Battery device, electric equipment and energy storage equipment

Abstract

The utility model provides a battery device, electric equipment and energy storage equipment, and belongs to the technical field of batteries. The battery device comprises a battery monomer and a connecting piece, wherein the battery monomer comprises an electrode terminal; the connecting piece comprises a first surface and a second surface which are oppositely arranged along the thickness direction, and the second surface faces the electrode terminal; the connecting piece further comprises a hollowed-out groove penetrating in the thickness direction, the hollowed-out groove is configured to be used for containing brazing filler metal, and the connecting piece is connected with the electrode terminal through the brazing filler metal filled in the hollowed-out groove; wherein the hollow groove comprises a first opening penetrating through the first surface and a second opening penetrating through the second surface, the orthographic projection of the second opening on the first surface completely falls into the range of the first opening, and the orthographic projection area of the second opening on the first surface is smaller than the area of the first opening. According to the embodiment of the invention, the welding quality between internal components of the battery device can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery device, an electrical device, and an energy storage device. Background Art

[0002] Energy conservation and emission reduction are key to sustainable social development. Rechargeable batteries, with their ability to store and release energy as needed, are widely used in various electrical devices and energy storage devices, playing a crucial role in promoting energy transformation and sustainable development. Battery technology is a crucial factor in the development of the new energy industry.

[0003] In a battery device, the electrode terminals of the battery cells need to be connected to connectors, which in turn communicate with other components to enable the input and output of electrical energy from the battery device. However, insufficient connection strength between the connectors and the electrode terminals can easily lead to cracking, thereby affecting the performance of the battery device. Utility Model Content

[0004] The present application aims to solve at least one of the technical problems existing in the background technology. To this end, one purpose of the present application is to provide a battery device, an electrical device, and an energy storage device to improve the connection strength between the connector and the electrode terminal, thereby improving the performance of the battery device.

[0005] An embodiment of the first aspect of the present application provides a battery device, which includes a battery cell and a connector, the battery cell includes an electrode terminal; the connector includes a first surface and a second surface arranged opposite to each other along the thickness direction, the second surface facing the electrode terminal; the connector also includes a hollow groove running through the thickness direction, the hollow groove is configured to accommodate solder, and the connector is connected to the electrode terminal through the solder filled in the hollow groove; wherein the hollow groove includes a first opening running through the first surface and a second opening running through the second surface, the orthographic projection of the second opening on the first surface completely falls within the range of the first opening, and the orthographic projection area of ​​the second opening on the first surface is smaller than the area of ​​the first opening.

[0006] In the technical solution of the embodiment of the present application, the connector is connected to the electrode terminal by using solder, which is simple to operate and will not damage the structural parts around the electrode terminal. At the same time, the design of the first opening being larger than the second opening facilitates filling and melting the solder, and can also increase the contact area between the solder and the connector, thereby improving the connection strength between the connector and the electrode terminal and enhancing the performance of the battery device.

[0007] In some embodiments, the cross-sectional area of ​​the hollow groove gradually increases along the direction from the second surface to the first surface. The design of gradually increasing the cross-sectional area of ​​the hollow groove helps the molten solder to be tightly filled in the hollow groove, thereby improving the quality of the solder-connector welding.

[0008] In some embodiments, the orthographic projection of the second opening completely falls within the orthographic projection of the electrode terminal in a plane perpendicular to the thickness of the connector. By ensuring that the orthographic projection of the second opening completely falls within the orthographic projection of the electrode terminal, the connector and the electrode terminal can be better welded using solder, thereby improving the connection strength between the connector and the electrode terminal.

[0009] In some embodiments, the hollow groove includes two end surfaces arranged along the extension direction, with the spacing between the two end surfaces gradually increasing in the extension direction along the direction from the second surface to the first surface. By adopting a design in which the spacing between the two end surfaces gradually increases in the extension direction, the welding quality of the welding starting and ending ends can be improved, thereby improving the quality of the connection parts welded using the hollow groove.

[0010] In some embodiments, the hollow groove further includes two side surfaces arranged perpendicular to the extension direction, with the spacing between the two side surfaces gradually increasing in the direction perpendicular to the extension direction along the direction from the second surface to the first surface. By adopting a design in which the spacing between the two side surfaces gradually increases in the direction perpendicular to the extension direction, the quality of the welding between the side surfaces and the solder can be improved, thereby improving the quality of the entire welding process.

[0011] In some embodiments, the angle α1 between the end face and the first surface and the angle α2 between the side face and the first surface satisfy α1≤α2. While ensuring welding quality, the amount of solder used and the welding time are minimized.

[0012] In some embodiments, the angle α1 between the end face and the first surface satisfies 30°≤α1≤60°. By limiting the angle α1 between the end face and the first surface to between 30° and 60°, the requirements for solder melting and welding at both the starting and ending ends can be met while minimizing solder waste and welding time caused by excessively small end face inclination angles, thereby improving welding quality.

[0013] In some embodiments, the angle α2 between the side surface and the first surface satisfies 45°≤α2≤75°. By limiting the angle α2 between the side surface and the first surface to between 45° and 75°, the need for preheating the interface between the side surface and the electrode terminal can be taken into account while minimizing the waste of solder and welding time caused by excessively small side inclination angles, thereby improving welding quality.

[0014] In some embodiments, the hollow slot includes multiple hollow sub-slots, each of which is spaced apart. The connector is connected to the same electrode terminal via solder filled in the multiple hollow sub-slots. By connecting the connector to the same electrode terminal using multiple hollow sub-slots, multi-position welding can improve welding stability and quality compared to single-position welding while ensuring a sufficient flow area.

[0015] In some embodiments, the connector further comprises a through hole extending through the first and second surfaces along the thickness direction, wherein the shortest distance between the through hole and the hollow groove is greater than or equal to 1 mm and less than or equal to 5 mm. By limiting the shortest distance between the through hole and the hollow groove to between 1 mm and 5 mm, the accuracy of welding quality detection using the through hole is improved, allowing for rapid screening of unqualified welding locations.

