Battery cell, battery, electrical equipment, manufacturing equipment and method of battery cell

Abstract

The present application provides a battery cell, a battery, an electrical device, a manufacturing apparatus and method for a battery cell, relating to the technical field of batteries. The battery cell includes an electrode assembly, a housing, an end cap, a first current collector member and a second current collector member; a first limiting portion is convexly provided on the inner side surface of the housing; the first current collector member is used for connecting a tab; the second current collector member is used for connecting the first current collector member and the first limiting portion; the first current collector member includes a first region overlapping with the first limiting portion in the thickness direction and a second region not overlapping with the first limiting portion, and both the first region and the second region are welded to the tab. The first region can be welded to the tab of the outer layer, and the second region can be welded to the tab of the inner layer, which can achieve uniform current conduction and avoid the problem that the tab of the outer layer cannot be connected to the current collector member and there is excessive local overcurrent, thereby reducing the risk of serious polarization of the tab of the outer layer during the cyclic charge and discharge process.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and more specifically, to a battery cell, a battery, an electrical device, a manufacturing apparatus and method for a battery cell. Background Art

[0002] Currently, the batteries most commonly used in vehicles are generally lithium-ion batteries. As a rechargeable battery, a lithium-ion battery has the advantages of small size, high energy density, high power density, a large number of charge-discharge cycles, and a long storage time.

[0003] A battery cell generally includes a housing and an electrode assembly. The housing is used to accommodate the electrode assembly and electrolyte. The electrode assembly generally includes a positive electrode tab and a negative electrode tab, and electrical energy is generated by the movement of metal ions (such as lithium ions) between the positive electrode tab and the negative electrode tab.

[0004] For a general battery cell, the electrode assembly needs to be electrically connected to the housing so that the housing serves as the positive output terminal or the negative output terminal of the battery cell. Currently, it is inconvenient to electrically connect the electrode assembly to the housing. Summary of the Invention

[0005] Embodiments of the present application provide a battery cell, a battery, an electrical device, a manufacturing apparatus and method for a battery cell, so as to facilitate the electrical connection between the electrode assembly and the housing.

[0006] In a first aspect, an embodiment of the present application provides a battery cell, including an electrode assembly, a housing, an end cap, a first current collector member, and a second current collector member; the electrode assembly has an electrode tab; the housing has an opening, and the housing is used to accommodate the electrode assembly, and a first limiting portion is convexly provided on the inner side surface of the housing; the end cap is used to cover the opening, and the first limiting portion is used to limit the end cap from moving in a direction close to the electrode assembly; the first current collector member is located on a side of the first limiting portion facing the electrode assembly along the thickness direction of the end cap, and the first current collector member is used to connect the electrode tab; the second current collector member is located on a side of the first current collector member facing away from the electrode assembly along the thickness direction, and the second current collector member is used to connect the first current collector member and the first limiting portion; wherein, the first current collector member includes a first region overlapping with the first limiting portion along the thickness direction and a second region not overlapping with the first limiting portion along the thickness direction, and both the first region and the second region are welded to the electrode tab.

[0007] In the above technical solution, the first connecting member includes a first region that overlaps with the first limiting portion in the thickness direction of the end cap and a second region that does not overlap with the first limiting portion in the thickness direction of the end cap. The first region can be welded to the tab of the outer layer, and the second region can be welded to the tab of the inner layer. Therefore, the tabs of both the inner layer and the outer layer can be connected to the first current collecting member, enabling uniform current conduction, avoiding the problem of excessive local current flow due to the inability of the tabs of the outer layer to be connected to the current collecting member, thereby reducing the risk of severe polarization of the tabs of the outer layer during the cyclic charge and discharge process, and thus reducing the risk of lithium plating caused by polarization. In addition, since the first current collecting member and the second current collecting member are separately provided, the first current collecting member can be first connected to the tab without being restricted by the housing structure, and then the first current collecting member and the first limiting portion of the housing can be connected through the second current collecting member, thereby conveniently connecting the electrode assembly and the housing.

[0008] In some embodiments of the first aspect of the present application, the second current collecting member includes a body portion and a connecting portion; the body portion is stacked with the first current collecting member in the thickness direction, and the body portion is used to connect to the side of the first current collecting member facing away from the electrode assembly; the connecting portion is connected to the body portion, and a part of the connecting portion extends to the side of the first limiting portion in its protruding direction to connect the first current collecting member and the first limiting portion.

[0009] In the above technical solution, the body portion is stacked with the first current collecting member in the thickness direction and is electrically connected to the first current collecting member, which can improve the current conduction ability of the battery cell. A part of the connecting portion extends to the side of the first limiting portion in its protruding direction, thereby connecting the first current collecting member and the first limiting portion, increasing the contact area between the second current collecting member and the first limiting portion, and increasing the current passing area between the housing and the second current collecting member.

[0010] In some embodiments of the first aspect of the present application, the connecting portion includes a first connecting portion and a second connecting portion; the first connecting portion is used to abut against the side of the first limiting portion in its protruding direction; the second connecting portion is connected to the end of the first connecting portion facing away from the body portion, and the second connecting portion is used to abut against the side of the first limiting portion facing away from the electrode assembly.

[0011] In the above technical solution, the first connecting portion abuts against the side of the first limiting portion in its protruding direction, and the second connecting portion abuts against the side of the first limiting portion facing away from the electrode assembly, improving the connection stability between the connecting portion and the first limiting portion, and also increasing the contact area between the second current collecting member and the first limiting portion, and increasing the current passing area between the housing and the second current collecting member.

[0012] In some embodiments of the first aspect of the present application, the first connecting portion extends along the thickness direction.

[0013] In the above technical solution, the first connecting portion extends along the thickness direction of the end cover, so that the distance for the first extending portion to extend to abut against the first limiting portion on the side of its protruding direction is the shortest, reducing the space occupied by the first connecting portion inside the battery cell.

[0014] In some embodiments of the first aspect of the present application, the first connecting portion is a closed-loop structure extending along the circumferential direction of the housing.

[0015] In the above technical solution, the first connecting portion is a closed-loop structure, which can increase the contact area between the first connecting portion and the first limiting portion, thereby increasing the current-carrying area between the housing and the second current collecting member.

[0016] In some embodiments of the first aspect of the present application, the second connecting portion is a closed-loop structure surrounding the edge of the first connecting portion.

[0017] In the above technical solution, the second connecting portion is a closed-loop structure, which can increase the contact area between the second connecting portion and the first limiting portion, thereby increasing the current-carrying area between the housing and the second current collecting member.

[0018] In some embodiments of the first aspect of the present application, the first current collecting member and the second current collecting member form a plug-in fit along the thickness direction.

[0019] In the above technical solution, the first current collecting member and the second current collecting member form a plug-in fit along the thickness direction of the end cover, so that the first current collecting member and the second current collecting member can be plugged and positioned, improving the stability of the relative position relationship between the first current collecting member and the second current collecting member, facilitating the welding of the first current collecting member and the second current collecting member and improving the stability of power output.

[0020] In some embodiments of the first aspect of the present application, a groove is formed on the side of the first current collecting member facing the end cover, and a part of the second current collecting member is received in the groove.

[0021] In the above technical solution, the second current collector is plugged into the groove on the side of the first current collecting member facing the end cover, which not only enables the first current collecting member and the second current collecting member to be plugged and positioned, improving the stability of the relative position relationship between the first current collecting member and the second current collecting member, facilitating the welding of the first current collecting member and the second current collecting member and improving the stability of power output; but also reduces the space occupied by the first current collecting member and the second current collecting member in the thickness direction of the end cover. And the thickness of the position where the first current collecting member is provided with the groove is smaller, facilitating the welding of the first current collecting member and the tab.

