Battery cell, battery and electrical apparatus

Abstract

Provided are a battery cell, a battery, and electrical apparatus. The battery cell (200) comprises: a housing (221); and an electrode assembly (21), the electrode assembly (21) being provided with a tab (211); and a current collector plate (30), comprising a first connecting piece (31) and a second connecting piece (32) connected to each other. The first connecting piece (31) is welded to the tab (211), and the second connecting piece (32) is welded to the housing (221). In a direction perpendicular to the thickness direction of the second connecting piece (32), the projection of the first connecting piece (31) at least partially overlaps with the projection of the second connecting piece (32). The current collector plate (30) can improve the stability and reliability of the connection between the housing (221) and the tab (211). In addition, the current collector plate (30) has a small thickness, and can reduce the occupied space in the battery cell (200), so as to improve the energy density of the battery cell (200).

Description

Battery cells, batteries and electrical devices

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on September 25, 2023, with application number 202311242972.7 and invention name “Battery Cell, Battery and Electrical Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the field of battery technology, and more specifically, relates to a battery cell, a battery, and an electrical device. Background Art

[0003] The statements herein provide only background information relevant to this application and do not necessarily constitute prior art. Energy conservation and emission reduction are key to the sustainable development of the automotive industry. Electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of the industry's sustainable development. Battery technology is a crucial factor in the development of electric vehicles.

[0004] Cylindrical batteries require a current collector plate to connect the negative electrode tab to the battery case, allowing the case to serve as the negative electrode terminal. The negative electrode tab is typically made of copper, while the battery case is typically made of steel. To facilitate welding, the current collector plate typically utilizes a laminated composite structure of copper and steel sheets. However, this laminated composite structure occupies a large space and reduces the battery's energy density.

[0005] Application Contents

[0006] The purpose of the embodiments of the present application is to provide a battery cell, a battery, and an electrical device to solve the problem in the related art that the stacked composite current collecting plates occupy a large space and reduce the energy density of the battery.

[0007] In a first aspect, an embodiment of the present application provides a battery cell, comprising:

[0008] case;

[0009] The electrode assembly is installed in the shell and is provided with a tab;

[0010] The current collecting plate includes a first connecting plate and a second connecting plate, wherein the first connecting plate is connected to the second connecting plate, the first connecting plate is welded to the tab, and the second connecting plate is welded to the shell;

[0011] Along a direction perpendicular to the thickness of the second connecting piece, a projection of the first connecting piece and a projection of the second connecting piece at least partially overlap.

[0012] In the technical solution of the embodiment of the present application, a first connecting piece is connected to a second connecting piece to form a current collecting plate, so that the first connecting piece is welded to the pole tab of the battery cell, and the second connecting piece is welded to the shell of the battery cell, so as to realize the connection between the shell and the pole tab of the current collecting plate, thereby improving the stability and reliability of the connection; in the thickness perpendicular to the second connecting piece, the projection of the first connecting piece and the projection of the second connecting piece are at least partially overlapped, so that in the thickness of the manufactured current collecting plate, the first connecting piece and the second connecting piece are at least partially overlapped, which can reduce the thickness of the current collecting plate, and then reduce the space occupied in the battery cell, thereby improving the energy density of the battery cell.

[0013] In some embodiments, the second connecting piece is provided with an opening, and the first connecting piece is embedded in the opening.

[0014] By embedding the first connecting piece into the opening of the second connecting piece, the thickness of the manufactured current collecting plate can be reduced, thereby reducing the space occupied in the battery cell, thereby improving the energy density of the battery cell.

[0015] In some embodiments, one side of the first connecting piece is connected to the second connecting piece.

[0016] One side of the first connecting piece is connected to the second connecting piece. When the first connecting piece is twisted and deformed due to welding, the second connecting piece can have less restraint on the first connecting piece, so that the first connecting piece can be better adapted to be welded with the tab, reducing the press-fitting gap between the first connecting piece and the tab and reducing the risk of cold welding.

[0017] In some embodiments, the current collecting plate further includes a folded portion, which is stacked on the second connecting piece, with one side of the folded portion connected to an edge of the second connecting piece and the other side of the folded portion connected to the first connecting piece.

[0018] A folding portion is provided to facilitate connection of the first connecting piece, and the folding portion is stacked on the second connecting piece so that the first connecting piece and the second connecting piece can at least partially overlap in thickness of the collecting plate, and the first connecting piece and the second connecting piece are connected, which facilitates the production of the collecting plate.

[0019] In some embodiments, the second connecting piece includes a main body portion and an adapting portion, the adapting portion is connected to the main body portion, the adapting portion and the folding portion are laminated together, and the thickness of the adapting portion is less than the thickness of the main body portion.

[0020] An adapter portion is provided, and its thickness is set to be smaller, so that after the folding portion and the adapter portion are stacked, the overall thickness is smaller, so that the thickness of the manufactured collecting plate is smaller, thereby reducing the space occupied in the battery cell and improving the energy density of the battery cell.

[0021] In some embodiments, the sum of the thicknesses of the folded portion and the adapting portion is less than the sum of the thicknesses of the first connecting piece and the main body portion.

[0022] Through the above structural design, the thickness of the manufactured current collecting plate can be made smaller, thereby reducing the space occupied in the battery cell, thereby improving the energy density of the battery cell.

[0023] In some embodiments, the folded portion and the second connecting piece are an integrally formed structure.

[0024] The folding portion and the second connecting piece are integrally formed to facilitate connection between the folding portion and the second connecting piece, and are also easy to process and manufacture. For example, the second connecting piece and the folding portion can be obtained by stamping a sheet of material used to make the second connecting piece, which is convenient for manufacture. In addition, when the second connecting piece is provided with an opening, the sheet of material used to make the first connecting piece can be connected to the sheet of material used to make the second connecting piece, and then the first connecting piece, the folding portion, and the second connecting piece can be stamped out. The first connecting piece can then be folded so that the first connecting piece fits into the opening of the second connecting piece, thereby obtaining a collecting tray. This is convenient to manufacture and facilitates mass production.

[0025] In some embodiments, a fold is provided at the connection between the folded portion and the second connecting piece.

[0026] A fold is provided at the connection between the second connecting piece and the folding portion to facilitate folding the folding portion onto the second connecting piece.

[0027] In some embodiments, when an opening is provided on the second connecting piece, the first connecting piece is embedded in the opening, the second connecting piece is welded to the shell to form a welding area, the welding area is arranged around the first connecting piece, and the fold is located radially outside the welding area.

[0028] The welding area formed by welding the second connecting piece to the shell is arranged around the first connecting piece, which can increase the welding area between the shell and the second connecting piece, reduce internal resistance, and improve structural strength. The fold is arranged on the radial outside of the welding area, so that the welding area of ​​the formed collecting plate can be arranged around the first connecting piece to facilitate welding to the shell.

[0029] In some embodiments, the folded portion is provided with a first thinned area, the first connecting piece is provided with a second thinned area, and the first thinned area is laminated and connected to the second thinned area;

[0030] The first thinning area is staggered with the adapting portion, and the sum of the thicknesses of the first thinning area and the second thinning area is less than the sum of the thicknesses of the first connecting piece and the main body; or, the first thinning area is at least partially stacked on the second connecting piece, and the sum of the thicknesses of the adapting portion, the first thinning area and the second thinning area is less than the sum of the thicknesses of the first connecting piece and the main body.

[0031] A first thinning area is provided on the folded portion, and a second thinning area is provided on the first connecting piece. The first thinning area and the second thinning area are stacked to facilitate connection.

[0032] The sum of the thicknesses of the first thinned area and the second thinned area is smaller than the sum of the thicknesses of the first connecting piece and the main body, so that the thickness of the collecting plate can be made smaller, thereby reducing the space occupied in the battery cell and thereby improving the energy density of the battery cell.

[0033] The sum of the thicknesses of the adapter portion, the first thinned area, and the second thinned area is less than the sum of the thicknesses of the first connecting piece and the main body, which can reduce the maximum thickness of the entire collecting plate, thereby reducing the space occupied in the battery cell and thereby improving the energy density of the battery cell.

[0034] In some embodiments, the first thinned region is connected to the second thinned region by penetration welding, or the first thinned region is connected to the second thinned region by riveting.

[0035] The first thinning area and the second thinning area are connected by penetration welding, which is convenient for connection and manufacturing.

[0036] The first thinning area is connected to the second thinning area by riveting, so that the first thinning area and the second thinning area are more firmly connected.

[0037] In some embodiments, an edge of the first connecting piece is butt-welded to the second connecting piece.

[0038] The edge of the first connecting piece is butt-welded to the second connecting piece, which is convenient for design and processing.

[0039] In some embodiments, a first stacking portion is provided on the edge of the first connecting piece, a second stacking portion is provided on the second connecting piece, the first stacking portion and the second stacking portion are stacked and connected, and the sum of the thicknesses of the first stacking portion and the second stacking portion is less than the sum of the thicknesses of the first connecting piece and the second connecting piece.

[0040] By arranging the first and second stacking parts and stacking and connecting the first and second stacking parts, the connection is convenient; and the sum of the thickness of the first and second stacking parts is smaller than the sum of the thickness of the first connecting piece and the second connecting piece, so that the thickness of the manufactured collecting plate is smaller.

[0041] In some embodiments, the first laminate portion and the second laminate portion are connected by penetration welding, or the first laminate portion and the second laminate portion are connected by riveting.

[0042] The first laminated portion and the second laminated portion are penetrated and welded or riveted to facilitate connection, thereby connecting the first connecting piece and the second connecting piece.

[0043] In some embodiments, the outer contour of the second connecting piece is circular.

[0044] The outer contour of the second connecting piece is set to be quasi-circular, so as to facilitate application in cylindrical battery cells.

[0045] In some embodiments, the opening is circular.

[0046] The opening on the second connecting piece is set to be circular so as to be applied to a cylindrical battery cell.

[0047] In some embodiments, the first connecting piece is circular in shape.

[0048] The first connecting piece is shaped into a substantially circular shape, which can facilitate the connection between the first connecting piece and the tab.

[0049] In some embodiments, a through hole is formed in the first connecting piece at the center of the opening.

