Battery cell, connecting member, battery device, and electric device

Abstract

Embodiments of the present application disclose a battery cell, a connecting member, a battery device, and an electric device. The battery cell comprises: a casing having an accommodating cavity; a first electrode terminal arranged in the housing; an electrode assembly arranged in the accommodating cavity, the electrode assembly comprising a main body portion and a first tab; and a connecting member, the connecting member comprising a first adapter component and a second adapter component, the first adapter component and the second adapter component being made of different materials, the first adapter component being connected to the second adapter component, the first adapter component being connected to the first tab, the first electrode terminal being connected to the second adapter component, and the first tab having the same polarity as the first electrode terminal, wherein the material of the first adapter component is the same as that of the first tab, the material of the second adapter component is the same as that of the first electrode terminal, and the density of the first adapter component is less than that of the second adapter component. Thus, the weight of the battery cell can be reduced.

Description

A battery cell, a connecting component, a battery device, and an electrical device. Technical Field

[0001] This application relates to the field of batteries, and more specifically, to a battery cell, a connecting member, a battery device, and an electrical device. Background Technology

[0002] The application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also widely used 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 the application fields of power batteries, the market demand is also constantly increasing. As a component of power batteries, the market demand for battery cells is also rising, for example, requiring lighter battery cells.

[0003] Therefore, how to reduce the weight of individual battery cells has become an urgent problem to be solved. Summary of the Invention

[0004] This application provides a battery cell, a connecting member, a battery device, and an electrical device, which can reduce the weight of the battery cell.

[0005] In a first aspect, this application provides a battery cell, comprising: a housing having a receiving cavity; a first electrode terminal disposed on the housing; an electrode assembly disposed on the receiving cavity, the electrode assembly including a main body and a first electrode tab connected to the main body; and a connecting member electrically connecting the first electrode terminal and the first electrode tab, the connecting member including a first adapter and a second adapter, the first adapter and the second adapter being made of different materials, the first adapter being connected to the second adapter, the first adapter being connected to the first electrode tab, the first electrode terminal being connected to the second adapter, and the first electrode tab and the first electrode terminal having the same polarity; wherein, the material of the first adapter is the same as the material of the first electrode tab, the material of the second adapter is the same as the material of the first electrode terminal, and the density of the first adapter is less than the density of the second adapter.

[0006] In the technical solution of this application embodiment, the density of the first adapter component used to connect the first tab is less than that of the second adapter component used to connect the first electrode terminal. The material of the first adapter component is the same as that of the first tab, and the material of the second adapter component is the same as that of the first electrode terminal. The first tab uses a lighter material than the first electrode terminal, which reduces the overall weight of the battery and is beneficial to the performance improvement of the battery cell. At the same time, the dissimilar material connection interface is located at the connecting component, which reduces the connection complexity of the dissimilar material tab and electrode terminal, simplifies the structure of the electrode terminal, and reduces the manufacturing cost of the electrode terminal.

[0007] In some embodiments, the first adapter and the second adapter are stacked along the thickness direction of the second adapter.

[0008] In this embodiment, the surface area of ​​the first adapter and the second adapter stacked along the thickness direction is large. The first adapter and the second adapter of the connecting member are stacked along the thickness direction of the second adapter, which can increase the contact area between the first adapter and the second adapter, improve the flow efficiency, and reduce the heat loss at the connecting member.

[0009] In some embodiments, the first adapter component and the second adapter component are connected in a solid-solid composite manner.

[0010] In some embodiments, the second adapter includes an electrode terminal connection area and a tab connection area, the electrode terminal connection area being connected to the first electrode terminal, and the tab connection area being connected to the first adapter.

[0011] In some embodiments, the first adapter is disposed on the side of the tab connection area facing the main body.

[0012] In this embodiment, the first adapter component is combined with the second adapter component at least a portion of the surface of the electrode connection area of ​​the second adapter component facing the first electrode tab. The first adapter component is not provided in the electrode terminal connection area, which reduces the composite area and reduces the composite cost.

[0013] In some embodiments, a portion of the first adapter is stacked with the tab connection area, and another portion is stacked with the electrode terminal connection area.

[0014] In this embodiment, the electrode terminal connection area and the tab connection area of ​​the first adapter component and the second adapter component are connected, maximizing the current flow area and improving the current flow efficiency.

[0015] In some embodiments, the second adapter further includes a transition region connecting the tab connection region and the electrode terminal connection region, wherein the tab connection region is further away from the main body than the electrode terminal connection region.

[0016] In this embodiment of the application, by setting a transition area, the second adapter can be fully extended within a limited space, so that the connecting member can make full use of the internal space of the battery cell, thereby improving the space utilization of the battery cell and increasing the energy density.

[0017] In some embodiments, the first adapter is connected to the end face of the second adapter along a first direction, wherein the first direction is perpendicular to the thickness direction of the second adapter.

[0018] In this embodiment, the first adapter component and the second adapter component are connected at the end face. When processing the adapter component, the profile of the large first adapter component and the profile of the large second adapter component can be combined and then physically or by laser cutting to cut into small connecting components. The processing technology is simple and saves processing costs.

[0019] In some embodiments, the first adapter includes a first sub-component and a second sub-component spaced apart.

[0020] Since the electrode assembly tab can be configured to be divided into two sub-parts, the area of ​​the first adapter component located between the two sub-parts of the tab does not need to be connected to the tab, thereby saving material in the middle part and reducing the material cost of the first adapter component.

[0021] In some embodiments, the first sub-component and the second sub-component extend along a second direction, wherein the second direction is perpendicular to the thickness direction of the second adapter.

[0022] In some embodiments, the second adapter includes an electrode terminal connection area and a tab connection area. The tab connection area includes a base plate and a protrusion structure disposed on the base plate. The first sub-component and the second sub-component are stacked with the base plate, and the protrusion structure is disposed between the first sub-component and the second sub-component.

[0023] In this embodiment, the two sub-components of the first adapter are stacked with the base plate of the electrode connection area, and a protruding structure is provided between the first sub-component and the second sub-component, which can improve the flow efficiency while saving the material cost of the first adapter.

[0024] In some embodiments, the first sub-component and the second sub-component are combined with the second adapter at at least a portion of the surface of the tab connection area facing the main body, and / or the first sub-component and the second sub-component are combined with the second adapter at the sidewalls of the protruding structure.

[0025] In this embodiment, the first sub-component and the second sub-component are disposed on the base plate of the second adapter in the tab connection area and located on both sides of the protrusion extending in the second direction. The first sub-component and the second sub-component can pass through the base plate and the side wall of the protrusion, thereby improving the flow efficiency.

[0026] In some embodiments, the density of the first adapter component is less than 5 g / cm3.

