Battery cell, battery, electrical device, preparation method and device for battery cell

Abstract

The present application relates to a battery cell, a battery, an electrical device, a preparation method and device of the battery cell. The battery cell includes: a housing including a wall portion, and an electrode lead-out hole is provided on the wall portion; an electrode assembly disposed inside the housing, and a first tab is formed at one end of the electrode assembly facing the wall portion; an electrode terminal including a terminal body and a first flange, the terminal body penetrates through the electrode lead-out hole, the first flange protrudes radially outwards from the outer peripheral surface of the terminal body, and the first flange is located inside the wall portion to limit the movement of the electrode terminal in a direction away from the electrode assembly; a first current collecting member located between the wall portion and the electrode assembly for connecting the electrode terminal and the first tab; wherein, the terminal body has a first end face facing the first current collecting member, a groove and a connection area for connecting with the first current collecting member are provided on the first end face, and the groove is located between the connection area and the first flange.

Description

Technical Field

[0001] This application relates to the technical field of batteries. Specifically, it relates to a battery cell, a battery, an electrical device, a preparation method and device for a battery cell. Background Art

[0002] In the context of the pursuit of energy conservation and emission reduction, batteries are widely used in electrical devices such as mobile phones, computers, electric vehicles, etc. The batteries provide electrical energy for the electrical devices. The overcurrent capacity and service life of the battery are positively correlated with the performance of the electrical device. How to improve the overcurrent capacity and service life of the battery is an important research and development direction in this field. Summary of the Invention

[0003] This application aims to provide a battery cell, a battery, an electrical device, a preparation method and device for a battery cell to solve the problem of improving the overcurrent capacity and service life of the battery.

[0004] The embodiments of this application are implemented as follows:

[0005] In a first aspect, an embodiment of this application provides a battery cell, which includes: a housing including a wall portion, and the wall portion is provided with an electrode lead-out hole; an electrode assembly disposed inside the housing, and a first tab is formed at one end of the electrode assembly facing the wall portion; an electrode terminal including a terminal body and a first flange, the terminal body passes through the electrode lead-out hole, the first flange protrudes radially from the outer peripheral surface of the terminal body along the terminal body, and the first flange is located inside the wall portion to limit the movement of the electrode terminal in a direction away from the electrode assembly; a first current collector member located between the wall portion and the electrode assembly for connecting the electrode terminal and the first tab; wherein, the terminal body has a first end face facing the first current collector member, the first end face is provided with a groove and a connection area for connecting with the first current collector member, and the groove is located between the connection area and the first flange.

[0006] In the technical solution provided by this application, a groove is provided between the connection area and the first flange. The groove can release the stress received by the first flange, avoid the stress received by the first flange being transmitted to the connection area and causing deformation of the connection area, ensure the flatness of the connection area, and further improve the connection reliability between the connection area and the first current collector member, avoid the connection failure between the electrode terminal and the first current collector member, prevent the internal circuit of the battery cell from being disconnected, ensure stable overcurrent between the electrode terminal and the first current collector member, and improve the overcurrent capacity and service life of the battery cell.

[0007] In an embodiment of this application, the groove is an annular groove surrounding the connection area.

[0008] In the above technical solution, the groove surrounds the connection area, or in other words, the groove encloses on the first end surface, and the area enclosed by the groove forms the connection area to limit the stress in any direction from being transmitted to the connection area and ensure the flatness of the connection area.

[0009] In an embodiment of the present application, the electrode assembly is of a wound structure, and the first current collector member covers the winding center hole of the electrode assembly.

[0010] In the above technical solution, the position of the first current collector member for connecting to the connection area is exposed in the winding center hole. A welding tool can pass through the winding center hole to weld the first current collector member to the connection area, so that the welding mark is located inside the battery cell, preventing the welding mark from being exposed outside and preventing the welding mark from being oxidized and rusted by the outside air, thereby improving the service life of the battery.

[0011] In an embodiment of the present application, the first current collector member includes a current collector body and a convex portion. The convex portion protrudes from the current collector body in the direction towards the electrode terminal. The convex portion corresponds to the position of the winding center hole of the electrode assembly and is used to connect the connection area, and the current collector body is used to connect the first tab.

[0012] In the above technical solution, by providing the convex portion that is higher than the current collector body, interference between the current collector body and structures other than the connection area of the electrode terminal is prevented, ensuring that the convex portion is in close contact with the connection area. Moreover, force can be applied or welding can be performed on the convex portion through the winding center hole, so that the convex portion is tightly connected to the connection area, further improving the connection strength and connection area between the first current collector member and the connection area, achieving stable current conduction, and improving the current-carrying capacity and service life of the battery.

[0013] In an embodiment of the present application, the outer diameter of the groove is greater than the diameter of the convex portion.

[0014] The outer diameter of the groove refers to the diameter of the outer groove wall. In the above technical solution, along the central axis direction of the terminal body, the projection of the convex portion on the first end surface falls within the area enclosed by the outer groove wall, so as to prevent interference between the convex portion and structures other than the connection area and ensure that there is no gap between the convex portion and the connection area and they are in close connection.

[0015] In an embodiment of the present application, the inner diameter of the groove is smaller than the diameter of the convex portion.

[0016] In the above technical solution, the inner diameter of the groove refers to the diameter of the inner groove wall. By making the diameter of the inner groove wall of the groove smaller than the diameter of the convex portion, it is ensured that the connection area is completely covered by the convex portion, maximizing the utilization of the connection area and maximizing the current-carrying area.

[0017] In an embodiment of the present application, the convex portion includes an end wall and a peripheral wall. The peripheral wall surrounds the end wall, the peripheral wall is connected to the current collector body, the end wall is connected to the connection area, and the peripheral wall and the end wall together enclose a concave cavity.

[0018] In the above technical solution, by setting the surface of the convex portion facing away from the wall portion as a concave cavity, the concave cavity marks the position of the convex portion on the surface of the first current collector member facing away from the wall portion, so as to facilitate welding the end wall and the connection area from the side of the first current collector member facing away from the wall portion. The concave cavity is also used to position the welding head to prevent the welding head from deviating, ensuring a stable connection between the convex portion and the connection area. Compared with the case where no concave cavity is provided on the back surface of the convex portion, by providing the concave cavity, the thickness at the end wall is also reduced, facilitating penetration welding.

[0019] In an embodiment of the present application, the diameter of the concave cavity is greater than the diameter of the winding center hole.

[0020] In the above technical solution, one end of the winding center hole is completely covered by the concave cavity, and the welding head will not interfere with the current collector body after passing through the winding center hole, and the welding head can smoothly enter the concave cavity to weld the end wall and the connection area. And when the diameter of the concave cavity is fixed, by reducing the diameter of the winding center hole of the electrode assembly to be less than the diameter of the concave cavity, the space occupancy ratio of the electrode assembly can be increased, improving the energy density of the battery cell.

[0021] In an embodiment of the present application, a slope is formed on the side of the electrode terminal facing the first current collector member. The slope is inclined with respect to a plane perpendicular to the central axis direction of the electrode terminal and extends from the outer groove wall of the groove towards the direction close to the electrode assembly.

[0022] In the above technical solution, by providing a slope on the periphery of the outer groove wall of the groove to avoid the first current collector member and guide the first current collector member to move towards the connection area, so as to accurately position the first current collector member and ensure that the first current collector member is connected to the connection area.

[0023] In an embodiment of the present application, the electrode terminal further includes a second flange. The second flange protrudes radially from the outer peripheral surface of the terminal body along the radial direction of the terminal body. The second flange is located outside the wall portion to limit the movement of the electrode terminal in the direction towards the electrode assembly.

[0024] In the above technical solution, under the combined action of the first flange and the second flange, the movement of the electrode terminal along the central axis of the terminal body is restricted, so that the electrode terminal is axially positioned to prevent the electrode terminal from shaking axially, further ensuring a stable connection between the electrode terminal and the first current collector member.

[0025] In an embodiment of the present application, the battery cell further includes an insulating member disposed between the electrode terminal and the wall portion to insulatively isolate the electrode terminal and the wall portion.

[0026] In the above technical solution, by providing the insulating member, the wall portion is prevented from being electrified, the short - circuit risk is reduced, and thus the safety and service life of the battery cell are improved.

[0027] In an embodiment of the present application, an annular protrusion is formed on a side of the second flange facing the wall portion. The annular protrusion is disposed around the central axis of the electrode terminal, and the annular protrusion is configured to squeeze a portion of the insulating member between the second flange and the wall portion.

[0028] In the above technical solution, by squeezing the insulating member with the annular protrusion, an annular sealing area is formed between the second flange and the wall portion to prevent liquid leakage from the gap between the electrode terminal and the wall portion, and the service life of the battery cell is improved.

[0029] In an embodiment of the present application, along the thickness direction of the wall portion, a projection of the first flange on the second flange covers the annular protrusion.

[0030] In the above technical solution, the first flange supports on the inner side of the wall portion to prevent the wall portion from being deformed by the extrusion of the outer annular protrusion. The wall portion and the annular protrusion cooperate to squeeze the insulating member, eliminating the gap between the electrode terminal and the wall portion and improving the sealing effect.

[0031] In an embodiment of the present application, the outer shell includes a housing and an end cap. The housing includes a bottom wall and a side wall. The side wall surrounds the bottom wall. One end of the side wall is connected to the bottom wall, and the other end of the side wall encloses an opening opposite to the bottom wall. The end cap covers the opening, and the wall portion is the bottom wall or the end cap.

[0032] In the above technical solution, the wall portion can be the end cap, or the wall portion can be the bottom wall of the housing. Whether the electrode terminal is disposed on the end cap or the bottom wall of the housing, the flatness of the connection area can be ensured.

[0033] In an embodiment of the present application, the electrode terminal is insulated from the wall portion. A second tab is formed at an end of the electrode assembly away from the wall portion, and the second tab has a polarity opposite to that of the first tab;

[0034] The battery cell further includes a second current - collecting member for electrically connecting the second tab and the wall portion.

[0035] In the above technical solution, the electrode terminal and the wall portion are located at the same end of the battery cell, and the electrode terminal and the wall portion carry opposite charges. Therefore, current collecting members with opposite polarities can be connected at the same end of the battery cell, which is convenient for assembly and connection.

[0036] In a second aspect, an embodiment of the present application provides a battery, which includes the aforementioned battery cell.

[0037] In a third aspect, an embodiment of the present application provides an electrical device, which includes the aforementioned battery.

