, laser welding, etc.

[0131] The pressure relief mechanism is a component used to open when the internal pressure or temperature of the battery cell 20 reaches the explosion pressure, thereby releasing the internal pressure of the battery cell 20. The pressure relief mechanism is disposed on the wall portion 23. The pressure relief mechanism can be a component mounted on the wall portion 23, in which case the pressure relief mechanism and the wall portion 23 are separately disposed but connected. For example, the pressure relief mechanism is an explosion-proof plate mounted on the wall portion 23. The pressure relief mechanism can also be part of the wall portion 23, in which case the pressure relief mechanism and the wall portion 23 are integrally formed.

[0132] The weak portion 231 serves a pressure relief function, allowing the pressure relief mechanism to crack along the weak portion 231 when the internal pressure or temperature of the battery cell 20 reaches a predetermined value, thereby releasing the internal pressure of the battery cell 20. In some embodiments, the strength of the pressure relief mechanism at the weak portion 231 may be lower than the strength at other locations of the pressure relief mechanism, so that the weak portion 231 can crack under the internal pressure when the internal pressure or temperature of the battery cell 20 reaches the predetermined value, thereby releasing the internal pressure of the battery cell 20. In other embodiments, the melting point of the pressure relief mechanism at the weak portion 231 may be lower than the melting point at other locations of the pressure relief mechanism. Thus, when the internal pressure or temperature of the battery cell 20 reaches the predetermined value, the weak portion 231 can crack under the high temperature, thereby releasing the internal pressure of the battery cell 20.

[0133] A weak point 231 is disposed between the solder portion 28 and the electrode terminal 24 in a direction perpendicular to the thickness direction of the wall portion 23. Referring to Figures 6 and 7, the thickness direction of the wall portion 23 is the X direction shown in the figures. The direction perpendicular to the thickness direction of the wall portion 23 is the Y direction shown in the figures. In the embodiment shown in Figures 6 and 7, the battery cell 20 is a cylindrical battery cell, and the wall portion 23 is an end cap 212. The direction perpendicular to the thickness direction of the wall portion 23 is the radial direction of the end cap 212.

[0134] By providing a pressure relief mechanism, the mechanism can crack along at least a portion of the weak section 231 when the battery cell 20 is depressurized, thereby releasing the internal pressure of the battery cell 20. The weak section 231 is positioned between the solder portion 28 and the electrode terminal 24 in a direction perpendicular to the thickness direction of the wall portion 23, so that when the weak section 231 cracks, it can open a larger opening, which is beneficial for the rapid depressurization of the battery cell 20.

[0135] Referring to Figures 3, 4, 5, 6, and 7, in some embodiments, the weak portion 231 is an annular structure surrounding the electrode terminal 24. Along a direction perpendicular to the thickness direction of the wall portion 23, the minimum distance between the weak portion 231 and the solder mark portion 28 is less than the minimum distance between the weak portion 231 and the electrode terminal 24.

[0136] The weak portion 231 has a ring-shaped structure and is a closed shape extending along a closed trajectory. For example, the weak portion 231 can be a circular, elliptical, square, hexagonal, or other closed shape. The electrode terminal 24 is disposed on the inner side of the weak portion 231.

[0137] Referring to Figure 7, the minimum distance A between the weak portion 231 and the solder joint 28 along the direction perpendicular to the thickness direction of the wall portion 23, and the minimum distance B between the weak portion 231 and the electrode terminal 24 along the direction perpendicular to the thickness direction of the wall portion 23, satisfying that A < B. In short, the weak portion 231 is disposed between the solder joint 28 and the electrode terminal 24 along the direction perpendicular to the thickness direction of the wall portion 23, and the weak portion 231 is disposed close to the solder joint 28.

