Battery cell, method for manufacturing a battery cell, battery and electrical device

Abstract

A battery cell (100), a method for manufacturing a battery cell (100), a battery (1000), and an electrical device, wherein the battery cell (100) includes a housing (10) including a first wall (11), an electrode post (20) provided on the first wall (11) and having a through hole (211), a cover plate (40) provided on one side of the electrode post (20) and covering one end corresponding to the through hole (211), and an electrode assembly (30) including an active material coated portion (31) and a conductive portion (32) connected to the active material coated portion (31), wherein the active material coated portion (31) is provided inside the housing (10), at least a part of the conductive portion (32) is provided inside the through hole (211) and connected to the cover plate (40).

Description

Technical Field

[0001] [Cross - reference to Related Applications] This application is based on a Chinese patent application with application number 202311309588.4 and filing date October 10, 2023, and claims the priority of the Chinese patent application. All the contents of the Chinese patent application are incorporated herein by reference.

[0002] This application relates to the field of battery technology, particularly to battery cells, manufacturing methods of battery cells, batteries, and electrical devices.

Background Art

[0003] As environmental problems become more serious, with the maturity of people's environmental protection awareness and the increase in oil prices, more and more people pay attention to new energy vehicles when purchasing vehicles. The superiority and inferiority in the endurance field and power performance field of new energy vehicles have an important impact on people's choices. Currently, in most new energy vehicles, power batteries are used as energy storage and kinetic energy devices, and in other types of vehicles, it is also impossible to avoid using power batteries. Since the battery energy density of power batteries has an important impact on both the endurance and power performance of vehicles, improving the energy density of batteries is an important research trend that should always be noted in the process of continuous improvement and innovation of batteries.

[0004] Currently, there is still an expectation to improve the energy density of batteries.

Summary of the Invention

[0005] The objective of this application is to solve at least one technical problem existing in the prior art. Therefore, this application provides a battery cell, which can improve the volume energy density and weight energy density of the battery cell, further reduce the probability of the battery cell short - circuiting, and improve the operational reliability and stability of the battery cell and the battery.

[0006] This application further provides a manufacturing method of the battery cell.

[0007] This invention further provides a battery having the above-mentioned battery cell.

[0008] The present invention further provides an electrical device having the above-mentioned battery.

[0009] A battery cell according to a first aspect of the present application includes a housing including a first wall, an electrode post provided in the first wall and having a through hole, a cover plate provided on one side of the electrode post and covering one end corresponding to the through hole, and an electrode assembly including an active material coated portion and a conductive portion connected to the active material coated portion, wherein the active material coated portion is provided in the housing, and at least a portion of the conductive portion is provided in the through hole and connected to the cover plate.

[0010] The battery cell according to this invention has through holes in the poles, and at least a portion of the conductive part is provided within the through holes. This reduces the space occupied by the conductive part inside the housing, allowing a larger active material coated part to be housed in the housing cavity, improving the volumetric energy density of the battery cell. Furthermore, it reduces redundancy within the housing of the conductive part, lowers the probability of a short circuit between the conductive part and the active material coated part, reduces the probability of a short circuit in the battery cell, and improves the operational reliability and stability of the battery cell and battery. In addition, by providing through holes inside the poles, the weight of the poles can be reduced, improving the gravimetric energy density of the battery cell and battery.

[0011] According to one example of this invention, the cover plate is welded to the conductive portion.

[0012] In this embodiment, the cover plate and the conductive part are connected by welding, thereby improving the connection strength and stability between the cover plate and the conductive part, further improving the stability of the electrical connection between the conductive part and the electrode pole, and at the same time reducing the complexity of the connection between the cover plate and the conductive part, thereby reducing the production cost and overall weight of the battery cell.

[0013] According to one example of the present invention, the cover plate has a first welding region and a second welding region, the first welding region being welded to the conductive portion, and the second welding region being used to weld an electrical connecting piece, wherein the first welding region and the second welding region are different regions of the cover plate.

[0014] This embodiment provides a first welding area and a second welding area, thereby limiting the welding positions of the conductive part and the electrical connection piece, improving the ease and reliability of battery cell assembly. Furthermore, by providing the first and second welding areas as different areas of the cover plate, it is possible to effectively prevent the problem of reduced welding quality due to the connection of the two molten pools, thereby improving the welding quality between the conductive part, the electrical connection piece, and the cover plate, and consequently improving the stability of the electrical connection of the battery cell.

[0015] According to one example of the present invention, the first welding area and the second welding area are formed on both sides of a center line perpendicular to the length or width of the cover plate, respectively.

[0016] In this embodiment, the first and second welding regions are formed on both sides of a center line perpendicular to the length or width of the cover plate, respectively. By forming the first and second welding regions on both sides of a center line perpendicular to the length or width of the cover plate, the positions of the first and second welding regions can be further restricted, thereby improving the ease and reliability of battery cell assembly.

[0017] According to one example of the present invention, the distance between the first welding area and the second welding area is two-thirds or less of the width of the cover plate, and / or the distance between the first welding area and the second welding area is one-third or more of the width of the cover plate.

[0018] In this embodiment, by setting the distance between the first and second welding areas to two-thirds or less of the width of the cover plate, the distance between the first and second welding areas is not too large, which is advantageous in securing the welding area on the cover plate for both the first and second welding areas. This facilitates the connection between the conductive parts and electrical connection pieces and the cover plate, guarantees the welding quality between the conductive parts and electrical connection pieces and the cover plate, and thereby improves the stability of the electrical connection of the battery cell. At the same time, by setting the distance between the first and second welding areas to one-third or more of the width of the cover plate, the distance between the first and second welding areas is not too small, effectively preventing the problem of reduced welding quality due to the connection of the two molten pools, improving the welding quality between the conductive parts and electrical connection pieces and the cover plate, and thereby improving the stability of the electrical connection of the battery cell.

[0019] According to one example of the present invention, the distance between the first welding area and the second welding area is 2 mm or more.

[0020] In this embodiment, by setting the distance between the first and second welding areas to 2 mm or more, the problem of reduced welding quality due to the connection of the two molten pools can be effectively prevented, the welding quality between the conductive parts and electrical connection pieces and the cover plate can be improved, and the stability of the electrical connection of the battery cell can be improved.

[0021] In one example of the present invention, the first welding region and the conductive portion are welded together to form a first molten pool, the second welding region and the electrical connecting piece are welded together to form a second molten pool, and the first and second molten pools are spaced apart.

[0022] In this embodiment, by setting the first and second molten pools to be spaced apart, the problem of the first and second molten pools connecting can be effectively solved, the welding quality between the conductive parts and electrical connection pieces and the cover plate can be improved, and the stability of the electrical connection of the battery cell can be improved.

[0023] According to an example of the present application, the ratio of the thickness of the cover plate to the thickness of the first wall is 1 to 4. Optionally, the ratio of the thickness of the cover plate to the thickness of the first wall is 2 to 3. Optionally, the thickness of the cover plate is 1.5 mm or more and 5 mm or less.

[0024] In this embodiment, by setting the ratio of the thickness of the cover plate to the thickness of the first wall to 1 to 4, not only can the thickness of the cover plate meet the requirements for welding the conductive part and the electrical connection piece, but also the thickness of the cover plate can be prevented from becoming too large, which is helpful for reducing the weight of the battery cell.

[0025] In this embodiment, by setting the ratio of the thickness of the cover plate to the thickness of the first wall to 2 to 3, the thickness of the cover plate is further limited, so that the thickness of the cover plate does not become too large, which is helpful for reducing the weight of the battery cell. At the same time, the thickness of the cover plate does not become too small, and the requirements for welding the conductive part and the electrical connection piece and the requirements for the structural strength of the battery cell can be met.

[0026] In this embodiment, by setting the thickness of the cover plate to be 1.5 mm or more and 5 mm or less, the thickness of the cover plate can meet the requirements for welding the conductive part and the electrical connection piece, and at the same time, the thickness of the cover plate can be restricted from becoming too large, reducing the occupation of the internal space of the through hole by the cover plate, and improving the space utilization rate of the battery cell.

[0027] According to an example of the present application, the cover plate includes a cover plate body and a boss. The cover plate body covers the one end of the through hole. The boss is provided on the surface of one side of the cover plate body facing the electrode assembly, and enters into the through hole, and the conductive part is connected to the boss.

[0028] In this embodiment, by providing the cover plate body and the boss, the sealing effect between the cover plate and the pole can be improved, the risk of electrolyte leakage from the through hole can be further reduced, the reliability of the battery cell can be improved, and the occurrence of the situation where the molten pools generated in the welding process are connected can be further reduced. The welding quality of the conductive part and the electrical connection piece with the cover plate can be further improved, thereby improving the stability of the electrical connection of the battery cell.

[0029] According to an example of the present application, the height at which the boss protrudes from the surface of one side of the cover plate body is 1 mm to 5 mm, and optionally, 1.5 mm to 3 mm.

[0030] In this embodiment, by setting the height at which the boss protrudes from the surface of one side of the cover plate body to be 1 mm to 5 mm, the thickness of the boss does not become too large, which helps to reduce the occupation of the internal space of the through hole by the cover plate, improve the space utilization rate of the battery cell, and the thickness of the boss does not become too small. Thereby, the thickness of the boss meets the requirements of the welding of the conductive part and improves the stability of the connection between the conductive part and the boss.

[0031] In this embodiment, by setting the height at which the boss protrudes from the surface of one side of the cover plate body to be 1.5 mm to 3 mm, the thickness of the boss can meet the requirements of the welding of the conductive part, and the occupation of the internal space of the through hole by the cover plate can be further reduced, and the space utilization rate of the battery cell can be further improved.

[0032] According to an example of the present application, the boss is clearance-fitted at one end of the through hole, and the fitting clearance between the boss and the through hole is 0 to 0.1 mm.

[0033] In this embodiment, by clearance-fitting the boss at one end of the through hole and setting the fitting clearance between the boss and the through hole to be 0 to 0.1 mm, it helps to insert and remove the boss from the through hole, and the difficulty of assembling the cover plate and the pole can be reduced.

[0034] According to one example of this application, the fitting gap between the boss and the through hole is 0.05 mm or less.

[0035] In this embodiment, by setting the fitting gap between the boss and the through-hole to 0.05 mm or less, the gap between the boss and the inner wall of the through-hole can be further reduced, the sealing effect of the through-hole by the boss can be further improved, the risk of electrolyte leakage from the cover plate can be reduced, and the reliability of the battery cell can be improved.

[0036] According to one example of the present invention, the electrode column is a negative electrode column, the cover plate body and the boss are separate components, the cover plate body and the boss are made of different materials, the boss is made of the same material as the conductive part, and when the boss is welded to the conductive part, the depth of the molten pool on the cover plate is less than the thickness of the boss.

[0037] In this embodiment, the pole is the negative pole, the cover plate body and the boss are separate components, and the material of the boss and the conductive part are the same. By matching the material of the boss and the conductive part, the welding quality between the boss and the conductive part can be improved, and the connection stability between the boss and the conductive part can be improved. Furthermore, when welding the boss to the conductive part, the depth of the molten pool on the cover plate is smaller than the thickness of the boss, and by controlling the welding position between the same material, the welding quality between the boss and the conductive part can be further improved, and the difficulty of welding the boss and the conductive part can be reduced.

[0038] According to one example of the present invention, the pole column is a positive pole column, the boss and the cover plate body are integrally molded, and when the cover plate is welded to the conductive part, the depth of the molten pool on the boss is greater than the thickness of the boss.

[0039] In this embodiment, when the pole is a positive pole, the boss and the cover plate body are integrally molded, thereby the cover plate satisfies the need for welding between the electrical connection piece and the conductive part, reduces the production process of the cover plate, shortens the production steps of the cover plate, improves the production speed of the cover plate, and lowers the production cost of the cover plate.

[0040] According to one example of this invention, the pole column is welded to the cover plate.

[0041] In this embodiment, by arranging the poles so as to be welded to the cover plate, the connection stability and sealing performance between the poles and the cover plate can be improved, thereby improving the airtightness of the battery cell and enhancing the reliability of the battery cell.

[0042] According to one example of the present invention, the pole column is a hollow annular shape and the through hole is defined on its inner side.

[0043] In this embodiment, by making the pole column a hollow annular shape and defining a through hole on the inside, the weight of the pole column can be reduced to some extent, improving the gravimetric energy density of the battery cell and the battery. Furthermore, the large volume of the internal cavity of the hollow annular shape allows the conductive part to extend very easily from the through hole, reducing the difficulty of welding the conductive part to the cover plate, reducing the difficulty of assembling the battery cell, and improving the assembly speed of the battery cell.