[0050] A through hole is provided on the first connecting piece, which can play a positioning role when the first connecting piece is welded to the tab, and a pressure relief mechanism is provided on the side of the shell corresponding to the collecting plate. When the battery cell expands and releases pressure, the active material in the shell can be easily ejected, thereby reducing the risk of the first connecting piece blocking the pressure relief mechanism and improving the reliability of the battery cell.

[0051] In some embodiments, the through-hole is circular, oval, or polygonal.

[0052] The through hole is set to be circular, elliptical or polygonal to facilitate design and production; when the through hole is set to be polygonal and a pressure relief mechanism is provided on the side of the shell corresponding to the collecting plate, when the battery cell expands and releases pressure, the first connecting piece can be torn from the corners of the through hole to facilitate the ejection of the active material in the shell, reducing the risk of the first connecting piece blocking the pressure relief mechanism and improving the reliability of the battery cell.

[0053] In a second aspect, an embodiment of the present application provides a battery, comprising the battery cell described in the above embodiment.

[0054] In a third aspect, an embodiment of the present application provides an electrical device comprising the battery as described in the above embodiment.

[0055] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or exemplary technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0057] FIG1 is a schematic structural diagram of a vehicle according to some embodiments of the present application;

[0058] FIG2 is a schematic diagram of the exploded structure of a battery according to some embodiments of the present application;

[0059] FIG3 is a schematic cross-sectional view of a battery cell according to some embodiments of the present application;

[0060] FIG4 is a bottom view schematic diagram of the structure of a battery cell according to some embodiments of the present application;

[0061] FIG5 is a schematic structural diagram of a first current collecting plate provided in some embodiments of the present application;

[0062] FIG6 is a schematic cross-sectional view of the structure along line AA in FIG5 ;

[0063] FIG7 is a schematic structural diagram of the current collecting plate of FIG5 when it is unfolded;

[0064] FIG8 is a schematic diagram of the preparation structure of the current collecting plate shown in FIG5;

[0065] FIG9 is a schematic structural diagram of a second current collecting plate provided in some embodiments of the present application;

[0066] FIG10 is a schematic structural diagram of a third current collecting plate provided in some embodiments of the present application;

[0067] FIG11 is a schematic structural diagram of a fourth current collecting plate provided in some embodiments of the present application;

[0068] FIG12 is a schematic structural diagram of the current collecting plate of FIG11 when it is unfolded;

[0069] FIG13 is a schematic structural diagram of a fifth current collecting plate provided in some embodiments of the present application;

[0070] FIG14 is a schematic structural diagram of the current collecting plate of FIG13 when it is unfolded;

[0071] FIG15 is a schematic cross-sectional view of a sixth current collecting plate provided in some embodiments of the present application;

[0072] FIG16 is a schematic cross-sectional view of a seventh current collecting plate provided in some embodiments of the present application;

[0073] FIG17 is a schematic structural diagram of an eighth current collecting plate provided in some embodiments of the present application;

[0074] FIG18 is a schematic structural diagram of a ninth current collecting plate provided in some embodiments of the present application;

[0075] FIG19 is a schematic structural diagram of a tenth current collecting plate provided in some embodiments of the present application;

[0076] FIG20 is a schematic structural diagram of an eleventh current collecting disk provided in some embodiments of the present application;

[0077] FIG21 is a schematic structural diagram of the connection portion between the first thinned area and the second thinned area in a twelfth current collecting disk provided in some embodiments of the present application;

[0078] FIG22 is a schematic structural diagram of a thirteenth current collecting disk provided in some embodiments of the present application.

[0079] Among them, the main marks of the drawings in the figure are:

[0080] 1000-Vehicle; 1001-Battery; 1002-Controller; 1003-Motor;

[0081] 100-box; 101-first part; 102-second part;

[0082] 200 - battery cell; 21 - electrode assembly; 211 - tab; 22 - housing; 221 - shell; 2211 - cylinder; 2212 - bottom cover; 222 - end cover;

[0083] 30-collecting plate; 31-first connecting piece; 310-through hole; 311-second thinning area; 312-second hole position; 313-first stacking portion; 314-first mounting hole; 32-second connecting piece; 320-opening; 321-main body; 322-adapting portion; 323-second stacking portion; 324-second mounting hole; 3201-welding area; 33-folding portion; 331-first thinning area; 332-first hole position; 34-crease; 35-first rivet column; 36-second rivet column; 301-first plate; 302-second plate. DETAILED DESCRIPTION

[0084] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0085] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0086] In the description of the embodiments of this application, the technical terms "first," "second," etc., are used solely to distinguish between different objects and should not be understood to indicate or imply relative importance, or to implicitly specify the quantity, specific order, or primary-secondary relationship of the technical features indicated. Therefore, a feature designated "first" or "second" may explicitly or implicitly include one or more of such features.

[0087] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments in any suitable manner.

[0088] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0089] In the description of the embodiments of this application, the term "plurality" refers to two or more (including two). Similarly, "multiple groups" refers to two or more (including two groups), and "multiple sheets" refers to two or more (including two sheets). "Several" means one or more, unless otherwise specifically defined.

[0090] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limiting the embodiments of the present application.

[0091] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0092] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, when an element is referred to as being “fixed to” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0093] In the description of the embodiments of this application, unless otherwise explicitly specified or limited, the technical term "adjacent" refers to proximity in position. For example, if there are three components A1, A2, and B, and the distance between A1 and B is greater than the distance between A2 and B, then A2 is closer to B than A1, that is, A2 is adjacent to B, or B is adjacent to A2. For another example, if there are multiple C components, namely C1, C2, ..., CN, and one C component, such as C2, is closer to B than the other C components, then B is adjacent to C2, or C2 is adjacent to B.

[0094] In the embodiments of the present application, battery cells include, but are not limited to, lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries. The shapes of battery cells include, but are not limited to, cylinders, elliptical cylinders, hexagonal prisms, or other shapes. In the embodiments of the present application, the battery cells are primarily described using cylindrical battery cells.

[0095] The battery mentioned in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in this application may include a battery module or a battery pack. The battery generally includes a casing for encapsulating one or more battery cells. The casing can, to a certain extent, prevent liquids or other foreign matter from affecting the charging or discharging of the battery cells. In some cases, the battery cells can also be used directly, that is, the battery may not include a casing, which is not limited here.

[0096] In a battery, when there are multiple battery cells, they can be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections. Multiple battery cells can be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell structure is housed within a housing. Alternatively, a battery can be constructed by first connecting multiple battery cells in series, in parallel, or in a hybrid connection to form a battery module, which is then connected in series, in parallel, or in a hybrid connection to form a single unit, which is then housed within a housing. The battery may also include other structures, such as a busbar assembly for electrically connecting multiple battery cells.

[0097] The battery cell in the embodiment of the present application includes an electrode assembly and a shell. The shell includes an end cover and a shell. The electrode assembly is installed in the shell. The end cover is covered on the shell, and the shell is filled with electrolyte.

[0098] The electrode assembly is also called a battery cell. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet and a separator. The electrode assembly mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The part of the positive electrode collector that is not coated with the positive electrode active material layer protrudes from the part that is coated with the positive electrode active material layer. The part that is not coated with the positive electrode active material layer serves as the positive electrode tab, or a metal conductor is welded on the positive electrode collector and led out to serve as the positive electrode tab. Taking lithium-ion batteries as an example, the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The portion of the negative electrode current collector not coated with the negative electrode active material layer protrudes from the portion coated with the negative electrode active material layer. The portion not coated with the negative electrode active material layer serves as the negative electrode tab. Alternatively, a metal conductor is welded to the negative electrode current collector and extended to serve as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative electrode active material can be carbon, silicon, or other materials.

[0099] The electrode assembly can be a wound structure. The wound structure usually involves welding the tabs to the current collector, which are then arranged in the order of positive electrode sheet - separator - negative electrode sheet - separator; and then wound to form a cylindrical or other columnar shape. The separator can be made of PP (Polypropylene) or PE (Polyethylene), etc. The separator is an insulating film provided between the positive and negative electrodes. Its main function is to isolate the positive and negative electrodes and prevent electrons in the battery from passing freely to prevent short circuits, while allowing ions in the electrolyte to pass freely between the positive and negative electrodes to form a circuit between the positive and negative electrodes. The positive and negative electrodes are collectively referred to as electrodes. The positive and negative electrode tabs are collectively referred to as tabs.

[0100] After the electrode assembly is manufactured, it needs to be placed in a housing and filled with electrolyte to immerse the electrode assembly and fully absorb the electrolyte. The electrolyte provides some active ions that serve as conductive ions during the charge and discharge process. In addition, the electrolyte provides ion channels, or carriers, allowing ions to move freely through them, thereby achieving electrical conduction between the electrodes.

[0101] To facilitate the charging and discharging of battery cells, they are often equipped with electrode terminals. Electrode terminals are conductive components located on the outer casing of a battery cell. These terminals are connected to the tabs of the electrode assembly to output electrical energy from the battery cell or charge the battery cell. A battery cell typically has two electrode terminals, one connected to the positive and negative tabs of the electrode assembly. The electrode terminal connected to the positive tab is the positive electrode terminal, and the electrode terminal connected to the negative tab is the negative electrode terminal.

[0102] An end cap is a component that covers the opening of the battery housing to isolate the internal environment of the battery cell from the external environment. The shape of the end cap can be adapted to the shape of the housing to ensure a secure fit. Optionally, the end cap can be made of a material with a certain degree of hardness and strength (such as aluminum alloy). This makes the end cap less likely to deform during compression and collision, providing the battery cell with greater structural strength and improved reliability.

[0103] The shell is a component used to cooperate with the end cap to form the internal environment of the battery cell, wherein the formed internal environment can be used to accommodate the electrode assembly, electrolyte and other components. The shell and the end cap can be independent components, and an opening can be provided on the shell so that the end cap covers the opening to form the internal environment of the battery cell. The shell can be of various shapes and sizes, such as cylindrical, hexagonal, etc. Specifically, the shape of the shell can be determined according to the specific shape and size of the battery cell. The shell can be made of various materials, including but not limited to iron, aluminum, stainless steel, aluminum alloy, etc.