[0016] In some embodiments, the connector further includes a first portion and a second portion connected to each other, each of the first portion and the second portion having a hollowed-out groove, and the first portion and the second portion are respectively connected to the electrode terminals of different battery cells through the hollowed-out groove. By connecting the first portion and the second portion to the electrode terminals of different battery cells through the hollowed-out groove, current communication between different battery cells can be achieved, thereby achieving current communication within the battery device.

[0017] In some embodiments, the connector further includes an elastic connector portion, which is used to connect the first portion and the second portion. The elastic connector portion is configured to elastically deform when subjected to force to adjust the distance between the first portion and the second portion. By utilizing the elastic connector portion, the distance between the first portion and the second portion can be appropriately adjusted according to actual needs, reducing the risk of cracking between the electrode terminal and the connector due to changes in the battery cell structure and improving the stability of the connection.

[0018] In some embodiments, the elastic connection portion includes at least one through hole extending through the thickness direction. By adopting the through hole design for the elastic connection portion, the structure is simple and the manufacturing is convenient, which is conducive to the rapid mass production of the connector.

[0019] In some embodiments, the battery device further includes a battery cell assembly and an integrated busbar. The battery cell assembly includes a plurality of battery cells arranged along a first direction and an end plate for clamping the plurality of battery cells. The integrated busbar includes a body and a plurality of connectors connected thereto. The body is connected to the end plate, and the plurality of battery cells are connected in series via the connectors. In some embodiments, the plurality of battery cells are connected in parallel via the connectors. By connecting the plurality of connectors to the integrated busbar and utilizing the connection between the integrated busbar and the end plate to achieve positioning of the plurality of connectors, time is saved in adjusting the connectors individually and welding quality is improved.

[0020] In some embodiments, the connector has a positioning hole and the body has a positioning boss, and the positioning hole is configured to cooperate with the positioning boss to limit and fix the connector. By using the positioning hole and the positioning boss to cooperate to achieve rapid fixation of multiple connectors, assembly time can be saved and assembly efficiency can be improved.

[0021] An embodiment of the second aspect of the present application provides an electrical device, which includes the battery device in the above embodiment, and the battery device is used to provide electrical energy.

[0022] An embodiment of the third aspect of the present application provides an energy storage device, which includes the battery device in the above embodiment, and the energy storage device is used to store electrical energy.

[0023] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar components or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0025] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0026] Figure 2 A schematic diagram of the exploded structure of a battery device provided in some embodiments of the present application;

[0027] Figure 3 A schematic diagram of the exploded structure of a battery cell provided in some embodiments of the present application;

[0028] Figure 4 A schematic diagram of the structure of the connection between the connector and the battery cell provided in some embodiments of the present application;

[0029] Figure 5 A schematic structural diagram of a connector provided in some embodiments of the present application;

[0030] Figure 6 A top view of a connector provided in some embodiments of the present application;

[0031] Figure 7 for Figure 6 Sectional view of the AA section;

[0032] Figure 8 for Figure 7A schematic diagram of the partially enlarged structure of part C in the middle;

[0033] Figure 9 for Figure 6 Cross-sectional view of the middle BB part;

[0034] Figure 10 for Figure 9 Schematic diagram of the partially enlarged structure of part D in the middle.

[0035] Description of reference numerals:

[0036] 10. Vehicle; 100. Battery device; 200. Controller; 300. Motor; 110. Housing; 111. First portion; 112. Second portion; 120. Battery cell; 121. End cap; 1211. Electrode terminal; 122. Housing; 123. Electrode assembly; 1231. Tab; 130. Connector; 131. First surface; 132. Second surface; 133. Through hole; 134. First portion; 135. Second portion; 136. Elastic connecting portion; 1361. Via hole; 137. Positioning hole; 140. Hollow groove; 141. First opening; 142. Second opening; 143. Hollow sub-groove; 144. End face; 145. Side face. DETAILED DESCRIPTION

[0037] 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.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0039] In the description of the embodiments of this application, the technical terms "first" and "second" 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 clearly and specifically defined.

[0040] 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.

[0041] 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.

[0042] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0043] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and 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 and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0044] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; 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.

[0045] Currently, market developments indicate that rechargeable batteries are becoming increasingly widely used. 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 various electronic devices, including electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. As the application areas of rechargeable batteries continue to expand, market demand is also growing.

[0046] The battery device includes battery cells and a housing. The housing is used to accommodate multiple battery cells, as well as connectors between adjacent battery cells. The connectors are used to transmit current between the multiple battery cells, allowing the battery device to normally input or output electrical energy.

[0047] In some embodiments, the connector is connected to the electrode terminal by bolt connection. This solution has the problem of loose bolts and low production efficiency.

[0048] In some embodiments, laser deep penetration welding is used to weld the connector to the electrode terminal. This solution requires a large amount of heat input and can easily damage the structural parts around the electrode terminal. In addition, because the connector contains low-boiling-point metal elements, the molten metal in the molten pool may have upward recoil pressure, reducing the connection strength. At the same time, the liquid metal flying out of the molten pool may also cause damage to the components around the battery cell.

[0049] In order to solve the above problems, an embodiment of the first aspect of the present application provides a battery device, which includes a battery cell and a connector, the battery cell includes an electrode terminal; the connector includes a first surface and a second surface arranged opposite to each other along the thickness direction, the second surface facing the electrode terminal; the connector also includes a hollow groove running through the thickness direction, the hollow groove is configured to accommodate solder, and the connector is connected to the electrode terminal through the solder filled in the hollow groove; wherein the hollow groove includes a first opening running through the first surface and a second opening running through the second surface, the orthographic projection of the second opening on the first surface completely falls within the range of the first opening, and the orthographic projection area of ​​the second opening on the first surface is smaller than the area of ​​the first opening.

[0050] By using solder to connect the connector to the electrode terminal, the operation is simple and will not damage the structural parts around the electrode terminal. At the same time, the design of the first opening being larger than the second opening facilitates the filling and melting of the solder, and can also increase the contact area between the solder and the connector, thereby improving the connection strength between the connector and the electrode terminal and enhancing the performance of the battery device.

