Battery cells, batteries and electrical devices

Abstract

The battery cell, battery, and electrical device are related to the technical field of batteries. The battery cell includes a casing assembly and a battery core assembly, the casing assembly includes a casing and a first pole mounted in the casing, the battery core assembly includes a conductive part housed in the casing and electrically connected to the first pole, the conductive part includes a plurality of tab sheets arranged in a stacked manner and connected convergingly, the plurality of conductive parts are electrically connected to the first pole, and the first pole has a plurality of through holes, each of which is provided with at least one conductive part.

Description

Technical Field

[0001] Cross-Reference to Related Applications The present application is filed based on a Chinese patent application with application number 202321139017.6 and a filing date of May 11, 2023, claims priority to the above Chinese patent application, and the entire content of the above Chinese patent application is incorporated herein by reference.

[0002] The present application relates to the technical field of batteries, and specifically relates to a battery cell, a battery, and an electric device.

Background Art

[0003] In recent years, new energy vehicles have achieved leap-forward development. In the field of electric vehicles, batteries, as the power source of electric vehicles, play an irreplaceable and important role. Usually, a battery includes a plurality of battery cells. At present, since it is difficult to improve the energy density of battery cells, it becomes difficult to extend the cruising range of vehicles.

Summary of the Invention

[0004] Embodiments of the present application provide a battery cell, a battery, and an electric device that are advantageous for improving the energy density of the battery cell.

[0005] In a first aspect, embodiments of the present application provide a battery cell. The battery cell includes a casing assembly and a battery core assembly. The casing assembly includes a casing and a first pole post mounted on the casing. The battery core assembly includes a conductive part that is accommodated in the casing and electrically connected to the first pole post. The conductive part includes a plurality of tab sheets that are arranged in a stacked manner and converged and connected. A plurality of conductive parts are electrically connected to the first pole post, and the first pole post is provided with a plurality of through holes, wherein at least one conductive part is respectively arranged to penetrate through each through hole.

[0006] In the above proposed technology, since multiple conductive parts are electrically connected to the first pole, the number of conductive parts of the same polarity in the battery cell is multiple. Furthermore, since each conductive part is equipped with multiple tab sheets that are stacked and connected in a converged manner, the number of tab sheets provided in each conductive part can be reduced, and the convergence height of the multiple tab sheets in each conductive part can be reduced. This reduces the space occupied by each conductive part along the extension direction of the tabs within the casing, and if the dimensions of the casing are constant, the usable space in the extension direction of the tabs in the active material coated part can be improved, which is advantageous for improving the energy density of the battery cell. Furthermore, by installing multiple conductive parts electrically connected to the first pole column and having multiple through holes, with at least one conductive part drilled in each through hole, the conductive parts electrically connected to the first pole column can all be at least partially housed within the first pole column and occupy the space of the first pole column, thereby further reducing the space occupied by the conductive parts within the casing. Moreover, compared to a method in which all conductive parts electrically connected to the first pole column are concentrated and penetrate through a single through hole, the present invention is advantageous in that the dimensions of each through hole are small, thereby improving the adverse effect on the structural strength of the first pole column caused by the relatively large dimensions of the through holes. Furthermore, by providing multiple through-holes, the conductive part can flexibly select the through-holes. For example, if the distances between the multiple through-holes and the conductive part are different, the conductive part may extend from the relatively closer through-hole, which is advantageous in shortening the extension length of the conductive part and further reducing the space occupied by the conductive part within the casing. Moreover, for example, the conductive part may extend from the through-holes that have a relatively small number of holes drilled in them, which facilitates assembly and improves the problem of some through-holes being relatively large, thereby improving the structural strength of the first pole column.

[0007] In some embodiments, the battery core assembly comprises at least one electrode assembly, each electrode assembly having a conductive portion, and each electrode assembly having a through hole at a position corresponding to each electrode assembly on the first pole.

[0008] In the above proposed technology, the conductive portion extending from the electrode assembly can pass through a through-hole installed corresponding to the electrode assembly, thereby effectively shortening the extension length of the conductive portion within the casing, reducing the space occupied by the conductive portion within the casing, and thus advantageous in improving the energy density of the battery cell. Alternatively, some conductive portions may be selected to pass through through-holes installed corresponding to adjacent electrode assemblies, depending on the situation, thereby improving manufacturing flexibility.

[0009] In some embodiments, the electrode assembly comprises an active material coated portion, and the conductive portion comprises a convergent portion and a connecting portion, the convergent portion being formed by the convergence of a plurality of tab sheets, the connecting portion being formed by the convergence and connection of a plurality of tab sheets, the connecting portion being used to electrically connect to a first electrode column, the convergent portion connecting the connecting portion and the active material coated portion, the connection position between the convergent portion and the connecting portion being a connection base, and the first electrode column having a through hole at a position corresponding to at least one connection base of each electrode assembly.

[0010] In the above proposed technology, at least one conductive part can pass through a through-hole corresponding to its connection base, thereby shortening the extension length of the connection part within the casing of the conductive part, reducing the space occupied by the conductive part within the casing, and thus advantageous in improving the energy density of the battery cell.

[0011] In some embodiments, the first pole column is provided with through holes corresponding to intermediate regions in the thickness direction of each electrode assembly.

[0012] In the above-described technical proposal, by positioning the through-hole towards the center or nearly towards the center of the electrode assembly, regardless of where the conductive portion on the electrode assembly extends from or how many portions it extends from, it can all be relatively close to the centrally positioned through-hole. This prevents the conductive portion from extending too far before penetrating the through-hole, and further reduces the space occupied by each conductive portion within the casing.

[0013] In some embodiments, the electrode assembly comprises an active material coated portion, and the conductive portion comprises a convergent portion and a connecting portion, the convergent portion being formed by the convergence of a plurality of tab sheets, the connecting portion being formed by the convergence and connection of a plurality of tab sheets, the connecting portion being used to electrically connect to a first electrode column, the convergent portion connecting the connecting portion and the active material coated portion, the connection position between the convergent portion and the connecting portion being a connection root, and at least one connection root of the electrode assembly corresponding to an intermediate region in the thickness direction of the electrode assembly.

[0014] In the above proposed technology, by converging the tab sheet of at least one conductive part of the electrode assembly towards the center or nearly towards the center, the convergence height of the conductive part is reduced, which is advantageous in reducing the occupancy dimension of the conductive part along the extension direction of the tab within the casing, and is advantageous in improving the energy density of the battery cell. Furthermore, the distance between the centrally converged conductive part and each through-hole corresponding to the corresponding electrode assembly may be relatively short, thereby preventing the conductive part from extending too far before penetrating the through-hole, and further reducing the space occupied by each conductive part within the casing.

[0015] In some embodiments, the battery core assembly comprises at least one combination, each combination comprising two electrode assemblies, each electrode assembly in each combination comprising a plurality of conductive parts of the same polarity, and at least two conductive parts of the same polarity belonging to different electrode assemblies and arranged adjacently in each combination are connected and installed.

[0016] In the above proposed technology, by connecting and installing at least two conductive parts of the same polarity that belong to different electrode assemblies and are arranged adjacent to each other in each combination, it is possible to balance the number of conductive parts and the convergence height, thereby preventing the number of through holes from becoming excessive, ensuring the structural strength of the first pole column, and reducing the space occupied by the conductive part tabs in the casing in the extending direction.

[0017] In some embodiments, the battery core assembly comprises at least one electrode assembly, each electrode assembly comprising at least one conductive portion, the electrode assembly comprising an active material coated portion, the conductive portion comprising a convergent portion and a connecting portion, the convergent portion being formed by the convergence of a plurality of tab sheets, the connecting portion being formed by the convergence and connection of a plurality of tab sheets, the connecting portion being used to electrically connect to a first electrode column, the convergent portion connecting the connecting portion and the active material coated portion, the connection position between the convergent portion and the connecting portion being a connection base, and the conductive portion being drilled in one through hole closest to the corresponding connection base.

[0018] In the above proposed technology, by drilling each conductive part into the through-hole closest to its connection base, the conductive part selects and extends to the relatively closer through-hole, which is advantageous in shortening the length of the conductive part within the casing before it penetrates the through-hole, which is advantageous in reducing the space occupied by the conductive part within the casing, improving the energy density of the battery cell, and reducing the redundancy of the conductive part within the casing, thereby effectively reducing the redundancy of the conductive part within the casing and the risk of short-circuiting with the active material coated part, and improving the reliability of the battery cell.

[0019] In some embodiments, through holes are provided at positions corresponding to the connection bases of each conductive part on the first pole column.

[0020] In the above proposed technology, each conductive part can pass through a through-hole corresponding to its connection base, thereby shortening the extension length of the connection part of each conductive part within the casing and reducing the space occupied by each conductive part within the casing, which is advantageous for further improving the energy density of the battery cell. In addition, it is advantageous for improving the reliability of the battery cell by reducing the redundancy of each conductive part within the casing, thereby more effectively reducing the redundancy of the conductive parts within the casing and the risk of short circuits with the active material coated part.

