Battery monomer, battery device and electric device

Abstract

The utility model discloses a battery monomer, a battery device and a power utilization device. The battery cell includes a housing, an electrode assembly, and a current collector. The shell comprises a wall part; the electrode assembly is accommodated in the housing, and one side, facing the wall part, of the electrode assembly is provided with a first tab. The current collector is arranged between the first tab and the wall part and comprises a first connecting part, a second connecting part and a fusing part; the first connecting part is connected to the wall part and is spaced from the first tab; the second connecting part surrounds the first connecting part, is connected to the first tab and is spaced from the wall part; the fusing part is connected with the first connecting part and the second connecting part, and the fusing part, the first tab and the wall part are arranged at intervals. When internal short circuit occurs in the single battery, the fusing part can be fused under the action of instantaneous high temperature, so that a current loop in the single battery is disconnected, a short-circuit protection effect is achieved, potential safety hazards such as fire and explosion caused by short circuit of the single battery are reduced, and the reliability of the single battery is improved.

Description

Technical Field

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

[0002] Batteries are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes and power tools, etc.

[0003] Short-circuit safety protection of batteries during actual application is an important part of battery design. Utility Model Content

[0004] The embodiments of the present application provide a battery cell, a battery device, and an electrical device, which can reduce safety hazards such as fire and explosion caused by short circuits in battery cells and improve the reliability of battery cells.

[0005] According to the first aspect of the present application, the present application provides a battery cell, which includes a shell, an electrode assembly and a current collector. The shell includes a wall portion; the electrode assembly is accommodated in the shell, and the electrode assembly has a first pole lug on the side facing the wall portion. The current collector is arranged between the first pole lug and the wall portion, and the current collector includes a first connecting portion, a second connecting portion and a fuse portion; the first connecting portion is connected to the wall portion and is spaced apart from the first pole lug; the second connecting portion surrounds the first connecting portion, the second connecting portion is connected to the first pole lug and is spaced apart from the wall portion; the fuse portion connects the first connecting portion and the second connecting portion, and the fuse portion is spaced apart from both the first pole lug and the wall portion. When an internal short circuit occurs in the battery cell, the fuse portion can be melted under the action of instantaneous high temperature, thereby disconnecting the current loop inside the battery cell, playing a short circuit protection role, which is conducive to reducing safety hazards such as fire and explosion caused by short circuit in the battery cell, and improving the reliability of the battery cell.

[0006] In some embodiments, at least a portion of the first connecting portion protrudes from the second connecting portion toward the wall portion and abuts against the wall portion; the second connecting portion and the wall portion are spaced apart along the thickness direction of the wall portion, which is conducive to achieving insulation isolation between the second connecting portion and the wall portion, preventing the current of the second connecting portion from flowing directly to the wall portion, and is conducive to the fuse portion melting in time when an internal short circuit occurs in the battery cell.

[0007] In some embodiments, the fuse is spaced apart from the wall along the thickness direction; the battery cell includes a first insulating member disposed between the fuse and the wall. The first insulating member further insulates the fuse from the wall. After the fuse blows, the first insulating member insulates the wall from the first tab, reducing the possibility of overlap between the wall and the first tab and improving the effectiveness of short-circuit protection.

[0008] In some embodiments, the first connecting portion includes a first side surface facing the first insulating member, and the fusible portion includes a first surface facing the wall portion; the first insulating member covers the first side surface and the first surface. After the fusible portion melts, the first insulating member can separate the disconnection space formed by the melting of the fusible portion from the wall portion along the thickness direction, thereby reducing the possibility of overlap between the wall portion and the first tab and improving the effectiveness of short-circuit protection.

[0009] In some embodiments, the first side surface includes a first surface and a second surface, the first surface and the second surface being arranged along the thickness direction and staggered in a direction perpendicular to the thickness direction. This facilitates forming the first insulating member by encapsulating the first insulating member between the fuse portion and the wall portion, reducing the possibility of the first insulating member separating from the first side surface and the first surface, and improving the stability and insulation isolation effect of the first insulating member.

[0010] In some embodiments, the battery cell includes a second insulating member disposed between the second connecting portion and the wall portion. The second insulating member can support the second connecting portion, thereby indirectly supporting the electrode assembly. The force exerted by the electrode assembly on the current collector can be transmitted to the wall portion via the second insulating member, reducing the risk of deformation of the second connecting portion and improving the reliability of the connection between the second connecting portion and the first tab.

[0011] In some embodiments, the second connecting portion includes a second surface facing the wall portion, and the first connecting portion includes a third surface facing the electrode assembly, with the second and third surfaces being flush with each other. Along the thickness direction, the thickness of the second insulating member is the same as that of the first connecting portion. This allows the second insulating member's two opposing surfaces along the thickness direction to abut against the second connecting portion and the wall portion, respectively, thereby improving the second insulating member's support for the second connecting portion and reducing the likelihood of displacement of the second insulating member.

[0012] In some embodiments, the second connecting portion includes a fourth surface facing the first tab, and a first recess is provided on a side of the current collector facing the first tab, the first recess being recessed into the fourth surface. In the thickness direction of the wall portion, the projection of the first connecting portion is located within the projection of the first recess. The first connecting portion may be separated from the first tab by at least a portion of the interior space of the first recess, thereby facilitating the prevention of current flow between the first connecting portion and the first tab.

[0013] In some embodiments, the surface of the fuse portion facing the electrode assembly forms a stepped surface of the first recess, and at least a portion of the surface of the first connecting portion facing the electrode assembly forms the bottom surface of the first recess, with the bottom surface being closer to the wall than the stepped surface, and the stepped surface being closer to the wall than the fourth surface; the first surface of the fuse portion facing the wall is flush with the bottom surface. The provision of the first recess facilitates isolation of the fuse portion from the first tab, and isolation of the first connecting portion from the first tab, with a simple structure and process.

[0014] In some embodiments, the fuse is spaced apart from the first tab along the thickness direction; the battery cell includes a third insulating member, at least a portion of which is positioned between the fuse and the first tab. After the fuse blows, the third insulating member can insulate the wall from the first tab, reducing the possibility of overlap between the wall and the first tab and improving the effectiveness of short-circuit protection.

[0015] In some embodiments, the third insulating member covers at least the surface of the fuse portion facing the electrode assembly and the second side surface of the fuse portion facing away from the second connecting portion. After the fuse portion blows, the third insulating member can separate the disconnected space formed by the melting of the fuse portion from the first tab along the thickness direction, thereby reducing the possibility of overlap between the wall portion and the first tab and improving the effectiveness of short-circuit protection.

[0016] In some embodiments, the second connection portion surrounds the fuse portion, and the fuse portion and the first connection portion partially overlap in the thickness direction of the wall portion, which is beneficial to reducing the risk of breakage at the connection position between the fuse portion and the first connection portion and improving the overall structural strength of the current collector.

[0017] In some embodiments, the thickness of the fuse portion is smaller than that of the first connecting portion and the second connecting portion. When the same current flows through the first connecting portion, the second connecting portion, and the fuse portion, the fuse portion, due to its smaller thickness, has a greater resistance to the current, generates more heat, and is more likely to melt.

[0018] In some embodiments, the thickness of the fuse portion is 0.1mm to 0.3mm, which can balance the capacity of the battery cell and the short-circuit protection effect of the fuse portion, and can achieve a balance between the flow capacity of the first connection portion and the energy density of the battery cell, and can also effectively separate the first connection portion from the first pole ear, thereby improving the effectiveness of short-circuit protection; and / or, the thickness of the first connection portion is 0.3mm to 0.5mm; and / or, the thickness of the second connection portion is 0.3mm to 0.5mm, which can achieve a balance between the flow capacity of the second connection portion and the energy density of the battery cell, and can also effectively separate the second connection portion from the wall portion, thereby improving the effectiveness of short-circuit protection.