[0022] In some embodiments of the first aspect of the present application, the first current collector member is provided with a central hole penetrating through the first current collector member in the thickness direction, and a flow guiding groove is formed on one side of the first current collector member facing the electrode assembly. The flow guiding groove is configured to guide the electrolyte entering the electrode assembly through the central hole to the outer periphery.

[0023] In the above technical solution, the flow guiding groove can guide the electrolyte in the central hole to areas outside the central hole, so that the electrolyte is evenly distributed inside the battery cell, thereby fully and evenly wetting the electrode assembly and reducing the possibility of lithium plating in the battery cell.

[0024] In some embodiments of the first aspect of the present application, a first recess is formed on the housing, which is recessed inward from the outer peripheral wall of the housing, and a first limiting portion protruding from the inner peripheral wall of the housing is formed at a position corresponding to the first recess on the housing. Both the first recess and the first limiting portion are annular structures.

[0025] In the above technical solution, it is difficult to form the first limiting portion on the inner wall of the housing, while the difficulty of forming the first recess on the outer peripheral wall of the housing is lower than that of directly forming the first limiting portion on the inner wall of the housing. Therefore, by forming a first limiting portion protruding from the inner peripheral wall of the housing at a position corresponding to the first recess on the housing, the forming difficulty of the first limiting portion is reduced.

[0026] In some embodiments of the first aspect of the present application, the housing has a second limiting portion; in the thickness direction of the end cover, the second limiting portion and the first limiting portion are used to jointly limit the movement of the end cover relative to the housing in the thickness direction.

[0027] In the above technical solution, the second limiting portion and the first limiting portion cooperate to jointly limit the movement of the end cover relative to the housing in the thickness direction of the end cover, so that the end cover and the housing maintain a stable connection relationship.

[0028] In some embodiments of the first aspect of the present application, the second limiting portion is a flanging structure formed by the housing turning inward at the opening position.

[0029] In the above technical solution, the second limiting portion is a flanging structure formed by the housing turning inward at the opening position, that is, the second limiting portion is a part of the housing, so that the second limiting portion can stably limit the end cover on the side of the end cover facing away from the electrode assembly. And the second limiting portion is a part of the housing, which can also reduce the connection relationship of the housing, thereby improving the structural strength of the housing.

[0030] In some embodiments of the first aspect of the present application, the battery cell further includes a sealing member, and the sealing member seals between the first limiting portion and the end cover and between the second limiting portion and the end cover.

[0031] In the above technical solution, the sealing performance of the battery cell is improved by sealing between the first limiting portion and the end cover and between the second limiting portion and the end cover with a seal.

[0032] In a second aspect, an embodiment of the present application provides a battery, including the battery cell according to any one of the embodiments of the first aspect.

[0033] In the above technical solution, the battery cell includes a first current collector member and a second current collector member. The first current collector member is connected to the tab, and the second current collector member connects the first current collector member and the first limiting portion of the housing. The first region of the first member can be welded to the tab of the outer layer, and the second region of the first member can be welded to the tab of the inner layer. Therefore, the tabs of both the inner layer and the outer layer can be connected to the first current collector member, enabling uniform current conduction, avoiding the problem of excessive local current due to the inability of the tabs of the outer layer to be connected to the current collector member, thereby reducing the risk of severe polarization of the tabs of the outer layer during the cyclic charge and discharge process, thus reducing the risk of lithium deposition caused by polarization, and thereby improving the safety performance of the battery.

[0034] In a third aspect, an embodiment of the present application provides an electrical device, including the battery provided by the embodiment of the second aspect.

[0035] In the above technical solution, the battery will not have the problem of excessive local current due to the inability of the outer tabs to be connected to the current collector member, thereby reducing the risk of severe polarization of the outer tabs during the cyclic charge and discharge process, thus reducing the risk of lithium deposition, and thereby improving the electrical safety of the electrical device.

[0036] In a fourth aspect, an embodiment of the present application provides a manufacturing device for a battery cell, including a providing device and an assembling device; the providing device is configured to provide an electrode assembly, a housing, an end cover, a first current collector member, and a second current collector member, and the electrode assembly has tabs; the housing has an opening, and the housing is used to accommodate the electrode assembly. The inner side surface of the housing is convexly provided with a first limiting portion, and the first limiting portion is used to limit the movement of the end cover in the direction close to the electrode assembly; the end cover is used to cover the opening; the assembling device is configured to accommodate the electrode assembly in the housing, connect the first current collector member to the tab, connect the second current collector member to the first current collector member and the first limiting portion, and seal the end cover to the opening; wherein, the first current collector member includes a first region that overlaps with the first limiting portion along the thickness direction of the end cover and a second region that does not overlap with the first limiting portion along the thickness direction, and both the first region and the second region are welded to the tab.

[0037] In a fifth aspect, an embodiment of the present application provides a manufacturing method for a battery cell, and the manufacturing method includes:

[0038] An electrode assembly, a housing, an end cap, a first current collecting member, and a second current collecting member are provided. The electrode assembly has a tab. The housing has an opening and is used to accommodate the electrode assembly. A first limiter is provided on an inner side surface of the housing. The first limiter is used to limit the end cap from moving toward the electrode assembly.

[0039] connecting the first current collecting member to the electrode tab;

[0040] connecting the second current collecting member to the first current collecting member;

[0041] accommodating the electrode assembly in the housing and connecting the second current collecting member to the first limiting portion;

[0042] sealing the end cap to the opening;

[0043] The first current collecting member includes a first region overlapping with the first limiting portion along a thickness direction of the end cover and a second region not overlapping with the first limiting portion along the thickness direction, and both the first region and the second region are welded to the tab. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0045] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0046] Figure 2 A schematic diagram of the structure of a battery provided in some embodiments of the present application;

[0047] Figure 3 A schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0048] Figure 4 for Figure 3 sectional view of

[0049] Figure 5 for Figure 4 The enlarged view of point I in the middle;

[0050] Figure 6 An axonometric view of a second current collecting member provided in some embodiments of the present application;

[0051] Figure 7 forFigure 6 Cross-sectional view of the second current collector member in

[0052] Figure 8 Cross-sectional view of a battery cell provided for other embodiments of the present application;

[0053] Figure 9 is Figure 8 Enlarged view at II in

[0054] Figure 10 Schematic structural diagram of the second current collector member provided for other embodiments of the present application;

[0055] Figure 11 is Figure 10 Cross-sectional view of the second current collector member in

[0056] Figure 12 Schematic diagram of the plug-in fit between the first current collector member and the second current collector member provided for some embodiments of the present application;

[0057] Figure 13 Schematic diagram of the plug-in fit between the first current collector member and the second current collector member provided for other embodiments of the present application;

[0058] Figure 14 Schematic structural diagram of the first current collector provided for some embodiments of the present application;

[0059] Figure 15 Schematic structural diagram of the electrode assembly provided for some embodiments of the present application;

[0060] Figure 16 Schematic diagram after welding the tab of the electrode assembly and the first current collector member provided for some embodiments of the present application;

[0061] Figure 17 Schematic structural diagram of the manufacturing equipment of the battery cell provided for some embodiments of the present application;

[0062] Figure 18 Flow chart of the manufacturing method of the battery cell provided for some embodiments of the present application.