[0021] In some embodiments, the through-hole is an elongated hole, the conductive portion comprises a connecting portion drilled in the through-hole, the connecting portion is sheet-like and the length direction of the portion located within the through-hole coincides with the length direction of the through-hole, and the width direction of the through-hole coincides with the thickness direction of the connecting portion.

[0022] In the above proposed technology, by setting the through-hole in an elongated shape that substantially matches the shape of the connection portion of the conductive part, the connection portion of the conductive part can easily pass through the through-hole, and the space remaining in the through-hole after the conductive part has passed through it can be relatively small. This reduces the size of the through-hole, making it easier to seal subsequent through-hole locations and is advantageous in improving the structural strength of the first pole column.

[0023] In some embodiments, the spacing direction of the multiple through holes on the first pole column is different from the length direction of the through holes.

[0024] In the above proposed technology, the multiple through holes on the first pole column can be arranged at intervals along a direction intersecting the longitudinal direction of the through holes. This reduces the spatial occupancy of the multiple through holes relative to the first pole column in the longitudinal direction of the through holes, which is advantageous in reducing the dimensions of the first pole column in the longitudinal direction of the through holes.

[0025] In some embodiments, the conductive portion is composed of a plurality of tab sheets, and the tab sheets are welded to the first pole column, or the conductive portion further includes an adapter sheet, and the tab sheets are connected to the first pole column via the adapter sheet.

[0026] In the above proposed technology, if the conductive part is composed of multiple tab sheets and the tab sheets are welded to the first pole column, the structure and processing of the conductive part can be simplified. If the conductive part further includes an adapter sheet and the tab sheets are connected to the first pole column via the adapter sheet, the adapter sheet may be welded to the first pole column while avoiding the part connected to the tab sheet, thereby making the weld between the adapter sheet and the first pole column firmer and reducing the likelihood of welding cracks.

[0027] In some embodiments, the first pole post has a receiving groove communicating with the through hole, and a part of the conductive portion penetrates through the through hole and is received in the receiving groove.

[0028] In the above technical solution, since the first pole post is provided with the receiving groove, the weight of the first pole post can be reduced, which is beneficial to improving the gravimetric energy density of the battery cell; moreover, by accommodating the local part of the conductive portion in the receiving groove, the space occupation inside the casing is reduced, which is beneficial to increasing the volume of the active material coating portion and improving the volumetric energy density of the battery cell.

[0029] In some embodiments, the first pole post includes an end wall and a side wall, the end wall is located on a side of the side wall adjacent to the inside of the casing, the end wall and the side wall enclose to form the receiving groove, the groove opening of the receiving groove is open toward a side away from the inside of the casing, a plurality of through holes are all opened in the end wall to communicate the receiving groove with the inside of the casing, and the outer end portion of the conductive portion is inserted into the receiving groove from the through hole and connected to the end wall.

[0030] In the above technical solution, since the receiving groove is open toward the side of the first pole post away from the inside of the casing, the conductive portion and the end wall can be welded through the receiving groove from the outside of the first pole post, that is, the side of the first pole post away from the active material coating portion, which is also beneficial to externally welding the first pole post and the conductive portion through the receiving groove, facilitating the processing and manufacturing of the battery cell, and saving the processing and manufacturing costs.

[0031] In some embodiments, the outer end portions of the plurality of conductive portions connected to the end wall are stacked and connected to be disposed on the end wall, or the outer end portions of the plurality of conductive portions connected to the end wall are disposed at intervals on the end wall.

[0032] In the above proposed technology, if the outer ends of multiple conductive parts connected to the end wall are stacked and connected to the end wall, it is advantageous for miniaturizing the first pole column. If the outer ends of multiple conductive parts connected to the end wall are installed at intervals on the end wall, it is advantageous for improving the reliability of the electrical connection between each conductive part and the first pole column.

[0033] In some embodiments, the casing assembly further comprises a pole column cover plate which fits with the first pole column and seals the groove, and the pole column cover plate is electrically connected to the first pole column.

[0034] In the above proposed technology, by installing a pole column cover plate and sealing the groove opening of the housing groove, leakage of the electrolyte from the casing through the groove opening can be prevented. Furthermore, since the pole column cover plate seals the groove opening of the housing groove and is electrically connected to the first pole column, an indirect electrical connection between the first pole column and the bus member can be easily achieved using the pole column cover plate. This is also advantageous in increasing the connection area of ​​the electrical connection and, consequently, in reducing the resistance of the electrical connection.

[0035] In some embodiments, the casing is provided with multiple pole columns, at least one of which is the first pole column.

[0036] In the above proposed technology, by setting at least one of all the poles of the casing assembly as the first pole, some of the first poles in the entire battery cell may have multiple through holes, or all of them may have multiple through holes, thereby meeting manufacturing needs, cost needs, etc. Depending It can be flexibly selected and combined.

[0037] In a second aspect, the embodiment of the present application further provides a battery including the above-mentioned battery cell.

[0038] In the above proposed technology, the above-mentioned battery cells are installed in the battery, and the energy density of the battery cells can be improved, which is advantageous for improving the energy density of the battery.

[0039] In a third aspect, the embodiment of the present application further provides an electrical device including the battery described above.

[0040] In the above proposed technology, by installing the battery in the electrical device, the energy density of the battery can be improved, which is advantageous in extending the operating time of the electrical device.

[0041] To further clarify the technical concept of the embodiments of this application, the drawings used in the embodiments are briefly introduced below. However, it should be understood that these drawings only show some embodiments of this application and should therefore not be considered limiting in scope. Those skilled in the art can obtain other relevant drawings based on these drawings without any creative work. [Brief explanation of the drawing]

[0042] [Figure 1] This is a schematic diagram of the structure of an electrical device in a vehicle provided by some embodiments of the present application. [Figure 2] This is an exploded view of the structure of a battery cell used in a battery provided by some embodiments of the present invention. [Figure 3] This is a perspective view of a battery cell provided by some embodiments of the present application. [Figure 4] Figure 3 is an exploded view of a partial configuration of the battery cell shown. [Figure 5] Figure 4 is a close-up view of area A. [Figure 6] Figure 3 is an orthographic projection of the battery cell shown. [Figure 7] This is a cross-sectional view along line BB in Figure 6. [Figure 8] Figure 7 is a close-up view of area C. [Figure 9]This is a local cross-sectional view of a battery cell provided by some embodiments of the present application. [Figure 10] This is a local cross-sectional view of a battery cell provided by some embodiments of the present application. [Figure 11] This is a perspective view of the first pole column provided by some embodiments of the present application. [Figure 12] Figure 11 is an orthographic projection of the first polar column. [Figure 13] Figure 12 is a cross-sectional view along the DD line. [Figure 14] This is an orthographic projection of a battery cell provided by some embodiments of the present application. [Figure 15] Figure 14 is a close-up view of area E. [Figure 16] This is a local cross-sectional view of a battery cell provided by some embodiments of the present application. [Explanation of Symbols]

[0043] Electrical device 1000, battery 100, controller 200, motor 300, case 20, first case 201, second case 202, battery cell 10, casing assembly 1, casing 11, first pole column 12, through hole 121, end wall 122, side wall 123, housing groove 124, groove opening 1241, outer end face of pole column 125, pole column cover plate 13, battery core assembly 2, electrode assembly 20, intermediate region 201, active material coated part 21, conductive part 22, tab sheet 220, convergence part 221, connection part 222, connection base part 223, outer end of conductive part 224, adapter sheet 225, first direction Z, second direction X, third direction Y. [Modes for carrying out the invention]

[0044] To further clarify the purpose, technical proposal, and advantages of the embodiments of this application, the technical proposal of the embodiments will be clearly described below in conjunction with the drawings of the embodiments of this application. However, it should be clear that the embodiments described are only a selection of embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained without creative work by a person skilled in the art fall within the scope of protection of this application.

[0045] Unless otherwise defined, all technical and scientific terms used in this Application have the same meaning as those generally understood by those skilled in the art relating to the Application. Terms used in the Specification of this Application are solely for the purpose of describing specific embodiments and are not intended to limit this Application. The terms “including” and “having,” and any variations thereof, in the description of the Specification, Claims, and the Drawings, are intended to cover non-exclusive inclusion. Terms such as “first,” “second,” etc., in the Specification, Claims, or the Drawings are used to distinguish different subjects and are not intended to indicate a particular order or priority.

[0046] The “Examples” as used in this Application mean that certain features, structures, or characteristics described in conjunction with the Examples may be included in at least one Example of this Application. The occurrence of such phrase at each location in the Specification does not necessarily refer to the same Example, nor do they represent mutually exclusive, independent, or substitutable Examples.