[0019] In some embodiments, the wall portion is provided with a first through-hole, and the current collector is provided with a second through-hole, the second through-hole communicating with the first through-hole and the interior space of the housing. The battery cell includes a sealing plate, located on the side of the wall portion facing away from the electrode assembly, connected to the wall portion, and sealing the first through-hole. The first through-hole can serve as a liquid injection port for the battery cell, and the sealing plate can prevent liquid leakage. The first through-hole can also serve as a pressure relief port for the battery cell, allowing pressure relief material to be discharged through the first through-hole to achieve the purpose of pressure relief.

[0020] In some embodiments, a second recess is provided on the side of the wall facing away from the electrode assembly, and the sealing plate is entirely accommodated in the second recess. The second recess provides space for the sealing plate, and the sealing plate and the wall share a portion of the space along the thickness direction, which is conducive to improving space utilization and energy density.

[0021] In some embodiments, the interior space of the second recess includes a first portion and a second portion, the first portion and the second portion being arranged along the thickness direction of the wall portion, with the first portion being closer to the electrode assembly than the second portion, and the second portion extending beyond the first portion in a direction perpendicular to the thickness direction. The sealing plate is disposed within the first portion and welded to the wall portion. The portion of the second portion extending beyond the first portion can provide space for the molten pool after welding the sealing plate to the wall portion, reducing the extent of the molten pool protruding along the thickness direction, thereby reducing the possibility of the molten pool extending beyond the wall portion after welding the sealing plate to the wall portion, and thus improving the appearance of the battery cell.

[0022] In some embodiments, the wall portion includes a third connecting portion, which corresponds to at least a portion of the second recess along the thickness direction, and the first through hole is provided in the third connecting portion; the first connecting portion is connected to the third connecting portion, and the thickness of the third connecting portion is 0.3 mm to 0.5 mm, which neither takes up a large space nor affects the depth of the second recess, and is conducive to improving its structural strength and flow capacity.

[0023] In some embodiments, the sealing plate includes a main portion and a protrusion. The protrusion surrounds the main portion and protrudes from the main portion toward the electrode assembly. The protrusion is connected to the wall portion, and the main portion and the wall portion are spaced apart. Along the thickness direction of the wall portion, the projection of the first through hole is located within the projection of the main portion. A gap is formed between the main portion and the wall portion, and the first through hole can be connected to this gap. When the battery cell releases pressure, this gap can form a vent space, through which the pressure-releasing material can impact the sealing plate, facilitating the successful pressure release through the sealing plate.

[0024] In some embodiments, the main body has a weak portion, and the thickness of the weak portion is smaller than the thickness of other parts of the main body except the weak portion. When subjected to the same impact, the weak portion is more likely to break, which is conducive to timely pressure relief of the sealing plate.

[0025] In some embodiments, the housing includes a shell and an end cover, the shell includes an integrally formed side wall and end wall, the side wall surrounds the electrode assembly, the end wall and the end cover are opposite along the thickness direction of the wall portion, and the end cover is sealed to the side wall; the wall portion is the end wall.

[0026] In some embodiments, the battery cell includes an electrode terminal, which is located on a side of the end cap facing away from the electrode assembly; the electrode assembly includes a second tab, which has an opposite polarity to the first tab and is connected to the electrode terminal.

[0027] In some embodiments, the battery cells are cylindrical battery cells.

[0028] According to a second aspect of the present application, an embodiment of the present application provides a battery device, and an electrical device includes a plurality of battery cells provided according to any embodiment of the present application.

[0029] According to a third aspect of the present application, an embodiment of the present application provides an electrical device, which includes a battery device provided by any embodiment of the present application, and the battery device is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 It is a schematic structural diagram of a vehicle provided in some embodiments of the present application.

[0032] Figure 2 It is a schematic diagram of the exploded structure of the battery device provided in some embodiments of the present application.

[0033] Figure 3 yes Figure 2 Schematic diagram of the exploded structure of the battery cell assembly of the battery device shown.

[0034] Figure 4 This is a schematic diagram of the exploded structure of a battery cell provided in some embodiments of the present application.

[0035] Figure 5 yes Figure 4 Schematic diagram of the cross-sectional structure of the battery cell shown.

[0036] Figure 6 yes Figure 5 Schematic diagram of the enlarged structure of area A in the middle.

[0037] Figure 7 yes Figure 5 Schematic diagram of the decomposition structure.

[0038] Figure 8 yes Figure 7 Schematic diagram of the enlarged structure of area B in the middle.

[0039] Figure 9 yes Figure 5 Schematic diagram of the structure of the current collecting member of the battery cell shown.

[0040] Figure 10 yes Figure 9 Schematic diagram of the cross-sectional structure of the current collecting component shown.

[0041] Figure 11 yes Figure 10 Schematic diagram of the enlarged structure of area C in FIG.

[0042] In the attached figure:

[0043] Vehicle 1, battery device 2, controller 3, motor 4, housing 5, battery cell assembly 6, battery cell 7;

[0044] Housing 10, wall 11, first through hole 111, second recess 112, first portion 1121, second portion 1122, sixth surface 113, third connection portion 114, housing 12, side wall 121, end wall 122, end cap 13, electrode assembly 20, first tab 21, second tab 22, electrode body 23, current collector 30, first connection portion 31, first side surface 311, first surface 3111, second surface 3112, third surface 312 , second connecting portion 32, second surface 321, fourth surface 322, fuse portion 33, first surface 331, second side surface 332, first recess 34, step surface 341, bottom surface 342, second through hole 35, first insulating member 40, second insulating member 50, first box body portion 5a, second box body portion 5b, third insulating member 60, sealing plate 70, fifth surface 71, main body portion 72, protrusion 73, weak portion 74, electrode terminal 80, thickness direction X. DETAILED DESCRIPTION

[0045] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0046] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application 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 the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0047] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the 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.

[0048] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0049] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0050] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0051] The term "plurality" used in this application refers to two or more (including two).

[0052] In the embodiments of the present application, "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; at the same time, "vertical" includes not only the absolutely vertical situation, but also the roughly vertical situation conventionally recognized in engineering.

[0053] In the embodiment of the present application, the battery cell may be 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.

[0054] The battery cell 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.

[0055] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell or a battery cell of other shapes. The prismatic battery cell includes a square shell battery cell, a blade-shaped battery cell, a polygonal battery, such as a hexagonal battery, etc. There is no special limitation in this application.

[0056] The battery device mentioned in the embodiments of the present application includes one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells, which are connected in series, parallel or hybrid via a busbar.

[0057] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells. For example, the battery cell assembly may be a battery module, which is formed by arranging and securing multiple battery cells to form a single module. For example, a battery module may be formed by bundling multiple battery cells using cable ties.

[0058] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0059] As an example, the battery cell assembly may also be housed in the box by directly fixing the plurality of battery cells to the box.

[0060] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0061] In some embodiments, the battery device may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0062] A battery cell typically includes an electrode assembly and a housing for housing the electrode assembly. The electrode assembly typically includes a positive electrode tab and a negative electrode tab, each of which is connected to two electrode terminals on the housing.

[0063] Currently, some battery cells with single-ended terminals and live outer casings are available on the market. The outer casing serves as one of the electrodes in the battery cell, and the positive and negative tabs of the electrode assembly are connected to the terminal and outer casing, respectively, through components such as current collector plates. The tabs connecting to the terminal and the outer casing may overlap due to the presence of metal wires, conductive particles, etc., leading to the risk of short circuits, which can cause the battery cell to catch fire or explode in severe cases.