[0051] The battery devices disclosed in the embodiments of this application can be used, but are not limited to, in electrical equipment or energy storage devices such as vehicles, ships, or aircraft. The battery devices disclosed in this application can be used to form a power supply system for the electrical equipment or energy storage device, thereby improving the performance of the battery devices.

[0052] The present invention provides an electrical device that uses a battery device as a power source. The electrical device may include, 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, and the like. 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, and the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like.

[0053] An embodiment of the present application also provides an energy storage device that uses a battery device as a power source. The energy storage device may be, but is not limited to, an energy storage container, an energy storage cabinet, an energy storage power station, an energy storage battery pack, or a portable energy storage system.

[0054] For the convenience of description, the following embodiments are described by taking a vehicle 10 as an example of an electrical device according to an embodiment of the present application.

[0055] Please refer to Figure 1 , Figure 1 Schematic diagram of the structure of the vehicle provided for some embodiments of the present application. The vehicle 10 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery device 100 is provided inside the vehicle 10, and the battery device 100 can be provided at the bottom, head or tail of the vehicle 10. The battery device 100 can be used to power the vehicle 10. For example, the battery device 100 can serve as an operating power source for the vehicle 10. The vehicle 10 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to power the motor 300, for example, for starting, navigating and operating power requirements of the vehicle 10 during driving.

[0056] In some embodiments of the present application, the battery device 100 can serve not only as an operating power source for the vehicle 10 , but also as a driving power source for the vehicle 10 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 10 .

[0057] Please refer to Figure 2 , Figure 2Schematic diagram of the exploded structure of a battery device provided in some embodiments of the present application. The battery device 100 includes a housing 110 and a battery cell 120, and the battery cell 120 is accommodated in the housing 110. The housing 110 is used to provide a storage space for the battery cell 120, and the housing 110 can adopt a variety of structures. In some embodiments, the housing 110 may include a first portion 111 and a second portion 112, and the first portion 111 and the second portion 112 cover each other, and the first portion 111 and the second portion 112 jointly define a storage space for accommodating the battery cell 120. The second portion 112 may be a hollow structure with one end open, and the first portion 111 may be a plate-like structure, and the first portion 111 covers the open side of the second portion 112, so that the first portion 111 and the second portion 112 jointly define a storage space; the first portion 111 and the second portion 112 may also be hollow structures with one side open, and the open side of the first portion 111 covers the open side of the second portion 112. Of course, the box body 110 formed by the first part 111 and the second part 112 can be in various shapes, such as a cylinder, a cuboid, etc.

[0058] In the battery device 100, there may be multiple battery cells 120, and the multiple battery cells 120 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 120. The multiple battery cells 120 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery unit 120 may be housed within the housing 110. Of course, the battery device 100 may also be a battery module formed by first connecting the multiple battery cells 120 in series, in parallel, or in a hybrid connection, and then the multiple battery modules are further connected in series, in parallel, or in a hybrid connection to form an entire battery unit, which is then housed within the housing 110. The battery device 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 120.

[0059] Each battery cell 120 may be a secondary battery or a primary battery, a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 120 may be cylindrical, flat, rectangular, or in other shapes.

[0060] Please refer to Figure 3 , Figure 3 Schematic diagram of the decomposition structure of a battery cell provided in some embodiments of the present application. Battery cell 120 refers to the smallest unit that constitutes a battery device. Figure 3 The battery cell 120 includes an end cap 121 , a shell 122 , an electrode assembly 123 and other functional components.

[0061] The end cap 121 is a component that covers the opening of the housing 122 to isolate the internal environment of the battery cell 120 from the external environment. The shape of the end cap 121 can be adapted to the shape of the housing 122 to fit the housing 122. Optionally, the end cap 121 can be made of a material with a certain degree of hardness and strength (such as an aluminum alloy). This prevents deformation of the end cap 121 under pressure or collision, providing the battery cell 120 with greater structural strength and improved reliability. The end cap 121 can be provided with functional components such as electrode terminals 1211. The electrode terminals 1211 can be used to electrically connect to the electrode assembly 123 to transfer electrical energy to or from the battery cell 120. In some embodiments, the end cap 121 can also be provided with a pressure relief mechanism to release internal pressure when the internal pressure or temperature of the battery cell 120 reaches a threshold. The end cap 121 can also be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, and plastic. In some embodiments, an insulating member may be provided inside the end cap 121 to isolate the electrical connection components in the housing 122 from the end cap 121 to improve reliability. For example, the insulating member may be made of plastic, rubber, or the like.

[0062] The housing 122 is a component that cooperates with the end cap 121 to form the internal environment of the battery cell 120. This internal environment can accommodate the electrode assembly 123, electrolyte, and other components. The housing 122 and end cap 121 can be separate components. An opening can be provided in the housing 122, and the end cap 121 can be placed over the opening to form the internal environment of the battery cell 120. Alternatively, the end cap 121 and housing 122 can be integrated. Specifically, the end cap 121 and housing 122 can form a common connection surface before other components are inserted into the housing. When the interior of the housing 122 is to be enclosed, the end cap 121 can be placed over the housing 122. The housing 122 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylinder, or a hexagonal prism. Specifically, the shape of the housing 122 can be determined based on the specific shape and size of the electrode assembly 123. The housing 122 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0063] The electrode assembly 123 is a component in the battery cell 120 where electrochemical reactions occur. One or more electrode assemblies 123 may be contained in the housing 122. The electrode assembly 123 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active materials constitute the main body of the electrode assembly, and the parts of the positive and negative electrode sheets without active materials each constitute a tab 1231. The positive and negative electrode tabs may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery, the positive active material and the negative active material react with the electrolyte, and the tabs 1231 connect the electrode terminals to form a current loop.