[0047] In this application, the term "and / or" simply describes a related relationship that explains the 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 addition, the symbol " / " in this application generally indicates that the preceding and following related objects are in an "or" relationship.

[0048] In the embodiments of this application, the same drawing symbols represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the dimensions such as thickness, length, and width of various components in the embodiments of this application shown in the attached drawings, as well as the overall thickness, length, and width of the integrated device, are merely illustrative and should not constitute limitations of this application.

[0049] In this application, "multiple" refers to two or more (including two).

[0050] In this application, the battery cell may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, and the embodiments of this application are not limited to these. The battery cell may be cylindrical, flattened, rectangular, or have other shapes, and the embodiments of this application are not limited to these either. Battery cells are generally classified into three types according to the encapsulation method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, but the embodiments of this application are not limited to these either.

[0051] Exemplary, a battery cell may generally comprise a casing, a battery core assembly, and an electrolyte. The casing is used to house the battery core assembly and the electrolyte. The casing is provided with electrode posts, which are generally multiple and comprise at least one positive electrode post and at least one negative electrode post. The battery core assembly includes one or more electrode assemblies, which are formed by laminating or winding positive electrode pieces, negative electrode pieces, and separator films.

[0052] In this configuration, the positive electrode section generally includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is applied directly or indirectly to the positive electrode current collector, and the positive electrode current collector not coated with the positive electrode active material layer protrudes from the positive electrode current collector coated with the positive electrode active material layer, forming a positive electrode tab sheet. Multiple positive electrode tab sheets are stacked and electrically connected to a positive electrode column. Exemplarily, multiple stacked positive electrode tab sheets can be directly welded to a positive electrode column to form an electrical connection, or the battery core assembly may include a positive electrode adapter sheet, in which multiple stacked positive electrode tab sheets are welded to one end of the positive electrode adapter sheet, and the other end of the positive electrode adapter sheet is welded to a positive electrode column, thereby electrically connecting the positive electrode tab sheet and the positive electrode column.

[0053] The negative electrode piece generally includes a negative electrode current collector and a negative electrode active material layer, where the negative electrode active material layer is applied directly or indirectly to the negative electrode current collector, and a negative electrode current collector without the negative electrode active material layer protrudes from the negative electrode current collector with the negative electrode active material layer, and a positive electrode current collector without the negative electrode active material layer is used as a negative electrode tab sheet, with multiple negative electrode tab sheets laminated together and electrically connected to a negative electrode column. Exemplarily, multiple laminated negative electrode tab sheets can be directly welded to a negative electrode column to form an electrical connection, or the battery core assembly may include a negative electrode adapter sheet, where multiple laminated negative electrode tab sheets are welded to one end of the negative electrode adapter sheet, and the other end of the negative electrode adapter sheet is welded to a negative electrode column, thereby electrically connecting the negative electrode tab sheet and the negative electrode column.

[0054] The material of the separator film is not particularly limited and may be, for example, polypropylene or polyethylene.

[0055] At the same time, a battery cell functions primarily by relying on the movement of metal ions between the positive and negative electrode pieces. Taking a lithium-ion battery as an example, the material of the positive electrode current collector may be aluminum, the material of the positive electrode active material layer may be lithium cobalt oxide, lithium iron phosphate, lithium ternary, or lithium manganese oxide, the material of the negative electrode current collector may be copper, and the material of the negative electrode active material layer may be carbon or silicon. During the charging and discharging process, Li+ ions repeatedly insert and remove between the two electrodes. During charging, Li+ ions are removed from the positive electrode and inserted into the negative electrode via the electrolyte, making the negative electrode lithium-rich, and the reverse occurs during discharging.

[0056] The batteries referred to in the embodiments of this application refer to a single physical module containing one or more battery cells to provide higher voltage and capacity. For example, the batteries referred to in this application may be battery modules or battery packs. Battery modules generally contain multiple battery cells. Battery packs generally include a case for enclosing one or more battery cells or one or more battery modules. The case can prevent liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0057] In a battery, multiple battery cells can be connected in series, parallel, or series-parallel, with series-parallel connection meaning that multiple battery cells have both series and parallel connections. Multiple battery cells can be directly connected in series, parallel, or series-parallel, and the entire assembly of multiple battery cells may be housed in a case, or the battery may be in a form in which multiple battery cells are first connected in series, parallel, or series-parallel to form a battery module, and the multiple battery modules are further connected in series, parallel, or series-parallel to form a single unit and housed in a case.

[0058] In related technologies, a battery cell is manufactured by applying an active material to a current collector and then cutting it to obtain electrode pieces consisting of a current collector coated with an active material layer (referred to as the active material coated portion) and a current collector without an active material layer (referred to as a tab sheet). Next, the positive and negative electrode pieces and a separator film are sequentially laminated or wound to obtain one electrode assembly. The active material coated portion of the electrode assembly is welded to the electrode column via a conductive portion. The conductive portion may be a tab portion formed by laminating and winding tab sheets of the same polarity in the electrode assembly, or it may be composed of both the tab portion and an adapter sheet welded to the tab portion.

[0059] Generally, multiple electrode assemblies are provided within the casing of a battery cell. When processing the tab portion, tab sheets of the same polarity in multiple electrode assemblies are all stacked together. As a result, the number of tab sheets in the tab portion is relatively large, and the convergence height of the tab portion formed by convergence and connection is relatively large (the convergence height refers to the vertical distance from the starting position of the convergence connection of the tab sheets to the active material coated portion, and the direction of this vertical distance is referred to as the extension direction of the tab). Therefore, the dimensions occupied by the tab portion within the casing along the extension direction of the tab are relatively large. If the dimensions of the casing are constant, this affects the space that the active material coated portion can occupy in the extension direction of the tab, making it difficult to improve the energy density of the battery cell. Furthermore, when all tab sheets of the same polarity are converged together, the greater the deformation of the tab sheet of the electrode piece farther from the starting position of the convergence connection (i.e., the edge tab sheet), the greater the risk of cracking.

[0060] Based on the above considerations, in order to improve the energy density of the battery cell, the present invention designs a battery cell in which the number of conductive parts of the same polarity in the battery cell is set to multiple, and each conductive part is provided with multiple tab sheets that are stacked and connected in a converged manner, thereby reducing the number of tab sheets provided in each conductive part, and further reducing the convergence height of the tabs in each conductive part, thereby reducing the space occupied by each conductive part along the extension direction of the tabs within the casing, and when the dimensions of the casing are constant, the space that the active material coated part can occupy in the extension direction of the tabs can be improved, which is advantageous in improving the energy density of the battery cell. Furthermore, deformation of the tab sheets at the edge position of the conductive part can be reduced to some extent, and the risk of cracking of the tab sheets can be reduced.

[0061] Furthermore, in the embodiment of the present invention, a plurality of through holes are provided in at least one pole column, and at least one conductive part electrically connected to the pole column is drilled in each through hole, thereby enabling the pole column to accommodate at least a portion of the conductive part, further reducing the space occupied by the conductive part within the casing, further improving the usable space of the active material coated part within the casing, and further improving the energy density of the battery cell. Moreover, by providing a plurality of through holes, the conductive part can flexibly select the through holes. For example, if the distances between the plurality of through holes and the conductive part are different, the conductive part may select a relatively close through hole and extend from there, which is advantageous in shortening the extension length of the conductive part within the casing, further reducing the space occupied by the conductive part within the casing. Also, for example, the conductive part may choose to extend from a through hole with a relatively small number of conductive parts, thereby facilitating assembly and improving the problem of some through holes being relatively large, and improving the strength of the pole column.

[0062] Embodiments of the present application provide an electrical device that uses the battery of the present application as a power source, and the electrical device may be, but is not limited to, a mobile phone, tablet, laptop computer, electric toy, power tool, electric scooter, electric car, ship, or aerospace aircraft. Among these, electric toys may include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and aerospace aircraft may include airplanes, rockets, space shuttles, or spacecraft.

[0063] For the sake of explanation, the following embodiments will use a vehicle as an example to describe in detail the structure of the electrical device, battery, and battery cell of the present invention.

[0064] Referring to Figure 1, Figure 1 is a schematic diagram of the structure of an electrical device 1000, which is a vehicle provided in some embodiments of the present application. The vehicle may be a fuel vehicle, a 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 100 is installed in the vehicle, and the battery 100 may be installed in the bottom, head, or tail of the vehicle. The battery 100 is used to supply power to the vehicle, and for example, the battery 100 can function as the operating power source of the vehicle. The vehicle may further include a controller 200 and a motor 300, the controller 200 controlling the battery 100 to supply power to the motor 300, and is used, for example, to meet the operating power needs of the vehicle during starting, navigation, and driving. In some embodiments of the present application, the battery 100 can be used not only as the operating power source of the vehicle but also as the driving power source of the vehicle, and can provide driving force to the vehicle in place of or in part of fuel or natural gas.