[0044] According to one example of the present invention, the pole column includes a pole column body, a first ring, and a second ring, wherein the pole column body is annular and has the through hole defined on its interior, the first ring is connected to one end of the pole column body facing the electrode assembly, the first ring extends outward along the radial direction of the pole column body and extends annularly along the circumferential direction of the pole column body, and the second ring is connected to the other end of the pole column body opposite to the electrode assembly, the second ring extends outward along the radial direction of the pole column body and extends annularly along the circumferential direction of the pole column body.

[0045] In this embodiment, by providing a first ring and a second ring at each end of the pole post body, the first and second rings can improve the structural strength of the pole post body to some extent, thereby improving the overall structural strength of the pole post, making the connection and fixing of the pole post and tab more stable and secure, and allowing the pole post to participate more effectively in the task of transmitting electrical energy from the battery cell. The first and second rings can engage with the pole post body to form a locking groove structure, thereby facilitating the attachment and fixing of the pole post in the battery cell, and the structure of the first and second rings is simple and easy to use.

[0046] According to one example of the present invention, a groove is formed on the surface of the pole column opposite to the electrode assembly, the through hole is formed inside the groove and penetrates the bottom wall of the groove, and the cover plate is provided inside the groove.

[0047] In this embodiment, by forming a groove on the surface of the pole column opposite to the electrode assembly, positioning is easier when fixing the cover plate and the pole column, and the connection and fixing are stable and reliable.

[0048] According to one example of the present invention, in the direction from the electrode assembly toward the cover plate, the side wall of the groove extends inclined outward along the radial direction of the through hole.

[0049] In this embodiment, the side walls of the groove are provided to incline outward along the radial direction of the through hole, which provides a certain guiding effect when assembling the cover plate and pole column, allowing the cover plate to be easily fixed in the groove, resulting in a simple structure and ease of assembly. At the same time, when the cover plate is welded to the pole column, the periphery of the cover plate and the inclined side walls of the groove can further widen the welding width during welding, thereby resulting in a high welding quality between the cover plate and pole column, improving the welded sealing effect between the cover plate and pole column, and improving the sealing performance of the battery cell.

[0050] According to one example of the present invention, the surface of the cover plate on the side opposite to the electrode assembly is flush with the end face of the pole column on the side opposite to the electrode assembly.

[0051] In this embodiment, by arranging the cover plate so that the surface on the side opposite to the electrode assembly and the end face of the pole opposite to the electrode assembly are flush, the cover plate and the pole can be combined to form a continuous plane. This reduces the space occupied by the cover plate to some extent and increases the electrical connection surface of the pole of the battery cell, thereby increasing the energy density of the battery cell to some extent. The battery cell can also be easily electrically connected to an electrical connection member via the end of the pole opposite to the electrode assembly, and at the same time, the aesthetic appearance of the battery cell can be improved.

[0052] According to one example of the present invention, the active material coated portion includes a current collector and an active material layer provided on the current collector, the conductive portion includes a tab portion electrically connected to the current collector, the tab portion includes a plurality of tab pieces, the tab pieces closer to the current collector are bundled together to form a first convergence portion, the tab pieces further from the current collector are bundled and connected to form a second convergence portion, the first convergence portion connects the second convergence portion and the active material coated portion, and at least a portion of the second convergence portion is housed in the through hole.

[0053] In this embodiment, by arranging the components so that multiple tab pieces are bundled and connected to form a second convergence section, the size and thickness of the second convergence section can be reduced, allowing the tab pieces to be easily inserted into the through-holes and connected to the cover plate, thereby improving the ease of connection between the conductive part and the cover plate. At the same time, the branching of the multiple tab pieces effectively reduces the risk of reverse insertion of tab pieces and short-circuiting with the active material coated area below the tab pieces, thereby improving the reliability of the battery cell. Furthermore, by arranging the components so that at least a portion of the second convergence section is housed within the through-holes, the space of the pole columns can be fully utilized, improving the volumetric energy density of the battery cell.

[0054] According to one example of the present invention, the conductive portion is fixedly connected to the cover plate via the second convergence portion.

[0055] In this embodiment, by arranging the conductive part to be fixedly connected to the cover plate via the second convergence part, the structure of the battery cell can be simplified, the use of parts can be reduced, the assembly flow can be simplified, and the assembly efficiency can be improved.

[0056] According to one example of the present invention, at least a portion of the first convergence portion is housed within the through-hole.

[0057] In this embodiment, by arranging the first convergence portion to be housed within the through-hole, the space within the pole column can be utilized more fully, the space occupied within the housing of the tab portion can be further reduced, a larger active material coating portion can be accommodated, improving the volumetric energy density of the battery cell, and redundancy within the housing of the tab portion can be effectively reduced, further lowering the probability of a short circuit between the tab portion and the active material coating portion.

[0058] According to one example of the present invention, the active material coated portion includes a current collector and an active material layer provided on the current collector, the conductive portion includes a tab portion electrically connected to the current collector, the tab portion includes a plurality of tab pieces, the tab pieces closer to the current collector are bundled together to form a first convergence portion, the tab pieces further away from the current collector are bundled and connected to form a second convergence portion, the first convergence portion connects the second convergence portion and the active material coated portion, the conductive portion further includes a connecting piece, the connecting piece is connected to the second convergence portion, the conductive portion is electrically connected to the cover plate via the connecting piece, and at least a portion of the connecting piece is housed in the through hole.

[0059] In this embodiment, by providing a connecting piece, at least a portion of the second convergence section and at least a portion of the connecting piece can be housed within the through-hole, allowing for more efficient use of the space within the pole column, further reducing the space occupied within the housing of the conductive part, and improving the volumetric energy density of the battery cell. At the same time, the portion of the connecting piece that avoids the second convergence section can be welded to the pole column, thereby making the weld between the connecting piece and the pole column more robust, reducing the risk of welding cracks, and further improving the reliability and stability of the battery cell. Simultaneously, by electrically connecting the pole column and the tab piece via the connecting piece, the structure of the tab piece can be simplified.

[0060] According to one example of the present invention, at least a portion of the second convergence portion is located within the through-hole, or the entire second convergence portion is located within the through-hole and at least a portion of the first convergence portion is located within the through-hole.

[0061] In this embodiment, by arranging the second convergence portion so that at least a part of it is located within the through-hole, the space within the pole column can be fully utilized, the space occupied by the tab portion within the housing can be further reduced, and the volumetric energy density of the battery cell can be improved. By arranging the second convergence portion so that it is entirely located within the through-hole and at least a part of the first convergence portion is located within the through-hole, the space within the pole column can be fully utilized, the space occupied by the tab portion within the housing can be significantly reduced, and the volumetric energy density of the battery cell can be significantly improved. At the same time, redundancy within the housing of the tab portion can be further reduced, and the probability of a short circuit between the tab portion and the active material coated portion can be further reduced.

[0062] According to one example of the present invention, the second convergence portion extends along the surface of the cover plate, and in the direction from the electrode assembly toward the cover plate, one end of the first convergence portion is connected to the active material coating portion, and the other end of the first convergence portion extends inclined toward the peripheral wall of the through hole and extends to one end of the second convergence portion and is connected thereto.

[0063] In this embodiment, the second convergence portion extends along the surface of the cover plate, and in the direction from the electrode assembly toward the cover plate, one end of the first convergence portion is connected to the active material coating portion, and the other end of the first convergence portion extends inclined toward the peripheral wall of the through hole and extends to one end of the second convergence portion and connects to it. This increases the length of the first convergence portion that can be accommodated inside the through hole, effectively reduces the space occupied by the tab inside the battery cell, allows for the accommodation of a larger active material coating portion, improves the volumetric energy density of the battery cell, effectively reduces redundancy of the tab portion within the housing, and further reduces the probability of a short circuit between the tab portion and the active material coating portion, thereby improving the stability of the battery cell.

[0064] A method for manufacturing a battery cell according to a second aspect of the present application, the manufacturing method comprising: passing one end of a conductive portion through a through hole in an electrode column and extending it from the other side of the electrode column; welding the one end of the conductive portion to a cover plate on the other side of the electrode column; placing the cover plate over one end of the through hole to house the conductive portion within the through hole; and fixing the cover plate to the electrode column.

[0065] According to the battery cell manufacturing method of the present invention, the cover plate and the conductive part can be welded together on the outside of the battery cell. This reduces damage to the battery cell caused by slag falling into the battery cell during the welding process, thereby improving the reliability of the battery cell. At the same time, by housing the conductive part within a through hole, the space occupied by the conductive part inside the housing is reduced, allowing a larger volume of the active material coated part to be housed in the housing, thereby improving the energy density of the battery cell. Furthermore, the redundancy of the conductive part is reduced, the probability of a short circuit between the conductive part and the active material coated part is decreased, and the stability of the battery cell can be improved.

[0066] According to one example of the present invention, welding one end of the conductive part to the cover plate on the other side of the pole column includes pressing the other end of the conductive part to the surface of one side of the cover plate and laser welding the other end of the conductive part to the cover plate.

[0067] This embodiment improves welding quality by securing a welding gap and enabling laser welding by pressing the other end of the conductive part against the surface of one side of the cover plate. By welding the conductive part and the cover plate using a laser, the connection speed between the conductive part and the cover plate can be improved, and the welding quality between the conductive part and the cover plate can be improved.

[0068] A battery according to a third aspect of the present application, which includes a battery cell according to the first aspect of the present application, or a battery cell manufactured by a method for manufacturing a battery cell according to the second aspect of the present application.

[0069] The battery of the present invention improves the overall performance of the battery by providing a battery cell manufactured by the battery cell manufacturing method of the first embodiment or the battery cell manufacturing method of the second embodiment.

[0070] An electrical device according to a fourth aspect of the present application, comprising a battery according to a third aspect of the present application for supplying electrical energy.

[0071] According to the electrical device of the present invention, the overall performance of the electrical device is improved by providing the battery of the third embodiment described above.

[0072] Additional aspects and advantages of the present application are, in part, described below, and in part, become apparent from the following description or are understood by implementing the present application. [Brief explanation of the drawing]

[0073] [Figure 1] This is a schematic diagram of a vehicle according to an embodiment of the present invention. [Figure 2] This is an exploded view of a battery according to an embodiment of the present invention. [Figure 3] This is a schematic diagram of a portion of a battery cell according to an embodiment of the present invention. [Figure 4] This is a schematic diagram of a battery cell in another state according to an embodiment of the present invention, where the battery cell has been assembled. [Figure 5] This is a schematic diagram of yet another state of the battery cell according to an embodiment of the present invention, in which the cover plate covers the through hole. [Figure 6] Figure 5 is a schematic diagram of the cover plate shown. [Figure 7] Figure 5 is a schematic diagram of the polar column shown. [Figure 8] Figure 5 is a schematic diagram of another angle of the pole column shown. [Figure 9] Figure 5 is a schematic diagram of the polar column at yet another angle. [Figure 10] Figure 5 is a schematic diagram of the polar column at yet another angle. [Figure 11]This is a schematic diagram of the assembly of a battery cell according to an embodiment of the present invention. [Figure 12] This is a schematic diagram of another assembly state of the battery cell according to the embodiment of the present application, in which one end of the conductive part extends from a through hole. [Figure 13] This is a schematic diagram of yet another assembly state of the battery cell according to the embodiment of the present invention, in which the conductive part is laser-welded to the cover plate. [Figure 14] Figure 3 is a schematic diagram of the electrode assembly shown. [Modes for carrying out the invention]

[0074] The following examples of embodiments of the technical solution of the present application will be described in detail with reference to the drawings. The following embodiments are used solely to illustrate the technical solution of the present application more clearly and are merely examples, and do not limit the scope of protection of the present application.

[0075] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application pertains, and the terms used herein are intended solely to describe specific embodiments and are not intended to limit this application. The terms “including” and “having” and their synonyms in the description and claims of this application and in the description of the drawings above are intended to be non-exclusive.

[0076] In the description of the embodiments of this application, terms such as "first," "second," etc., are merely used to distinguish different objects and should not be understood as implicitly indicating the quantity, specific order, or hierarchical relationship of technical features of relative importance, or that which have been shown. In the description of the embodiments of this application, unless otherwise specifically limited, "multiple" means two or more.

[0077] References to “Examples” in this specification mean that certain features, structures, or properties described in relation to the Examples may be included in at least one Example of the Application. Where the term “Examples” appears elsewhere in this specification, it does not necessarily refer to the same Example, nor does it refer to an Example that is mutually exclusive, independent, or substitutable with other Examples. Those skilled in the art will understand, both explicitly and implicitly, that the Examples described herein can be combined with other Examples.