[0027] In this embodiment, the first tab connected to the connecting member can be a negative electrode tab, and the first electrode terminal can be a negative electrode terminal. Since metal ions (e.g., lithium ions) in the electrolyte migrate towards the negative electrode, to prevent corrosion or alloy formation, the negative electrode is generally made of an inert metal that is unlikely to form an alloy with the metal ions in the electrolyte. The commonly used negative electrode current collector is copper foil, which has a high density, resulting in a high overall battery weight and making it difficult to carry and transport. Therefore, using negative electrode tabs and the first adapter component 231, with densities lower than those of the negative electrode terminals, such as titanium and magnesium, helps to reduce the weight of the battery cell.

[0028] In some embodiments, the first adapter is made of titanium.

[0029] When selecting positive and / or negative electrode materials for battery cells, many factors need to be considered. Many light metals, such as sodium, magnesium, aluminum, and zinc, react with water in aqueous electrolytes, causing electrode corrosion and releasing hydrogen gas, which is detrimental to battery stability. In such cases, alternative electrolyte types or electrode modification may be necessary. Some light metals, such as aluminum and titanium, have low redox potentials (-1.663V and -1.63eV, respectively), readily forming a dense oxide film on their surface. Electron migration through this oxide film passivates the reaction between the metal within the oxide film and the solution. Therefore, in most cases, the electromotive force of these metals as electrodes is higher than their redox potential in their pure metallic state, making them suitable as electrodes. However, aluminum in electrolytes, due to its microstructure, may form alloys with metal ions in the solution. For example, aluminum's octet structure is similar to lithium, easily forming lithium-aluminum alloys, which may reduce the cycle capacity of the battery cell. This problem is more pronounced when aluminum is used as the negative electrode current collector. When titanium is used as the negative electrode current collector in a battery cell, there is no need to consider the issue of alloying with metals in the electrolyte. In summary, using titanium as the material for the first adapter component is beneficial for the stability of the battery cell electrodes, the stability of the electrolyte, and for maintaining the cycle capacity and lifespan of the battery cell.

[0030] In some embodiments, the second adapter is made of copper.

[0031] Copper possesses excellent electrical conductivity, corrosion resistance, and processability, meeting the requirements for battery electrode materials. Furthermore, copper can improve battery cycle life and capacity, while reducing internal resistance and voltage drop.

[0032] In some embodiments, the surface of the second adapter component away from the main body is provided with a blind hole.

[0033] In this embodiment, the blind hole can effectively reduce the thickness of the second adapter component on the bottom wall of the blind hole, and when connected by means such as through welding, the power of the laser and the difficulty of penetration can be reduced.

[0034] In some embodiments, the first electrode terminal is a negative electrode terminal, and the first tab is a negative tab.

[0035] Because metal ions (such as lithium ions) in the electrolyte migrate towards the negative electrode, an inert metal is typically used to prevent corrosion or alloy formation. This metal is also designed to resist alloying with the electrolyte ions. The commonly used negative electrode current collector is copper foil, which has a high density, resulting in a heavy battery that is difficult to carry and transport. Therefore, using negative electrode tabs and the first adapter, made of materials with lower densities than the negative electrode terminals (such as titanium and magnesium), helps reduce the weight of the individual battery cells.

[0036] In a second aspect, a connecting member for a battery cell is provided. The battery cell includes an electrode assembly and a first electrode terminal. The electrode assembly includes a first tab. The connecting member includes a first adapter and a second adapter. The first adapter and the second adapter are made of different materials. The first adapter and the second adapter are connected and bonded at the connection point. The first adapter is connected to the first tab. The first electrode terminal is connected to the second adapter, and the first tab and the first electrode terminal have the same polarity. The material of the first adapter is the same as the material of the first tab, and the material of the second adapter is the same as the material of the first electrode terminal. The density of the first adapter is less than the density of the second adapter.

[0037] Thirdly, a battery device is provided, comprising a battery cell according to any embodiment of the first aspect.

[0038] Fourthly, an electrical device is provided, comprising: a battery cell provided in any embodiment of the first aspect or a battery device provided in the third aspect.

[0039] In some embodiments, the electrical device is a vehicle, a ship, or a spacecraft. Attached Figure Description

[0040] Figure 1 is a schematic diagram of a vehicle according to an embodiment of this application; Figure 2 is a structural schematic diagram of a battery device according to an embodiment of this application; Figure 3 shows a perspective view of a battery cell according to an embodiment of this application; Figure 4 shows an exploded view of a battery cell according to an embodiment of this application; Figure 5 is a top view of a battery cell according to an embodiment of this application; Figure 6 is a cross-sectional view (AA) of a battery cell according to an embodiment of this application; Figure 7 is a possible detailed view of part B of the cross-sectional view (AA) of a battery cell according to an embodiment of this application; Figure 8 shows a schematic diagram of a connecting member according to an embodiment of this application; Figure 9 shows a schematic diagram of a connecting member according to certain embodiments of this application; Figure 10 shows a schematic diagram of a connecting member according to certain embodiments of this application; Figure 11 shows a schematic diagram of a connecting member according to certain embodiments of this application; Figure 12 shows a schematic diagram of a connecting member according to certain embodiments of this application; Figure 13 shows a schematic diagram of a connecting member according to certain embodiments of this application; Figure 14 shows a schematic diagram of a connecting member according to certain embodiments of this application; Figure 15 shows a schematic diagram of a connecting member according to certain embodiments of this application; Figure 16 shows a schematic diagram of a connecting member according to certain embodiments of this application; Figure 17 shows a schematic diagram of a connecting member according to certain embodiments of this application. The accompanying drawings are not drawn to scale. Detailed Implementation

[0041] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0042] 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.

[0043] 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.

[0044] In this application, the reference to "embodiment" means that a specific 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 throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0049] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0050] 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.

[0051] 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.

[0052] In some implementations, the battery cell in this application embodiment can be a metal battery. Specifically, the metal battery may include lithium metal secondary batteries, sodium metal batteries, or magnesium metal batteries, etc. This application embodiment does not limit this.

[0053] 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, prevents short circuits while allowing active ions to pass through.

[0054] 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.

[0055] 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.

[0056] As an example, the positive 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, carbon, nickel, magnesium, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, 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.).

[0057] 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 positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate 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 manganese iron phosphate, and lithium manganese iron phosphate and carbon composites.

[0058] In some embodiments, the negative electrode may be a negative electrode sheet, which may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0059] 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.

[0060] 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 electrodes, or carbon, nickel, magnesium, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, or foamed carbon, etc. Composite current collectors can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0061] 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.

[0062] In some embodiments, the electrode assembly further includes a spacer disposed between the positive electrode and the negative electrode.

[0063] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0064] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride, and ceramic.

[0065] 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.

[0066] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0067] 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.

[0068] In some embodiments, a battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing includes a casing and end caps.

[0069] The battery mentioned in the embodiments of this application may be a single physical module comprising one or more battery cells to provide higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, parallel, or mixed via a busbar.

[0070] 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. The battery pack may also be called a battery, battery device, etc., and this application does not limit the terminology thereto.

[0071] 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.

[0072] In some embodiments, the battery may be located in an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0073] The application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also widely used 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 the application fields of power batteries, the market demand is also constantly increasing, and the requirements for the performance of power batteries are also rising, such as the need for lighter weight.