[0104] For cylindrical battery cells, the shell generally includes a barrel and a bottom cover. The bottom cover is covered on one end of the barrel, and the end cover is covered on the other end of the barrel to form the outer shell of the battery cell. The bottom of the shell refers to the end of the shell away from the end cover. For a shell including a barrel and a bottom cover, the bottom of the shell is generally the bottom cover. For cylindrical battery cells, the bottom of the shell is often used as the negative electrode, that is, the bottom cover is used as the negative electrode. The barrel refers to the cylindrical shell structure that forms the main part of the shell, and the bottom cover refers to the cover structure that covers one end of the barrel. The bottom cover is covered on one end of the barrel to form the shell structure. The bottom cover and the barrel can be made separately and then welded together. Of course, the bottom cover and the barrel can also be formed in one piece.

[0105] The bottom of the battery cell shell is used as the negative electrode, and the negative electrode of the electrode assembly needs to be led out to the shell. For example, the negative electrode tab needs to be welded to the shell to form a guide structure, especially welded to the bottom cover to form a guide structure. However, the material of the negative electrode tab of the electrode assembly is generally copper, while the material of the shell is generally steel shell, aluminum alloy, etc. Because the tab material is different from the shell material, the expansion coefficients of different materials during welding are also different, which makes it easy to generate welding cracks or damage the electrode assembly during welding. To solve this problem, a current collecting plate structure with two materials stacked and composited is currently used. For example, a layer of copper sheet and a layer of steel sheet are stacked and composited, and the copper sheet is welded to the tab, and the steel sheet is welded to the shell to reduce the risk of welding cracks. However, this stacked composite structure takes up a lot of space and will reduce the energy density of the battery.

[0106] Based on the above considerations, in order to solve the problem that the stacked composite current collecting plate occupies a large space and will reduce the energy density of the battery, an embodiment of the present application provides a battery cell, which is formed into a current collecting plate by connecting a first connecting plate with a second connecting plate, so that the first connecting plate is welded to the pole ear of the battery cell, and the second connecting plate is welded to the shell of the battery cell, thereby reducing the risk of welding cracks; and the thickness of the manufactured current collecting plate is such that the first connecting plate and the second connecting plate at least partially overlap, so as to reduce the thickness of the current collecting plate, thereby reducing the space occupied in the battery cell, thereby improving the energy density of the battery cell.

[0107] The battery cells disclosed in the embodiments of the present application can be used in electrical devices that use batteries as power sources or various energy storage systems that use batteries as energy storage elements, such as energy storage power supply systems for hydropower, thermal power, wind power, and solar power stations. Electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, electric tools, electric bicycles, electric motorcycles, electric cars, ships, spacecraft, and the like. Among them, electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like, and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, and the like.

[0108] For the convenience of description, an electric device is provided in accordance with an embodiment of the present application, and the electric device is described by taking a vehicle as an example.

[0109] Please refer to Figure 1, which is a schematic structural diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 1001 is provided inside the vehicle 1000, and the battery 1001 can be provided at the bottom, head or tail of the vehicle 1000. The battery 1001 can be used to power the vehicle 1000. For example, the battery 1001 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 1002 and a motor 1003. The controller 1002 is used to control the battery 1001 to power the motor 1003, for example, for starting, navigating and driving the vehicle 1000.

[0110] In some embodiments of the present application, the battery 1001 can serve not only as an operating power source for the vehicle 1000, but also as a 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 a schematic diagram of the exploded structure of a battery 1001 provided in some embodiments of the present application. The battery 1001 includes a housing 100 and a battery cell, which is housed within the housing 100. The housing 100 is used to provide a storage space for the battery cell, and the housing 100 can adopt a variety of structures. In some embodiments, the housing 100 can include a first portion 101 and a second portion 102, the first portion 101 and the second portion 102 covering each other, and the first portion 101 and the second portion 102 jointly define a storage space for accommodating the battery cell. The second portion 102 can be a hollow structure with one end open, and the first portion 101 can be a plate-like structure, with the first portion 101 covering the open side of the second portion 102, so that the first portion 101 and the second portion 102 jointly define a storage space; the first portion 101 and the second portion 102 can also be hollow structures with one end open, with the open side of the first portion 101 covering the open side of the second portion 102. Of course, the box 100 formed by the first part 101 and the second part 102 can be of various shapes, such as a cylinder, a cuboid, etc. After multiple battery cells are connected in parallel, in series, or in a mixed combination, they are placed in the box 100 formed by the first part 101 and the second part 102 being fastened together.

[0112] Please refer to Figures 3 to 8. Figure 3 is a schematic diagram of the cross-sectional structure of the battery cell 200 according to some embodiments of the present application. Figure 4 is a schematic diagram of the bottom-up structure of the battery cell 200 according to some embodiments of the present application. Figure 5 is a schematic diagram of the structure of the current collecting tray 30 provided in some embodiments of the present application. Figure 6 is a schematic diagram of the cross-sectional structure along line AA in Figure 5. Figure 7 is a schematic diagram of the structure of the current collecting tray 30 in Figure 5 when it is unfolded. Figure 8 is a schematic diagram of the structure of the current collecting tray 30 shown in Figure 5 during a process of manufacturing.

[0113] An embodiment of the present application provides a battery cell 200, including: a shell 221; an electrode assembly 21, installed in the shell 221, and provided with a pole ear 211 on the electrode assembly 21; a current collecting plate 30, including a first connecting plate 31 and a second connecting plate 32, the first connecting plate 31 is connected to the second connecting plate 32, the first connecting plate 31 is welded to the pole ear 211, and the second connecting plate 32 is welded to the shell 221; along the thickness direction perpendicular to the second connecting plate 32, the projection of the first connecting plate 31 and the projection of the second connecting plate 32 at least partially overlap.

[0114] The housing 221 is a portion of the outer shell 22 of the battery cell 200. The outer shell 22 includes the housing 221 and an end cap 222. The end cap 222 covers the opening of the housing 221 to isolate the internal environment of the battery cell 200 from the external environment. The housing 221 is used in conjunction with the end cap 222 to form the internal environment of the battery cell 200. This internal environment can be used to accommodate the electrode assembly 21, electrolyte, and other components.

[0115] The electrode assembly 21 is mounted in the housing 221, which houses and protects the electrode assembly 21. The electrode assembly 21 is provided with a tab 211, which is connected to the housing 221 to allow current to flow between the housing 221 and the tab 211. In some embodiments, when the housing 221 serves as the negative electrode of the battery cell 200, the tab 211 is the negative electrode tab. Of course, it is not ruled out that some battery cells 200 use the housing 221 as the positive electrode, in which case the tab 211 is the positive electrode tab.

[0116] The current collecting plate 30 is a conductive structure that connects the housing 221 and the tab 211 to enable current to flow between the housing 221 and the tab 211 .

[0117] The first connecting piece 31 is a sheet-like conductive member on the current collecting plate 30 that is welded to the tab 211. The first connecting piece 31 is provided to facilitate welding to the tab 211, thereby reducing the risk of welding cracks. The first connecting piece 31 can be made of the same material as the tab 211 to reduce the risk of welding cracks. Of course, the first connecting piece 31 can also be made of a material that is easily welded to the tab 211 to reduce the risk of welding cracks. For example, if the tab 211 is copper, the first connecting piece 31 can also be made of copper.

[0118] The second connecting piece 32 refers to a sheet-like conductive part on the collecting plate 30 that is welded to the shell 221. The second connecting piece 32 is provided to facilitate welding with the shell 221 to reduce the risk of welding cracks. The material of the second connecting piece 32 can be the same as the material of the shell 221 to reduce the risk of welding cracks. Of course, the second connecting piece 32 can also be made of a material that is easy to weld with the shell 221 to reduce the risk of welding cracks. For example, when the shell 221 is made of steel, the second connecting piece 32 can also be made of steel. The second connecting piece 32 can also be made of materials such as nickel. For example, when the shell 221 is made of aluminum alloy, the second connecting piece 32 can also be made of aluminum alloy.

[0119] The first connecting piece 31 is connected to the second connecting piece 32 so that current can flow between the first connecting piece 31 and the second connecting piece 32. The first connecting piece 31 and the second connecting piece 32 are formed into the current collecting plate 30. The current collecting plate 30 can be manufactured separately to ensure a stable and reliable connection between the first connecting piece 31 and the second connecting piece 32, so that the current collecting plate 30 has good current conducting capability and reliability.

[0120] The first connecting piece 31 is welded to the tab 211 , which can improve the stability of welding, reduce the risk of welding cracks, and reduce the risk of damage to the tab 211 and the electrode assembly 21 , thereby improving the conductivity and reliability of current between the first connecting piece 31 and the tab 211 .

[0121] The second connecting piece 32 is welded to the housing 221 , which can improve welding stability, reduce the risk of welding cracks, and improve the conductivity and reliability of current between the second connecting piece 32 and the housing 221 .

[0122] The thickness direction of the second connecting piece 32 is consistent with the thickness direction of the first connecting piece 31 , and the thickness direction of the second connecting piece 32 is consistent with the thickness direction of the current collecting plate 30 .

[0123] Along the thickness direction perpendicular to the second connecting piece 32, the projection of the first connecting piece 31 and the projection of the second connecting piece 32 at least partially overlap, which means that the projection of the first connecting piece 31 perpendicular to the thickness direction and the projection of the second connecting piece 32 perpendicular to the thickness direction partially overlap or completely overlap.

[0124] Since the observation and measurement of the thickness of the collecting plate 30 need to be carried out in a thickness direction perpendicular to the collecting plate 30, the projection of the first connecting plate 31 and the projection of the second connecting plate 32 at least partially overlap along the thickness direction perpendicular to the second connecting plate 32. Then, in the thickness direction of the collecting plate 30, the first connecting plate 31 and the second connecting plate 32 at least partially overlap, which makes the overall thickness of the manufactured collecting plate 30 smaller than the sum of the thicknesses of the first connecting plate 31 and the second connecting plate 32, thereby reducing the thickness of the manufactured collecting plate 30. When applied to the battery cell 200, the space occupied in the outer shell 22 of the battery cell 200 can be reduced, thereby improving the energy density of the manufactured battery cell 200.