[0078] The term "and / or" in the description of the embodiments of this application merely describes the relationship between related objects, indicating that three types of relationships are possible. For example, A and / or B can represent three situations: A existing alone, A and B existing simultaneously, and B existing alone. In this specification, the symbol " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0079] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two).

[0080] In the description of the embodiments of this application, the directions or positional relationships indicated by terms such as "center," "vertical direction," "horizontal direction," "length," "width," "thickness," "top," "bottom," "front," "back," "left," "right," "vertical," "horizontal," "upper part," "bottom," "inside," "outside," "axial direction," "radial direction," and "circumferential direction" are merely intended to facilitate the explanation of the embodiments of this application and to simplify the explanation, based on the directions or positional relationships shown in the drawings. They do not indicate or imply that the device or element in question has a specific direction, or that it should be composed of and operated in a specific direction, and therefore should not be understood as limiting the embodiments of this application.

[0081] In the description of the embodiments of this application, unless otherwise specifically defined and limited, terms such as “attached,” “connected,” “bonded,” and “fixed” should be understood in a broad sense. For example, they may be fixed connections, detachable connections, or integral connections. They may be mechanical connections or electrical connections. They may be directly connected, indirectly connected via an intermediate medium, or be internal communication between two elements or an interaction relationship between two components. Those skilled in the art will be able to understand the specific meaning of the above terms in the embodiments of this application depending on the specific circumstances.

[0082] Currently, with the evolving market conditions, the applications of power batteries are expanding rapidly. Power batteries are not limited to applications in energy storage and power systems such as hydroelectric, thermal, wind, and solar power plants, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in multiple fields such as military equipment and aerospace. As the application fields of power batteries continue to expand, the demand for them in the market is also constantly growing.

[0083] In related technologies, battery cells are manufactured by applying an active material layer to a current collector and then cutting it to obtain a polarity sheet consisting of a current collector with the active material layer applied (referred to as the active material coated portion) and a current collector without the active material layer applied (referred to as a tab piece). Next, the positive and negative polarity sheets and separators are sequentially laminated or wound to obtain an electrode assembly, and multiple tab piece layers in the electrode assembly are laminated to form tab portions. Electrode columns are provided in the housing of the battery cell, and the surface of the electrode column facing the active material coated portion is the inner end surface of the electrode column. During manufacturing, the battery cell is usually manufactured by directly welding the tab portion to the inner end surface of the electrode column, or by indirectly welding it to the inner end surface of the electrode column via a connecting piece, to ensure the normal progress of charging and discharging operations.

[0084] However, when a battery cell employs the above structure, both the tab portion and the connecting piece accumulate between the active material coating area and the inner end face of the electrode post, occupying a large space. If the housing size is constant, this prevents increasing the size of the active material coating area, making it difficult to improve the energy density of the battery cell. Furthermore, due to design or manufacturing reasons, the length of the tab portion is generally long, and if the space between the active material coating area and the inner end face of the electrode post is narrow, a problem of tab portion redundancy arises after the electrode assembly is placed in the housing. This easily causes short circuits between the tab portion or connecting piece and the active material coating area, affecting the reliability and stability of the battery cell.

[0085] Based on the above considerations, in order to reduce the space occupied by the tabs and improve the energy density of the battery cell, the present invention provides a battery cell in which through holes are provided inside the poles of the battery cell, and at least a portion of the conductive part is provided inside the through holes, thereby reducing the space occupied by that portion within the housing, and thereby allowing the active material coated portion to be housed in more space saved within the housing, increasing the volume of the active material coated portion, which is advantageous in improving the energy density of the battery cell, and also reduces the redundancy of the tab portion or connecting piece within the housing, reduces the probability of short circuits between the tab portion or connecting piece and the active material coated portion, reduces the probability of several reliability-related problems caused by short circuits, and improves the operational reliability and stability of the battery cell and battery.

[0086] The battery cells disclosed in the embodiments of this application can be used in electrical devices that use batteries as a power source or in various energy storage systems that use batteries as energy storage elements. Electrical devices may include, but are not limited to, mobile phones, tablets, laptop computers, electric toys, power tools, battery cars, electric vehicles, ships, and spacecraft. Electric toys may include stationary or mobile electric toys such as game consoles, electric car toys, electric boat toys and electric aircraft toys, and spacecraft may include aircraft, rockets, space shuttles and spacecraft.

[0087] In the following embodiments, for the sake of explanation, the electrical device of the embodiment of the present application will be described as Vehicle 1.

[0088] Referring to Figure 1, which is a schematic diagram of a vehicle 1 according to several embodiments of the present application, the vehicle 1 may be a gasoline vehicle, a natural gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or a range extender vehicle, etc. A battery 1000 is provided inside the vehicle 1, and the battery 1000 may be located at the bottom, front, or rear of the vehicle 1. The battery 1000 can be used to supply power to the vehicle 1, for example, as the operating power source for the vehicle 1. The vehicle 1 may further include a controller 2000 and a motor 3000, the controller 2000 is used to control the battery 1000 to supply power to the motor 3000, for example, to meet the operating power requirements for starting, navigation, and driving the vehicle 1.

[0089] In some embodiments of the present invention, the battery 1000 can provide driving power to the vehicle 1 not only as an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, by substituting or partially substituting fuel or natural gas.

[0090] Referring to Figure 2, which is an exploded view of a battery 1000 according to several embodiments of the present invention, the battery 1000 includes a housing 200 and a battery cell 100, the housing 200 having a cavity, and the battery cell 100 being housed in the cavity of the housing 200. The housing 200 is used to provide a housing space for the battery cell 100, and the housing 200 can employ various structures. In some embodiments, the housing 200 may include a first part (e.g., the main housing 201 described below) and a second part (e.g., the end cover 202 described below), and by overlapping the first part and the second part with each other, the first part and the second part together define a housing space for housing the battery cell 100. The second part is a hollow structure with one end open, and the first part is a plate-like structure, and the first part may be placed over the open side of the second part, so that the first part and the second part together define a housing space. Alternatively, both the first and second parts may be hollow structures with one side open, and the open side of the first part may be fitted over the open side of the second part. Naturally, the housing 200 formed by the first and second parts may have various shapes such as a cylinder or a rectangular parallelepiped.

[0091] In the battery 1000, there may be multiple battery cells 100, and the multiple battery cells 100 can be connected in series, in parallel, or in series-parallel. Series-parallel connection means that the multiple battery cells 100 can be connected in both series and parallel. Multiple battery cells 100 can be directly connected in series, in parallel, or in series-parallel, and then the entire assembly composed of multiple battery cells 100 can be housed in the housing 200. Alternatively, the battery 1000 may first be formed in the form of a battery module by connecting multiple battery cells 100 in series, in parallel, or in series-parallel, and then the multiple battery modules may be further connected in series, in parallel, or in series-parallel to form a single unit which can then be housed in the housing 200. The battery 1000 may further include other structures, such as bus members for realizing electrical connections between multiple battery cells 100.

[0092] Each battery cell 100 may be a secondary battery or a primary battery, and may be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 100 may be cylindrical, flattened, rectangular, or have other shapes.

[0093] The battery cell 100 according to an embodiment of the first aspect of the present application will be described below with reference to Figures 3 to 14. Figure 3 is a schematic partial view of the battery cell 100 according to some embodiments of the present application, Figure 4 is a schematic partial view of the battery cell 100 according to some embodiments of the present application in another state, where the battery cell 100 is fully assembled, Figure 5 is a schematic partial view of the battery cell 100 according to some embodiments of the present application in yet another state, where the cover plate 40 covers the through hole 211, Figure 6 is a schematic view of the cover plate 40 shown in Figure 5, Figure 7 is a schematic view of the pole column 20 shown in Figure 5, Figure 8 is a schematic view of the pole column 20 shown in Figure 5 at a different angle, and Figure 9 is a schematic view of the pole column shown in Figure 5. Figure 10 is a schematic diagram of the pole column 20 shown in Figure 5 from yet another angle, Figure 11 is a schematic assembly diagram of the battery cell 100 according to some embodiments of the present application, Figure 12 is a schematic assembly diagram of the battery cell 100 according to some embodiments of the present application in another state, where one end of the conductive portion 32 extends from the through hole 211, Figure 13 is a schematic assembly diagram of the battery cell 100 according to some embodiments of the present application in yet another state, where the conductive portion 32 is laser-welded to the cover plate 40, and Figure 14 is a schematic diagram of the electrode assembly 30 shown in Figure 3.

[0094] An embodiment of the present invention provides a battery cell 100, as shown in Figure 3, which comprises a housing 10, an electrode post 20, a cover plate 40, and an electrode assembly 30, specifically, the housing 10 comprises a first wall 11, the electrode post 20 is provided in the first wall 11 and has a through hole 211, the cover plate 40 is provided on one side of the electrode post 20 and covers the corresponding end of the through hole 211, and the electrode assembly 30 comprises an active material coated portion 31 and a conductive portion 32 connected to the active material coated portion 31, the active material coated portion 31 is provided inside the housing 10 and at least a portion of the conductive portion 32 is provided inside the through hole 211 and connected to the cover plate 40.

[0095] The shape of the housing 10 can be adjusted according to the type of battery cell 100. For example, if the battery cell 100 is a prismatic battery 1000, the housing 10 is prismatic, and if the battery cell 100 is a cylindrical battery 1000, the housing 10 is cylindrical. The embodiments of this application will be described using the example that the housing 10 is prismatic. As shown in Figure 3, the housing 10 may be an aluminum case, a stainless steel case, etc., and the housing 10 is used to house the electrode assembly 30 in the battery cell 100 and to fix the pole post 20. The first wall 11 of the housing 10 is formed at one end in the longitudinal direction of the housing 10 (for example, the vertical direction shown in Figure 3), and when assembling the battery cell 100, the electrode assembly 30 can be placed in the housing cavity of the housing 10, and the pole post 20 is fixed to the first wall 11 of the housing 10. Specifically, the first wall 11 of the housing 10 is provided along the thickness direction of the first wall 11 (for example, the vertical direction shown in Figure 3) and can pass through the mounting holes of the first wall 11, and the pole post 20 is provided in the mounting holes and fixedly connected to the housing 10, for example the pole post 20 and the housing 10 may be fixed by welding or riveting.

[0096] The poles 20 are used to connect the battery cell 100 to the electrical connection member and transmit electrical energy. The material of the poles 20 may be copper, aluminum, zinc, or alloys thereof, and the shape of the poles 20 may be circular, rectangular, or other shapes as needed in the design. Generally, there are at least two poles 20, specifically, at least one positive pole and at least one negative pole. For example, if there are two poles 20, one is a positive pole and one is a negative pole, and both are electrically connected to the positive and negative tabs of the electrode assembly 30. Furthermore, if there are four poles 20, for example, two may be positive poles and two may be negative poles. In this case, both positive poles are electrically connected to the positive tab of the electrode assembly 30, and both negative poles are electrically connected to the negative tab of the electrode assembly 30.

[0097] The cover plate 40 is used to cover the through-hole 211 by being sealed and connected to the pole post 20, thereby sealing the battery cell 100, isolating the inside and outside of the battery cell 100, and improving the reliability of the battery cell 100. At the same time, the conductive part 32 is electrically connected to the cover plate 40, and the cover plate 40 is connected to the pole post 20, thereby realizing an electrical connection between the conductive part 32 and the pole post 20, and realizing the transmission of electrical energy from the battery cell 100. Selectively, the material of the cover plate 40 may match the material of the pole post 20, and the shape of the cover plate 40 may be designed according to the shape of the through-hole 211.

[0098] The electrode assembly 30 is generally formed by laminating or winding polarity sheets and separators, the polarity sheets including a positive electrode sheet and a negative electrode sheet, the positive electrode tab drawn from the positive electrode sheet being electrically connected to the positive electrode column 20, and the negative electrode tab drawn from the negative electrode sheet being electrically connected to the negative electrode column 20.

[0099] The active material coated portion 31 is the portion of the electrode assembly 30 to which the active material is coated, and can assist in the desorption and insertion of metal ions during the charging and discharging process of the battery cell 100. The conductive portion 32 is a metal structure that electrically connects the active material coated portion 31 and the electrode column 20. Whether the electrode column is positive or negative, and whether it is not coated with active material, both are electrically connected to the active material coated portion 31 via the conductive portion 32, thereby enabling the charging and discharging of the battery cell 100.

[0100] In the embodiment of this application, the active material coated portion 31 is divided into a positive electrode active material coated portion and a negative electrode active material coated portion. The positive electrode active material coated portion includes the portion of the positive electrode current collector to which the positive electrode active material layer is coated, and the negative electrode active material coated portion includes the portion of the negative electrode current collector to which the negative electrode active material layer is coated. The conductive portion 32 is divided into a positive electrode conductive portion and a negative electrode conductive portion. The positive electrode conductive portion electrically connects the positive electrode active material coated portion and the positive electrode pole, and the negative electrode conductive portion electrically connects the negative electrode active material coated portion and the negative electrode pole.