[0074] This application provides a battery cell, a connecting member, and an electrical device. The battery cell includes a housing with a receiving cavity; a first electrode terminal disposed on the housing; an electrode assembly disposed on the receiving cavity, the electrode assembly including a main body and a first tab connected to the main body; the battery cell also includes a connecting member electrically connecting the first electrode terminal and the first tab, the connecting member including a first adapter and a second adapter, the first adapter and the second adapter being made of different materials, the first adapter being connected to the second adapter, the first adapter being connected to the first tab; the first electrode terminal being connected to the second adapter, the first tab and the first electrode terminal having the same polarity; wherein, the material of the first adapter is the same as the material of the first tab, the material of the second adapter is the same as the material of the first electrode terminal, and the density of the first adapter is less than the density of the second adapter.

[0075] In this embodiment, the density of the first adapter component used to connect the first tab is less than that of the second adapter component used to connect the first electrode terminal. The material of the first adapter component is the same as that of the first tab, and the material of the second adapter component is the same as that of the first electrode terminal. The first tab uses a lighter material than the first electrode terminal, which reduces the overall weight of the battery and is beneficial to the performance improvement of the battery cell. At the same time, the dissimilar material composite interface is located at the connecting component, which reduces the connection complexity of the dissimilar material tab and electrode terminal.

[0076] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery devices.

[0077] Electrical equipment can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, 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, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical equipment.

[0078] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0079] For example, as shown in Figure 1, which is a structural schematic diagram of a vehicle 1 according to an embodiment of this application, vehicle 1 can be a gasoline vehicle, a natural gas vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A motor 40, a controller 30, and a battery device 10 can be installed inside vehicle 1. The controller 30 is used to control the battery device 10 to supply power to the motor 40. For example, the battery device 10 can be installed at the bottom, front, or rear of vehicle 1. The battery device 10 can be used to power vehicle 1. For example, the battery device 10 can serve as the operating power source for vehicle 1, for example, for the electrical system of vehicle 1, such as for the power requirements of vehicle 1's starting, navigation, and operation. In another embodiment of this application, the battery device 10 can not only serve as the operating power source for vehicle 1, but also as the driving power source for vehicle 1, replacing or partially replacing gasoline or natural gas to provide driving power for vehicle 1.

[0080] For example, Figure 2 shows a partial structural schematic diagram of the battery device 10 according to an embodiment of this application. As shown in Figure 2, the battery device 10 according to this application embodiment may include multiple battery cells 20 to meet different power usage requirements. The shape of the battery cell 20 according to this application embodiment can be set according to actual application. For example, the battery cell 20 can be a rectangle as shown in Figure 2, or it can be a cylinder or other shape different from that shown in Figure 2. This application embodiment is not limited to this.

[0081] It should be understood that, as shown in FIG. 2, the battery device 10 of this embodiment may further include a housing 11, which can be used to accommodate multiple battery cells 20. The housing 11 of this embodiment has a hollow internal structure, and the multiple battery cells 20 are accommodated within the housing 11. The housing 11 may include two parts, referred to herein as a first housing portion 111 and a second housing portion 112, which are fastened together. The shapes of the first housing portion 111 and the second housing portion 112 can be determined according to the shape of the components housed inside, for example, according to the shape of the combination of the multiple battery cells 20 housed inside. At least one of the first housing portion 111 and the second housing portion 112 has an opening. For example, as shown in Figure 2, the first housing portion 111 and the second housing portion 112 can both be hollow cuboids with one open side each. The openings of the first housing portion 111 and the second housing portion 112 are opposite to each other, and the first housing portion 111 and the second housing portion 112 are interlocked to form a housing 11 with a closed cavity, which can be used to accommodate multiple battery cells 20. The multiple battery cells 20 are connected in parallel, series, or mixed and placed inside the housing 11 formed by the interlocking of the first housing portion 111 and the second housing portion 112.

[0082] For example, unlike what is shown in Figure 2, only one of the first housing portion 111 and the second housing portion 112 may be a hollow cuboid with an opening, while the other is plate-shaped to cover the opening. Taking the second housing portion 112 as a hollow cuboid with one opening, and the first housing portion 111 as a plate-shaped example, then the first housing portion 111 covers the opening of the second housing portion 112 to form a housing 11 with a closed chamber, which can be used to accommodate multiple battery cells 20.

[0083] The overall structure of the battery cell provided in the embodiments of this application is described below with reference to Figures 3 and 4.

[0084] Figure 3 shows a perspective view of a battery cell provided in an embodiment of this application. Figure 4 shows an exploded view of a battery cell provided in an embodiment of this application.

[0085] As shown in Figures 3 and 4, a battery cell according to some embodiments of this application is provided. The battery cell may include a housing 21 and an electrode assembly 22. The housing 21 may include a casing 211 and an end cap 212. Specifically, the casing 211 may be a hollow structure with an opening, and the end cap 212 may cover the opening of the casing 211 to form a receiving cavity, allowing the electrode assembly 22 to be accommodated within the receiving cavity of the casing 21. The bottom wall of the casing 211 may be integrally formed with the other walls of the casing 211, or the bottom wall of the casing 211 may be formed independently of the other walls and then welded to them. This application does not limit the specific embodiment in this regard.

[0086] Corresponding to different shapes of battery cells 20, the casing 211 of the battery cell 20 can be of various shapes, such as a cylinder or a polygonal prism. For example, as shown in Figures 3 and 4, this embodiment mainly describes the casing 211 as a hollow cuboid structure. Alternatively, this embodiment mainly describes the casing 211 as a hollow structure with an opening at one end. However, the relevant descriptions of this embodiment are also applicable to battery cells 20 of other shapes; for simplicity, they will not be elaborated upon here.

[0087] In some embodiments, as shown in FIG4, the housing 21 is provided with at least two electrode terminals 214, each including at least one first electrode terminal 214a and at least one second electrode terminal 214b, wherein the first electrode terminal 214a and the second electrode terminal 214b have opposite polarities. For example, the first electrode terminal 214a can be a positive electrode terminal, and the second electrode terminal 214b can be a negative electrode terminal; or, the first electrode terminal 214a can be a negative electrode terminal, and the second electrode terminal 214b can be a positive electrode terminal. The electrode assembly 22 may include a main body 222 and at least two tabs 221, each including at least one first tab 221a and at least one second tab 221b, wherein the first tab 221a and the second tab 221b have opposite polarities. For example, the first electrode tab 221a is the positive electrode tab, and 221b is the negative electrode tab; or, the first electrode tab 221a is the negative electrode tab, and the second electrode tab 221b is the positive electrode tab. The positive electrode terminal is used for electrical connection to the positive electrode tab of the electrode assembly 22, and the negative electrode terminal is used for electrical connection to the negative electrode tab of the electrode assembly 22. For example, the positive electrode terminal can be electrically connected to the positive electrode tab via a connecting member 23, and the negative electrode terminal can be electrically connected to the negative electrode tab via a connecting member 23.