[0038] In a fourth aspect, an embodiment of the present application provides a method for manufacturing a battery cell, which includes: providing an electrode assembly, with a first tab formed at one end of the electrode assembly; providing a housing and an electrode terminal, where the housing includes a bottom wall and a side wall, the side wall surrounds the bottom wall, one end of the side wall is connected to the bottom wall, the other end of the side wall encloses an opening opposite to the bottom wall, the bottom wall is provided with an electrode lead-out hole, the electrode terminal includes a terminal body and a first flange, the terminal body passes through the electrode lead-out hole, the first flange protrudes radially from the outer peripheral surface of the terminal body, the first flange is located inside the bottom wall to limit the movement of the electrode terminal in a direction away from the electrode assembly, the terminal body has a first end face facing the inside of the housing, and the first end face is provided with a groove and a connection area, the groove is located between the connection area and the first flange; providing a first current collecting member, connecting the first current collecting member to the first tab; placing the electrode assembly and the first current collecting member into the housing, and making the first current collecting member located between the bottom wall and the electrode assembly; connecting the first current collecting member to the connection area; providing an end cap, and covering the opening of the housing with the end cap.

[0039] In an embodiment of the present application, the step of connecting the first current collecting member to the first tab is completed before the step of placing the electrode assembly into the housing.

[0040] In the above technical solution, after the first current collecting member is connected to the electrode assembly as a whole and then put into the housing, it ensures the stable connection between the first current collecting member and the first tab, and improves the current-carrying capacity of the battery cell.

[0041] In an embodiment of the present application, the step of connecting the first current collecting member to the connection area includes: entering the welding unit into the housing through the opening and passing through the winding center hole of the electrode assembly to weld the first current collecting member and the connection area.

[0042] In the above technical solution, the welding mark between the first current collecting member and the electrode terminal is located inside the battery cell, and the welding mark does not contact the external air, is not easily oxidized and rusted, and improves the service life of the battery.

[0043] In a fifth aspect, an embodiment of the present application provides a preparation device for a battery cell, which includes: a first providing device for providing an electrode assembly, with a first tab formed at one end of the electrode assembly; a second providing device for providing a housing and an electrode terminal, the housing including a bottom wall and a side wall, the side wall surrounding the bottom wall, one end of the side wall being connected to the bottom wall, the other end of the side wall enclosing an opening opposite to the bottom wall, the bottom wall being provided with an electrode lead-out hole, the electrode terminal including a terminal body and a first flange, the terminal body passing through the electrode lead-out hole, the first flange protruding radially from the outer peripheral surface of the terminal body, the first flange being located inside the bottom wall to limit the movement of the electrode terminal in a direction away from the electrode assembly, the terminal body having a first end face facing the inside of the housing, the first end face being provided with a groove and a connection area, the groove being located between the connection area and the first flange; a third providing device for providing a first current collector; a fourth providing device for providing an end cap; and a first assembling device for connecting the first current collector to the first tab; a second assembling device for placing the electrode assembly and the first current collector into the housing and making the first current collector located between the bottom wall and the electrode assembly; a third assembling device for connecting the first current collector to the connection area; and a fourth assembling device for covering the opening of the housing with the end cap.

[0044] In an embodiment of the present application, the third assembling device is used to weld the first current collector to the connection area, and the third assembling device includes a welding unit, the welding unit being used to enter the housing and pass through the winding center hole of the electrode assembly to weld the first current collector and the connection area.

[0045] In a sixth aspect, an embodiment of the present application provides an assembly method for a housing and an electrode terminal, which includes: providing a housing, the housing including a bottom wall and a side wall, the side wall surrounding the bottom wall, one end of the side wall being connected to the bottom wall, the other end of the side wall enclosing an opening opposite to the bottom wall, and the bottom wall being provided with an electrode lead-out hole; providing an electrode terminal, the electrode terminal including a terminal body and a first flange, the terminal body having a first end face, the first flange protruding from the first end face along the central axis direction of the terminal body, the first flange surrounding the first end face, and the first end face being provided with a groove and a connection area, the groove being located between the connection area and the first flange; passing the electrode terminal through the electrode lead-out hole such that the first flange is located inside the bottom wall, and bending the first flange so that the first flange protrudes radially from the outer peripheral surface of the terminal body along the electrode terminal to restrict the electrode terminal from moving outward of the bottom wall through the first flange.

[0046] In the above technical solution, the first flange initially protrudes from the first end face along the central axis direction of the terminal body, so that one end of the electrode terminal with the first flange can pass through the electrode lead-out hole and be located inside the housing. After bending, the first flange is turned outward, and the first flange protrudes radially from the outer peripheral surface of the terminal body, so that the electrode terminal cannot move to the outside of the housing, realizing the installation of the electrode terminal and the housing. At the same time, by providing a groove on the first end face of the terminal body, the groove being located between the connection area and the first flange, during the process of bending the first flange, the stress received by the first flange is released at the groove, so as not to transfer the stress to the connection area, ensuring the flatness of the connection area. Moreover, during the process of bending the first flange, the first flange is extruded and the material flows around. Since there is a groove between the first flange and the connection area, the extruded and flowing material is absorbed by the groove, preventing it from entering the connection area and ensuring that the connection area remains flat and unchanged in shape.

[0047] Seventh aspect, an assembly device for a housing and an electrode terminal provided by an embodiment of the present application includes: a fifth providing device for providing a housing, the housing including a bottom wall and a side wall, the side wall surrounding the bottom wall, one end of the side wall being connected to the bottom wall, the other end of the side wall enclosing an opening opposite to the bottom wall, and the bottom wall being provided with an electrode lead-out hole; a sixth providing device for providing an electrode terminal, the electrode terminal including a terminal body and a first flange, the terminal body having a first end face, the first flange protruding from the first end face along the central axis direction of the terminal body, the first flange being arranged around the first end face, and the first end face being provided with a groove and a connection area, the groove being located between the connection area and the first flange; a fifth assembling device for passing the electrode terminal through the electrode lead-out hole, making the first flange located inside the bottom wall, and bending the first flange so that the first flange protrudes from the outer peripheral surface of the terminal body along the radial direction of the electrode terminal, so as to limit the movement of the electrode terminal to the outside of the bottom wall through the first flange. Description of the Drawings

[0048] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.

[0049] Figure 1 Structural diagram of a vehicle provided by an embodiment of the present application;

[0050] Figure 2 Exploded view of a battery provided by an embodiment of the present application;

[0051] Figure 3 Stereogram of a battery cell provided by an embodiment of the present application;

[0052] Figure 4 Exploded view of a battery cell provided by an embodiment of the present application;

[0053] Figure 5 Cross-sectional view of a battery cell provided by an embodiment of the present application;

[0054] Figure 6 Schematic diagram of the electrical connection structure between an electrode terminal and a first tab provided by an embodiment of the present application;

[0055] Figure 7 Stereogram of an electrode terminal provided by an embodiment of the present application;

[0056] Figure 8A schematic plan view of one side of the electrode terminal facing the first current collector member provided by an embodiment of the present application;

[0057] Figure 9 A schematic plan view of one side of the electrode terminal facing the first current collector member provided by another embodiment of the present application;

[0058] Figure 10 A schematic plan view of one side of the electrode terminal facing the first current collector member provided by yet another embodiment of the present application;

[0059] Figure 11 A schematic plan view of one side of the electrode terminal facing the first current collector member provided by still another embodiment of the present application;

[0060] Figure 12 A perspective view of the first current collector member provided by an embodiment of the present application;

[0061] Figure 13 A sectional view of the first current collector member provided by an embodiment of the present application;

[0062] Figure 14 For Figure 5 An enlarged view of part A;

[0063] Figure 15 A schematic flow chart of the preparation method of the battery cell provided by an embodiment of the present application;

[0064] Figure 16 A schematic diagram of the welding process between the first current collector member and the connection area provided by an embodiment of the present application;

[0065] Figure 17 A schematic block diagram of the preparation device of the battery cell provided by an embodiment of the present application;

[0066] Figure 18 A schematic flow chart of the assembly method of the housing and the electrode terminal provided by an embodiment of the present application;

[0067] Figure 19 A schematic structural diagram of the initial state of the housing and the electrode terminal provided by an embodiment of the present application;

[0068] Figure 20 A schematic diagram of the assembly process of the housing and the electrode terminal provided by an embodiment of the present application;

[0069] Figure 21 A schematic structural diagram of the completed assembly of the housing and the electrode terminal provided by an embodiment of the present application;

[0070] Figure 22 A schematic block diagram of the assembly device of the housing and the electrode terminal provided by an embodiment of the present application.

[0071] Icons: 1000 - vehicle; 100 - battery; 101 - housing; 1011 - first housing part; 1012 - second housing part; 1 - battery cell; 11 - outer shell; 11a - wall part; 11b - electrode lead-out hole; 111 - housing body; 1111 - side wall; 1112 - bottom wall; 112 - end cap; 12 - electrode assembly; 121 - main body part; 122 - first tab; 123 - second tab; 124 - winding center hole; 13 - electrode terminal; 131 - terminal body; 1311 - first end face; 13111 - connection area; 13112 - groove; 13112a - inner groove wall; 13112b - outer groove wall; 132 - first flange; 133 - inclined surface; 134 - second flange; 1341 - annular protrusion; 14 - first current collector member; 141 - current collector body; 142 - protrusion; 1421 - peripheral wall; 1422 - end wall; 1423 - concave cavity; 15 - second current collector member; 151 - through hole; 16 - insulating member; 161 - first part; 162 - second part; 163 - third part; 200 - motor; 300 - controller; 400 - preparation device; 401 - first providing device; 402 - second providing device; 403 - third providing device; 404 - fourth providing device; 405 - first assembling device; 406 - second assembling device; 407 - third assembling device; 4071 - welding unit; 408 - fourth assembling device; 500 - assembling device; 501 - fifth providing device; 502 - sixth providing device; 503 - fifth assembling device; 5031 - upsetting mechanism; D1 - outer diameter of the groove; D2 - inner diameter of the groove; D3 - diameter of the protrusion; D4 - diameter of the concave cavity; D5 - diameter of the winding center hole; P - central axis direction of the terminal body; R - radial direction of the terminal body. Detailed implementation manners

[0072] For the purposes, technical solutions, and advantages of the embodiments of the present application to be clearer, the technical solutions in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope protected by the present application.

[0073] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used in the description of the application in this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the description and claims of this application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the description and claims of this application or the above drawings are used to distinguish different objects and not to describe a specific order or primary-secondary relationship.

[0074] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments.