[0125] In the technical solution of the embodiment of the present application, the first connecting piece 31 and the second connecting piece 32 are connected to form a current collecting plate 30, so that the first connecting piece 31 is welded to the pole ear 211 of the battery cell 200, and the second connecting piece 32 is welded to the shell 221 of the battery cell 200, so that the current collecting plate 30 is connected to the shell 221 and the pole ear 211, thereby improving the stability and reliability of the connection; in the thickness perpendicular to the second connecting piece 32, the projection of the first connecting piece 31 and the projection of the second connecting piece 32 are at least partially overlapped, so that in the thickness of the manufactured current collecting plate 30, the first connecting piece 31 and the second connecting piece 32 are at least partially overlapped, which can reduce the thickness of the current collecting plate 30, and then reduce the space occupied in the battery cell 200, thereby improving the energy density of the battery cell 200.

[0126] In some embodiments, the housing 221 includes a cylinder 2211 and a bottom cover 2212 . The bottom cover 2212 covers one end of the cylinder 2211 , and the second connecting piece 32 is welded to the bottom cover 2212 .

[0127] The cylinder 2211 refers to the cylindrical shell structure that forms the main part of the shell 221, and the bottom cover 2212 refers to the cover structure covering one end of the cylinder 2211. The bottom cover 2212 covers one end of the cylinder 2211 to form the shell 221 structure. The bottom cover 2212 and the cylinder 2211 can be made separately and then welded together. Of course, the bottom cover 2212 and the cylinder 2211 can also be formed in one piece. The bottom cover 2212 and the end cover 222 are respectively covered at both ends of the cylinder 2211 to form the outer shell 22 of the battery cell 200. The bottom of the shell 221 refers to the end of the shell 221 away from the end cover 222. For the shell 221 including the cylinder 2211 and the bottom cover 2212, the bottom of the shell 221 refers to the bottom cover 2212.

[0128] The second connecting piece 32 is welded to the bottom cover 2212 to realize welding the second connecting piece 32 to the shell 221 , which is convenient for connection and easy for processing and manufacturing.

[0129] In some embodiments, an opening 320 is defined in the second connecting piece 32 , and the first connecting piece 31 is embedded in the opening 320 .

[0130] The opening 320 is a through-hole structure provided on the second connecting piece 32 and passing through the thickness of the second connecting piece 32 .

[0131] The first connecting piece 31 is embedded in the opening 320, which means that the first connecting piece 31 extends entirely or at least partially into the opening 320. Since the first connecting piece 31 is embedded in the opening 320, the first connecting piece 31 and the second connecting piece 32 at least partially overlap in the thickness direction of the current collecting plate 30, which facilitates design and processing.

[0132] By embedding the first connecting piece 31 into the opening 320 of the second connecting piece 32 , the thickness of the current collecting plate 30 can be reduced, thereby reducing the space occupied in the battery cell 200 and improving the energy density of the battery cell 200 .

[0133] In some embodiments, one side of the first connecting piece 31 is connected to the second connecting piece 32 .

[0134] One side of the first connecting piece 31 refers to a section of the circumference of the first connecting piece 31 , and the side of the first connecting piece 31 where the section is located is one side of the first connecting piece 31 .

[0135] One side of the first connecting piece 31 is connected to the second connecting piece 32 , which means that a section of the circumference of the first connecting piece 31 is connected to the second connecting piece 32 .

[0136] When the first connecting piece 31 is welded to the tab 211, the first connecting piece 31 will be twisted and deformed. If the entire circumference of the first connecting piece 31 is connected to the second connecting piece 32, such as the first connecting piece 31 is placed in the opening 320 of the second connecting piece 32, and the four circumferential sides of the first connecting piece 31 are connected to the second connecting piece 32, then the four circumferential sides of the first connecting piece 31 will be constrained by the second connecting piece 32. This will cause the twisting deformation caused by the welding of the first connecting piece 31 and the tab 211 to reduce the fit between the first connecting piece 31 and the tab 211, resulting in a press-fit gap between the first connecting piece 31 and the tab 211, and increasing the risk of cold welding.

[0137] The press-fit gap refers to the gap between two structural components when they are pressed against each other. The press-fit gap between the first connecting piece 31 and the tab 211 refers to the gap between the first connecting piece 31 and the tab 211 when they are pressed against each other for welding. The larger the press-fit gap, the worse the stability of the weld between the first connecting piece 31 and the tab 211, and the more likely it is to cause a cold weld. The smaller the press-fit gap, the tighter the fit between the first connecting piece 31 and the tab 211, the stronger the weld, and the better the weld quality.

[0138] Only one side of the first connecting piece 31 is connected to the second connecting piece 32, so that only one side of the first connecting piece 31 is constrained by the second connecting piece 32. When the first connecting piece 31 is welded to the pole tab 211, the first connecting piece 31 can better adapt to distortion and increase the fit with the pole tab 211, thereby reducing the press-fit gap between the first connecting piece 31 and the pole tab 211 to reduce the risk of cold welding.

[0139] One side of the first connecting piece 31 is connected to the second connecting piece 32. When the first connecting piece 31 is twisted and deformed due to welding, the second connecting piece 32 can have less restraint on the first connecting piece 31, so that the first connecting piece 31 can be better adapted to be welded with the tab 211, thereby reducing the press-fitting gap between the first connecting piece 31 and the tab 211 and reducing the risk of cold welding.

[0140] In some embodiments, the current collecting plate 30 further includes a folded portion 33 , which is stacked on the second connecting piece 32 . One side of the folded portion 33 is connected to an edge of the second connecting piece 32 , and the other side of the folded portion 33 is connected to the first connecting piece 31 .

[0141] The folded portion 33 is a portion of the sheet-like conductive structure that connects the second connecting piece 32 and the first connecting piece 31. When the folded portion 33 is unfolded, the second connecting piece 32 and the first connecting piece 31 are located on opposite sides of the folded portion 33. When the folded portion 33 is folded onto the second connecting piece 32, the second connecting piece 32 is located on one side of the folded portion 33, and the first connecting piece 31 is located on one side of the folded portion 33 in the thickness direction.

[0142] The edge of the second connecting sheet 32 ​​refers to the edge of the second connecting sheet 32 ​​on a side away from the first connecting sheet 31 when the folded portion 33 is stacked on the second connecting sheet 32 ​​.

[0143] One side of the folding portion 33 is connected to the edge of the second connecting piece 32, and the other side of the folding portion 33 is connected to the first connecting piece 31. After the folding portion 33 is folded onto the second connecting piece 32, the first connecting piece 31 can be located on the other side opposite to the side where the folding portion 33 is connected to the second connecting piece 32.

[0144] A folding portion 33 is provided to facilitate connection of the first connecting piece 31 , and the folding portion 33 is stacked on the second connecting piece 32 so that the first connecting piece 31 and the second connecting piece 32 can at least partially overlap in the thickness of the collecting plate 30 , and the first connecting piece 31 and the second connecting piece 32 are connected to facilitate the manufacture of the collecting plate 30 .

[0145] In some embodiments, the second connecting piece 32 includes a main body 321 and an adapting portion 322 . The adapting portion 322 is connected to the main body 321 . The adapting portion 322 is stacked with the folding portion 33 . The thickness of the adapting portion 322 is less than that of the main body 321 .

[0146] The adapting portion 322 refers to the partial area on the second connecting piece 32 that is overlapped with the folding portion 33 , that is, the folding portion 33 is folded on the adapting portion 322 , and the main body 321 is the partial area on the second connecting piece 32 excluding the adapting portion 322 .

[0147] The thickness of the adapting portion 322 is smaller than the thickness of the main body 321. Thus, after the folding portion 33 is folded onto the adapting portion 322, the sum of the thicknesses of the folding portion 33 and the adapting portion 322 will be smaller than the sum of the thicknesses of the folding portion 33 and the main body 321, thereby making the overall thickness of the manufactured collecting tray 30 smaller.

[0148] An adapter portion 322 is provided, and the thickness of the adapter portion 322 is set to be relatively small, so that after the folding portion 33 and the adapter portion 322 are stacked, the overall thickness is relatively small, so that the thickness of the manufactured collecting plate 30 is relatively small, thereby reducing the space occupied in the battery cell 200 and improving the energy density of the battery cell 200.

[0149] In some embodiments, the sum of the thicknesses of the folding portion 33 and the adapting portion 322 is less than the sum of the thicknesses of the first connecting piece 31 and the main body portion 321 .

[0150] Since the thickness of the adapting portion 322 is smaller than the thickness of the main body 321, and along the thickness direction perpendicular to the collecting plate 30, the projection of the first connecting piece 31 and the projection of the second connecting piece 32 at least partially overlap, the projection of the first connecting piece 31 and the projection of the main body 321 at least partially overlap, so that the overall thickness of the collecting plate 30 is smaller than the sum of the thicknesses of the first connecting piece 31 and the main body 321.

[0151] The folding portion 33 is folded onto the adapting portion 322, and the sum of the thicknesses of the folding portion 33 and the adapting portion 322 is set to be smaller than the sum of the thicknesses of the first connecting piece 31 and the main body 321. This allows the sum of the thicknesses of the folding portion 33 and the adapting portion 322 to be less than or equal to the maximum thickness of the entire collecting plate 30, so that the stacking cooperation of the folding portion 33 and the adapting portion 322 will not affect the overall thickness of the collecting plate 30, so that the overall thickness of the collecting plate 30 can be made smaller.

[0152] Through the above structural design, the thickness of the current collecting plate 30 can be made smaller, thereby reducing the space occupied in the battery cell 200 and improving the energy density of the battery cell 200.

[0153] In some embodiments, the folding portion 33 and the second connecting piece 32 are an integrally formed structure.

[0154] The folding portion 33 and the second connecting piece 32 are an integrally formed structure, which means that the folding portion 33 and the second connecting piece 32 are made of the same conductive sheet to facilitate processing and manufacturing. For example, the folding portion 33 and the second connecting piece 32 can be connected by stamping a sheet of the material used to make the second connecting piece 32.

[0155] The folding portion 33 and the second connecting piece 32 are integrally formed to facilitate connection between the folding portion 33 and the second connecting piece 32 and to facilitate processing and manufacturing. For example, the second connecting piece 32 and the folding portion 33 can be obtained by stamping a sheet of material used to make the second connecting piece 32, which is convenient for manufacturing.

