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 This application is filed based on a Chinese patent application bearing application number 202321139017.6 and filed on May 11, 2023, and claims priority to the above-mentioned Chinese patent application, the entire contents of which are incorporated herein by reference.

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

[0003] In recent years, new energy vehicles have made great strides, and in the field of electric vehicles, batteries play an irreplaceable and important role as the power source for electric vehicles. Batteries typically contain multiple battery cells, and currently, it is difficult to improve the energy density of battery cells, making it difficult to extend the vehicle's driving range. Summary of the Invention

[0004] Embodiments of the present application provide battery cells, batteries, and electrical devices that are advantageous for improving the energy density of battery cells.

[0005] In a first aspect, an embodiment of the present application provides a battery cell, the battery cell comprising: a casing assembly and a battery core assembly; the casing assembly comprising a casing and a first pole mounted in the casing; the battery core assembly comprising a conductive part housed in the casing and electrically connected to the first pole; the conductive part comprising a plurality of tab sheets arranged in a stacked manner and connected to each other in a converging manner; the plurality of conductive parts electrically connected to the first pole; and the first pole having a plurality of through holes, each of which has at least one conductive part drilled therein.

[0006] In the above technical solution, multiple conductive parts are electrically connected to the first pole, and therefore the battery cell has multiple conductive parts of the same polarity. Each conductive part has multiple tab sheets that are stacked and connected to each other in a convergent manner. This reduces the number of tab sheets in each conductive part, and also reduces the convergence height of the multiple tab sheets in each conductive part. This reduces the size that each conductive part occupies in the casing along the tab extension direction. When the casing size is constant, this increases the occupyable space of the active material application part in the tab extension direction, which is advantageous for improving the energy density of the battery cell. Furthermore, the first pole is configured to have a plurality of conductive parts electrically connected thereto, and the first pole has a plurality of through holes, each of which has at least one conductive part drilled therein. This allows all of the conductive parts electrically connected to the first pole to be at least partially housed within the first pole and occupy space in the first pole, thereby further reducing the space occupied by the conductive parts within the casing. Compared to a solution in which all of the conductive parts electrically connected to the first pole are passed through a single through hole in a concentrated manner, the present invention has the advantage of reducing the size of each through hole, thereby improving the adverse effect on the structural strength of the first pole caused by the relatively large size of the through hole. In addition, by providing multiple through holes, the conductive part can have more flexibility in selecting the through holes. For example, when the distances between the multiple through holes and the conductive part are different, the conductive part can select a relatively closer through hole to extend from, 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. Furthermore, for example, the conductive part can select a relatively smaller number of through holes to drill the conductive part to extend from, which facilitates assembly and solves the problem that the dimensions of some of the through holes are relatively large, thereby improving the structural strength of the first pole.

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

[0008] In the above technical solution, the conductive parts extending from the electrode assemblies can pass through the through-holes provided corresponding to the electrode assemblies, thereby effectively shortening the extension length of the conductive parts within the casing and reducing the space occupied by the conductive parts within the casing, which is advantageous for improving the energy density of the battery cell. Alternatively, some conductive parts may be selected to pass through the through-holes provided corresponding to adjacent electrode assemblies depending on the situation, thereby improving manufacturing flexibility.

[0009] In some embodiments, the electrode assembly includes an active material application portion, the conductive portion includes a converging portion and a connecting portion, the converging portion is formed by converging a plurality of tab sheets, the connecting portion is formed by converging and connecting a plurality of tab sheets, the connecting portion is used for electrical connection with the first electrode post, the converging portion connects the connecting portion and the active material application portion, the connection position between the converging portion and the connecting portion is a connection root portion, and the first electrode post has a through hole at a position corresponding to the connection root portion of at least one of the electrode assemblies.

[0010] In the above technical solution, at least one conductive part can pass through a through hole corresponding to its connection root part, thereby shortening the extension length of the connection part of the conductive part within the casing, reducing the space occupied by the conductive part within the casing, and advantageously improving the energy density of the battery cell.

[0011] In some embodiments, the first electrode posts are provided with through holes corresponding to intermediate regions in the thickness direction of the electrode assemblies.

[0012] In the above technical solution, by locating the through hole close to or approximately close to the center of the electrode assembly, no matter where or how many conductive parts on the electrode assembly extend, they can all be relatively close to the centrally located through hole, thereby preventing the conductive parts from extending too far before passing through the through hole, and further reducing the space occupied by each conductive part in the casing.

[0013] In some embodiments, the electrode assembly includes an active material application portion, the conductive portion includes a converging portion and a connecting portion, the converging portion is formed by converging a plurality of tab sheets, the connecting portion is formed by converging and connecting a plurality of tab sheets, the connecting portion is used to electrically connect with the first electrode post, the converging portion connects the connecting portion and the active material application portion, the connection position between the converging portion and the connecting portion is a connecting root portion, and at least one connecting root portion of the electrode assembly corresponds to an intermediate region in the thickness direction of the electrode assembly.

[0014] In the above technical solution, the tab sheet of at least one conductive part of the electrode assembly can be converged toward the center or approximately toward the center, thereby reducing the convergence height of the conductive part and thereby reducing the dimension of the conductive part in the casing along the extension direction of the tab, which is advantageous for improving the energy density of the battery cell. Furthermore, the distances between the centrally converged conductive part and each through-hole corresponding to the corresponding electrode assembly can be relatively close, so that the conductive part does not extend too far before passing through the through-hole, and further reducing the space occupied by each conductive part in the casing.

[0015] In some embodiments, the battery core assembly includes at least one combination, each combination including two electrode assemblies, each electrode assembly in each combination including a plurality of same-polarity conductive portions, and at least two same-polarity conductive portions that belong to different electrode assemblies and are arranged adjacent to each other in each combination are connected and installed.

[0016] In the above technical solution, 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 being too large, ensuring the structural strength of the first electrode post, and advantageously reducing the space occupied by the conductive parts in the casing in the extending direction of the tabs.

[0017] In some embodiments, the battery core assembly includes at least one electrode assembly, each electrode assembly including at least one conductive portion, the electrode assembly including an active material application portion, the conductive portion including a converging portion and a connecting portion, the converging portion being formed by converging a plurality of tab sheets, the connecting portion being formed by converging and connecting a plurality of tab sheets, the connecting portion being used for electrical connection with the first electrode post, the converging portion connecting the connecting portion and the active material application portion, the connection position between the converging portion and the connecting portion being a connection root portion, and the conductive portion being drilled in one through-hole closest to the corresponding connection root portion.

[0018] In the above technical solution, by drilling each conductive part into the through hole nearest to its connection root part, the conductive part selects a relatively closer through hole to extend through, which is advantageous to shorten the extension length of the conductive part within the casing before passing through the through hole, reducing the space occupied by the conductive part within the casing and improving the energy density of the battery cell, and is advantageous to reducing the redundancy of the conductive part within the casing, which effectively reduces the redundancy of the conductive part within the casing and the risk of forming a short circuit with the active material coating part, and improves the reliability of the battery cell.

[0019] In some embodiments, through holes are provided at positions corresponding to the connection root portions of the conductive portions on the first pole.

[0020] In the above technical solution, each conductive part can pass through a through-hole corresponding to its connection root, 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 beneficial to further improving the energy density of the battery cell, and also reducing the redundancy of each conductive part within the casing, which more effectively reduces the redundancy of the conductive parts within the casing and the risk of short-circuiting with the active material coating part, which is beneficial to improving the reliability of the battery cell.

[0021] In some embodiments, the through hole is an elongated hole, the conductive portion has a connection portion drilled in the through hole, the connection portion is sheet-shaped, 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 connection portion.