[0138] The weak portion 231 is an annular structure surrounding the electrode terminal 24. The weak portion 231 divides the pressure relief mechanism into two parts, one part located on the outside of the weak portion 231 and the other part located on the inside of the weak portion 231. In the direction perpendicular to the thickness of the wall portion 23, by making the minimum distance between the weak portion 231 and the solder mark portion 28 smaller than the minimum distance between the weak portion 231 and the electrode terminal 24, that is, by setting the weak portion 231 close to the solder mark portion 28, when the battery cell 20 is depressurized, the part of the pressure relief mechanism located on the inside of the weak portion 231 is subjected to a greater force from the gas. The part of the pressure relief mechanism located on the inside of the weak portion 231 can open to relieve pressure, forming a larger opening for gas to escape. The pressure relief area of ​​the battery cell 20 is larger when it is depressurized, which is beneficial for the rapid depressurization of the battery cell 20.

[0139] Please refer to Figures 8, 9, 10, and 11. Figure 8 is a structural schematic diagram of the battery cell 20 provided in some embodiments of this application. Figure 9 is a top view of the battery cell 20 provided in some embodiments of this application. Figure 10 is a cross-sectional view at position CC in Figure 9. Figure 11 is an enlarged view at position D in Figure 10. In some embodiments, the weak portion 231 is an annular structure surrounding the electrode terminal 24. Along the direction perpendicular to the thickness direction of the wall portion 23, the minimum distance between the weak portion 231 and the solder mark portion 28 is greater than the minimum distance between the weak portion 231 and the electrode terminal 24.

[0140] Referring to Figure 11, the minimum distance A between the weak portion 231 and the solder joint 28 along the direction perpendicular to the thickness direction of the wall portion 23, and the minimum distance B between the weak portion 231 and the electrode terminal 24 along the direction perpendicular to the thickness direction of the wall portion 23, satisfying that A > B. In short, the weak portion 231 is disposed between the solder joint 28 and the electrode terminal 24 along the direction perpendicular to the thickness direction of the wall portion 23, and the weak portion 231 is disposed close to the electrode terminal 24.

[0141] The weak portion 231 is an annular structure surrounding the electrode terminal 24. The weak portion 231 divides the pressure relief mechanism into two parts, one part located on the outside of the weak portion 231 and the other part located on the inside of the weak portion 231. In the direction perpendicular to the thickness direction of the wall portion 23, by making the minimum distance between the weak portion 231 and the solder mark portion 28 greater than the minimum distance between the weak portion 231 and the electrode terminal 24, that is, by setting the weak portion 231 close to the electrode terminal 24, when the battery cell 20 is depressurized, the part of the pressure relief mechanism located on the outside of the weak portion 231 is subjected to a greater force from the gas, and the part of the pressure relief mechanism located on the outside of the weak portion 231 can open to release pressure, making it less likely for the electrode terminal 24 to detach from the wall portion 23 and less likely to come into contact with other electrical connection components and cause a short circuit.

[0142] Please refer to Figures 3, 4, 5, 6 and 7. In some embodiments, the minimum distance between the weak portion 231 and the solder mark portion 28 along the direction perpendicular to the thickness direction of the wall portion 23 is A, which satisfies: A≥3mm.

[0143] The minimum distance between the weak part 231 and the solder mark 28 in the direction perpendicular to the thickness of the wall part 23 can be: A = 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, etc.

[0144] By ensuring that the minimum distance between the weak portion 231 and the solder mark 28 in the direction perpendicular to the thickness of the wall portion 23 is greater than or equal to 3 mm, it is beneficial to reduce the impact of high heat on the weak portion 231 when welding the first electrode lead-out portion 251 and the wall portion 23, thereby reducing the risk of premature cracking of the weak portion 231 and improving the lifespan of the battery cell 20.

[0145] Please refer to Figures 3, 4, 5, 6 and 7. In some embodiments, along the direction perpendicular to the thickness of the wall portion 23, the minimum distance between the weak portion 231 and the electrode terminal 24 is B, which satisfies: B≥4mm.

[0146] The minimum distance between the weak part 231 and the electrode terminal 24 along the direction perpendicular to the thickness of the wall part 23 can be: B = 4mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, 5mm, etc.