[0064] An embodiment of the present application provides a battery device 100, which includes a battery cell 120 and a connector 130, the battery cell 120 includes an electrode terminal 1211; the connector 130 includes a first surface 131 and a second surface 132 arranged opposite to each other along the thickness direction, and the second surface 132 faces the electrode terminal 1211; the connector 130 also includes a hollow groove 140 extending through the thickness direction, the hollow groove 140 is configured to accommodate solder, and the connector 130 is connected to the electrode terminal 1211 through the solder filled in the hollow groove 140; wherein the hollow groove 140 includes a first opening 141 extending through the first surface 131 and a second opening 142 extending through the second surface 132, the orthographic projection of the second opening 142 on the first surface 131 completely falls within the range of the first opening 141, and the orthographic projection area of ​​the second opening 142 on the first surface 131 is smaller than the area of ​​the first opening 141.

[0065] Combine Figures 3 to 5 As shown, the battery cell 120 includes an end cap 121 and a shell 122 . The shell 122 is formed with an accommodating cavity having an opening for accommodating the electrode assembly 123 . The end cap 121 covers the opening of the shell 122 to seal the accommodating cavity.

[0066] In some embodiments, the electrode terminal 1211 is disposed on the end cap 121 , and the electrode terminal 1211 may include a positive terminal and a negative terminal.

[0067] The connector 130 is a structure used to connect the auxiliary electrode terminal 1211 with other components. For example, the connector 130 connects the electrode terminals 1211 of two battery cells 120, so that the two battery cells 120 form a series structure or a parallel structure. The material of the connector 130 can be the same as or different from the material of the electrode terminal 1211.

[0068] The connector 130 has a first surface 131 and a second surface 132 in the thickness direction, and the thickness direction is the direction of the height of the battery cell 120, that is, Figure 4The second surface 132 faces the electrode terminal 1211 and contacts the electrode terminal 1211 .

[0069] The hollow groove 140 extends through the connector 130 along its thickness and is used to accommodate solder. The solder is melted within the hollow groove 140, causing the melted solder to contact and connect with the inner wall of the hollow groove 140 and the surface of the electrode terminal 1211, thereby achieving welding between the connector 130 and the electrode terminal 1211. The material of the solder is not limited, and examples include tin-based solder, nickel-based solder, copper-based solder, and the like.

[0070] The hollow groove 140 can be constructed in any type, such as a straight-line hollow groove or a curved hollow groove. The size of the hollow groove 140 affects the flow area formed by the connection between the connector 130 and the electrode terminal 1211. The size of the hollow groove 140 is not limited, as long as it meets the flow area requirements.

[0071] In some embodiments, the solder can be placed in the hollow groove 140 first, and then melted and filled with laser. In some embodiments, the hollow groove 140 is a strip groove, and the solder can be heated and filled with solder using a filler wire head for welding.

[0072] The first surface 131 faces away from the electrode terminal 1211 . The first opening 141 penetrates the first surface 131 of the connector 130 and serves as a hollow groove 140 for placing an inlet of solder. The shape of the first opening 141 can be circular, rectangular, or the like.

[0073] The second surface 132 faces the electrode terminal 1211 and contacts the electrode terminal 1211 . The second opening 142 penetrates the second surface 132 of the connector 130 , facing the electrode terminal 1211 . The shape of the second opening 142 can be circular, rectangular, or the like.

[0074] The inner wall of the hollow groove 140 is located between the first opening 141 and the second opening 142. The melted solder connects to the electrode terminal 1211 opposite the second opening 142 and the inner wall of the hollow groove 140, thereby connecting the electrode terminal 1211 to the connector 130.

[0075] The orthographic projection of the second opening 142 on the first surface 131 completely falls within the range of the first opening 141, and the orthographic projection area of ​​the second opening 142 on the first surface 131 is smaller than the area of ​​the first opening 141. This means that the size of the first opening 141 is larger than that of the second opening 142, which facilitates the addition and melting of solder. The melted solder also gathers toward the second opening 142, which helps improve tightness and allows the melted solder to cover the portion of the electrode terminal 1211 facing the second opening 142 as much as possible, thereby improving welding quality.

[0076] By using solder to connect the connector 130 to the electrode terminal 1211, the operation is simple and will not damage the structural parts around the electrode terminal 1211. At the same time, the design of the first opening 141 being larger than the second opening 142 helps to fill and melt the solder, and can also increase the contact area between the solder and the connector 130, thereby improving the connection strength between the connector 130 and the electrode terminal 1211 and enhancing the performance of the battery device 100.

[0077] According to some embodiments of the present application, the cross-sectional area of ​​the hollow groove 140 gradually increases along the direction from the second surface 132 to the first surface 131 .

[0078] The direction from the second surface 132 to the first surface 131 refers to the direction from the end close to the electrode terminal 1211 to the direction away from the electrode terminal 1211 in the thickness direction of the connector 130. Figure 4 and Figure 5 Middle third direction Z.

[0079] The cross section of the hollow groove 140 is perpendicular to the plane where the thickness direction of the connecting member 130 is located.

[0080] The cross-sectional area of ​​the hollow groove 140 gradually increases, which means that the inner wall surface of the hollow groove 140 between the first opening 141 and the second opening 142 gradually changes, which helps the melted solder to make good contact with the inner wall surface of the hollow groove 140 and improve the welding quality.

[0081] The design of gradually increasing the cross-sectional area of ​​the hollow groove 140 helps the molten solder to be tightly filled in the hollow groove 140 , thereby improving the welding quality between the solder and the connector 130 .

[0082] According to some embodiments of the present application, in a plane perpendicular to the thickness direction of the connector 130 , the orthographic projection of the second opening 142 completely falls within the orthographic projection range of the electrode terminal 1211 .

[0083] The thickness direction of the connector 130 may be the height direction of the battery cell 120 , and a plane perpendicular to this direction is any horizontal plane, for example, the first surface 131 of the connector 130 or the second surface 132 of the connector 130 .

