Battery monomer, battery device, power utilization device and energy storage device

Abstract

The utility model discloses a battery monomer, a battery device, a power utilization device and an energy storage device. A battery cell includes a housing, at least one electrode assembly, an electrode terminal, and an electrical connector. A containing cavity is formed in the shell, the shell comprises a first wall, and a mounting hole is formed in the first wall. The at least one electrode assembly is located in the containing cavity, and the electrode assembly comprises an electrode main body and a tab connected with the electrode main body. The electrode terminals are arranged in the mounting holes in a penetrating mode. The electrical connector connects the electrode terminal and the tab. Wherein the tabs comprise welding parts, under the condition that the number of the tabs with the same polarity is multiple, the welding parts of the tabs with the same polarity are at least partially overlapped to form an overlapping part, and the overlapping part is welded with the electric connecting piece to form a welding mark. The thickness of the battery cell is small, and the energy density of the battery cell is not affected. Moreover, the number of welding times in the production and manufacturing process of the single battery is small, so that the production cost is reduced, and the production efficiency and the production takt are improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to battery cells, battery devices, power-consuming devices, and energy storage devices. Background Art

[0002] New energy batteries are being used more and more widely in life and industry. For example, new energy vehicles equipped with battery devices have been widely used. In addition, battery devices are also increasingly being used in energy storage fields.

[0003] With the continuous development of battery technology, how to reduce the size of battery cells and improve the production efficiency of battery cells is one of the research topics in the industry. Utility Model Content

[0004] In order to solve the above technical problems, the present application provides a battery cell, a battery device, an electrical device and an energy storage device with a small size, low production cost and high production efficiency.

[0005] This application is implemented through the following technical solutions.

[0006] The first aspect of the present application provides a battery cell, which includes: a shell with a accommodating cavity formed therein, the shell including a first wall, the first wall having a mounting hole formed therein; at least one electrode assembly located in the accommodating cavity, the electrode assembly including an electrode body and a tab connected to the electrode body; an electrode terminal passing through the mounting hole; and an electrical connector connecting the electrode terminal and the tab; wherein the tab includes a welding portion, and when there are multiple tabs with the same polarity, the welding portions of the tabs with the same polarity at least partially overlap to form an overlapping portion, and the overlapping portion is welded to the electrical connector to form a weld mark.

[0007] The tabs of the battery cells of the present application with the same polarity at least partially overlap to form an overlapping portion, and are welded to the electrical connector at the overlapping portion. Thus, only one welding operation is required to achieve the connection between the tabs and the electrical connector, which can reduce the number of welding times, thereby helping to improve production efficiency and reduce production costs.

[0008] In addition, since only one weld mark is formed after welding multiple pole tabs with the same polarity to the electrical connector, the space occupied by multiple weld marks can be saved compared to the situation where multiple pole tabs are welded separately to form multiple weld marks, thereby reducing the size of the electrical connector, and further effectively reducing the size of the battery cell, so that the battery cell can be better used in an installation environment with relatively limited space and will not affect the energy density of the battery cell.

[0009] In some embodiments, the thickness direction of the electrode body is a first direction; along the first direction, the width of the overlapping portion is greater than the width of the weld mark.

[0010] As a result, the weld marks can be completely located in the overlapping area of the tabs, thereby increasing the connection area between the tabs, further improving welding reliability, reducing the possibility of adverse situations such as poor welding or welding failure between the tabs, and improving welding quality.

[0011] In some embodiments, the weld mark is located in a central area of the overlapping portion.

[0012] This further improves the welding reliability between tabs of the same polarity, ensuring sufficient welding of multiple tabs that overlap at the overlapped portion. Furthermore, the weld mark is located in the center of the overlapped portion, ensuring that the tabs on opposite sides along the first direction extend to the same length, reducing the possibility of excessive stretching on one side and improving the reliability of the battery cell.

[0013] In some embodiments, the electrical connector includes a tab connection portion, an electrode terminal connection portion and an intermediate connection portion, the tab connection portion connects the tab, the electrode terminal connection portion connects the electrode terminal, and the intermediate connection portion connects the tab connection portion and the electrode terminal connection portion; the electrode terminal connection portion and the tab connection portion extend along a second direction, the intermediate connection portion extends along a third direction, and the tab connection portion is closer to the first wall than the electrode terminal connection portion in the third direction; the welding portion of the tab is welded to the side of the tab connection portion facing away from the first wall; the first direction, the second direction and the third direction are perpendicular to each other.

[0014] As a result, the tab connection portion and the electrode terminal connection portion have a certain height difference along the third direction, so that the overlapping portion of the tab can be located in the space generated by the height difference between the tab connection portion and the electrode terminal connection portion, so that the overlapping portion will not occupy too much space in the accommodating cavity of the shell, and the tab can be overlapped and welded with the electrical connector without affecting the energy density of the battery cell.

[0015] In some embodiments, the battery cell further includes an insulating member, which is located on the side of the first wall facing the electrode assembly; each of the pole tabs further includes a bending portion, which is connected to the welding portion, and the bending portion protrudes relative to the welding portion in the third direction toward the side of the first wall; along the first direction, the width of the pole tab connection portion is less than a first dimension; wherein the first dimension is the width of the insulating member along the first direction minus the width of the bending portion of each of the pole tabs connected to the pole tab connection portion along the first direction.

[0016] Since the tab needs to be bent when connected to the tab connecting portion, when the size of the tab connecting portion is smaller than the first size, there is enough space in the shell to accommodate the bent portion of the tab, thereby meeting the process requirements of the tab bending and improving the connection reliability between the tab and the electrical connector.

[0017] In some embodiments, the first dimension is the width of the insulating member along the first direction minus 6 mm.

[0018] Therefore, most of the tab folding process requirements can be met, so that there is a sufficient distance between the insulating member and the tab connecting portion to accommodate the bending portion of most tabs.

[0019] In some embodiments, along the first direction, the width of the tab connection portion is greater than the width of the weld mark.

[0020] As a result, the tab connection portion can have enough space for welding the overlapping portion of the tab, thereby improving the welding reliability between the tab and the electrical connector.

[0021] In some embodiments, along the third direction, the height of the intermediate connecting portion is the distance between the bottom end surface of the electrode terminal and the insulating member minus the distance between the tab connecting portion and the insulating member.

[0022] In this way, while ensuring the installation accuracy of the electrical connector, a height difference can be formed between the pole tab connection part of the electrical connector and the electrode terminal connection part along the third direction, so that the overlapping part of the pole tab can be located in the space formed by the height difference, so that the overlapping part does not occupy too much space in the shell, and the pole tab can be welded to the electrical connector through a weld mark, thereby reducing the thickness of the battery cell without affecting the energy density of the battery cell, reducing the number of welding times, and reducing production costs.

[0023] In some embodiments, at least one side of the tab connecting portion along the first direction has an accommodation space, and the bent portion is accommodated in the accommodation space.

[0024] In this way, the accommodating space on the side of the electrical connector along the first direction can be fully utilized, and the space occupied by the tab in the height direction (third direction) can be reduced, so that the tab is not located entirely below the electrical connector, which is beneficial to improving the space utilization rate inside the shell of the battery cell and reserving more space for the electrode body. As a result, the volume of the electrode body can be appropriately increased without changing the shell size of the battery cell, thereby improving the energy density of the battery cell.

[0025] In some embodiments, along the first direction, the width of the bent portion is smaller than the distance between the insulating member and the tab connecting portion.

[0026] In this way, the bent portion of the tab can be accommodated in the accommodation space while ensuring a good appearance of the tab, thereby saving the space occupied by the tab in the accommodation cavity along the third direction.

[0027] In some embodiments, the tab connection portion is flat; and / or the electrode terminal connection portion is flat.

[0028] This is more conducive to connecting the electrode terminal and the tab to the electrode terminal connecting portion and the tab connecting portion respectively, thereby improving the connection reliability and making the electrical connector more stable.

[0029] In some embodiments, the electrode terminal includes a positive terminal and a negative terminal; the electrical connector includes a first electrical connector and a second electrical connector; the tabs include multiple positive tabs and multiple negative tabs, each of the positive tabs is located on the same side as the positive terminal, and / or each of the negative tabs is located on the same side as the negative terminal, each of the positive tabs is connected to the positive terminal through the first electrical connector, and each of the negative tabs is connected to the negative terminal through the second electrical connector.