[0065] Referring to Figure 2, Figure 2 is an exploded view of a structure in which a battery cell 10 provided in several embodiments of the present application is used in a battery 100. The battery 100 includes a case 20 and a plurality of battery cells 10, the battery cells 10 being housed in the case 20. The case 20 provides assembly space for the battery cells 10, and the case 20 can employ various structures. In some embodiments, the case 20 may include a first case 201 and a second case 202, the first case 201 and the second case 202 covering each other, and together the first case 201 and the second case 202 limit the assembly space for housing the battery cells 10. The second case 202 may be a hollow structure with one end open, and the first case 201 may be a plate-like structure, with the first case 201 covering the open side of the second case 202 so that the first case 201 and the second case 202 jointly limit the assembly space. Alternatively, both the first case 201 and the second case 202 may be hollow structures with one side open (for example, as shown in Figure 2), with the open side of the first case 201 covering the open side of the second case 202. Naturally, the case 20 formed by the first case 201 and the second case 202 may have various shapes, such as a cylinder or a rectangular parallelepiped.

[0066] Referring to Figure 3, which is a schematic diagram of a battery cell 10 provided in several embodiments of the present application, the battery cell 10 is a rectangular parallelepiped, and the width direction of the battery cell 10 is the first direction Z, the length direction of the battery cell 10 is the second direction X, and the thickness direction of the battery cell 10 is the third direction Y. The first direction Z, the second direction X, and the third direction Y are perpendicular to each other in pairs. However, the present application is not limited thereto, and in other embodiments, the battery cell 10 may have other shapes such as cylindrical, flattened, or prismatic structures.

[0067] Referring to Figure 4, Figure 4 is an exploded view showing a partial configuration of the battery cell shown in Figure 3. In the embodiment of this application, the battery cell 10 comprises a casing assembly 1 and a battery core assembly 2. The casing assembly 1 comprises a casing 11 and a first pole column 12 installed in the casing 11, and the battery core assembly 2 is housed in the casing 11. The shape of the casing 11 can be adjusted according to the type of battery cell 10, and the type of battery cell 10 in the embodiment of this application is not particularly limited. For example, if the battery cell 10 is a prismatic battery, the casing 11 will be prismatic, and if the battery cell 10 is a cylindrical battery, the casing 11 will be cylindrical. In the embodiment of this application, the casing 11 will be described as prismatic in all cases.

[0068] The casing 11 is provided with electrode posts, which are used for electrical connection to the battery core assembly 2 to ensure that the charging and discharging operations of the battery cell 10 are performed normally. Generally, there are at least two electrode posts, specifically consisting of at least one positive electrode post and at least one negative electrode post. For example, if there are two electrode posts, one is a positive electrode post and the other is a negative electrode post, and each is electrically connected to the positive and negative output positions of the battery core assembly 2. If there are four electrode posts, two may be positive electrode posts and the remaining two may be negative electrode posts, with both positive electrode posts electrically connected to the positive electrode output positions of the battery core assembly 2 and both negative electrode posts electrically connected to the negative electrode output positions of the battery core assembly 2.

[0069] In the embodiment of the present application, at least one of the plurality of poles on the casing 11 is a first pole 12, and the first pole 12 may be a positive pole or a negative pole. Referring to Figures 5 to 8, Figure 5 is a localized enlarged view of location A shown in Figure 4, Figure 6 is an orthographic projection of the battery cell 10 shown in Figure 3, Figure 7 is a cross-sectional view along line BB in Figure 6, and Figure 8 is a localized enlarged view of location C shown in Figure 7. The battery core assembly 2 includes conductive parts 22, each first pole column 12 is electrically connected to a plurality of conductive parts 22, and the first pole column 12 has a plurality of through holes 121, each through hole 121 having at least one conductive part 22 drilled in it, and the plurality of conductive parts 22 that are electrically connected to the first pole column 12 are all at least partially housed in the first pole column 12, occupying space within the first pole column 12, saving space occupied by the conductive parts 22 within the casing 11, and is advantageous for further improving the energy density of the battery cell 10.

[0070] When multiple poles are provided on the casing 11, all of the poles on the casing 11 may be first poles 12 to which multiple conductive parts 22 are electrically connected, some of the poles on the casing 11 may be first poles 12 to which multiple conductive parts 22 are electrically connected, and if some of the poles on the casing 11 are first poles 12 to which multiple conductive parts 22 are electrically connected, the remaining poles on the casing 11 are second poles (not shown) to which one conductive part 22 is electrically connected. Regardless of whether the poles on the casing 11 are first poles 12 or second poles, both the first poles 12 and the second poles are electrically connected to the battery core assembly 2 to ensure that the charging and discharging process of the battery cell 10 is carried out normally. To simplify the description, the following description will primarily use the example of a casing 11 having multiple poles, all of which are first poles 12, that is, each pole is electrically connected to multiple conductive parts 22.

[0071] In the embodiment of the present invention, the battery core assembly 2 includes an active material coated portion 21, which is housed within the casing 11. The active material coated portion 21 is the portion of the battery core assembly 2 to which the active material is coated, and can assist in the desorption of metal ions during the charging and discharging process of the battery cell 10. The conductive portion 22 is a metal structure that electrically connects the active material coated portion 21 and the electrode post. The conductive portion 22 is not coated with the active material, and both the first electrode post 12 and the second electrode post can be electrically connected to the active material coated portion 21 via the conductive portion 22, so that the charging and discharging operations of the battery cell 10 can be performed.

[0072] To make it clear, the active material coating section 21 is divided into a positive electrode active material coating section and a negative electrode active material coating section. The positive electrode active material coating section includes a portion of the positive electrode current collector to which the positive electrode active material layer is coated, and the negative electrode active material coating section includes a portion of the negative electrode current collector to which the negative electrode active material layer is coated. The conductive section 22 is divided into a positive electrode conductive section and a negative electrode conductive section. The positive electrode conductive section electrically connects the positive electrode active material coating section and the positive electrode column, and the negative electrode conductive section electrically connects the negative electrode active material coating section and the negative electrode column.

[0073] Referring again to Figures 5 and 8, in the embodiment of the present invention, the conductive portion 22 comprises a plurality of tab sheets 220 that are stacked and connected in a converged manner. Specifically, the conductive portion 22 comprises a converged portion 221 and a connecting portion 222. The converged portion 221 is formed by the convergence of a plurality of tab sheets 220, and the connecting portion 222 is formed by the convergence and connection of a plurality of tab sheets 220. The converged portion 221 connects the connecting portion 222 to the active material coated portion 21. In other words, when forming the converged portion 221, the plurality of tab sheets 220 simply come together (i.e., converge in a direction toward each other) but do not connect, but when forming the connecting portion 222, the plurality of tab sheets 220 not only come together but also connect to form an integrated structure. For example, multiple tab sheets 220 can be connected to form a single plate-like structure by welding (e.g., ultrasonic welding) to form a connection portion 222, or multiple tab sheets 220 can be assembled and connected to form a connection portion 222 by methods such as bonding with a conductive adhesive.

[0074] Of these, the connection portion 222 is used to electrically connect to the first pole 12, that is, the connection portion 222 may be directly connected to the first pole 12 (for example, as shown in Figure 8) or indirectly connected (for example, as shown in Figure 9, which is a local cross-sectional view of a battery cell provided by some embodiments of the present application). In some selectable embodiments, for example, as shown in Figure 8, the conductive portion 22 may consist only of a plurality of tab sheets 220, in which case the tab sheets 220 may be welded to the first pole 12, thereby simplifying the structure and processing of the conductive portion 22. Alternatively, in other selectable embodiments, as shown in Figure 9, for example, the conductive portion 22 may further include an adapter sheet 225 in addition to the plurality of tab sheets 220, the tab sheets 220 being connected to the first pole column 12 via the adapter sheet 225, for example one end of the adapter sheet 225 being welded to the connection portion 222 and the other end of the adapter sheet 225 being welded to the first pole column 12, thereby connecting the plurality of tab sheets 220 to the first pole column 12 via the adapter sheet 225, in which case the adapter sheet 225 may be welded to the first pole column 12 while avoiding the portion connected to the tab sheets 220, thereby the adapter sheet 225 The weld between the first pole column 12 is solid, making it less prone to welding cracks.

[0075] As can be understood, the tab sheet 220 is divided into a positive electrode tab sheet 220 and a negative electrode tab sheet 220. The positive electrode tab sheets 220 that need to converge are laminated together and ultrasonically tack-welded to form the positive electrode connection portion 222, reducing the interlayer gap and forming a plate-like structure with a certain degree of rigidity from the multiple soft positive electrode tab sheets 220. Similarly, the negative electrode tab sheets 220 that need to converge are laminated together and ultrasonically tack-welded to form the negative electrode connection portion 222, thereby reducing the interlayer gap and forming a plate-like structure with a certain degree of rigidity from the multiple soft negative electrode tab sheets 220. Exemplarily, the current collector and the tab sheet 220 may be an integrated member, for example, an aluminum foil integrally molded with respect to the positive electrode piece, or a copper foil integrally molded with respect to respect to respect to respect to respect to respect to respect to respect.