[0084] The orthographic projection of the second opening 142 completely falls within the orthographic projection range of the electrode terminal 1211, which means that the orthographic projection area of ​​the second opening 142 is less than or equal to the orthographic projection area of ​​the electrode terminal 1211. It can be understood that the electrode terminal 1211 supports the connecting piece 130 and can block the second opening 142, so that the solder can better connect the connecting piece 130 and the electrode terminal 1211.

[0085] By making the orthographic projection of the second opening 142 completely fall within the orthographic projection range of the electrode terminal 1211 , the solder can be better utilized to weld the connector 130 and the electrode terminal 1211 , thereby improving the welding strength between the connector 130 and the electrode terminal 1211 .

[0086] According to some embodiments of the present application, the hollow groove 140 includes two end surfaces 144 arranged along the extension direction, along the direction of the second surface 132 pointing to the first surface 131, and the spacing between the two end surfaces 144 gradually increases in the extension direction.

[0087] There are two ways to add solder during soldering: one is to first place the solder in the hollow groove 140 and then melt the solder in the hollow groove 140 for soldering; the other is to use a filler wire to heat and melt while filling. Both filling methods can melt and fill from one end of the hollow groove 140 to the other.

[0088] like Figures 6 to 8 As shown, the hollow groove 140 includes two end surfaces 144 arranged along the extension direction, that is, Figures 6 to 8 The first direction X is shown in FIG. One of the two end surfaces 144 is the starting end of filling, and the other end surface is the ending end of filling. The extending direction of the hollow groove 140 is not limited, for example, a linear hollow groove, an "L"-shaped hollow groove, etc.

[0089] Along the direction from the second surface 132 to the first surface 131 , the distance between the two end surfaces 144 gradually increases in the extension direction, which means that the hollow groove 140 is a hollow groove with flared ends, and both end surfaces 144 are inclined surfaces and form an angle with the first surface 131 .

[0090] Considering that when using laser to melt the solder, the energy generated by the laser device when it is just started is small, the melted solder is limited, and at this moment the end face 144 is a slope, and less solder needs to be filled on it. The solder melted by the laser device at the starting end can meet the solder required by the end face 144 at the starting end, reducing the probability of holes occurring at the starting end and reducing the risk of poor welding at the starting end due to limited laser energy.

[0091] Moreover, at the final stage of welding, since the laser device maintains a relatively high energy, the end face 144 of the terminal end of the hollow groove 140 is a bevel that can shield the laser energy, thereby avoiding as much as possible the damage to the electrode terminal 1211 caused by the laser hitting the electrode terminal 1211 after the solder melts, or even the problem of leakage.

[0092] By adopting a design in which the spacing between the two end faces 144 gradually increases in the extension direction, the welding quality of the welding starting end and the welding ending end can be improved, thereby improving the welding quality of the connecting member 130 using the hollow groove 140.

[0093] According to some embodiments of the present application, the hollow groove 140 further includes two side surfaces 145 arranged perpendicular to the extension direction, along the direction of the second surface 132 pointing to the first surface 131 , and the spacing between the two side surfaces 145 in the direction perpendicular to the extension direction gradually increases.

[0094] like Figure 6 、 Figure 9 and Figure 10 As shown, along the direction from the second surface 132 to the first surface 131, the spacing between the two side surfaces 145 increases gradually in the direction perpendicular to the extension direction. Figure 6 、 Figure 9 and Figure 10 The second direction Y shown in FIG means that the hollow groove 140 is a flared hollow groove, and both side surfaces 145 are inclined surfaces and have an angle with the first surface 131.

[0095] Both side surfaces 145 are flared bevels. In some embodiments, using a filler wire head to heat and melt while filling can reduce the probability of interference between the brazing material and the connector 130 during the filler wire brazing process, thereby causing the connector 130 to shift.

[0096] At the same time, considering that the laser device may swing slightly when melting the solder, the side surfaces 145 are all flared bevels, which help the laser to preheat the side surfaces 145, especially the junction between the side surfaces 145 and the electrode terminal 1211, so that the melted solder can be better welded to the side surfaces 145 and the electrode terminal 1211 surface.

[0097] By adopting a design in which the spacing between the two side surfaces 145 is gradually increased in a direction perpendicular to the extension direction, the quality of welding between the side surfaces 145 and the solder can be improved, thereby improving the quality of the entire welding.

[0098] According to some embodiments of the present application, an included angle α1 between the end surface 144 and the first surface 131 and an included angle α2 between the side surface 145 and the first surface 131 satisfy: α1≤α2.

[0099] like Figure 8 and Figure 10 As shown, the intersection of the end surface 144 and the first surface 131 is a plane-to-plane intersection. The angle between the two surfaces has two values, and the sum of the two values ​​is 180°. For ease of description, the angle α1 between the end surface 144 and the first surface 131 is the smaller of the two values. Similarly, the angle α2 between the side surface 145 and the first surface 131 is the smaller of the two values.

[0100] The included angle α1 between the end face 144 and the first surface 131 is less than or equal to the included angle α2 between the side face 145 and the first surface 131, meaning that the inclination angle of the end face 144 is less than or equal to the inclination angle of the side face 145. The larger the inclination angle of the side face 145, the smaller the space above the side face 145, the less solder is required, and this can reduce the amount of solder used and shorten the welding time accordingly.

[0101] By designing that the angle α1 between the end face 144 and the first surface 131 and the angle α2 between the side face 145 and the first surface 131 satisfy α1≤α2, the amount of solder used can be saved as much as possible and the welding time can be shortened while meeting the welding quality.

[0102] According to some embodiments of the present application, the included angle α1 between the end surface 144 and the first surface 131 satisfies 30°≤α1≤60°.

[0103] like Figure 8 As shown, the angle α1 between the end surface 144 and the first surface can be specifically 30°, 35°, 40°, 45°, 50°, 55°, 60°, or a value between any two adjacent values ​​mentioned above.

[0104] In some embodiments, the angle α1 between the end face 144 and the first surface 131 is 30°. The inclination angle of the end face 144 is not large, which can meet the requirements of welding quality and reduce the waste of solder and welding time caused by the need to use more solder due to the small inclination angle of the end face 144.