[0030] Thus, the positive electrode tabs at least partially overlap to form an overlapping portion, which is then welded to the first electrical connector. The negative electrode tabs at least partially overlap to form an overlapping portion, which is then welded to the second electrical connector. Thus, each of the positive and negative electrode tabs only requires a single weld to connect to the first and second electrical connectors, reducing the number of welds, thereby improving production efficiency, and reducing production costs. Furthermore, since each of the positive and negative electrode tabs only forms a single weld mark after being welded to the first and second electrical connectors, this helps reduce the thickness of the battery cell, allowing the battery cell to be better suited for installation in environments with limited space.

[0031] In addition, since the positive electrode tab and the positive terminal are located at the same end, and / or the negative electrode tab and the negative terminal are located at the same end, it is easier to connect the tabs and the electrode terminals, and can save space in the battery cell shell, which is beneficial to improving the energy density of the battery cell.

[0032] In some embodiments, the electrode terminal includes a positive terminal and a negative terminal; the electrical connector includes a first electrical connector and a second electrical connector; the tabs include multiple positive tabs and multiple negative tabs, each of the positive tabs is located on a different side from the positive terminal, and / or each of the negative tabs is located on a different side from the negative terminal, each of the positive tabs is connected to the positive terminal through the first electrical connector, and each of the negative tabs is connected to the negative terminal through the second electrical connector.

[0033] Thus, the positive electrode tabs at least partially overlap to form an overlapping portion, which is then welded to the first electrical connector. The negative electrode tabs at least partially overlap to form an overlapping portion, which is then welded to the second electrical connector. Thus, each of the positive and negative electrode tabs only requires a single weld to connect to the first and second electrical connectors, reducing the number of welds, thereby improving production efficiency, and reducing production costs. Furthermore, since each of the positive and negative electrode tabs only forms a single weld mark after being welded to the first and second electrical connectors, this helps reduce the thickness of the battery cell, allowing the battery cell to be better suited for installation in environments with limited space.

[0034] In addition, since the positive electrode tab and the positive terminal are located on different sides, and / or the negative electrode tab and the negative terminal are located on different sides, this helps to improve the flexibility of connecting the tab and the electrode terminal, and when multiple battery cells are grouped, it helps to improve the connection flexibility between battery cells.

[0035] In some embodiments, there are multiple electrode assemblies, and the multiple electrode assemblies are arranged in parallel along the first direction. The welding parts of the electrode tabs with the same polarity of each electrode assembly are connected through the same electrical connector.

[0036] This can reduce the number of assembly steps, lower the difficulty of assembly, and help reduce production costs.

[0037] A second aspect of the present application provides a battery device, comprising: a box; and at least one battery cell according to the first aspect of the present application, wherein the battery cell is accommodated in the box.

[0038] The battery device provided by this application, because it includes the thinner battery cells provided by the first aspect above, can effectively reduce the size of the battery device, allowing the battery device to be installed in installation environments with limited size, while also reducing production costs and increasing production efficiency. Furthermore, without changing the size of the battery device housing, the housing can accommodate more battery cells, which helps to increase the energy density of the battery device.

[0039] A third aspect of the present application provides an electrical device, which includes the battery cell described in the first aspect of the present application or the battery device described in the second aspect of the present application for providing electrical energy.

[0040] The electrical device of the embodiment of the present application includes the smaller battery cells provided by the first aspect or the smaller battery device provided by the second aspect. Therefore, more battery cells or battery devices can be arranged in the electrical device, which is beneficial to extending the power supply time of the battery cells or battery devices to the electrical device, and can also provide good power supply to the electrical device when the space of the electrical device is limited.

[0041] A fourth aspect of the present application provides an energy storage device, which includes the battery cell described in the first aspect of the present application or the battery device described in the second aspect of the present application for providing electrical energy.

[0042] The energy storage device of the embodiment of the present application includes the smaller battery cells provided by the first aspect or the smaller battery device provided by the second aspect. Therefore, more battery cells or battery devices can be arranged in the energy storage device, which is beneficial to extending the power supply time of the battery cells or battery devices to the energy storage device. In addition, even when the space of the energy storage device is limited, it can provide good power supply to the energy storage device.

[0043] Utility model effect

[0044] Through the present application, the size of the battery cell along the thickness direction can be reduced, and the number of welding times can be reduced, the production cost can be reduced, and the production efficiency can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to denote the same components. In the drawings:

[0046] Figure 1 A schematic structural diagram of a vehicle provided for some embodiments of the present application;

[0047] Figure 2 A schematic exploded perspective view of a battery device provided in some embodiments of the present application;

[0048] Figure 3 A schematic exploded perspective view of a battery cell provided in some embodiments of the present application;

[0049] Figure 4 A schematic diagram of a partial planar structure of a positive electrode sheet, a negative electrode sheet, and a separator of an electrode body provided in some embodiments of the present application;

[0050] Figure 5 A schematic diagram of the planar structure of a battery cell provided in some embodiments of the present application;

[0051] Figure 6 for Figure 5 Enlarged view of the circled section A;

[0052] Figure 7 A schematic diagram of the three-dimensional structure of an electrical connector provided in some embodiments of the present application;

[0053] Figure 8 A schematic cross-sectional view of a battery cell provided for some embodiments of the present application;

[0054] Figure 9 for Figure 8 Enlarged view of the circled section B;

[0055] Figure 10 A partial schematic diagram of a tab connected to an electrical connector according to some embodiments of the present application, wherein an electrode body is shown;

[0056] Figure 11 A partial schematic diagram of a tab connected to an electrical connector according to some embodiments of the present application, wherein two electrode bodies are shown;

[0057] Figure 12 A partial schematic diagram of the connection between the electrode tab and the electrical connector provided in some embodiments of the present application, wherein four electrode bodies are shown;

[0058] Figure 13 A partial schematic cross-sectional view from another perspective of a battery cell provided for some embodiments of the present application.

[0059] Description of Reference Numerals

[0060] 1-shell; 1a-accommodation cavity; 11-first wall; 12-sealing bag; 2-electrode assembly; 21-electrode body; 211-positive electrode sheet; 212-negative electrode sheet; 213-isolator; 22-ear; 221-welding portion; 2211-overlapping portion; 222-bending portion; 223-positive electrode ear; 224-negative electrode ear; 3-electrode terminal; 31-positive terminal; 32-negative terminal; 4-electrical connector; 41-ear connector; 42-electrode terminal connector; 43-middle connector; 44-first electrical connector; 45-second electrical connector; 5-weld stamp; 6-insulating member; 10-accommodation space; 100-battery cell; 200-controller; 300-motor; 400-battery device; 401-casing; 401a-cover; 401b-bottom plate; 1000-vehicle. DETAILED DESCRIPTION

[0061] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0062] 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 for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "including" and "having" and any variations thereof in this application are intended to cover non-exclusive inclusions.

[0063] In the description of the embodiments of this application, the technical terms "first," "second," "third," etc. are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise specifically defined.

[0064] 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.

[0065] 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.

[0066] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", and "circumferential" are 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 device or element referred to must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be understood as limitations on the embodiments of the present application.

[0067] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connect," 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; 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.

[0068] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the technical term "contact" should be understood in a broad sense, and can be direct contact, contact through an intermediate medium layer, contact with essentially no interaction force between the two contacting parties, or contact with interaction force between the two contacting parties.

[0069] Below, this application is described in detail.

[0070] Currently, new energy batteries are increasingly being used in everyday life and industry. They are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in a variety of fields such as aerospace. As the application of power batteries continues to expand, market demand is also growing.

[0071] During the manufacturing process of battery cells, it is necessary to electrically connect the tabs of the electrode assembly in the battery cell to the electrode terminals provided on the shell through electrical connectors (e.g., adapters) so that current can be drawn from or introduced into the electrode assembly.

[0072] In related art, when a battery cell contains multiple tabs of the same polarity, each tab is individually welded to the electrical connector, resulting in multiple weld marks on the electrical connector. The size of the electrical connector is limited by the size and number of weld marks. Specifically, to meet welding process requirements, the width (dimension along the first direction) of the electrical connector may be larger, which in turn may result in a larger thickness (dimension along the first direction) of the battery cell.