[0075] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "joined", "attached" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0076] The term "and / or" in this application is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: the existence of A, the simultaneous existence of A and B, and the existence of B. In addition, the character " / " in this application generally represents an "or" relationship between the associated objects before and after.

[0077] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, in different embodiments, the detailed description of the same components is omitted. It should be understood that the thickness, length, width, etc. of various components shown in the drawings in the embodiments of this application, as well as the overall thickness, length, width, etc. of the integrated device are only for illustrative purposes and should not constitute any limitation to this application.

[0078] The term "a plurality of" as used in this application means two or more (including two).

[0079] In this application, the battery cell can include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, a magnesium-ion battery cell, etc., and the embodiments of this application do not limit this.

[0080] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack, etc. Generally, a battery includes a case for encapsulating one or more battery cells. The case can prevent liquids or other foreign objects from affecting the charging or discharging of the battery cells.

[0081] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode plate, a negative electrode plate, and a separator. The battery cell mainly operates by the movement of metal ions between the positive electrode plate and the negative electrode plate. The positive electrode plate includes a positive current collector and a positive active material layer, and the positive active material layer is coated on the surface of the positive current collector; the positive current collector includes a positive current collecting portion and a positive electrode tab, the positive current collecting portion is coated with the positive active material layer, and the positive electrode tab is not coated with the positive active material layer. Taking a lithium-ion battery as an example, the material of the positive current collector can be aluminum, and the positive active material layer includes a positive active material, and the positive active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate, etc. The negative electrode plate includes a negative current collector and a negative active material layer, and the negative active material layer is coated on the surface of the negative current collector; the negative current collector includes a negative current collecting portion and a negative electrode tab, the negative current collecting portion is coated with the negative active material layer, and the negative electrode tab is not coated with the negative active material layer. The material of the negative current collector can be copper, and the negative active material layer includes a negative active material, and the negative active material can be carbon or silicon, etc. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc.

[0082] The battery cell also includes a housing for accommodating the electrode assembly and electrode terminals. The electrode terminals are installed on the housing and are used to electrically connect to the electrode assembly to realize the charging and discharging of the electrode assembly.

[0083] The battery cell also includes a current collecting member, which is used to electrically connect the electrode tabs and the electrode terminals of the battery cell to convey electrical energy from the electrode assembly to the electrode terminals and then to the outside of the battery cell through the electrode terminals; multiple battery cells are electrically connected through a busbar component to realize the series connection, parallel connection, or hybrid connection of multiple battery cells.

[0084] The current collecting member is an important component for the battery cell to achieve stable current transmission. If the connection part between the current collecting member and the electrode tab or the electrode terminal is damaged or poorly connected, it will cause unstable overcurrent of the battery cell, and it is also easy to cause an increase in the internal resistance of the connection part and heat damage, affecting the service life of the battery. The inventor noticed that the end face of the end of the electrode terminal located inside the housing is used to connect to the current collecting member. Therefore, the flatness of the end face of the electrode terminal is an important factor to ensure the stable connection between the electrode terminal and the current collecting member, and the force on the outer periphery of the electrode terminal is likely to cause deformation of the end face of the electrode terminal.

[0085] In view of this, the embodiments of the present application provide a technical solution. The electrode terminal includes a terminal body and a first flange. The terminal body penetrates through the wall portion of the housing. The first flange protrudes radially from the outer peripheral surface of the terminal body. The first flange is located inside the wall portion (i.e., inside the housing). The first flange directly or indirectly abuts against the inner side of the wall portion to limit the outward movement of the electrode terminal towards the outer side of the wall portion. The terminal body has a first end face facing the current collector member. The first end face is provided with a groove and a connection area. The groove is located between the connection area and the first flange. The groove can release the stress received by the first flange, so as to prevent the stress received by the first flange from being transmitted to the connection area, ensure that the connection area is flat and does not deform, thereby ensuring reliable connection between the electrode terminal and the current collector member, avoiding connection failure between the electrode terminal and the first current collector member, preventing the internal circuit of the battery cell from being disconnected, and ensuring stable current passing between the electrode terminal and the first current collector member, so as to improve the current-carrying capacity and service life of the battery cell.

[0086] The technical solution described in the embodiments of the present application is applicable to batteries and electrical equipment using batteries.

[0087] The electrical equipment 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 electric vehicle, or an extended-range electric 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 grinding wheel, an electric wrench, an electric screwdriver, a hammer drill, an impact electric drill, a concrete vibrator, and a power planer, etc. The embodiments of the present application do not make special restrictions on the above electrical equipment.

[0088] For the convenience of description, the following embodiments take the electrical equipment as a vehicle as an example for illustration.

[0089] As Figure 1As shown, the figure illustrates a vehicle 1000 according to an embodiment of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle, an extended-range vehicle, etc. Inside the vehicle 1000, a battery 100, a controller 300, and a motor 200 can be provided. The controller 300 is used to control the power supply of the battery 100 to the motor 200. For example, the battery 100 can be provided at the bottom, the front end, or the rear end 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 and is used for the circuit system of the vehicle 1000, such as the working power consumption requirements for starting, navigation, and operation of the vehicle 1000. In another embodiment 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.

[0090] To meet different power usage requirements, such as Figure 2 As shown, the battery 100 can include a plurality of battery cells 1. Among them, the plurality of battery cells 1 can be connected in series, in parallel, or in a series-parallel combination. The series-parallel combination means a combination of series and parallel connections. The battery 100 can also be referred to as a battery 100 pack. Optionally, the plurality of battery cells 1 can first be connected in series, in parallel, or in a series-parallel combination to form a battery module, and then a plurality of battery modules are connected in series, in parallel, or in a series-parallel combination to form the battery 100. That is to say, the plurality of battery cells 1 can directly form the battery 100, or can first form a battery module, and then the battery module forms the battery 100.

[0091] The battery 100 can further include a box body 101 (or called a cover body). The inside of the box body 101 is a hollow structure, and the plurality of battery cells 1 are accommodated in the box body 101. The box body 101 can include two parts for accommodation (which can be referred to Figure 2), which are respectively referred to as the first box body part 1011 and the second box body part 1012 here, and the first box body part 1011 and the second box body part 1012 are buckled together. The shapes of the first box body part 1011 and the second box body part 1012 can be determined according to the shape of the combination of multiple battery cells 1, and the first box body part 1011 and the second box body part 1012 can both have an opening. For example, both the first box body part 1011 and the second box body part 1012 can be hollow cuboids and each has only one face as the opening face. The openings of the first box body part 1011 and the second box body part 1012 are arranged opposite to each other, and the first box body part 1011 and the second box body part 1012 are buckled together to form a box body 101 with a closed chamber. In the first box body part 1011 and the second box body part 1012, one can be a cuboid with an opening, and the other can be a cover plate structure to close the opening of the cuboid. Multiple battery cells 1 are placed in the box body 101 formed after the first box body part 1011 and the second box body part 1012 are buckled together after being connected in parallel or in series or in a mixed connection.

[0092] Optionally, the battery 100 may further include other structures. For example, the battery 100 may further include a busbar component (not shown in the figure), and the busbar component is used to realize the electrical connection between multiple battery cells 1, such as in parallel or in series or in a mixed connection. Specifically, the busbar component can realize the electrical connection between battery cells 1 by connecting the electrode terminals 13 of the battery cells 1. Further, the busbar component can be fixed to the electrode terminals 13 of the battery cells 1 by welding. The electrical energy of multiple battery cells 1 can be further led out through a conductive mechanism passing through the box body 101. Optionally, the conductive mechanism may also belong to the busbar component.

[0093] The following will be described in detail for any one of the battery cells 1, as Figure 3 、 Figure 4 、 Figure 5 and Figure 6 shown, the battery cell 1 includes an electrode assembly 12, a housing 11, an electrode terminal 13, and a first current collector member 14. As Figure 4 and Figure 5 shown, the housing 11 includes a wall portion 11a, and the wall portion 11a is provided with an electrode lead-out hole 11b. The electrode assembly 12 is arranged inside the housing 11, and a first tab 122 is formed at one end of the electrode assembly 12 facing the wall portion 11a. As Figure 6As shown, the electrode terminal 13 includes a terminal body 131 and a first flange 132. The terminal body 131 passes through the electrode lead-out hole 11b. The first flange 132 protrudes radially R from the outer peripheral surface of the terminal body 131. The first flange 132 is located inside the wall portion 11a to limit the movement of the electrode terminal 13 in the direction away from the electrode assembly 12. The first current collector member 14 is located between the wall portion 11a and the electrode assembly 12 and is used to connect the electrode terminal 13 and the first tab 122. Among them, the terminal body 131 has a first end face 1311 facing the first current collector member 14. The first end face 1311 is provided with a groove 13112 and a connection area 13111 for connecting with the first current collector member 14. The groove 13112 is located between the connection area 13111 and the first flange 132.

[0094] The electrode assembly 12 includes a first electrode plate, a second electrode plate, and a separator. The separator is used to separate the first electrode plate and the second electrode plate. The polarities of the first electrode plate and the second electrode plate are opposite. In other words, one of the first electrode plate and the second electrode plate is a positive electrode plate, and the other of the first electrode plate and the second electrode plate is a negative electrode plate. The first electrode plate, the second electrode plate, and the separator are prior arts. Although not shown in the accompanying drawings of the present application specification, those skilled in the art should understand their specific structures. From the external shape of the electrode assembly 12, the electrode assembly 12 includes a main body portion 121, a first tab 122, and a second tab 123. The first tab 122 and the second tab 123 protrude from the main body portion 121. The first tab 122 is the part of the first electrode plate where the active material layer is not coated, and the second tab 123 is the part of the second electrode plate where the active material layer is not coated. The first tab 122 and the second tab 123 can extend from the same side of the main body portion 121 or can extend from opposite sides respectively. Exemplarily, as Figure 4 and Figure 5 shown, the first tab 122 and the second tab 123 are respectively arranged at both ends of the main body portion 121, that is, the first tab 122 and the second tab 123 are respectively located at both ends of the electrode assembly 12.

[0095] The outer shell 11 has a hollow structure, and a space for accommodating the electrode assembly 12 is formed inside it. The shape of the outer shell 11 can be determined according to the specific shape of the electrode assembly 12. For example, if the electrode assembly 12 is a cylindrical structure, the outer shell 11 can be selected as a cylindrical shell; if the electrode assembly 12 is a cuboid structure, the outer shell 11 can be selected as a cuboid shell. Optionally, both the electrode assembly 12 and the outer shell 11 are cylindrical. The wall portion 11a is the end wall of one end of the outer shell 11. The wall portion 11a faces the first tab 122 of the electrode assembly 12, and the end of the outer shell 11 away from the wall portion 11a faces the second tab 123 of the electrode assembly 12.