[0147] By making the minimum distance between the weak part 231 and the electrode terminal 24 in the direction perpendicular to the thickness of the wall 23 greater than or equal to 4mm, the distance between the weak part 231 and the electrode unit is larger, which can reduce the inhibitory effect of the electrode terminal 24 on the deformation of the weak part 231, thereby facilitating the timely cracking of the weak part 231 when the battery cell 20 is depressurized, and improving the timeliness of depressurization of the battery cell 20.

[0148] Referring to Figures 3, 4, 5, 6 and 7, in some embodiments, the solder mark 28 and the weak point 231 are both annular structures surrounding the electrode terminal 24.

[0149] The solder mark portion 28 has a ring structure and is a closed shape extending along a closed trajectory. For example, the solder mark portion 28 can be a circular, elliptical, square, hexagonal, or other closed shape. The electrode terminal 24 is disposed on the inner side of the solder mark portion 28.

[0150] The solder mark 28 has a ring-shaped structure and is arranged around the outside of the electrode terminal 24. In this way, the first electrode lead-out portion 251 can be stably connected to the wall portion 23 and has a large current-passing area. By making the weak portion 231 into a ring-shaped structure, when the battery cell 20 is depressurized, the depressurization mechanism can split along the weak portion 231, thereby opening a larger opening to facilitate rapid depressurization of the battery cell 20.

[0151] Please refer to Figures 3, 4, 5, 6 and 7. In some embodiments, the pressure relief mechanism is provided with a pressure relief groove 232, and the pressure relief mechanism forms a weak part 231 in the area where the pressure relief groove 232 is provided.

[0152] The pressure relief mechanism has a first surface and a second surface disposed opposite to each other in the thickness direction of the wall portion 23. The first surface is provided with a pressure relief groove 232, that is, the pressure relief groove 232 is recessed from the first surface toward the second surface.

[0153] Along the thickness direction of the wall portion 23, the weak portion 231 is the part of the pressure relief mechanism located between the bottom surface of the pressure relief groove 232 furthest from the first surface and the second surface.

[0154] The pressure relief groove 232 can be formed in various ways, such as stamping or cold heading. Taking the stamping method as an example, the pressure relief groove 232 can be stamped on the pressure relief mechanism along the direction from the first surface to the second surface.

[0155] By using stamping or cold forging to form the pressure relief groove 232, the groove wall of the pressure relief groove 232 undergoes work hardening (the grain arrangement changes, leading to lattice distortion, reducing the metal's plasticity, and increasing the material's hardness), thus enhancing its resistance to external impacts and making it less susceptible to damage from external impacts. This helps reduce the risk of leakage from the pressure relief mechanism.

[0156] The weak part 231 is formed by opening a pressure relief groove 232 on the pressure relief mechanism, which is simple, convenient and low cost.

[0157] Please refer to Figures 3, 4, 5, 6 and 7. In some embodiments, the pressure relief groove 232 is disposed on the surface of the pressure relief mechanism away from the interior of the housing 21.

[0158] The first surface is the surface of the pressure relief mechanism that faces away from the inside of the outer casing 21, and the second surface is the surface of the pressure relief mechanism that faces the inside of the outer casing 21.

[0159] The first surface is the surface of the pressure relief mechanism that faces away from the interior of the housing 21, i.e., the outer surface of the pressure relief mechanism. The second surface is the surface of the pressure relief mechanism that faces the interior of the housing 21, i.e., the inner surface of the pressure relief mechanism. In short, the pressure relief groove 232 is provided on the outer surface of the pressure relief mechanism.

[0160] By setting the pressure relief groove 232 on the surface of the pressure relief mechanism away from the inside of the housing 211, the tension that the weak part 231 needs to overcome when it cracks is smaller, making it easier to crack.

[0161] Referring to Figures 3, 4, 5, 6 and 7, in some embodiments, the first electrode lead-out portion 251 includes a first electrode tab 2511 and a first current collector 2512. The first current collector 2512 is electrically connected to the first electrode tab 2511 and the wall portion 23. The first current collector 2512 is welded to the wall portion 23 to form a solder mark portion 28.