[0022] In the above technical solution, the through hole is arranged in an elongated shape that approximately matches the shape of the connection part of the conductive part, so that the connection part of the conductive part can easily pass through the through hole, and after the conductive part passes through the through hole, the space left in the through hole can be relatively small, thereby reducing the size of the through hole, making it easier to seal the subsequent through hole location, and is advantageous to improving the structural strength of the first pole.

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

[0024] In the above technical solution, the multiple through holes on the first pole can be arranged at intervals along a direction intersecting the length of the through holes, thereby reducing the space occupied by the multiple through holes relative to the first pole in the length direction of the through holes, which is advantageous for reducing the dimension of the first pole in the length 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, or the conductive portion further includes an adapter sheet, and the tab sheets are connected to the first pole via the adapter sheet.

[0026] In the above technical solution, if the conductive part is composed of multiple tab sheets and the tab sheets are welded to the first terminal post, the structure and processing of the conductive part can be simplified. If the conductive part further includes an adapter sheet and the tab sheet is connected to the first terminal post via the adapter sheet, the adapter sheet can be welded to the first terminal post while avoiding the portion connected to the tab sheet, which makes the weld between the adapter sheet and the first terminal post strong and reduces the risk of weld cracking.

[0027] In some embodiments, the first pole has an accommodating groove communicating with the through hole, and a portion of the conductive portion passes through the through hole and is accommodated in the accommodating groove.

[0028] In the above technical solution, since the accommodating groove is installed in the first pole, the weight of the first pole can be reduced, which is advantageous to improving the weight energy density of the battery cell; and by accommodating a portion of the conductive part in the accommodating groove, the space occupied by the conductive part in the casing can be reduced, which is advantageous to increasing the volume of the active material application part, which is advantageous to improving the volume energy density of the battery cell.

[0029] In some embodiments, the first pole has an end wall and a side wall, the end wall is located on one side of the side wall close to the inside of the casing, the end wall and the side wall surround each other to form an accommodating groove, the groove opening toward one side away from the inside of the casing, a plurality of through holes are opened in the end wall to connect the accommodating groove to the inside of the casing, and the outer end of the conductive part is inserted into the accommodating groove through the through hole and connected to the end wall.

[0030] In the above technical solution, the receiving groove is open toward one side of the first pole that is away from the inside of the casing. This makes it possible to weld the conductive part and the end wall through the receiving groove from the outside of the first pole, i.e., from the side of the first pole that is away from the active material coating portion. In other words, it is advantageous to externally weld the first pole and the conductive part through the receiving groove, which facilitates the processing and manufacturing of the battery cell and reduces processing and manufacturing costs.

[0031] In some embodiments, the outer ends of the multiple conductive portions connected to the end wall are stacked and connected on the end wall, or the outer ends of the multiple conductive portions connected to the end wall are spaced apart on the end wall.

[0032] In the above technical solution, if the outer ends of the plurality of conductive parts connected to the end wall are stacked and connected to the end wall, it is advantageous for miniaturizing the design of the first pole. If the outer ends of the plurality of conductive parts connected to the end wall are spaced apart from the end wall, it is advantageous for improving the reliability of the electrical connection between each conductive part and the first pole.

[0033] In some embodiments, the casing assembly further comprises a pole cover plate, the pole cover plate being fitted with the first pole and sealingly capping the groove opening, the pole cover plate being electrically connected to the first pole.

[0034] In the above technical solution, by installing a pole cover plate to seal the groove opening of the accommodating groove, it is possible to prevent the electrolyte in the casing from leaking from the groove opening of the accommodating groove. Furthermore, since the pole cover plate seals the groove opening of the accommodating groove and is electrically connected to the first pole, it is possible to easily realize an indirect electrical connection between the first pole and the bus member by using the pole cover plate, which is advantageous in increasing the connection area of ​​the electrical connection part and therefore advantageous in reducing the resistance of the electrical connection part.

[0035] In some embodiments, the casing is provided with a plurality of poles, at least one of which is the first pole.

[0036] In the above technical solution, by setting at least one of all the poles of the casing assembly as a first pole, some of the entire battery cells may be first poles with multiple through holes, or all of the battery cells may be first poles with multiple through holes, which allows for flexible selection and combination according to manufacturing needs, cost needs, etc.

[0037] In a second aspect, embodiments of the present application further provide a battery comprising the battery cell described above.

[0038] In the above technical solution, the above battery cells are installed in the battery, which can improve the energy density of the battery cells, and is therefore advantageous to improving the energy density of the battery.

[0039] In a third aspect, embodiments of the present application further provide an electrical device comprising the battery described above.

[0040] In the above technical solution, the battery is installed in the electrical device, which can improve the energy density of the battery, and is therefore advantageous to improving the service life of the electrical device.

[0041] In order to more clearly explain the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings used in the embodiments. However, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope. Those skilled in the art can obtain other related drawings based on these drawings without any creative work. [Brief explanation of the drawings]

[0042] [Figure 1] 1 is a structural schematic diagram of an electric device, which is a vehicle, provided by some embodiments of the present application. [Figure 2] 1 is an exploded view of a battery cell used in a battery provided in accordance with some embodiments of the present application. FIG. [Figure 3] 1 is a perspective view of a battery cell provided in accordance with some embodiments of the present application. [Figure 4] FIG. 4 is an exploded view of a partial configuration of the battery cell shown in FIG. 3. [Figure 5] FIG. 5 is a local enlarged view of a portion A shown in FIG. 4. [Figure 6] FIG. 4 is an orthographic view of the battery cell shown in FIG. 3. [Figure 7] FIG. 7 is a cross-sectional view taken along line BB in FIG. [Figure 8] FIG. 8 is an enlarged view of a portion C shown in FIG. 7. [Figure 9]1 is a partial cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 10] 1 is a partial cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 11] 1 is a perspective view of a first pole provided in accordance with some embodiments of the present application. FIG. [Figure 12] FIG. 12 is an orthographic view of the first polar pillar shown in FIG. 11. [Figure 13] FIG. 13 is a cross-sectional view taken along line DD in FIG. [Figure 14] FIG. 1 is an orthographic view of a battery cell provided in accordance with some embodiments of the present application. [Figure 15] FIG. 15 is a local enlarged view of a portion E shown in FIG. [Figure 16] 1 is a partial cross-sectional view of a battery cell provided in accordance with 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 12, through hole 121, end wall 122, side wall 123, accommodating groove 124, groove opening 1241, pole outer end surface 125, pole cover plate 13, battery core assembly 2, electrode assembly 20, intermediate region 201, active material application portion 21, conductive portion 22, tab sheet 220, converging portion 221, connection portion 222, connection root portion 223, outer end portion 224 of conductive portion, adapter sheet 225, first direction Z, second direction X, third direction Y. DETAILED DESCRIPTION OF THE INVENTION

[0044] In order to clarify the objectives, technical solutions and advantages of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application, but it is obvious that the described embodiments are only some of the embodiments of the present application, and do not represent all of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without performing creative work fall within the scope of protection of the present application.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art of this application, and the terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit this application, and the terms "comprises" and "has" and any variations thereof in the specification, claims, and drawings of this application are intended to cover a non-exclusive inclusion. Terms such as "first," "second," etc. in the specification, claims, and drawings of this application are used to distinguish between different objects and are not used to describe a particular order or priority.

[0046] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearances of the phrase in various locations in the specification do not necessarily refer to the same embodiment, nor are they mutually exclusive independent or alternative embodiments of other embodiments.

[0047] The term "and / or" in this application is simply a relational relationship that describes related objects, and indicates that three types of relationships can exist. For example, A and / or B can represent three situations: the presence of only A, the simultaneous presence of A and B, and the presence of only B. In addition, the symbol " / " in this application generally indicates that the related objects before and after it are in an "or" relationship.

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

[0049] The term "plurality" as used herein refers to two or more (including two).