[0101] For the sake of explanation, in the embodiments of this application, the positive electrode and negative electrode, such as the electrode column 20, conductive part 32, and active material coated part 31, will not be described separately. However, the descriptions of the electrode column 20, conductive part 32, and active material coated part 31, etc., and related descriptions in the embodiments of this application can all be applied to the structures of the positive electrode column, negative electrode column, positive electrode active material coated part, negative electrode active material coated part, positive electrode conductive part, and negative electrode conductive part.

[0102] In the embodiment of the present invention, the pole column 20 has a through hole 211 which penetrates the pole column 20 in the direction toward the cover plate 40 of the electrode assembly 30, forming a hollow structure inside the pole column 20. The hollow structure can reduce the weight of the pole column 20 to some extent and can further improve the gravimetric energy density of the battery cell 100 and the battery 1000.

[0103] At least a portion of the conductive portion 32 is provided within the through-hole 211; that is, a portion of the conductive portion 32 may be provided within the through-hole 211, or all of it may be provided within the through-hole 211. When a portion or all of the conductive portion 32 is housed within the through-hole 211, the portion of the conductive portion 32 located within the housing occupies space within the pole column 20, thereby reducing the space occupied by the conductive portion 32 within the housing 10. If the size of the housing 10 is fixed, some space can be saved within the housing 10 to accommodate a larger active material coated portion 31, improving the volumetric energy density of the battery cell 100. At the same time, the redundancy of the conductive portion 32 within the housing 10 can be reduced to some extent, reducing the probability of a short circuit between the conductive portion 32 and the active material coated portion 31, thereby lowering the probability of a short circuit in the battery cell 100, and improving the operational reliability and stability of the battery cell 100 and the battery 1000.

[0104] The battery cell 100 according to this application has through holes 211 in the pole posts 20, and at least a portion of the conductive portion 32 is provided within the through holes 211. This reduces the space occupied by the conductive portion 32 inside the housing 10, allowing a larger active material coated portion 31 to be accommodated within the housing cavity of the housing 10. This improves the volumetric energy density of the battery cell 100, reduces redundancy of the conductive portion 32 inside the housing 10, lowers the probability of a short circuit between the conductive portion 32 and the active material coated portion 31, reduces the probability of a short circuit in the battery cell 100, and improves the operational reliability and stability of the battery cell 100 and the battery 1000. Furthermore, by providing through holes 211 inside the pole posts 20, the weight of the pole posts 20 can be reduced, improving the gravimetric energy density of the battery cell 100 and the battery 1000.

[0105] In one example of the present invention, the cover plate 40 is welded to the conductive part 32.

[0106] The welding connection allows for the joining of two items of different sizes and materials, is easy to operate, requires no additional external materials, simplifies the connection process between the cover plate 40 and the conductive part 32, and reduces the production cost and overall weight of the battery cell 100. At the same time, the welding provides excellent connection strength and good airtightness, improving the connection strength and stability between the cover plate 40 and the conductive part 32, and improving the stability of the electrical connection between the conductive part 32 and the pole column 20.

[0107] In this embodiment, the cover plate 40 and the conductive part 32 are connected by welding, thereby improving the connection strength and stability between the cover plate 40 and the conductive part 32, further improving the stability of the electrical connection between the conductive part 32 and the pole 20, and at the same time reducing the complexity of the connection between the cover plate 40 and the conductive part 32, thereby reducing the production cost and overall weight of the battery cell 100.

[0108] According to one example of the present invention, as shown in Figure 4, the cover plate 40 has a first welding region 43 and a second welding region 44, the first welding region 43 is welded to the conductive portion 32 and the second welding region 44 is used to weld the electrical connection piece 50, and the first welding region 43 and the second welding region 44 are different regions of the cover plate 40.

[0109] Specifically, the electrical connection piece 50 is welded to the surface of the cover plate 40 on the side opposite to the electrode assembly 30 and is used to connect two adjacent battery cells 100 and to realize a series connection of the battery cells 100. The conductive part 32 has one end connected to the electrode assembly 30 and the other end welded to the surface of the cover plate 40 on the side facing the electrode assembly 30 and is used to communicate the inside and outside of the electrode assembly 30 and to realize electrical communication of the battery cells 100.

[0110] As can be understood, during welding, the action of the welding heat source causes a portion of the base material in the welded member to melt, forming a liquid metal with a certain geometric shape. This portion is called a molten pool, and after cooling, the molten pool forms a bead. The thickness at the bead position is slightly lower than that of the cover plate body 41. Furthermore, by providing the first welding area 43 and the second welding area 44 as different areas of the cover plate 40, the problem of reduced welding quality due to the connection of the two molten pools can be effectively prevented, improving the welding quality between the conductive part 32 and the electrical connection piece 50 and the cover plate 40, thereby improving the stability of the electrical connection of the battery cell 100.

[0111] In this embodiment, by providing a first welding area 43 and a second welding area 44, the welding positions of the conductive part 32 and the electrical connection piece 50 can be restricted, respectively, improving the ease and reliability of assembling the battery cell 100. Furthermore, by providing the first welding area 43 and the second welding area 44 as different areas of the cover plate 40, the problem of reduced welding quality due to the connection of the two molten pools can be effectively prevented, improving the welding quality between the conductive part 32 and the electrical connection piece 50 and the cover plate 40, thereby improving the stability of the electrical connection of the battery cell 100.

[0112] According to one example of the present invention, as shown in Figure 4, the first welding region 43 and the second welding region 44 are formed on both sides of a center line perpendicular to the length or width of the cover plate 40, respectively.

[0113] In other words, in some embodiments, the first welding area 43 and the second welding area 44 are formed on both sides of a center line perpendicular to the length direction of the cover plate 40, and in other embodiments, the first welding area 43 and the second welding area 44 are formed on both sides of a center line perpendicular to the width direction of the cover plate 40.

[0114] In this embodiment, the first welding area 43 and the second welding area 44 are provided on both sides of a center line perpendicular to the length or width direction of the cover plate 40, which makes it easier to further restrict the positions of the first welding area 43 and the second welding area 44, thereby improving the ease of assembly and reliability of the battery cell 100.

[0115] In one example of the present invention, the distance between the first welding area 43 and the second welding area 44 is less than or equal to two-thirds of the width of the cover plate 40.

[0116] For example, the distance between the first welding area 43 and the second welding area 44 may be one-third of the width of the cover plate 40, or it may be two-thirds of the width of the cover plate 40.

[0117] In this embodiment, by setting the distance between the first welding area 43 and the second welding area 44 to two-thirds or less of the width of the cover plate 40, the distance between the first welding area 43 and the second welding area 44 is not too large, which is advantageous in securing the welding area on the cover plate 40 for the first welding area 43 and the second welding area 44. This facilitates the connection between the conductive part 32 and the electrical connection piece 50 and the cover plate 40, guarantees the welding quality between the conductive part 32 and the electrical connection piece 50 and the cover plate 40, and thereby improves the stability of the electrical connection of the battery cell 100.

[0118] In one example of the present invention, the distance between the first welding area 43 and the second welding area 44 is one-third or more of the width of the cover plate 40.

[0119] In other words, the distance between the first welding area 43 and the second welding area 44 is at least one-third of the width of the cover plate 40 and at least two-thirds of the width of the cover plate 40.

[0120] For example, if the distance between the first welding area 43 and the second welding area 44 is d, and the width of the cover plate 40 is w, then the range of values ​​for d is [w / 3, 2w / 3].

[0121] In this embodiment, by setting the distance between the first welding area 43 and the second welding area 44 to be at least one-third of the width of the cover plate 40, the distance between the first welding area 43 and the second welding area 44 does not become too small, effectively preventing the problem of reduced welding quality due to the two molten pools connecting, improving the welding quality between the conductive part 32 and the electrical connection piece 50 and the cover plate 40, and improving the stability of the electrical connection of the battery cell 100.

[0122] According to one example of the present invention, the distance between the first welding region 43 and the second welding region 44 is 2 mm or more.

[0123] For example, the distance between the first welding area 43 and the second welding area 44 may be 2 mm, 2.5 mm, 3 mm, or more, and the size of the distance can be designed according to the actual situation.

[0124] In this embodiment, by setting the distance between the first welding area 43 and the second welding area 44 to 2 mm or more, the problem of reduced welding quality due to the two molten pools connecting can be effectively prevented, the welding quality between the conductive part 32 and the electrical connection piece 50 and the cover plate 40 can be improved, and the stability of the electrical connection of the battery cell 100 can be improved.

[0125] In one example of the present invention, a first welding region 43 and a conductive portion 32 are welded together to form a first molten pool 431, and a second welding region 44 and an electrical connecting piece 50 are welded together to form a second molten pool 441, with the first molten pool 431 and the second molten pool 441 spaced apart.

[0126] A molten pool refers to the portion of the base metal that melts into a pool-like shape due to the heat of the welding arc. The liquid metal portion with a specific geometric shape formed on the welded member during welding is called a molten pool, and after cooling, it forms a weld bead.

[0127] In this embodiment, by setting the first molten pool 431 and the second molten pool 432 to be spaced apart, the problem of the first molten pool 431 and the second molten pool 432 being connected can be effectively solved, the welding quality between the conductive part 32 and the electrical connection piece 50 and the cover plate 40 can be improved, and the stability of the electrical connection of the battery cell 100 can be improved.

[0128] In one example of this application, the ratio of the thickness of the cover plate 40 to the thickness of the first wall 11 is 1 to 4.

[0129] The housing 10 is primarily used to isolate the inside and outside of the battery cell 100, protect the battery cell 100, and ensure the safety of its use. For this reason, the structural strength of the housing 10 must be sufficient to resist the expansion force of the cell and prevent it from bursting. Furthermore, since the reaction force is applied to the electrode assembly 30 to fix the electrode assembly 30, the thickness of the first wall 11 must not only meet the required strength of the housing 10 but also meet the requirement for reducing the weight of the battery cell 100.

[0130] For example, the ratio of the thickness of the cover plate 40 to the thickness of the first wall 11 may be 1, 2, 3, or 4.

[0131] In this embodiment, by setting the ratio of the thickness of the cover plate 40 to the thickness of the first wall 11 to 1 to 4, the thickness of the cover plate 40 not only satisfies the welding requirements between the conductive part 32 and the electrical connection piece 50, but also prevents the thickness of the cover plate 40 from becoming too large, which helps to reduce the weight of the battery cell 100.

[0132] In one example of this application, the ratio of the thickness of the cover plate 40 to the thickness of the first wall 11 is 2 to 3.

[0133] For example, the ratio of the thickness of the cover plate 40 to the thickness of the first wall 11 may be 2, 2.5, or 3.

[0134] In this embodiment, by setting the ratio of the thickness of the cover plate 40 to the thickness of the first wall 11 to 2 to 3, the thickness of the cover plate 40 is further limited, preventing the cover plate 40 from becoming too thick, which helps to reduce the weight of the battery cell 100, while simultaneously preventing the cover plate 40 from becoming too thin, thus satisfying the welding requirements between the conductive part 32 and the electrical connection piece 50 and the structural strength requirements of the battery cell 100.

[0135] According to one example of this application, the thickness of the cover plate 40 is 1.5 mm or more and 5 mm or less.

[0136] The thickness of the cover plate 40 is related to the welding requirements between the conductive portion 32 and the electrical connection piece 50.

[0137] For example, the thickness a of the cover plate 40 may be 1.5 mm, 2 mm, 3 mm, 4 mm, or 5 mm.

[0138] In this embodiment, by setting the thickness of the cover plate 40 to 1.5 mm or more and 5 mm or less, the thickness of the cover plate 40 can satisfy the welding requirements between the conductive part 32 and the electrical connection piece 50, while also limiting the thickness of the cover plate 40 from becoming too large. This reduces the space occupied by the cover plate 40 in the through hole 211 and improves the space utilization rate of the battery cell 100.

[0139] According to one example of the present invention, as shown in Figure 5, the cover plate 40 includes a cover plate body 41 and a boss 42, the cover plate body 41 covers one end of the through hole 211, the boss 42 is provided on one side of the cover plate body 41 facing the electrode assembly 30 and extends into the through hole 211, and the conductive portion 32 is connected to the boss 42.