[0076] Referring again to Figure 8, the connection point between the convergence portion 221 and the connection portion 222 is the connection base portion 223, the vertical distance from the connection base portion 223 to the active material coating portion 21 is the convergence height (for example, the distance H shown in Figure 8), and the direction of this vertical distance is denoted as the extension direction of the tab (for example, the first direction Z shown in Figure 8). In the embodiment of the present invention, each first pole column 12 is electrically connected to a plurality of conductive parts 22, that is, the number of conductive parts 22 of the same polarity in the battery cell 10 is plurality, that is, all the tab sheets 220 of the positive electrode in the battery cell 10 converge and connect to form a plurality of positive electrode connection parts 222, and all the tab sheets 220 of the negative electrode in the battery cell 10 converge and connect to form a plurality of negative electrode connection parts 222, and each conductive part 22 is equipped with a plurality of tab sheets 220 that are stacked and converged and connected, thereby reducing the number of tab sheets 220 provided in each conductive part 22, and further reducing the convergence height of the plurality of tab sheets 220 in each conductive part 22, thereby reducing the occupied dimension of each conductive part 22 along the extension direction of the tab within the casing 11, and when the dimensions of the casing 11 are constant, the space that the active material coated part 21 can occupy in the extension direction of the tab can be improved, which is advantageous for improving the energy density of the battery cell 10. Furthermore, the relatively small number of tab sheets 220 provided in each conductive part 22 reduces deformation of the tab sheets 220 at the edges of the conductive part 22 to some extent, thereby reducing the risk of cracking of the tab sheets 220.

[0077] Furthermore, in the embodiment of the present application, there are multiple through holes 121 on the first pole column 12, and at least one conductive part 22 is drilled in each through hole 121. Compared to an embodiment in which all conductive parts 22 electrically connected to the first pole column 12 are concentrated and pass through a single through hole 121, the embodiment of the present application is advantageous in reducing the size of each through hole 121, thereby improving the adverse effect on the structural strength of the first pole column 12 caused by the relatively large size of the through holes 121. Furthermore, by providing multiple through-holes 121, the conductive part 22 can flexibly select the through-holes 121. For example, if the distances between the multiple through-holes 121 and the conductive part 22 are different, the conductive part 22 may extend to the relatively closer through-holes 121, which is advantageous in shortening the extended length of the conductive part 22 and further reducing the space occupied by the conductive part 22 within the casing 11. Alternatively, the conductive part 22 may extend to the through-holes 121 that have a relatively small number of holes, thereby making assembly easier and improving the problem of some through-holes 121 being relatively large, thereby improving the structural strength of the first pole column 12.

[0078] In the embodiment of the present application, the number of through holes 121 on the first pole column 12 is not limited and may be, for example, two, three, four, or more. When the number of through holes 121 on the first pole column 12 is two, it is advantageous to improve the structural strength of the first pole column 12 and to increase the electrical connection area between the conductive part 22 and the first pole column 12 as much as possible.

[0079] In the embodiments of the present application, the number of conductive parts 22 electrically connected to the first pole column 12 and the number of through holes 121 may be the same or different, and the number of conductive parts 22 is equal to or greater than the number of through holes 121, thereby ensuring that at least one conductive part 22 is drilled in each through hole 121. For example, if there are two conductive parts 22 electrically connected to the first pole column 12, there may be two through holes 121 on the first pole column 12. For example, if there are three conductive parts 22 electrically connected to the first pole column 12, there may be two or three through holes 121 on the first pole column 12, and providing two through holes 121 is advantageous in improving the structural strength of the first pole column 12 and the electrical connection area with the conductive parts 22.

[0080] For example, if there are four conductive parts 22 electrically connected to the first pole column 12, the number of through holes 121 on the first pole column 12 may be two, three, or four. Providing two through holes 121 is advantageous for improving the structural strength of the first pole column 12 and the electrical connection area with the conductive parts 22. Providing four through holes 121 is advantageous for improving the energy density of the battery cell 10 by sufficiently reducing the space occupied by the conductive parts 22 within the casing 11.

[0081] Referring again to Figures 4, 7, and 8, in some embodiments of the present application, the battery core assembly 2 comprises at least one electrode assembly 20, that is, the number of electrode assemblies 20 in the battery core assembly 2 is one or more, and each electrode assembly 20 comprises a conductive part 22. For example, exemplary, if there is one electrode assembly 20, the electrode assembly 20 comprises a plurality of conductive parts 22 electrically connected to each first pole 12. Also exemplary, for example, if there are a plurality of electrode assemblies 20, each electrode assembly 20 comprises at least one conductive part 22 electrically connected to each first pole 12, and thus a plurality of electrode assemblies 20 can have a plurality of conductive parts 22 electrically connected to the first pole 12.

[0082] In the embodiments of the present application, through holes 121 are provided at positions corresponding to each electrode assembly 20 on the first pole column 12. For explanation purposes, the position of the orthographic projection of the tab of the through hole 121 along the extension direction of the tab on which electrode assembly 20 is located indicates which electrode assembly 20 the through hole 121 corresponds to. In the embodiments of the present application, for any one electrode assembly 20, there is at least one orthographic projection of the tab of the through hole 121 along the extension direction of the tab on which at least one through hole 121 is located; that is, at least one through hole 121 is provided at a position corresponding to each electrode assembly 20 on the first pole column 12.

[0083] In this way, the conductive portion 22 extending from the electrode assembly 20 can pass through the through hole 121 installed in the electrode assembly 20, thereby effectively shortening the extension length of the connecting portion 222 of the conductive portion 22 within the casing 11, reducing the space occupied by the conductive portion 22 within the casing 11, which is advantageous in improving the energy density of the battery cell 10.

[0084] However, the present application is not limited thereto, and in other embodiments of the present application, if there is already insufficient space in the through-hole 121 corresponding to a certain electrode assembly 20, or if there are a relatively large number of same-polarity conductive parts 22 extending from a certain electrode assembly 20, multiple through-holes 121 of the multiple conductive parts 22 that are close to adjacent electrode assemblies 20 may be extended through to through-holes 121 installed corresponding to adjacent electrode assemblies 20.

[0085] Referring again to Figure 8, exemplary, if through holes 121 are provided on the first pole column 12 at positions corresponding to each electrode assembly 20, the first pole column 12 has through holes 121 at positions corresponding to at least one connection root portion 223 of each electrode assembly 20, that is, the orthographic projection of the tab of the connection root portion 223 of at least one conductive portion 22 of each electrode assembly 20 along the extension direction is inside the through hole 121. This allows the conductive portion 22 to pass through the through hole 121 corresponding to its connection root portion 223, thereby shortening the extension length of the connection portion 222 of the conductive portion 22 within the casing 11, reducing the space occupied by the conductive portion 22 within the casing 11, and is advantageous in improving the energy density of the battery cell 10. It is also advantageous in reducing the redundancy of the conductive portion 22 within the casing 11, and reducing the redundancy of the conductive portion 22 within the casing 11 and the risk of short-circuiting with the active material coated portion 21.

[0086] Referring again to Figure 8, if the first pole column 12 is provided with through holes 121 at positions corresponding to each connection base portion 223 in each electrode assembly 20, it is possible to shorten the extension length of the connection portion 222 of each conductive portion 22 within the casing 11, reducing the space occupied by each conductive portion 22 within the casing 11, which is advantageous in further improving the energy density of the battery cell 10. It is also advantageous in reducing the redundancy of each conductive portion 22 within the casing 11, more effectively reducing the redundancy of the conductive portion 22 within the casing 11 and the risk of short-circuiting with the active material coated portion 21, thereby improving the reliability of the battery cell 10.

[0087] In some embodiments of the present application, referring again to Figure 8, the first pole column 12 is provided with through holes 121 corresponding to intermediate regions 201 in the thickness direction of each electrode assembly 20. That is, for any one electrode assembly 20, the orthographic projection along the extension direction of the tab of at least one through hole 121 lies in the intermediate region 201 of the corresponding electrode assembly 20. In the present application, "intermediate region 201 in the thickness direction of the electrode assembly 20" is understood in a broad sense and refers to the region between 1 / 3 of the thickness and 2 / 3 of the thickness along the thickness direction of the electrode assembly 20.

[0088] In this way, by positioning the through-hole 121 towards the center or nearly towards the center of the electrode assembly 20, regardless of where the conductive portion 22 on the electrode assembly 20 extends from or how many portions it extends from, it can all be relatively close to the centrally positioned through-hole 121. Therefore, the conductive portion 22 does not extend too far before penetrating the through-hole 121, and the space occupied by each conductive portion 22 within the casing 11 can be significantly reduced.