[0088] It should be understood that each electrode terminal 214 in the embodiments of this application can be disposed on any wall, and multiple electrode terminals 214 can be disposed on the same wall or different walls of the battery cell 20. For example, as shown in FIG3, each battery cell 20 includes two electrode terminals 214, and the two electrode terminals 214 are located on the same wall. For example, both electrode terminals 214 can be located on the end cap 212.

[0089] For example, taking the case where each battery cell 20 includes two electrode terminals 214 and the two electrode terminals 214 are located on the same wall, unlike the case shown in Figure 3, the two electrode terminals 214 can also be located in the housing 211.

[0090] An electrolyte injection hole 215 can also be provided on the outer casing 21, through which electrolyte can be injected into the battery cell 20 and then sealed by a sealing component.

[0091] The battery cell 20 can also be provided with a bottom support plate 24, which can support the electrode assembly 22 to avoid collision and compression between the electrode assembly 22 and the bottom wall of the housing 211.

[0092] An insulating layer 25 may also be provided on the outside of the electrode assembly 22 to isolate static electricity between the electrode assembly 22 and the outer shell.

[0093] The positive electrode tab can be formed by stacking the portion of the positive electrode sheet that is not coated with the positive active material, and the negative electrode tab can be formed by stacking the portion of the negative electrode sheet that is not coated with the negative active material.

[0094] The positive electrode sheet of this application embodiment can be provided with a positive electrode active material that can reversibly extract and insert metal ions. This positive electrode active material can be flexibly configured according to actual applications. For example, the positive electrode active material may include a nickel-containing compound, which can effectively increase the energy density and cycle life of the battery cell 20, and also increase the amount of gas generated during the use of the battery cell 20.

[0095] The battery cell 20 may be provided with a pressure relief mechanism 213. The pressure relief mechanism 213 can release the internal pressure of the battery cell 20. For example, it is actuated to release the internal pressure or temperature when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold. When the internal pressure or temperature of the battery cell 20 reaches the predetermined threshold, the pressure relief mechanism 213 actuates or a weak structure provided in the pressure relief mechanism 213 is destroyed, thereby forming an opening or channel for the release of internal pressure or temperature. This threshold design varies depending on design requirements. The threshold may depend on the materials of one or more of the positive electrode, negative electrode, electrolyte, and separator in the battery cell 20.

[0096] The term "actuation" as used in this application refers to the pressure relief mechanism 213 being activated or undergoing a certain state, thereby releasing the internal pressure and temperature of the battery cell 20. The actions of the pressure relief mechanism 213 may include, but are not limited to: movement of components within the pressure relief mechanism 213 to form an exhaust channel, rupture, breakage, tearing, or opening of at least a portion of the pressure relief mechanism 213, etc. When the pressure relief mechanism 213 is actuated, the high-temperature, high-pressure substances inside the battery cell 20 are discharged outwards from the actuated portion as exhaust materials. This method enables pressure and temperature relief of the battery cell under controllable pressure or temperature, thereby preventing potentially more serious accidents.

[0097] The emissions from the battery cell 20 mentioned in this application include, but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of separators, high-temperature and high-pressure gases generated by the reaction, flames, etc.

[0098] The following description, with reference to Figures 5-7, illustrates a battery cell provided in an embodiment of this application.

[0099] Figure 5 is a top view of a battery cell according to an embodiment of this application. Figure 6 is a cross-sectional view (AA) of a battery cell according to an embodiment of this application. Figure 7 is a possible detailed view of part B of the cross-sectional view (AA) of a battery cell according to an embodiment of this application.

[0100] Please refer to Figures 5, 6, and 7 together. The battery cell 20 may include a housing 21 with a receiving cavity. The first electrode terminal 214a of the battery cell 20 is disposed on the housing 21. The battery cell 20 also includes an electrode assembly 22 disposed on the receiving cavity. The electrode assembly 22 includes a main body 222 and a first tab 221a. The first tab 221a can be a positive or negative tab, which is not limited in this embodiment. The battery cell 20 may also include a connecting member 23, which includes a first adapter 231 and a second adapter 232. The first adapter 231 and the second adapter 232 are combined to realize the electrical connection between the tab 221 of the electrode assembly 22 and the electrode terminal 214. The first adapter 231 and the second adapter 232 are made of different materials and are connected together. The first adapter 231 is connected to the first tab 221a. The battery cell 20 includes a first electrode terminal 214a, which can be either a positive or negative electrode terminal; this embodiment does not limit this. The first electrode terminal 214a is connected to a second adapter component 232. The first tab 221a has the same polarity as the first electrode terminal 214a; that is, the adapter component 232 connects electrode terminals and tabs of the same polarity.

[0101] The material of the first adapter component 231 is the same as that of the first tab 221a, the material of the second adapter component 232 is the same as that of the first electrode terminal 214a, and the density of the first adapter component 231 is less than that of the second adapter component 232.

[0102] In this embodiment of the application, the electrical connection between components can be achieved by means of welding, contact connection, or other methods, so that current can be allowed to pass between the components.

[0103] The first adapter 231 is electrically connected to the first tab 221a, and the second adapter 232 is connected to the first electrode terminal 214a. This can be understood as the first adapter 231 being directly connected to the first tab 221a and allowing current to flow, and the second adapter 232 being directly connected to the first electrode terminal 214a and allowing current to flow.

[0104] The embodiments of this application do not limit the shape of the first adapter 231 and the second adapter 232. For convenience, the accompanying drawings of this application use the relatively regular shape of the first adapter 231 and the second adapter 232 as an example, but this should not constitute a limitation on the shape of the first adapter 231 and the second adapter 232 of this application.

[0105] For example, the first adapter component 231 and the first electrode tab 221a can be connected by welding. For instance, if the connection surfaces of the first adapter component 231 and the first electrode tab 221a are flat, they can be welded together by ultrasonic welding.

[0106] For example, the second adapter 232 and the first electrode terminal 214a can be connected by welding. For instance, the second adapter 232 and the first electrode terminal 214a can be welded together by laser penetration welding.

[0107] The first electrode tab 221a and the first electrode terminal 214a have the same polarity. For example, the first electrode tab 221a can be a positive electrode tab and the first electrode terminal 214a can be a positive electrode terminal; or the first electrode tab 221a can be a negative electrode tab and the first electrode terminal 214a can be a negative electrode terminal.

[0108] The material of the first adapter component 231 and the first electrode 221a can be the same. This can mean that the first adapter component 231 and the first electrode 221a are made of completely identical materials, or that their main material costs are the same, and any impurities doped into them do not affect the main properties of the materials. The main purpose of using the same material for the first adapter component 231 and the first electrode 221a is to prevent connection difficulties caused by connecting dissimilar materials. In other words, if the use of the two materials does not affect their connection, they can be considered to be the same material in this embodiment. For example, the material of the first adapter component 231 can be titanium or titanium doped with trace amounts of carbon or other elements, and the material of the first electrode 221a can also be titanium or titanium doped with trace amounts of carbon or other elements. When they are welded, it can be considered as welding between the same materials.