[0105] In some embodiments, the included angle α1 between the end surface 144 and the first surface 131 is 60°. The end surface 144 has a relatively large inclination angle, which can meet the requirements of solder melting and welding at the starting end and the ending end.

[0106] By limiting the angle α1 between the end face 144 and the first surface 131 to between 30° and 60°, the requirements for solder melting and welding at the starting end and the ending end can be taken into account, while minimizing the waste of solder caused by the small inclination angle of the end face 144 and the consumption of welding time, thereby improving the welding quality.

[0107] According to some embodiments of the present application, an included angle α2 between the side surface 145 and the first surface 131 satisfies 45°≤α2≤75°.

[0108] like Figure 10 As shown, the angle α2 between the side surface 145 and the first surface 131 can be specifically 45°, 50°, 55°, 60°, 65°, 70°, 75°, or a value between any two adjacent values ​​mentioned above.

[0109] In some embodiments, the angle α2 between the side surface 145 and the first surface 131 is 45°, which can meet the welding quality requirements and reduce the waste of solder and welding time caused by the need to use more solder due to the small inclination angle of the side surface 145.

[0110] In some embodiments, the angle α2 between the side surface 145 and the first surface 131 is 75°, and the inclination angle of the side surface 145 is relatively large, which can meet the need of laser preheating of the side surface 145, especially the junction between the side surface 145 and the electrode terminal 1211, so that the melted solder can be better welded to the side surface 145 and the surface of the electrode terminal 1211.

[0111] By limiting the angle α2 between the side surface 145 and the first surface 131 to between 45° and 75°, the need for preheating the interface between the side surface 145 and the electrode terminal 1211 can be taken into account, while minimizing the waste of solder caused by the small inclination angle of the side surface 145 and the consumption of welding time, thereby improving the welding quality.

[0112] According to some embodiments of the present application, the hollow groove 140 includes a plurality of hollow sub-grooves 143 , which are arranged at intervals, and the connector 130 is connected to the same electrode terminal 1211 via solder filled in the plurality of hollow sub-grooves 143 .

[0113] like Figure 5 As shown, to meet the flow area requirement, a single, larger hollow groove 140 can be provided to connect to the electrode terminal 1211, or multiple hollow sub-grooves 143 can be provided to connect to the same electrode terminal 1211. Depending on the flow area requirement, the number of hollow sub-grooves 143 can be 2, 3, 5, etc. The hollow sub-grooves 143 can be, for example, linear, L-shaped, etc.

[0114] The plurality of hollow sub-grooves 143 are spaced apart from each other, and the spacing arrangement includes a uniform spacing arrangement and a non-uniform spacing arrangement. The extension directions of the plurality of hollow sub-grooves 143 may intersect or be parallel.

[0115] In some embodiments, the hollow groove 140 includes four hollow sub-grooves 143, and the four hollow sub-grooves 143 all extend in a straight line. The extension directions of the hollow sub-grooves 143 are parallel to each other. The connecting member 130 utilizes two hollow sub-grooves 143 to be welded to the same electrode terminal 1211, and the connecting member 130 can be welded to two electrode terminals 1211.

[0116] By connecting the connector 130 to the same electrode terminal 1211 using multiple hollow sub-grooves 143, multi-position welding can improve welding stability and welding quality compared to single-position welding while meeting the flow area.

[0117] According to some embodiments of the present application, the connector 130 further has a through hole 133 that penetrates the first surface 131 and the second surface 132 along the thickness direction, and the shortest distance between the through hole 133 and the hollow groove 140 is greater than or equal to 1 mm and less than or equal to 5 mm.

[0118] like Figure 6 As shown, through hole 133 is an observation hole used to detect welding quality. For example, a CCD (Charge Coupled Device) can be used to detect the gap between the second surface 132 of the connector 130 and the electrode terminal 1211, thereby determining the welding quality between the connector 130 and the electrode terminal 1211. Through hole 133 can be any shape, such as a round hole or a square hole.

[0119] The shortest distance L between the through hole 133 and the hollow groove 140 can be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, or a value between any two adjacent values ​​mentioned above.

[0120] If the shortest distance L between the through hole 133 and the hollow groove 140 is too small, the melted solder may penetrate into the through hole 133, affecting the accuracy of the inspection using the through hole 133. If the shortest distance L between the through hole 133 and the hollow groove 140 is too large and far away from the welding position, it will also reduce the accuracy of the welding quality inspection.

[0121] By limiting the shortest distance L between the through hole 133 and the hollow groove 140 to between 1 mm and 5 mm, the accuracy of detecting welding quality using the through hole 133 is improved, so that unqualified welding positions can be quickly screened.

[0122] According to some embodiments of the present application, the connector 130 further includes a first portion 134 and a second portion 135 connected to each other, the first portion 134 and the second portion 135 respectively having a hollow groove 140 , and the first portion 134 and the second portion 135 are respectively connected to the electrode terminals 1211 of different battery cells 120 through the hollow groove 140 .

[0123] Combine Figure 4 and Figure 5 As shown, the first portion 134 is a portion of the connector 130 and is used to connect to the electrode terminal 1211 of one battery cell 120 . Similarly, the second portion 135 is another portion of the connector 130 and is used to connect to the electrode terminal 1211 of another battery cell 120 .

[0124] The first portion 134 and the second portion 135 are respectively connected to the electrode terminals 1211 of different battery cells 120 , thereby achieving series connection or parallel connection between different battery cells 120 .

[0125] In some embodiments, the first portion 134 has a hollow groove 140 including two hollow sub-grooves 143. The first portion 134 is welded to the same electrode terminal 1211 through the two hollow sub-grooves 143. The second portion 135 also has a hollow groove 140 including two hollow sub-grooves 143. The second portion 135 is welded to another electrode terminal 1211 through the two hollow sub-grooves 143, thereby achieving current communication between the two battery cells 120.

[0126] The first portion 134 and the second portion 135 are connected to the electrode terminals 1211 of different battery cells 120 via the hollow grooves 140 , thereby enabling current communication between different battery cells 120 and further enabling current communication within the battery device 100 .