[0089] Referring again to Figure 8, if through holes 121 are provided at positions corresponding to each electrode assembly 20 on the first pole column 12, then, exemplary, the connection root portion 223 of at least one conductive portion 22 of the electrode assembly 20 corresponds to an intermediate region 201 in the thickness direction of the electrode assembly 20. That is, for any one electrode assembly 20, the orthographic projection along the extension direction of the tab of at least one connection root portion 223 lies in the intermediate region 201 of the corresponding electrode assembly 20.

[0090] For example, if the connection base portion 223 of the conductive portion 22 corresponds to an intermediate region 201 in the thickness direction of the electrode assembly 20, the convergence height H of the conductive portion 22 may be at least half the product of the number of tab sheets 220 provided on the conductive portion 22 and the thickness of each tab sheet 220.

[0091] This is advantageous in reducing the convergence height of the conductive portion 22 by converging the tab sheet 220 of the conductive portion 22 in the electrode assembly 20 towards the center or near the center, thereby reducing the occupied dimension of the conductive portion 22 along the extension direction of the tab within the casing 11, which is advantageous in improving the usable space in the extension direction of the tab of the active material coated portion 21, and is advantageous in improving the energy density of the battery cell 10. Furthermore, the distance between the conductive portion 22 that converges towards the center or near the center and each through hole 121 corresponding to the electrode assembly 20 can be relatively close, so that the conductive portion 22 does not extend too far before penetrating the through hole 121, and furthermore, the occupied space of each conductive portion 22 within the casing 11 can be effectively reduced.

[0092] Furthermore, if the connection base portion 223 of the conductive portion 22 in the electrode assembly 20 corresponds to the intermediate region 201 in the thickness direction of the electrode assembly 20, and through holes 121 are provided on the first pole column 12 at positions corresponding to the connection base portion 223 of each conductive portion 22, the first pole column 12 is provided with through holes 121 corresponding to the intermediate region 201 in the thickness direction of each electrode assembly 20, which is even more advantageous in reducing the distance from the conductive portion 22 to the through hole 121. This shortens the extension length within the casing 11 before the conductive portion 22 penetrates the through hole 121, thereby effectively reducing the space occupied by the conductive portion 22 within the casing 11.

[0093] Referring to Figure 10, which is a local cross-sectional view of a battery cell 10 provided in some embodiments of the present application, in which the battery core assembly 2 comprises at least one combination, each combination comprising two electrode assemblies 20, each electrode assembly 20 in each combination comprising a plurality of conductive parts 22 of the same polarity, and at least two conductive parts 22 of the same polarity belonging to different electrode assemblies 20 in each combination and arranged adjacently are connected and installed.

[0094] For example, the two electrode assemblies 20 shown in Figure 10 are a single combination, where the left electrode assembly 20 has two positive electrode conductive parts 22, and the right electrode assembly 20 also has two positive electrode conductive parts 22, and the positive electrode conductive part 22 of the left electrode assembly 20 that is adjacent to the right is connected to the positive electrode conductive part 22 of the right electrode assembly 20 that is adjacent to the left of the two positive electrode conductive parts 22.

[0095] As a result, if each electrode assembly 20 extends from two positive electrode conductive parts 22, and two electrode assemblies 20 share four independent positive electrode conductive parts 22, then four through holes 121 need to be made in the first pole column 12 of the positive electrode. However, in the above embodiment, by connecting and installing two of the positive electrode conductive parts 22, only three through holes 121 need to be made in the first pole column 12 of the positive electrode. This reduces the number of independent conductive parts 22 required for the combination to some extent, and further reduces the number of through holes 121 on the first pole column 12, thereby improving the structural strength of the first pole column 12 and improving assembly efficiency. If the thickness of both electrode assemblies 20 is relatively large, and each electrode assembly 20 extends only one positive electrode conductive portion 22, then the number of tab sheets 220 provided on the positive electrode conductive portion 22 of each electrode assembly 20 is relatively large, the convergence height in the extension direction of the tabs of the conductive portion 22 is relatively high, and the occupied space is relatively large. In contrast to such an example, the above embodiment reduces the number of tab sheets 220 provided on each conductive portion 22 by having each electrode assembly 20 extend from two positive electrode conductive portions 22, thereby reducing the occupied space in the extension direction of the tabs of each conductive portion 22.

[0096] Therefore, in the above-described technical proposal, by connecting and installing at least two conductive parts of the same polarity that belong to different electrode assemblies 20 and are arranged adjacent to each other in each combination, it is possible to achieve a balance between the number of conductive parts 22 and the convergence height, thereby preventing the number of through holes 121 from being too large, ensuring the structural strength of the first pole column 12, and reducing the space occupied by the tabs of the conductive parts 22 in the extending direction within the casing 11.

[0097] Referring again to Figure 8, in some embodiments of the present application, the conductive portion 22 is drilled in one through-hole 121 closest to the corresponding connection root portion 223. By drilling each conductive portion 22 in the through-hole 121 closest to its connection root portion 223 in this way, it is advantageous to select and extend through-holes 121 relatively close to the conductive portion 22, thereby shortening the extension length of the conductive portion 22 within the casing 11 before it penetrates the through-hole 121, reducing the space occupied by the conductive portion 22 within the casing 11, which is advantageous to improve the energy density of the battery cell 10, and also reduces the redundancy of the conductive portion 22 within the casing 11, effectively reducing the redundancy of the conductive portion 22 within the casing 11 and the risk of short-circuiting with the active material coated portion 21, which is advantageous to improve the reliability of the battery cell 10.

[0098] Referring again to Figure 8, if the first pole column 12 has through holes 121 at positions corresponding to each connection base portion 223, then each conductive portion 22 can penetrate through the through hole 121 corresponding to its connection base portion 223 over a shorter distance. This further shortens the extension length of the connection portion 222 of each conductive portion 22 within the casing 11, reducing the space occupied by each conductive portion 22 within the casing 11, which is advantageous for further improving the energy density of the battery cell 10. It is also advantageous for reducing the redundancy of each conductive portion 22 within the casing 11, more effectively reducing the redundancy of the conductive portion 22 within the casing 11 and the risk of short-circuiting with the active material coated portion 21, thereby improving the reliability of the battery cell 10.

[0099] Referring to Figures 11 to 15, Figure 11 is a perspective view of a first pole column 12 provided in some embodiments of the present application, Figure 12 is an orthographic projection of the first pole column 12 shown in Figure 11, Figure 13 is a cross-sectional view along line DD in Figure 12, Figure 14 is an orthographic projection of a battery cell 10 provided in some embodiments of the present application, and Figure 15 is a localized enlarged view of location E shown in Figure 14. In some embodiments of the present application, the through hole 121 is an elongated hole, the conductive portion 22 includes a connecting portion 222 drilled in the through hole 121, the connecting portion 222 is sheet-like and the length direction of the portion of the connecting portion 222 located within the through hole 121 coincides with the length direction of the through hole 121 (e.g., the second direction X shown in Figure 15), and the width direction of the through hole 121 (e.g., the third direction Y shown in Figure 15) coincides with the thickness direction of the connecting portion 222.

[0100] As a result, by setting the through-hole 121 in an elongated shape that substantially matches the shape of the connection portion 222 of the conductive portion 22, the connection portion 222 of the conductive portion 22 can easily pass through the through-hole 121, and the space remaining in the through-hole 121 after the conductive portion 22 has passed through it can be relatively small, which is advantageous in reducing the size of the through-hole 121, making it easier to seal subsequent through-holes 121, and improving the structural strength of the first pole column 12.

[0101] Referring again to Figures 12 and 15, exemplary, the spacing direction of the multiple through holes 121 on the first pole column 12 (e.g., the third direction Y shown in Figure 15) is different from the length direction of the through holes 121 (e.g., the second direction X shown in Figure 15). That is, the spacing direction of the multiple through holes 121 on the first pole column 12 is an angle intersecting the length direction of the through holes 121. Thus, the multiple through holes 121 may be arranged at intervals along a direction intersecting the length direction of the through holes 121, thereby reducing the space occupied by the multiple through holes 121 on the first pole column 12 in the length direction of the through holes 121, which is advantageous for reducing the dimensions of the first pole column 12 in the length direction of the through holes 121, and is advantageous for miniaturizing the first pole column 12. For example, the multiple through holes 121 may be spaced apart along the width direction of the through hole 121 (for example, the third direction Y shown in Figure 15), thereby reducing the space occupied by the through holes 121 relative to the first pole column 12, which is advantageous for a smaller design of the first pole column 12.