[0063] Icons: 1000 - vehicle; 100 - battery; 10 - housing; 11 - installation space; 12 - first part; 13 - second part; 20 - battery cell; 21 - electrode assembly; 211 - tab; 212 - recess; 213 - first welding mark area; 22 - housing; 221 - opening; 222 - first limiting part; 2221 - first connecting section; 2222 - second connecting section; 2223 - third connecting section; 223 - first recess; 224 - second limiting part; 23 - end cap; 231 - pressure relief mechanism; 24 - first current collecting member; 241 - first area; 242 - second area; 243 - groove; 244 - central hole; 245 - flow guiding groove; 246 - second welding mark area; 25 - second current collecting member; 251 - body part; 2511 - first body part; 2512 - second body part; 2513 - through hole; 252 - connecting part; 2521 - first connecting part; 2522 - second connecting part; 26 - electrode terminal; 27 - seal; 271 - first sealing part; 272 - second sealing part; 273 - third sealing part; 200 - controller; 300 - motor; 2000 - manufacturing equipment for battery cells; 2100 - providing device; 2200 - assembling device; X - thickness direction of the end cap. Detailed Description of the Embodiment

[0064] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. The components of the embodiments of the present application usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0065] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application claimed, but merely represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts fall within the scope of protection of the present application.

[0066] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0067] It should be noted that like reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0068] In the description of the embodiments of the present application, it should be noted that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of this application is usually placed during use, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0069] At present, from the perspective of the development of the market situation, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely used in electric transportation tools such as electric bicycles, electric motorcycles, and electric vehicles, as well as in multiple fields such as military equipment and aerospace. With the continuous expansion of the application fields of power batteries, the market demand is also continuously increasing.

[0070] In the prior art, a battery cell includes an electrode assembly, a housing, an end cap, and a current collector member. The electrode assembly is accommodated in the housing. The inner side surface of the housing is convexly provided with a first limiting portion, and the first limiting portion is used to limit the end cap from moving in the direction close to the electrode assembly along its thickness direction when the end cap covers the opening of the housing. The current collector member is disposed on the side of the tab facing the end cap. The current collector member includes a first current collecting portion and a second current collecting portion. The first current collecting portion is used for welding with the tab, and the second current collecting portion is connected to the first current collecting portion and extends in the direction close to the end cap in the thickness direction of the end cap to abut against the inner side surface of the first limiting portion along its convex direction, so as to realize the electrical connection between the tab and the first limiting portion through the current collector member.

[0071] The inventor found that since the second current collecting portion abuts against the inner side surface of the first limiting portion along its convex direction, the size of the portion of the first current collecting portion located outside the second current collecting portion is very small or even non-existent, so that the portion of the tab located outside the second current collecting portion cannot be welded to the first current collecting portion; or the tab is a flattened tab, and there is a large slope in the tab outside the second current collecting portion, resulting in the inability of this portion of the tab to be welded to the first current collecting portion. Then, it is easy to have the problem that some tabs cannot be connected to the current collector member and there is a problem of excessive local overcurrent, and there is a serious polarization phenomenon on the side of the non-welded tab during the cyclic charge and discharge process. Even more seriously, lithium deposition occurs on the tab side, seriously affecting the safety performance of the battery cell.

[0072] Based on the above considerations, in order to alleviate the problem that the tab of the outer layer cannot be welded to the current collector member, resulting in excessive local overcurrent, and then serious polarization of the tab of the outer layer during the charge and discharge cycle, the embodiment of the present application provides a battery cell. The battery cell includes a first current collector member and a second current collector member that are separately arranged; the first current collector member is used to connect to the tab of the electrode assembly, and the first current collector member and the first limiting portion are connected through the second current collector member; the first current collector member includes a first region that overlaps with the first limiting portion along the thickness direction of the end cover and a second region that does not overlap with the first limiting portion along the thickness direction. Both the first region and the second region are welded to the tab. The first region can be welded to the tab of the outer layer, and the second region can be welded to the tab of the inner layer. Therefore, the tabs of both the inner layer and the outer layer can be connected to the first current collector member, enabling uniform current conduction and avoiding the problem of excessive local overcurrent due to the inability of the tab of the outer layer to be connected to the current collector member, thereby reducing the risk of serious polarization of the tab of the outer layer during the charge and discharge cycle, and reducing the risk of lithium deposition caused by polarization. In addition, since the first current collector member and the second current collector member are separately arranged, the first current collector member can be first connected to the tab without being restricted by the housing structure, and then the first current collector member and the first limiting portion 222 of the housing can be connected through the second current collector member, thus conveniently realizing the connection between the electrode assembly and the housing.

[0073] The battery cell disclosed in the embodiment of the present application can be but is not limited to being used in power-consuming devices such as vehicles, ships, or aircraft. A power supply system of the power-consuming device can be composed of the battery cell, battery, etc. disclosed in the present application. In this way, it is beneficial to alleviate the problem that the tab of the outer layer cannot be welded to the current collector member, resulting in excessive local overcurrent, and then serious polarization of the tab of the outer layer during the charge and discharge cycle, reduce the risk of lithium deposition in the battery cell, and improve the safety performance of the battery cell.

[0074] The technical solutions described in the embodiments of the present application are applicable to batteries and power-consuming devices using batteries.

[0075] The power-consuming device can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, etc. The vehicle 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.; the spacecraft includes an airplane, a rocket, a space shuttle, a spaceship, etc.; the electric toy includes a fixed or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy, an electric airplane toy, etc.; the electric tool includes a metal-cutting electric tool, a grinding electric tool, an assembly electric tool, and a railway electric tool, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, a hammer drill, an impact electric drill, a concrete vibrator, an electric planer, etc. The embodiments of the present application do not impose special restrictions on the above power-consuming devices.

[0076] In the following embodiments, for the sake of convenience of description, the electrical device is taken as an example of the vehicle 1000 for illustration.

[0077] Please refer to Figure 1 , Figure 1 , which is a schematic structural diagram of the vehicle 1000 provided in some embodiments of the present application. A battery 100 is disposed inside the vehicle 1000, and the battery 100 can be disposed at the bottom, head or tail of the vehicle 1000. The battery 100 can be used for power supply of the vehicle 1000. For example, the battery 100 can be used as the operating power source of the vehicle 1000.

[0078] The vehicle 1000 may further include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300. For example, it is used for the working power requirements during the start, navigation and driving of the vehicle 1000.

[0079] In some embodiments of the present application, the battery 100 can not only be used as the operating power source of the vehicle 1000, but also be used as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0080] Please refer to Figure 2 , Figure 2 , which is a schematic structural diagram of the battery 100 provided in some embodiments of the present application. The battery 100 includes a box body 10 and battery cells 20, and the battery cells 20 are received in the box body 10.

[0081] The box body 10 is used to provide an installation space 11 for the battery cells 20. In some embodiments, the box body 10 may include a first part 12 and a second part 13. The first part 12 and the second part 13 are covered with each other to define an installation space 11 for accommodating the battery cells 20. Of course, the connection between the first part 12 and the second part 13 can be sealed by a sealing member 27 (not shown in the figure), and the sealing member 27 can be a sealing ring, a sealant, etc.

[0082] The first part 12 and the second part 13 can be of various shapes. For example, a cuboid, a cylinder, etc. The first part 12 can be a hollow structure with an opening 221 on one side to form a receiving cavity. The second part 13 can also be a hollow structure with an opening 221 on one side to form a receiving cavity. The opening side of the second part 13 is covered with the opening side of the first part 12, then the box body 10 with the installation space 11 is formed. Of course, it can also be that the first part 12 is a hollow structure with an opening 221 on one side to form a receiving cavity, and the second part 13 is a plate-like structure. The second part 13 is covered with the opening side of the first part 12, then the box body 10 with the installation space 11 is formed.