[0127] According to some embodiments of the present application, the connecting member 130 also includes an elastic connecting portion 136, which is used to connect the first portion 134 and the second portion 135. The elastic connecting portion 136 is constructed to be able to undergo elastic deformation when subjected to force to adjust the distance between the first portion 134 and the second portion 135.

[0128] like Figure 5 As shown, the elastic connecting portion 136 is located between the first portion 134 and the second portion 135 and is a structure that undergoes elastic deformation when subjected to force. The elastic connecting portion 136 adjusts the distance between the first portion 134 and the second portion 135 by elastic deformation.

[0129] The structure of the elastic connection portion 136 is not limited, and can be, for example, a hollow structure, a bent structure, etc. that is more susceptible to elastic deformation.

[0130] In some embodiments, first portion 134 is welded to the electrode terminal of one battery cell, and second portion 135 is welded to the electrode terminal of another adjacent battery cell. During operation, a battery cell may expand, increasing the distance between the electrode terminals of two adjacent battery cells. The elastic connection portion 136 elastically deforms, generating elastic tension and correspondingly increasing the distance between the first portion 134 and the second portion 135. When the battery cell returns to its original state, the elastic connection portion 136 also returns to its original state under the action of the elastic tension, restoring the original distance between the first portion 134 and the second portion 135.

[0131] By utilizing the design of the elastic connecting portion 136, the distance between the first portion 134 and the second portion 135 can be appropriately adjusted according to actual needs, reducing the risk of cracking between the electrode terminal 1211 and the connector 130 due to changes in the structural state of the battery cell 120, and improving the stability of the connection.

[0132] According to some embodiments of the present application, the elastic connection portion 136 includes at least one through hole 1361 penetrating along the thickness direction.

[0133] like Figure 5 As shown, in some embodiments, the elastic connection portion 136 includes a via hole 1361 extending through the thickness direction. The elastic connection portion 136 where the via hole 1361 is located forms a structurally weak area. When the first portion 134 and the second portion 135 are subjected to opposite forces, the structurally weak area is susceptible to elastic deformation. The structural shape of the via hole 1361 is not limited, for example, a strip-shaped via hole, a circular via hole, etc. The number of via holes 1361 is not limited, for example, 1, 2, 3, etc.

[0134] By adopting the through hole 1361 design for the elastic connecting portion 136 , the structure is simple and the manufacturing is convenient, which facilitates the rapid mass production of the connecting member 130 .

[0135] According to some embodiments of the present application, the battery device 100 further includes a battery cell assembly and an integrated busbar. The battery cell assembly includes a plurality of battery cells 120 arranged along a first direction and end plates that clamp the plurality of battery cells 120. The integrated busbar includes a body and a plurality of connectors 130 connected to the body. The body is connected to the end plates, and the plurality of battery cells 120 are connected in series via the connectors 130. In some embodiments, the battery device 100 further includes a battery cell assembly and an integrated busbar. The battery cell assembly includes a plurality of battery cells 120 arranged along a first direction and end plates that clamp the plurality of battery cells 120. The integrated busbar includes a body and a plurality of connectors 130 connected to the body. The body is connected to the end plates, and the plurality of battery cells 120 are connected in parallel via the connectors 130.

[0136] The integrated busbar includes a flexible circuit board, a connector 130 and other structures.

[0137] The multiple connectors 130 are respectively connected to the body of the integrated busbar, which can be understood as the multiple connectors 130 being connected to the frame structure of the integrated busbar.

[0138] like Figure 4 As shown, multiple connectors 130 are mounted and fixed to the frame structure of the integrated busbar. The integrated busbar connects the overall structure including the multiple connectors 130 to the end plates of the battery cell assembly. The two end plates are arranged opposite each other along a first direction X. Between the two end plates are multiple battery cells 120 arranged along the first direction X. The multiple connectors 130 correspond to the electrode terminals 1211 of different battery cells 120. There is no need to adjust the position of each connector 130. Direct welding is performed, allowing the multiple battery cells 120 to be connected in series, in parallel, or in a combination of series and parallel via the connectors 130. This structure can improve welding efficiency.

[0139] By connecting multiple connectors 130 to the integrated busbar and utilizing the connection between the integrated busbar and the end plate to achieve positioning of the multiple connectors 130 , time for adjusting the connectors 130 individually can be saved, while also improving welding quality.

[0140] According to some embodiments of the present application, the connector 130 has a positioning hole 137 , and the body has a positioning boss. The positioning hole 137 is configured to cooperate with the positioning boss to limit and fix the connector 130 .

[0141] The main body has a positioning boss, which means that the positioning boss is set on the frame structure of the integrated busbar, and the positioning boss is used to cooperate with the positioning hole 137 to limit and fix the connecting member 130.

[0142] It should be noted that the positioning boss and the positioning hole 137 are structures used to achieve a quick and fixed connection between the connector 130 and the frame structure of the integrated busbar. There is no limit to their position setting, and they should meet the requirement that after the integrated busbar is connected to the end plate, the hollow groove 140 of the connector 130 should correspond to the electrode terminal 1211.

[0143] By utilizing the positioning holes 137 in conjunction with the positioning bosses to achieve rapid fixation of the plurality of connectors 130 , assembly time can be saved and assembly efficiency can be improved.

[0144] An embodiment of the present application provides an electrical device, including the battery device 100 in any of the above embodiments, and the battery device 100 is used to provide electrical energy.

[0145] An embodiment of the present application provides an energy storage device, including the battery device 100 in any of the above embodiments, and the energy storage device is used to store electrical energy.

[0146] Combine Figures 3 to 10 As shown, the present application is further described below in conjunction with a specific embodiment.

[0147] The battery device 100 includes a plurality of battery cells 120 and a plurality of connectors 130 .

[0148] The battery cell 120 includes an end cap 121 and a housing 122 . The housing 122 has an opening for accommodating the electrode assembly 123 . The end cap 121 covers the opening of the housing 122 to seal the accommodating cavity. Electrode terminals 1211 are provided on the end cap 121 .