[0096] The electrode lead-out hole 11b penetrates through the wall portion 11a to communicate the inside of the wall portion 11a with the outside of the wall portion 11a. The inside of the wall portion 11a is the interior of the housing 11, and the outside of the wall portion 11a is the exterior of the housing 11.

[0097] The electrode terminal 13 is installed in the electrode lead-out hole 11b to achieve the electrical connection between the first tab 122 of the electrode assembly 12 and the external busbar component.

[0098] Herein, the fact that the terminal body 131 passes through the electrode lead-out hole 11b means that one end of the terminal body 131 is located inside the housing 11 and the other end is located outside the housing 11, that is, both ends of the terminal body 131 are located on both sides of the wall portion 11a. One end of the terminal body 131 located inside the wall portion 11a is used to connect the first tab 122, and one end of the terminal body 131 located outside the wall portion 11a is used to connect the external busbar component. The shape of the terminal body 131 is not limited and can be a cylinder, a polygonal prism, or other special-shaped prisms. Optionally, the shape of the terminal body 131 is a cylinder.

[0099] The first end face 1311 is the end face of one end of the terminal body 131 located inside the wall portion 11a, and the connection area 13111 is the middle area of the first end face 1311. In the area between the first flange 132 and the connection area 13111, it is recessed downward along the central axis direction P of the terminal body from the first end face 1311 to form a groove 13112.

[0100] The central axis of the terminal body 131 is perpendicular to the first end face 1311. Figure 6 As shown in the figure, the central axis direction P of the terminal body is visible. The radial direction R of the terminal body refers to the direction perpendicular to the central axis direction P of the terminal body.

[0101] The first flange 132 is a protrusion provided on the outer peripheral surface of the terminal body 131, that is, the first flange 132 protrudes radially R relative to the terminal body from the outer peripheral surface of the terminal body 131. The first flange 132 is located at one end of the terminal body 131 inside the wall portion 11a, and the first flange 132 directly abuts or indirectly abuts against the wall portion 11a to prevent the terminal body 131 from moving outward to the wall portion 11a, so as to prevent the terminal body 131 from moving away from the electrode assembly 12 and detaching from the wall portion 11a. The terminal body 131 and the first flange 132 can be integrally formed, or can be two parts formed separately and connected by welding, bonding or other means. Optionally, the first flange 132 and the terminal body 131 are integrally formed. The first current collector member 14 is located between the first tab 122 and the wall portion 11a. One side of the first current collector member 14 facing the electrode assembly 12 is electrically connected to the first tab 122, and one side of the first current collector member 14 facing the wall portion 11a is electrically connected to the terminal body 131. Optionally, the first current collector member 14 has a disc-like structure. The disc-like structure presses against and is electrically connected to the first tab 122 of the electrode assembly 12, and the other side of the disc-like structure presses against and is electrically connected to the connection area 13111 on the first end surface 1311 of the terminal body 131. The electrical connection method can be contact conduction, bonding through a conductive adhesive, or welding.

[0102] When the connection area 13111 is uneven, the surface of the first current collector member 14 and the surface of the connection area 13111 cannot be in full contact, and there is a gap between the first current collector member 14 and the connection area 13111, resulting in poor contact, low bonding strength during bonding, and virtual soldering during welding, unstable electrical connection, small current-carrying area, and poor current-carrying capacity. In severe cases, the connection between the first current collector member 14 and the connection area 13111 may fail, and the internal circuit of the battery cell 1 may be disconnected. By providing a groove 13112 on the first end surface 1311 to separate the connection area 13111 and the first flange 132, the stress received by the first flange 132 is released at the groove 13112, preventing the stress from being transmitted to the connection area 13111, alleviating the problem of deformation of the connection area 13111 under stress, ensuring the flatness of the connection area 13111, and further alleviating the problem of unstable connection caused by the gap between the connection area 13111 and the first current collector member 14, thereby improving the current-carrying capacity and extending the service life.

[0103] According to some embodiments of the present application, as Figure 7 and Figure 8 shown, the groove 13112 is an annular groove provided around the outer periphery of the connection area 13111.

[0104] As Figure 7 and Figure 8As shown, the groove 13112 is a 360° annular structure. The groove 13112 includes an inner groove wall 13112a located in the inner circle and an outer groove wall 13112b located in the outer circle. The connection area 13111 is formed within the enclosed area of the inner groove wall 13112a. The shape of the annular groove can be a circular ring or a polygonal ring.

[0105] The stress received by the first flange 132 is transmitted to the outer groove wall 13112b of the groove 13112. The space between the outer groove wall 13112b and the inner groove wall 13112a can release the stress received by the first flange 132 to prevent the connection area 13111 connected to the inner groove wall 13112a from deforming. By setting the groove 13112 as an annular groove and using the enclosed area of the groove 13112 as the connection area 13111, the stress in any direction is restricted from being transmitted to the connection area 13111, further ensuring the flatness of the connection area 13111.

[0106] In some embodiments, the groove 13112 may not be a 360° enclosed annular groove. For example, as Figure 10 shown, an arc-shaped groove 13112 is provided on the first end face 1311. The groove 13112 extends along the circumferential direction of the terminal body 131. The radian of the groove 13112 is less than 360°. The first flange 132 protrudes radially from the outer peripheral surface of the terminal body 131 at the position corresponding to the groove 13112. Another example, as Figure 11 shown, a plurality of arc-shaped grooves 13112 ([[]] Figure 11 [[]] taking four as an example) are provided on the first end face 1311 at intervals along the circumferential direction of the terminal body 131. Each groove 13112 extends along the circumferential direction of the terminal body 131. The first flange 132 includes a plurality of them. The plurality of first flanges 132 correspond to the plurality of grooves 13112. The plurality of grooves 13112 respectively isolate the plurality of first flanges 132 and the connection area 13111. In some embodiments, the groove 13112 may also not have a radian and be a strip-shaped groove. As Figure 12 shown, the terminal body 131 is a polygonal column, and the groove 13112 extends along the circumferential direction of the terminal body 131 to form a strip-shaped groove.

[0107] According to some embodiments of the present application, as Figure 6 shown, the electrode assembly 12 is a wound structure, and the first current collector member 14 covers the winding center hole 124 of the electrode assembly 12.

[0108] ​​As previously described, the electrode assembly 12 includes a separator and first and second electrode sheets of opposite polarity. The separator is used to separate the first and second electrode sheets. The first and second electrode sheets, as well as the separator, are all strip-shaped structures. The first and second electrode sheets, as well as the separator, are wound together around a central axis to form a wound structure. The wound structure can be cylindrical, flat, or other shaped. During winding, the first and second electrode sheets, as well as the separator, are wound around a winding needle. After the winding needle is withdrawn, a winding center hole 124 is formed at the central axis of the electrode assembly 12. Optionally, the first electrode tab 122 is wound around the central axis of the electrode assembly 12 in multiple turns. In other words, the first electrode tab 122 includes multiple turns of the tab layer. After winding, the first electrode tab 122 is generally cylindrical, with a gap between adjacent turns of the tab layer. In embodiments of the present application, the first electrode tab 122 can be treated to reduce the gap between the tab layers, facilitating connection of the first electrode tab 122 to the first current collecting member 14. For example, in an embodiment of the present application, the first pole tab 122 may be flattened so that the end region of the first pole tab 122 away from the main body 121 is gathered and brought together; the flattening process forms a dense end surface at the end of the first pole tab 122 away from the main body 121, reducing the gap between the pole tab layers, and facilitating the connection of the first pole tab 122 to the first current collecting member 14. Alternatively, in an embodiment of the present application, a conductive material may be filled between two adjacent turns of the pole tab layers to reduce the gap between the pole tab layers. Optionally, the second pole tab 123 is wound around the central axis of the electrode assembly 12 into multiple turns, and the second pole tab 123 includes multiple turns of the pole tab layers. Exemplarily, the second pole tab 123 is also flattened to reduce the gap between the pole tab layers of the second pole tab 123.

[0109] The first current collecting member 14 is pressed against the flattened end surface of the first electrode tab 122 , with a portion of the first current collecting member 14 covering the first electrode tab 122 and another portion exposed to the winding center hole 124 . An external welding device emits a laser on the surface of the first current collecting member 14 facing away from the first electrode tab 122 , and the laser welds the portion of the first current collecting member 14 covering the first electrode tab 122 to the first electrode tab 122 .

[0110] The portion of the first current collecting member 14 exposed to the winding center hole 124 is pressed against the connection area 13111. A welding tool can be used to pass through the winding center hole 124 to weld the first current collecting member 14 to the connection area 13111, so that the weld mark is located inside the outer shell 11 to prevent the weld mark from being exposed to the outside and preventing the weld mark from being oxidized and rusted by the outside air, thereby improving the service life of the battery 100.

[0111] When the first current collector member 14 is electrically connected to the connection area 13111 by bonding with conductive adhesive, instead of indirectly applying pressure towards the wall portion 11a to the first current collector member 14 through the electrode assembly 12, a tool can be used to directly apply pressure to the first current collector member 14 through the winding center hole 124 to press the first current collector member 14 against the connection area 13111, so that the first current collector member 14 and the connection area 13111 are stably bonded. This can prevent the electrode assembly 12 from being deformed by force and causing the active material layer coated on the electrode sheet to fall off, and also prevent damage to the electrode assembly 12.

[0112] According to some embodiments of the present application, as Figure 6 and Figure 12 shown, the first current collector member 14 includes a current collector body 141 and a convex portion 142. The convex portion 142 protrudes from the current collector body 141 in the direction towards the electrode terminal 13. The convex portion 142 corresponds to the position of the winding center hole 124 of the electrode assembly 12 and is used to connect the connection area 13111, and the current collector body 141 is used to connect the first tab 122.

[0113] The current collector body 141 is the part of the first current collector member 14 that covers the first tab 122, and the current collector body 141 is welded to the first tab 122.

[0114] The convex portion 142 protrudes from the current collector body 141 in the direction towards the electrode terminal 13, so as to avoid interference between the structure other than the connection area 13111 between the current collector body 141 and the electrode terminal 13, which may cause the first current collector member 14 not to be in close contact with the connection area 13111. By providing the convex portion 142, it is ensured that the first current collector member 14 is in close contact with the connection area 13111, so as to avoid poor bonding or poor welding, achieve stable current conduction, and improve the current-carrying capacity and service life of the battery 100.