[0109] The density of the first adapter component 231 being less than the density of the second adapter component 232 can mean that the density of the material of the first adapter component 231 is less than the density of the material of the second adapter component 232. For example, the material of the first adapter component 231 is magnesium (density 1.74 g / cm3), and the material of the second adapter component 232 is nickel (density 8.85 g / cm3). Another example is that the material of the first adapter component 231 is titanium (density 4.47 g / cm3), and the material of the second adapter component 232 is copper (density 8.90 g / cm3). These examples are merely illustrative, and the embodiments of this application are not limited thereto. For example, the material of the second adapter component 232 can also be manganese, chromium, etc.

[0110] In this embodiment, the density of the first adapter component 231 used to connect the first tab 221a is less than that of the second adapter component 232 used to connect the first electrode terminal 214a. The material of the first adapter component 231 is the same as that of the first tab 221a, and the material of the second adapter component 232 is the same as that of the first electrode terminal 214a. The first tab 221a uses a lighter material than the first electrode terminal 214a, which reduces the overall weight of the battery and is beneficial to the performance improvement of the battery cell. At the same time, the heterogeneous material composite interface is located at the connecting component 23, which reduces the connection complexity of the heterogeneous material tab and electrode terminal.

[0111] Figure 8 shows a schematic diagram of a connecting member provided in one embodiment of this application.

[0112] As shown in Figure 8, the first adapter 231 and the second adapter 232 of the connecting member 23 can be stacked along the thickness direction of the second adapter 232.

[0113] The second adapter 232 and the first adapter 231 can be connected at the entire surface of the second adapter 232 facing the first adapter 231, or at a portion of the surface of the second adapter 232 facing the first adapter 231.

[0114] In this embodiment, the surface area of ​​the second adapter 232 facing the first adapter 231 is larger. The first adapter 231 of the connecting member 23 is connected to the surface of the second adapter 232 facing the first adapter 231, which can increase the contact area between the first adapter 231 and the second adapter 232, improve the flow efficiency, and reduce the heat loss at the connecting member 23.

[0115] In some possible embodiments, the first adapter 231 and the second adapter 232 are connected in a solid-solid composite manner.

[0116] The first adapter 231 and the second adapter 232 can be solid-solid composited by heating and pressurizing them to fuse at the contact interface. For example, the hardness of the first adapter 231 and / or the second adapter 232 can be reduced by heating with an induced current, making it easier to composite at the contact interface. The first adapter 231 and the second adapter 232 can also be connected in other ways, such as by explosive bonding or by forming an alloy. The above composite methods are merely exemplary and are not limited to this embodiment.

[0117] The composite surface of the first adapter component 231 and the second adapter component 232 can be planar. When the composite surface of the first adapter component 231 and the second adapter component 232 is planar, the composite difficulty of the first adapter component 231 and the second adapter component 232 is low, and the composite process is simple. The composite surface of the first adapter component 231 and the second adapter component 232 can also be curved or irregular, such as a sawtooth surface. When the composite surface of the first adapter component 231 and the second adapter component 232 is curved or irregular, the composite contact area of ​​the first adapter component 231 and the second adapter component 232 is larger, the composite is more firm, and it is less likely to loosen or fall off, thereby maintaining a low contact resistance and reducing heat loss.

[0118] A composite interface 233 can be formed between the first adapter 231 and the second adapter 232. The composite interface 233 can be a composite region in an alloy state. Alternatively, the composite interface 233 can be a region where the first adapter 231 and the second adapter 232 are not alloyed, but their materials do not have a clear interface. The composite interface 233 can also be an interface region formed by the two components bonding after heating and softening; this application does not limit this.

[0119] In some possible embodiments, the second adapter 232 includes an electrode terminal connection area 2321 and a tab connection area 2322. The electrode terminal connection area 2321 of the second adapter 232 is connected to the first electrode terminal 214a, and the tab connection area 2322 of the second adapter 232 is connected to the first adapter 231.

[0120] For example, the tab connection area 2322 and the first adapter component 231 can be stacked along the thickness direction of the tab connection area 2322.

[0121] Figure 8 only shows an example where the first adapter 231 is located on the side of the tab connection area 2322 facing the main body 222 of the electrode assembly 22. In the case where the first tab 221a passes around the connecting member 23 from both sides and is connected to the first adapter 231 on the side of the connecting member 23 away from the main body 222 of the electrode assembly 22, the first adapter 231 may also be located on the side of the tab connection area 2322 away from the main body 222 of the electrode assembly 22. This embodiment is not limited to this.

[0122] In some possible embodiments, the first adapter 231 is disposed on the side of the tab connection area 2322 facing the main body 222 of the electrode assembly 22. The right side of FIG8 may be the electrode terminal connection area 2321 where the second adapter 232 connects to the first electrode terminal 214a, and the lower half of the left side, i.e., the substrate portion, may be the tab connection area 2322 of the second adapter 232. The tab connection area 2322 of the second adapter 232 does not necessarily mean that the second adapter 232 needs to be connected to the tab. In FIG8, the main function of the tab connection area 2322 of the second adapter 232 is to provide a surface for connection with the first adapter 231. When the first adapter 231 is connected to the first tab 221a, current can be transmitted through the connection surface between the first adapter 231 and the second adapter 232 to the second adapter 232, and then to the first electrode terminal 214a.

[0123] In this embodiment, the first adapter 231 is connected to the second adapter 232 at the surface of the tab connection area of ​​the second adapter 232 facing the main body 222. Compared with connecting to the entire surface of the second adapter 232, the connection area between the first adapter 231 and the second adapter 232 is reduced, the connection difficulty is reduced, and the process cost is reduced.

[0124] On the other hand, the first adapter 231 connects to the second adapter 232 at the electrode terminal connection area 2322 facing the surface of the second adapter 232, reducing the thickness of the second adapter 232 in the electrode terminal connection area 2321 and lowering material costs. The reduced thickness of the second adapter 232 in the electrode terminal connection area 2321 also reduces the difficulty of connecting the second adapter 232 to the first electrode terminal 214a. For example, when connecting the second adapter 232 and the first electrode terminal 214a by laser penetration welding, the reduced thickness of the electrode terminal connection area 2321 can reduce the laser power and the difficulty of penetration.

[0125] In some possible embodiments, as shown in FIG9, a portion of the first adapter 231 is stacked with the tab connection area 2322, and another portion is stacked with the electrode terminal connection area 2321.

[0126] Figure 9 illustrates an example of a second adapter 232 including a base plate 2328 and a protrusion 2329 disposed on the base plate. A first adapter 231 is disposed on both sides of the protrusion 2329 and is stacked with the second adapter 232 along the thickness direction. However, the embodiments of this application are not limited to this.

[0127] In this embodiment, the electrode terminal connection area 2321 and the tab connection area 2322 of the first adapter component 231 and the second adapter component 232 are connected, maximizing the current flow area and improving the current flow efficiency.