[0162] When the first electrode lead-out portion 251 includes the first current collector 2512, the first current collector 2512 is electrically connected to the first electrode tab 2511 and the wall portion 23, and the solder mark portion 28 is the solder mark portion 28 left after the first current collector 2512 and the wall portion 23 are soldered.

[0163] By setting the first current collector 2512, it is easier to realize the electrical connection between the first electrode tab 2511 and the wall portion 23, and the connection difficulty between the electrode assembly 25 and the wall portion 23 is reduced.

[0164] Referring to Figures 3, 4, 5, 6, and 7, in some embodiments, the first current collector 2512 and the wall portion 23 are arranged along the thickness direction of the wall portion 23. The wall portion 23 and the first current collector 2512 are welded together, and a portion of the solder mark 28 protrudes from the surface of the wall portion 23 away from the interior of the outer casing 21.

[0165] During penetration welding, the wall portion 23 and the first current collector 2512 can be welded along the direction from the wall portion 23 to the first current collector 2512, so that the weld mark portion 28 can be directly observed on the outer surface of the wall portion 23.

[0166] The connection between the first current collector 2512 and the wall portion 23 is achieved by through welding, which is simple, convenient, and produces high-quality welds. Furthermore, during through welding, the welding direction is approximately perpendicular to the thickness direction of the wall portion 23, which reduces the impact on the weak portion 231, lowers the risk of premature cracking of the weak portion 231, and helps to improve the lifespan of the battery cell 20.

[0167] Please refer to Figures 3, 4, 5, 6 and 7. In some embodiments, the pressure relief mechanism is integrally formed with the wall portion 23.

[0168] One-piece molding means that the wall portion 23 and the pressure relief mechanism are provided as a single structure. For example, the pressure relief mechanism can be formed on the wall portion 23 by means of stamping or cold forging.

[0169] The pressure relief mechanism is integrally formed with the wall 23, eliminating the need for additional welding or bonding processes, which helps reduce the risk of leakage from the pressure relief mechanism. Furthermore, during production, it is easier to ensure that the detonation pressure of multiple battery cells 20 produced is more consistent.

[0170] In other embodiments, the pressure relief mechanism is separately disposed from the wall portion 23, the wall portion 23 is provided with a pressure relief hole, and the pressure relief mechanism is installed on the wall portion 23 and covers the pressure relief hole.

[0171] The phrase "the pressure relief mechanism and wall portion 23 are separately configured, the wall portion 23 is provided with a pressure relief hole, and the pressure relief mechanism is installed on the wall portion 23 and covers the pressure relief hole" means that during manufacturing, a pressure relief hole is provided on the wall portion 23, and the pressure relief mechanism and wall portion 23 are provided separately and ultimately connected together. For example, the pressure relief mechanism can be welded to the wall portion 23. The pressure relief mechanism can be an explosion-proof plate installed on the wall portion 23.

[0172] The pressure relief mechanism is separately set and installed on the wall portion 23 to facilitate manufacturing.

[0173] Referring to Figures 3, 4, 5, 6, and 7, in some embodiments, the first electrode lead-out portion 251 includes a first tab 2511, and the second electrode lead-out portion 252 includes a second tab 2521. Along the thickness direction of the wall portion 23, the first tab 2511 and the second tab 2521 are formed at the same end of the electrode assembly 25.

[0174] Please refer to Figure 4. In the embodiment shown in Figure 4, both the first tab 2511 and the second tab 2521 are formed on the upper end of the electrode assembly 25.

[0175] By forming the first tab 2511 and the second tab 2521 at the same end of the electrode assembly 25, it is simpler and more convenient to electrically connect the first tab 2511 to the wall portion 23 and the second tab 2521 to the electrode terminal 24, which helps to reduce manufacturing costs.

[0176] Referring to Figures 3, 4, 5, 6, and 7, in some embodiments, the housing 21 includes a housing 211 and an end cap 212. The housing 211 has a receiving space with an opening at one end for accommodating the electrode assembly 25. The end cap 212 is connected to the housing 211 and closes the opening. The end cap 212 is a wall portion 23.