[0073] As technology advances, devices are becoming increasingly integrated and miniaturized. Consequently, thinner battery cells are finding more and more applications. For example, in some installation spaces where installation space is extremely limited, thicker battery cells are clearly not suitable. To reduce the size of a battery cell, the number of electrode assemblies within the cell or the size of the electrode body may be reduced, which inevitably impacts the energy density of the cell.

[0074] In response to the problems existing in the above-mentioned related technologies, the present application proposes a battery cell, which includes a shell, at least one electrode assembly, an electrode terminal and an electrical connector. A accommodating cavity is formed inside the shell, and the shell includes a first wall, and the first wall is formed with a mounting hole. At least one electrode assembly is located in the accommodating cavity, and the electrode assembly includes an electrode body and a tab connected to the electrode body. The electrode terminal is passed through the mounting hole. The electrical connector connects the electrode terminal and the tab. The tab includes a welding portion. When there are multiple tabs with the same polarity, the welding portions of the tabs with the same polarity at least partially overlap to form an overlapping portion, and the overlapping portion is welded to the electrical connector to form a weld mark.

[0075] Since only one weld mark is formed after welding multiple tabs with the same polarity to the electrical connector, compared with the situation where multiple tabs are welded separately to form multiple weld marks, the space occupied by multiple weld marks can be saved, thereby reducing the size of the electrical connector, and then effectively reducing the size of the battery cell, so that the battery cell can be better used in an installation environment with relatively limited space, and will not affect the energy density of the battery cell.

[0076] In addition, the tabs of the battery cells of the present application with the same polarity at least partially overlap to form an overlapping portion, and are welded to the electrical connector at the overlapping portion. Thus, only one welding operation is required to achieve the connection between the tabs and the electrical connector, which can reduce the number of welding times, thereby helping to improve production efficiency and reduce production costs.

[0077] The battery cells provided in the embodiments of the present application can be used, but are not limited to, in energy storage power supply systems, electrical devices such as vehicles, ships or aircraft, as well as energy storage devices such as energy storage containers and energy storage cabinets.

[0078] The embodiments of the present application provide an electrical device including the above-mentioned battery cell for providing electrical energy, and the electrical device includes but is not limited to a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0079] In the following embodiments, for the convenience of description, the electric device of one embodiment of the present application is taken as an example of a vehicle 1000. The following description is made with reference to the accompanying drawings.

[0080] Figure 1 The schematic diagram of the structure of the vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended range vehicle. Figure 1 As shown, battery cells 100 are installed inside vehicle 1000. Battery cells 100 can be located at the bottom, front, or rear of vehicle 1000. Battery cells 100 can be used to power vehicle 1000. For example, battery cells 100 can serve as an operating power source for vehicle 1000. Vehicle 1000 also includes a controller 200 and a motor 300. Controller 200 is used to control battery cells 100 to power motor 300, for example, to meet the power requirements of vehicle 1000 during startup, navigation, and driving.

[0081] In some embodiments of the present application, the battery cell 100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0082] Figure 2 This is a schematic diagram of a three-dimensional exploded view of a battery device 400 provided in an embodiment of the present application. Figure 2 As shown, the battery device 400 includes a box body 401 and at least one battery cell 100. The box body 401 includes a cover 401a and a bottom plate 401b. The cover 401a covers the bottom plate 401b, thereby forming a storage area for the battery cell 100 between the bottom plate 401b and the cover 401a.

[0083] In the battery device 400, there can be multiple battery cells 100, and the multiple battery cells 100 can be connected in series, in parallel, or in a mixed connection. Mixed connection means that the multiple battery cells 100 are both connected in series and in parallel. The multiple battery cells 100 can be directly connected in series, in parallel, or in a mixed connection, and then the whole composed of the multiple battery cells 100 is placed in the storage space formed by the bottom plate 401b and the cover 401a. Of course, the battery cells 100 can also be a battery module formed by first connecting multiple battery cells 100 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and are accommodated in the storage space formed by the bottom plate 401b and the cover 401a. The battery device 400 can also include other structures. For example, the battery device 400 can also include a busbar component for realizing electrical connection between the multiple battery cells 100.

[0084] Below, refer to Figures 3 to 13 Some embodiments of the present application are described in detail.

[0085] Figure 3 A schematic exploded perspective view of a battery cell provided in some embodiments of the present application. Figure 4 A schematic diagram of the partial planar structure of the positive electrode sheet, negative electrode sheet and separator of the electrode body provided in some embodiments of the present application. Figure 5 A schematic diagram of the planar structure of a battery cell provided in some embodiments of the present application. Figure 6 for Figure 5 Enlarged view of the circled section A. Figure 7 A schematic diagram of the three-dimensional structure of an electrical connector provided in some embodiments of the present application. Figure 8 Schematic cross-sectional view of a battery cell provided for some embodiments of the present application. Figure 9 for Figure 8 Magnified view of the circled part B. Figure 10 A partial schematic diagram of the connection between the electrode tab and the electrical connector provided in some embodiments of the present application, wherein the situation of an electrode body is shown. Figure 11 A partial schematic diagram of the connection between the electrode tab and the electrical connector provided in some embodiments of the present application, wherein two electrode bodies are shown. Figure 12 A partial schematic diagram of the connection between the electrode tab and the electrical connector provided in some embodiments of the present application, wherein four electrode bodies are shown. Figure 13 A partial schematic cross-sectional view from another perspective of a battery cell provided for some embodiments of the present application.

[0086] In some embodiments of the present application, for ease of description, a first direction, a second direction, and a third direction are set, and the first direction, the second direction, and the third direction are perpendicular to each other. However, those skilled in the art should understand that the embodiments of the present application are not limited to the case where the three directions are perpendicular to each other. Figures 3 to 11 As shown by the arrows in FIG, the direction of arrow X is the first direction, the direction of arrow Y is the second direction, and the direction of arrow Z is the third direction. The direction indicated by arrow Z along the third direction is sometimes referred to as "upward," and the opposite direction is referred to as "downward."

[0087] The first aspect of the present application provides a battery cell 100, which includes a shell 1, at least one electrode assembly 2, an electrode terminal 3 and an electrical connector 4. A accommodating cavity 1a is formed inside the shell 1, and the shell 1 includes a first wall 11, and the first wall 11 is formed with a mounting hole. At least one electrode assembly 2 is located in the accommodating cavity 1a, and the electrode assembly 2 includes an electrode body 21 and a tab 22 connected to the electrode body 21. The electrode terminal 3 is passed through the mounting hole. The electrical connector 4 connects the electrode terminal 3 and the tab 22. Among them, the tab 22 includes a welding portion 221. When there are multiple tabs 22 with the same polarity, the welding portions 221 of the tabs 22 with the same polarity at least partially overlap to form an overlapping portion 2211, and the overlapping portion 2211 is welded to the electrical connector 4 to form a weld mark 5.

[0088] The battery cell 100 refers to a basic unit that can realize mutual conversion between chemical energy and electrical energy, and can be used to manufacture a battery device 400 to supply power to an electrical device or an energy storage device.

[0089] In the embodiment of the present application, the battery cell 100 is a secondary battery cell. A secondary battery cell refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0090] The battery cell 100 can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-hydrogen battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc., and the embodiments of the present application are not limited to this.

[0091] In the embodiment of the present application, the battery cell 100 is a square-shell battery cell. In some other embodiments, the battery cell 100 may also be a battery cell of other shapes, which is not particularly limited in the present application.

[0092] like Figure 3 As shown, the battery cell 100 includes a housing 1, which is the outer protective shell of the battery cell 100 and defines a receiving cavity 1a therein for accommodating the electrode assembly 2 and electrolyte. The housing 1 may be made of steel, aluminum, plastic (e.g., polypropylene), composite metal (e.g., copper-aluminum composite), or aluminum-plastic film.

[0093] In some embodiments, the housing 1 can be a sealed structure or a non-sealed structure. For example, when the housing 1 is a sealed structure, it protects the electrode assembly 2 contained therein. A sealing bag 12 can also be included between the housing 1 and the electrode assembly 2. The sealing bag 12 is used to encapsulate the electrode assembly 2 and the electrolyte. Specifically, the sealing bag 12 can be a bag-shaped insulating member or an aluminum-plastic film.