[0128] In Figure 9, the right side of the base plate can be the electrode terminal connection area 2321 of the second adapter component 232, and the left side of the base plate can be the tab connection area 2322 of the second adapter component 232.

[0129] In some possible embodiments, the second adapter 232 may further include a transition region 2323 that connects the tab connection region 2322 and the electrode terminal connection region 2321, wherein the tab connection region 2322 is further away from the main body 222 than the electrode terminal connection region 2321.

[0130] Figures 8 and 9 schematically show that the connecting member 23 is connected to the electrode terminal connection area 2321 via a transition area 2323. The transition area 2323 can be set according to actual needs. The connecting member 23 may also omit the transition area 2323. For example, when the height difference between the electrode terminal and the electrode is small, the part of the electrode terminal connection area 2322 and the part of the electrode terminal connection area 2321 can be at the same horizontal level, thus the transition area 2323 can be omitted.

[0131] The accompanying drawings of this application provide an example of the tab connection area 2322 and the electrode terminal connection area 2321 being connected by a transition area 2323, but the embodiments of this application are not limited thereto.

[0132] In some possible embodiments, a blind hole 2325 is provided on the surface of the second adapter 232 that is away from the main body 222.

[0133] Some embodiments of this application show a blind hole 2325 disposed on the surface of the second adapter 232 away from the main body 222, while some embodiments do not show it. The blind hole 2325 can be disposed as needed, and this application will not elaborate on it further.

[0134] In this embodiment, the blind hole 2325 can effectively reduce the thickness of the second adapter component 232 on the bottom wall of the blind hole 2325, and when connected by means such as through welding, the power of the laser and the difficulty of penetration can be reduced.

[0135] Figure 10 shows a schematic diagram of a connecting member provided in some embodiments of this application.

[0136] In some possible embodiments, as shown in FIG10, the first adapter 231 is connected to the end face of the second adapter 232 along a first direction, wherein the first direction is perpendicular to the thickness direction of the second adapter 232.

[0137] As shown in Figure 10, the second adapter component 232 of the connecting member 23 has four end faces facing perpendicular to the thickness direction. For example, the first adapter component 231 can be connected to the end face between the first electrode terminal 214a and the first tab 221a. The first adapter component 231 can also be connected to other end faces, and this embodiment is not limited thereto.

[0138] For example, as shown in FIG11, the first adapter 231 can also be connected to the two end faces of the second adapter 232.

[0139] In this embodiment, the first adapter 231 and the second adapter 232 are combined at the end face. When processing the adapter 23, the profile of the large first adapter 231 and the profile of the large second adapter 232 can be combined and then physically or by laser cutting to form the connecting component as shown in Figure 9. The processing technology is simple and saves processing costs.

[0140] Figures 11-17 provide examples of the first adapter 231 comprising two sub-components.

[0141] The first adapter 231 may include a first sub-component 231a and a second sub-component 231b that are spaced apart.

[0142] As a possible example, Figure 11 shows a schematic diagram of a connecting member provided in some embodiments of this application.

[0143] In some possible embodiments, as shown in FIG11, the first adapter component 231 of the connecting member 23 includes a first sub-component 231a and a second sub-component 231b spaced apart. Exemplarily, the first sub-component 231a and the second sub-component 231b may be partially connected to the electrode terminal connection area 2321 of the second adapter component 232 and partially connected to the tab connection area 2322 of the second adapter component 232, but this application is not limited thereto.

[0144] The first sub-component 231a and the second sub-component 231b of the first adapter 231 can extend along a second direction, wherein the second direction is perpendicular to the thickness direction of the second adapter 232.

[0145] The spacing between the first sub-component 231a and the second sub-component 231b can be understood as the existence of a gap between the first sub-component 231a and the second sub-component 231b.

[0146] The second direction can be the same as or different from the first direction. For example, in Figure 10, the first direction is the same as the second direction, while in Figure 11, the second direction is perpendicular to the first direction.

[0147] In some possible embodiments, the tab connection area 2322 of the second adapter 232 extends along a second direction, and the first sub-component 231a and the second sub-component 231b are disposed on both sides of the second adapter 232. The first sub-component 231a and the second sub-component 231b are connected to the second adapter 232 on both sidewalls of the second adapter 232.

[0148] Since the tabs of the electrode assembly 22 can be configured as two sub-parts (e.g., the first tab 221a in Figure 4), the area of ​​the first adapter 231 located between the two sub-parts of the tab can be left unconnected to the tab, thereby saving material in the middle part and reducing the material cost of the first adapter 231.

[0149] As one possible embodiment, FIG12 shows a schematic diagram of a connecting member provided in some embodiments of the present application.

[0150] As shown in Figure 12, the connecting member 23 has a second adapter component 232 including an electrode terminal connection area 2321 and an electrode tab connection area 2322. The electrode tab connection area 2322 includes a base plate 2328 and a protrusion structure 2329 disposed on the base plate. A first sub-component 231a and a second sub-component 231b are spaced apart and extend along a second direction. The first sub-components 231a and 231b are stacked on top of the base plate 2328. The protrusion structure 2329 is located between the first sub-components 231a and 231b.

[0151] The first sub-component 231a and the second sub-component 231b can be connected to the second adapter 232 at the base plate 2328 or at the side wall of the protruding structure 2329.

[0152] Optionally, the first sub-component 231a and the second sub-component 231b are combined with the second adapter 232 at at least a portion of the surface of the tab connection area 2322 facing the main body 222. The first sub-component 231a and the second sub-component 231b may also be combined with the second adapter 232 at the sidewalls on both sides of the protruding structure 2329.

[0153] In this embodiment, the electrode terminal connection area 2321 is not connected to the tab. Therefore, the second connection component 232 can only provide a base plate 2328 extending in the second direction and a protruding structure 2329 in the tab connection area 2322 to provide the first sub-component 231a and the second sub-component 231b, thereby reducing the difficulty of composite assembly.

[0154] Referring also to Figures 13 and 14, Figure 13 shows a schematic diagram of a connecting member provided in some embodiments of the present application, and Figure 14 shows a schematic diagram of a connecting member provided in some embodiments of the present application.

[0155] As shown in Figure 13, the connecting member 23 has four end faces of the second adapter component 232 facing the first direction. A portion of the first end face of the second adapter component facing the first electrode tab 221a extends towards the first electrode tab 221a to form an extension. The first adapter component 231 includes a first sub-component 231a and a second sub-component 231b spaced apart. The first sub-component 231a and the second sub-component 231b extend from the first end face towards the first electrode tab 221a and are disposed on both sides of the extension. The first sub-component 231a and the second sub-component 231b can be connected to the second adapter component 232 at least a portion of the first end face, or they can be connected to the second adapter component 232 on both sides of the extension.

[0156] In this embodiment, the first sub-component 231a and the second sub-component 231b can pass through the side of the extension and the first end face of the second adapter, which improves the flow efficiency compared to not having an extension.