[0140] Specifically, the cover plate body 41 mainly covers the end of the through-hole 211 opposite to the electrode assembly 30 and is used to seal the battery cell 100, the boss 42 fits into the through-hole 211 and the size of the boss 42 can be made to fit the through-hole 211, the boss 42 can be used to further seal the side of the through-hole 211 opposite to the electrode assembly 30, further sealing the through-hole 211 and further reducing the risk of electrolyte leakage from the through-hole 211, thereby improving the reliability of the battery cell 100.

[0141] The electrical connection piece 50 is welded to the side of the cover plate body 41 opposite to the boss 42, and the conductive part 32 is welded to the side of the boss 42 opposite to the cover plate body 41. This further reduces the occurrence of situations where molten pools connect during the welding process, further improves the welding quality between the conductive part 32 and the electrical connection piece 50 and the cover plate 40, and thereby improves the stability of the electrical connection of the battery cell 100.

[0142] Furthermore, the cover plate body 41 and the boss 42 may be an integrated component or separate components. An integrated component reduces the production process of the cover plate 40, reduces the production steps of the cover plate 40, improves the production speed of the cover plate 40, and lowers the production cost of the cover plate 40. Separation of the components reduces the difficulty of production of the cover plate 40, reduces the mold cost of the cover plate 40, and lowers the production cost of the cover plate 40.

[0143] In this embodiment, by providing the cover plate body 41 and boss 42, the sealing effect between the cover plate 40 and the pole column 20 can be improved, further reducing the risk of electrolyte leakage from the through hole 211, improving the reliability of the battery cell 100, further reducing the occurrence of situations where the molten pool connects during the welding process, further improving the welding quality between the conductive part 32 and the electrical connection piece 50 and the cover plate 40, thereby improving the stability of the electrical connection of the battery cell 100.

[0144] In one example of the present invention, as shown in Figure 6, the height to which the boss 42 protrudes from the surface of one side of the cover plate body 41 is 1 mm to 5 mm.

[0145] For example, the height c at which the boss 42 protrudes from one side of the cover plate body 41 may be 1 mm, 2 mm, 3 mm, 4 mm, or 5 mm.

[0146] In this embodiment, by setting the height at which the boss 42 protrudes from one side surface of the cover plate 41 body to 1 mm to 5 mm, the thickness of the boss 42 does not become too large, which helps to reduce the internal space occupied by the through hole 211 by the cover plate 40, thereby improving the space utilization rate of the battery cell 100. The thickness of the boss 42 does not become too small, so that the thickness of the boss 42 meets the welding requirements of the conductive part 32, and improves the stability of the connection between the conductive part 32 and the boss 42.

[0147] In one example of this invention, the height to which the boss 42 protrudes from the surface of one side of the cover plate body 41 is 1.5 mm to 3 mm.

[0148] For example, the height to which the boss 42 protrudes from the surface of one side of the cover plate body 41 may be 1.5 mm, 2 mm, 2.5 mm, or 3 mm.

[0149] In this embodiment, by setting the height at which the boss 42 protrudes from one side surface of the cover plate body 41 to 1.5 mm to 3 mm, the thickness of the boss 42 can meet the welding requirements for the conductive part 32, and the space occupied by the cover plate 40 in the through hole 211 can be further reduced, thereby further improving the space utilization rate of the battery cell 100.

[0150] In one example of this invention, the boss 42 is fitted into a gap at one end of the through hole 211, and the fitting gap between the boss 42 and the through hole 211 is 0 to 0.1 mm.

[0151] Specifically, a gap fit refers to a fit that has a gap; that is, when a boss 42 is fitted into a through hole 211, a gap is formed between the outer wall of the boss 42 and the inner wall of the through hole 211. The minimum gap may be 0.

[0152] For example, the fitting gap between the boss 42 and the through hole 211 may be 0 mm, 0.01 mm, 0.02 mm, 0.04 mm, 0.06 mm, 0.08 mm, or 0.1 mm.

[0153] In this embodiment, the boss 42 is fitted into one end of the through hole 211, and the fitting gap between the boss 42 and the through hole 211 is set to 0 to 0.1 mm, which makes it easier to insert and remove the boss 42 from the through hole 211 and reduces the difficulty of assembling the cover plate 40 and the pole column 20.

[0154] According to one example of this application, the fitting gap between the boss 42 and the through hole 211 is 0.05 mm or less.

[0155] For example, the fitting gap between the boss 42 and the through hole 211 may be 0 mm, 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, or 0.05 mm.

[0156] In this embodiment, by setting the fitting gap between the boss 42 and the through hole 211 to 0.05 mm or less, the gap between the boss 42 and the inner wall of the through hole 211 can be further reduced, the sealing effect of the through hole 211 by the boss 42 can be further improved, the risk of electrolyte leakage from the cover plate 40 can be reduced, and the reliability of the battery cell 100 can be improved.

[0157] In one example of the present invention, the pole column 20 is a negative pole column, the cover plate body 41 and the boss 42 are separate, the cover plate body 41 and the boss 42 are made of different materials, the material of the boss 42 is the same as the material of the conductive part 32, and when the boss 42 is welded to the conductive part 32, the depth of the molten pool on the cover plate 40 is less than the thickness of the boss 42.

[0158] Specifically, the negative electrode pole is connected to the negative electrode active material coated portion via the negative electrode conductive portion, the material of the conductive portion 32 is the same as the material of the current collector of the active material coated portion 31, the boss 42 is welded to the conductive portion 32, and furthermore, the material of the boss 42 is the same as the material of the negative electrode current collector. The cover plate body 41 is welded to the electrical connection piece 50, and the material of the cover plate body 41 may be the same as the material of the electrical connection piece 50.

[0159] For example, in some specific embodiments, the negative electrode current collector is made of copper, meaning the conductive part 32 is made of copper, and the electrical connection piece 50 is generally made of aluminum. Therefore, the boss 42 can be made of copper, and the cover plate body 41 can be made of aluminum. Welding the same materials together reduces the difficulty of welding and improves the welding quality. Thus, by having the conductive part 32, the negative electrode current collector, and the boss 42 made of the same material, the difficulty of welding the conductive part 32 to the negative electrode current collector and the conductive part 32 to the boss 42 is reduced, and the welding quality between the conductive part 32 to the negative electrode current collector and the conductive part 32 to the boss 42 is improved. Similarly, by having the cover plate body 41 and the electrical connection piece 50 made of the same material, the difficulty of welding the electrical connection piece 50 to the cover plate body 41 is reduced, and the welding quality between the electrical connection piece 50 and the cover plate body 41 is improved.

[0160] In this embodiment, the pole column 20 is the negative pole column, the cover plate body 41 and the boss 42 are separate components, and the material of the boss 42 and the material of the conductive part 32 are made the same. This makes the material of the boss 42 and the material of the conductive part 32 compatible, thereby improving the welding quality between the boss 42 and the conductive part 32 and improving the connection stability between the boss 42 and the conductive part 32. Furthermore, when welding the boss 42 to the conductive part 32, the depth of the molten pool on the cover plate 40 is smaller than the thickness of the boss 42, and by controlling the welding position between the same material, the welding quality between the boss 42 and the conductive part 32 can be further improved, and the difficulty of welding the boss 42 and the conductive part 32 can be reduced.

[0161] In one example of the present invention, the pole column 20 is a positive pole column, the boss 42 and the cover plate body 41 are integrally molded, and when the cover plate 40 is welded to the conductive part 32, the depth of the molten pool on the boss 42 is greater than the thickness of the boss 42.

[0162] Specifically, the positive electrode column is connected to the positive electrode active material coated portion via the positive electrode conductive portion, the material of the conductive portion 32 is the same as the material of the current collector of the active material coated portion 31, and the material of the boss 42 may also be the same as the material of the positive electrode current collector.

[0163] For example, in some specific embodiments, the material of the positive electrode current collector is aluminum, meaning that the materials of both the conductive part 32 and the boss 42 can be selected to be aluminum, the material of the electrical connection piece 50 is generally aluminum, and furthermore, the material of the cover plate body 41 can also be selected to be aluminum, so that the materials of the cover plate body 41 and the boss 42 are the same.

[0164] In this embodiment, when the pole column 20 is a positive pole column, the boss 42 and the cover plate body 41 are integrally molded, so that the cover plate 40 satisfies the need for welding between the electrical connection piece 50 and the conductive part 32, reduces the production process of the cover plate 40, reduces the production steps of the cover plate 40, improves the production speed of the cover plate 40, and reduces the production cost of the cover plate 40.

[0165] In one example of this invention, the pole column 20 is welded to the cover plate 40.

[0166] The welding connection allows for the joining of two items of different sizes and materials, is easy to operate, requires no additional external materials, simplifies the connection process between the cover plate 40 and the pole column 20, and reduces the production cost and overall weight of the battery cell 100. At the same time, the welding provides excellent connection strength and good airtightness, improving the connection stability and sealing performance between the cover plate 40 and the pole column 20, thereby improving the sealing performance of the battery cell 100.

[0167] In this embodiment, by arranging the pole column 20 to be welded to the cover plate 40, the connection stability and sealing performance between the pole column 20 and the cover plate 40 can be improved, thereby improving the airtightness of the battery cell 100 and enhancing the reliability of the battery cell 100.

[0168] In one example of the present invention, as shown in Figures 7 to 11, the pole column 20 is hollow and annular, and a through hole 211 is defined on the inside.

[0169] Specifically, the pole column 20 is a hollow annular shape, meaning that a large hollow structure is formed inside the pole column 20, and the lateral cross-section of the pole column 20 forms an annular shape, which may include multiple types such as rectangular, circular, and rhombic shapes.

[0170] In this embodiment, by making the pole column 20 a hollow annular shape and defining a through hole 211 on its inside, the weight of the pole column 20 can be reduced to some extent, improving the gravimetric energy density of the battery cell 100 and the battery 1000. Furthermore, the large volume of the internal cavity of the hollow annular shape allows the conductive part 32 to extend very easily from the through hole 211, reducing the difficulty of welding the conductive part 32 to the cover plate 40, reducing the difficulty of assembling the battery cell 100, and improving the assembly speed of the battery cell 100.

[0171] According to one example of the present invention, as shown in Figures 7 to 11, the pole column 20 includes a pole column body 21, a first ring 22, and a second ring 23, wherein the pole column body 21 is annular and has a through hole 211 defined on its inside, the first ring 22 is connected to one end of the pole column body 21 facing the electrode assembly 30 and extends outward along the radial direction of the pole column body 21 and extends annularly along the circumferential direction of the pole column body 21, and the second ring 23 is connected to the other end of the pole column body 21 opposite to the electrode assembly 30 and extends outward along the radial direction of the pole column body 21 and extends annularly along the circumferential direction of the pole column body 21.

[0172] The pole column body 21 forms an annular shape, and for example, the cross-section of the pole column body 21 may form an annular structure such as a circular, rectangular, or rhombic shape.

[0173] One surface of the first ring 22 facing the electrode assembly 30 may be flush with the other surface of the pole post body 21 facing the electrode assembly 30, the shape of the first ring 22 can be adapted to the shape of the pole post body 21, the first ring 22 and the pole post body 21 may be provided as separate parts or integrally molded, the material of the first ring 22 may be the same as or different from the material of the pole post body 21, the axial thickness of the first ring 22 of the pole post body 21 can be reasonably set as needed for mounting and assembling the pole post 20, and optionally, one end of the first ring 22 facing the electrode assembly 30 of the pole post body 21 may be flanged outward along the radial direction of the pole post body 21.

[0174] One side of the second ring 23 facing the electrode assembly 30 may be flush with the surface of the pole post body 21 opposite to the electrode assembly 30, the shape of the second ring 23 can be adapted to the shape of the pole post body 21, the second ring 23 and the pole post body 21 may be provided as separate parts or integrally molded, the material of the second ring 23 may be the same as or different from the material of the pole post body 21, the axial thickness of the second ring 23 in the pole post body 21 can be reasonably set as needed for mounting and assembling the pole post 20, and optionally, the end of the second ring 23 opposite to the electrode assembly 30 of the pole post body 21 may be flanged outward along the radial direction of the pole post body 21.

[0175] In this embodiment, by providing a first ring 22 and a second ring 23 at both ends of the pole post body 21, the first ring 22 and the second ring 23 can improve the structural strength of the pole post body 21 to some extent, thereby improving the overall structural strength of the pole post 20, making the connection and fixing of the pole post 20 to the tab more stable and reliable, and allowing the pole post 20 to participate more effectively in the task of transmitting electrical energy from the battery cell 100. The first ring 22 and the second ring 23 can engage with the pole post body 21 to form a locking groove structure, thereby facilitating the attachment and fixing of the pole post 20 in the battery cell 100, and the structure of the first ring 22 and the second ring 23 is simple and easy to use.