[0064] In view of this, an embodiment of the present application provides a technical solution, which provides a fuse part on the current collecting part used to connect the first pole ear and the outer shell. When an internal short circuit occurs in the battery cell, the fuse part melts under the high temperature caused by the large current, thereby disconnecting the connection between the first pole ear and the outer shell, which is beneficial to reducing safety hazards such as fire and explosion caused by short circuit in the battery cell and improving the reliability of the battery cell.

[0065] The technical solutions provided in the embodiments of this application are applicable to battery cells, battery devices, and electrical devices using battery devices. Electrical devices may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and power tools. Vehicles may include fuel-powered vehicles, gas-powered vehicles, or new energy vehicles. New energy vehicles may include pure electric vehicles, hybrid vehicles, or extended-range vehicles. Spacecraft include aircraft, rockets, space shuttles, and spacecraft. The embodiments of this application do not impose any specific restrictions on these electrical devices.

[0066] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0067] Figure 1 Schematic diagram of the structure of the vehicle provided by some embodiments of the present application. Figure 1 Vehicle 1 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. A battery device 2 is provided inside vehicle 1. Battery device 2 can be located at the bottom, head, or tail of vehicle 1. Battery device 2 can be used to power vehicle 1. For example, battery device 2 can serve as an operating power source for vehicle 1. Vehicle 1 can also include a controller 3 and a motor 4. Controller 3 is used to control battery device 2 to power motor 4, for example, to meet the power requirements of vehicle 1 during startup, navigation, and driving.

[0068] In some embodiments of the present application, the battery device 2 can serve not only as an operating power source for the vehicle 1 , but also as a driving power source for the vehicle 1 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1 .

[0069] Figure 2 Schematic diagram of the exploded structure of the battery device provided in some embodiments of the present application. Figure 2 The battery device 2 includes a box 5 and a battery cell ( Figure 2(not shown), the battery cells are accommodated in the box body 5. The box body 5 is used to provide a storage space for the battery cells, and the box body 5 can adopt a variety of structures. In some embodiments, the box body 5 may include a first box body portion 5a and a second box body portion 5b, the first box body portion 5a and the second box body portion 5b cover each other, and the first box body portion 5a and the second box body portion 5b jointly define a storage space for accommodating the battery cells. The second box body portion 5b can be a hollow structure with one end open, and the first box body portion 5a can be a plate-like structure, and the first box body portion 5a covers the open side of the second box body portion 5b, so that the first box body portion 5a and the second box body portion 5b jointly define a storage space; the first box body portion 5a and the second box body portion 5b can also be hollow structures with one side open, and the open side of the first box body portion 5a covers the open side of the second box body portion 5b. Of course, the box body 5 formed by the first box body portion 5a and the second box body portion 5b can be a variety of shapes, such as a cylinder, a cuboid, etc.

[0070] A battery cell may be the smallest unit constituting a battery.

[0071] The battery device 2 may include multiple battery cells, which may be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections. Multiple battery cells may be directly connected in series, in parallel, or in a hybrid configuration, and then the entire assembly of multiple battery cells is housed within the housing 5. Alternatively, the battery device 2 may include multiple battery cells connected in series, in parallel, or in a hybrid configuration to form a battery cell assembly 6, which is then connected in series, in parallel, or in a hybrid configuration to form a single assembly, which is then housed within the housing 5. The battery device 2 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells.

[0072] Each battery cell can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell can be cylindrical, flat, rectangular, or in other shapes.

[0073] Figure 3 yes Figure 2 Schematic diagram of the exploded structure of a battery cell assembly of a battery device shown. In some embodiments, a battery cell assembly 6 includes multiple battery cells 7. The multiple battery cells 7 are first connected in series, parallel, or in parallel to form a battery cell assembly 6, and then the multiple battery cell assemblies 6 are connected in series, parallel, or in parallel to form a complete assembly. The multiple battery cells 7 in a battery cell assembly 6 can be electrically connected via a busbar assembly to enable parallel, series, or parallel connection of the multiple cylindrical battery cells 7 in the battery cell assembly 6. There can be one or more busbars, each of which is used to electrically connect at least two battery cells 7.

[0074] Figure 4is a schematic diagram of the exploded structure of a battery cell provided in some embodiments of the present application, Figure 5 yes Figure 4 The cross-sectional structure diagram of the battery cell shown. Figure 4 and Figure 5 The battery cell 7 provided in the embodiment of the present application includes a housing 10 and an electrode assembly 20 , and the electrode assembly 20 is accommodated in the housing 10 .

[0075] The housing 10 is a hollow structure, and a space is formed inside the housing 10 for accommodating the electrode assembly 20 and the electrolyte. The shape of the housing 10 can be cylindrical, prismatic, rectangular or other shapes.

[0076] Optionally, the housing 10 may include a shell 12 and an end cap 13 , which may be separate components. The shell 12 has an opening, and the end cap 13 covers the opening of the shell 12 .

[0077] The housing 12 may be open at one end or at both ends. For example, the housing 12 is open at one end, and one end cap 13 is provided to cover the opening of the housing 12. As another example, the housing 12 may be open at both ends, and two end caps 13 are provided, each of which covers the two openings of the housing 12.

[0078] The shell 12 may include a plurality of shell walls, and the end cover 13 and the plurality of shell walls of the shell 12 together enclose an inner space of the outer shell 10 .

[0079] The shell 12 may be made of various materials, such as copper, iron, aluminum, aluminum alloy, etc. The material of the end cover 13 may be the same as or different from that of the shell 12 .

[0080] The electrode assembly 20 is a component in the battery cell 7 where electrochemical reactions occur.

[0081] The electrode assembly 20 may include a first electrode tab 21, a second electrode tab 22, and an electrode body 23. One of the first electrode tab 21 and the second electrode tab 22 is an anode electrode tab, and the other is a cathode electrode tab. The first electrode tab 21 and the second electrode tab 22 may be extended from opposite ends of the electrode body 23 and connected to the two electrode terminals of the battery cell 7.

[0082] Figure 6 yes Figure 5 Schematic diagram of the enlarged structure of area A in the middle. Figure 7 yes Figure 5 Schematic diagram of the decomposition structure, Figure 8 yes Figure 7 In some embodiments, referring to Figures 5 to 8 The battery cell 7 includes a housing 10 , an electrode assembly 20 and a current collector 30 .

[0083] Figure 9 yes Figure 5 The schematic diagram of the structure of the current collector of the battery cell shown in FIG. Figure 10 yes Figure 9 The cross-sectional structure diagram of the current collecting member is shown in FIG. Figure 11 yes Figure 10 Schematic diagram of the enlarged structure of area C in FIG.

[0084] Reference Figures 5 to 11 The housing 10 includes a wall portion 11. The electrode assembly 20 is accommodated in the housing 10, and the electrode assembly 20 has a first electrode tab 21 on the side facing the wall portion 11. The current collector 30 is arranged between the first electrode tab 21 and the wall portion 11. The current collector 30 includes a first connecting portion 31, a second connecting portion 32 and a fuse portion 33. The first connecting portion 31 is connected to the wall portion 11 and is spaced apart from the first electrode tab 21. The second connecting portion 32 surrounds the first connecting portion 31. The second connecting portion 32 is connected to the first electrode tab 21 and is spaced apart from the wall portion 11. The fuse portion 33 connects the first connecting portion 31 and the second connecting portion 32. The fuse portion 33 is spaced apart from both the first electrode tab 21 and the wall portion 11.

[0085] Optionally, the wall portion 11 may be one of the walls of the housing 12 , or may be the end cover 13 .