[0156] In some embodiments, the first plate 301 and the second plate 302 can be connected to form a larger plate. The first plate 301 can be made of the material used to make the first connecting piece 31, and the second plate 302 can be made of the material used to make the second connecting piece 32. The entire plate formed by connecting the first plate 301 and the second plate 302 is stamped to form the first connecting piece 31, the folded portion 33, and the second connecting piece 32. The folded portion 33 is then folded onto the second connecting piece 32 to form the collecting tray 30. This structure facilitates batch processing and can effectively reduce production costs.

[0157] In some embodiments, when an opening 320 is provided on the second connecting piece 32, the sheet plate of the material for making the first connecting piece 31 can be connected to the sheet plate of the material for making the second connecting piece 32, that is, after the above-mentioned first plate 301 is connected to the second plate 302, the first connecting piece 31, the folding portion 33 and the second connecting piece 32 are punched out, and then folded so that the first connecting piece 31 is embedded in the opening 320 of the second connecting piece 32, and the collecting plate 30 is obtained, which is easy to manufacture and convenient for mass production.

[0158] In some embodiments, the first plate 301 may be welded to the second plate 302 to facilitate connection.

[0159] In some embodiments, the first plate 301 may be connected to the second plate 302 by riveting to reduce the risk of welding cracks and ensure that the first plate 301 and the second plate 302 are firmly connected.

[0160] In some embodiments, when the first connecting piece 31 is located on one side of the second connecting piece 32 and the side of the first connecting piece 31 is connected to the second connecting piece 32, the entire plate formed by connecting the first plate 301 and the second plate 302 can be directly stamped to form the collecting plate 30, which is convenient for batch production and reduces costs.

[0161] In some embodiments, a fold 34 is formed at the connection between the folding portion 33 and the second connecting piece 32 .

[0162] The connection point between the folded portion 33 and the second connecting piece 32 refers to the position where the folded portion 33 is connected to the second connecting piece 32 .

[0163] The fold mark 34 is a mark for folding, such as a long, concave groove provided on the sheet. The fold mark 34 is provided at the connection between the folding portion 33 and the second connecting piece 32. That is, the folding portion 33 and the second connecting piece 32 are provided with a folding mark to facilitate folding the folding portion 33 onto the second connecting piece 32 at the fold mark 34.

[0164] A fold 34 is provided at the connection between the second connecting piece 32 and the folding portion 33 to facilitate folding the folding portion 33 onto the second connecting piece 32 .

[0165] In some embodiments, when an opening 320 is provided on the second connecting piece 32, the first connecting piece 31 is embedded in the opening 320, and the second connecting piece 32 is welded to the shell 221 to form a welding area 3201. The welding area 3201 is arranged around the first connecting piece 31, and the fold 34 is located radially outside the welding area 3201.

[0166] The second connecting piece 32 is provided with an opening 320, and the first connecting piece 31 is embedded in the opening 320, so that the second connecting piece 32 can be arranged around the first connecting piece 31, so that when the second connecting piece 32 is welded to the shell 221, the welding area of ​​the second connecting piece 32 and the shell 221 is increased, thereby improving the firmness and reliability of the welding of the second connecting piece 32 and the shell 221 and reducing the internal resistance.

[0167] The welding area 3201 is arranged around the first connecting piece 31, which can further increase the welding area of ​​the second connecting piece 32 and the shell 221, thereby improving the firmness and reliability of the welding between the second connecting piece 32 and the shell 221 and reducing the internal resistance.

[0168] The fold 34 is located radially outside the welding area 3201, so that when the second connecting piece 32 is welded to the shell 221, the welding area will not extend to the outside of the second connecting piece 32, which not only improves the welding quality but also provides good protection for the electrode assembly 21.

[0169] The welding area 3201 formed by welding the second connecting piece 32 to the shell 221 is arranged around the first connecting piece 31, which can increase the welding area between the shell 221 and the second connecting piece 32, reduce internal resistance, and improve structural strength. The fold 34 is arranged radially outside the welding area 3201, so that the welding area 3201 of the formed collecting plate 30 can be arranged around the first connecting piece 31 to facilitate welding to the shell 221.

[0170] In some embodiments, the shape of the welding area 3201 matches the shape of the second connecting piece 32. That is, if the second connecting piece 32 is circular, the welding area 3201 can be circular to facilitate welding and increase the area of ​​the welding area 3201. If the second connecting piece 32 is elliptical, the welding area 3201 can be elliptical. If the second connecting piece 32 is quasi-circular, the welding area 3201 can be quasi-circular.

[0171] When a planar structure, sheet structure, or plate-like structure has a majority of its circumference in an arc shape, such as more than 2 / 3, more than 3 / 5, more than 4 / 7, more than 6 / 11, more than 7 / 13, etc., while the rest of the area is linear, the shape of this structure is defined as quasi-circular. If the majority of the outer circumference of a structural component is in an arc shape, and these arcs lie on the same circle, the shape of the structural component is considered quasi-circular. Of course, a circle can also be called a special type of quasi-circular.

[0172] Please refer to Figures 5, 9, 10, and 13. Figure 9 is a schematic diagram of the structure of the current collecting tray 30 provided in some embodiments of the present application. Figure 10 is a schematic diagram of the structure of the current collecting tray 30 provided in other embodiments of the present application. Figure 13 is a schematic diagram of the structure of the current collecting tray 30 provided in still other embodiments of the present application.

[0173] In some embodiments, the first connecting piece 31 is adapted to the size of the opening 320. For example, when the opening 320 on the second connecting piece 32 is set to be circular, the first connecting piece 31 is set to be quasi-circular, and the diameter of the first connecting piece 31 is equal to or slightly smaller than the diameter of the opening 320, so that the first connecting piece 31 can be embedded in the opening 320. In addition, this structure can set the area of ​​the first connecting piece 31 to be larger to increase the welding area with the pole ear 211, reduce the internal resistance, and improve the current conduction capability.

[0174] In some embodiments, the welding area 3201 between the collecting plate 30 and the shell 221 passes through the folding portion 33, that is, not only the second connecting piece 32 is welded to the shell 221, but the folding portion 33 is also welded to the shell 221, so as to increase the welding area between the collecting plate 30 and the shell 221, improve the firmness and reliability of the welding, reduce the internal resistance, and facilitate the passage of current.

[0175] Please refer to Figures 5, 9 to 11. Figure 9 is a schematic diagram of the structure of the current collecting tray 30 provided in some embodiments of the present application. Figure 10 is a schematic diagram of the structure of the current collecting tray 30 provided in other embodiments of the present application. Figure 11 is a schematic diagram of the structure of the current collecting tray 30 provided in still other embodiments of the present application.

[0176] In some embodiments, a through hole 310 is defined at the center of the collecting plate 30 .

[0177] The through hole 310 refers to a hole structure that penetrates the structural member.

[0178] The center position of the collecting plate 30 refers to the geometric center position of the collecting plate 30. For example, when the collecting plate 30 is circular, the center position of the collecting plate 30 is the center of the collecting plate 30. When the collecting plate 30 is a regular polygon, the center position of the collecting plate 30 is the symmetric center of the collecting plate 30.

[0179] A through hole 310 is provided at the center of the collecting plate 30 , which can play a positioning role when assembling the collecting plate 30 , facilitating welding of the first connecting piece 31 of the collecting plate 30 to the tab 211 and the second connecting piece 32 of the collecting plate 30 to the housing 221 .

[0180] In some embodiments, the through hole 310 is circular, elliptical, or polygonal. The through hole 310 is configured as a circular, elliptical, or polygonal shape to facilitate design and production.

[0181] Please refer to Figures 11, 17 to 20. Figure 11 is a schematic diagram of the structure of the current collecting tray 30 provided in some embodiments of the present application. Figure 17 is a schematic diagram of the structure of the current collecting tray 30 provided in other embodiments of the present application. Figure 18 is a schematic diagram of the structure of the current collecting tray 30 provided in still other embodiments of the present application. Figure 19 is a schematic diagram of the structure of the current collecting tray 30 provided in still other embodiments of the present application. Figure 20 is a schematic diagram of the structure of the current collecting tray 30 provided in still other embodiments of the present application.

[0182] In some embodiments, the size of the first connecting piece 31 is smaller than the size of the opening 320. For example, when the opening 320 on the second connecting piece 32 is set to be circular, the first connecting piece 31 is set to be quasi-circular, and the diameter of the first connecting piece 31 is smaller than the diameter of the opening 320. When the first connecting piece 31 is embedded in the opening 320, the edge of the first connecting piece 31 is spaced apart from the inner side of the opening 320 of the second connecting piece 32 to facilitate placing the first connecting piece 31 in the opening 320 of the second connecting piece 32.

[0183] Please refer to Figures 5 and 7. In some embodiments, the fold 34 can be set at the edge of the opening 320. For example, if the opening 320 is set to be circular, the fold 34 is tangent to the opening 320. In this way, the area of ​​the folding portion 33 can be set to be smaller to reduce material usage and reduce costs. In addition, the connection length between the first connecting piece 31 and the folding portion 33 can be set to be larger to reduce the resistance between the first connecting piece 31 and the folding portion 33 and improve the ability of current conduction between the first connecting piece 31 and the folding portion 33.

[0184] Please refer to Figures 11 and 12. Figure 12 is a schematic diagram of the structure of the collecting plate 30 of Figure 11 when it is unfolded. In some embodiments, the opening 320 on the second connecting piece 32 is arranged in a quasi-circular shape, the fold 34 is tangent to the circle where the arc edge of the opening 320 is located, and the fold 34 is spaced apart from the arc edge of the opening 320. This allows the area of ​​the adapter portion 322 to be set larger to better support the folded portion 33, and the adapter portion 322 and the folded portion 33 can be stacked and connected, such as by welding the adapter portion 322 and the folded portion 33, or by riveting the adapter portion 322 and the folded portion 33 to improve the connection strength between the folded portion 33 and the adapter portion 322. In addition, with this structure, when welding the adapter portion 322 to the shell 221, the folded portion 33, the adapter portion 322, and the shell 221 can be welded together to increase the connection strength, and the folded portion 33 and the adapter portion 322 can be welded together.