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

[0051] For example, a battery cell may generally include 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 poles, which generally include a plurality of poles, each pole including at least one positive pole and at least one negative pole. The battery core assembly includes one or more electrode assemblies, which are formed by stacking or winding positive and negative pole pieces and separator films.

[0052] The positive electrode piece generally includes a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer being directly or indirectly coated on the positive electrode current collector, the portion of the positive electrode current collector not coated with the positive electrode active material layer protruding from the portion of the positive electrode current collector coated with the positive electrode active material layer, the portion of the positive electrode current collector not coated with the positive electrode active material layer being a positive electrode tab sheet, and multiple positive electrode tab sheets are stacked and electrically connected to the positive electrode post. For example, multiple stacked positive electrode tab sheets can be directly welded to the positive electrode post to form the electrical connection, or the battery core assembly can include a positive electrode adapter sheet, and the multiple stacked positive electrode tab sheets can be welded to one end of the positive electrode adapter sheet and the other end of the positive electrode adapter sheet to electrically connect the positive electrode tab sheet and the positive electrode post.

[0053] The negative electrode piece generally includes a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer being directly or indirectly coated on the negative electrode current collector, the negative electrode current collector not coated with the negative electrode active material layer protruding from the negative electrode current collector coated with the negative electrode active material layer, and the positive electrode current collector not coated with the negative electrode active material layer being used as a negative electrode tab sheet, and multiple negative electrode tab sheets are stacked together and electrically connected to the negative electrode post. For example, the multiple stacked negative electrode tab sheets can be directly welded to the negative electrode post to form the electrical connection, or the battery core assembly can include a negative electrode adapter sheet, and the multiple stacked negative electrode tab sheets can be welded to one end of the negative electrode adapter sheet and the other end of the negative electrode adapter sheet to electrically connect the negative electrode tab sheet and the negative electrode post.

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

[0055] At the same time, battery cells primarily rely on the movement of metal ions between the positive and negative electrodes to function. Taking lithium-ion batteries as an example, the positive electrode current collector can be made of aluminum, the positive electrode active material layer can be made of lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc., the negative electrode current collector can be made of copper, and the negative electrode active material layer can be made of carbon or silicon. During charging and discharging, Li+ ions are repeatedly inserted and extracted between the two electrodes. During charging, Li+ ions are extracted from the positive electrode and inserted into the negative electrode through the electrolyte, leaving the negative electrode in a lithium-rich state, and vice versa during discharging.

[0056] The battery referred to in the embodiments of this application refers to a single physical module containing one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may be a battery module or a battery pack. A battery module generally includes multiple battery cells. A battery pack generally includes a case for enclosing one or more battery cells or one or more battery modules. The case can prevent liquids or other foreign objects 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, and a series-parallel connection refers to both series and parallel connections among multiple battery cells. Multiple battery cells can also be directly connected in series, parallel, or series-parallel, and the entire battery cell set can be housed in a case. Alternatively, the battery can be in the form of a battery module in which multiple battery cells are first connected in series, parallel, or series-parallel to form multiple battery modules, which are then further connected in series, parallel, or series-parallel to form an integrated battery module and housed in a case.

[0058] In the manufacturing process of a battery cell in the related art, an active material is applied to a current collector, which is then cut to obtain pole pieces consisting of a current collector coated with an active material layer (referred to as an active material-coated portion) and a current collector not coated with an active material layer (referred to as a tab sheet). Positive and negative electrode pieces and a separator film are then stacked or wound in this order to obtain an electrode assembly. The active material-coated portion of the electrode assembly is welded to the electrode post via a conductive portion, which may be a tab portion formed by stacking and winding tab sheets of the same polarity in the electrode assembly to connect them, or may be composed of both the tab portion and an adapter sheet welded to the tab portion.

[0059] Typically, a battery cell casing contains multiple electrode assemblies, and when processing the tab section, all tab sheets of the multiple electrode assemblies with the same polarity are stacked together. This results in a relatively large number of tab sheets in the tab section, and a relatively large convergent height of the tab section formed by the convergent connection (the convergent height refers to the vertical distance from the start point of the convergent connection of the tab sheets to the active material-coated portion, and this vertical distance is referred to as the tab extension direction). As a result, the dimension that the tab section occupies in the tab extension direction within the casing is relatively large. If the casing dimensions are constant, this affects the space that the active material-coated portion can occupy in the tab extension direction, 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 sheets of the pole pieces farthest from the start point of the convergent connection (i.e., the edge tab sheets) is, 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 application proposes a battery cell design in which the number of conductive parts of the same polarity in the battery cell is set to multiple, and each conductive part has multiple tab sheets that are stacked and connected in a converging manner, thereby reducing the number of tab sheets in each conductive part and further reducing the converging height of the tab parts in each conductive part, thereby reducing the size occupied by each conductive part in the casing along the tab extension direction. For a given casing size, this increases the space occupied by the active material coated part in the tab extension direction, which is advantageous for improving the energy density of the battery cell. The pole pieces also reduce deformation of the tab sheets at the edge positions of the conductive parts to a certain extent, reducing the risk of tab sheet cracking.

[0061] In addition, in the embodiments of the present application, at least one electrode post is further provided with a plurality of through holes, and at least one conductive part electrically connected to the electrode post is drilled in each through hole, so that the electrode post can accommodate at least a portion of the conductive part, further reducing the space occupied by the conductive part within the casing, further increasing the space available for the active material coated part within the casing, and further improving the energy density of the battery cell. Furthermore, by providing a plurality of through holes, the conductive part can flexibly select a through hole. For example, if the distances between a plurality of through holes and the conductive part are different, the conductive part can select a relatively close through hole to extend from, which is advantageous for shortening the extension length of the conductive part within the casing and further reducing the space occupied by the conductive part within the casing. For example, the conductive part can select to extend through a through hole with a relatively small number of conductive parts, which facilitates assembly, alleviates the problem of some through holes being relatively large, and improves the strength of the electrode post.

[0062] An embodiment of the present application provides an electric device that uses the battery of the present application as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, an electric scooter, an electric vehicle, a boat, a spacecraft, etc. Among them, the electric toy may include a stationary or mobile electric toy, such as a game console, an electric toy vehicle, an electric toy boat, and an electric toy airplane, and the spacecraft may include an airplane, a rocket, a space shuttle, a spaceship, etc.

[0063] For convenience of explanation, in the following embodiments, the electric device is a vehicle, and the structures of the electric device, battery, and battery cell of the present application will be described in detail.

[0064] Referring to FIG. 1, FIG. 1 is a structural schematic diagram of an electric device 1000, which is a vehicle provided by some embodiments of the present application. The vehicle may be a fuel-powered vehicle, a gas-powered vehicle, or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle, a range-extended vehicle, etc. A battery 100 is installed in the vehicle, and the battery 100 may be installed at the bottom, head, or tail of the vehicle. The battery 100 is used to supply power to the vehicle. For example, the battery 100 can function as an operating power source for the vehicle. The vehicle may further include a controller 200 and a motor 300. The controller 200 controls the battery 100 to supply power to the motor 300, for example, to meet the operating power needs for starting, navigating, and driving the vehicle. In some embodiments of the present application, the battery 100 can be used not only as an operating power source for the vehicle but also as a driving power source for the vehicle, thereby providing driving power to the vehicle in place of or partially replacing fuel or natural gas.