[0115] According to some embodiments of the present application, as Figure 13 and Figure 14 shown, the outer diameter D1 of the groove is greater than the diameter D3 of the convex portion.

[0116] As Figure 7 and Figure 8 shown, the groove 13112 is a ring, and the outer diameter D1 of the groove refers to the diameter of the outer groove wall 13112b of the groove 13112. As Figure 12 and Figure 13 shown, the convex portion 142 is cylindrical, and the diameter D3 of the convex portion refers to the diameter of the end face of the cylinder. Combining Figure 8 and Figure 14As shown, the area of the region enclosed by the outer groove wall 13112b of the groove 13112 is greater than the area of the surface of the convex portion 142 facing the connection region 13111. Along the central axis direction P of the terminal body, the projection of the convex portion 142 on the first end face 1311 falls within the region enclosed by the outer groove wall 13112b. Optionally, the central axes of the groove 13112 and the convex portion 142 are on the same straight line. Optionally, the central axes of both the groove 13112 and the convex portion 142 are on the central axis of the terminal body 131. Optionally, the convex portion 142 can also be a polygonal column, and the diameter of the outer groove wall 13112b of the groove 13112 is greater than the diameter of the circumscribed circle of the end face of the polygonal column.

[0117] When the groove 13112 is a polygonal ring, the convex portion 142 can be a cylinder or correspondingly set as a polygonal column: when the convex portion 142 is a cylinder, the diameter of the inscribed circle of the outer groove wall 13112b of the groove 13112 is greater than the diameter of the end face of the cylinder; when the convex portion 142 is a polygonal column, the diagonal length of the region enclosed by the outer groove wall 13112b of the groove 13112 is greater than the diagonal length of the end face of the polygonal column. Thus, the projection of the convex portion 142 on the first end face 1311 falls within the region enclosed by the outer groove wall 13112b.

[0118] Through the above settings, the convex portion 142 does not extend radially beyond the outer groove wall 13112b of the terminal body, so as to avoid interference between the convex portion 142 and structures other than the connection region 13111, and ensure that there is no gap and a tight connection between the convex portion 142 and the connection region 13111.

[0119] According to some embodiments of the present application, as Figure 14 shown, the inner diameter D2 of the groove is smaller than the diameter D3 of the convex portion.

[0120] Combined with Figure 8 、 Figure 13 and Figure 14 shown, the groove 13112 is a circular ring, and the inner diameter D2 of the groove refers to the diameter of the inner groove wall 13112a of the groove 13112. The region enclosed by the inner groove wall 13112a of the groove 13112 is the connection region 13111, and the shape of the connection region 13111 is circular. The inner diameter D2 of the groove can also be understood as the diameter of the connection region 13111. The convex portion 142 is a cylinder, and the diameter D3 of the convex portion refers to the diameter of the cylinder. The diameter of the connection region 13111 is smaller than the diameter D3 of the cylindrical convex portion, so that the area of the surface of the convex portion 142 facing the connection region 13111 is greater than the area of the region enclosed by the inner groove wall 13112a of the groove 13112, that is, the surface of the convex portion 142 facing the connection region 13111 completely covers the connection region 13111. Optionally, the convex portion 142 can also be set as a polygonal column, and the diameter of the inner groove wall 13112a of the groove 13112 is smaller than the diameter of the inscribed circle of the end face of the polygonal column.

[0121] When the groove 13112 is a polygonal ring, the shape of the connection area 13111 is polygonal, and the convex part 142 can be cylindrical or correspondingly set as a polygonal column: when the convex part 142 is cylindrical, the diameter of the circumscribed circle of the connection area 13111 is smaller than the diameter of the end face of the cylinder. When the convex part 142 is a polygonal column, the diagonal length of the connection area 13111 is smaller than the diagonal length of the end face of the polygonal column.

[0122] With the above settings, the surface of the convex part 142 facing the connection area 13111 completely covers the connection area 13111, maximizing the utilization of the connection area 13111 and maximizing the guaranteed current-carrying area.

[0123] According to some embodiments of the present application, as Figure 13 shown, the convex part 142 includes an end wall 1422 and a peripheral wall 1421. The peripheral wall 1421 surrounds the end wall 1422. The peripheral wall 1421 is connected to the current collector body 141, the end wall 1422 is connected to the connection area 13111, and the peripheral wall 1421 and the end wall 1422 together enclose a concave cavity 1423.

[0124] One end of the peripheral wall 1421 is connected to the current collector body 141. The other end of the peripheral wall 1421 extends toward the electrode terminal 13 and is connected to the end wall 1422. The end wall 1422 is offset from the current collector body 141. The end wall 1422 is closer to the wall portion 11a relative to the current collector body 141. A concave cavity 1423 is formed on the side of the first current collector member 14 facing away from the wall portion 11a. In other words, the side of the convex part 142 facing away from the wall portion 11a is provided as the concave cavity 1423.

[0125] The concave cavity 1423 marks the position of the convex part 142 on the side of the first current collector member 14 facing away from the wall portion 11a, so as to weld the end wall 1422 and the connection area 13111 from the inside of the wall portion 11a.

[0126] During welding, the concave cavity 1423 is also used to position the welding head to prevent the welding head from deviating and ensure a stable connection between the convex part 142 and the connection area 13111. Compared with the case where no concave cavity 1423 is provided on the back surface of the convex part 142, by providing the concave cavity 1423, the thickness of the part of the convex part 142 for connecting the connection area 13111 (i.e., the end wall 1422) is thinned, facilitating penetration welding.

[0127] According to some embodiments of the present application, as Figure 14 shown, the diameter D4 of the concave cavity is greater than the diameter D5 of the winding center hole.

[0128] When the back surface of the convex portion 142 is the concave cavity 1423, the projection of the peripheral wall 1421 on the end surface of the electrode assembly 12 is annular, and the diameter D4 of the concave cavity refers to the inner diameter of the projection of the peripheral wall 1421. The concave cavity 1423 completely covers one end of the winding center hole 124, and the welding head will not interfere with the current collecting body 141 after passing through the winding center hole 124, and the welding head can smoothly enter the concave cavity 1423 to weld the end wall 1422 and the connection area 13111.

[0129] When the diameter of the concave cavity 1423 is fixed, by reducing the diameter D5 of the winding center hole of the electrode assembly 12 to make the diameter D5 of the winding center hole smaller than the diameter D4 of the concave cavity, the space occupancy ratio of the electrode assembly 12 is increased, and the energy density of the battery cell 1 is improved.

[0130] According to some embodiments of the present application, as Figure 14 shown, a slope 133 is formed on the side of the electrode terminal 13 facing the first current collecting member 14. The slope 133 is inclined with respect to a plane perpendicular to the central axis direction of the electrode terminal 13 and extends from the outer groove wall 13112b of the groove 13112 towards the direction close to the electrode assembly 12.

[0131] The slope 133 is located on the side of the electrode terminal 13 facing the first current collecting member 14. The slope 133 starts from the outer groove wall 13112b and extends radially away from the central axis of the electrode terminal 13 and gradually approaches the electrode assembly 12. The slope 133 is located on the periphery of the outer groove wall 13112b of the groove 13112. In other words, the groove 13112 is located between the connection area 13111 and the slope 133.

[0132] By providing the slope 133 on the periphery of the groove 13112 to avoid the first current collecting member 14, when the first current collecting member 14 moves towards the first end surface 1311, the slope 133 guides the first current collecting member 14 to move towards the connection area 13111 to accurately position the first current collecting member 14 and ensure that the first current collecting member 14 is connected to the connection area 13111.

[0133] According to some embodiments of the present application, as Figure 7 and Figure 14 shown, the electrode terminal 13 further includes a second flange 134. The second flange 134 protrudes radially R from the outer peripheral surface of the terminal body 131. The second flange 134 is located outside the wall portion 11a to limit the movement of the electrode terminal 13 in the direction towards the electrode assembly 12.

[0134] One end of the terminal body 131 extending outside the housing 11 is provided with a second flange 134. The second flange 134 is a protrusion provided on the outer peripheral surface of the terminal body 131, that is, the second flange 134 protrudes radially R relative to the terminal body from the outer peripheral surface of the terminal body 131. The second flange 134 directly abuts or indirectly abuts against the outer side of the wall portion 11a to prevent the terminal body 131 from moving inwardly towards the wall portion 11a. The terminal body 131 and the second flange 134 may be integrally formed or may be two parts formed separately and connected by means such as welding or bonding. Optionally, the second flange 134 is integrally formed with the terminal body 131.

[0135] By providing the second flange 134, under the combined action of the first flange 132 and the second flange 134, the movement of the electrode terminal 13 along the central axis of the terminal body 131 is restricted, and the electrode terminal 13 is positioned along the central axis direction P of the terminal body, so as to prevent the electrode terminal 13 from shaking and further ensure the stable connection between the electrode terminal 13 and the first current collecting member 14.

[0136] According to some embodiments of the present application, as Figure 14 shown, the battery cell 1 further includes an insulating member 16. The insulating member 16 is disposed between the electrode terminal 13 and the wall portion 11a to insulate and isolate the electrode terminal 13 and the wall portion 11a.

[0137] The insulating member 16 includes a first portion 161, a second portion 162, and a third portion 163 connected in sequence. The first portion 161 is located between the first flange 132 and the inner surface of the wall portion 11a, and the first flange 132 indirectly abuts against the wall portion 11a through the first portion 161. The second portion 162 surrounds the outer periphery of the terminal body 131, that is, the second portion 162 is located between the terminal body 131 and the inner wall of the electrode lead-out hole 11b. The third portion 163 is located between the second flange 134 and the inner surface of the wall portion 11a, and the second flange 134 indirectly abuts against the wall portion 11a through the third portion 163.

[0138] The electrode terminal 13 and the wall portion 11a are isolated by the insulating member 16 to prevent the wall portion 11a from being electrified and reduce the risk of short circuit. The insulating member 16 also fills the gap between the electrode terminal 13 and the wall portion 11a to alleviate the problem of liquid leakage from the gap between the electrode terminal 13 and the wall portion 11a.

[0139] According to some embodiments of the present application, an annular protrusion 1341 is formed on the side of the second flange 134 facing the wall portion 11a. The annular protrusion 1341 is arranged around the central axis of the electrode terminal 13, and the annular protrusion 1341 is configured to squeeze the portion of the insulating member 16 located between the second flange 134 and the wall portion 11a.