[0185] In some embodiments, an opening 320 is provided on the second connecting piece 32, and the fold 34 is provided tangent to the circle where the arc-shaped edge of the opening 320 is located, or when the fold 34 is provided adjacent to the circle where the arc-shaped edge of the opening 320 is located, the welding area 3201 where the second connecting piece 32 is welded to the shell 221 is quasi-circular, and the welding area 3201 will pass through the folding portion 33 to weld the folding portion 33 and the adapter portion 322 to the shell 221 to increase the welding area and stability.

[0186] Please refer to Figures 13 and 14. Figure 13 is a schematic diagram of the structure of the current collecting tray 30 provided in some embodiments of the present application. Figure 14 is a schematic diagram of the structure of the current collecting tray 30 of Figure 13 when it is unfolded.

[0187] In some embodiments, an opening 320 is provided on the second connecting piece 32, the first connecting piece 31 is embedded in the opening 320, the second connecting piece 32 is welded to the shell 221 to form a welding area 3201, the welding area 3201 where the second connecting piece 32 is welded to the shell 221 is circular, and the fold 34 is located radially outside the welding area 3201.

[0188] The circular setting of the welding area 3201 not only facilitates welding, but also increases the welding area between the second connecting piece 32 and the shell 221, thereby improving the firmness and reliability of the welding between the second connecting piece 32 and the shell 221 and reducing internal resistance.

[0189] The fold 34 is located radially outside the welding area 3201 so that the folded portion 33 is folded onto the second connecting piece 32 , and the welding area 3201 where the second connecting piece 32 is welded to the housing 221 can be set to be circular.

[0190] The welding area 3201 formed by welding the second connecting piece 32 to the shell 221 is set to be circular, which can increase the welding area between the shell 221 and the second connecting piece 32, reduce internal resistance, and improve structural strength. The fold 34 is set on the radial outside of the welding area 3201, so that the welding area 3201 of the formed collecting plate 30 can be formed into a ring, so as to facilitate welding to the shell 221.

[0191] In some embodiments, referring to FIG. 5 to FIG. 8 , the folded portion 33 and the first connecting piece 31 are connected by butt welding.

[0192] Butt welding refers to setting the edges of two structural parts relatively close to each other and welding the edges of the two structural parts relatively close to each other.

[0193] The folded portion 33 is connected to the first connecting piece 31 by butt welding, which is convenient for connection.

[0194] Please refer to Figures 15 and 16. Figure 15 is a schematic cross-sectional view of the current collecting tray 30 provided in some embodiments of the present application. Figure 16 is a schematic cross-sectional view of the current collecting tray 30 provided in other embodiments of the present application.

[0195] In some embodiments, the folding portion 33 is provided with a first thinning area 331 , and the first connecting piece 31 is provided with a second thinning area 311 , and the first thinning area 331 is connected to the second thinning area 311 in a stacked manner.

[0196] The first thinned area 331 refers to a portion of the folded portion 33 close to the first connecting piece 31 , and the thickness of the portion is smaller than the thickness of other portions of the folded portion 33 .

[0197] The second thinned area 311 refers to a partial area of ​​the first connecting piece 31 close to the folded portion 33 , and the thickness of the partial area is smaller than the thickness of other parts of the first connecting piece 31 .

[0198] The first thinning area 331 and the second thinning area 311 are stacked and connected, which means that the first thinning area 331 and the second thinning area 311 are stacked and fixedly connected.

[0199] A first thinned area 331 is provided on the folded portion 33 , and a second thinned area 311 is provided on the first connecting piece 31 . The first thinned area 331 and the second thinned area 311 are stacked to facilitate connection.

[0200] Referring to FIG. 15 , in some embodiments, the first thinned area 331 is staggered with the adapting portion 322 , and the sum of the thicknesses of the first thinned area 331 and the second thinned area 311 is less than the sum of the thicknesses of the first connecting piece 31 and the main body 321 .

[0201] The first thinned area 331 is staggered from the adapting portion 322 , which means that in the thickness direction of the second connecting piece 32 , the first thinned area 331 does not overlap with the adapting portion 322 .

[0202] The first thinning area 331 is staggered with the adapting portion 322, and the sum of the thicknesses of the first thinning area 331 and the second thinning area 311 is smaller than the sum of the thicknesses of the first connecting piece 31 and the main body 321. This can make the thickness of the collecting plate 30 smaller, thereby reducing the space occupied in the battery cell 200 and thereby improving the energy density of the battery cell 200.

[0203] In some embodiments, an opening 320 is provided on the second connecting piece 32, the first thinning area 331 is located in the opening 320, and the first connecting piece 31 is also located in the opening 320, then the second thinning area 311 of the first connecting piece 31 and the first thinning area 331 of the folding portion 33 are stacked, and both are located in the opening 320, and are staggered with the adapting portion 322.

[0204] 16 , in some embodiments, the first thinned region 331 is at least partially stacked on the second connecting piece 32 , and the sum of the thicknesses of the adapting portion 322 , the first thinned region 331 , and the second thinned region 311 is less than the sum of the thicknesses of the first connecting piece 31 and the main body 321 .

[0205] The first thinned area 331 is at least partially stacked on the second connecting piece 32 , which means that the first thinned area 331 is partially stacked on the adapting portion 322 of the second connecting piece 32 , or the first thinned area 331 is completely stacked on the adapting portion 322 .

[0206] The first thinning area 331 is at least partially stacked on the second connecting piece 32, and the sum of the thicknesses of the adapting portion 322, the first thinning area 331 and the second thinning area 311 is smaller than the sum of the thicknesses of the first connecting piece 31 and the main body 321. This can make the overall maximum thickness of the collecting plate 30 smaller, thereby reducing the space occupied in the battery cell 200 and thereby improving the energy density of the battery cell 200.

[0207] In some embodiments, an opening 320 is provided on the second connecting piece 32, and the first thinning area 331 is located on the side. The second thinning area 311 of the first connecting piece 31 is overlapped with the first thinning area 331 of the folding portion 33, and is at least partially located on the side of the opening 320, so that the first thinning area 331 is at least partially overlapped with the second connecting piece 32.

[0208] Referring to FIG. 15 , in some embodiments, the first thinned region 331 is connected to the second thinned region 311 by riveting.

[0209] Riveting refers to the use of rivet columns to connect two structural members. Rivet columns are cylindrical components that can be plastically deformed, such as copper columns or steel columns. As shown in Figure 15, a first hole 332 is provided in the first thinning area 331, and a second hole 312 is provided in the second thinning area 311. A first rivet column 35 is inserted into the first hole 332 and the second hole 312, and the first rivet column 35 is compressed and deformed so that the circumference of the first rivet column 35 abuts against the inner wall of the first hole 332 and the inner wall of the second hole 312, thereby fixedly connecting the first thinning area 331 and the second thinning area 311.

[0210] The first thinned area 331 is connected to the second thinned area 311 by riveting, so that the first thinned area 331 and the second thinned area 311 are more firmly connected.

[0211] In some embodiments, the inner diameter of one end of the first hole 332 close to the second thinning area 311 can be set to be smaller than the inner diameter of the other end. In this way, when the first rivet column 35 is deformed and the peripheral side of the first rivet column 35 is pressed against the inner wall of the first hole 332, the first thinning area 331 can be better fixed, thereby improving the structural strength of the riveting.

[0212] In some embodiments, the first hole position 332 is gradually expanded from the second thinning area 311 to the first thinning area 331 so that the inner diameter of one end of the first hole position 332 close to the second thinning area 311 is smaller than the inner diameter of the other end. This structure is convenient for processing and manufacturing.

[0213] In some embodiments, the first hole position 332 is arranged in a stepped shape, and the inner diameter of one end of the first hole position 332 close to the second thinning area 311 is set smaller than the inner diameter of the other end, so that when the peripheral side of the first rivet column 35 abuts against the inner wall of the first hole position 332, it abuts against the step of the stepped first hole position 332, thereby stably fixing the first thinning area 331 and improving the structural strength of the riveting.

[0214] In some embodiments, the first hole 332 may be a straight hole, which refers to a hole structure with a constant inner diameter. The first rivet post 35 is deformed so that the periphery of the first rivet post 35 abuts against the inner wall of the first hole 332 to achieve an interference fit, thereby securing the first thinned area 331.

[0215] In some embodiments, the inner diameter of one end of the second hole 312 close to the first thinning area 331 can be set to be smaller than the inner diameter of the other end. In this way, when the first rivet column 35 is deformed and the peripheral side of the first rivet column 35 is pressed against the inner wall of the second hole 312, the second thinning area 311 can be better fixed, thereby improving the structural strength of the riveting.

[0216] In some embodiments, the second hole position 312 is gradually expanded from the first thinning area 331 to the second thinning area 311, so that the inner diameter of one end of the second hole position 312 close to the first thinning area 331 is smaller than the inner diameter of the other end. This structure is convenient for processing and manufacturing.

[0217] In some embodiments, the second hole position 312 is arranged in a stepped shape, and the inner diameter of one end of the second hole position 312 close to the first thinning area 331 is set smaller than the inner diameter of the other end, so that when the peripheral side of the first rivet column 35 abuts against the inner wall of the second hole position 312, it abuts against the step of the stepped second hole position 312, thereby stably fixing the second thinning area 311 and improving the structural strength of the riveting.

[0218] In some embodiments, the second hole 312 may also be configured as a straight hole, which refers to a hole structure with a constant inner diameter. The first rivet post 35 is deformed so that the periphery of the first rivet post 35 abuts against the inner wall of the second hole 312 to achieve an interference fit, thereby securing the second thinned area 311.

[0219] In some embodiments, a first rivet post 35 can be provided on the first thinned region 331, that is, the first rivet post 35 and the first thinned region 331 are integrally formed. This allows only the second hole 312 to be provided in the second thinned region 311. The first rivet post 35 is inserted into the second hole 312, and then deformed to abut against the inner wall of the second hole 312, thereby securely connecting the first thinned region 331 to the second thinned region 311.

[0220] In some embodiments, a first rivet post 35 can be provided on the second thinned region 311, that is, the first rivet post 35 and the second thinned region 311 are integrally formed. This allows only the first hole 332 to be provided in the first thinned region 331. The first rivet post 35 is inserted into the first hole 332, and then deformed so that it abuts against the inner wall of the first hole 332, thereby securely connecting the first thinned region 331 to the second thinned region 311.