[0176] In one example of the present invention, as shown in Figure 11, a groove 212 is formed on the surface of the pole column 20 opposite to the electrode assembly 30, a through hole 211 is formed inside the groove 212 and penetrates the bottom wall of the groove 212, and the cover plate 40 is provided inside the groove 212.

[0177] Specifically, the shape of the groove 212 can be adapted to the shape and structure of the cover plate 40, and the depth of the groove 212 can be adapted to the thickness of the cover plate 40. The axis of the groove 212 may be on the same line as the axis of the through hole 211, and when the cover plate 40 and the pole column 20 are assembled, one side of the cover plate 40 facing the electrode assembly 30 abuts against the bottom of the groove 212, and the periphery of the cover plate 40 abuts against the groove wall of the groove 212.

[0178] The groove 212 communicates with the through hole 211, the through hole 211 penetrates the bottom wall of the groove 212, the diameter of the through hole 211 is smaller than the diameter of the groove 212, the side of the cover plate 40 facing the electrode assembly 30 abuts against the bottom wall of the groove 212, covering the through hole 211 and used to seal the battery cell 100, effectively preventing electrolyte leakage from the through hole 211, thereby improving the reliability of the battery cell 100.

[0179] In this embodiment, a groove 212 is formed on the surface of the pole column 20 opposite to the electrode assembly 30, which makes it easier to position the pole column 20 when fixing the cover plate 40 and ensures stable and reliable connection and fixing.

[0180] In one example of the present invention, as shown in Figure 11, in the direction from the electrode assembly 30 toward the cover plate 40, the side wall of the groove 212 extends inclined outward along the radial direction of the through hole 211.

[0181] Specifically, the side walls of the groove 212 extend outward inclined along the radial direction of the connection hole, the inclination angle of the side walls can be reasonably set as needed for mounting and fixing the cover plate 40, the direction of extension of the side walls of the groove 212 can be matched to the direction of extension of the periphery of the cover plate 40, and the side walls of the groove 212 may abut against the periphery of the cover plate 40.

[0182] For example, as shown in Figure 11, the longitudinal cross-section of the groove 212 may be formed as a trapezoid with a wider top and a narrower bottom, and the side walls of the groove 212 are formed as inclined surfaces that slope outward. This allows the cover plate 40 to act as a guide when the cover plate 40 and pole column 20 are assembled, allowing the cover plate 40 to be smoothly inserted into the groove 212. At the same time, the inclined surface has a larger area than a vertical plane, which increases the contact area between the cover plate 40 and the pole column 20, improving the welding width during welding and improving the sealing effect between the cover plate 40 and the pole column 20.

[0183] In this embodiment, the side walls of the groove 212 are provided to incline outward along the radial direction of the through hole 211, thereby providing a certain guiding effect when assembling the cover plate 40 and the pole column 20, allowing the cover plate 40 to be easily fixed in the groove 212, resulting in a simple structure and ease of assembly. At the same time, when the cover plate 40 is welded to the pole column 20, the periphery of the cover plate 40 and the inclined side walls of the groove 212 can further widen the welding width during welding, thereby resulting in high welding quality between the cover plate 40 and the pole column 20, improving the welded sealing effect between the cover plate 40 and the pole column 20, and improving the sealing performance of the battery cell 100.

[0184] In one example of the present invention, the surface of the cover plate 40 opposite to the electrode assembly 30 is flush with the end face of the pole column 20 opposite to the electrode assembly 30.

[0185] As can be understood, after the cover plate 40 and the pole column 20 are assembled, the cover plate 40 can form a continuous plane with the pole column 20 on the side opposite to the electrode assembly 30 of the pole column 20. Specifically, the surface of the second ring 23 on the side opposite to the electrode assembly 30 may be flush with the surface of the pole column 20 on the side opposite to the electrode assembly 30 and the surface of the cover plate 40 on the side opposite to the electrode assembly 30.

[0186] For example, as shown in Figures 4 and 5, the upper surface of the cover plate 40 is flush with the upper surface of the second ring 23 of the pole column 20.

[0187] In this embodiment, by arranging the cover plate 40 so that the surface on the side opposite to the electrode assembly 30 is flush with the end face of the pole column 20 opposite to the electrode assembly 30, the cover plate 40 and the pole column 20 can be combined to form a continuous plane, thereby reducing the space occupied by the cover plate 40 to some extent and increasing the electrical connection surface of the pole column 20 of the battery cell 100, thereby increasing the energy density of the battery cell 100 to some extent. The battery cell 100 can also be easily electrically connected to an electrical connection member via the end of the pole column 20 opposite to the electrode assembly 30, and at the same time, the aesthetic appearance of the battery cell 100 can be improved.

[0188] According to one example of the present invention, the active material coated portion 31 includes a current collector and an active material layer provided on the current collector, the conductive portion 32 includes a tab portion 321 electrically connected to the current collector, the tab portion 321 includes a plurality of tab pieces, the tab pieces closer to the current collector are bundled together to form a first convergence portion 3211, the tab pieces further from the current collector are bundled and connected together to form a second convergence portion 3212, the first convergence portion 3211 connects the second convergence portion 3212 and the active material coated portion 31, and at least a portion of the second convergence portion 3212 is housed in a through hole 211.

[0189] Specifically, a current collector is a component that supports an active material and collects the current generated by the active material of a battery for output. A current collector includes a positive electrode current collector and a negative electrode current collector, and the materials of the positive electrode current collector and the negative electrode current collector are different. For example, in a lithium-ion battery, the positive electrode current collector may be made of aluminum, and the negative electrode current collector may be made of copper.

[0190] The active material layer is mainly applied to the current collector, and the active material layer includes a positive electrode active material layer and a negative electrode active material layer. The positive electrode active material layer and the negative electrode active material have different functions, and the materials of the positive electrode active material layer and the negative electrode active material are also different. For example, in a lithium-ion battery, the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, and the negative electrode active material may be carbon or silicon, etc.

[0191] The tab portion 321 is a contact point when the battery cell 100 is charging and discharging, and the tab portion 321 includes multiple tab pieces, for example, the number of tab pieces may be two, three, four, or more. The tab pieces are electrically connected to the current collector, but the structure is not coated with active material, and may be formed by directly die-cutting the current collector.

[0192] In the above technical solution, when the first convergence portion 3211 is formed, the multiple tab pieces are bundled together (i.e., brought together in a direction that brings them closer to each other) but are not connected. However, when the second convergence portion 3212 is formed, the multiple tab pieces are not only bundled together but also connected to an integrated structure. For example, the multiple tab pieces can be connected to an integrated sheet-like structure by welding (e.g., ultrasonic welding) to form the second convergence portion 3212. Alternatively, the multiple tab pieces may be bundled and connected by methods such as bonding with a conductive adhesive to form the second convergence portion 3212, but this will not be explained here.

[0193] In the embodiment of this application, the tab pieces are divided into positive electrode tab pieces and negative electrode tab pieces. The positive electrode tab pieces, which need to be combined into one, are laminated integrally and subjected to ultrasonic pre-welding to form a second convergence portion 3212 of the positive electrode, thereby reducing the gap between layers and thereby forming a sheet structure in which the bulky multiple positive electrode tab pieces have a certain degree of rigidity. Similarly, the negative electrode tab pieces, which need to be combined into one, are laminated integrally and subjected to ultrasonic pre-welding to form a second convergence portion 3212 of the negative electrode, thereby reducing the gap between layers and thereby forming a sheet structure in which the bulky multiple negative electrode tab pieces have a certain degree of rigidity.

[0194] In the above technical solution, the statement that "the positions of the multiple tab pieces close to the current collector are bundled together to form a first convergence portion 3211, and the positions of the multiple tab pieces far from the current collector are bundled and connected to form a second convergence portion 3212" is explained as follows. Along the extending direction of the tab pieces, the first convergence portion 3211 and the second convergence portion 3212 are provided in order along the direction away from the current collector, but the specific positions of the first convergence portion 3211 and the second convergence portion 3212 are not limited; that is, it is not required how close the first convergence portion 3211 is to the current collector, nor how far the second convergence portion 3212 is from the current collector. In some selectable examples, the current collector and the tab pieces may be an integral component; for example, in the case of a positive electrode sheet, it may be an integrally molded aluminum foil, and in the case of a negative electrode sheet, it may be an integrally molded copper foil, etc.

[0195] In this embodiment, by arranging the components so that multiple tab pieces are bundled and connected to form a second convergence portion 3212, the size and thickness of the second convergence portion 3212 can be reduced, thereby allowing the tab portion 321 to easily enter the through hole 211 and connect to the cover plate 40, improving the ease of connection between the conductive portion 32 and the cover plate 40. At the same time, the branching of the multiple tab pieces effectively reduces the risk of reverse insertion of tab pieces and short-circuiting with the active material coated portion 31 below the tab portion 321, thereby improving the reliability of the battery cell 100. Furthermore, by arranging the components so that at least a portion of the second convergence portion 3212 is housed within the through hole 211, the space of the pole column 20 can be fully utilized, improving the volumetric energy density of the battery cell 100.

[0196] In one example of the present invention, as shown in Figure 14, the conductive portion 32 is fixedly connected to the cover plate 40 via the second convergence portion 3212.

[0197] In this embodiment, by arranging the conductive portion 32 to be fixedly connected to the cover plate 40 via the second convergence portion 3212, the structure of the battery cell 100 can be simplified, the use of parts can be reduced, the assembly flow can be simplified, and the assembly efficiency can be improved.

[0198] According to one example of the present invention, at least a portion of the first convergence portion 3211 is housed within the through hole 211.

[0199] In other words, at least a portion of the first convergence portion 3211 and at least a portion of the second convergence portion 3212 are both housed within the through hole 211.

[0200] In this embodiment, by arranging the first convergence portion 3211 so that at least a part of it is housed within the through-hole 211, the space within the pole column 20 can be utilized more fully, the space occupied by the tab portion 321 within the housing 10 can be further reduced, a larger active material coated portion 31 can be accommodated, improving the volumetric energy density of the battery cell 100, and the redundancy of the tab portion 321 within the housing 10 can be effectively reduced, further lowering the probability of a short circuit between the tab portion 321 and the active material coated portion 31.

[0201] According to one example of the present invention, the active material coated portion 31 includes a current collector and an active material layer provided on the current collector, the conductive portion 32 includes a tab portion 321 electrically connected to the current collector, the tab portion 321 includes a plurality of tab pieces, the tab pieces closer to the current collector are bundled together to form a first convergence portion 3211, the tab pieces further away from the current collector are bundled and connected to form a second convergence portion 3212, the first convergence portion 3211 connects the second convergence portion 3212 and the active material coated portion 31, the conductive portion 32 further includes a connecting piece, the connecting piece is connected to the second convergence portion 3212, the conductive portion 32 is electrically connected to the cover plate 40 via the connecting piece, and at least a portion of the connecting piece is housed in a through hole 211.

[0202] Specifically, the active material coated portion 31 can achieve electrical connection with the cover plate 40 via the first convergence portion 3211, the second convergence portion 3212, and the connecting piece in sequence. The electrical connection between the conductive portion 32 and the cover plate 40 is located on the connecting piece, and the electrical connection can be achieved, for example, by welding (e.g., laser welding) between the connecting piece and the cover plate 40. Furthermore, the connecting piece and the tab piece are two independent components and are connected by a method such as welding (e.g., ultrasonic welding).

[0203] To be understood, in this example, at least a portion of the second convergence portion 3212 may also be housed within the through-hole 211, and at least a portion of the first convergence portion 3211 may also be housed within the through-hole 211, or it may not be housed within the through-hole 211.

[0204] In this embodiment, by providing a connecting piece, at least a portion of the second convergence portion 3212 and at least a portion of the connecting piece can be housed within the through hole 211, allowing for more efficient use of the space within the pole column 20, further reducing the space occupied by the conductive portion 32 within the housing 10, and improving the volumetric energy density of the battery cell 100. At the same time, the portion of the connecting piece that avoids the second convergence portion 3212 can be welded to the pole column 20, thereby making the weld between the connecting piece and the pole column 20 more robust, reducing the risk of welding cracks, and further improving the reliability and stability of the battery cell 100. Simultaneously, by electrically connecting the pole column 20 and the tab piece via the connecting piece, the structure of the tab piece can be simplified.

[0205] In one example of the present invention, at least a portion of the second convergence portion 3212 is located within the through hole 211, or the entire second convergence portion 3212 is located within the through hole 211, and at least a portion of the first convergence portion 3211 is located within the through hole 211.

[0206] To be understood, in some specific embodiments of the present application, the second convergence portion 3212 may be located in part within the through hole 211 or entirely within the through hole 211, and the first convergence portion 3211 may be located in part within the through hole 211 or not within the through hole 211.