[0065] Referring to FIG. 2, FIG. 2 is an exploded view of a structure in which battery cells 10 provided in some embodiments of the present application are used in a battery 100. The battery 100 includes a case 20 and a plurality of battery cells 10, which are housed in the case 20. The case 20 provides an assembly space for the battery cells 10, and the case 20 can have various structures. In some embodiments, the case 20 can include a first case 201 and a second case 202, which cover each other and together define the assembly space for housing the battery cells 10. The second case 202 can have a hollow structure with one end open, and the first case 201 can have 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 define the assembly space. Alternatively, the first case 201 and the second case 202 may both be hollow structures with one side open (for example, as shown in FIG. 2), with the open side of the first case 201 covering the open side of the second case 202. Of course, 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, Figure 3 is a schematic diagram of a battery cell 10 provided according to some embodiments of the present application. The battery cell 10 has a rectangular parallelepiped shape, and the width direction of the battery cell 10 is a first direction Z, the length direction of the battery cell 10 is a second direction X, and the thickness direction of the battery cell 10 is a third direction Y. The first direction Z, the second direction X, and the third direction Y are perpendicular to each other two by two. However, this is not limited thereto, and in other embodiments of the present application, the battery cell 10 may have other shapes, such as a cylindrical, flat, or prismatic structure.

[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 the present application, the battery cell 10 includes a casing assembly 1 and a battery core assembly 2. The casing assembly 1 includes a casing 11 and a first pole 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 the present 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 all embodiments of the present application, the casing 11 will be described as prismatic.

[0068] The casing 11 is provided with poles for electrical connection with the battery core assembly 2 to ensure normal charging and discharging of the battery cells 10. Generally, there are at least two poles, specifically, at least one positive pole and one negative pole. For example, if there are two poles, one is a positive pole and the other is a negative pole, which are electrically connected to the positive and negative output positions of the battery core assembly 2, respectively. Alternatively, if there are four poles, two may be positive poles and the remaining two may be negative poles, with the two positive poles both electrically connected to the positive output positions of the battery core assembly 2 and the two negative poles both electrically connected to the negative output positions of the battery core assembly 2.

[0069] In the embodiment of the present application, at least one of the poles on the casing 11 is a first pole 12, and the first pole 12 may be a positive pole or a negative pole. 5 to 8, FIG. 5 is a local enlarged view of portion A shown in FIG. 4, FIG. 6 is an orthographic view of the battery cell 10 shown in FIG. 3, FIG. 7 is a cross-sectional view taken along line B-B in FIG. 6, and FIG. 8 is a local enlarged view of portion C shown in FIG. 7. The battery core assembly 2 includes conductive portions 22, and each of the first poles 12 is electrically connected to a plurality of conductive portions 22. The first poles 12 have a plurality of through-holes 121, and at least one conductive portion 22 is provided in each through-hole 121. As a result, the plurality of conductive portions 22 electrically connected to the first poles 12 are all at least partially housed in the first poles 12 and occupy space within the first poles 12, which is advantageous for saving the space occupied by the conductive portions 22 within the casing 11 and for improving the energy density of the battery cell 10.

[0070] When a plurality of poles are provided on the casing 11, all of the poles on the casing 11 may be first poles 12 electrically connected to a plurality of conductive parts 22, or some of the poles on the casing 11 may be first poles 12 electrically connected to a plurality of conductive parts 22, and if some of the poles on the casing 11 are first poles 12 electrically connected to a plurality of conductive parts 22, the remaining poles on the casing 11 are second poles (not shown) electrically connected to one conductive part 22. 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 processes of the battery cells 10 are performed normally. For the sake of simplicity, the following description will be given mainly as an example in which the casing 11 has multiple poles, and all of the poles are first poles 12, i.e., multiple conductive parts 22 are electrically connected to each pole.

[0071] In the embodiment of the present application, the battery core assembly 2 includes an active material-coated portion 21, which is housed in the casing 11. The active material-coated portion 21 is a portion of the battery core assembly 2 to which active material is applied and can assist in the detachment 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 pole, which is not coated with active material. Whether it is the first pole 12 or the second pole, both can be electrically connected to the active material-coated portion 21 via the conductive portion 22 so that the charging and discharging of the battery cell 10 can be performed.

[0072] As will be understood, the active material-coated portion 21 is divided into a positive electrode active material-coated portion and a negative electrode active material-coated portion, the positive electrode active material-coated portion including a portion where a positive electrode active material layer is coated on a positive electrode current collector, and the negative electrode active material-coated portion including a portion where a negative electrode active material layer is coated on a negative electrode current collector. The conductive portion 22 is divided into a positive electrode conductive portion and a negative electrode conductive portion, the positive electrode conductive portion electrically connecting the positive electrode active material-coated portion and the positive electrode pole, and the negative electrode conductive portion electrically connecting the negative electrode active material-coated portion and the negative electrode pole.

[0073] 5 and 8 again, in the embodiment of the present application, the conductive portion 22 includes a plurality of tab sheets 220 that are stacked and arranged and converge to be connected, specifically, the conductive portion 22 includes a converging portion 221 and a connecting portion 222, the converging portion 221 is formed by the converging of the plurality of tab sheets 220, the connecting portion 222 is formed by the converging and connecting of the plurality of tab sheets 220, and the converging portion 221 connects the connecting portion 222 to the active material coated portion 21. In other words, when forming the converging portion 221, the plurality of tab sheets 220 simply converge (i.e., converge in a direction toward each other) but are not connected, but when forming the connecting portion 222, the plurality of tab sheets 220 not only converge but also connect to form an integrated structure. For example, multiple tab sheets 220 can be connected to form an integral plate-like structure by welding (e.g., ultrasonic welding) to form a connection portion 222, or multiple tab sheets 220 can be collected and connected by a method such as bonding with a conductive adhesive to form a connection portion 222.

[0074] The connecting portion 222 is used to electrically connect with the first pole 12, that is, the connecting portion 222 may be directly connected with the first pole 12 (for example, as shown in FIG. 8) or indirectly connected thereto (for example, as shown in FIG. 9, which is a local cross-sectional view of a battery cell provided according to some embodiments of the present application). In some alternative embodiments, for example, as shown in FIG. 8, the conductive portion 22 may be composed only of a plurality of tab sheets 220, and in this 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 another alternative embodiment, as shown in FIG. 9 , the conductive portion 22 may further include an adapter sheet 225 in addition to the plurality of tab sheets 220, and the tab sheets 220 are connected to the first pole 12 via the adapter sheet 225. For example, one end of the adapter sheet 225 is welded to the connection portion 222, and the other end of the adapter sheet 225 is welded to the first pole 12, so that the plurality of tab sheets 220 are connected to the first pole 12 via the adapter sheet 225. At this time, the adapter sheet 225 may be welded to the first pole 12 while avoiding the portion connected to the tab sheet 220, so that the welding between the adapter sheet 222 and the first pole 12 is strong and the problem of weld cracking is unlikely to occur.

[0075] As can be seen, 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 stacked together and ultrasonically tack-welded to form a positive electrode connection portion 222, thereby reducing interlayer gaps and forming a plate-like structure with a certain rigidity from the multiple puffed positive electrode tab sheets 220. Similarly, the negative electrode tab sheets 220 that need to converge are stacked together and ultrasonically tack-welded to form a negative electrode connection portion 222, thereby reducing interlayer gaps and forming a plate-like structure with a certain rigidity from the multiple puffed negative electrode tab sheets 220. For example, the current collector and the tab sheet 220 may be an integral member, such as an aluminum foil integrally molded with the positive electrode piece, or a copper foil integrally molded with the negative electrode piece.