[0221] Referring to FIG. 16 , in some embodiments, the first thinned region 331 is connected to the second thinned region 311 by penetration welding.

[0222] Penetration welding, also known as penetration welding, involves an arc penetrating the workpieces at the front of the molten pool, forming a small hole. As the heat source moves, a weld bead forms behind the hole. Penetration welding melts through one workpiece and melts at least part of the other, joining the two. Penetration welding can be performed using laser welding or other welding methods, such as argon arc welding.

[0223] The first thinned area 331 is connected to the second thinned area 311 by penetration welding, which is convenient for connection and manufacturing.

[0224] Referring to FIG. 17 , FIG. 18 and FIG. 22 , in some embodiments, the edge of the first connecting piece 31 is butt-welded to the second connecting piece 32 .

[0225] Butt welding refers to setting the edges of two structural parts relatively close to each other and welding the edges of the two structural parts relatively close to each other.

[0226] The edge of the first connecting piece 31 is butt-welded to the second connecting piece 32 to facilitate design and processing.

[0227] Please refer to Figures 17 and 18. In some embodiments, the second connecting piece 32 is provided with an opening 320, the first connecting piece 31 is placed in the opening 320, and the edge of the first connecting piece 31 is butt-welded to the second connecting piece 32 so as to support the first connecting piece 31 in the opening 320 of the second connecting piece 32.

[0228] In some embodiments, the peripheral side of the first connecting piece 31 may be connected to the second connecting piece 32 so that the peripheral side of the first connecting piece 31 is evenly restrained by the second connecting piece 32 , making the first connecting piece 31 smoother.

[0229] In some embodiments, multiple areas on the first connecting piece 31 can be connected to the second connecting piece 32, and these areas are evenly distributed around the first connecting piece 31 so that the restraint force of the second connecting piece 32 on the first connecting piece 31 is more balanced, making the first connecting piece 31 smoother.

[0230] Referring to FIG. 18 to FIG. 20 , in some embodiments, the second connecting piece 32 is provided with an opening 320 , the first connecting piece 31 is placed in the opening 320 , and one side of the first connecting piece 31 is connected to the second connecting piece 32 .

[0231] One side of the first connecting piece 31 is connected to the second connecting piece 32 , which means that a section of the circumference of the first connecting piece 31 is connected to the second connecting piece 32 .

[0232] One side of the first connecting piece 31 is connected to the second connecting piece 32, so that only one side of the first connecting piece 31 is constrained by the second connecting piece 32. When the first connecting piece 31 is welded to the pole tab 211, the first connecting piece 31 can better adapt to twisting and deformation, thereby increasing the fit with the pole tab 211, thereby reducing the press-fitting gap between the first connecting piece 31 and the pole tab 211, thereby reducing the risk of cold welding.

[0233] Please refer to Figures 19 to 21. In some embodiments, a first stacking portion 313 is provided on the edge of the first connecting piece 31, and a second stacking portion 323 is provided on the second connecting piece 32. The first stacking portion 313 and the second stacking portion 323 are stacked and connected, and the sum of the thicknesses of the first stacking portion 313 and the second stacking portion 323 is less than the sum of the thicknesses of the first connecting piece 31 and the second connecting piece 32.

[0234] The first laminated portion 313 is a conductive sheet-like structure connected to the first connecting sheet 31 near the second connecting sheet 32. The thickness of the sheet-like structure is less than that of the first connecting sheet 31. The first laminated portion 313 and the first connecting sheet 31 can be integrally formed. For example, the first laminated portion 313 can be a sheet-like structure extending from the edge of the first connecting sheet 31 toward the second connecting sheet 32. The first laminated portion 313 and the first connecting sheet 31 can also be manufactured separately and then fixedly connected to each other.

[0235] The second stacking portion 323 refers to a portion of the second connecting piece 32 that is adapted to support the first stacking portion 313 , and the thickness of the portion is smaller than the thickness of other portions of the second connecting piece 32 .

[0236] The second stacked portion 323 is stacked and connected to the first stacked portion 313 , which means that the second stacked portion 323 is stacked and arranged on the first stacked portion 313 , and the second stacked portion 323 is fixedly connected to the first stacked portion 313 .

[0237] By making the sum of the thicknesses of the second stacking portion 323 and the first stacking portion 313 smaller than the sum of the thicknesses of the first connecting piece 31 and the main body 321 , the thickness of the collecting plate 30 can be made smaller, thereby reducing the space occupied in the battery cell 200 and thereby improving the energy density of the battery cell 200 .

[0238] By providing a first stacking portion 313 and a second stacking portion 323 and stacking and connecting the first stacking portion 313 and the second stacking portion 323, connection is facilitated; and by making the sum of the thicknesses of the first stacking portion 313 and the second stacking portion 323 smaller than the sum of the thicknesses of the first connecting piece 31 and the second connecting piece 32, the overall maximum thickness of the collecting plate 30 can be made smaller, thereby reducing the space occupied in the battery cell 200 and thereby improving the energy density of the battery cell 200.

[0239] Referring to FIG. 19 , in some embodiments, the first laminate portion 313 and the second laminate portion 323 are connected by penetration welding.

[0240] Penetration welding, also known as penetration welding, involves an arc penetrating the workpieces at the front of the molten pool, forming a small hole. As the heat source moves, a weld bead forms behind the hole. Penetration welding melts through one workpiece and melts at least part of the other, joining the two. Penetration welding can be performed using laser welding or other welding methods, such as argon arc welding.

[0241] The first laminated portion 313 and the second laminated portion 323 are connected by penetration welding, which is convenient for connection and manufacturing.

[0242] 20 and 21 , the first laminate portion 313 and the second laminate portion 323 are connected by riveting.

[0243] Riveting refers to connecting two structural members using rivet columns. Rivet columns refer to columnar components that can be plastically deformed, such as copper columns or steel columns. For example, a first mounting hole 314 can be provided in the first laminated portion 313, and a second mounting hole 324 can be provided in the second laminated portion 323. A second rivet column 36 can be inserted through the first mounting hole 314 and the second mounting hole 324, and the second rivet column 36 can be compressed and deformed so that the circumference of the second rivet column 36 abuts against the inner wall of the first mounting hole 314 and the inner wall of the second mounting hole 324, thereby fixedly connecting the first laminated portion 313 and the second laminated portion 323.

[0244] The mounting hole refers to a hole structure penetrating a structural member. For example, the first mounting hole 314 is a hole structure penetrating the first stacking portion 313 , and the second mounting hole 324 is a hole structure penetrating the second stacking portion 323 .

[0245] The first laminate portion 313 and the second laminate portion 323 are connected by riveting, so that the first laminate portion 313 and the second laminate portion 323 can be more firmly connected.

[0246] In some embodiments, the inner diameter of one end of the first mounting hole 314 close to the second stacked portion 323 can be set to be smaller than the inner diameter of the other end. In this way, when the second rivet column 36 is deformed and the peripheral side of the second rivet column 36 is pressed against the inner wall of the first mounting hole 314, the first stacked portion 313 can be better fixed, thereby improving the structural strength of the riveting.

[0247] In some embodiments, the first mounting hole 314 is gradually enlarged in the direction from the second stacking portion 323 to the first stacking portion 313, so that the inner diameter of one end of the first mounting hole 314 close to the second stacking portion 323 is smaller than the inner diameter of the other end. This structure is convenient for processing and manufacturing.

[0248] In some embodiments, the first mounting hole 314 is arranged in a stepped shape, and the inner diameter of one end of the first mounting hole 314 close to the second stacked portion 323 is set smaller than the inner diameter of the other end, so that when the circumferential side of the second rivet column 36 abuts against the inner wall of the first mounting hole 314, it abuts against the step of the stepped first mounting hole 314, thereby stably fixing the first stacked portion 313 and improving the structural strength of the riveting.

[0249] In some embodiments, the first mounting hole 314 may also be configured as a straight hole, which refers to a hole structure with a constant inner diameter. The second rivet post 36 deforms so that the circumference of the second rivet post 36 abuts against the inner wall of the first mounting hole 314 to achieve an interference fit, thereby securing the first laminated portion 313.

[0250] In some embodiments, the inner diameter of the second mounting hole 324 at one end close to the first stacked portion 313 can be set to be smaller than the inner diameter of the other end. In this way, when the second rivet column 36 is deformed and the peripheral side of the second rivet column 36 is pressed against the inner wall of the second mounting hole 324, the second stacked portion 323 can be better fixed, thereby improving the structural strength of the riveting.

[0251] In some embodiments, the second mounting hole 324 is gradually enlarged in the direction from the first stacking portion 313 to the second stacking portion 323, so that the inner diameter of the second mounting hole 324 at one end close to the first stacking portion 313 is smaller than the inner diameter at the other end. This structure is convenient for processing and manufacturing.

[0252] In some embodiments, the second mounting hole 324 is arranged in a stepped shape, and the inner diameter of one end of the second mounting hole 324 close to the first stacking portion 313 is set smaller than the inner diameter of the other end, so that when the peripheral side of the second rivet column 36 abuts against the inner wall of the second mounting hole 324, it abuts against the step of the stepped second mounting hole 324, thereby stably fixing the second stacking portion 323 and improving the structural strength of the riveting.

[0253] In some embodiments, the second mounting hole 324 may also be a straight hole, which refers to a hole structure with a constant inner diameter. The second rivet post 36 deforms so that the circumference of the second rivet post 36 abuts against the inner wall of the second mounting hole 324 to achieve an interference fit, thereby securing the second laminated portion 323.

[0254] In some embodiments, a second rivet post 36 can be provided on the first laminate portion 313, that is, the second rivet post 36 and the first laminate portion 313 are integrally formed. In this way, the second mounting hole 324 can be provided only on the second laminate portion 323. The second rivet post 36 is inserted into the second mounting hole 324, and then deformed to abut against the inner wall of the second mounting hole 324, thereby securely connecting the first laminate portion 313 and the second laminate portion 323.

[0255] In some embodiments, a second rivet post 36 can be provided on the second laminate portion 323, that is, the second rivet post 36 and the second laminate portion 323 are integrally formed. In this way, the first mounting hole 314 can be provided only on the first laminate portion 313. The second rivet post 36 is inserted into the first mounting hole 314, and then deformed to abut against the inner wall of the first mounting hole 314, thereby securely connecting the first laminate portion 313 and the second laminate portion 323.