[0094] The electrode assembly 2 is a component where electrochemical reactions occur in the battery cell 100, and the electrode assembly 2 includes an electrode body 21. Figure 4 As shown, the electrode body 21 includes a positive electrode sheet 211, a negative electrode sheet 212, and a separator 213. The positive electrode sheet 211, the negative electrode sheet 212, and the separator 213 are generally stacked along the thickness direction (first direction) of the battery cell. During the charge and discharge process of the battery cell 100, active ions (such as lithium ions) are embedded and released back and forth between the positive electrode sheet 211 and the negative electrode sheet 212. The separator 213 is arranged between the positive electrode sheet 211 and the negative electrode sheet 212 to prevent the positive and negative electrode sheets from short-circuiting while allowing active ions to pass through.

[0095] In some embodiments, the positive electrode sheet 211 may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0096] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is provided on either or both of the two facing surfaces of the positive electrode current collector.

[0097] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum or stainless steel with a silver surface treatment, stainless steel, copper, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0098] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.

[0099] In some embodiments, the positive electrode sheet 211 may be made of metal foam. The metal foam may be nickel foam, copper foam, aluminum foam, or alloy foam. When the metal foam is used as the positive electrode, the surface of the metal foam may or may not be provided with a positive electrode active material. As an example, a lithium source material, potassium metal, or sodium metal may be filled and / or deposited within the metal foam, where the lithium source material is lithium metal and / or a lithium-rich material.

[0100] In some embodiments, the negative electrode sheet 212 may include a negative current collector.

[0101] As an example, the negative electrode current collector may be a metal foil, a metal foam, or a composite current collector. For example, as the metal foil, aluminum or stainless steel with a silver surface treatment, stainless steel, copper, nickel, carbon, or titanium, etc., may be used. The composite current collector may include a polymer material base layer and a metal layer. The metal foam may be nickel foam, copper foam, aluminum foam, or alloy foam, etc. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.). In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0102] In some embodiments, the separator 213 is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0103] As an example, the main material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics.

[0104] In some embodiments, separator 213 is a solid electrolyte.

[0105] In some embodiments, the electrode body 21 is a wound structure in which the positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0106] In some embodiments, the electrode body 21 is a laminated structure.

[0107] As an example, a plurality of positive electrode sheets 211 and a plurality of negative electrode sheets 212 may be provided, and the plurality of positive electrode sheets 211 and the plurality of negative electrode sheets 212 may be alternately stacked.

[0108] As an example, a plurality of positive electrode sheets 211 may be provided, and the negative electrode sheet 212 may be folded to form a plurality of stacked folded segments, with one positive electrode sheet 211 being sandwiched between adjacent folded segments.

[0109] As an example, the positive electrode sheet 211 and the negative electrode sheet 212 are both folded to form a plurality of stacked folded segments.

[0110] As an example, a plurality of separators 213 may be provided, each of which is disposed between any adjacent positive electrode sheets 211 or negative electrode sheets 212 .

[0111] As an example, the separator 213 may be provided continuously, and may be provided between any adjacent positive electrode sheets 211 or negative electrode sheets 212 by folding or winding.

[0112] In some embodiments, the battery cell 100 further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not specifically limit the type of electrolyte, and the electrolyte may be selected based on needs. The electrolyte may be liquid, gel, or solid.

[0113] In some embodiments, the electrode assembly 2 includes tabs 22 , which can conduct current from the electrode body 21 or introduce current into the electrode body 21 . The tabs 22 include a positive electrode tab 223 and a negative electrode tab 224 .

[0114] The electrode terminal 3 is provided through a mounting hole in the first wall 11 of the housing 1 and is partially located within the accommodating cavity 1a of the housing 1. The electrode terminal 3 is used to directly or indirectly electrically connect to the tab 22 of the electrode assembly 2 to output electrical energy to or input electrical energy to the electrode body 21 of the electrode assembly 2.

[0115] The first wall 11 is a wall surface of the housing 1 for mounting the electrode terminal 3. The first wall 11 and the other walls of the housing 1 together form a housing cavity 1a for accommodating the electrode assembly 2. In the embodiment of the present application, the electrode terminal 3 is mounted on the end cap, that is, the end cap constitutes the first wall 11 of the housing 1. In some other embodiments, if the electrode terminal 3 is mounted on another wall surface of the housing 1, the wall surface on which the electrode terminal 3 is mounted constitutes the first wall 11.

[0116] For example, the number of electrode terminals 3 may be only one, and the electrode terminal 3 is connected to one of the positive electrode tab 223 or the negative electrode tab 224, and the other of the positive electrode tab 223 or the negative electrode tab 224 is connected to the housing 1. The number of electrode terminals 3 may also be two, and the two electrode terminals 3 are connected to the positive electrode tab 223 and the negative electrode tab 224 respectively.

[0117] In an embodiment of the present application, the electrode terminal 3 includes a positive terminal 31 and a negative terminal 32, the positive terminal 31 is connected to the positive electrode tab 223, and the negative terminal 32 is connected to the negative electrode tab 224. Therefore, the shell 1 is correspondingly formed with two mounting holes, which are used to mount the positive terminal 31 and the negative terminal 32 respectively. It should be understood by those skilled in the art that in some other embodiments, the number of electrode terminals 3 can be more (more than two). When the number of electrode terminals 3 is multiple, the multiple electrode terminals 3 can be installed on the same wall surface of the shell 1, or on different wall surfaces of the shell 1. When the multiple electrode terminals 3 are respectively installed on different wall surfaces of the shell 1, each wall surface on which the electrode terminal 3 is installed can be constituted as the first wall 11.

[0118] Exemplarily, the electrode terminal 3 may be, for example, a pole, and the electrode terminal 3 may be made of a conductive material to achieve the conductive function of the electrode terminal 3 .

[0119] In the embodiment of the present application, the electrode terminal 3 is electrically connected to the tab 22 of the electrode assembly 2 via the electrical connector 4. The electrical connector 4 may also be referred to as a transition piece.

[0120] In the related art, when the pole tab is connected to the electrical connector, each pole tab with the same polarity will be separately welded to different positions of the electrical connector, thereby forming multiple weld marks on the electrical connector. In addition, in order to ensure the stability and reliability of welding, a certain process space needs to be reserved between the welding area (weld mark) and the edge of the electrical connector and between different welding areas. This requires the electrical connector to have sufficient width (dimension along the first direction), so that the width of the electrical connector is larger, and thus the thickness of the battery cell (dimension along the first direction) is larger.

[0121] As technology advances, devices are becoming increasingly integrated and miniaturized. Consequently, thinner battery cells are finding more and more applications. For example, in some installation spaces where installation space is extremely limited, thicker battery cells are clearly not suitable. To reduce the size of a battery cell, the number of electrode assemblies within the cell or the size of the electrode body may be reduced, which inevitably impacts the energy density of the cell.

[0122] In the embodiments of this application, Figure 3 、 Figure 5 、 Figure 6 and Figure 11 As shown, there are two electrode assemblies 2, and the electrode body 21 of each electrode assembly 2 leads to a positive electrode tab 223 and a negative electrode tab 224. That is, there are two tabs 22 with the same polarity, and the two tabs 22 with the same polarity are arranged at intervals along the first direction. The welding portions 221 of the tabs 22 with the same polarity at least partially overlap to form an overlapping portion 2211. Overlap refers to the position where the projections of the welding portions 221 of the tabs 22 overlap with each other in a projection plane perpendicular to the third direction.

[0123] The welding portion 221 is the portion of the tab 22 where welding is performed. The welding portion 221 is generally flat, which helps improve welding stability. However, those skilled in the art will appreciate that the welding portion 221 is not necessarily welded to the electrical connector 4 in its entirety, but rather at least partially welded to the electrical connector 4 in its entirety.

[0124] Since the tabs 22 are welded to the electrical connector 4 at the overlapping portion 2211, two tabs 22 of the same polarity can be simultaneously connected to the electrical connector 4 through a single welding operation, and only one weld mark 5 is formed after the welding is completed. In this way, the number of weld marks 5 formed after the tabs 22 are welded to the electrical connector 4 can be reduced, thereby saving the space occupied by the weld marks 5 on the electrical connector 4 and the process space required for welding the weld marks 5 on the electrical connector 4. This can appropriately reduce the size of the electrical connector 4, and further reduce the size of the battery cell 100, allowing the battery cell 100 to be better used in installation environments with relatively limited space without affecting the energy density of the battery cell 100.

[0125] In addition, since only one welding operation is required to connect the tab 22 to the electrical connector 4 , the number of welding operations can be reduced during the manufacturing process of the battery cell 100 , thereby improving production efficiency and production cycle time and reducing production costs.