[0076] Referring again to Figure 8, the connection position between the converging portion 221 and the connecting portion 222 is the connection root portion 223, the vertical distance from the connection root portion 223 to the active material applied portion 21 is the convergence height (for example, the distance H shown in Figure 8), and the direction of this vertical distance is referred to as the extension direction of the tab (for example, the first direction Z shown in Figure 8). In the embodiment of the present application, each first electrode post 12 is electrically connected to a plurality of conductive portions 22, i.e., the number of conductive portions 22 of the same polarity in the battery cell 10 is plural. That is, all of the positive electrode tab sheets 220 in the battery cell 10 converge and connect to form a plurality of positive electrode connection portions 222, and all of the negative electrode tab sheets 220 in the battery cell 10 converge and connect to form a plurality of negative electrode connection portions 222. Each conductive portion 22 has a plurality of tab sheets 220 that are stacked and convergently connected. This reduces the number of tab sheets 220 in each conductive portion 22 and the convergence height of the multiple tab sheets 220 in each conductive portion 22. This reduces the dimension that each conductive portion 22 occupies in the tab extension direction within the casing 11. When the dimension of the casing 11 is constant, this increases the space that the active material-coated portions 21 can occupy in the tab extension direction, which is advantageous for improving the energy density of the battery cell 10. Furthermore, the number of tab sheets 220 provided for each conductive portion 22 is relatively small, which reduces deformation of the tab sheets 220 at the edge positions of the conductive portion 22 to some extent and reduces the risk of the tab sheets 220 cracking.

[0077] Furthermore, in the embodiment of the present application, the number of through holes 121 on the first pole 12 is multiple, and at least one conductive part 22 is drilled in each through hole 121. Compared to the idea of ​​concentrating all the conductive parts 22 electrically connected to the first pole 12 through one through hole 121, the embodiment of the present application has the advantage of reducing the size of each through hole 121, thereby improving the adverse effect on the structural strength of the first pole 12 caused by the relatively large size of the through holes 121. In addition, by providing multiple through holes 121, the conductive part 22 can have more flexibility in selecting 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 can select a relatively close through hole 121 to extend from, which is advantageous in shortening the extension length of the conductive part 22 and further reducing the space occupied by the conductive part 22 within the casing 11. Also, for example, the conductive part 22 can select a relatively small number of through holes 121 to extend from, which makes assembly easier and solves the problem that the dimensions of some of the through holes 121 are relatively large, thereby improving the structural strength of the first pole 12.

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

[0079] In the present embodiment, the number of conductive portions 22 electrically connected to the first pole 12 may be the same as or different from the number of through holes 121, and the number of conductive portions 22 is equal to or greater than the number of through holes 121, thereby ensuring that each through hole 121 is provided with at least one conductive portion 22. For example, if there are two conductive portions 22 electrically connected to the first pole 12, there may be two through holes 121 on the first pole 12. For example, if there are three conductive portions 22 electrically connected to the first pole 12, there may be two or three through holes 121 on the first pole 12. Providing two through holes 121 is advantageous for improving the structural strength of the first pole 12 and the electrical connection area with the conductive portions 22.

[0080] For example, if the number of conductive parts 22 electrically connected to the first pole 12 is four, the number of through holes 121 on the first pole 12 may be two, three, or four. If two through holes 121 are provided, it is advantageous to improve the structural strength of the first pole 12 and the electrical connection area with the conductive parts 22. If four through holes 121 are provided, it is advantageous to significantly reduce the space occupied by the conductive parts 22 within the casing 11 and improve the energy density of the battery cell 10.

[0081] 4, 7, and 8, in some embodiments of the present application, the battery core assembly 2 includes at least one electrode assembly 20. That is, the battery core assembly 2 may include one or more electrode assemblies 20, and each electrode assembly 20 includes a conductive portion 22. For example, when there is one electrode assembly 20, the electrode assembly 20 includes a plurality of conductive portions 22 electrically connected to each of the first poles 12. For example, when there is a plurality of electrode assemblies 20, each electrode assembly 20 includes at least one conductive portion 22 electrically connected to each of the first poles 12. In this way, a plurality of electrode assemblies 20 may have a plurality of conductive portions 22 electrically connected to the first poles 12.

[0082] In the embodiment of the present application, a through hole 121 is provided at a position on the first pole 12 corresponding to each electrode assembly 20. It should be noted that the orthogonal projection of the through hole 121 along the extending direction of the tab on which the through hole 121 is located indicates the position of the electrode assembly 20 to which the through hole 121 corresponds. In the embodiment of the present application, the orthogonal projection of at least one through hole 121 along the extending direction of the tab on any one electrode assembly 20 is located thereon, i.e., at least one through hole 121 is provided at a position on the first pole 12 corresponding to each electrode assembly 20.

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

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

[0085] 8 , for example, when the first electrode post 12 has through holes 121 at positions corresponding to the electrode assemblies 20, the first electrode post 12 has the through holes 121 at positions corresponding to the connection root portions 223 of at least one of the electrode assemblies 20. That is, the orthogonal projection of the connection root portions 223 of at least one conductive portion 22 of each electrode assembly 20 along the extending direction of the tab is located within the through holes 121. This allows the conductive portion 22 to pass through the through holes 121 corresponding to its connection root portion 223, thereby shortening the extension length of the connection portions 222 of the conductive portion 22 within the casing 11 and reducing the space occupied by the conductive portion 22 within the casing 11, which is advantageous for improving the energy density of the battery cell 10. This also reduces the redundancy of the conductive portion 22 within the casing 11, which is advantageous for reducing the risk of the conductive portion 22 forming a short circuit with the active material-coated portion 21.

[0086] 8 , when the first electrode post 12 is provided with through-holes 121 at positions corresponding to the connection root portions 223 of the electrode assemblies 20, the extension length of the connection portions 222 of the conductive parts 22 within the casing 11 can be shortened, reducing the space occupied by each conductive part 22 within the casing 11, which is advantageous for further improving the energy density of the battery cell 10. In addition, the redundancy of each conductive part 22 within the casing 11 can be reduced, which more effectively reduces the redundancy of the conductive parts 22 within the casing 11 and the risk of short-circuiting with the active material-coated parts 21, which is advantageous for improving the reliability of the battery cell 10.

[0087] 8 , in some embodiments of the present application, the first electrode post 12 is provided with a through hole 121 corresponding to a middle region 201 in the thickness direction of each electrode assembly 20. That is, for any one electrode assembly 20, the orthogonal projection of at least one through hole 121 along the extending direction of the tab is located in the middle region 201 of the corresponding electrode assembly 20. In the present application, the "middle region 201 in the thickness direction of the electrode assembly 20" is understood in a broad sense and refers to a region between 1 / 3 and 2 / 3 of the thickness along the thickness direction of the electrode assembly 20.

[0088] In this way, by locating the through hole 121 close to or nearly close to the center of the electrode assembly 20, regardless of where the conductive portions 22 on the electrode assembly 20 extend from and how many of them extend from, they can all be relatively close to the centrally located through hole 121, thereby preventing the conductive portions 22 from extending too far before passing through the through hole 121 and further effectively reducing the space occupied by each conductive portion 22 within the casing 11.

[0089] 8 , when through-holes 121 are provided on the first electrode post 12 at positions corresponding to the electrode assemblies 20, for example, the connection root portion 223 of at least one conductive portion 22 of the electrode assemblies 20 corresponds to the middle region 201 in the thickness direction of the electrode assembly 20. In other words, for any one electrode assembly 20, the orthogonal projection of at least one connection root portion 223 along the extending direction of the tab is located in the middle region 201 of the corresponding electrode assembly 20.

[0090] For example, when the connection root portion 223 of the conductive portion 22 corresponds to the 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 1 / 2 of the product of the number of tab sheets 220 provided in the conductive portion 22 and the thickness of each tab sheet 220.

[0091] This allows the tab sheets 220 of the conductive portions 22 in the electrode assemblies 20 to converge toward or approximately toward the center, which is advantageous for reducing the convergence height of the conductive portions 22 and thereby reducing the dimension occupied by the conductive portions 22 in the direction in which the tabs extend within the casing 11, which is advantageous for increasing the occupyable space of the active material-coated portions 21 in the direction in which the tabs extend, and for improving the energy density of the battery cell 10. Furthermore, the distance between the conductive portions 22 converging toward or approximately toward the center and each of the through holes 121 corresponding to the corresponding electrode assemblies 20 may be relatively short, which prevents the conductive portions 22 from extending too far before passing through the through holes 121 and further effectively reduces the space occupied by each conductive portion 22 within the casing 11.