[0140] In other words, at the annular protrusion 1341, the distance between the second flange 134 and the outer surface of the wall portion 11a is reduced to further press the third portion 163 of the pressure insulating member 16 toward the outer surface of the wall portion 11a, so that an annular sealing area is formed between the second flange 134 and the wall portion 11a to further alleviate the problem of liquid leakage from the gap between the electrode terminal 13 and the wall portion 11a.

[0141] According to some embodiments of the present application, as Figure 7 shown, along the thickness direction of the wall portion 11a, the projection of the first flange 132 on the second flange 134 covers the annular protrusion 1341.

[0142] The distance from the edge of the first flange 132 to the central axis of the terminal body 131 is greater than the distance from the annular protrusion 1341 to the central axis of the terminal body 131. The annular protrusion 1341 presses the wall portion 11a through the insulating member 16 on the outer side of the wall portion 11a, and the first flange 132 supports the portion of the wall portion 11a that is pressed by the annular protrusion 1341 on the inner side to prevent the wall portion 11a from being deformed under pressure. With the cooperation of the wall portion 11a and the annular protrusion 1341, the insulating member 16 is ensured to be pressed tightly, the gap between the electrode terminal 13 and the wall portion 11a is eliminated, and the sealing effect is improved.

[0143] According to some embodiments of the present application, as Figure 5 and Figure 6 shown, the housing 11 includes a housing body 111 and an end cover 112. The housing body 111 includes a side wall 1111 and a bottom wall 1112. The side wall 1111 surrounds the bottom wall 1112. One end of the side wall 1111 is connected to the bottom wall 1112, and the other end of the side wall 1111 forms an opening opposite to the bottom wall 1112. The end cover 112 covers the opening, and the wall portion 11a is the bottom wall 1112 or the end cover 112.

[0144] An embodiment in which the wall portion 11a is the bottom wall 1112 is shown in the accompanying drawings of the specification of the present application. In other embodiments, the wall portion 11a may also be the end cover 112. The end cover 112 is provided with an electrode lead-out hole 11b, and the electrode terminal 13 passes through the electrode lead-out hole 11b on the end cover 112. That is, one of the bottom wall 1112 and the end cover 112 is provided with the electrode terminal 13.

[0145] According to some embodiments of the present application, as Figure 6 and Figure 7 shown, the electrode terminal 13 is insulated from the wall portion 11a. A second tab 123 is formed at one end of the electrode assembly 12 away from the wall portion 11a, and the second tab 123 has a polarity opposite to that of the first tab 122; the battery cell 1 further includes a second current collecting member 15, and the second current collecting member 15 is used for electrically connecting the second tab 123 and the wall portion 11a.

[0146] The wall portion 11a is the bottom wall 1112. The electrode terminal 13 is insulatingly disposed on the bottom wall 1112 and is electrically connected to the first tab 122 of the electrode assembly 12 through the first current collecting member 14. The end cap 112 is located at one end of the side wall 1111 away from the bottom wall 1112. The end cap 112 is connected to the side wall 1111 to close the opening. The second current collecting member 15 is located between the electrode assembly 12 and the end cap 112.

[0147] The second current collecting member 15 is used for electrically connecting the second tab 123 and the wall portion 11a, which means that the second current collecting member 15 is electrically connected to the second tab 123 and at the same time the second current collecting member 15 is electrically connected to the wall portion 11a, so that the second tab 123 and the wall portion 11a carry the same-sex charges.

[0148] Optionally, the second current collecting member 15 abuts against the flattened end face of the second tab 123, and an external welding device emits laser on the surface of the second current collecting member 15 facing away from the second tab 123, and the laser welds the second current collecting member 15 and the second tab 123.

[0149] Optionally, the second current collecting member 15 is directly electrically connected to the housing 111 to lead the electric energy to the wall portion 11a.

[0150] Optionally, the second current collecting member 15 can also be indirectly electrically connected to the housing 111 through the end cap 112. As Figure 5 shown, the second current collecting member 15 is electrically connected to the end cap 112, and the end cap 112 is electrically connected to the side wall 1111. For example, the second current collecting member 15 is welded to the middle of the end cap 112, and the outer periphery of the end cap 112 is welded to the side wall 1111. Another example is that an electrode terminal 13 is provided on the end cap 112, the second current collecting member 15 is welded to the electrode terminal 13, and the outer periphery of the end cap 112 is welded to the side wall 1111.

[0151] Through the above settings, the polarities of the wall portion 11a and the electrode terminal 13 are opposite, and the wall portion 11a and the electrode terminal 13 can be used as the positive output terminal and the negative output terminal of the battery cell 1 respectively, so that the busbar component can connect the positive output terminal and the negative output terminal at the same end of the battery cell 1, which is convenient for assembly. Optionally, the pressure relief mechanism can be provided at one end away from the wall portion 11a, and the pressure relief mechanism is far from the busbar component, so as to prevent the pressure relief mechanism from impacting the busbar component when discharging, so as to prevent the busbar component from being damaged.

[0152] In a second aspect, an embodiment of the present application provides a battery 100, as Figure 2 and Figure 3 shown, the battery 100 includes the battery cell 1 described above.

[0153] In a third aspect, an embodiment of the present application provides an electrical device, as Figure 1 shown, the electrical device can be selected as a vehicle, and the vehicle includes the battery 100 described above.

[0154] In a fourth aspect, an embodiment of the present application provides a method for manufacturing a battery cell 1, as Figure 5 , Figure 6 and Figure 15 shown, the manufacturing method includes:

[0155] S101. Provide an electrode assembly 12, and a first tab 122 is formed at one end of the electrode assembly 12.

[0156] S102. Provide a housing 111 and an electrode terminal 13. The housing 111 includes a bottom wall 1112 and a side wall 1111. The side wall 1111 surrounds the bottom wall 1112. One end of the side wall 1111 is connected to the bottom wall 1112, and the other end of the side wall 1111 forms an opening opposite to the bottom wall 1112. The bottom wall 1112 is provided with an electrode lead-out hole 11b. The electrode terminal 13 includes a terminal body 131 and a first flange 132. The terminal body 131 passes through the electrode lead-out hole 11b. The first flange 132 protrudes radially R of the terminal body from the outer peripheral surface of the terminal body 131. The first flange 132 is located inside the bottom wall 1112 to limit the movement of the electrode terminal 13 in the direction away from the electrode assembly 12. The terminal body 131 has a first end face 1311 facing the inside of the housing 111. The first end face 1311 is provided with a groove 13112 and a connection area 13111 for connecting to the first current collector member 14. The groove 13112 is located between the connection area 13111 and the first flange 132.

[0157] S103. Provide a first current collector member 14.

[0158] S104. Connect the first current collector member 14 to the first tab 122.

[0159] S105. Place the electrode assembly 12 and the first current collector member 14 into the housing 111, and make the first current collector member 14 located between the bottom wall 1112 and the electrode assembly 12.

[0160] S106. Connect the first current collector member 14 to the connection area 13111.

[0161] S107. Provide an end cap 112 and cover the opening of the housing 111 with the end cap 112.

[0162] It should be noted that for the related structure of the battery cell 1 manufactured by the above method for manufacturing the battery cell 1, reference can be made to the battery cell 1 provided in the above embodiments.

[0163] When assembling the battery cell 1 according to the manufacturing method of the battery cell 1 described above, it is not necessary to perform the steps in sequence as described above. That is to say, the steps can be executed in the order mentioned in the embodiments, or in an order different from that mentioned in the embodiments, or several steps can be executed simultaneously. For example, the execution of steps S101 and S102 is not in a particular order and can also be carried out simultaneously.

[0164] According to some embodiments of the present application, the step of connecting the first current collector member 14 to the first tab 122 is completed before the step of placing the electrode assembly 12 into the housing 111.

[0165] That is, step S104 is completed before step S105, so that after the first current collector member 14 and the electrode assembly 12 are connected as a whole, the electrode assembly 12 and the first current collector member 14 are placed into the housing 111 together, ensuring the stable connection between the first current collector member 14 and the first tab 122 and improving the overcurrent capacity.

[0166] According to some embodiments of the present application, step S106 of connecting the first current collector member 14 to the connection area 13111 includes: as Figure 16 shown, the welding unit 4071 enters the housing 111 through the opening and passes through the winding center hole 124 of the electrode assembly 12 to weld the first current collector member 14 and the connection area 13111.

[0167] In the above technical solution, the welding mark between the first current collector member 14 and the electrode terminal 13 is located inside the battery cell 1, and the welding mark does not contact the external air, is not easily oxidized and rusted, and improves the service life of the battery 100.

[0168] In a fifth aspect, an embodiment of the present application provides a preparation device 400 for a battery cell 1, as Figure 17 shown, which includes:

[0169] A first providing device 401 for providing an electrode assembly 12, with a first tab 122 formed at one end of the electrode assembly 12;

[0170] A second providing device 402 for providing a housing 111 and an electrode terminal 13. The housing 111 includes a bottom wall 1112 and a side wall 1111. The side wall 1111 surrounds the bottom wall 1112. One end of the side wall 1111 is connected to the bottom wall 1112, and the other end of the side wall 1111 encloses an opening opposite to the bottom wall 1112. The bottom wall 1112 is provided with an electrode lead-out hole 11b. The electrode terminal 13 includes a terminal body 131 and a first flange 132. The terminal body 131 passes through the electrode lead-out hole 11b. The first flange 132 protrudes radially R of the terminal body from the outer peripheral surface of the terminal body 131. The first flange 132 is located inside the bottom wall 1112 to limit the movement of the electrode terminal 13 in the direction away from the electrode assembly 12. The terminal body 131 has a first end face 1311 facing the inside of the housing 111. The first end face 1311 is provided with a groove 13112 and a connection area 13111 for connecting to the first current collector member 14. The groove 13112 is located between the connection area 13111 and the first flange 132;

[0171] A third providing device 403 for providing a first current collector member 14;

[0172] A fourth providing device 404 for providing an end cap 112;

[0173] A first assembling device 405 for connecting the first current collector member 14 to the first tab 122;

[0174] A second assembling device 406 for placing the electrode assembly 12 and the first current collector member 14 into the housing 111 and making the first current collector member 14 located between the wall portion 11a and the electrode assembly 12;

[0175] A third assembling device 407 for connecting the first current collector member 14 to the connection area 13111;

[0176] A fourth assembling device 408 for covering the end cap 112 over the opening of the housing 111.

[0177] The first providing device 401, the second providing device 402, the third providing device 403, the fourth providing device 404, the first assembling device 405, the second assembling device 406, the third assembling device 407 and the fourth assembling device 408 can be arranged on the same production line. The first providing device 401, the second providing device 402, the third providing device 403, the fourth providing device 404 can be conveying devices on the production line. The first assembling device 405, the second assembling device 406, the third assembling device 407 and the fourth assembling device 408 assemble the components conveyed to form a battery cell 1.