[0126] like Figure 10 As shown, the number of electrode assemblies 2 in the housing 1 can be only one, and one electrode assembly 2 leads to two tabs with the same polarity. Figure 12 As shown, the number of electrode assemblies 2 in the shell 1 can be four, each electrode assembly 2 leads out a pole ear 22, and the pole ears 22 of each two adjacent electrode assemblies 2 overlap with each other to form an integral pole ear, and the two integral pole ears at least partially overlap to form an overlapping portion 2211, and are welded to the electrical connector 4 at the overlapping portion 2211.

[0127] The present embodiment of the present application does not impose any specific restrictions on the number of electrode assemblies 2 within the battery cell 100. The number of electrode assemblies 2 can be one, two, or more (more than two). The present embodiment of the present application also does not impose any specific restrictions on the number of tabs 22 extending from each electrode assembly 2 or the arrangement of the tabs 22. It is sufficient that only one weld mark 5 is formed after welding each tab 22 of the same polarity to the electrical connector 4. That is, each tab 22 of the same polarity can be connected to the electrical connector 4 by only one welding.

[0128] In the embodiment of the present application, the overlapping portion 2211 of the tab 22 can be welded to the electrical connector 4 via ultrasonic welding. Ultrasonic welding utilizes high-frequency vibration waves transmitted to the surfaces of the objects to be welded. Under pressure, these surfaces rub against each other, forming a fusion of molecular layers. Ultrasonic welding is a fast, clean, and efficient assembly process.

[0129] Of course, those skilled in the art should understand that in some other embodiments, the overlapping portion of the tab 22 may also be welded to the electrical connector 4 by any other welding method.

[0130] In some embodiments of the present application, the thickness direction of the electrode body 21 is the first direction. Along the first direction, the width of the overlapping portion 2211 is greater than the width of the weld mark 5.

[0131] In some embodiments, the thickness direction of the battery cell 100 can also be called the first direction, the direction relative to the large surface (the wall with the largest area) of the shell 1 can also be called the first direction, and the width direction of the electrical connector 4 can also be called the first direction. The first direction can also be the direction in which the positive electrode sheet 211, the negative electrode sheet 212 and the separator 213 of the electrode body 21 are stacked. Those skilled in the art should understand that when the electrode body 21 is a wound structure, the electrode body 21 includes a curved section and a straight section. At this time, the stacking direction of the positive electrode sheet, the negative electrode sheet and the separator of the straight section is the first direction. Figures 4 to 6 In the specific example shown, Figures 4 and 5 The up and down direction in the figure is the first direction of the embodiment of the present application.

[0132] Since the width of the overlapping portion 2211 is greater than the width of the weld mark 5 along the first direction, the weld mark 5 can be completely located in the overlapping area of the pole tabs 22 with the same polarity, thereby increasing the connection area between the pole tabs 22 at the overlapping portion 2211, so that the pole tabs 22 with the same polarity can be well welded to each other, the welding reliability is higher, the possibility of adverse conditions such as welding failure or cold welding is reduced, and the welding quality is improved.

[0133] In some embodiments of the present application, Figure 6 As shown, the welding mark 5 is located in the central area of the overlapping portion 2211.

[0134] The central area means that the distances between the two opposite sides of the welding mark 5 along the first direction and the two opposite sides of the overlapping part 2211 along the first direction are basically the same, and the distances between the two opposite sides of the welding mark 5 along the second direction and the two opposite sides of the overlapping part 2211 along the second direction are basically the same, that is, the welding mark 5 is generally symmetrically arranged along the central axis of the overlapping part 2211.

[0135] As a result, the welding reliability between the electrode tabs 22 having the same polarity can be further improved, so that the plurality of electrode tabs 22 at the overlapping portion 2211 can be sufficiently welded.

[0136] In addition, the weld mark 5 is located in the central area of the overlapping portion 2211 , which can ensure that the tabs 22 on two opposite sides along the first direction have the same extension length, thereby reducing the possibility of the tab 22 on one side being stretched too long, thereby improving the reliability of the battery cell 100 .

[0137] In some embodiments of the present application, the electrical connector 4 includes a tab connection portion 41, an electrode terminal connection portion 42, and an intermediate connection portion 43. The tab connection portion 41 connects to the tab 22, the electrode terminal connection portion 42 connects to the electrode terminal 3, and the intermediate connection portion 43 connects the tab connection portion 41 and the electrode terminal connection portion 42. The electrode terminal connection portion 42 and the tab connection portion 41 extend along the second direction, and the intermediate connection portion 43 extends along the third direction. The tab connection portion 41 is closer to the first wall 11 than the electrode terminal connection portion 42 in the third direction. The welding portion 221 of the tab 22 is welded to the side of the tab connection portion 41 facing away from the first wall 11. The first direction, the second direction, and the third direction are perpendicular to each other.

[0138] The extension direction of the tab connection portion 41 and the electrode terminal connection portion 42 is the second direction, which can also be called the length direction of the electrical connector 4. The extension direction of the intermediate connection portion 43 is the third direction, which can also be called the height direction. Figure 8 and Figure 9 In the specific example shown, Figure 8 and Figure 9 The left-right direction is the second direction implemented in this application, and the up-down direction is the third direction of the embodiment of this application.

[0139] like Figure 7 and Figure 9 As shown, the electrical connector 4 includes a tab connection portion 41, an electrode terminal connection portion 42, and an intermediate connection portion 43. The tab connection portion 41 is a structure in the electrical connector 4 for connecting to the tab 22, and the electrode terminal connection portion 42 is a structure in the electrical connector 4 for connecting to the electrode terminal 3.

[0140] Illustratively, the electrode terminal 3 may be welded to the electrode terminal connecting portion 42 by laser welding.

[0141] The intermediate connection portion 43 is a component of the electrical connector 4 that connects the tab connection portion 41 and the electrode terminal connection portion 42 . The tab connection portion 41 and the electrode terminal connection portion 42 are located on opposite sides of the intermediate connection portion 43 along the second direction.

[0142] In some embodiments, the intermediate connection portion 43 can be set as a fuse portion, that is, the intermediate connection portion 43 includes a thinning area and / or a fuse hole, so that the current exceeds the rated value, that is, when the current is too large, the intermediate connection portion 43 can be melted, thereby disconnecting the connection between the tab connection portion 41 and the electrode terminal connection portion 42, thereby cutting off the electrical connection between the tab 22 and the electrode terminal 3, reducing the possibility of short circuit in the battery cell 100, and making the battery cell 100 more reliable.

[0143] Exemplarily, the electrical connector 4 may be formed as an integrated structure. For example, a plate-like member may be prepared by processes such as stamping, bending, and cutting to form the integrated electrical connector 4 .

[0144] As another example, the tab connection portion 41 , the electrode terminal connection portion 42 and the intermediate connection portion 43 of the electrical connector 4 may be separate structures and then assembled together.

[0145] When multiple tabs 22 of the same polarity at least partially overlap to form an overlapping portion 2211, the overlapping portion 2211 will be larger in the third direction and may occupy part of the space within the accommodating cavity 1a. In the embodiment of the present application, since the intermediate connecting portion 43 extends along the third direction, there is a certain height difference between the tab connecting portion 41 and the electrode terminal connecting portion 42 along the third direction. This allows the overlapping portion 2211 of the tab 22 to be located within the space created by the height difference between the tab connecting portion 41 and the electrode terminal connecting portion 42. This prevents the overlapping portion 2211 from occupying too much space within the accommodating cavity 1a of the housing 1. This allows the tabs 22 to be welded to the electrical connector 4 in an overlapping manner without affecting the energy density of the battery cell 100.

[0146] In some embodiments of the present application, the battery cell 100 further includes an insulating member 6, which is located on the side of the first wall 11 facing the electrode assembly 2. Each tab 22 further includes a bent portion 222, which is connected to the welding portion 221. The bent portion 222 protrudes in the third direction relative to the welding portion 221 toward the side of the first wall 11. Along the first direction, the width of the tab connection portion 41 is less than the first dimension. The first dimension is the width of the insulating member 6 along the first direction minus the width of the bent portion 222 of each tab 22 connected to the tab connection portion 41 along the first direction.