[0083] In the battery 100, there can be one or more battery cells 20. If there are multiple battery cells 20, they can be connected in series, parallel, or in a combination of series and parallel (mixed connection). A mixed connection means that among the multiple battery cells 20, there are both series and parallel connections. The multiple battery cells 20 can be directly connected in series, parallel, or in a mixed connection together, and then the whole formed by the multiple battery cells 20 is accommodated in the box 10. Of course, it is also possible that the multiple battery cells 20 are first connected in series, parallel, or in a mixed connection to form battery modules, and then the multiple battery modules are connected in series, parallel, or in a mixed connection to form a whole and are accommodated in the box 10. The battery cell 20 can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc. Figure 2 An example shows the case where the battery cell 20 is in the shape of a cylinder.

[0084] In some embodiments, the battery 100 may further include a busbar component (not shown in the figure). The multiple battery cells 20 can be electrically connected through the busbar component to achieve series, parallel, or mixed connection of the multiple battery cells 20.

[0085] Please refer to Figure 3 、 Figure 4 、 Figure 5 , Figure 3 which is a schematic structural view of the battery cell 20 provided in some embodiments of the present application. Figure 4 For Figure 3 is a cross-sectional view, Figure 5 and Figure 4 is an enlarged view of part I in

[0086] The housing 22 can be of various shapes, such as a cylinder, a cuboid, etc. The shape of the housing 22 can be determined according to the specific shape of the electrode assembly 21. For example, if the electrode assembly 21 is a cylinder structure, the housing 22 can be selected as a cylinder structure; if the electrode assembly 21 is a cuboid structure, the housing 22 can be selected as a cuboid structure. Figure 3 An example shows the case where the housing 22 and the electrode assembly 21 are cylinders.

[0087] The material of the housing 22 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and the embodiments of the present application do not impose special restrictions on this.

[0088] In the thickness direction X of the end cap mentioned in the embodiments of the present application, if the battery cell 20 is a cylindrical structure, the thickness direction X of the end cap is also the axial direction of the battery cell 20. The protruding direction of the first limiting portion 222 is perpendicular to the thickness direction X of the end cap.

[0089] The end cap 23 is used to seal the opening 221 of the housing 22 to form a closed accommodation space (not shown in the figure), and the accommodation space is used to accommodate the electrode assembly 21. The accommodation space is also used to accommodate an electrolyte, such as an electrolytic solution.

[0090] It should be noted that the opening 221 of the housing 22 can be one or two. If the opening 221 of the housing 22 is one, the end cap 23 can also be one, and one electrode terminal 26 can be provided in the end cap 23. The electrode terminal 26 is electrically connected to one of the positive electrode tab and the negative electrode tab of the electrode assembly 21, and the other of the positive electrode tab and the negative electrode tab is electrically connected to the housing 22. The end cap 23 and the housing 22 can be insulatedly connected.

[0091] As Figure 3 shown, in some embodiments, the positive electrode tab and the negative electrode tab of the electrode assembly 21 are respectively located at both ends of the axial direction of the battery cell 20. The opening 221 of the housing 22 is two, and the two openings 221 are respectively located at both ends of the axial direction of the housing 22. The end cap 23 covers one of the openings 221, and the other opening 221 allows the power supply terminal 26 to pass through and be electrically connected to the tab 211. Among them, the electrode terminal 26 and the tab 211 are connected through a current collecting member to achieve the electrical connection between the electrode terminal 26 and the tab 211.

[0092] As Figure 5As shown, a pressure relief mechanism 231 may also be provided on the end cap 23. The pressure relief mechanism 231 is used to actuate to release the internal pressure or temperature of the battery cell 20 when the pressure or temperature inside the battery cell 20 reaches a threshold value. This threshold value design varies according to different design requirements. The threshold value may depend on one or several materials among the positive electrode sheet, negative electrode sheet, electrolyte, and separator in the battery cell 20. The pressure relief mechanism 231 may adopt forms such as an explosion-proof valve, explosion-proof sheet, gas valve, pressure relief valve, or safety valve, and may specifically adopt a pressure-sensitive or temperature-sensitive element or structure. That is, when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold value, the pressure relief mechanism 231 performs an action or a weak structure provided in the pressure relief mechanism 231 is damaged, thereby forming an opening 221 or a channel for releasing the internal pressure or temperature. Figure 5 The pressure relief mechanism 231 shown in Figure 5 is a weak part formed on the end cap 23 by means of scoring or the like.

[0093] The electrode assembly 21 may include a positive electrode sheet (not shown in the figure), a negative electrode sheet (not shown in the figure), and a separator (not shown in the figure). The electrode assembly 21 may be a wound structure formed by winding the positive electrode sheet, separator, and negative electrode sheet, or may be a stacked structure formed by stacking the positive electrode sheet, separator, and negative electrode sheet. The electrode assembly 21 further includes a positive electrode tab and a negative electrode tab. The positive electrode current collector in the positive electrode sheet that is not coated with the positive electrode active material layer may be used as the positive electrode tab, and the negative electrode current collector in the negative electrode sheet that is not coated with the negative electrode active material layer may be used as the negative electrode tab.

[0094] The first current collecting member 24 is used to connect the tab 211, and the tab 211 may be a positive electrode tab or a negative electrode tab. That is, the first current collecting member 24 may be used to connect the positive electrode tab of the electrode assembly 21, or the first current collecting member 24 may be used to connect the negative electrode tab of the electrode assembly 21. If the first current collecting member 24 is used to connect the positive electrode tab of the electrode assembly 21, after the second current collecting member 25 connects the first current collecting member 24 and the first limiting portion 222, the housing 22 is electrically connected to the positive electrode tab of the electrode assembly 21, and the housing 22 serves as the positive electrode output terminal of the battery cell 20, and the electrode terminal 26 at the other end of the housing 22 is electrically connected to the negative electrode tab of the electrode assembly 21 to form the negative electrode output terminal of the battery cell 20. If the first current collecting member 24 is used to connect the negative electrode tab of the electrode assembly 21, after the second current collecting member 25 connects the first current collecting member 24 and the first limiting portion 222, the housing 22 is electrically connected to the negative electrode tab of the electrode assembly 21, and the housing 22 serves as the negative electrode output terminal of the battery cell 20, and the electrode terminal 26 at the other end of the housing 22 is electrically connected to the positive electrode tab of the electrode assembly 21 to form the positive electrode output terminal of the battery cell 20.

[0095] Along the thickness direction X of the end cap, the tab 211 has a first tab 211 region (outer layer tab 211) that coincides with the first region 241 and a second tab 211 region (inner layer tab 211) that coincides with the second region 242. The first region 241 of the first current collector member 24 is a closed-loop structure surrounding the outer periphery of the second region 242. Then, along the circumferential direction of the battery cell 20, the first region 241 can be welded to the first tab 211 region at any position, and the second region 242 can be welded to the second tab 211 region at any position.

[0096] The second current collector member can be welded, bonded, or abutted to the first limiting portion 222, so that the tab 211 and the housing 22 are electrically connected through the first current collector member 24 and the second current collector member 25.