[0092] Furthermore, when the connection root 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 a through hole 121 is provided at a position corresponding to the connection root portion 223 of each conductive portion 22 on the first pole 12, the first pole 12 is provided with a through hole 121 corresponding to the intermediate region 201 in the thickness direction of each electrode assembly 20, which is more advantageous in reducing the distance from the conductive portion 22 to the through hole 121, and shortening the extension length of the conductive portion 22 within the casing 11 before it passes through the through hole 121, thereby effectively reducing the space occupied by the conductive portion 22 within the casing 11.

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

[0094] For example, the two electrode assemblies 20 shown in FIG. 10 are a combination, in which the left electrode assembly 20 has two positive electrode conductive portions 22, the right electrode assembly 20 also has two positive electrode conductive portions 22, and one of the two positive electrode conductive portions 22 of the left electrode assembly 20 that is adjacent to the right side is connected to one of the two positive electrode conductive portions 22 of the right electrode assembly 20 that is adjacent to the left side.

[0095] Therefore, if each electrode assembly 20 extends from two positive electrode conductive portions 22 and two electrode assemblies 20 share four mutually independent positive electrode conductive portions 22, it is necessary to open four through holes 121 in the first positive electrode pole 12. In contrast to this proposal, the above embodiment connects and installs two of the positive electrode conductive portions 22, so that only three through holes 121 are required in the first positive electrode pole 12, thereby reducing the number of independent conductive portions 22 to be combined to a certain extent and further reducing the number of through holes 121 on the first electrode pole 12, thereby improving the structural strength of the first electrode pole 12 and improving assembly efficiency. When the thickness of each of the two electrode assemblies 20 is relatively large and each electrode assembly 20 has only one positive electrode conductive portion 22 extending therefrom, 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 of the conductive portion 22 in the extension direction of the tabs is relatively high, and the space occupied is relatively large. In contrast to this, in the above embodiment, each electrode assembly 20 has two positive electrode conductive portions 22 extending therefrom, thereby reducing the number of tab sheets 220 provided on each conductive portion 22 to a certain extent and reducing the space occupied by each conductive portion 22 in the extension direction of the tabs.

[0096] Therefore, in the above technical solution, 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 electrode post 12, and advantageously reducing the space occupied by the conductive parts 22 in the casing 11 in the extending direction of the tabs.

[0097] 8 , in some embodiments of the present application, each conductive portion 22 is drilled in one of the through holes 121 closest to the corresponding connection root portion 223. By drilling each conductive portion 22 in the through hole 121 closest to its respective connection root portion 223 in this manner, the conductive portion 22 is allowed to extend through a selected through hole 121 that is relatively close to the conductive portion 22, which is advantageous for shortening the extension length of the conductive portion 22 within the casing 11 before passing through the through hole 121, reducing the space occupied by the conductive portion 22 within the casing 11 and improving the energy density of the battery cell 10, and also for reducing redundancy of the conductive portion 22 within the casing 11, which effectively reduces the risk of short-circuiting between the conductive portion 22 and the active material-coated portion 21 within the casing 11 and improving the reliability of the battery cell 10.

[0098] 8 , when the first pole 12 has through holes 121 at positions corresponding to the connection root portions 223, each conductive portion 22 can penetrate a shorter distance from the through hole 121 corresponding to its connection root portion 223, thereby further shortening the extension length of the connection portion 222 of each conductive portion 22 within the casing 11 and 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. In addition, this reduces the redundancy of each conductive portion 22 within the casing 11, more effectively reducing the risk of short-circuiting between the conductive portion 22 and the active material-coated portion 21 within the casing 11, which is advantageous for improving the reliability of the battery cell 10.

[0099] 11 to 15, Fig. 11 is a perspective view of a first electrode post 12 provided according to some embodiments of the present application, Fig. 12 is an orthographic view of the first electrode post 12 shown in Fig. 11, Fig. 13 is a cross-sectional view taken along line DD in Fig. 12, Fig. 14 is an orthographic view of a battery cell 10 provided according to some embodiments of the present application, and Fig. 15 is a locally enlarged view of a portion E shown in Fig. 14. In some embodiments of the present application, the through-hole 121 is an elongated hole, the conductive portion 22 has a connecting portion 222 drilled in the through-hole 121, the connecting portion 222 is sheet-shaped, and the length direction of the portion of the connecting portion 222 located in the through-hole 121 coincides with the length direction of the through-hole 121 (e.g., the second direction X shown in Fig. 15), and the width direction of the through-hole 121 (e.g., the third direction Y shown in Fig. 15) coincides with the thickness direction of the connecting portion 222.

[0100] As a result, by arranging the through hole 121 in an elongated shape that roughly matches the shape of the connection part 222 of the conductive part 22, the connection part 222 of the conductive part 22 can easily pass through the through hole 121, and after the conductive part 22 passes through the through hole 121, the space left in the through hole 121 can be relatively small, which is advantageous in reducing the size of the through hole 121, making it easier to seal the subsequent through hole 121, and is advantageous in improving the structural strength of the first pole post 12.

[0101] 12 and 15, for example, the spacing direction of the plurality of through holes 121 on the first pole 12 (e.g., the third direction Y shown in FIG. 15) is different from the length direction of the through holes 121 (e.g., the second direction X shown in FIG. 15). That is, the spacing direction of the plurality of through holes 121 on the first pole 12 is at an angle intersecting with the length direction of the through holes 121. In this way, the plurality of through holes 121 may be arranged at intervals along a direction intersecting with the length direction of the through holes 121. This can reduce the space occupied by the plurality of through holes 121 relative to the first pole 12 in the length direction of the through holes 121. This is advantageous for reducing the dimension of the through holes 121 of the first pole 12 in the length direction, and is advantageous for designing the first pole 12 to be more compact. For example, the multiple through holes 121 may be spaced apart along the width direction of the through holes 121 (e.g., the third direction Y shown in FIG. 15), thereby reducing the space occupied by the through holes 121 relative to the first pole post 12 and being more advantageous for a compact design of the first pole post 12.

[0102] 15 again, for example, the length L1 of the through hole 121 is equal to or greater than 1.1 times the length a of the portion of the connecting portion 222 located within the through hole 121, and is equal to or less than 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, so the conductive portion 22 can pass through the through hole 121 smoothly, and the width L2 of the through hole 121 is not too large, so the gap between the conductive portion 22 and the through hole 121 after mating is relatively small, which is advantageous for sealing and for improving the structural strength of the first terminal post 12, or for reducing the size and cost of the first terminal post 12 while maintaining the same structural strength.

[0103] Specifically, a cross section of the sample is cut for both the length a and the length L1, and then dimensional measurements can be performed using a two-dimensional projection measuring device or CT scan (i.e., an abbreviation for Computed Tomography).

[0104] Tests have shown that when the length a is 20 mm and the length L1 is 1.09a, or 21.8 mm, the manufacturing positional deviation tolerance of the connection portion 222 is 4 mm, which means there is a risk of interference with the edge of the through-hole 121 during drilling. When the length a is 20 mm and the length L1 is a+23 mm, or 43 mm, the size of the first terminal post 12 must be increased, which increases material costs and reduces the structural strength of the first terminal post 12. When the length a is 20 mm and the length L1 is approximately 33.8 mm, not only is assembly with the through-hole 121 easier, but the size of the first terminal post 12 can be reduced, saving material costs and improving the structural strength of the first terminal post 12.