[0207] In another specific embodiment of the present application, the second convergence portion 3212 is entirely located within the through hole 211, and at least a portion of the first convergence portion 3211 is located within the through hole 211. At least a portion of the first convergence portion 3211 is located within the through hole 211, that is, the first convergence portion 3211 may be partially located within the through hole 211, or it may be entirely located within the through hole 211.

[0208] In this embodiment, by arranging the second convergence portion 3212 so that at least a portion of it is located within the through-hole 211, the space within the pole column 20 can be fully utilized, the space occupied by the tab portion 321 within the housing 10 can be further reduced, and the volumetric energy density of the battery cell 100 can be improved. By arranging the second convergence portion 3212 so that it is entirely located within the through-hole 211 and at least a portion of the first convergence portion 3211 is located within the through-hole 211, the space within the pole column 20 can be fully utilized, the space occupied by the tab portion 321 within the housing 10 can be significantly reduced, and the volumetric energy density of the battery cell 100 can be significantly improved. At the same time, the redundancy of the tab portion 321 within the housing 10 can be further reduced, and the probability of a short circuit between the tab portion 321 and the active material coated portion 31 can be further reduced.

[0209] In one example of the present invention, the second convergence portion 3212 extends along the surface of the cover plate 40, and in the direction from the electrode assembly 30 toward the cover plate 40, one end of the first convergence portion 3211 is connected to the active material coating portion 31, and the other end of the first convergence portion 3211 extends inclined toward the peripheral wall of the through hole 211 and extends to one end of the second convergence portion 3212 and is connected thereto.

[0210] Specifically, in the direction toward the cover plate 40 of the electrode assembly 30, the first convergence portion 3211 and the second convergence portion 3212 are arranged in order, and the active material coating portion, the first convergence portion 3211, and the second convergence portion 3212 are connected in order. When the cover plate 40 and the pole column 20 are fixedly connected, the second convergence portion 3212 extends along the surface of the cover plate 40, and the end of the first convergence portion 3211 opposite to the active material coating portion 31 extends inclined toward the peripheral wall of the through hole 211, that is, the tab portion 321 is formed in a "Z" shape within the through hole 211, thereby reducing the space occupied by the tab portion 321.

[0211] In this embodiment, the second convergence portion 3212 extends along the surface of the cover plate 40, and in the direction from the electrode assembly 30 toward the cover plate 40, one end of the first convergence portion 3211 is connected to the active material coating portion 31, and the other end of the first convergence portion 3211 extends inclined toward the peripheral wall of the through hole 211 and extends to one end of the second convergence portion 3212 and connects to it. This increases the length of the first convergence portion 3211 that can be accommodated inside the through hole 211, effectively reduces the space occupied by the tab inside the battery cell 100, allows for the accommodation of a larger active material coating portion 31 and improves the volumetric energy density of the battery cell 100, effectively reduces the redundancy of the tab portion 321 within the housing 10, and further reduces the probability of a short circuit between the tab portion 321 and the active material coating portion 31, thereby improving the stability of the battery cell 100.

[0212] A method for manufacturing a battery cell 100 according to a second aspect of the present application, the manufacturing method comprising: passing one end of a conductive portion 32 through a through hole 211 of a pole column 20 and extending it from the other side of the pole column 20; welding one end of the conductive portion 32 to a cover plate 40 on the other side of the pole column 20; placing the cover plate 40 over one end of the through hole 211 to house the conductive portion 32 inside the through hole 211; and fixing the cover plate 40 to the pole column 20.

[0213] One end of the conductive portion 32 refers to the end opposite to the active material coated portion 31 and may be understood as one end of the second convergence portion 3212 or connecting piece; the other side of the pole column 20 refers to the side of the pole column 20 opposite to the active material coated portion 31 of the second ring 23; and one end of the through hole 211 refers to the end of the through hole 211 opposite to the active material coated portion 31.

[0214] In the embodiment of the present invention, there may be various methods for passing one end of the conductive portion 32 through the through hole 211 of the electrode column 20. For example, the electrode assembly 30 may be placed on its side, and then the electrode assembly 30 may be pushed using an air cylinder to move it toward the electrode column 20, passing the conductive portion 32 through the through hole 211 and extending into the interior of the battery cell 100 from the side opposite to the active material coated portion 31 of the electrode column 20. Alternatively, the housing 10 may be pushed toward the electrode assembly 30, passing the conductive portion 32 through the through hole 211 and extending into the interior of the battery cell 100 from the side opposite to the active material coated portion 31 of the electrode column 20.

[0215] When manufacturing the battery cell 100, the end of the conductive part 32 opposite to the active material coated part 31 is pushed and moved toward the pole column 20, and the other end of the conductive part 32 opposite to the active material coated part 31 is extended into the inside of the battery cell 100 from the side of the pole column 20 opposite to the active material coated part 31. The extended portion of the conductive part 32 and the cover plate 40 are welded together on the outside of the battery cell 100, thereby reducing damage to the battery cell 100 caused by slag falling into the inside of the battery cell 100 during the welding process. After that, the cover plate 40 and the pole column 20 are assembled, the cover plate 40 is placed over the end of the through hole 211 opposite to the active material coated part 31, the tab is bent and housed in the through hole 211, and then the cover plate 40 and the pole column 20 are welded together to seal the battery cell 100.

[0216] According to the manufacturing method of the battery cell 100 of the present invention, the cover plate 40 and the conductive part 32 can be welded together on the outside of the battery cell 100. This reduces damage to the battery cell 100 caused by slag falling into the inside of the battery cell 100 during the welding process, thereby improving the reliability of the battery cell 100. At the same time, by housing the conductive part 32 within the through hole 211, the space occupied by the conductive part 32 inside the housing 10 is reduced, allowing a larger volume of the active material coated part 31 to be housed in the housing 10, thereby improving the energy density of the battery cell 100. Furthermore, the redundancy of the conductive part 32 is reduced, the probability of a short circuit between the conductive part 32 and the active material coated part 31 is decreased, and the stability of the battery cell 100 can be improved.

[0217] In some specific embodiments of the present invention, the manufacturing method further includes pre-welding multiple tab pieces of the tab portion 321 together before one end of the tab portion 321 extends from the other side of the pole column 20 through the through hole 211 of the pole column 20.

[0218] Multiple tab pieces can be stacked to form a tab, and these tab pieces can be joined together by ultrasonic pre-welding to form one end of the tab.

[0219] In this embodiment, by pre-welding multiple tab pieces of the tab portion 321 to form a single unit, the gap between the tab pieces is reduced, making one end of the tab portion 321 more compact, thereby facilitating subsequent work by inserting the tab portion 321 into the through hole 211.

[0220] According to one example of the present invention, welding one end of the conductive portion 32 to the cover plate 40 on the other side of the pole column 20 includes pressing the other end of the conductive portion 32 to the surface of one side of the cover plate 40 and laser welding the other end of the conductive portion 32 to the cover plate 40.

[0221] To make it clear, after the end of the conductive portion 32 opposite to the active material coated portion 31 extends into the through hole 211, the extended end of the conductive portion 32 is first pressed against the boss 42 of the cover plate 40 to secure a welding gap, and then the conductive portion 32 is laser-welded to the cover plate 40 using a laser.

[0222] Laser welding is a highly efficient and precise welding method that utilizes a high-energy-density laser beam as a heat source. It enables non-contact welding and has advantages such as high precision, high speed, and minimal deformation. By employing laser welding for the conductive part 32 and the cover plate 40, the connection speed between the conductive part 32 and the cover plate 40 can be improved, and the welding quality between the conductive part 32 and the cover plate 40 can be enhanced.

[0223] In this embodiment, the other end of the conductive part 32 is pressed against the surface of one side of the cover plate 40 to secure a welding gap and enable laser welding, thereby improving welding quality. By welding the conductive part 32 and the cover plate 40 using a laser, the connection speed between the conductive part 32 and the cover plate 40 can be improved, and the welding quality between the conductive part 32 and the cover plate 40 can be improved.

[0224] In some specific embodiments of the present invention, the fixed connection of the cover plate 40 to the pole column 20 includes welding the cover plate 40 to the pole column 20.

[0225] To make it clear, after laser welding the conductive part 32 and the cover plate 40, the cover plate 40 and the pole 20 are assembled, the cover plate 40 is fitted into the groove 212 on the side of the pole 20 opposite to the electrode assembly 30, the pole 20 is welded to the cover plate 40, and is used to cover the end of the through hole 211 opposite to the active material coated part 31, finally completing the assembly of the battery cell 100.

[0226] In this embodiment, by arranging the cover plate 40 and the pole column 20 to be welded together, the connection stability between the cover plate 40 and the pole column 20 can be improved, the sealing performance of the battery cell 100 can be improved, and the reliability of the battery cell 100 can be improved.

[0227] A battery 1000 according to an embodiment of the third aspect of the present application, comprising a battery cell 100 according to an embodiment of the first aspect of the present application.

[0228] In some specific embodiments of the present invention, as shown in Figure 2, for example, the battery 1000 further includes a main housing 201 and an end cover 202, the main housing 201 having a cavity with an open top, a plurality of battery cells 100 provided within the cavity, and the end cover 202 covering the top of the main housing 201 by fastening members.

[0229] Selectively, multiple battery cells 100 may be stacked along the thickness direction of the battery cells 100 and arranged within the cavity.

[0230] Selectively, the main housing 201 is formed in the shape of a rectangular box, a cavity is defined inside the main housing 201, the top of the cavity is open, and the main housing 201 is provided with a plurality of first fixing holes, the end cover 202 is formed in the shape of a flat plate that is installed horizontally, and the end cover 202 is provided with a plurality of second fixing holes that penetrate the end cover 202 along the vertical direction, the plurality of first fixing holes correspond one-to-one with the plurality of second fixing holes and are opposed to each other vertically, and the battery 1000 further includes a plurality of fastening members, the plurality of fastening members pass through the first fixing holes and the second fixing holes and fasten the end cover 202 to the upper side of the main housing 201.

[0231] Selectively, the end cover 202 may be made of carbon steel, aluminum, or composite material.

[0232] In this embodiment, by providing the housing 200 as a separate main housing 201 and end cover 202, the battery cell 100 can be easily inserted into the housing 200. The main housing 201 and the end cover 202 are connected by fastening members, enabling a removable connection, facilitating maintenance and replacement, and ensuring connection strength between the main housing 201 and the end cover 202, thereby guaranteeing the overall structural strength of the battery 1000.

[0233] In some specific embodiments of the present invention, a first adhesive layer is provided on the bottom wall of the cavity, and the bottoms of the multiple battery cells 100 are connected to the bottom wall of the main housing 201 via the first adhesive layer, and / or a second adhesive layer is provided on the end cover 202, and the tops of the multiple battery cells 100 are connected to the end cover 202 via the second adhesive layer.

[0234] The battery 1000 may include only the first adhesive layer, only the second adhesive layer, or both the first and second adhesive layers. The first adhesive layer is used to bond and connect the battery cell 100 to the bottom wall of the main housing 201, and the second adhesive layer is used to bond and connect the battery cell 100 to the end cover 202. This securely fixes multiple battery cells 100 within the housing 200, improving the reliability and stability of the connection between the battery cells 100 and the housing 200, and effectively preventing the battery cells 100 from shaking within the housing 200.

[0235] In this embodiment, a first adhesive layer and a second adhesive layer are provided, and the bottom of the battery cell 100 is bonded and fixed to the bottom wall of the main housing 201 via the first adhesive layer, and the top of the battery cell 100 is bonded and fixed to the end cover 202 via the second adhesive layer, thereby improving the overall strength of the battery 1000 and ensuring the connection stability of the battery cell 100.

[0236] According to the battery 1000 of the embodiment of the present application, the overall performance of the battery 1000 is improved by providing the battery cell 100 of the embodiment of the first embodiment described above.

[0237] An electrical device according to an embodiment of the fourth aspect of the present application, comprising a battery 1000 according to an embodiment of the third aspect of the present application for supplying electrical energy.

[0238] The electrical device may be any of the aforementioned devices or systems that utilize the battery 1000.

[0239] According to the electrical device of the embodiment of the present application, the overall performance of the electrical device is improved by providing the battery 1000 of the third embodiment described above.

[0240] A specific embodiment of the present invention, the battery cell 100, will be described below with reference to Figures 3 to 14.

[0241] Referring to Figure 3, the battery cell 100 includes a housing 10, poles 20, a cover plate 40, and an electrode assembly 30. The housing 10 includes a first wall 11 and a housing cavity, the poles 20 are provided in the first wall 11 and have through holes 211, the cover plate 40 is provided on the side of the poles 20 opposite to the electrode assembly 30 and welded to the poles 20, covering one end of the through holes 211 opposite to the electrode assembly 30, the electrode assembly 30 is provided in the housing cavity and includes an active material coated portion 31 and a conductive portion 32, and is the central component of the battery cell 100.