[0097] The first connecting member includes a first region 241 that overlaps with the first limiting portion 222 in the thickness direction X of the end cap and a second region 242 that does not overlap with the first limiting portion 222 in the thickness direction X of the end cap. The first region 241 can be welded to the tab 211 of the outer layer, and the second region 242 can be welded to the tab 211 of the inner layer. Therefore, the tabs 211 of both the inner layer and the outer layer can be connected to the first current collector member 24, enabling uniform current conduction, avoiding the problem of excessive local current flow due to the inability of the tabs 211 of the outer layer to be connected to the current collector member, thereby reducing the risk of severe polarization of the tabs 211 of the outer layer during the cyclic charge and discharge process, and thus reducing the risk of lithium deposition caused by polarization. In addition, since the first current collector member 24 and the second current collector member 25 are separately provided, the first current collector member 24 can be first connected to the tab 211 without being restricted by the structure of the housing 22, and then the first current collector member 24 and the first limiting portion 222 of the housing 22 can be connected through the second current collector member 25, thus conveniently realizing the connection between the electrode assembly 21 and the housing 22.

[0098] Please refer to Figure 5 In some embodiments, the second current collector member 25 includes a body portion 251 and a connecting portion 252; the body portion 251 is stacked with the first current collector member 24 in the thickness direction, and the body portion 251 is used to connect the side of the first current collector member 24 facing away from the electrode assembly 21; the connecting portion 252 is connected to the body portion 251, and a part of the connecting portion 252 extends to the side of the first limiting portion 222 in its protruding direction to realize the connection between the first current collector member 24 and the first limiting portion 222.

[0099] The body portion 251 and the connecting portion 252 can be integrally formed. The body portion 251 and the connecting portion 252 can also be separately provided and connected into an integral structure through connection methods such as welding and bonding.

[0100] In this embodiment, the thickness direction refers to the thickness direction X of the end cap. The body portion 251 is stacked with the first current collecting member 24 along the thickness direction. Along the thickness direction X of the end cap, the projection of the body portion 251 may completely overlap with the second region 242 of the first current collecting member 24. In other embodiments, along the thickness direction X of the end cap, a portion of the projection of the body portion 251 may overlap with the first region 241 of the first current collecting member 24, and another portion of the projection of the body portion 251 may overlap with the first region 241.

[0101] The side of the first limiting portion 222 along its protruding direction refers to the innermost side of the first limiting portion 222. Part of the connecting portion 252 can be welded, bonded or abutted to the innermost side of the first limiting portion 222 to achieve the connection between the second current collecting member 25 and the first limiting portion 222.

[0102] The main body 251 is stacked with the first current collecting member 24 in the thickness direction and electrically connected to the first current collecting member 24, thereby improving the current conduction capability of the battery cell 20. The connecting portion 252 partially extends to the side of the first limiting portion 222 in the direction of its protrusion, thereby connecting the first current collecting member 24 and the first limiting portion 222. This increases the contact area between the second current collecting member 25 and the first limiting portion 222, thereby increasing the flow area between the housing 22 and the second current collecting member 25.

[0103] Please refer to Figure 5 、 Figure 6 、 Figure 7 , Figure 6 An axonometric view of the second current collecting member 25 provided in some embodiments of the present application, Figure 7 for Figure 6 2 is a cross-sectional view of the second current collecting member 25 in FIG. In some embodiments, the connecting portion 252 includes a first connecting portion 2521 and a second connecting portion 2522; the first connecting portion 2521 is configured to abut against a side of the first limiting portion 222 located in the protruding direction thereof; the second connecting portion 2522 is connected to an end of the first connecting portion 2521 facing away from the main body 251 and is configured to abut against a side of the first limiting portion 222 facing away from the electrode assembly 21.

[0104] The first connecting portion 2521 is the portion where the main body portion 251 extends into the interior of the first limiting portion 222. The first connecting portion 2521 can be in abutment or welded to the innermost side of the first limiting portion 222 to achieve abutting connection. The second connecting portion 2522 is the portion that extends from the end of the first connecting portion 2521 departing from the main body portion 251 to the side of the first limiting portion 222 departing from the electrode assembly 21. The second connecting portion 2522 can be welded or abutted to the first limiting portion 222. The second limiting portion 224 abuts against the side of the first limiting portion 222 departing from the electrode assembly 21, such that the connecting portion 252 is hooked on the first limiting portion 222. Exemplarily, the first connecting portion 2521 is a cylindrical structure, and the second connecting portion 2522 is an annular structure disposed at the end of the first connecting portion 2521 away from the main body portion 251. The second connecting portion 2522 can be welded to the first limiting portion 222 by penetration welding.

[0105] The first connecting portion 2521 and the second connecting portion 2522 can be integrally formed. For example, the second connecting portion 2522 is a flanging structure formed by folding the connecting portion 252. The first connecting portion 2521 and the second connecting portion 2522 can also be separately provided and connected into an integral structure by connection means such as welding and bonding.

[0106] As Figure 8 、 Figure 9 shown, Figure 8 is a cross-sectional view of the battery cell 20 provided by some other embodiments of the present application, Figure 9 and Figure 8 is an enlarged view of II in

[0107] Please refer to Figure 9 、 Figure 10 、 Figure 11 together, Figure 10 is a schematic structural view of the second current collector member 25 provided by some other embodiments of the present application, Figure 11 and Figure 10sectional view of the second current collecting member 25 in FIG. In some embodiments, the edge of the body portion 251 may radially extend beyond the outer circumferential surface of the first connecting portion 2521, so that the body portion 251 includes a first body portion 2511 surrounding the outer circumference of the first connecting portion 2521 and a second body portion 2512 located within the first connecting portion 2521. Along the thickness direction X of the end cap, the projection of the first body portion 2511 coincides with the first region 241 of the first current collecting member 24, and the projection of the second body portion 2512 coincides with the second region 242 of the first current collecting member 24. Therefore, a portion of the projection of the body portion 251 along the thickness direction X of the end cap coincides with the first region 241 of the first current collecting member 24, and another portion of the projection of the body portion 251 may coincide with the first region 241.

[0108] The first connecting portion 2521 abuts against the side of the first limiting portion 222 located in its protruding direction, and the second connecting portion 2522 abuts against the side of the first limiting portion 222 facing away from the electrode assembly 21, thereby improving the connection stability between the connecting portion 252 and the first limiting portion 222, and can also increase the contact area between the second current collecting component 25 and the first limiting portion 222, so as to increase the flow area between the shell 22 and the second current collecting component 25.

[0109] In some embodiments, the first connection portion 2521 extends along the thickness direction (see Figure 5 and Figure 9 ).

[0110] The first connection portion 2521 is perpendicularly connected to the main body 251. In other embodiments, the first connection portion 2521 may extend in other directions. For example, if the first connection portion 2521 is arranged at an acute angle to the main body 251, the first connection portion 2521 may extend in a direction forming an acute angle with the thickness direction X of the end cap until it abuts against the innermost side surface of the first limiting portion 222, or the first connection portion 2521 may bend at a certain angle and then abut against the first limiting portion 222.

[0111] The first connecting portion 2521 extends along the thickness direction X of the end cover so that the distance between the first extension portion and the first limiting portion 222 on the protruding side thereof is the shortest, thereby reducing the internal space of the battery cell 20 occupied by the first connecting portion 2521 .

[0112] Please refer to Figure 6 In some embodiments, the first connecting portion 2521 is a closed loop structure extending circumferentially along the shell 22 .