[0256] In some embodiments, referring to FIG. 17 to FIG. 20 , the second connecting piece 32 is configured to be circular so that when applied to a cylindrical battery cell 200 , there is no need to rotate the second connecting piece 32 around the central axis of the cylindrical battery cell 200 , thereby facilitating use.

[0257] In some embodiments, referring to FIG. 5 and FIG. 9 to FIG. 11 , the outer contour of the second connecting piece 32 is quasi-circular.

[0258] Quasi-circular means that most of the periphery of the structural part is in the shape of an arc, and these arcs are located on the same circle.

[0259] The outer contour of the second connecting piece 32 is set to be circular, so as to be applied to the cylindrical battery cell 200 .

[0260] In some embodiments, the second connecting piece 32 is provided with an opening 320 , the first connecting piece 31 is embedded in the opening 320 , and the opening 320 is circular.

[0261] The opening 320 on the second connecting piece 32 is configured to be circular, so as to facilitate application in a cylindrical battery cell 200 and also facilitate the design and manufacture of the opening 320 .

[0262] In some embodiments, the second connecting piece 32 is provided with an opening 320 , and the first connecting piece 31 is embedded in the opening 320 . The first connecting piece 31 is quasi-circular.

[0263] The first connecting piece 31 is quasi-circular so that when applied to a cylindrical battery cell 200 , there is no need to rotate the first connecting piece 31 around the central axis of the cylindrical battery cell 200 , thereby facilitating connection between the first connecting piece 31 and the tab 211 .

[0264] Referring to Figures 5, 9 to 14, and 17 to 20, in some embodiments, the second connecting piece 32 is provided with an opening 320, the first connecting piece 31 is embedded in the opening 320, and the first connecting piece 31 is provided with a through hole 310 at the center of the opening 320.

[0265] The through hole 310 refers to a hole structure that penetrates the structural member.

[0266] Since the first connecting piece 31 is embedded in the opening 320 of the second connecting piece 32, the through hole 310 of the first connecting piece 31 actually passes through the entire collecting plate 30. The through hole 310 is formed at the center of the first connecting piece 31 corresponding to the opening 320, and the through hole 310 is also located at the center of the collecting plate 30.

[0267] A through hole 310 is provided on the first connecting piece 31, which can play a positioning role when the first connecting piece 31 is welded to the tab 211, and a pressure relief mechanism is provided on the side of the shell 221 corresponding to the collecting plate 30. When the battery cell 200 expands and releases pressure, the active material in the shell 221 can be easily ejected, thereby reducing the risk of the first connecting piece 31 blocking the pressure relief mechanism and improving the reliability of the battery cell 200.

[0268] The pressure relief mechanism refers to a structural component such as a pressure relief valve or explosion-proof valve on the battery cell 200. When the battery cell 200 expands abnormally, the pressure relief mechanism is used to eject gas or liquid generated in the battery cell 200 to relieve pressure in the battery cell 200.

[0269] In some embodiments, the through hole 310 is circular, oval, or polygonal.

[0270] The through hole 310 is set to be circular, elliptical or polygonal to facilitate design and production; when the through hole 310 is set to be polygonal, and a pressure relief mechanism is set on the side of the shell 221 corresponding to the collecting plate 30, when the battery cell 200 expands and releases pressure, the first connecting piece 31 can be torn from the corners of the through hole 310 to facilitate the ejection of the active material in the shell 221, reducing the risk of the first connecting piece 31 blocking the pressure relief mechanism and improving the reliability of the battery cell 200.

[0271] Referring to Figure 22 , in some embodiments, the first connecting piece 31 and the second connecting piece 32 can be configured in a semicircular shape. The first connecting piece 31 and the second connecting piece 32 are connected to form a circular current collecting tray 30 for use in cylindrical battery cells 200. With this structure, the projection of the first connecting piece 31 and the projection of the second connecting piece 32 overlap in the thickness perpendicular to the second connecting piece 32. This allows the overall thickness of the current collecting tray 30 to be reduced, thereby reducing the space occupied in the battery cell 200 and improving the energy density of the battery cell 200.

[0272] According to some embodiments of the present application, a battery cell 200 is provided, comprising a housing 221, an electrode assembly 21, and a current collecting plate 30. The electrode assembly 21 is mounted in the housing 221, and a tab 211 is provided on the electrode assembly 21. The current collecting plate 30 comprises a first connecting piece 31, a second connecting piece 32, and a folded portion 33. The folded portion 33 and the second connecting piece 32 are integrally formed. The second connecting piece 32 is provided with an opening 320, and the first connecting piece 31 is embedded in the opening 320. The folded portion 33 is stacked on the second connecting piece 32. One side of the folded portion 33 is connected to an edge of the second connecting piece 32, and the other side of the folded portion 33 is connected to the first connecting piece 31. The first connecting piece 31 is welded to the tab 211, and the second connecting piece 32 is welded to the housing 221.

[0273] The current collecting tray 30 is formed by connecting the first connecting tab 31 and the second connecting tab 32. The first connecting tab 31 is welded to the tab 211 of the battery cell 200, and the second connecting tab 32 is welded to the housing 221 of the battery cell 200. This connects the housing 221 and the tab 211, improving the stability and reliability of the connection. By embedding the first connecting tab 31 into the opening 320 of the second connecting tab 32, the thickness of the current collecting tray 30 can be reduced, thereby reducing the space occupied within the battery cell 200 and increasing the energy density of the battery cell 200. The folding portion 33 and the second connecting piece 32 are integrally formed to facilitate connection between the folding portion 33 and the second connecting piece 32, and are also easy to process and manufacture. For example, the sheet plate of the material for making the first connecting piece 31 can be connected to the sheet plate of the material for making the second connecting piece 32. That is, after the above-mentioned first plate 301 and the second plate 302 are connected, the first connecting piece 31, the folding portion 33 and the second connecting piece 32 are punched out, and then folded so that the first connecting piece 31 is embedded in the opening 320 of the second connecting piece 32, and the collecting plate 30 is obtained. It is easy to manufacture and convenient for batch production.

[0274] According to some embodiments of the present application, the present application also provides a battery, comprising the battery cell described in any of the above solutions.

[0275] According to some embodiments of the present application, the present application also provides an electrical device, comprising the battery described in any of the above solutions.

[0276] The power-consuming device may be any of the aforementioned devices or systems using batteries.

[0277] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: case; An electrode assembly is installed in the housing, and a pole ear is provided on the electrode assembly; The current collecting plate comprises a first connecting piece and a second connecting piece, wherein the first connecting piece is connected to the second connecting piece, the first connecting piece is connected to the pole tab by welding, and the second connecting piece is connected to the shell by welding; Along a direction perpendicular to the thickness of the second connecting sheet, a projection of the first connecting sheet at least partially overlaps with a projection of the second connecting sheet.

2. The battery cell according to claim 1, characterized in that: The second connecting piece is provided with an opening, and the first connecting piece is embedded in the opening.

3. The battery cell according to claim 2, characterized in that: One side of the first connecting piece is connected to the second connecting piece.

4. The battery cell according to any one of claims 1 to 3, characterized in that: The current collecting plate further includes a folded portion, which is stacked on the second connecting piece, one side of the folded portion is connected to an edge of the second connecting piece, and the other side of the folded portion is connected to the first connecting piece.

5. The battery cell according to claim 4, characterized in that: The second connecting piece includes a main body portion and an adapting portion, wherein the adapting portion is connected to the main body portion, the adapting portion is laminated with the folding portion, and the thickness of the adapting portion is smaller than the thickness of the main body portion.

6. The battery cell according to claim 5, characterized in that: The sum of the thicknesses of the folded portion and the adapting portion is smaller than the sum of the thicknesses of the first connecting piece and the main body portion.

7. The battery cell according to any one of claims 4 to 6, characterized in that: The folding portion and the second connecting piece are an integrally formed structure.

8. The battery cell according to claim 7, characterized in that: A fold is provided at a connection between the folded portion and the second connecting piece.

9. The battery cell according to any one of claims 4 to 8, characterized in that: The folded portion is provided with a first thinned area, the first connecting sheet is provided with a second thinned area, and the first thinned area is connected to the second thinned area in a stacked manner; The first thinning zone is staggered with the adapter portion, and the sum of the thicknesses of the first thinning zone and the second thinning zone is less than the sum of the thicknesses of the first connecting piece and the main body; or, the first thinning zone is at least partially stacked on the adapter portion, and the sum of the thicknesses of the adapter portion, the first thinning zone and the second thinning zone is less than the sum of the thicknesses of the first connecting piece and the main body.

10. The battery cell according to claim 9, characterized in that: The first thinned area is connected to the second thinned area by penetration welding, or the first thinned area is connected to the second thinned area by riveting.

11. The battery cell according to any one of claims 1 to 3, characterized in that: The edge of the first connecting piece is connected to the second connecting piece by butt welding.

12. The battery cell according to any one of claims 1 to 3, characterized in that: A first laminated portion is provided at the edge of the first connecting sheet, a second laminated portion is provided on the second connecting sheet, the first laminated portion and the second laminated portion are laminated and connected, and the sum of the thicknesses of the first laminated portion and the second laminated portion is less than the sum of the thicknesses of the first connecting sheet and the second connecting sheet.

13. The battery cell according to claim 12, characterized in that: The first laminated portion is connected to the second laminated portion by penetration welding, or the first laminated portion is connected to the second laminated portion by riveting.

14. The battery cell according to any one of claims 2 to 13, characterized in that: The outer contour of the second connecting piece is circular.

15. The battery cell according to any one of claims 2 to 14, characterized in that: The opening is circular.

16. The battery cell according to claim 15, characterized in that: The first connecting piece is circular in shape.

17. The battery cell according to claim 15 or 16, characterized in that: The first connecting sheet is provided with a through hole at the center of the opening.

18. The battery cell according to claim 17, characterized in that: The through hole is circular, elliptical or polygonal.

19. A battery, characterized in that: Comprising a battery cell as claimed in any one of claims 1 to 18.

20. An electrical device, characterized in that: Comprising the battery of claim 19.

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