[0242] Specifically, the active material coated portion 31 is the polarity sheet of the electrode assembly 30, and the conductive portion 32 is the tab of the electrode assembly 30. The polarity sheet has a positive electrode sheet and a negative electrode sheet, and the polarity sheet includes a current collector and an active material layer provided on the current collector, and the tab includes a plurality of tab pieces, the positions of the plurality of tab pieces close to the current collector are bundled together to form a first convergence portion 3211, and the positions of the plurality of tab pieces far from the current collector are bundled and connected to form a second convergence portion 3212, the first convergence portion 3211 connects the second convergence portion 3212 and the active material coated portion 31, at least a part of the second convergence portion 3212 is housed in a through hole 211 and is welded to the cover plate 40.

[0243] The second convergence portion 3212 extends along the surface of the cover plate 40, and in the direction from the electrode assembly 30 toward the cover plate 40, one end of the first convergence portion 3211 is connected to the active material coating portion 31, and the other end of the first convergence portion 3211 extends inclined toward the peripheral wall of the through hole 211 and extends to one end of the second convergence portion 3212 and connects to it, forming a "Z" shape.

[0244] The cover plate 40 includes a cover plate body 41 and a boss 42. The cover plate body 41 covers one end of the through hole 211, and the boss 42 is provided on one side of the cover plate body 41 facing the electrode assembly 30 and fits into the through hole 211. The boss 42 is fitted into the through hole 211, and the conductive portion 32 is connected to one side of the boss 42 facing the electrode assembly 30. The electrical connection piece 50 is connected to the side of the cover plate body 41 opposite to the electrode assembly 30.

[0245] The cover plate 40 further includes a first welding area 43 and a second welding area 44, the first welding area 43 and the second welding area 44 being formed on either side of a center line perpendicular to the length of the cover plate 40, the first welding area 43 being connected to a conductive part 32 and the second welding area 44 being connected to an electrical connection piece 50, the first welding area 43 and the second welding area 44 being indirectly arranged, and the distance between the first welding area 43 and the second welding area 44 being 2 mm or more.

[0246] Furthermore, the thickness of the cover plate 40 is 1.5 mm or more and 5 mm or less, the height at which the boss 42 protrudes from the surface of one side of the cover plate body 41 is 1.5 mm to 3 mm, and the fitting gap between the boss 42 and the through hole 211 is 0.05 mm or less.

[0247] The pole column 20 includes a pole column body 21, a first ring 22, and a second ring 23. The pole column body 21 is annular and has a through hole 211 defined on its inside. The first ring 22 and the pole column body 21 are integrally molded and located within the housing cavity. The first ring 22 is circumferentially positioned on the outer surface of the pole column body 21. One side of the first ring 22 facing the electrode assembly 30 is flush with the surface of the pole column body 21 facing the electrode assembly 30, while the other side abuts against the inner wall of the housing 10. The second ring 23 is integrally molded with the pole column body 21 and located outside the housing 10. The second ring 23 is circumferentially positioned on the outer surface of the pole column body 21. The side of the second ring 23 opposite to the electrode assembly 30 is flush with the surface of the pole column body 21 opposite to the electrode assembly 30, while the other side abuts against the housing 10.

[0248] A groove 212 is formed on the surface of the pole column 20 opposite to the electrode assembly 30. In the direction from the electrode assembly 30 toward the cover plate 40, the side wall of the groove 212 extends outward inclined along the radial direction of the through hole 211. The through hole 211 is formed inside the groove 212 and penetrates the bottom wall of the groove 212. The cover plate 40 is fitted inside the groove 212, covering the through hole 211, and the outer surface of the cover plate 40 is flush with the outer surface of the pole column 20.

[0249] The battery cell 100 according to this application has through holes 211 in the pole posts 20, and at least a portion of the conductive portion 32 is provided within the through holes 211. This reduces the space occupied by the conductive portion 32 inside the housing 10, allowing a larger active material coated portion 31 to be accommodated within the housing cavity of the housing 10. This improves the volumetric energy density of the battery cell 100, reduces redundancy of the conductive portion 32 inside the housing 10, lowers the probability of a short circuit between the conductive portion 32 and the active material coated portion 31, reduces the probability of a short circuit in the battery cell 100, and improves the operational reliability and stability of the battery cell 100 and the battery 1000. Furthermore, by providing through holes 211 inside the pole posts 20, the weight of the pole posts 20 can be reduced, improving the gravimetric energy density of the battery cell 100 and the battery 1000.

[0250] Finally, it should be noted that the above embodiments are merely for illustrating, and not limiting, the technical solutions of the present application. While the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that it is still possible to modify the technical solutions described in the above embodiments, or to substitute some or all of their technical features, and such modifications or substitutions do not cause the substance of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included within the scope of the claims and specification of the present application. In particular, the technical features mentioned in each embodiment can all be combined in any way, provided there is no structural inconsistency. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions included in the claims. [Explanation of Symbols]

[0251] 1 vehicle 1000 batteries 100 battery cells 10 Housing 11 1st wall 20 poles 21. Main pole 211 Through hole 212 groove 22 First Ring 23. Second Ring 30 Electrode Assembly 31 Active material coated section 32 Conductive part 321 Tab section 3211 First convergence section 3212 Second convergence section 40 Cover Plate 41 Cover plate body 42 Boss 43. First welding area 431 First Melting Pool 44. Second welding area 441 Second Melting Pool 50 electrical connection pieces 200 cabinets 201 Main enclosure 202 End Cover 2000 Controller 3000 motor

Claims

1. Housing including the first wall, A pole column provided in the first wall and having a through hole, A cover plate provided on one side of the pole column and covering one end corresponding to the through hole, The electrode assembly includes an active material coated portion and a conductive portion connected to the active material coated portion, A battery cell in which the active material coating portion is provided within the housing, and at least a portion of the conductive portion is provided within the through hole and connected to the cover plate.

2. The battery cell according to claim 1, wherein the cover plate is welded to the conductive portion.

3. The battery cell according to any one of claims 1 to 2, wherein the cover plate has a first welding region and a second welding region, the first welding region is welded to the conductive portion, and the second welding region is used to weld an electrical connection piece, and the first welding region and the second welding region are different regions of the cover plate.

4. The battery cell according to claim 3, wherein the first welding region and the second welding region are formed on both sides of a center line perpendicular to the length or width direction of the cover plate, respectively.

5. The battery cell according to claim 4, wherein the distance between the first welding area and the second welding area is two-thirds or less of the width of the cover plate, and / or the distance between the first welding area and the second welding area is one-third or more of the width of the cover plate.

6. The battery cell according to any one of claims 3 to 5, wherein the distance between the first welding area and the second welding area is 2 mm or more.

7. The battery cell according to any one of claims 3 to 6, wherein the first welding region and the conductive portion are welded together to form a first molten pool, the second welding region and the electrical connection piece are welded together to form a second molten pool, and the first molten pool and the second molten pool are spaced apart.

8. The battery cell according to claim 1, wherein the ratio of the thickness of the cover plate to the thickness of the first wall is 1 to 4, selectively, the ratio of the thickness of the cover plate to the thickness of the first wall is 2 to 3, and selectively, the thickness of the cover plate is 1.5 mm or more and 5 mm or less.

9. The battery cell according to any one of claims 1 to 8, wherein the cover plate includes a cover plate body and a boss, the cover plate body covers one end of the through hole, the boss is provided on one surface of the cover plate body facing the electrode assembly and extends into the through hole, and the conductive portion is connected to the boss.

10. The battery cell according to claim 9, wherein the height to which the boss protrudes from the surface of one side of the cover plate body is 1 mm to 5 mm, and selectively 1.5 mm to 3 mm.

11. The battery cell according to any one of claims 9 to 10, wherein the boss is fitted to one end of the through hole, the fitting gap between the boss and the through hole is 0 to 0.1 mm, and selectively, the fitting gap between the boss and the through hole is 0.05 mm or less.

12. The pole column is a negative pole column, the cover plate body and the boss are separate components, and the materials of the cover plate body and the boss are different. The battery cell according to any one of claims 9 to 11, wherein the material of the boss is the same as the material of the conductive part, and when the boss is welded to the conductive part, the depth of the molten pool on the cover plate is less than the thickness of the boss.

13. The battery cell according to any one of claims 9 to 12, wherein the pole column is a positive pole column, the boss and the cover plate body are integrally molded, and when the cover plate is welded to the conductive part, the depth of the molten pool on the boss is greater than the thickness of the boss.

14. The battery cell according to any one of claims 1 to 8, wherein the pole is welded to the cover plate.

15. The battery cell according to any one of claims 1 to 8, wherein the pole column is hollow and annular and the through hole is defined on the inside.

16. The pole column includes a pole column body, a first ring, and a second ring. The pole column body is annular and has the through hole defined on its inner side. The first ring is connected to one end of the pole column body facing the electrode assembly, and the first ring extends outward along the radial direction of the pole column body and extends in an annular shape along the circumferential direction of the pole column body. The battery cell according to any one of claims 1 to 8, wherein the second ring is connected to the other end of the pole body opposite to the electrode assembly, and the second ring extends outward along the radial direction of the pole body and extends in an annular shape along the circumferential direction of the pole body.

17. A battery cell according to any one of claims 1 to 8, wherein a groove is formed on the surface of the pole column opposite to the electrode assembly, the through hole is formed inside the groove and penetrates the bottom wall of the groove, and the cover plate is provided inside the groove.

18. The battery cell according to claim 17, wherein, in the direction toward the cover plate from the electrode assembly, the side wall of the groove extends inclined outward along the radial direction of the through hole.

19. The battery cell according to any one of claims 17 to 18, wherein the surface of the cover plate opposite to the electrode assembly is flush with the end face of the electrode column opposite to the electrode assembly.

20. The battery cell according to any one of claims 1 to 8, wherein the active material coated portion includes a current collector and an active material layer provided on the current collector, the conductive portion includes a tab portion electrically connected to the current collector, the tab portion includes a plurality of tab pieces, the tab pieces closer to the current collector are bundled together to form a first convergence portion, the tab pieces further from the current collector are bundled together and connected to form a second convergence portion, the first convergence portion connects the second convergence portion and the active material coated portion, and at least a portion of the second convergence portion is housed in the through hole.

21. The battery cell according to claim 20, wherein the conductive portion is fixedly connected to the cover plate via the second convergence portion.

22. The battery cell according to any one of claims 20 to 21, wherein at least a portion of the first convergence portion is housed in the through hole.

23. The active material coated portion includes a current collector and an active material layer provided on the current collector, the conductive portion includes a tab portion electrically connected to the current collector, the tab portion includes a plurality of tab pieces, the tab pieces closer to the current collector are bundled together to form a first convergence portion, the tab pieces further from the current collector are bundled and connected together to form a second convergence portion, the first convergence portion connects the second convergence portion and the active material coated portion, The battery cell according to any one of claims 1 to 8, wherein the conductive portion further includes a connecting piece, the connecting piece is connected to the second convergence portion, the conductive portion is electrically connected to the cover plate via the connecting piece, and at least a portion of the connecting piece is housed in the through hole.

24. At least a portion of the second convergence portion is located within the through hole, or The battery cell according to claim 23, wherein the second convergence portion is entirely located within the through-hole, and at least a portion of the first convergence portion is located within the through-hole.

25. The battery cell according to any one of claims 20 to 22, wherein the second convergence portion extends along the surface of the cover plate, and in the direction from the electrode assembly toward the cover plate, one end of the first convergence portion is connected to the active material coating portion, and the other end of the first convergence portion extends inclined toward the peripheral wall of the through hole and extends to one end of the second convergence portion and is connected.

26. One end of the conductive part is passed through the through-hole of the pole column, and then extends from the other side of the pole column. The one end of the conductive part is welded to the cover plate on the other side of the pole column, The cover plate is placed over one end of the through hole, and the conductive part is housed inside the through hole. A method for manufacturing a battery cell, comprising fixing and connecting a cover plate to the pole column.

27. Welding one end of the conductive part to the cover plate on the other side of the pole column is, The other end of the conductive part is pressed against the surface of one side of the cover plate, A method for manufacturing a battery cell according to claim 26, comprising laser welding the other end of the conductive portion to the cover plate.

28. A battery comprising a battery cell according to any one of claims 1 to 25, or a battery cell manufactured by the method for manufacturing a battery cell according to claim 26 or 27.

29. An electrical device comprising a battery according to claim 28 for supplying electrical energy.

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