[0177] When the end cap 212 is a wall portion 23, the first electrode lead-out portion 251 is connected to the end cap 212, and the electrode terminal 24 is disposed on the end cap 212, making manufacturing simple and convenient.

[0178] Please refer to Figures 3, 4, 5, 6 and 7. In some embodiments, the battery cell 20 is a cylindrical battery cell.

[0179] This application embodiment also provides a battery 100, which includes the battery cell 20 described above.

[0180] This application embodiment also provides an electrical device, which includes the aforementioned battery cell 20, and the battery cell 20 is used to provide electrical energy to the electrical device.

[0181] Please refer to Figures 3 to 11 for some embodiments of this application.

[0182] This application provides a battery cell 20, which includes a housing 21, an electrode assembly 25, and electrode terminals 24. The housing 21 has a wall 23, and the electrode assembly 25 is housed within the housing 21. The electrode assembly 25 includes a first electrode lead-out portion 251 and a second electrode lead-out portion 252, with opposite polarities. The first electrode lead-out portion 251 is electrically connected to the wall 23, and the electrode terminals 24 are insulated and mounted on the wall 23, and electrically connected to the second electrode lead-out portion 252. The electrical connection between the first electrode lead-out portion 251 and the wall 23, and the electrical connection between the second electrode lead-out portion 252 and the electrode terminals 24, allows for the output or input of electrical energy to the electrode assembly 25 via the wall 23 and the electrode terminals 24. This reduces the number of electrode terminals 24 required, lowers costs, reduces the space occupied within the battery 100, and increases energy density. On the other hand, once the information acquisition device is electrically connected to the wall 23, it can collect the usage information of the battery cell 20, which facilitates the connection of the information acquisition device to the battery cell 20 and the collection of data. This helps to reduce the difficulty of data collection by the battery cell 20 and further reduce the cost of production and manufacturing.

[0183] The first electrode lead-out portion 251 is welded to the wall portion 23 to form a solder mark portion 28. The battery cell 20 includes a pressure relief mechanism disposed on the wall portion 23. The pressure relief mechanism includes a weak portion 231, configured to split along at least a portion of the weak portion 231 when the battery cell 20 is depressurized. The weak portion 231 is disposed between the solder mark portion 28 and the electrode terminal 24 in a direction perpendicular to the thickness direction of the wall portion 23. By providing the pressure relief mechanism, it can split along at least a portion of the weak portion 231 when the battery cell 20 is depressurized, thereby releasing the internal pressure of the battery cell 20. The weak portion 231 is disposed between the solder mark portion 28 and the electrode terminal 24 in a direction perpendicular to the thickness direction of the wall portion 23, allowing for a larger opening when the weak portion 231 splits, which facilitates rapid pressure relief of the battery cell 20.

[0184] In some embodiments, the weak portion 231 is an annular structure surrounding the electrode terminal 24. Along the direction perpendicular to the thickness of the wall portion 23, the minimum distance between the weak portion 231 and the solder mark 28 is less than the minimum distance between the weak portion 231 and the electrode terminal 24. By making the minimum distance between the weak portion 231 and the solder mark 28 less than the minimum distance between the weak portion 231 and the electrode terminal 24, i.e., by placing the weak portion 231 close to the solder mark 28, when the battery cell 20 is depressurized, the area inside the weak portion 231 experiences a greater gas force, allowing the area inside the weak portion 231 to open and form a larger opening for gas discharge. This results in a larger depressurization area for the battery cell 20, which is beneficial for rapid depressurization of the battery cell 20.

[0185] In other embodiments, the weak portion 231 is an annular structure surrounding the electrode terminal 24. Along the direction perpendicular to the thickness of the wall portion 23, the minimum distance between the weak portion 231 and the solder mark 28 is greater than the minimum distance between the weak portion 231 and the electrode terminal 24. By making the minimum distance between the weak portion 231 and the solder mark 28 greater than the minimum distance between the weak portion 231 and the electrode terminal 24, i.e., by placing the weak portion 231 close to the electrode terminal 24, when the battery cell 20 is depressurized, the area outside the weak portion 231 experiences a greater force from the gas, allowing the area outside the weak portion 231 to open. This makes it less likely for the electrode terminal 24 to detach from the wall portion 23 and less likely to come into contact with other electrical connection components, thus preventing a short circuit.