[0086] The electrode assembly 20 is a component where electrochemical reactions occur in the battery cell 7. The first electrode tab 21 can be led out from one end of the electrode body 23 facing the wall portion 11.

[0087] Exemplarily, the second connection portion 32 surrounds the fuse portion 33, and the fuse portion 33 surrounds the first connection portion 31. The fuse portion 33 connects the inner periphery of the second connection portion 32 near the fuse portion 33 and the outer periphery of the first connection portion 31 near the fuse portion 33. Along the thickness direction X of the wall portion 11, the projection of the second connection portion 32, the projection of the fuse portion 33, and the projection of the first connection portion 31 do not overlap with each other.

[0088] As another example, along the thickness direction X of the wall portion 11 , the projection of the second connection portion 32 may partially overlap with the projection of the fuse portion 33 , and the projection of the fuse portion 33 may partially overlap with the projection of the first connection portion 31 .

[0089] The first connection portion 31 is electrically connected to the wall portion 11 . The first connection portion 31 may be directly connected to the wall portion 11 or indirectly connected to the wall portion 11 through other components.

[0090] The second connecting portion 32 is electrically connected to the first electrode tab 21 . The second connecting portion 32 may be directly connected to the first electrode tab 21 or indirectly connected to the first electrode tab 21 through other components.

[0091] The first connecting portion 31 and the first electrode tab 21, the second connecting portion 32 and the wall portion 11, the fuse portion 33 and the first electrode tab 21, and the fuse portion 33 and the wall portion 11 can all be separated by gap spaces or insulating members, as long as the two separated components are not electrically connected.

[0092] The first connection portion 31 , the second connection portion 32 and the fuse portion 33 may be an integrally formed structure.

[0093] The first electrode tab 21 is connected to the wall portion 11 through the current collecting member 30 . The wall portion 11 forms one of the electrodes of the battery cell 7 , thereby eliminating a traditional electrode terminal, simplifying the structure, and saving space.

[0094] The first electrode tab 21 and the wall portion 11 are electrically connected via the current collector 30. The current output by the first electrode tab 21 flows sequentially through the second connecting portion 32, the fuse portion 33, and the first connecting portion 31 to the wall portion 11. When the same current flows, the heat generated by the fuse portion 33 is greater than that generated by the first connecting portion 31 and the second connecting portion 32, and the fuse portion 33 is more likely to be melted than the first connecting portion 31 and the second connecting portion 32.

[0095] Optionally, the current flow area of the fuse portion 33 may be smaller than the current flow area of the first connection portion 31 and the current flow area of the second connection portion 32 .

[0096] For example, the fuse part 33 may be formed by thinning a portion of the current collecting member 30 , or a through hole, groove or other structure may be provided in the fuse part 33 to reduce the area of the fuse part 33 through which current can flow.

[0097] When an internal short circuit occurs in the battery cell 7, for example, when the second pole ear 22 is overlapped with the wall portion 11 through metal wire, conductive particles, etc., the fuse portion 33 can be melted under the action of instantaneous high temperature, thereby disconnecting the current loop inside the battery cell 7, playing a short circuit protection role, which is beneficial to reduce the safety hazards such as fire and explosion caused by short circuit of the battery cell 7, and improve the reliability of the battery cell 7.

[0098] In some embodiments, at least a portion of the first connection portion 31 protrudes from the second connection portion 32 toward the wall 11 and abuts against the wall 11. The second connection portion 32 and the wall 11 are spaced apart along the thickness direction X of the wall 11.

[0099] For example, the entire first connection portion 31 may protrude from the second connection portion 32 in a direction close to the wall portion 11. As another example, only a portion of the first connection portion 31 may protrude from the second connection portion 32 in a direction close to the wall portion 11, and the other portion of the first connection portion 31 and the second connection portion 32 may overlap in a direction perpendicular to the thickness direction X.

[0100] The portion of the first connection portion 31 protruding from the second connection portion 32 can prop up the second connection portion 32 so that the second connection portion 32 is suspended on the side of the wall portion 11 facing the electrode assembly 20 , which is conducive to separating the second connection portion 32 from the wall portion 11 along the thickness direction X.

[0101] The first connecting portion 31 realizes electrical connection between the two by directly abutting against the wall portion 11, which is beneficial to increase the contact area between the two and improve the flow capacity. It can also support the current collecting member 30 through the wall portion 11, which is beneficial to simplify the structure and assembly process and improve structural stability.

[0102] The second connection portion 32 is spaced apart from the wall portion 11 along the thickness direction X, which is conducive to achieving insulation isolation between the second connection portion 32 and the wall portion 11, preventing the current of the second connection portion 32 from flowing directly to the wall portion 11, and facilitating the fuse portion 33 to melt in time when an internal short circuit occurs in the battery cell 7.

[0103] In some embodiments, the fuse portion 33 is spaced apart from the wall portion 11 along the thickness direction X. The battery cell 7 includes a first insulating member 40 , which is disposed between the fuse portion 33 and the wall portion 11 .

[0104] A gap space may be formed between the fuse portion 33 and the wall portion 11 , and the first insulating member 40 may be disposed in the gap space.

[0105] The first insulating member 40 and the fuse portion 33 , and the first insulating member 40 and the wall portion 11 may be connected by bonding, welding or other appropriate means.

[0106] The fuse part 33 is spaced apart from the wall part 11 , and no current flows directly between the fuse part 33 and the wall part 11 . All currents between the wall part 11 and the fuse part 33 flow through the first connecting part 31 , which is conducive to the fuse part 33 being melted in time when an internal short circuit occurs in the battery cell 7 .

[0107] The first insulating member 40 can be an insulating glue, an insulating film, an insulating sheet, etc.

[0108] The first insulating member 40 may be made of a high temperature resistant insulating material. Alternatively, the first insulating member 40 may be made of insulating plastic.

[0109] The melting point of the first insulating member 40 is higher than that of the fuse 33 . After the fuse 33 is blown, the first insulating member 40 can remain between the wall 11 and the first tab 21 to effectively isolate the wall 11 and the first tab 21 .

[0110] The first insulating member 40 can further insulate the fuse portion 33 from the wall portion 11. Moreover, after the fuse portion 33 is blown, the first insulating member 40 can insulate and isolate the wall portion 11 from the first tab 21, reducing the possibility of overlap between the wall portion 11 and the first tab 21 and improving the effectiveness of short-circuit protection.

[0111] In some embodiments, reference Figure 11 The first connecting portion 31 includes a first side surface 311 facing the first insulating member 40 , and the fuse portion 33 includes a first surface 331 facing the wall portion 11 . The first insulating member 40 covers the first side surface 311 and the first surface 331 .

[0112] The first side surface 311 and the first surface 331 may be flat surfaces, curved surfaces, or bent surfaces.

[0113] The first insulating member 40 may be formed between the fuse portion 33 and the wall portion 11 by a coating process.

[0114] The first insulating member 40 covers the first side surface 311 and the first surface 331. After the fuse part 33 is blown, the first insulating member 40 can separate the disconnection space formed by the melting of the fuse part 33 from the wall part 11 along the thickness direction X, thereby reducing the possibility of overlap between the wall part 11 and the first electrode tab 21 and improving the effectiveness of short-circuit protection.

[0115] In some embodiments, reference Figure 11 The first side surface 311 includes a first surface 3111 and a second surface 3112. The first surface 3111 and the second surface 3112 are arranged along the thickness direction X and are staggered with each other in a direction perpendicular to the thickness direction X.

[0116] The first surface 3111 and the second surface 3112 are staggered to form steps, which facilitates the rubber encapsulation between the fuse part 33 and the wall part 11 to form the first insulating part 40, reducing the possibility of the first insulating part 40 detaching from the first side surface 311 and the first surface 331, and improving the stability and insulation isolation effect of the first insulating part 40.