[0113] Exemplarily, the first connecting portion 2521 is a cylindrical structure, and the first connecting portion 2521 is coaxially arranged with the electrode assembly 21. The second connecting portion 2522 is connected to one end of the first connecting portion 2521 facing away from the body portion 251. The first connecting portion 2521 extends beyond the outer peripheral surface of the first connecting portion 2521 in a direction perpendicular to the axial direction of the first connecting portion 2521 and extends to the side of the first limiting portion 222 facing away from the electrode assembly 21. Among them, the outer peripheral surface of the first connecting portion 2521 is the surface of the first connecting portion 2521 that radially moves away from its central axis.

[0114] In other embodiments, the first connecting portion 2521 may also be a non-closed-loop structure. For example, the first connecting portion 2521 is C-shaped.

[0115] The first connecting portion 2521 is a closed-loop structure, which can increase the contact area between the first connecting portion 2521 and the first limiting portion 222, thereby increasing the current-carrying area between the housing 22 and the second current collecting member 25.

[0116] Please continue to refer to Figure 6 In some embodiments, the second connecting portion 2522 is a closed-loop structure surrounding the edge of the first connecting portion 2521.

[0117] In other embodiments, the second connecting portion 2522 may also be a non-closed-loop structure. For example, the second connecting portion 2522 is C-shaped.

[0118] The second connecting portion 2522 is a closed-loop structure, which can increase the contact area between the second connecting portion 2522 and the first limiting portion 222, thereby increasing the current-carrying area between the housing 22 and the second current collecting member 25.

[0119] As Figure 12 、 Figure 13 shown, Figure 12 FIG. Figure 13 FIG.

[0120] To enable the first current collecting member 24 and the second current collecting member 25 to form a plug-in fit, one of the first current collecting member 24 and the second current collecting member 25 is provided with a groove 243, and the other of the first current collecting member 24 and the second current collecting member 25 may be provided with a protrusion that can be inserted into the groove 243. The groove 243 and the protrusion form a plug-in positioning fit.

[0121] The first current collector member 24 and the second current collector member 25 form a plug-in fit along the thickness direction X of the end cap, so that the first current collector member 24 and the second current collector member 25 can be plugged and positioned, which can improve the stability of the relative position relationship between the first current collector member 24 and the second current collector member 25, facilitate the welding of the first current collector member 24 and the second current collector member 25, and improve the stability of power output.

[0122] Please continue to refer to Figure 12 、 Figure 13 In some embodiments, a groove 243 is formed on one side of the first current collector member 24 facing the end cap 23, and a part of the second current collector member 25 is received in the groove 243.

[0123] A part of the second current collector member 25 is received in the groove 243. A part or all of the body portion 251 of the second current collector member 25 in the thickness direction X of the end cap can be received in the groove 243, or all of the body portion 251 and a part of the connecting portion 252 of the second current collector member 25 can be received in the groove 243. The inner diameter of the groove 243 is the same as the outer diameter of the body portion 251.

[0124] In other embodiments, a protrusion that cooperates with the groove 243 on the first current collector member 24 can also be provided separately on the second current collector member 25, and the second current collector member 25 itself is located outside the groove 243.

[0125] In other embodiments, the groove 243 can also be provided on one side of the body portion 251 of the second current collector member 25 facing the first current collector member 24, and a part or all of the second current collector member 25 is received in the groove 243.

[0126] The second current collector is plugged into the groove 243 on one side of the first current collector member 24 facing the end cap 23, which not only enables the first current collector member 24 and the second current collector member 25 to be plugged and positioned, improves the stability of the relative position relationship between the first current collector member 24 and the second current collector member 25, facilitates the welding of the first current collector member 24 and the second current collector member 25, and improves the stability of power output; but also reduces the space occupied by the first current collector member 24 and the second current collector member 25 in the thickness direction X of the end cap. And the position of the first current collector member 24 where the groove 243 is provided has a smaller thickness, which is convenient for welding the first current collector member 24 and the tab 211.

[0127] Please refer to Figure 14 , Figure 14 This is a schematic structural diagram of the first current collector provided in some embodiments of the present application. In some embodiments, the first current collector member 24 is provided with a central hole 244 that penetrates the first current collector member 24 along the thickness direction, and a diversion groove 245 is formed on one side of the first current collector member 24 facing the electrode assembly 21. The diversion groove 245 is configured to guide the electrolyte entering the electrode assembly 21 through the central hole 244 to the periphery.

[0128] The flow guiding groove 245 communicates with the central hole 244 and penetrates through the outer edge of the first current collecting member 24 along the radial direction of the central hole 244. The central hole 244 is coaxially arranged with the battery cell 20. To facilitate the electrolyte to enter the central hole 244, the second current collecting member 25 is also provided with a through hole 2513 coaxially arranged with the first current collecting member 24, and the through hole 2513 is arranged in the body portion 251 of the second current collecting member 25.

[0129] The guiding grooves can be arranged in different forms on the side of the first current collecting member 24 facing the electrode assembly 21, such as being arranged radially, in a cross shape, etc.

[0130] As Figure 15 shown, Figure 15 is a schematic structural diagram of the electrode assembly 21 provided by some embodiments of the present application. After the tab 211 of the electrode assembly 21 is flattened, a recessed portion 212 is formed. The recessed portion 212 is used for the electrolyte to flow through. The tab 211 in the area other than the recessed portion 212 is used for welding with the first current collecting member 24, that is, the area where the welding mark is formed is defined as the first welding mark area 213. The area outside the groove 243 on the side of the first current collecting member 24 facing the electrode assembly 21 (defined as the second welding mark area 246) is used for welding with the area where the welding mark of the tab 2l1 is formed. As Figure 16 shown, after welding, the notch of the flow guiding groove 245 of the first current collecting member 24 is oppositely arranged with the notch of the recessed portion 212 of the tab 211, and the flow guiding groove 245 of the first current collecting member 24 and the recessed portion 212 of the tab 211 jointly define a space for the electrolyte to flow through. In some other embodiments, the flattened tab 211 may not be provided with the recessed portion 212. The first welding area and the second welding mark area 246 can be welded by laser sweeping, and the depth of laser sweeping should be less than the sum of the depth of the relative recessed portion 212 and the depth of the flow guiding groove 245 to ensure good wetting of the electrode assembly 21 by the electrolyte.

[0131] In some other embodiments, the flattened tab 211 may not be provided with the recessed portion 212. When welding the tab 211 and the first current collecting member 24 by laser sweeping, the depth of laser sweeping should be less than the depth of the flow guiding groove 245 to ensure good wetting of the electrode assembly 21 by the electrolyte.

[0132] The flow guiding groove 245 can guide the electrolyte in the central hole 244 to the area outside the central hole 244, so that the electrolyte is evenly distributed inside the battery cell 20, thereby fully and evenly wetting the electrode assembly 21 and reducing the possibility of lithium deposition in the battery cell 20.

[0133] Please refer to Figure 5 、 Figure 9, in some embodiments, a first recess 223 is formed on the housing 22 and recesses inward from the outer peripheral wall of the housing 22, and a first limiting portion 222 protruding from the inner peripheral wall of the housing 22 is formed at a position corresponding to the first recess 223 on the housing 22. Both the first recess 223 and the first limiting portion 222 are annular structures.