[0186] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, wherein, include: The outer shell has walls; An electrode assembly is housed within the housing. The electrode assembly includes a first electrode lead-out portion and a second electrode lead-out portion. The first electrode lead-out portion and the second electrode lead-out portion have opposite polarities. The first electrode lead-out portion is welded to the wall portion to form a solder mark portion. An electrode terminal is insulated and mounted on the wall portion, and the electrode terminal is electrically connected to the second electrode lead-out portion; A pressure relief mechanism is disposed on the wall portion, the pressure relief mechanism including a weak portion, the weak portion being configured to at least partially crack when the battery cell is depressurized; Along a direction perpendicular to the thickness direction of the wall portion, the weak portion is disposed between the solder mark portion and the electrode terminal.

2. The battery cell according to claim 1, wherein, The weak portion is an annular structure surrounding the electrode terminal. Along the direction perpendicular to the thickness of the wall portion, the minimum distance between the weak portion and the solder mark is less than the minimum distance between the weak portion and the electrode terminal.

3. The battery cell according to claim 1, wherein, The weak portion is an annular structure surrounding the electrode terminal. Along the direction perpendicular to the thickness of the wall portion, the minimum distance between the weak portion and the solder mark is greater than the minimum distance between the weak portion and the electrode terminal.

4. The battery cell according to any one of claims 1-3, wherein, Along the direction perpendicular to the thickness of the wall portion, the minimum distance between the weak portion and the solder mark portion is A, which satisfies: A≥3mm.

5. The battery cell according to any one of claims 1-4, wherein, Along the direction perpendicular to the thickness of the wall, the minimum distance between the weak part and the electrode terminal is B, which satisfies: B≥4mm.

6. The battery cell according to any one of claims 1-5, wherein, Both the solder mark portion and the weak portion are annular structures arranged around the electrode terminal.

7. The battery cell according to any one of claims 1-6, wherein, The pressure relief mechanism is provided with a pressure relief groove, and the pressure relief mechanism forms the weak part in the area where the pressure relief groove is provided.

8. The battery cell according to claim 7, wherein, The pressure relief groove is located on the surface of the pressure relief mechanism that is away from the interior of the outer casing.

9. The battery cell according to any one of claims 1-8, wherein, The first electrode lead-out portion includes a first electrode tab and a first current collector, the first current collector being electrically connected to the first electrode tab and the wall portion, and the first current collector being welded to the wall portion to form the solder mark portion.

10. The battery cell according to claim 9, wherein, The first current collector and the wall portion are arranged along the thickness direction of the wall portion, and the wall portion and the first current collector are welded through each other, with a portion of the weld mark protruding from the surface of the wall portion away from the interior of the outer casing.

11. The battery cell according to any one of claims 1-10, wherein, The pressure relief mechanism is integrally formed with the wall portion.

12. The battery cell according to any one of claims 1-10, wherein, The pressure relief mechanism is separately disposed from the wall portion, the wall portion is provided with a pressure relief hole, and the pressure relief mechanism is installed on the wall portion and covers the pressure relief hole.

13. The battery cell according to any one of claims 1-12, wherein, The first electrode lead-out portion includes a first tab, and the second electrode lead-out portion includes a second tab. Along the thickness direction of the wall portion, the first tab and the second tab are formed at the same end of the electrode assembly.

14. The battery cell according to any one of claims 1-13, wherein, The outer casing includes: The housing has an open-end receiving space for accommodating the electrode assembly; End cap, connected to the housing and closing the opening; The end cap is the wall portion.

15. The battery cell according to any one of claims 1-14, wherein, The battery cell is a cylindrical battery cell.

16. A battery, wherein, Includes the battery cell according to any one of claims 1-15.

17. An electrical appliance, wherein, Includes a battery cell according to any one of claims 1-15, the battery cell being used to provide electrical energy to the electrical equipment.

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