[0178] According to some embodiments of the present application, the third assembling device 407 is used to weld the first current collector member 14 to the connection area 13111. The third assembling device 407 includes a welding unit 4071. The welding unit 4071 is configured to enter the housing 111 and pass through the winding central hole 124 of the electrode assembly 12 to weld the first current collector member 14 and the connection area 13111.

[0179] Optionally, the welding unit 4071 is an ultrasonic welding head. The ultrasonic welding head passes through the winding central hole 124 of the electrode assembly 12 and acts on the first current collector member 14 to weld the first current collector member 14 to the connection area 13111.

[0180] For the related structure of the battery cell 1 manufactured by the above preparation device 400, reference can be made to the battery cell 1 provided in the above embodiments.

[0181] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other.

[0182] In a sixth aspect, an embodiment of the present application provides an assembling method for a housing 111 and an electrode terminal 13. As Figure 18 shown, the assembling method includes:

[0183] S201, as Figure 19 shown, provide a housing 111. The housing 111 includes a bottom wall 1112 and a side wall 1111. The side wall 1111 surrounds the bottom wall 1112. One end of the side wall 1111 is connected to the bottom wall 1112, and the other end of the side wall 1111 forms an opening opposite to the bottom wall 1112. The bottom wall 1112 is provided with an electrode lead-out hole 11b;

[0184] S202, as Figure 19 shown, provide an electrode terminal 13. The electrode terminal 13 includes a terminal body 131 and a first flange 132. The terminal body 131 has a first end face 1311. The first flange 132 protrudes from the first end face 1311 along the central axis direction P of the terminal body. The first flange 132 is arranged around the first end face 1311. The first end face 1311 is provided with a groove 13112 and a connection area 13111. The groove 13112 is located between the connection area 13111 and the first flange 132;

[0185] S203, as Figure 20 shown, insert the electrode terminal 13 through the electrode lead-out hole 11b so that the first flange 132 is located inside the bottom wall 1112. As Figure 21 shown, bend the first flange 132 so that the first flange 132 protrudes radially from the outer peripheral surface of the terminal body 131 along the electrode terminal 13 to limit the movement of the electrode terminal 13 outward from the bottom wall 1112 through the first flange 132.

[0186] As Figure 20 shown, before assembly, the first flange 132 protrudes from the first end face 1311 along the central axis direction P of the terminal body, so that one end of the electrode terminal 13 with the first flange 132 can pass through the electrode lead-out hole 11b and be located inside the bottom wall 1112.

[0187] As Figure 21 shown, during assembly, the first flange 132 is folded outward, so that the first flange 132 protrudes from the outer peripheral surface of the terminal body 131 along the radial direction R of the terminal body, so as to limit the movement of the electrode terminal 13 to the outside of the bottom wall 1112 through the first flange 132.

[0188] The installation of the electrode terminal 13 and the housing 111 is realized by this assembly method, and the space near the connection area 13111 is also increased to facilitate the connection of the first current collector member 14. Since the groove 13112 is provided on the first end face 1311 of the terminal body 131, during the process of bending the first flange 132, the first flange 132 releases stress at the groove 13112, so as not to transfer the stress to the connection area 13111 and ensure the flatness of the connection area 13111. Moreover, during the process of bending the first flange 132, the first flange 132 is extruded and the material flows around. Since the groove 13112 is provided between the first flange 132 and the connection area 13111, the extruded and flowing material is absorbed by the groove 13112, preventing the material from entering the connection area 13111 and ensuring the flatness and non-deformation of the connection area 13111.

[0189] Specifically, in step S203, the first flange 132 is bent by pressing the first flange 132 along the central axis direction P of the terminal body, so that the electrode terminal 13 is riveted on the bottom wall 1112.

[0190] In a seventh aspect, an assembly device 500 for a housing 111 and an electrode terminal 13 is provided in an embodiment of the present application. With reference to Figures 19 - 22 shown, the assembly device 500 includes:

[0191] A fifth providing device 501 for providing the housing 111. The housing 111 includes a bottom wall 1112 and a side wall 1111. The side wall 1111 surrounds the bottom wall 1112. One end of the side wall 1111 is connected to the bottom wall 1112, and the other end of the side wall 1111 encloses an opening opposite to the bottom wall 1112. The bottom wall 1112 is provided with an electrode lead-out hole 11b;

[0192] The sixth providing device 502 is configured to provide an electrode terminal 13. The electrode terminal 13 includes a terminal body 131 and a first flange 132. The terminal body 131 has a first end face 1311. The first flange 132 protrudes from the first end face 1311 along the central axis direction P of the terminal body. The first flange 132 is disposed around the first end face 1311. The first end face 1311 is provided with a groove 13112 and a connection area 13111. The groove 13112 is located between the connection area 13111 and the first flange 132.

[0193] The fifth assembling device 503 is configured to pass the electrode terminal 13 through the electrode lead-out hole 11b, such that the first flange 132 is located inside the wall portion 11a, and bend the first flange 132 so that the first flange 132 protrudes from the outer peripheral surface of the terminal body 131 along the radial direction of the electrode terminal 13, thereby restricting the movement of the electrode terminal 13 outward of the wall portion 11a by the first flange 132.

[0194] Specifically, the fifth assembling device 503 includes a swaging mechanism 5031. The swaging mechanism 5031 is configured to enter the interior of the housing 111 from the opening of the housing 111 and swage the first flange 132 along the central axis direction P of the terminal body, so as to bend the first flange 132, thereby riveting the electrode terminal 13 to the bottom wall 1112.

[0195] According to some embodiments of the present application, referring to Figures 5 - 6 and Figure 14 , an embodiment of the present application provides a battery cell 1. The battery cell 1 includes a housing 11, an electrode terminal 13, an electrode assembly 12, a first current collector member 14, and a second current collector member 15.

[0196] The housing 11 includes a housing body 111 and an end cover 112. The housing body 111 includes a bottom wall and a side wall. The side wall 1111 surrounds the bottom wall. One end of the side wall 1111 is connected to the bottom wall 1112, and the other end of the side wall 1111 forms an opening opposite to the bottom wall 1112. The end cover 112 covers the opening. The bottom wall 1112 is provided with an electrode lead-out hole 11b for installing the electrode terminal 13. The electrode terminal 13 includes a terminal body 131, a first flange 132 and a second flange 134. The first flange 132 and the second flange 134 respectively protrude radially from the outer peripheral surface of the terminal body 131. The electrode terminal 13 is inserted through the electrode lead-out hole 11b. The first flange 132 is located inside the bottom wall 1112, and the first flange 132 is used to limit the movement of the terminal body 131 to the outside of the bottom wall 1112. The second flange 134 is located outside the bottom wall 1112, and the second flange 134 is used to limit the movement of the terminal body 131 to the inside of the bottom wall 1112. Among them, one end face of the terminal body 131 facing the electrode assembly 12 is the first end face 1311. A groove 13112 and a connection area 13111 are formed on the first end face 1311. The groove 13112 is an annular groove provided between the connection area 13111 and the first flange 132. The groove 13112 is used to allow the first flange 132 to release stress and deform, so as to limit the stress received by the first flange 13 to be transmitted to the connection area 13111 and ensure the flatness of the connection area 13111. An insulating member 16 is provided between the electrode terminal 13 and the bottom wall 1112. The insulating member 16 is used for insulating and isolating the electrode terminal 13 and the bottom wall 1112. An annular protrusion 1341 is formed on one side of the second flange 134 facing the bottom wall 1112. The annular protrusion 1341 extrudes the insulating member 16 outside the bottom wall 1112 to form an annular sealing area to seal the housing 11. The projection of the first flange 132 on the second flange 134 covers the annular protrusion 1341. The first flange 132 supports the bottom wall 1112 inside the bottom wall 1112 to prevent the bottom wall 1112 from being deformed by pressure and ensure the sealing effect.

[0197] The first current collector member 14, the second current collector member 15, and the electrode assembly 12 are located within the housing 11. The electrode assembly 12 has a wound structure. At one end of the electrode assembly 12 facing the bottom wall 1112, a first tab 122 is provided, and at one end of the electrode assembly 12 facing the end cap 112, a second tab 123 is provided. The first current collector member 14 is used to connect the first tab 122 of the electrode assembly 12, and the second current collector member 15 is used to connect the second tab 123 of the electrode assembly 12. Among them, the first current collector member 14 includes a current collector body 141 and a convex portion 142. The current collector body 141 is connected to the first tab 122. The convex portion 142 includes an end wall 1422 and a peripheral wall 1421. The peripheral wall 1421 surrounds the end wall 1422, and the peripheral wall 1421 and the end wall 1422 together define a cavity 1423. The peripheral wall 1421 is connected to the current collector body 141 so that the end wall 1422 protrudes in the direction towards the electrode terminal 13 relative to the current collector body 141, and the end wall 1422 is connected to the connection area 13111. The convex portion 142 and the groove 13112 satisfy: the inner diameter D2 of the groove < the diameter D3 of the convex portion < the outer diameter D1 of the groove. At the same time, the diameter D4 of the cavity > the diameter D5 of the winding center hole of the electrode assembly 12. The second current collector member 15 is connected to the second tab 123. The second current collector member 15 is provided with a through hole 151 corresponding to the winding center hole 124 of the electrode assembly 12. The side of the second current collector member 15 facing away from the electrode assembly 12 is connected to the end cap 112, so that the side wall 1111 and the bottom wall 1112 are charged.

[0198] With the above arrangement, the polarities of the electrode terminal 13 and the bottom wall 1112 are opposite, and the electrode terminal 13 and the bottom wall 1112 can serve as the positive output electrode and the negative output electrode of the battery cell 1 respectively, so as to facilitate connecting the bus bar components at the same end of the battery cell 1.

[0199] The embodiment of the present application also provides a preparation method for the above battery cell 1. Refer to Figure 5 、 Figure 6 and Figure 15 , the preparation method of the battery cell 1 includes: providing the electrode assembly 12, providing the assembled housing 111 and the electrode terminal 13 (refer to Figure 21) Provide a first current collector member 14, a second current collector member 15, and an end cap 112; connect the first current collector member 14 to the first tab 122, connect the second current collector member 15 to the second tab 123, and then integrally place the electrode assembly 12, the first current collector member 14, and the second current collector member 15 into the housing 11, with the first current collector member 14 located between the bottom wall 1112 and the electrode assembly 12; insert the welding unit (such as an ultrasonic welding head) into the housing 111 through the opening, sequentially pass through the through hole 151 on the second current collector member 15, the winding center hole 124 of the electrode assembly 12, and enter the cavity 1423, and act on the end wall 1422 to weld the end wall 1422 to the connection area 13111, realizing the electrical connection between the first current collector member 14 and the electrode terminal 13, and covering the opening with the end cap 112.