[0105] 15 again, in combination with FIG. 16, which is a local cross-sectional view of a battery cell 10 provided according to some embodiments of the present application, exemplarily, the width L2 of the through hole 121 is greater than or equal to 1.1 times the total thickness b of all the connection portions 222 located within the through hole 121 and is less than or equal to the sum of the total thickness b of all the connection portions 222 located within the through hole 121 and 7 mm, i.e., 1.1b≦L2≦b+7 mm. As a result, because the width L2 of the through hole 121 is not too small, the conductive portion 22 can 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 portion 22 and the through hole 121 after mating is relatively small, which facilitates sealing and is advantageous for improving the structural strength of the first electrode post 12, or for reducing the size and cost of the first electrode post 12 while maintaining the same structural strength.

[0106] Specifically, a cross section of the sample can be cut for both the length b and the length L2, and then dimensional measurements can be performed using a two-dimensional projection measuring device or CT scan (i.e., an abbreviation for Computed Tomography).

[0107] Tests have shown that when length b is 0.6 mm and length L2 is 1.09b, i.e., 0.654 mm, the positional deviation of connection portion 222 from that of through-hole 121 is greater than 0.2 mm, risking interference with the edge of through-hole 121 during drilling. When length b is 0.6 mm and length L2 is b+7.1 mm, i.e., 7.7 mm, the dimensions of first pole 12 must be increased, resulting in relatively high material costs and relatively low structural strength of first pole 12. When length b is 0.6 mm and length L2 is approximately 3 mm, not only is assembly with through-hole 121 easier, but the dimensions of first pole 12 can be reduced, saving material costs and improving structural strength of first pole 12.

[0108] 8 , in some embodiments of the present application, the first electrode post 12 has an accommodating groove 124 communicating with the through-hole 121, and a portion of the conductive portion 22 passes through the through-hole 121 and is accommodated in the accommodating groove 124. As can be understood, the accommodating groove 124 is a groove having a certain depth. In the above technical solution, the accommodating groove 124 is provided in the first electrode post 12, thereby reducing the weight of the first electrode post 12 and improving the weight-energy density of the battery cell 10. Furthermore, accommodating a portion of the conductive portion 22 in the accommodating groove 124 reduces the space occupied by the casing 11 and increases the volume of the active material-coated portion 21, thereby improving the volumetric energy density of the battery cell 10.

[0109] Referring again to FIG. 8 , for example, the first pole 12 has an end wall 122 and a side wall 123. The end wall 122 is located on one side of the side wall 123, which is close to the inside of the casing 11. The end wall 122 and the side wall 123 surround and form an accommodating groove 124. The slot opening 1241 of the accommodating groove 124 opens toward one side away from the inside of the casing 11. That is, the surface of the first pole 12 on the side away from the inside of the casing 11 is the pole outer end surface 125, and the slot opening 1241 of the accommodating groove 124 penetrates the pole outer end surface 125. A plurality of through holes 121 are opened in the end wall 122, connecting the accommodating groove 124 to the inside of the casing 11. The outer end 224 of the conductive part 22 is inserted into the accommodating groove 124 through the through hole 121 and connected to the end wall 122.

[0110] For example, when the first electrode post 12 is installed on the top wall of the casing 11 and the electrode post outer end face 125 is the upper surface of the first electrode post 12, the accommodating groove 124 is formed as a recessed groove with the groove opening 1241 opening upward and the groove walls recessed downward (i.e., recessed in the direction approaching the battery core assembly 2). Also, when the first electrode post 12 is installed on the bottom wall of the casing 11 and the electrode post outer end face 125 is the lower surface of the first electrode post 12, the accommodating groove 124 is formed as a recessed groove with the groove opening 1241 opening downward and the groove walls recessed upward (i.e., recessed in the direction approaching the battery core assembly 2).

[0111] In the above technical solution, the accommodating groove 124 opens toward one side of the first pole 12 that is away from the inside of the casing 11, which makes it advantageous to weld the conductive part 22 and the end wall 122 through the accommodating groove 124 from the outside of the first pole 12, i.e., from the side away from the active material coating part 21 of the first pole 12. In other words, this makes it easy to externally weld the first pole 12 and the conductive part 22 through the accommodating groove 124, which facilitates the processing and manufacturing of the battery cell 10 and reduces processing and manufacturing costs.

[0112] For example, the accommodating groove 124 may be configured in a shape in which the cross-sectional length is greater than the width, such as a rectangle, an oval, or a racetrack shape, and the weld mark formed by welding the conductive portion 22 to the first pole post 12 may be an elongated weld mark parallel to the length direction of the accommodating groove 124 so as to improve the reliability of the welding and increase the current passing performance.

[0113] 8, in some alternative embodiments of the present application, outer ends 224 of the plurality of conductive portions 22 connected to the end wall 122 are stacked and connected on the end wall 122, i.e., the plurality of conductive portions 22 on the end wall 122 are stacked and connected together to form an electrical connection with the first terminal post 12. In this way, by stacking and installing the outer ends 224 of the plurality of conductive portions 22 on the end wall 122, the space occupied by the end wall 122 can be reduced, which is advantageous for a compact design of the first terminal post 12.

[0114] 16 , in another alternative embodiment of the present application, outer ends 224 of the plurality of conductive portions 22 connected to the end wall 122 are spaced apart on the end wall 122, i.e., the plurality of conductive portions 22 on the end wall 122 are not stacked and are each independently connected to the end wall 122 to form an electrical connection with the first electrode post 12. In this way, each conductive portion 22 is independently connected to the end wall 122, which is advantageous in improving the reliability of the electrical connection between each conductive portion 22 and the first electrode post 12.

[0115] 8 , the casing assembly 1 further includes a pole cover plate 13, which fits over the first pole 12 and seals the groove opening 1241, and is electrically connected to the first pole 12. In the above technical solution, the pole cover plate 13 is installed to seal the groove opening 1241 of the receiving groove 124, thereby preventing the electrolyte in the casing 11 from leaking through the groove opening 1241 of the receiving groove 124. Furthermore, the pole cover plate 13 seals the groove opening 1241 of the receiving groove 124 and is electrically connected to the first pole 12, so that the pole cover plate 13 can easily establish an indirect electrical connection between the first pole 12 and the bus member, which is advantageous in increasing the connection area of ​​the electrical connection and therefore advantageous in reducing the resistance of the electrical connection.

[0116] It should be noted that the fitting method and position of the electrode post cover plate 13 and the first electrode post 12 are not limited as long as the groove opening 1241 of the receiving groove 124 of the electrode post cover plate 13 can be sealed. For example, during processing, the conductive part 22 may first be inserted into the through hole 121 and welded to the end wall 122 of the receiving groove 124, and then the electrode post cover plate 13 may be welded to the first electrode post 12 to seal the groove opening 1241 of the receiving groove 124. It should be further noted that the specific structure of the electrode post cover plate 13 is not limited and may be, for example, an integral structure or a composite structure.

[0117] 3 to 8 and 11 to 15 again, a battery cell 10 according to a specific embodiment of the present invention 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, and one positive electrode post and one negative electrode post are provided in the casing 11, the positive electrode post and the negative electrode post are both first electrode posts 12, the battery core assembly 2 is housed in the casing 11 and comprises a plurality of electrode assemblies 20, each of the electrode assemblies 20 comprises an active material application portion 21 and a conductive portion 22, the conductive portion 22 comprises a converging portion 221 and a connecting portion 222, the converging portion 221 is formed by converging a plurality of tab sheets 220, and the connecting portion 222 comprises A plurality of tab sheets 220 are formed by converging and connecting, and the converging portion 221 is connected to the connection portion 222 and the active material application portion 21, and the connection portion 222 is welded to the first electrode column 12 and electrically connected to the first electrode column 12, and the connection position between the converging portion 221 and the connection portion 222 is the connection root portion 223, and the first electrode column 12 has through holes 121 respectively at positions corresponding to the connection root portions 223 of each conductive portion 22 of each electrode assembly 20, and the conductive portion 22 is drilled in the through holes 121 corresponding to the connection root portions 223, thereby drilling one conductive portion 22 in each through hole 121.