[0147] The insulating member 6 is made of an insulating material and is located between the first wall 11 and the electrode assembly 2. The insulating member 6 can be prefabricated from a plastic integral part or assembled from various plastic parts. When the housing 1 is made of a metal material, the insulating member 6 can electrically insulate the electrode assembly 2 from the first wall 11, reducing the possibility of a short circuit caused by contact between the tab 22 and the first wall 11 made of a metal material. In addition, the insulating member 6 can also provide a certain degree of support for the electrode assembly 2, reducing the possibility of the electrode assembly 2 moving inside the accommodating chamber 1a.

[0148] Exemplarily, the insulating member 6 may be a plastic frame.

[0149] The tab 22 needs to be bent when connected to the tab connection portion 41. One end of the bent portion 222 is connected to the welding portion 221, and the other end is connected to the electrode body 21. The embodiment of the present application does not specifically limit the bending shape of the bent portion 222, and the tab 22 can be bent according to actual conditions.

[0150] For example, Figure 11 and Figure 13 As shown, the bent portion 222 of the tab 22 protrudes along the third direction toward the side where the first wall 11 is located relative to the welding portion 221. When observed along the second direction, the cross-section of the bent portion 222 of the embodiment of the present application is generally in an inverted U-shape, and one side wall of the bent portion 222 is generally inclined. In this way, the inclined side wall is not easy to interfere with the insulating part 6 (lower plastic) in the shell 1, and can make more full use of the space between the tab connecting portion 41 and the inner wall of the shell 1 to accommodate the bent portion 222 of the tab 22.

[0151] In addition, with Figure 12 Compared with the 90° bend of the tab 22 shown in FIG. Figure 11 and Figure 13 The structure of the tab 22 shown is more compact, and the overall size along the third direction is smaller, so that the tab 22 occupies less space, saving space in the accommodating cavity 1a of the shell 1, and thereby increasing the space in the accommodating cavity 1a for accommodating the electrode body 21, which is beneficial to improving the energy density of the battery cell 100.

[0152] For example, Figure 12 As shown, when viewed along the second direction, the bent portion 222 may be substantially in an inverted L-shape.

[0153] In the embodiment of the present application, when the width of the tab connection portion 41 is smaller than the first size, there is sufficient space in the shell 1 to accommodate the bent portion 222 of the tab 22, thereby meeting the process requirements for bending the tab 22 and improving the connection reliability between the tab 22 and the electrical connector 4.

[0154] Normally, the process dimension required for bending a single tab 22 is 3 mm. Therefore, when the tabs 22 extend from both sides relative to each other along the first direction, the process dimension required for bending the tab 22 is 6 mm, that is, at least 3 mm of space must be reserved between one side of the insulating part 6 and the edge of the tab connecting portion 41 to accommodate the bent portion 222 of the tab 22. Then, when there are tabs 22 on both sides, a total of at least 6 mm of space must be reserved.

[0155] In some embodiments of the present application, the first dimension is the width of the insulating member 6 along the first direction minus 6 mm.

[0156] like Figure 6As shown, the dimension of the insulating member 6 along the first direction is V, and the dimension of the tab connection portion along the first direction is W, then W<V-6, in millimeters (mm). Of course, those skilled in the art will understand that when the tab 22 is only extended from one side of the electrode assembly 2 along the first direction, W can be less than V-3.

[0157] Therefore, the process requirements for folding most of the tabs 22 can be met, so that there is a sufficient distance between the insulating member 6 and the tab connecting portion 41 to accommodate the bent portions 222 of most of the tabs 22 .

[0158] In some embodiments of the present application, along the first direction, the width of the tab connection portion 41 is greater than the width of the weld mark 5 .

[0159] Therefore, the tab connecting portion 41 can have enough space for welding the overlapping portion 2211 of the tab, thereby improving the welding reliability between the tab 22 and the electrical connector 4 .

[0160] Specifically, a certain process gap needs to be reserved when welding the tab 22 to the electrical connector 4 to improve welding reliability or reduce the possibility of adverse conditions such as welding failure due to errors. Typically, the process gap required on one side of the weld mark 5 is 1.5 mm, while the process gap required on both sides is 3 mm.

[0161] like Figure 6 As shown, the width of the weld mark 5 along the first direction is Z, then W>Z, and specifically, W>Z+3, the unit is millimeter (mm).

[0162] In this way, the process requirements for welding the tab 22 and the tab connecting portion 41 can be met, so that the tab connecting portion 41 has sufficient space to facilitate welding the overlapping portion 2211 of the tab 22 and the tab connecting portion 41, thereby improving the welding reliability when welding the tab 22 and the electrical connector 4.

[0163] In some embodiments of the present application, along the third direction, the height of the intermediate connecting portion 43 is the distance between the bottom end surface of the electrode terminal 3 and the insulating member 6 minus the distance between the tab connecting portion 41 and the insulating member 6 .

[0164] The bottom end surface of the electrode terminal 3 refers to the end surface of the electrode terminal 3 facing the electrode assembly 2 along the third direction.

[0165] like Figure 9 As shown, along the third direction, the distance between the bottom end surface of the electrode terminal 3 and the insulating member 6 is N, and the distance between the tab connecting portion 41 and the insulating member 6 is M. Then, the dimension of the intermediate connecting portion 43 along the third direction is NM.

[0166] A certain gap is reserved between the tab connection portion 41 and the insulating member 6 , thereby reserving a certain error space, which is more conducive to the installation of the electrical connector 4 .

[0167] Typically, along the third direction, the distance M between the tab connection portion 41 and the insulating member 6 is in the range of 0.1 mm to 0.3 mm. For example, M may be 0.1 mm, 0.2 mm, or 0.3 mm.

[0168] In this way, while ensuring the installation accuracy of the electrical connector 4, a height difference can be formed along the third direction between the pole tab connection part 41 of the electrical connector 4 and the electrode terminal connection part 42, so that the overlapping part 2211 of the pole tab 22 can be located in the space formed by the height difference, so that the overlapping part 2211 will not occupy too much space in the shell 1, and the pole tab 22 can be welded to the electrical connector 4 through a welding mark 5. The pole tab reduces the thickness of the battery cell 100 without affecting the energy density of the battery cell 100, reduces the number of welding times, and reduces production costs.

[0169] In some embodiments of the present application, at least one side of the tab connecting portion 41 along the first direction has an accommodating space 10 , and the bent portion 222 is accommodated in the accommodating space 10 .

[0170] In this way, the accommodating space 10 on the side of the electrical connector 4 along the first direction can be fully utilized, and the space occupied by the tab 22 in the height direction (third direction) can be reduced, so that the tab 22 is not located as a whole below the electrical connector 4, which is beneficial to improving the space utilization rate within the shell 1 of the battery cell 100, reserving more space for the electrode body 21, and thus being able to appropriately increase the volume of the electrode body 21 without changing the size of the shell 1 of the battery cell 100, thereby improving the energy density of the battery cell 100.

[0171] Along the third direction, the spatial area between the inner wall surface of the first wall 11 facing the accommodating cavity 1a and the surface of the pole tab connecting portion 41 facing away from the first wall 11, and along the first direction, the spatial area between the pole tab connecting portion 41 and the inner wall surface of the shell 1, the two spatial areas jointly define an accommodating space 10 for accommodating the bending portion 222.

[0172] For example, at least a portion of the tab connecting portion 41 may be recessed along the first direction to form a groove portion, and the groove portion defines at least a portion of the accommodation space 10 .

[0173] As another example, along the first direction, sufficient space may be reserved between the electrical connector 4 and the inner wall of the housing 1 , thereby forming an accommodating space 10 for accommodating the bent portion 222 of the tab 22 .

[0174] The embodiment of the present application does not impose any specific limitation on the formation method of the accommodation space 10 , as long as there is enough space to accommodate the tab 22 .

[0175] Along the third direction, the top surface of the bent portion 222 is substantially flush with the surface of the pole tab connecting portion 41 facing the first wall 11, or may be slightly higher than the surface of the pole tab connecting portion 41 facing the first wall 11. In this way, the area of the accommodating space 10 along the height direction can be fully utilized to accommodate more pole tabs 22, thereby providing a larger space for the electrode body 21 and increasing the energy density of the battery cell 100.

[0176] The top surface of the bent portion 222 refers to the surface of the bent portion 222 closest to the first wall 11 along the first direction. Flush means that the top surface of the bent portion 222 and the surface of the tab connection portion 41 facing the first wall 11 are substantially in the same horizontal plane.