[0117] In some embodiments, reference Figure 6 、 Figure 7 and Figure 9 The battery cell 7 includes a second insulating member 50 , which is disposed between the second connecting portion 32 and the wall portion 11 .

[0118] The second insulating member 50 may be a ring-shaped insulating sheet.

[0119] The second insulating member 50 may be made of a high-temperature resistant insulating material to reduce the impact of a high-temperature environment on the second insulating member 50 when the fuse 33 is blown.

[0120] Two opposite surfaces of the second insulating member 50 along the thickness direction X may respectively abut against the second connecting portion 32 and the wall portion 11. The second insulating member 50 and the second connecting portion 32, as well as the second insulating member 50 and the wall portion 11, may be connected by bonding or other suitable means.

[0121] The second insulating member 50 can insulate and isolate the second connecting portion 32 from the wall portion 11, further reducing the risk of electrical connection between the second connecting portion 32 and the wall portion 11. Furthermore, the second insulating member 50 can also support the second connecting portion 32 suspended on one side of the wall portion 11, thereby indirectly supporting the electrode assembly 20. The force exerted by the electrode assembly 20 on the current collector 30 can be transmitted to the wall portion 11 through the second insulating member 50, reducing the risk of deformation of the second connecting portion 32 and facilitating improved connection reliability between the second connecting portion 32 and the first electrode tab 21.

[0122] In some embodiments, reference Figure 11 The second connection portion 32 includes a second surface 321 facing the wall portion 11, and the first connection portion 31 includes a third surface 312 facing the electrode assembly 20. The second surface 321 and the third surface 312 are flush. Along the thickness direction X, the thickness of the second insulating member 50 is the same as the thickness of the first connection portion 31.

[0123] The second surface 321 is flush with the third surface 312 , and the first connection portion 31 as a whole protrudes from the second connection portion 32 in a direction facing the wall portion 11 .

[0124] The second insulating member 50 is accommodated in the space formed between the second connecting portion 32 and the wall portion 11. The height of this space along the thickness direction X is substantially the same as the thickness of the first connecting portion 31 and the thickness of the second insulating member 50. As a result, the two opposing surfaces of the second insulating member 50 along the thickness direction X abut against the second connecting portion 32 and the wall portion 11, respectively, which helps to improve the support effect of the second insulating member 50 on the second connecting portion 32 and reduces the possibility of displacement of the second insulating member 50.

[0125] In some embodiments, reference Figure 10 and Figure 11 The second connecting portion 32 includes a fourth surface 322 facing the first electrode tab 21. A first recess 34 is provided on the side of the current collector 30 facing the first electrode tab 21. The first recess 34 is recessed into the fourth surface 322. In the thickness direction X of the wall portion 11, the projection of the first connecting portion 31 is located within the projection of the first recess 34.

[0126] The first recess 34 is recessed in the fourth surface 322 toward the wall 11. The recess depth of the first recess 34 may be the same as the thickness of the second connection portion 32, or greater than or equal to the thickness of the second connection portion 32.

[0127] The first connecting portion 31 is disposed opposite to at least a portion of the first recess 34 in the thickness direction X. The first connecting portion 31 can be separated from the first tab 21 by at least a portion of the interior space of the first recess 34 , thereby preventing current from flowing between the first connecting portion 31 and the first tab 21 .

[0128] In some embodiments, the surface of the fuse portion 33 facing the electrode assembly 20 forms a stepped surface 341 of the first recess 34, and the first connection portion 31 forms a bottom surface 342 of the first recess 34 on at least a portion of the surface facing the electrode assembly 20. The bottom surface 342 is closer to the wall portion 11 than the stepped surface 341, and the stepped surface 341 is closer to the wall portion 11 than the fourth surface 322. The first surface 331 of the fuse portion 33 facing the wall portion 11 is flush with the bottom surface 342.

[0129] The interior space of the first recess 34 is enclosed by the first connecting portion 31, the fuse portion 33, and the second connecting portion 32. In the thickness direction X, the first connecting portion 31 corresponds to a portion of the space in the first recess 34, and the fuse portion 33 corresponds to a portion of the space in the first recess 34. The fuse portion 33 is separated from the first electrode tab 21 by the portion of the space in the first recess 34.

[0130] The step surface 341 surrounds the bottom surface 342 in a direction perpendicular to the thickness direction X. The step surface 341 and the bottom surface 342 may both be planes perpendicular to the thickness direction X.

[0131] The first connection portion 31 has a bottom surface 342 at least partially facing the electrode assembly 20. The first surface 331 of the fuse portion 33 is flush with the bottom surface 342. Therefore, along the thickness direction X, the fuse portion 33 and the first connection portion 31 are completely offset.

[0132] The first recess 34 may be formed by an injection molding process or a stamping process.

[0133] In the embodiment of the present application, the first recess 34 is provided to facilitate isolation of the fuse portion 33 from the first electrode tab 21 , and isolation of the first connection portion 31 from the first electrode tab 21 with a simple structure and process.

[0134] In some embodiments, reference Figure 7 and Figure 9 The fuse portion 33 and the first electrode tab 21 are spaced apart from each other along the thickness direction X. The battery cell 7 includes a third insulating member 60 , at least a portion of which is disposed between the fuse portion 33 and the first electrode tab 21 .

[0135] A space is formed between the fuse portion 33 and the first electrode tab 21 , and at least a portion of the third insulating member 60 is located in the space.

[0136] For example, the entire third insulating member 60 may be located between the fuse portion 33 and the first tab 21. As another example, only a portion of the third insulating member 60 may be located between the fuse portion 33 and the first tab 21, and another portion of the third insulating member 60 may be located between the first tab 21 and the first connecting portion 31.

[0137] The space formed between the fuse portion 33 and the first electrode tab 21 may be part of the inner space of the first recess 34. The third insulating member 60 may be entirely accommodated in the first recess 34.

[0138] The fuse part 33 is spaced apart from the first pole tab 21 , and no current flows directly between the fuse part 33 and the wall portion 11 . All current between the first pole tab 21 and the fuse part 33 flows through the second connecting portion 32 , which is conducive to the fuse part 33 being melted in time when an internal short circuit occurs in the battery cell 7 .

[0139] The third insulating member 60 may be an insulating glue, an insulating film, an insulating sheet, or the like.

[0140] The third insulating member 60 may be made of a high temperature resistant insulating material. Alternatively, the third insulating member 60 may be made of insulating plastic.

[0141] The melting point of the third insulating member 60 is higher than that of the fuse 33 . After the fuse 33 is blown, the third insulating member 60 can remain between the wall 11 and the first tab 21 to effectively isolate the wall 11 and the first tab 21 .

[0142] The third insulating member 60 can further insulate the fuse portion 33 from the first tab 21. Moreover, after the fuse portion 33 is blown, the third insulating member 60 can insulate and isolate the wall portion 11 from the first tab 21, reducing the possibility of overlap between the wall portion 11 and the first tab 21 and improving the effectiveness of short-circuit protection.

[0143] In some embodiments, the third insulating member 60 covers at least the surface of the fuse portion 33 facing the electrode assembly 20 and the second side surface 332 of the fuse portion 33 facing away from the second connecting portion 32 .

[0144] Optionally, the surface of the fuse portion 33 facing the electrode assembly 20 is a stepped surface 341 , the stepped surface 341 and the bottom surface 342 may be connected via a second side surface 332 , and the second side surface 332 may extend along the thickness direction X.

[0145] Optionally, the third insulating member 60 may further cover a portion of the bottom surface 342 .

[0146] The third insulating member 60 may be formed between the fuse portion 33 and the first tab 21 by a coating process.