[0102] Referring again to Figure 15, exemplarily, the length L1 of the through-hole 121 is greater than or equal to the length a of the portion of the connecting portion 222 located within the through-hole 121, and less than or equal to the sum of the length a of the portion of the connecting portion 222 located within the through-hole 121 and 22 mm, i.e., 1.1a ≤ L1 ≤ a + 22 mm. As a result, the width L2 of the through-hole 121 is not too small, allowing the conductive portion 22 to pass through the through-hole 121 smoothly, and the width L2 of the through-hole 121 is not too large, resulting in a relatively small gap between the conductive portion 22 and the through-hole 121 after fitting, which is advantageous for sealing, and is advantageous for improving the structural strength of the first pole column 12, or is advantageous for reducing the dimensions and cost of the first pole column 12 while maintaining equivalent structural strength.

[0103] Specifically, sample cross-sections can be cut from lengths a and L1, and then dimensional measurements can be performed using a two-dimensional projection measuring instrument or a CT scan (i.e., computed tomography).

[0104] Tests have shown that when length a is 20 mm and length L1 is 1.09a, or 21.8 mm, the manufacturing misalignment tolerance of the connection part 222 is 4 mm, and there is a risk of interference with the edge of the through hole 121 during drilling. When length a is 20 mm and length L1 is a + 23 mm, or 43 mm, the dimensions of the first pole column 12 need to be increased, resulting in relatively high material costs and relatively low structural strength of the first pole column 12. When length a is 20 mm and length L1 is approximately 33.8 mm, not only is assembly with the through hole 121 easier, but the dimensions of the first pole column 12 can be reduced, saving material costs and improving the structural strength of the first pole column 12.

[0105] Referring again to Figure 15, in combination with Figure 16, Figure 16 is a local cross-sectional view of a battery cell 10 provided by some embodiments of the present application, wherein the width L2 of the through hole 121 is at least 1.1 times the total thickness b of all the connecting parts 222 located within the through hole 121, and is less than or equal to the sum of the total thickness b of all the connecting parts 222 located within the through hole 121 and 7 mm, i.e., 1.1b ≤ L2 ≤ b + 7 mm. This is advantageous because the width L2 of the through hole 121 is not too small, allowing the conductive part 22 to pass through the through hole 121 smoothly, and because the width L2 of the through hole 121 is not too large, the gap between the conductive part 22 and the through hole 121 after fitting is relatively small, facilitating sealing and improving the structural strength of the first pole column 12, or advantageous in reducing the dimensions and cost of the first pole column 12 with equivalent structural strength.

[0106] Specifically, sample cross-sections can be cut from both length b and length L2, and then dimensional measurements can be performed using a two-dimensional projection measuring instrument or a CT scan (i.e., computed tomography).

[0107] Tests have shown that when length b is 0.6 mm and length L2 is 1.09b, or 0.654 mm, the positional accuracy of the connection part 222 and the through hole 121 is greater than 0.2 mm, creating a risk of interference with the edge of the through hole 121 during drilling. When length b is 0.6 mm and length L2 is b + 7.1 mm, or 7.7 mm, the dimensions of the first pole column 12 need to be increased, resulting in relatively high material costs and relatively low structural strength of the first pole column 12. When length b is 0.6 mm and length L2 is approximately 3 mm, not only is assembly with the through hole 121 easier, but the dimensions of the first pole column 12 can be reduced, saving material costs and improving the structural strength of the first pole column 12.

[0108] Referring again to Figure 8, in some embodiments of the present invention, the first pole column 12 has a housing groove 124 that communicates with a through hole 121, and a portion of the conductive portion 22 penetrates the through hole 121 and is housed in the housing groove 124. As can be understood, the housing groove 124 is a groove body, and the groove body is a groove-shaped structure having a certain depth. In the above technical invention, since the housing groove 124 is installed in the first pole column 12, the weight of the first pole column 12 can be reduced, which is advantageous in improving the gravimetric energy density of the battery cell 10. Furthermore, by housing a portion of the conductive portion 22 in the housing groove 124, the space occupied within the casing 11 is reduced, which is advantageous in increasing the volume of the active material coated portion 21, which is advantageous in improving the volumetric energy density of the battery cell 10.

[0109] Referring again to Figure 8, exemplary, the first pole column 12 comprises an end wall 122 and a side wall 123, the end wall 122 is located on one side of the side wall 123 that is close to the interior of the casing 11, the end wall 122 and the side wall 123 surround each other to form a housing groove 124, the groove opening 1241 of the housing groove 124 opens toward one side away from the interior of the casing 11, that is, the surface of the first pole column 12 on one side away from the interior of the casing 11 is the pole column outer end face 125, the groove opening 1241 of the housing groove 124 penetrates the pole column outer end face 125, the multiple through holes 121 are all opened in the end wall 122 and communicate the housing groove 124 with the interior of the casing 11, the outer end 224 of the conductive part 22 is inserted into the housing groove 124 from the through holes 121 and connected to the end wall 122.

[0110] For example, if the first pole column 12 is installed on the top wall of the casing 11 and the outer end face 125 of the pole column is the upper surface of the first pole column 12, the housing groove 124 is formed as a recessed groove with a groove opening 1241 that opens upward and groove walls that are recessed downward (i.e., recessed in the direction approaching the battery core assembly 2). Alternatively, if the first pole column 12 is installed on the bottom wall of the casing 11 and the outer end face 125 of the pole column is the lower surface of the first pole column 12, the housing groove 124 is formed as a recessed groove with a groove opening 1241 that opens downward and groove walls that are recessed upward (i.e., recessed in the direction approaching the battery core assembly 2).

[0111] In the above proposed technology, the accommodating groove 124 is open toward one side away from the inside of the casing 11 of the first pole column 12. This is advantageous for welding the conductive portion 22 and the end wall 122 through the accommodating groove 124 from the outside of the first pole column 12, that is, from one side away from the active material coated portion 21 of the first pole column 12. In other words, it facilitates external welding of the first pole column 12 and the conductive portion 22 through the accommodating groove 124, facilitating the processing and manufacturing of the battery cell 10 and saving processing and manufacturing costs.

[0112] For example, the accommodating groove 124 may be rectangular, elliptical, or racetrack-shaped, with a cross-sectional length greater than its width. The weld marks formed by welding the conductive portion 22 and the first pole column 12 may be elongated weld marks parallel to the length of the accommodating groove 124, in order to improve welding reliability and increase current flow performance.

[0113] Referring again to Figure 8, in several selectable embodiments of the present invention, the outer ends 224 of the multiple conductive parts 22 connected to the end wall 122 are stacked and connected on the end wall 122, that is, the multiple conductive parts 22 on the end wall 122 are stacked and integrally connected to form an electrical connection with the first pole column 12. By stacking and installing the outer ends 224 of the multiple conductive parts 22 on the end wall 122 in this way, the space occupied by the end wall 122 can be reduced, which is advantageous for the miniaturization design of the first pole column 12.

[0114] Referring again to Figure 16, in another selectable embodiment of the present invention, the outer ends 224 of the multiple conductive parts 22 connected to the end wall 122 are spaced apart on the end wall 122, that is, the multiple conductive parts 22 on the end wall 122 are not stacked and are each connected to the end wall 122 individually to form an electrical connection with the first pole column 12. Thus, since each conductive part 22 is connected to the end wall 122 individually, it is advantageous to improve the reliability of the electrical connection between each conductive part 22 and the first pole column 12.

[0115] Referring again to Figure 8, the casing assembly 1 further comprises a pole column cover plate 13, which fits with the first pole column 12 and seals the groove 1241, and the pole column cover plate 13 is electrically connected to the first pole column 12. In the above technical proposal, by installing the pole column cover plate 13 and sealing the groove 1241 of the housing groove 124, leakage of the electrolyte in the casing 11 from the groove 1241 of the housing groove 124 can be prevented. Furthermore, since the pole column cover plate 13 seals the groove 1241 of the housing groove 124 and is electrically connected to the first pole column 12, an indirect electrical connection between the first pole column 12 and the bus member can be easily realized using the pole column cover plate 13, and it is advantageous to increase the connection area of ​​the electrical connection part, and consequently to reduce the resistance of the electrical connection part.

[0116] It should be explained that, as long as sealing of the groove opening 1241 of the housing groove 124 of the pole column cover plate 13 can be achieved, the fitting method and fitting position of the pole column cover plate 13 and the first pole column 12 are not limited. For example, during processing, the conductive part 22 may first be passed through the through hole 121 and welded to the end wall 122 of the housing groove 124, and then the pole column cover plate 13 may be welded to the first pole column 12 to seal the groove opening 1241 of the housing groove 124. It should also be explained that the specific configuration of the pole column cover plate 13 is not limited, and may be, for example, an integral structure or a composite structure.

[0117] Referring again to Figures 3 to 8 and Figures 11 to 15, the battery cell 10 according to a specific embodiment of the present application will be described.