[0177] Of course, those skilled in the art should understand that in some other embodiments, for example, when the length of the tab 22 is shorter, the top surface of the bent portion 222 may also be lower than the surface of the tab connecting portion 41 facing the first wall 11, and the user can set it according to actual conditions.

[0178] In some embodiments of the present application, along the first direction, the width of the bent portion 222 is smaller than the distance between the insulating member 6 and the tab connecting portion 41 .

[0179] In this way, while ensuring the good appearance of the tab 22, the bent portion 222 of the tab 22 can be accommodated in the accommodation space 10, thereby saving the space occupied by the tab 22 in the accommodation cavity 1a along the third direction, which is conducive to improving the energy density of the battery cell 100. In addition, the tab 22 is less likely to come into contact with the housing 1, reducing the possibility of a short circuit in the battery cell 100.

[0180] In some embodiments of the present application, the tab connection portion 41 is flat and / or the electrode terminal connection portion 42 is flat.

[0181] This is more conducive to connecting the electrode terminal 3 and the tab 22 to the electrode terminal connecting portion 42 and the tab connecting portion 41 respectively, thereby improving connection reliability and making the electrical connector 4 more stable.

[0182] Of course, those skilled in the art should understand that in some other embodiments, the tab connection portion 41 and the electrode terminal connection portion 42 may also be in any other suitable shapes.

[0183] In some embodiments of the present application, the electrode terminal 3 includes a positive terminal 31 and a negative terminal 32. The electrical connector 4 includes a first electrical connector 44 and a second electrical connector 45. The tab 22 includes a plurality of positive tabs 223 and negative tabs 224, each of which is located on the same side as the positive terminal 31 and / or each of which is located on the same side as the negative terminal 32. Each positive tab 223 is connected to the positive terminal 31 via the first electrical connector 44, and each negative tab 224 is connected to the negative terminal 32 via the second electrical connector 45.

[0184] As a result, the positive electrode tab 223 at least partially overlaps to form an overlapping portion 2211, and is welded to the first electrical connector 44 at the overlapping portion 2211. The negative electrode tab 224 at least partially overlaps to form an overlapping portion 2211, and is welded to the second electrical connector 45 at the overlapping portion 2211. As a result, the positive electrode tab 223 and the negative electrode tab 224 only need to be welded once to achieve connection with the first electrical connector 44 and the second electrical connector 45, reducing the number of welds, thereby improving production efficiency and reducing production costs. Moreover, since the positive electrode tab 223 and the negative electrode tab 224 each form only one weld mark 5 after being welded to the first electrical connector 44 and the second electrical connector 45, the thickness of the battery cell 100 can be reduced, making the battery cell 100 more suitable for installation environments with limited space.

[0185] In addition, since the positive electrode tab 223 and the positive terminal 31 are located on the same side, and / or the negative electrode tab 224 and the negative terminal 32 are located on the same side, it is easier to connect the tab 22 and the electrode terminal 3, and it can save space in the battery cell shell, which is beneficial to improving the energy density of the battery cell.

[0186] Illustratively, the positive electrode tab 223 is located on the same side as the positive electrode terminal 31 , and the negative electrode tab 224 is located on the same side as the negative electrode terminal 32 .

[0187] As another example, the positive electrode tab 223 is located on the same side as the positive electrode terminal 31 , and the negative electrode tab 224 is located on a different side from the negative electrode terminal 32 .

[0188] As another example, the positive electrode tab 223 and the positive electrode terminal 31 are located on different sides, and the negative electrode tab 224 and the negative electrode terminal 32 are located on the same side.

[0189] Those skilled in the art should understand that when the tab 22 and the electrode terminal 3 are located on the same side, the tab connection portion 41 of the electrical connector 4 is generally in the shape of a flat plate extending in one direction, and the positive tab 223 and the negative tab 224 can be located on the same side of the electrode body 21, or on different sides of the electrode body 21.

[0190] Illustratively, the positive electrode tab 223 and the negative electrode tab 224 are located on the same side of the electrode body 21 , and the positive terminal 31 and the negative terminal 32 are located on the same side as the positive electrode tab 223 and the negative electrode tab 224 .

[0191] As another example, the positive electrode tab 223 and the negative electrode tab 224 are located on different sides of the electrode body 21, the positive terminal 31 is located on the same side as the positive electrode tab 223, and the negative terminal 32 is located on the same side as the negative electrode tab 224.

[0192] In some embodiments of the present application, the electrode terminal 3 includes a positive terminal 31 and a negative terminal 32. The electrical connector 4 includes a first electrical connector 44 and a second electrical connector 45. The tab 22 includes a plurality of positive tabs 223 and a plurality of negative tabs 224, each of which is located on a different side from the positive terminal 31 and / or each of which is located on a different side from the negative terminal 32. The positive tab 223 is connected to the positive terminal 31 via the first electrical connector 44, and the negative tab 224 is connected to the negative terminal 32 via the second electrical connector 45.

[0193] As a result, the positive electrode tab 223 at least partially overlaps to form an overlapping portion 2211, and is welded to the first electrical connector 44 at the overlapping portion 2211. The negative electrode tab 224 at least partially overlaps to form an overlapping portion 2211, and is welded to the second electrical connector 45 at the overlapping portion 2211. As a result, the positive electrode tab 223 and the negative electrode tab 224 only need to be welded once to achieve connection with the first electrical connector 44 and the second electrical connector 45, reducing the number of welds, thereby improving production efficiency and reducing production costs. Moreover, since the positive electrode tab 223 and the negative electrode tab 224 each form only one weld mark 5 after being welded to the first electrical connector 44 and the second electrical connector 45, the thickness of the battery cell 100 can be reduced, making the battery cell 100 more suitable for installation environments with limited space.

[0194] In addition, since the positive electrode tab 223 and the positive terminal 31 are located on different sides, and / or the negative electrode tab 224 and the negative terminal 32 are located on different sides, this is beneficial to improving the flexibility of connecting the tab 22 and the electrode terminal 3, and when multiple battery cells 100 are grouped, it is beneficial to improve the connection flexibility between the battery cells 100.

[0195] Illustratively, the positive electrode tab 223 is located on a different side from the positive electrode terminal 31 , and the negative electrode tab 224 is located on a different side from the negative electrode terminal 32 .

[0196] As another example, the positive electrode tab 223 is located on the same side as the positive electrode terminal 31 , and the negative electrode tab 224 is located on a different side from the negative electrode terminal 32 .

[0197] As another example, the positive electrode tab 223 and the positive electrode terminal 31 are located on different sides, and the negative electrode tab 224 and the negative electrode terminal 32 are located on the same side.

[0198] Those skilled in the art should understand that when the tab 22 and the electrode terminal 3 are located on different sides, the tab connection portion 41 of the electrical connector 4 is generally "L"-shaped or inverted "L"-shaped, that is, the tab connection portion 41 includes two sections extending in different directions, one of which is in the same extension direction as the electrode terminal connection portion 42, and the other section is perpendicular to the extension direction of the electrode terminal connection portion 42, thereby connecting the electrode terminal 3 and the tab 22 located on different sides.

[0199] In addition, when the tab 22 and the electrode terminal 3 are located on different sides, the positive tab 223 and the negative tab 224 can also be located on the same side of the electrode body 21 or on different sides of the electrode body 21 .

[0200] Illustratively, the positive electrode tab 223 and the negative electrode tab 224 are located on the same side of the electrode body 21, and the positive terminal 31 and the negative terminal 32 are located on a side different from the side where the positive electrode tab 223 and the negative electrode tab 224 are located. At this time, the positive terminal 31 and the negative terminal 32 can be located on the same side or on different sides.

[0201] As another example, the positive electrode tab 223 and the negative electrode tab 224 are located on different sides of the electrode body 21 , and the positive terminal 31 and the negative terminal 32 are respectively located on sides different from the positive electrode tab 223 and the negative electrode tab 224 .

[0202] As another example, the positive electrode tab 223 , the negative electrode tab 224 , the positive electrode terminal 31 , and the negative electrode terminal 32 may be located on four different sides, respectively.

[0203] In some embodiments of the present application, there are multiple electrode assemblies 2 , which are arranged in parallel along the first direction, and the welding portions 221 of the tabs 22 with the same polarity of each electrode assembly 2 are connected through the same electrical connector 4 .