[0147] After the fuse part 33 is blown, the third insulating member 60 can separate the disconnection space formed by the blown fuse part 33 from the first electrode tab 21 along the thickness direction X, thereby reducing the possibility of overlap between the wall portion 11 and the first electrode tab 21 and improving the effectiveness of short circuit protection.

[0148] In some embodiments, the second connection portion 32 surrounds the fuse portion 33 , and the fuse portion 33 and the first connection portion 31 partially overlap in the thickness direction X of the wall portion 11 .

[0149] The fuse part 33 and the first connecting part 31 partially overlap in the thickness direction X. The thickness of the overlapping part is large and the structural strength is high, which is beneficial to reduce the risk of breakage at the connection position between the fuse part 33 and the first connecting part 31 and improve the overall structural strength of the current collecting part 30.

[0150] In some embodiments, reference Figure 11 , the thickness of the fuse portion 33 is smaller than the thickness of the first connection portion 31 and the thickness of the second connection portion 32 .

[0151] The thickness of the first connection portion 31 and the thickness of the second connection portion 32 may be the same or different.

[0152] When the same current flows through the first connecting portion 31 , the second connecting portion 32 and the fuse portion 33 , the fuse portion 33 has a greater resistance to the current due to its smaller thickness, generates more heat, and is more likely to melt.

[0153] If the thickness of the fuse part 33 is too small, the current that can flow through the fuse part 33 is small, which will limit the capacity of the battery cell 7; if the thickness of the fuse part 33 is too large, when an internal short circuit occurs in the battery cell 7, the fuse part 33 is not easy to melt in time, and it is difficult to play a short circuit protection role.

[0154] Therefore, in some embodiments, the thickness of the fuse part 33 may be 0.1 mm to 0.3 mm, thereby balancing the capacity of the battery cell 7 and the short-circuit protection effect of the fuse part 33 .

[0155] Optionally, the thickness of the fuse portion 33 may be 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, or 0.3 mm.

[0156] If the thickness of the first connecting portion 31 is too small, it will affect the current flow capacity; if the thickness of the first connecting portion 31 is too large, it will occupy a larger space in the thickness direction X, affecting the energy density of the battery cell 7, or it will cause the interval between the first connecting portion 31 and the first pole tab 21 to be too small, and the first connecting portion 31 is more likely to be connected to the first pole tab 21.

[0157] To this end, in some embodiments, the thickness of the first connection portion 31 is 0.3 mm to 0.5 mm. This balances the current capacity of the first connection portion 31 with the energy density of the battery cell 7, while also effectively isolating the first connection portion 31 from the first tab 21, thereby improving the effectiveness of short-circuit protection.

[0158] Optionally, the thickness of the first connecting portion 31 may be 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm or 0.5 mm.

[0159] If the thickness of the second connecting portion 32 is too small, it will affect the current flow capacity; if the thickness of the second connecting portion 32 is too large, it will occupy a larger space in the thickness direction X, affecting the energy density of the battery cell 7, or it will cause the interval between the second connecting portion 32 and the wall portion 11 to be too small, and the second connecting portion 32 is more likely to be connected to the wall portion 11.

[0160] To this end, in some embodiments, the thickness of the second connection portion 32 is 0.3 mm to 0.5 mm. This balances the current capacity of the second connection portion 32 with the energy density of the battery cell 7, while also effectively isolating the second connection portion 32 from the wall portion 11, thereby improving the effectiveness of short-circuit protection.

[0161] Optionally, the thickness of the second connecting portion 32 may be 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm or 0.5 mm.

[0162] In some embodiments, reference Figures 6 to 10 The wall portion 11 is provided with a first through hole 111, and the current collector 30 is provided with a second through hole 35. The second through hole 35 communicates with the first through hole 111 and the interior space of the housing 10. The battery cell 7 includes a sealing plate 70. The sealing plate 70 is located on the side of the wall portion 11 facing away from the electrode assembly 20. The sealing plate 70 is connected to the wall portion 11 and blocks the first through hole 111.

[0163] The first through hole 111 penetrates the wall portion 11 along the thickness direction X, and the second through hole 35 penetrates the current collecting member 30 along the thickness direction X.

[0164] Optionally, the first through hole 111 and the second through hole 35 may be arranged opposite to each other along the thickness direction X.

[0165] Optionally, the first through hole 111 and the second through hole 35 are both circular holes, and the central axes of the first through hole 111 and the second through hole 35 coincide with each other.

[0166] The sealing plate 70 may be connected to the wall portion 11 by welding, screw connection, riveting, bonding or other suitable means.

[0167] The material of the sealing plate 70 and the material of the wall portion 11 may be the same or different.

[0168] Optionally, the sealing plate 70 may be made of a material with a certain hardness and strength, such as aluminum, copper, aluminum alloy, plastic, etc.

[0169] For example, the first through hole 111 can be used as a liquid injection hole for the battery cell 7. After the liquid injection is completed, the sealing plate 70 is connected to the wall portion 11 to seal the first through hole 111 to prevent liquid from leaking.

[0170] As another example, first through-hole 111 can also serve as a pressure relief hole for battery cell 7, and sealing plate 70 can be a pressure relief mechanism such as an explosion-proof valve or explosion-proof disk. When high-temperature, high-pressure substances are generated within battery cell 7, the pressure relief substances can be discharged outward through first through-hole 111, breaking through sealing plate 70 and achieving the purpose of pressure relief.

[0171] In some embodiments, reference Figures 7 to 9 A second recess 112 is provided on the side of the wall portion 11 facing away from the electrode assembly 20 , and the sealing plate 70 is entirely accommodated in the second recess 112 .

[0172] The second recess 112 is recessed relative to the surface of the wall 11 facing away from the electrode assembly 20 .

[0173] The sealing plate 70 includes a fifth surface 71 facing away from the electrode assembly 20, and the wall portion 11 includes a sixth surface 113 facing away from the electrode assembly 20. The fifth surface 71 can be flush with the sixth surface 113. The fifth surface 71 can also be offset from the sixth surface 113 along the thickness direction X, and the fifth surface 71 can also be closer to the electrode assembly 20 than the sixth surface 113.

[0174] The second recess 112 provides an accommodating space for the sealing plate 70 . The sealing plate 70 and the wall portion 11 share a portion of the space along the thickness direction X, which is beneficial to improving space utilization and energy density.

[0175] In some embodiments, the interior space of the second recess 112 includes a first portion 1121 and a second portion 1122. The first portion 1121 and the second portion 1122 are arranged along the thickness direction X of the wall portion 11. The first portion 1121 is closer to the electrode assembly 20 than the second portion 1122. In a direction perpendicular to the thickness direction X, the second portion 1122 extends beyond the first portion 1121. The sealing plate 70 is disposed in the first portion 1121 and welded to the wall portion 11.

[0176] The fifth surface 71 of the sealing plate 70 may be flush with the interface between the first portion 1121 and the second portion 1122 .

[0177] Along the thickness direction X, the depth of the second portion 1122 may be smaller than the depth of the first portion 1121 .

[0178] The sealing plate 70 can be welded to the bottom and side surfaces of the second recess 112 that enclose the first portion 1121. The molten pool formed after the sealing plate 70 is welded to the wall portion 11 may protrude beyond the first portion 1121. The second portion 1122 provides space for the molten pool. Furthermore, the portion of space where the second portion 1122 extends beyond the first portion 1121 allows for the molten pool formed after the sealing plate 70 is welded to the wall portion 11, minimizing the protrusion of the molten pool along the thickness direction X. This reduces the likelihood of the molten pool extending beyond the wall portion 11 after the sealing plate 70 is welded to the wall portion 11, thereby improving the appearance of the battery cell 7.