[0134] Please refer to Figure 5 and Figure 9 , the first limiting portion 222 includes a first connecting section 2221, a second connecting section 2222, and a third connecting section 2223 that are sequentially connected. One end of the first connecting section 2221 facing away from the second connecting section 2222 is connected to the housing 22, and one end of the third connecting section 2223 facing away from the second connecting section 2222 is connected to the housing 22. Along the thickness direction X of the end cap, the first connecting section 2221 and the third connecting section 2223 are oppositely arranged. The first connecting section 2221 is relatively closer to the electrode assembly 21 than the third connecting section 2223. The outer surface of the first connecting section 2221, the outer surface of the second connecting section 2222, and the outer surface of the third connecting section 2223 together define the first recess 223. Among them, the outer surfaces of the first connecting section 2221, the second connecting section 2222, and the third connecting section 2223 all refer to the exposed surfaces of the first connecting section 2221, the second connecting section 2222, and the third connecting section 2223.

[0135] In some embodiments, the first connecting section 2221 and the second connecting section 2222 are in arc transition, and the second connecting section 2222 and the third connecting section 2223 are in arc transition, avoiding the formation of edges at the connection positions of the first connecting portion 2521 and the second connecting section 2222 and the connection position of the second connecting section 2222 and the third connecting section 2223 from scratching the internal structure of the housing 22.

[0136] In some other embodiments, the first limiting portion 222 may also be a protrusion provided on the inner peripheral surface of the housing 22.

[0137] Forming the first limiting portion 222 on the inner wall of the housing 22 is more difficult, while the difficulty of forming the first recess 223 on the outer peripheral wall of the housing 22 is lower than that of directly forming the first limiting portion 222 on the inner peripheral wall of the housing 22. Therefore, by forming the first limiting portion 222 protruding from the inner peripheral wall of the housing 22 at a position corresponding to the first recess 223 on the housing 22, the forming difficulty of the first limiting portion 222 is reduced.

[0138] Please continue to refer to Figure 5 and Figure 9 , in some embodiments, the housing 22 has a second limiting portion 224; in the thickness direction X of the end cap, the second limiting portion 224 and the first limiting portion 222 are used to jointly limit the movement of the end cap 23 relative to the housing 22 in the thickness direction.

[0139] The first limiting part 222 is an annular structure, and the edge of the end cover 23 is inserted into the space formed by the first limiting part 222 and the second limiting part 224.

[0140] The second limiting part 224 and the first limiting part 222 cooperate to jointly limit the movement of the end cover 23 relative to the housing 22 in the thickness direction X of the end cover, so that the end cover 23 and the housing 22 maintain a stable connection relationship.

[0141] In some embodiments, the second limiting part 224 is a flanging structure formed by inwards folding of the housing 22 at the opening 221 position. It can be understood that the second limiting part 224 is a part of the housing 22, which can reduce the connection relationship on the housing 22 and improve the sealing performance and structural strength of the housing 22. In other embodiments, the second limiting part 224 and the housing 22 can also be two separately arranged structures, and the second limiting part 224 is connected to the opening 221 end of the housing 22 by means of welding or the like.

[0142] The second limiting part 224 is a flanging structure formed by inwards folding of the housing 22 at the opening 221 position, so that the second limiting part 224 can stably limit the end cover 23 on the side of the end cover 23 facing away from the electrode assembly 21. And the second limiting part 224 is a part of the housing 22, which can also reduce the connection relationship of the housing 22, thereby improving the structural strength of the housing 22.

[0143] Please continue to refer to Figure 5 and Figure 9 In some embodiments, the battery cell 20 further includes a seal 27, and the seal 27 seals between the first limiting part 222 and the end cover 23 and between the second limiting part 224 and the end cover 23.

[0144] The seal 27 includes a first seal part 271, a second seal part 272 and a third seal part 273 which are connected in sequence. The first part 12 seals between the side of the first limiting part 222 facing away from the electrode assembly 21 and the side of the end cover 23 facing the electrode assembly 21. The second seal part 272 seals between the inner peripheral surface of the housing 22 and the outer peripheral surface of the end cover 23. The third seal part 273 seals between the side of the second limiting part 224 facing the electrode assembly 21 and the side of the end cover 23 facing away from the electrode assembly 21.

[0145] By sealing the seal 27 between the first limiting part 222 and the end cover 23 and between the second limiting part 224 and the end cover 23, the sealing performance of the battery cell 20 is improved.

[0146] The embodiment of the present application further provides a battery 100, and the battery 100 includes the battery cell 20 provided in any one of the above embodiments.

[0147] The battery cell 20 includes a first current collector member 24 and a second current collector member 25. The first current collector member 24 is connected to the tab 211, and the second current collector member 25 connects the first current collector member 24 and the first limiting portion 222 of the housing 22. The first region 241 of the first member can be welded to the tab 211 of the outer layer, and the second region 242 of the first member can be welded to the tab 211 of the inner layer. Therefore, the tabs 211 of both the inner layer and the outer layer can be connected to the first current collector member 24, enabling uniform current conduction, avoiding the problem of excessive local overcurrent due to the inability of the tabs 211 of the outer layer to be connected to the current collector member, thereby reducing the risk of severe polarization of the tabs 211 of the outer layer during the cyclic charge and discharge process, reducing the risk of lithium deposition caused by polarization, and improving the safety performance of the battery 100.

[0148] The embodiment of the present application also provides an electrical device, which uses the battery 100 provided in the above embodiment.

[0149] The battery 100 will not have the problem of excessive local overcurrent due to the inability of the outer tabs 211 to be connected to the current collector member, thereby reducing the risk of severe polarization of the outer tabs 211 during the cyclic charge and discharge process, reducing the risk of lithium deposition, and improving the electrical safety of the electrical device.

[0150] As Figure 17 shown, the embodiment of the present application provides a manufacturing device 2000 for a battery cell. The manufacturing device 2000 for a battery cell includes a providing device 2100 and an assembling device 2200; the providing device 2100 is configured to provide an electrode assembly 21, a housing 22, an end cap 23, a first current collector member 24, and a second current collector member 25. The electrode assembly 21 has tabs 211; the housing 22 has an opening 221, and the housing 22 is used to accommodate the electrode assembly 21. A first limiting portion 222 is convexly provided on the inner side surface of the housing 22, and the first limiting portion 222 is used to limit the movement of the end cap 23 in the direction close to the electrode assembly 21; the end cap 23 is used to cover the opening 221; the assembling device 2200 is configured to accommodate the electrode assembly 21 in the housing 22, connect the first current collector member 24 to the tabs 211, connect the second current collector member 25 to the first current collector member 24 and the first limiting portion 222, and seal the end cap 23 on the opening 221; wherein, the first current collector member 24 includes a first region 241 that overlaps with the first limiting portion 222 along the thickness direction X of the end cap and a second region 242 that does not overlap with the first limiting portion 222 along the thickness direction. Both the first region 241 and the second region 242 are welded to the tabs 211.

[0151] As Figure 18 shown, the embodiment of the present application also provides a manufacturing method for a battery cell 20. The manufacturing method includes:

[0152] S100, provide an electrode assembly 21, a housing 22, an end cap 23, a first current collector member 24 and a second current collector member 25. The electrode assembly 21 has a tab 211; the housing 22 has an opening 221. The housing 22 is used to accommodate the electrode assembly 21. A first limiting portion 222 is convexly provided on the inner side surface of the housing 22. The first limiting portion 222 is used to limit the movement of the end cap 23 in the direction approaching the electrode assembly 21;

[0153] S200, connect the first current collector member 24 to the tab 211;

[0154] S300, connect the second current collector member 25 to the first current collector member 24;

[0155] S400, accommodate the electrode assembly 21 in the housing 22 and connect the second current collector member 25 to the first limiting portion 222;

[0156] S500, seal the end cap 23 on the opening 221;

[0157] Wherein, the first current collector member 24 includes a first region 241 that overlaps with the first limiting portion 222 along the thickness direction X of the end cap and a second region 242 that does not overlap with the first limiting portion 222 along the thickness direction. Both the first region 241 and the second region 242 are welded to the tab 211.