[0204] Multiple electrode assemblies 2 can increase the energy density of the battery cell 100. Furthermore, connecting the tabs 22 of the same polarity of multiple electrode assemblies 2 through the same electrical connector 4 can reduce the assembly steps of the battery cell 100, lower the assembly difficulty, and help reduce production costs.

[0205] A second aspect of the present application provides a battery device 400 , which includes a box body 401 and at least one battery cell 100 described in the first aspect of the present application. The battery cell 100 is accommodated in the box body 401 .

[0206] The battery device 400 provided in the present application includes the thinner battery cell 100 provided in the first aspect above, and thus can effectively reduce the size of the battery device 400, so that the battery device 400 can be installed in an installation environment with limited size, and has low production cost and high production efficiency.

[0207] In addition, when the size of the box 401 of the battery device 400 does not change, the box 401 can accommodate more battery cells 100, which is beneficial to improving the energy density of the battery device 400.

[0208] A third aspect of the present application provides an electrical device, which includes the battery cell 100 described in the first aspect of the present application or the battery device 400 described in the second aspect of the present application for providing electrical energy.

[0209] The electrical device of the embodiment of the present application includes the smaller battery cell 100 provided by the first aspect or the smaller battery device 400 provided by the second aspect. Therefore, more battery cells 100 or battery devices 400 can be arranged in the electrical device, which is beneficial to extending the power supply time of the battery cell 100 or battery device 400 to the electrical device, and can also provide good power supply to the electrical device when the space of the electrical device is limited.

[0210] A fourth aspect of the present application provides an energy storage device, which includes the battery cell 100 described in the first aspect of the present application or the battery device 400 described in the second aspect of the present application for providing electrical energy.

[0211] The energy storage device of the embodiment of the present application includes the smaller battery cells 100 provided by the first aspect or the smaller battery device 400 provided by the second aspect. Therefore, more battery cells 100 or battery devices 400 can be arranged in the energy storage device, which is beneficial to extending the power supply time of the battery cells 100 or battery devices 400 to the energy storage device. In addition, even when the space of the energy storage device is limited, it can provide good power supply to the energy storage device.

[0212] Below, some specific examples of embodiments of the present application are described with reference to the accompanying drawings.

[0213] As a specific example, a battery cell (battery unit 100) includes an adapter (electrical connector 4), a bare cell (electrode body 21), and a tab 22. The tab is connected to the bare cell. Tabs of the same polarity are overlapped and welded to the adapter via a weld mark 5.

[0214] The adapter is arranged in a Z-shaped structure, including a first part (electrode terminal connecting part 42), a second part (earth ear connecting part 41) and a connecting part (middle connecting part 43). The first part and the second part are spaced apart in the Z direction (third direction). The connecting part connects the first part and the second part. The first part is welded to the pole (electrode terminal 3), and the second part is welded to the ear. Compared with the first part, the second part is closer to the lower plastic (insulating part 6).

[0215] The overlapping area of the tabs (overlapping portion 2211) completely covers the weld print, and the weld print is symmetrical to the center line of the overlap.

[0216] The dimension W of the adapter along the thickness direction of the battery cell (the first direction) satisfies: V-6mm>W>Z+3mm; the width of the plastic under the battery cell (the dimension along the first direction) is V, and the width of the weld mark (the dimension along the first direction) is Z.

[0217] The above embodiments are intended only to illustrate the technical solutions of the present application, and are not intended to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they may modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. Such modifications or replacements do not deviate from the essence of the corresponding technical solutions and are intended to be included in the scope of the present application. In particular, as long as there is no structural conflict, the various technical features described in the various embodiments may be combined in any manner.

Claims

1. A battery cell, characterized in that: The battery cell comprises: A housing is formed with an accommodating cavity therein, the housing comprising a first wall, and the first wall is formed with a mounting hole; At least one electrode assembly is located in the accommodating cavity, the electrode assembly comprising an electrode body and an electrode tab connected to the electrode body; an electrode terminal, passing through the mounting hole; and An electrical connector, connecting the electrode terminal and the tab; Wherein, the tab includes a welding portion. When there are multiple tabs with the same polarity, the welding portions of the tabs with the same polarity at least partially overlap to form an overlapping portion, and the overlapping portion is welded to the electrical connector to form a weld mark.

2. The battery cell according to claim 1, wherein: The thickness direction of the electrode body is a first direction; Along the first direction, the width of the overlapping portion is greater than the width of the weld mark.

3. The battery cell according to claim 1, wherein: The weld mark is located in a central area of the overlapping portion.

4. The battery cell according to any one of claims 1 to 3, characterized in that: The electrical connector includes a tab connection portion, an electrode terminal connection portion, and an intermediate connection portion, wherein the tab connection portion is connected to the tab, the electrode terminal connection portion is connected to the electrode terminal, and the intermediate connection portion is connected to the tab connection portion and the electrode terminal connection portion; The electrode terminal connection portion and the tab connection portion extend along the second direction, the intermediate connection portion extends along the third direction, and the tab connection portion is closer to the first wall than the electrode terminal connection portion in the third direction; The welding portion of the tab is welded to a side of the tab connecting portion facing away from the first wall; The first direction, the second direction, and the third direction are perpendicular to each other.

5. The battery cell according to claim 4, characterized in that The battery cell further includes an insulating member, the insulating member being located on a side of the first wall facing the electrode assembly; Each of the tabs further includes a bent portion, the bent portion being connected to the welding portion, and the bent portion protruding relative to the welding portion toward the side where the first wall is located in the third direction; Along the first direction, the width of the tab connection portion is smaller than the first dimension; The first dimension is the width of the insulating member along the first direction minus the width of the bent portion of each of the tabs connected to the tab connecting portion along the first direction.

6. The battery cell according to claim 5, characterized in that The first dimension is the width of the insulating member along the first direction minus 6 mm.

7. The battery cell according to claim 5, characterized in that Along the first direction, the width of the tab connection portion is greater than the width of the weld mark.

8. The battery cell according to claim 5, characterized in that Along the third direction, the height of the intermediate connecting portion is the distance between the bottom end surface of the electrode terminal and the insulating member minus the distance between the tab connecting portion and the insulating member.

9. The battery cell according to claim 5, characterized in that: At least one side of the tab connection portion along the first direction has an accommodation space The bent portion is accommodated in the accommodation space.

10. The battery cell according to claim 9, characterized in that Along the first direction, the width of the bent portion is smaller than the distance between the insulating member and the tab connecting portion.

11. The battery cell according to any one of claims 1 to 3, characterized in that: The tab connection portion is flat; and / or The electrode terminal connecting portion is flat.

12. The battery cell according to any one of claims 1 to 3, characterized in that: The electrode terminals include a positive terminal and a negative terminal; The electrical connector includes a first electrical connector and a second electrical connector; The electrode tabs include multiple positive electrode tabs and multiple negative electrode tabs, each of the positive electrode tabs is located on the same side as the positive terminal, and / or each of the negative electrode tabs is located on the same side as the negative terminal, each of the positive electrode tabs is connected to the positive terminal through the first electrical connector, and each of the negative electrode tabs is connected to the negative terminal through the second electrical connector.

13. The battery cell according to any one of claims 1 to 3, characterized in that: The electrode terminals include a positive terminal and a negative terminal; The electrical connector includes a first electrical connector and a second electrical connector; The electrode tabs include multiple positive electrode tabs and multiple negative electrode tabs, each positive electrode tab is located on a different side from the positive terminal, and / or each negative electrode tab is located on a different side from the negative terminal, each positive electrode tab is connected to the positive terminal through the first electrical connector, and each negative electrode tab is connected to the negative terminal through the second electrical connector.

14. The battery cell according to any one of claims 1 to 3, characterized in that: There are multiple electrode assemblies, and the multiple electrode assemblies are arranged in parallel along the first direction. The welding parts of the electrode tabs with the same polarity of each electrode assembly are connected through the same electrical connector.

15. A battery device, characterized in that: The battery device comprises: Cabinet; and At least one battery cell according to any one of claims 1 to 14 is accommodated in the case.

16. An electrical device, characterized in that: The electrical device includes the battery cell according to any one of claims 1 to 14 or the battery device according to claim 15 for providing electrical energy.

17. An energy storage device, characterized in that: The energy storage device comprises the battery cell according to any one of claims 1 to 14 or the battery device according to claim 15 for providing electrical energy.

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