[0179] In some embodiments, reference Figure 7 and Figure 9 The wall portion 11 includes a third connecting portion 114. Along the thickness direction X, the third connecting portion 114 corresponds to at least a portion of the second recess 112. The first through hole 111 is provided in the third connecting portion 114. The first connecting portion 31 is connected to the third connecting portion 114. Along the thickness direction X, the thickness of the third connecting portion 114 is 0.3 mm to 0.5 mm.

[0180] Optionally, the thickness of the third connecting portion 114 may be 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm or 0.5 mm, etc.

[0181] Along the thickness direction X, the third connection portion 114 corresponds to the first portion 1121 of the second recess 112 , and the third connection portion 114 may form a bottom wall of the second recess 112 .

[0182] The first through hole 111 passes through the third connection portion 114 along the thickness direction X. The first connection portion 31 abuts against a surface of the third connection portion 114 facing the electrode assembly 20 .

[0183] If the thickness of the third connecting portion 114 is too large, it will affect the depth of the second recess 112, and the second recess 112 may not be able to fully accommodate the sealing plate 70. If the thickness of the third connecting portion 114 is too small, the structural strength will be reduced and the flow capacity will be reduced. In the embodiment of the present application, the thickness of the third connecting portion 114 is set to 0.3mm to 0.5mm, which is roughly equivalent to the thickness of the first connecting portion 31. This does not occupy a large space and affect the depth of the second recess 112, while also improving its structural strength and flow capacity.

[0184] In some embodiments, reference Figure 7 and Figure 9 The sealing plate 70 includes a main body 72 and a protruding portion 73. The protruding portion 73 surrounds the main body 72 and protrudes from the main body 72 in a direction facing the electrode assembly 20. The protruding portion 73 is connected to the wall portion 11. The main body 72 is spaced apart from the wall portion 11. Along the thickness direction X of the wall portion 11, the projection of the first through hole 111 is located within the projection of the main body 72.

[0185] Optionally, the protrusion 73 may be connected to the third connection portion 114, and the main body 72 and the third connection portion 114 are spaced apart, forming a gap between the main body 72 and the third connection portion 114. Along the thickness direction X, the projection of the main body 72 is located within the projection of the third connection portion 114.

[0186] The main body 72 is spaced apart from the wall 11, forming a gap between the main body 72 and the wall 11. The first through hole 111 can be connected to this gap. When the battery cell 7 releases pressure, this gap can form a vent space. The pressure-releasing material can pass through this vent space to impact the sealing plate 70, facilitating the successful pressure release through the sealing plate 70.

[0187] The first connecting portion 31 and the first pole tab 21 are spaced apart, and the gap between the first connecting portion 31 and the first pole tab 21, the second through hole 35, the first through hole 111, and the gap between the main body 72 and the wall portion 11 are connected in sequence to form an exhaust channel. The pressure relief material inside the battery cell 7 can be discharged outward through the exhaust channel, which is beneficial to improving the pressure relief efficiency and pressure relief effect.

[0188] In some embodiments, the main body portion 72 has a weak portion 74 , and the thickness of the weak portion 74 is smaller than the thickness of other portions of the main body portion 72 except the weak portion 74 .

[0189] The weak portion 74 is thinner than other positions of the main body 72 . When subjected to the same impact, the weak portion 74 is more likely to break, which is beneficial for timely pressure relief of the sealing plate 70 .

[0190] In some embodiments, the housing 10 includes a shell 12 and an end cap 13. The shell 12 includes an integrally formed side wall 121 and an end wall 122. The side wall 121 surrounds the electrode assembly 20. The end wall 122 and the end cap 13 are opposite each other along the thickness direction X of the wall portion 11. The end cap 13 is sealed to the side wall 121. The wall portion 11 is the end wall 122.

[0191] The housing 12 has an opening on a side facing away from the end wall 122 , and the end cover 13 covers the opening of the housing 12 .

[0192] The end cover 13 may be insulated from the side wall 121 or may be electrically connected to the side wall 121 .

[0193] The end wall 122 may be a bottom wall of the housing 12 .

[0194] In some embodiments, the battery cell 7 includes a pressure relief mechanism located on the end cap 13. When a short circuit or overcharge occurs, thermal runaway may occur within the battery cell, causing a sudden increase in pressure. In this case, the pressure relief mechanism is activated to release the internal pressure, preventing the battery cell from exploding or catching fire.

[0195] The sealing plate 70 can assist the pressure relief mechanism in relieving pressure from the battery cell 7. The sealing plate 70 and the pressure relief mechanism are respectively provided on the end wall 122 and the end cover 13, and can relieve pressure from two different directions at the same time, which is conducive to improving the pressure relief efficiency.

[0196] In some embodiments, the battery cell 7 includes an electrode terminal 80 disposed on a side of the end cap 13 facing away from the electrode assembly 20 . The electrode assembly 20 includes a second tab 22 , which has opposite polarity to the first tab 21 and is connected to the electrode terminal 80 .

[0197] The electrode terminal 80 is insulated from the end cap 13. Optionally, the electrode terminal 80 can be insulated from the end cap 13 by insulating plastic.

[0198] The second electrode tab 22 may be disposed on a side of the electrode body 23 facing the end cap 13 so as to be connected to the electrode terminal 80 .

[0199] If the second pole tab 22 is overlapped with the side wall 121 through metal wire or conductive particles, the first pole tab 21 and the second pole tab 22 are short-circuited through the side wall 121 and the wall portion 11, and the fuse portion 33 can be melted under the action of instantaneous high temperature, thereby disconnecting the current loop inside the battery cell 7 and playing a short-circuit protection role.

[0200] In some embodiments, the battery cell 7 is a cylindrical battery cell.

[0201] In a cylindrical battery cell, the current collector 30 may be a circular ring-shaped structure, for example, a ring-shaped current collecting plate. The first connecting portion 31, the fuse portion 33, and the second connecting portion 32 of the current collector 30 may all be ring-shaped structures.

[0202] In a cylindrical battery cell, the sealing plate 70 may be a circular structural member, for example, the sealing plate 70 may be a circular plate body.

[0203] In a cylindrical battery cell, the first insulating member 40 , the second insulating member 50 , and the third insulating member 60 may all be ring-shaped structural members.

[0204] The thickness direction X of the wall portion 11 is the axial direction of the cylindrical battery cell.

[0205] According to the second aspect of the present application, an embodiment of the present application further provides a battery device 2, which includes a plurality of battery cells 7 provided according to any embodiment of the present application.

[0206] According to a third aspect of the present application, an embodiment of the present application further provides an electrical device, which includes a battery device 2 provided according to any embodiment of the present application, and the battery device 2 is used to provide electrical energy.

[0207] The embodiment of the present application provides a cylindrical battery cell 7, which includes a shell 12, an electrode assembly 20, a current collector 30 and a sealing plate 70. The shell 12 has an end wall 122, which can serve as the bottom wall of the shell 12. The electrode assembly 20 is disposed in the shell 12, and the side of the electrode assembly 20 facing the end wall 122 includes a first pole tab 21. The current collector 30 is disposed between the first pole tab 21 and the end wall 122, and the current collector 30 includes a first connecting portion 31, a second connecting portion 32 and a fuse portion 33. The first connecting portion 31 protrudes from the second connecting portion 32 in a direction close to the end wall 122 and abuts against the end wall 122, and the first connecting portion 31 is spaced apart from the first pole tab 21. The second connecting portion 32 surrounds the first connecting portion 31, is connected to the first pole tab 21 and is spaced apart from the end wall 122, and a third insulating member 60 is provided between the second connecting portion 32 and the end wall 122. The fuse portion 33 connects the first connecting portion 31 and the second connecting portion 32. The fuse portion 33 is spaced apart from both the first tab 21 and the end wall 122. Insulating adhesive is applied to the surface of the fuse portion 33 facing the first tab 21 and the surface of the fuse portion 33 facing the end wall 122. The thickness of the fuse portion 33 is smaller than that of the first connecting portion 31 and the second connecting portion 32. The thickness of the fuse portion 33 is 0.1 mm to 0.3 mm. The thickness of the first connecting portion 31 is 0.3 mm to 0.5 mm, and the thickness of the second connecting portion 32 is 0.3 mm to 0.5 mm.