[0119] Furthermore, the first pole 12 has an end wall 122 and a side wall 123, the end wall 122 is located on one side of the side wall 123 close to the inside of the casing 11, the end wall 122 and the side wall 123 surround each other to form an accommodating groove 124, the groove opening 1241 of the accommodating groove 124 is open toward one side away from the inside of the casing 11, and a plurality of through holes 121 are all opened in the end wall 122 to connect the accommodating groove 124 to the inside of the casing 11, each through hole 121 is an elongated hole, and the plurality of through holes 121 on the end wall 122 are arranged at intervals along the width direction of the through holes 121. The conductive part 22 has a connecting part 222 drilled in the through hole 121, the length direction of the part of the connecting part 222 located inside the through hole 121 coincides with the length direction of the through hole 121, the width direction of the through hole 121 is installed along the thickness direction of the connecting part 222, the connecting part 222 is inserted into the accommodating groove 124 from the through hole 121 and welded to the end wall 122, and the multiple connecting parts 222 welded to the end wall 122 are stacked on the end wall 122 and welded together. A pole cover plate 13 is welded to the groove opening 1241, which seals the groove opening 1241 and is electrically connected to the first pole 12.

[0120] In the above technical solution, each first pole 12 in the battery cell 10 is perforated and connected to a plurality of conductive parts 22, and each conductive part 22 has a plurality of tab sheets 220 that are stacked and connected in a converging manner. This reduces the number of tab sheets 220 in each conductive part 22 and the converging height of the multiple tab sheets 220 in each conductive part 22. This reduces the dimension that each conductive part 22 occupies in the tab extension direction within the casing 11. When the dimension of the casing 11 is constant, this increases the space that the active material application part 21 can occupy in the tab extension direction, which is advantageous for improving the energy density of the battery cell 10.

[0121] According to some embodiments of the present application, the present application further provides a battery 100 including the battery cell 10 of any one of the above embodiments. In the above technical solution, the above battery cell 10 is installed in the battery 100, so that the energy density of the battery cell 10 can be improved, which is advantageous for improving the energy density of the battery 100.

[0122] According to some embodiments of the present application, the present application further provides an electric device 1000 including the battery 100 of the above embodiments, where the battery 100 is used to supply electric energy to the electric device 1000. In the above technical solution, the above battery 100 is installed in the electric device 1000, so that the energy density of the battery 100 can be improved, which is advantageous to extend the usage time of the electric device 1000. It should be understood that, when the electric device 1000 is a vehicle, the improved usage time of the battery 100 is advantageous to extend the driving range of the vehicle.

[0123] It should be noted that the embodiments and features of the embodiments of the present application can be combined with each other unless there is a contradiction.

[0124] The above is merely a preferred embodiment of the present application, and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent replacements, improvements, etc. made within the scope of the present application without departing from the spirit and principles of the present application should be included in the scope of the claims of the present application.

Claims

1. A battery cell, a casing assembly including a casing and a first pole mounted on the casing; a battery core assembly, the battery core assembly being housed in the casing and including a conductive part electrically connected to the first pole, the conductive part including a plurality of tab sheets arranged in a stacked manner and connected in a converging manner; A plurality of the conductive portions are electrically connected to the first pole, and the first pole has a plurality of through holes, and at least one of the conductive portions is provided in each of the through holes. Battery cell.

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

3. the electrode assembly includes an active material application portion, the conductive portion includes a converging portion and a connecting portion, the converging portion is formed by converging a plurality of the tab sheets, the connecting portion is formed by converging and connecting a plurality of the tab sheets, and is used for electrical connection with the first electrode post, the converging portion connects the connecting portion and the active material application portion, a connection position between the converging portion and the connecting portion is a connection root portion, and the first electrode post is provided with the through hole at a position corresponding to the connection root portion of at least one of the electrode assemblies; The battery cell according to claim 2 .

4. the first electrode posts are provided with the through holes corresponding to intermediate regions in the thickness direction of the electrode assemblies, respectively; The battery cell according to claim 2 or 3.

5. the electrode assembly includes an active material application portion, the conductive portion includes a converging portion and a connecting portion, the converging portion is formed by converging a plurality of the tab sheets, the connecting portion is formed by converging and connecting a plurality of the tab sheets, and is used for electrical connection with the first electrode post, the converging portion connects the connecting portion and the active material application portion, a connection position between the converging portion and the connecting portion is a connection root portion, and the connection root portion of at least one of the electrode assemblies corresponds to an intermediate region in the thickness direction of the electrode assembly; The battery cell according to any one of claims 2 to 4.

6. The battery core assembly includes at least one combination, and each combination includes two of the electrode assemblies. Each of the electrode assemblies in each combination includes a plurality of the conductive portions of the same polarity. In each combination, at least two of the conductive portions of the same polarity that belong to different electrode assemblies and are arranged adjacent to each other are connected and installed. The battery cell according to any one of claims 2 to 5.

7. the battery core assembly includes at least one electrode assembly, each of the electrode assemblies including at least one conductive portion, the electrode assembly including an active material application portion, the conductive portion including a converging portion and a connecting portion, the converging portion being formed by converging a plurality of the tab sheets, the connecting portion being formed by converging and connecting a plurality of the tab sheets, and used for electrical connection with the first electrode post, the converging portion connecting the connecting portion and the active material application portion, a connection position between the converging portion and the connecting portion being a connection root portion, and the conductive portion being drilled in one of the through holes nearest to the corresponding connection root portion; The battery cell according to any one of claims 1 to 6.

8. the through holes are provided at positions on the first pole corresponding to the connection root portions of the conductive portions, The battery cell according to any one of claims 3, 5 and 7.

9. The through hole is an elongated hole, the conductive portion has a connection portion drilled in the through hole, the connection portion is sheet-shaped, and the length direction of the portion located in 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 connection portion. The battery cell according to any one of claims 1 to 8.

10. a spacing direction of the plurality of through holes in the first pole pillar is different from a length direction of the through holes; The battery cell of claim 9 .

11. The conductive portion is composed of a plurality of the tab sheets, and the tab sheets are welded to the first pole, or the conductive portion further includes an adapter sheet, and the tab sheet is connected to the first pole via the adapter sheet. The battery cell according to any one of claims 1 to 10.

12. the first pole has an accommodating groove communicating with the through hole, and a portion of the conductive portion passes through the through hole and is accommodated in the accommodating groove; The battery cell according to any one of claims 1 to 11.

13. the first pole includes an end wall and a side wall, the end wall being located on one side of the side wall close to the interior of the casing, the end wall and the side wall surrounding each other to form the accommodating groove, the groove opening of the accommodating groove being open toward one side away from the interior of the casing, the plurality of through holes being all opened in the end wall to connect the accommodating groove to the interior of the casing, and the outer end of the conductive part being inserted into the accommodating groove through the through hole and connected to the end wall; The battery cell of claim 12.

14. The outer ends of the plurality of conductive parts connected to the end wall are stacked and connected to the end wall, or the outer ends of the plurality of conductive parts connected to the end wall are installed at intervals on the end wall. The battery cell of claim 13.

15. The casing assembly further includes a pole cover plate, the pole cover plate being fitted to the first pole and sealingly capping the groove opening, and the pole cover plate being electrically connected to the first pole. The battery cell according to claim 13 or 14.

16. a plurality of poles are provided on the casing, at least one of which is the first pole; The battery cell according to any one of claims 1 to 15.

17. A battery cell according to any one of claims 1 to 16, battery.

18. 18. The battery of claim 17, Electrical equipment.

Images