[0157] On the other hand, the first adapter component 231 is a single piece in the thickness direction, which does not require additional thinning process and reduces process cost.

[0158] As shown in Figure 14, the connecting member 23 differs from the connecting member 23 in Figure 13 in that the dimension of the electrode terminal connection area of ​​the second connecting member 232 along the first direction can be smaller than the dimension of the connecting member 23 along the first direction.

[0159] Since the dimension of the connecting member 23 along the first direction may be slightly larger than the dimension of the connection portion between the first electrode terminal and the second adapter 232 along the first direction, reducing the dimension of the electrode terminal connection area of ​​the second connecting member 232 along the first direction helps to reduce the material used in the second connecting member 232 and reduce material costs.

[0160] The space between the first sub-component 231a and the second sub-component 231b may also be without a component.

[0161] As one possible embodiment, FIG15 shows a schematic diagram of a connecting member provided in some embodiments of this application.

[0162] As shown in Figure 15, the connecting member 23 has four second adapter components 232 facing the first direction. A first adapter component 231 is disposed on the first end face of the second adapter component facing the first electrode tab 221a. The first adapter component 231 includes a first sub-component 231a and a second sub-component 231b spaced apart. The first sub-component 231a and the second sub-component 231b extend from the first end face towards the first electrode tab 221a. The first sub-component 231a and the second sub-component 231b can be combined with the second adapter component 232 at least partially on the first end face.

[0163] In this embodiment, the first adapter component 231 is provided with the first sub-component 231a and the second sub-component 231b in the tab connection area, leaving the middle area empty, thereby saving material usage and reducing the material cost of the connecting component 23.

[0164] The second adapter 232 can also support the first sub-component 231a and the second sub-component 231b via the base plate.

[0165] Optionally, the conductivity of the material of the second adapter 232 is greater than that of the first adapter 231.

[0166] Since the conductivity of the material of the second adapter 232 is greater than that of the first adapter 231, setting the first sub-component 231a and the second sub-component 231b only in the tab connection area can reduce the area of ​​the material of the first adapter 231 through which the current flows, thereby reducing energy loss.

[0167] Referring also to Figures 16 and 17, Figure 16 shows a schematic diagram of a connecting member provided in some embodiments of the present application, and Figure 17 shows a schematic diagram of a connecting member provided in some embodiments of the present application.

[0168] As shown in Figure 16, the connecting member 23 has a second connecting component 232 including a tab connection area and an electrode terminal connection area. The second adapter component includes a first base plate and a second base plate spaced apart along a first direction in the tab connection area. The first base plate and the second base plate are connected to or integrally formed with the first end face of the second adapter component. A first sub-component 231a is disposed on the first base plate, and a second sub-component 231b is disposed on the second base plate.

[0169] In this embodiment, the first sub-component 231a is disposed on the first base plate, and the second sub-component 231b is disposed on the second base plate. The first sub-component 231a and the second sub-component 231b can pass through the first end face of the second adapter or the first base plate and the second base plate, which improves the flow efficiency compared to passing through only the first end face.

[0170] Optionally, the first sub-component 231a and the second sub-component 231b can be combined with the first base plate and the second base plate, or they can be combined with the first end face.

[0171] As shown in Figure 17, the connecting member 23 differs from the connecting member 23 in Figure 16 in that the dimension of the electrode terminal connection area of ​​the second connecting component 232 along the first direction can be smaller than the dimension of the connecting member 23 along the first direction.

[0172] Since the dimension of the connecting member 23 along the first direction may be slightly larger than the dimension of the connection portion between the first electrode terminal and the second adapter 232 along the first direction, reducing the dimension of the electrode terminal connection area of ​​the second connecting member 232 along the first direction helps to reduce the material used in the second connecting member 232 and reduce material costs.

[0173] In some embodiments of this application, the density of the first adapter 231 may be less than 5 g / cm3. For example, the material of the first adapter 231 may be titanium, titanium doped with certain elements, magnesium, etc.

[0174] In this embodiment, the density of the first adapter component 231 is less than 5 g / cm3, and the mass of the electrode assembly 22 can be lighter, which is beneficial to reducing the weight of the battery cell 20.

[0175] Furthermore, the density of the first adapter component 231 can be less than 4.8 g / cm3 and greater than 3 g / cm3. When the density of the first adapter component 231 is within this range, the doping of light metals can be reduced, thereby reducing the reactivity of the electrode and increasing the stability of the electrode.

[0176] In this embodiment, the first tab 221a connected to the connecting member 23 can be a negative electrode tab, and the first electrode terminal 214a can be a negative electrode terminal. Since metal ions (e.g., lithium ions) in the electrolyte migrate towards the negative electrode, to prevent corrosion or alloy formation, the negative electrode is generally made of an inert metal that is unlikely to form an alloy with the metal ions in the electrolyte. The commonly used negative electrode current collector is copper foil, which has a high density, resulting in a high overall battery weight and making it difficult to carry and transport. Therefore, using negative electrode tabs and the first adapter 231 with densities lower than those of the negative electrode terminals, such as titanium and magnesium, is beneficial for reducing the weight of the battery cell.

[0177] In some possible embodiments, the first adapter 231 is made of titanium.

[0178] When selecting positive and / or negative electrode materials for battery cells, many factors need to be considered. Many light metals, such as sodium, magnesium, aluminum, and zinc, react with water in aqueous electrolytes, causing electrode corrosion and releasing hydrogen gas, which is detrimental to battery stability. In such cases, alternative electrolyte types or electrode modification may be necessary. Some light metals, such as aluminum and titanium, have low redox potentials (-1.663V and -1.63eV, respectively), readily forming a dense oxide film on their surface. Electron migration through this oxide film passivates the reaction between the metal within the oxide film and the solution. Therefore, in most cases, the electromotive force of these metals as electrodes is higher than their redox potential in their pure metallic state, making them suitable as electrodes. However, aluminum in electrolytes, due to its microstructure, may form alloys with metal ions in the solution. For example, aluminum's octet structure is similar to lithium, easily forming lithium-aluminum alloys, which may reduce the cycle capacity of the battery cell. This problem is more pronounced when aluminum is used as the negative electrode current collector. When titanium is used as the negative electrode current collector in a battery cell, there is no need to consider the issue of alloying with metals in the electrolyte. In summary, using titanium as the material for the first adapter component is beneficial for the stability of the battery cell electrodes, the stability of the electrolyte, and for maintaining the cycle capacity and lifespan of the battery cell.

[0179] In some possible embodiments, the second adapter 232 is made of copper.

[0180] Copper possesses excellent electrical conductivity, corrosion resistance, and processability, meeting the requirements for battery electrode materials. Furthermore, copper can improve battery cycle life and capacity, while reducing internal resistance and voltage drop.

[0181] When the material of the first adapter 231 is magnesium, magnesium may react easily with aqueous electrolyte. Optionally, other types of electrolytes, such as solid electrolytes or organic solvent electrolytes, can be used to stabilize the magnesium electrode. Magnesium can also be stabilized by modifying it, such as coating the surface of magnesium with silver. This application does not limit this.