[0208] The end wall 122 is provided with a first through hole 111, which can be a liquid injection hole. The current collecting part 30 is provided with a second through hole 35, and the first through hole 111 is connected to the second through hole 35. The sealing plate 70 is welded to the end wall 122 and blocks the first through hole 111. The cross section of the sealing plate 70 taken along the thickness direction X is "concave". A second recess 112 is provided on the side of the end wall 122 away from the electrode assembly 20. The second recess 112 is in the shape of three steps arranged along the thickness direction X. The third step closest to the electrode assembly 20 is used for welding the current collecting part 30, and the second step adjacent to the third step is used for welding the sealing plate 70. The outermost first step is used to reduce the possibility of the molten pool protruding from the end wall 122 after welding the sealing plate 70 and the end wall 122.

[0209] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: a housing including a wall portion; an electrode assembly housed in the housing, wherein the electrode assembly has a first electrode tab on a side facing the wall; as well as A current collecting part is arranged between the first pole lug and the wall portion, and the current collecting part includes a first connecting part, a second connecting part and a fuse part; the first connecting part is connected to the wall portion and is spaced apart from the first pole lug; the second connecting part surrounds the first connecting part, the second connecting part is connected to the first pole lug and is spaced apart from the wall portion; the fuse part connects the first connecting part and the second connecting part, and the fuse part is spaced apart from both the first pole lug and the wall portion.

2. The battery cell according to claim 1, wherein: At least a portion of the first connecting portion protrudes from the second connecting portion in a direction close to the wall portion and abuts against the wall portion; The second connection portion and the wall portion are spaced apart from each other along a thickness direction of the wall portion.

3. The battery cell according to claim 2, characterized in that: The fuse portion and the wall portion are spaced apart along the thickness direction; The battery cell includes a first insulating member disposed between the fuse portion and the wall portion.

4. The battery cell according to claim 3, characterized in that The first connecting portion includes a first side surface facing the first insulating member, and the fuse portion includes a first surface facing the wall portion; The first insulating member covers the first side surface and the first surface.

5. The battery cell according to claim 4, characterized in that The first side surface includes a first surface and a second surface. The first surface and the second surface are arranged along the thickness direction and staggered with each other in a direction perpendicular to the thickness direction.

6. The battery cell according to claim 2, characterized in that The battery cell includes a second insulating member disposed between the second connecting portion and the wall portion.

7. The battery cell according to claim 6, characterized in that The second connecting portion includes a second surface facing the wall portion, the first connecting portion includes a third surface facing the electrode assembly, and the second surface and the third surface are flush; Along the thickness direction, the thickness of the second insulating member is the same as the thickness of the first connecting portion.

8. The battery cell according to claim 1, wherein: The second connecting portion includes a fourth surface facing the first electrode tab, and a first recess is provided on a side of the current collecting member facing the first electrode tab, wherein the first recess is recessed in the fourth surface; In the thickness direction of the wall portion, a projection of the first connecting portion is located within a projection of the first recessed portion.

9. The battery cell according to claim 8, characterized in that The surface of the fuse portion facing the electrode assembly forms a stepped surface of the first recess, and the first connecting portion faces at least a portion of the surface of the electrode assembly to form a bottom surface of the first recess, wherein the bottom surface is closer to the wall portion than the stepped surface, and the stepped surface is closer to the wall portion than the fourth surface; A first surface of the fuse portion facing the wall portion is flush with the bottom surface.

10. The battery cell according to claim 1, characterized in that The fuse portion and the first tab are spaced apart from each other along the thickness direction of the wall portion; The battery cell includes a third insulating member, at least a portion of which is disposed between the fuse portion and the first tab.

11. The battery cell according to claim 10, characterized in that The third insulating member at least covers a surface of the fuse portion facing the electrode assembly and a second side surface of the fuse portion facing away from the second connecting portion.

12. The battery cell according to claim 1, wherein The second connection portion surrounds the fuse portion, and the fuse portion and the first connection portion partially overlap in a thickness direction of the wall portion.

13. The battery cell according to claim 1, characterized in that The thickness of the fuse portion is smaller than the thickness of the first connection portion and the thickness of the second connection portion.

14. The battery cell according to claim 13, characterized in that The thickness of the fuse portion is 0.1 mm to 0.3 mm; and / or The thickness of the first connecting portion is 0.3 mm to 0.5 mm; and / or The thickness of the second connecting portion is 0.3 mm to 0.5 mm.

15. The battery cell according to claim 1, characterized in that The wall portion is provided with a first through hole, the current collecting member is provided with a second through hole, and the second through hole is connected to the first through hole and the internal space of the shell; The battery cell includes a sealing plate, which is located on a side of the wall portion away from the electrode assembly. The sealing plate is connected to the wall portion and blocks the first through hole.

16. The battery cell according to claim 15, characterized in that A second recess is provided on a side of the wall portion facing away from the electrode assembly, and the sealing plate is entirely accommodated in the second recess.

17. The battery cell according to claim 16, characterized in that The inner space of the second recess includes a first portion and a second portion, the first portion and the second portion are arranged along the thickness direction of the wall portion, the first portion is closer to the electrode assembly than the second portion, and the second portion exceeds the first portion in a direction perpendicular to the thickness direction; The sealing plate is arranged on the first portion and welded to the wall portion.

18. The battery cell according to claim 16, characterized in that The wall portion includes a third connecting portion, and along the thickness direction of the wall portion, the third connecting portion corresponds to at least a portion of the second recessed portion, and the first through hole is provided in the third connecting portion; The first connection portion is connected to the third connection portion, and the thickness of the third connection portion is 0.3 mm to 0.5 mm.

19. The battery cell according to claim 15, characterized in that The sealing plate includes a main body and a protruding portion, wherein the protruding portion surrounds the main body and protrudes from the main body in a direction facing the electrode assembly; The protruding portion is connected to the wall portion, the main body portion is spaced apart from the wall portion, and along the thickness direction of the wall portion, the projection of the first through hole is located within the projection of the main body portion.

20. The battery cell according to claim 19, characterized in that The main body has a weak portion, and a thickness of the weak portion is smaller than a thickness of other portions of the main body except the weak portion.

21. The battery cell according to claim 1, characterized in that The housing includes a shell and an end cap, the shell includes an integrally formed side wall and an end wall, the side wall surrounds the electrode assembly, the end wall and the end cap are opposite to each other along the thickness direction of the wall portion, and the end cap is sealed to the side wall; The wall portion is the end wall.

22. The battery cell according to claim 21, characterized in that The battery cell includes an electrode terminal, and the electrode terminal is provided on a side of the end cap away from the electrode assembly; The electrode assembly includes a second electrode tab having a polarity opposite to that of the first electrode tab, and the second electrode tab is connected to the electrode terminal.

23. The battery cell according to claim 1, characterized in that The battery cell is a cylindrical battery cell.

24. A battery device, characterized in that: The method comprises a plurality of battery cells according to any one of claims 1 to 23.

25. An electrical device, characterized in that: The battery device according to claim 24 is included, and is used to provide electrical energy.

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