[0149] The connecting member 130 includes a first surface 131 and a second surface 132 disposed opposite to each other along the thickness direction, and the second surface 132 faces the electrode terminal 1211 .

[0150] The connector 130 includes a first portion 134, a second portion 135, and an elastic connector 136 connecting the first portion 134 and the second portion 135. The elastic connector 136 includes a through hole 1361 extending through the thickness direction. The elastic connector 136 elastically deforms when subjected to force to adjust the distance between the first portion 134 and the second portion 135.

[0151] The first portion 134 and the second portion 135 respectively have a hollow groove 140 configured to accommodate solder. The first portion 134 and the second portion 135 are respectively connected to the electrode terminals 1211 of different battery cells 120 through the solder filled in the hollow groove 140 .

[0152] Among them, the hollow groove 140 includes a first opening 141 passing through the first surface 131 and a second opening 142 passing through the second surface 132, the orthographic projection of the second opening 142 on the first surface 131 completely falls within the range of the first opening 141, and the orthographic projection area of ​​the second opening 142 on the first surface 131 is smaller than the area of ​​the first opening 141.

[0153] At the same time, in a plane perpendicular to the thickness direction of the connecting member 130 , the orthographic projection of the second opening 142 completely falls within the orthographic projection range of the electrode terminal 1211 .

[0154] The hollow groove 140 also includes two end surfaces 144 arranged along the extension direction and two side surfaces 145 arranged perpendicular to the extension direction. The two end surfaces 144 are spaced apart from each other in a direction that points from the second surface 132 to the first surface 131. The two side surfaces 145 are spaced apart from each other in a direction that is perpendicular to the extension direction. The angle α1 between the end surfaces 144 and the first surface 131 and the angle α2 between the side surfaces 145 and the first surface 131 satisfy the following conditions: α1 ≤ α2.

[0155] The connection member 130 further has a through hole 133 that penetrates the first surface 131 and the second surface 132 along the thickness direction. The through hole 133 is used to detect the gap between the second surface 132 of the connection member 130 and the electrode terminal 1211 .

[0156] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery device, characterized in that: include: a battery cell, including electrode terminals; a connecting member comprising a first surface and a second surface disposed opposite to each other in a thickness direction, the second surface facing the electrode terminal; the connecting member further comprising a hollow groove extending through the thickness direction, the hollow groove being configured to accommodate a solder, and the connecting member and the electrode terminal being connected via the solder filled in the hollow groove; In which, the hollow groove includes a first opening passing through the first surface and a second opening passing through the second surface, the orthographic projection of the second opening on the first surface completely falls within the range of the first opening, and the orthographic projection area of ​​the second opening on the first surface is smaller than the area of ​​the first opening.

2. The battery device according to claim 1, wherein: Along the direction from the second surface to the first surface, the cross-sectional area of ​​the hollow groove gradually increases.

3. The battery device according to claim 1, wherein: In a plane perpendicular to the thickness direction of the connecting member, the orthographic projection of the second opening completely falls within the orthographic projection range of the electrode terminal.

4. The battery device according to any one of claims 1 to 3, characterized in that: The hollow groove includes two end surfaces arranged along the extension direction, and the distance between the two end surfaces gradually increases along the direction from the second surface to the first surface.

5. The battery device according to claim 4, characterized in that The hollow groove further includes two side surfaces arranged perpendicular to the extending direction, and the spacing between the two side surfaces increases gradually in a direction perpendicular to the extending direction, along the direction from the second surface to the first surface.

6. The battery device according to claim 5, characterized in that An included angle α1 between the end face and the first surface and an included angle α2 between the side face and the first surface satisfy α1≤α2.

7. The battery device according to claim 6, characterized in that An included angle α1 between the end face and the first surface satisfies 30°≤α1≤60°.

8. The battery device according to claim 7, characterized in that An included angle α2 between the side surface and the first surface satisfies 45°≤α2≤75°.

9. The battery device according to any one of claims 1 to 3, characterized in that: The hollow groove includes a plurality of hollow sub-grooves, the plurality of hollow sub-grooves are arranged at intervals, and the connecting member is connected to the same electrode terminal through the solder filled in the plurality of hollow sub-grooves.

10. The battery device according to any one of claims 1 to 3, characterized in that: The connecting member further has a through hole penetrating the first surface and the second surface along the thickness direction, and the shortest distance between the through hole and the hollow groove is greater than or equal to 1 mm and less than or equal to 5 mm.

11. The battery device according to any one of claims 1 to 3, characterized in that: The connector further includes a first portion and a second portion connected to each other, wherein the first portion and the second portion respectively have the hollow groove, and the first portion and the second portion are respectively connected to electrode terminals of different battery cells through the hollow groove.

12. The battery device according to claim 11, wherein: The connecting member further includes an elastic connecting portion, which is used to connect the first portion and the second portion. The elastic connecting portion is configured to be elastically deformed when subjected to force to adjust the distance between the first portion and the second portion.

13. The battery device according to claim 12, wherein: The elastic connecting portion includes at least one through hole penetrating along the thickness direction.

14. The battery device according to any one of claims 1 to 3, characterized in that: The battery device further comprises: A battery cell assembly, comprising a plurality of battery cells arranged along a first direction and end plates for clamping the plurality of battery cells; An integrated busbar comprises a main body and a plurality of connecting members connected to the main body; The main body is connected to the end plate, and a plurality of battery cells are connected in series and / or in parallel via the connector.

15. The battery device according to claim 14, characterized in that The connecting member has a positioning hole, and the main body has a positioning boss. The positioning hole is configured to cooperate with the positioning boss to limit and fix the connecting member.

16. An electrical device, characterized in that: The electrical device comprises the battery device according to any one of claims 1 to 15, and the battery device is used to provide electrical energy.

17. An energy storage device, characterized in that: The energy storage device comprises the battery device according to any one of claims 1 to 15, and the energy storage device is used to store electrical energy.

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