[0182] Optionally, the connecting member 23 can also connect the positive electrode tab to the positive electrode terminal.

[0183] The material of the connecting member 23 can also be other combinations, for example, the material of the first adapter 231 can be aluminum, and the material of the second adapter 232 can be copper. This application does not limit this.

[0184] According to certain embodiments of this application, the battery cell 20 includes at least two electrode terminals, an electrode assembly 22, and a connecting member 23. The electrode assembly 22 includes at least two tabs. The connecting member 23 includes a titanium adapter and a copper adapter, which are combined to connect the negative electrode tab of the electrode assembly 22 to the negative electrode terminal. The negative electrode tab is a titanium tab, and the titanium adapter and the titanium tab are electrically connected by ultrasonic welding. The negative electrode terminal is a copper electrode terminal, and the copper adapter and the copper electrode terminal are electrically connected by laser penetration welding. The titanium adapter and the copper adapter are electrically connected and composite at the connection point. The titanium adapter and the titanium negative electrode foil effectively reduce the weight of the battery cell. The connecting member 23, formed by the titanium-copper adapter, enables the electrical connection between the titanium foil of the negative electrode and the copper electrode terminal, reducing the processing difficulties associated with connecting dissimilar materials like titanium and copper.

[0185] According to some embodiments of this application, this application also provides a battery device including a battery cell described in any of the above embodiments.

[0186] According to some embodiments of this application, this application also provides an electrical device, including the battery device described in any of the above embodiments, and the battery device is used to provide electrical energy to the electrical device.

[0187] The electrical device can be any of the aforementioned devices or systems that utilize battery devices.

[0188] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The outer casing (21) has a receiving cavity; A first electrode terminal (214a) is disposed on the housing (21); An electrode assembly (22) is disposed in the receiving cavity. The electrode assembly (22) includes a main body (222) and a first electrode tab (221a), which is connected to the main body (222). A connecting member (23) electrically connects the first electrode terminal (214a) and the first electrode tab (221a). The connecting member (23) includes a first adapter (231) and a second adapter (232). The first adapter (231) and the second adapter (232) are made of different materials. The first adapter (231) is connected to the second adapter (232). The first adapter (231) is connected to the first electrode tab (221a). The first electrode terminal (214a) is connected to the second adapter (232). The first electrode tab (221a) and the first electrode terminal (214a) have the same polarity. The material of the first adapter (231) is the same as that of the first tab (221a), the material of the second adapter (232) is the same as that of the first electrode terminal (214a), and the density of the first adapter (231) is less than that of the second adapter (232).

2. The battery cell according to claim 1, characterized in that, The first adapter (231) and the second adapter (232) are stacked together along the thickness direction of the second adapter (232).

3. The battery cell according to claim 2, characterized in that, The first adapter (231) and the second adapter (232) are connected by a solid-solid composite method.

4. The battery cell according to claim 2 or 3, characterized in that, The second adapter (232) includes an electrode terminal connection area (2321) and a tab connection area (2322). The electrode terminal connection area (2321) is connected to the first electrode terminal (214a), and the tab connection area (2322) is connected to the first adapter (231).

5. The battery cell according to claim 4, characterized in that, The first adapter (231) is at least partially disposed on the side of the tab connection area (2322) facing the main body (222).

6. The battery cell according to claim 4, characterized in that, A portion of the first adapter component (231) is stacked with the tab connection area (2322), and another portion is stacked with the electrode terminal connection area (2321).

7. The battery cell according to any one of claims 4 to 6, characterized in that, The second adapter (232) further includes a transition region (2323) that connects the tab connection region (2322) and the electrode terminal connection region (2321). The tab connection region (2322) is further away from the main body (222) than the electrode terminal connection region (2321).

8. The battery cell according to claim 1, characterized in that, The first adapter (231) is connected to the end face of the second adapter (232) along a first direction, wherein the first direction is perpendicular to the thickness direction of the second adapter (232).

9. The battery cell according to any one of claims 1 to 8, characterized in that, The first adapter (231) includes a first sub-component (231a) and a second sub-component (231b) that are spaced apart.

10. The battery cell according to claim 9, characterized in that, The first sub-component (231a) and the second sub-component (231b) extend along a second direction, wherein the second direction is perpendicular to the thickness direction of the second adapter (232).

11. The battery cell according to claim 10, characterized in that, The second adapter (232) includes an electrode terminal connection area (2321) and a tab connection area (2322). The tab connection area (2322) includes a base plate (2328) and a protrusion structure (2329) disposed on the base plate (2328). The first sub-component (231a) and the second sub-component (231b) are stacked with the base plate (2328). The protrusion structure (2329) is disposed between the first sub-component (231a) and the second sub-component (231b).

12. The battery cell according to claim 11, characterized in that, The first sub-component (231a) and the second sub-component (231b) are combined with the second adapter (232) at at least a portion of the surface of the tab connection area (2322) facing the main body (222), and / or The first sub-component (231a) and the second sub-component (231b) are combined with the second adapter (232) at the two side walls of the protruding structure (2329).

13. The battery cell according to any one of claims 1 to 12, characterized in that, The density of the first adapter (231) is less than 5 g / cm3.

14. The battery cell according to claim 13, characterized in that, The first adapter (231) is made of titanium, titanium containing impurities, or magnesium.

15. The battery cell according to claim 13, characterized in that, The material of the second adapter (232) is copper, nickel or manganese.

16. The battery cell according to any one of claims 1 to 15, characterized in that, The second adapter (232) has a blind hole on the surface away from the main body (222).

17. The battery cell according to any one of claims 1 to 16, characterized in that, The first electrode terminal (214a) is a negative electrode terminal, and the first tab (221a) is a negative tab.

18. A connecting member for a battery cell, characterized in that, The battery cell includes a housing (21), an electrode assembly (22), and a first electrode terminal (214a). The housing (21) has a receiving cavity, the electrode assembly (22) is disposed in the receiving cavity, and the first electrode terminal (214a) is disposed in the housing (21). The electrode assembly (22) includes a main body (222) and a first tab (221a), and the first tab is connected to the main body (222). The connecting member (23) includes a first adapter (231) and a second adapter (232). The first adapter (231) and the second adapter (232) are made of different materials. The first electrode terminal (214a) is connected to the second adapter (232). The first adapter (231) is connected to the first tab (221a). The first tab (221a) and the first electrode terminal (214a) have the same polarity. The material of the first adapter (231) is the same as that of the first tab (221a), the material of the second adapter (232) is the same as that of the first electrode terminal (214a), and the density of the first adapter (231) is less than that of the second adapter (232).

19. A battery device, characterized in that, It includes multiple battery cells according to any one of claims 1 to 17.

20. An electrical appliance, characterized in that, Includes a battery cell according to any one of claims 1 to 17 or a battery device according to claim 19, wherein the battery cell or the battery device is used to provide electrical energy.

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