[0158] The embodiment of the present application provides a cylindrical battery cell 20. The cylindrical battery cell 20 includes a housing 22, an end cap 23, an electrode assembly 21, a first current collector member 24 and a second current collector member 25; the electrode assembly 21 has a tab 211.

[0159] The housing 22 has an opening 221. The housing 22 is used to accommodate the electrode assembly 21. A first recess 223 that is recessed inward from the outer peripheral wall of the housing 22 is formed on the housing 22, and a first limiting portion 222 that protrudes from the inner peripheral wall of the housing 22 is formed at a position corresponding to the first recess 223 on the housing 22. Both the first recess 223 and the first limiting portion 222 are annular structures. The first limiting portion 222 is used to limit the movement of the end cover 23 in the direction approaching the electrode assembly 21. The battery cell 20 further includes a second limiting portion 224. The second limiting portion 224 is a flanging structure formed by inverting the opening 221 of the housing 22 inward. The second limiting portion 224 is used to limit the movement of the end cover 23 in the direction away from the electrode assembly 21. The end cover 23 is used to cover the opening 221; a first current collecting member 24, along the thickness direction X of the end cover, is located on the side of the first limiting portion 222 facing the electrode assembly 21. The first current collecting member 24 is used to connect the tab 211. The first current collecting member 24 includes a first region 241 that overlaps with the first limiting portion 222 along the thickness direction X of the end cover and a second region 242 that does not overlap with the first limiting portion 222 along the thickness direction. Both the first region 241 and the second region 242 are welded to the tab 211. A second current collecting member 25 is located on the side of the first current collecting member 24 away from the electrode assembly 21 along the thickness direction X of the end cover. The second current collecting member 25 is used to connect the first current collecting member 24 and the first limiting portion 222, so as to electrically connect the tab 211 and the housing 22.

[0160] The tabs 211 in the inner layer and the tabs 211 in the outer layer of the battery cell 20 can both be connected to the first current collecting member 24, which can achieve uniform current conduction, avoid the problem of excessive local overcurrent due to the inability of the tabs 211 in the outer layer to be connected to the current collecting member, thereby reducing the risk of serious polarization of the tabs 211 in the outer layer during the cyclic charge and discharge process, and thus reducing the risk of lithium deposition caused by polarization.

[0161] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that, Comprising: An electrode assembly having tabs; A housing having an opening, the housing being configured to accommodate the electrode assembly, and a first limiting portion being convexly provided on an inner side surface of the housing; An end cap for covering the opening, the first limiting portion being configured to limit the end cap from moving in a direction approaching the electrode assembly; A first current collecting member located on a side of the first limiting portion facing the electrode assembly along a thickness direction of the end cap, the first current collecting member being configured to connect the tabs; And A second current collecting member located on a side of the first current collecting member facing away from the electrode assembly along the thickness direction, the second current collecting member being configured to connect the first current collecting member and the first limiting portion; Wherein, the first current collecting member includes a first region overlapping with the first limiting portion along the thickness direction and a second region not overlapping with the first limiting portion along the thickness direction, and both the first region and the second region are welded to the tabs.

2. The battery cell according to claim 1, wherein The second current collecting member includes: A body portion stacked with the first current collecting member along the thickness direction, the body portion being configured to connect a side of the first current collecting member facing away from the electrode assembly; and A connecting portion connected to the body portion, a part of the connecting portion extending to a side of the first limiting portion in a protruding direction thereof to achieve connection between the first current collecting member and the first limiting portion.

3. The battery cell according to claim 2, wherein The connecting portion includes: A first connecting portion configured to abut against a side of the first limiting portion in a protruding direction thereof; A second connecting portion connected to an end of the first connecting portion facing away from the body portion, the second connecting portion being configured to abut against a side of the first limiting portion facing away from the electrode assembly.

4. The battery cell according to claim 3, characterized in that, The first connecting portion extends along the thickness direction.

5. The battery cell according to claim 3, wherein, The first connecting portion is a closed-loop structure extending along a circumference of the housing.

6. The battery cell according to claim 5, characterized in that, The second connecting portion is a closed-loop structure surrounding an edge of the first connecting portion.

7. The battery cell according to claim 1, characterized in that, The first current collecting member and the second current collecting member form a plug-in fit along the thickness direction.

8. The battery cell according to claim 7, wherein, A groove is formed on a side of the first current collecting member facing the end cap, and a part of the second current collecting member is received in the groove.

9. The battery cell according to any one of claims 1-8, characterized in that, The first current collecting member is provided with a central hole penetrating through the first current collecting member along the thickness direction and a flow guiding groove is formed on a side of the first current collecting member facing the electrode assembly, and the flow guiding groove is configured to guide electrolyte entering the electrode assembly through the central hole to the outer periphery.

10. The battery cell according to any one of claims 1-8, characterized in that, A first recess is formed on an outer peripheral wall of the housing and recessed inwardly, and the first limiting portion protruding from an inner peripheral wall of the housing is formed at a position corresponding to the first recess on the housing, and both the first recess and the first limiting portion are annular structures.

11. The battery cell according to any one of claims 1-8, characterized in that, The housing has a second limiting portion; In a thickness direction of the end cap, the second limiting portion and the first limiting portion are configured to jointly limit the end cap from moving relative to the housing in the thickness direction.

12. The battery cell according to claim 11, wherein, The second limiting portion is a flanging structure formed by inverting the housing at the opening position.

13. The battery cell according to claim 11, wherein The battery cell further includes a sealing member, and the sealing member seals between the first limiting portion and the end cap and between the second limiting portion and the end cap.

14. A battery, characterized in that, Comprising a battery cell according to any one of claims 1-13.

15. An electrical device, characterized in that, Comprising a battery according to claim 14.

16. A manufacturing device for a battery cell, characterized in that, Comprising: A providing device configured to provide an electrode assembly, a housing, an end cap, a first current collector member, and a second current collector member, the electrode assembly having a tab; the housing having an opening, the housing being for accommodating the electrode assembly, an inner side surface of the housing being convexly provided with a first limiting portion for restricting the end cap from moving in a direction close to the electrode assembly; the end cap being for covering the opening; An assembling device configured to accommodate the electrode assembly in the housing, connect the first current collector member to the tab, connect the second current collector member to the first current collector member and the first limiting portion, and seal the end cap on the opening; Wherein, the first current collector member includes a first region overlapping with the first limiting portion in a thickness direction of the end cap and a second region not overlapping with the first limiting portion in the thickness direction, and both the first region and the second region are welded to the tab.

17. A manufacturing method of a battery cell, characterized in that Comprising: Providing an electrode assembly, a housing, an end cap, a first current collector member, and a second current collector member, the electrode assembly having a tab; the housing having an opening, the housing being for accommodating the electrode assembly, an inner side surface of the housing being convexly provided with a first limiting portion for restricting the end cap from moving in a direction close to the electrode assembly; Connecting the first current collector member to the tab; Connecting the second current collector member to the first current collector member; Accommodating the electrode assembly in the housing and connecting the second current collector member to the first limiting portion; Sealing the end cap on the opening; Wherein, the first current collector member includes a first region overlapping with the first limiting portion in a thickness direction of the end cap and a second region not overlapping with the first limiting portion in the thickness direction, and both the first region and the second region are welded to the tab.

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