[0200] Among them, for the assembly method of the housing 111 and the electrode terminal 13, refer to Figures 18 - 21 , including: providing the housing 111, as Figure 19 shown, the housing 111 includes a bottom wall 1112 and a side wall 1111, the side wall 1111 surrounds the bottom wall 1112, one end of the side wall 1111 is connected to the bottom wall 1112, the other end of the side wall 1111 encloses an opening opposite to the bottom wall 1112, and the bottom wall 1112 is provided with an electrode lead-out hole 11b; providing the electrode terminal 13, as Figure 19 shown, the electrode terminal 13 includes a terminal body 131 and a first flange 132, the terminal body 131 has a first end face 1311, the first flange 132 protrudes from the first end face 1311 along the central axis direction P of the terminal body, the first flange 132 is arranged around the first end face 1311, the first end face 1311 is provided with a groove 13112 and a connection area 13111, and the groove 13112 is located between the connection area 13111 and the first flange 132; as Figure 20 shown, insert the electrode terminal 13 through the electrode lead-out hole 11b, with the first flange 132 located inside the wall portion 11a, as Figure 21 shown, bend the first flange 132 so that the first flange 132 protrudes radially from the outer peripheral surface of the terminal body 131 along the electrode terminal 13 to restrict the outward movement of the electrode terminal 13 relative to the wall portion 11a through the first flange 132.

[0201] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various modifications and changes 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: A housing including a wall portion provided with an electrode lead-out hole; An electrode assembly disposed inside the housing, with a first tab formed at one end of the electrode assembly facing the wall portion; An electrode terminal including a terminal body and a first flange, the terminal body passing through the electrode lead-out hole, the first flange protruding radially from the outer peripheral surface of the terminal body, and the first flange being located inside the wall portion to restrict the electrode terminal from moving in a direction away from the electrode assembly; A first current collector member located between the wall portion and the electrode assembly for connecting the electrode terminal and the first tab; Wherein, the terminal body has a first end face facing the first current collector member, the first end face is provided with a groove and a connection area for connecting with the first current collector member, and the groove is located between the connection area and the first flange; The battery cell is a cylindrical battery cell.

2. The battery cell according to claim 1, characterized in that, The groove is an annular groove provided around the outer periphery of the connection area.

3. The battery cell according to claim 2, wherein The electrode assembly is of a wound structure, and the first current collector member covers the winding center hole of the electrode assembly.

4. The battery cell according to claim 3, wherein, The first current collector member includes a current collector body and a protrusion, the protrusion protruding towards the electrode terminal from the current collector body, the protrusion corresponding to the position of the winding center hole of the electrode assembly and being used for connecting the connection area, and the current collector body being used for connecting the first tab; 5. The battery cell according to claim 4, characterized in that, The outer diameter of the groove is greater than the diameter of the protrusion.

6. The battery cell according to claim 4, characterized in that, The inner diameter of the groove is smaller than the diameter of the protrusion.

7. The battery cell according to claim 4, wherein, The protrusion includes an end wall and a peripheral wall, the peripheral wall surrounding the end wall, the peripheral wall being connected to the current collector body, the end wall being connected to the connection area, and the peripheral wall and the end wall jointly enclosing a cavity; 8. The battery cell according to claim 7, characterized in that, The diameter of the cavity is greater than the diameter of the winding center hole.

9. The battery cell according to any one of claims 1-8, characterized in that, One side of the electrode terminal facing the first current collector member forms an inclined surface, the inclined surface being inclined with respect to a plane perpendicular to the central axis direction of the electrode terminal and extending from the outer groove wall of the groove towards the direction close to the electrode assembly; 10. The battery cell according to any one of claims 1-8, characterized in that, The electrode terminal further includes a second flange, the second flange protruding radially from the outer peripheral surface of the terminal body, and the second flange being located outside the wall portion to restrict the electrode terminal from moving in a direction towards the electrode assembly; 11. The battery cell according to claim 10, characterized in that, The battery cell further includes an insulating member disposed between the electrode terminal and the wall portion to insulate and isolate the electrode terminal and the wall portion; 12. The battery cell according to claim 11, characterized in that, One side of the second flange facing the wall portion forms an annular protrusion, the annular protrusion being arranged around the central axis of the electrode terminal, and the annular protrusion being configured to squeeze the part of the insulating member located between the second flange and the wall portion; 13. The battery cell according to claim 12, characterized in that, In the thickness direction of the wall portion, the projection of the first flange on the second flange covers the annular protrusion.

14. The battery cell according to any one of claims 1-8, characterized in that, The outer shell includes a housing and an end cap. The housing includes a bottom wall and a side wall. The side wall surrounds the bottom wall. One end of the side wall is connected to the bottom wall, and the other end of the side wall encloses an opening opposite to the bottom wall. The end cap covers the opening. The wall portion is the bottom wall or the end cap.

15. The battery cell according to any one of claims 1-8, characterized in that, The electrode terminal is insulated from the wall portion. A second tab is formed at one end of the electrode assembly away from the wall portion. The second tab has a polarity opposite to that of the first tab. The battery cell further includes a second current collecting member for electrically connecting the second tab and the wall portion.

16. A battery, characterized in that, A battery cell including any one of claims 1 - 15.

17. An electrical device, characterized in that, A battery including claim 16.

18. A method for preparing a battery cell, wherein the battery cell is a cylindrical battery cell, characterized in that, Comprising: Providing an electrode assembly with a first tab formed at one end thereof. Providing a housing and an electrode terminal. The housing includes a bottom wall and a side wall. The side wall surrounds the bottom wall. One end of the side wall is connected to the bottom wall, and the other end of the side wall encloses an opening opposite to the bottom wall. The bottom wall is provided with an electrode lead - out hole. The electrode terminal includes a terminal body and a first flange. The terminal body passes through the electrode lead - out hole. The first flange protrudes radially from the outer peripheral surface of the terminal body. The first flange is located inside the bottom wall to limit the movement of the electrode terminal in the direction away from the electrode assembly. The terminal body has a first end face facing the inside of the housing. The first end face is provided with a groove and a connection area. The groove is located between the connection area and the first flange. Providing a first current collecting member and connecting the first current collecting member to the first tab. Placing the electrode assembly and the first current collecting member into the housing, and making the first current collecting member located between the bottom wall and the electrode assembly. Connecting the first current collecting member to the connection area. Providing an end cap and covering the opening of the housing with the end cap.

19. The preparation method of the battery cell according to claim 18, wherein, The step of connecting the first current collecting member to the first tab is completed before the step of placing the electrode assembly into the housing.

20. The method for preparing a battery cell according to claim 18 or 19, wherein The connecting the first current collecting member to the connection area includes: Entering the welding unit into the housing through the opening and passing through the winding center hole of the electrode assembly to weld the first current collecting member and the connection area.

21. A preparation device for a battery cell, wherein the battery cell is a cylindrical battery cell, characterized in that, Comprising: A first providing device for providing an electrode assembly with a first tab formed at one end thereof. A second providing device for providing a housing and electrode terminals, the housing including a bottom wall and a side wall, the side wall surrounding the bottom wall, one end of the side wall being connected to the bottom wall, the other end of the side wall enclosing an opening opposite to the bottom wall, the bottom wall being provided with an electrode lead-out hole, the electrode terminals including a terminal body and a first flange, the terminal body being inserted through the electrode lead-out hole, the first flange protruding radially from the outer peripheral surface of the terminal body along the terminal body, the first flange being located inside the bottom wall to limit the movement of the electrode terminals in a direction away from the electrode assembly, the terminal body having a first end face facing the interior of the housing, the first end face being provided with a groove and a connection area, the groove being located between the connection area and the first flange; A third providing device for providing a first current collector member; A fourth providing device for providing an end cap; And A first assembling device for connecting the first current collector member to the first tab; A second assembling device for placing the electrode assembly and the first current collector member into the housing and positioning the first current collector member between the bottom wall and the electrode assembly; A third assembling device for connecting the first current collector member to the connection area; A fourth assembling device for covering the opening of the housing with the end cap.

22. The preparation apparatus for the battery cell according to claim 21, wherein, The third assembling device is used for welding the first current collector member to the connection area, and the third assembling device includes a welding unit for entering the housing and passing through the winding center hole of the electrode assembly to weld the first current collector member and the connection area.

23. An assembling method for a housing and an electrode terminal, characterized in that, Comprising: Providing a housing, the housing being cylindrical, the housing including a bottom wall and a side wall, the side wall surrounding the bottom wall, one end of the side wall being connected to the bottom wall, the other end of the side wall enclosing an opening opposite to the bottom wall, the bottom wall being provided with an electrode lead-out hole; Providing electrode terminals, the electrode terminals including a terminal body and a first flange, the terminal body having a first end face, the first flange protruding from the first end face along the central axis direction of the terminal body, the first flange surrounding the first end face, the first end face being provided with a groove and a connection area, the groove being located between the connection area and the first flange; Inserting the electrode terminals through the electrode lead-out hole, positioning the first flange inside the bottom wall, and bending the first flange so that the first flange protrudes radially from the outer peripheral surface of the terminal body along the electrode terminals to limit the movement of the electrode terminals to the outside of the bottom wall through the first flange.

24. An assembly device for a housing and an electrode terminal, characterized in that, Comprising: A fifth providing device for providing a housing, the housing being cylindrical, the housing including a bottom wall and a side wall, the side wall surrounding the bottom wall, one end of the side wall being connected to the bottom wall, the other end of the side wall enclosing an opening opposite to the bottom wall, the bottom wall being provided with an electrode lead-out hole; A sixth providing device for providing an electrode terminal, the electrode terminal including a terminal body and a first flange, the terminal body having a first end face, the first flange protruding from the first end face along a central axis direction of the terminal body, the first flange being disposed around the first end face, the first end face being provided with a groove and a connection area, the groove being located between the connection area and the first flange; A fifth assembling device for passing the electrode terminal through the electrode lead-out hole, such that the first flange is located inside the bottom wall, and bending the first flange so that the first flange protrudes from an outer peripheral surface of the terminal body along a radial direction of the electrode terminal, so as to limit outward movement of the electrode terminal relative to the bottom wall by means of the first flange.

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