[0118] The battery cell 10 comprises a casing assembly 1 and a battery core assembly 2. The casing assembly 1 comprises a casing 11, which is provided with one positive electrode column and one negative electrode column, both of which are first electrode columns 12. The battery core assembly 2 is housed in the casing 11 and comprises a plurality of electrode assemblies 20, each electrode assembly 20 comprising an active material coated portion 21 and a conductive portion 22. The conductive portion 22 comprises a convergent portion 221 and a connecting portion 222. The convergent portion 221 is formed by the convergence of a plurality of tab sheets 220, and the connecting portion 222 is Multiple tab sheets 220 converge and connect to form the assembly, with the convergence portion 221 connected to the connection portion 222 and the active material coating portion 21. The connection portion 222 is welded to the first pole column 12 and electrically connected to the first pole column 12. The connection position between the convergence portion 221 and the connection portion 222 is the connection base portion 223. The first pole column 12 is provided with through holes 121 at positions corresponding to the connection base portion 223 of each conductive portion 22 of each electrode assembly 20. The conductive portion 22 is drilled in the through holes 121 corresponding to the connection base portion 223, thereby drilling one conductive portion 22 in each through hole 121.

[0119] Furthermore, the first pole column 12 is provided with an end wall 122 and a side wall 123, the end wall 122 is located on one side of the side wall 123 that is close to the inside of the casing 11, the end wall 122 and the side wall 123 surround each other to form a receiving groove 124, the groove opening 1241 of the receiving groove 124 is open toward one side away from the inside of the casing 11, the multiple through holes 121 are all opened in the end wall 122 and communicate the receiving groove 124 with the inside of the casing 11, each through hole 121 is an elongated hole and the multiple through holes 121 on the end wall 122 are spaced apart along the width direction of the through hole 121. The conductive portion 22 includes a connecting portion 222 drilled in the through hole 121. The length of the portion of the connecting portion 222 located within the through hole 121 coincides with the length of the through hole 121, and the width of the through hole 121 is aligned with the thickness of the connecting portion 222. The connecting portion 222 is inserted into the housing groove 124 from the through hole 121 and welded to the end wall 122. Multiple connecting portions 222 welded to the end wall 122 are stacked and integrally welded to the end wall 122. A pole column cover plate 13 is welded to the groove 1241, and the pole column cover plate 13 seals the groove 1241 and is electrically connected to the first pole column 12.

[0120] In the above proposed technology, each first pole column 12 in the battery cell 10 is drilled and connected to a plurality of conductive parts 22, and each conductive part 22 is equipped with a plurality of tab sheets 220 that are stacked and connected in a converged manner. This reduces the number of tab sheets 220 provided in each conductive part 22, and further reduces the convergence height of the plurality of tab sheets 220 in each conductive part 22. This reduces the space occupied by each conductive part 22 in the direction of tab extension within the casing 11, and if the dimensions of the casing 11 are constant, it improves the space that the active material coated part 21 can occupy in the direction of tab extension, which is advantageous for improving the energy density of the battery cell 10.

[0121] According to several embodiments of the present application, the present application further provides a battery 100 comprising a battery cell 10 of any one of the above embodiments. In the above invention, since the battery cell 10 is installed in the battery 100, the energy density of the battery cell 10 can be improved, which is advantageous in improving the energy density of the battery 100.

[0122] According to some embodiments of the present application, the present application further provides an electrical device 1000 including the battery 100 of the above embodiment, the battery 100 being used to supply electrical energy to the electrical device 1000. In the above technical invention, since the battery 100 is installed in the electrical device 1000, the energy density of the battery 100 can be improved, which is advantageous in improving the operating time of the electrical device 1000. If the electrical device 1000 is a vehicle, it should be understood that the improved operating time of the battery 100 is advantageous in extending the driving range of the vehicle.

[0123] The embodiments and features of the embodiments of this application can be combined with each other, as long as there are no contradictions.

[0124] The foregoing describes only preferred embodiments of the present application and does not limit it, and various modifications and changes are possible for those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and principles of the present application should be included within the scope of the claims.

Claims

1. It is a battery cell, A casing assembly comprising a casing and a first pole post installed in the casing, wherein the first pole post is an electrode terminal of the battery cell, A battery core assembly comprising a conductive portion housed in the casing and electrically connected to the first pole column, wherein the conductive portion comprises a plurality of tab sheets stacked and connected in a converged manner, In this configuration, a plurality of conductive parts are directly electrically connected to the first pole column, and the first pole column has a plurality of through holes, with at least one conductive part drilled in each of the through holes. Battery cell.

2. The battery core assembly comprises at least one electrode assembly, each of which comprises the conductive portion, and the through-holes are provided at positions corresponding to each of the electrode assemblies on the first pole. The battery cell according to claim 1.

3. The electrode assembly comprises an active material coated portion, the conductive portion comprises a convergent portion and a connecting portion, the convergent portion is formed by the convergence of a plurality of tab sheets, the connecting portion is formed by the convergence and connection of a plurality of tab sheets, and is used for electrical connection to the first electrode column, the convergent portion connects the connecting portion and the active material coated portion, the connection position between the convergent portion and the connecting portion is the connection base portion, and the first electrode column is provided with the through hole at a position corresponding to at least one of the connection base portions of each electrode assembly. The battery cell according to claim 2.

4. The through holes are provided at positions corresponding to the connection base of each conductive part on the first pole column. The battery cell according to claim 3.

5. The first pole column is provided with the through-holes corresponding to the intermediate region in the thickness direction of each electrode assembly. The battery cell according to claim 2.

6. The electrode assembly comprises an active material coated portion, the conductive portion comprises a convergent portion and a connecting portion, the convergent portion is formed by the convergence of a plurality of tab sheets, the connecting portion is formed by the convergence and connection of a plurality of tab sheets, and is used to electrically connect to the first electrode post, the convergent portion connects the connecting portion and the active material coated portion, the connection position between the convergent portion and the connecting portion is a connection base portion, and at least one of the connection base portions of the electrode assembly corresponds to an intermediate region in the thickness direction of the electrode assembly. The battery cell according to claim 2.

7. The through holes are provided at positions corresponding to the connection base of each conductive part on the first pole column. The battery cell according to claim 6.

8. The battery core assembly comprises at least one combination, each combination comprising two electrode assemblies, each electrode assembly in each combination comprising a plurality of conductive parts of the same polarity, and at least two conductive parts of the same polarity belonging to different electrode assemblies and arranged adjacently in each combination are connected and installed. The battery cell according to claim 2.

9. The battery core assembly comprises at least one electrode assembly, each electrode assembly comprising at least one conductive portion, the electrode assembly comprising an active material coated portion, the conductive portion comprising a convergent portion and a connecting portion, the convergent portion being formed by the convergence of a plurality of tab sheets, the connecting portion being formed by the convergence and connection of a plurality of tab sheets, and used for electrical connection to the first electrode post, the convergent portion connecting the connecting portion and the active material coated portion, the connection position between the convergent portion and the connecting portion being a connection base, and the conductive portion being drilled in one of the through holes closest to the corresponding connection base. The battery cell according to claim 1.

10. The through holes are provided at positions corresponding to the connection base of each conductive part on the first pole column. The battery cell according to claim 9.

11. The through-hole is an elongated hole, the conductive portion comprises a connecting portion drilled in the through-hole, the connecting portion is sheet-like and the length direction of the portion located within the through-hole coincides with the length direction of the through-hole, and the width direction of the through-hole coincides with the thickness direction of the connecting portion. The battery cell according to claim 1.

12. The spacing direction of the plurality of through holes in the first pole column is different from the length direction of the through holes. The battery cell according to claim 11.

13. The first pole column has a housing groove that communicates with the through hole, and a part of the conductive part is housed in the housing groove after passing through the through hole. The battery cell according to claim 1.

14. The first pole column comprises an end wall and a side wall, the end wall being located on one side of the side wall adjacent to the interior of the casing, the end wall and the side wall surrounding each other to form the housing groove, the opening of the housing groove being open toward one side away from the interior of the casing, the plurality of through holes all being opened in the end wall to connect the housing groove to the interior of the casing, and the outer end of the conductive part being inserted into the housing groove through the through hole and connected to the end wall. The battery cell according to claim 13.

15. The outer ends of the multiple conductive parts connected to the end wall are stacked and connected to the end wall, or the outer ends of the multiple conductive parts connected to the end wall are installed on the end wall at intervals. The battery cell according to claim 14.

16. The casing assembly further comprises a pole post cover plate, the pole post cover plate engages with the first pole post and seals the groove, and the pole post cover plate is electrically connected to the first pole post. The battery cell according to claim 14.

17. The casing is provided with a plurality of pole columns, and at least one of these pole columns is the first pole column. The battery cell according to claim 1.

18. A battery cell according to any one of claims 1 to 17, battery.

19. A battery including the one described in claim 18, Electrical device.

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