Battery cell, battery, and power consumption device

Abstract

SOLUTION: A battery cell includes an electrode assembly including a first tab 11, a case for accommodating the electrode assembly, and an electrode terminal installed in the case, electrically connected to the first tab, and provided with a first through hole 323 for injecting an electrolyte into an internal space of the case, in which the electrode assembly has a wound structure, and the electrode assembly has a second through hole 14 at a center of the wound structure, the first through hole is in communication with the second through hole so that the electrolyte injected through the first through hole can flow into the second through hole, and further includes a current collecting component 40 for electrically connecting the electrode terminal and the first tab, the current collecting component includes a third through hole 45, and at least a part of the third through hole is provided between the first through hole and the second through hole.EFFECT: By providing a first through hole for injecting an electrolyte, deformation of a case in an injection process can be reduced, a structure of a battery cell can be simplified, and an influence of the first through hole on a strength of the case can be reduced.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to an application filed on August 23, 2021, entitled "Battery cell and manufacturing method and system therefor, battery and power consumption device," with international application number PCT / CN2021 / 114156, the entire contents of which are incorporated herein by reference.

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

[0003] Battery cells are widely used in electronic devices, such as mobile phones, laptops, battery cars, electric vehicles, electric airplanes, electric steamships, electric toy cars, electric toy steamships, electric toy airplanes, and power tools. Battery cells may include nickel-cadmium battery cells, nickel-metal hydride battery cells, lithium-ion battery cells, and secondary alkaline zinc-manganese battery cells.

[0004] In the development of battery technology, how to simplify the structure of battery cells is one research direction of battery technology. Summary of the Invention

[0005] The present application provides a battery cell, a battery, and a power consuming device, which can simplify the structure of the battery cell.

[0006] According to a first aspect, an embodiment of the present application provides a battery cell, the battery cell including an electrode assembly, a case, and an electrode terminal. The electrode assembly includes a first tab. The case is used to house the electrode assembly. The electrode terminal is installed in the case and electrically connected to the first tab, and the electrode terminal is provided with a first through-hole for injecting an electrolyte into the interior space of the case.

[0007] In the above technical solution, by opening a first through hole for injecting electrolyte into the electrode terminal, deformation of the case during the injection process can be reduced, the structure of the battery cell can be simplified, and the impact of the first through hole on the strength of the case can be reduced.

[0008] In some embodiments, the electrode terminal achieves electrical connection with the first tab by at least one first weld.

[0009] In the above technical solution, the first welded portion can reduce the resistance between the electrode terminal and the first tab, and improve the overcurrent capability.

[0010] In some embodiments, the number of first welds is one, and the first weld extends circumferentially around the first through hole and surrounds at least a portion of the first through hole.

[0011] In the above technical solution, the first welded portion can increase the strength of the area around the first through hole of the electrode terminal, and reduce deformation of the electrode terminal due to impact of the electrolyte.

[0012] In some embodiments, the first weld surrounds only a portion of the first through hole along a circumference of the first through hole.

[0013] In the above technical solution, the outer periphery of the first through hole is not sealed by the first weld, and the gap between the electrode terminal and the member welded to the electrode terminal is not blocked by the first weld, so that some of the electrolyte flowing in through the first through hole passes through this gap, thereby improving the efficiency of injecting the electrolyte.

[0014] In some embodiments, the angle that the first weld surrounds the first through hole is α, where 180°≦α≦360°.

[0015] α has a positive correlation with the overcurrent area of ​​the first weld. The smaller α is, the smaller the overcurrent area of ​​the first weld is, and the greater the heat generated when current flows through the first weld. In the above technical solution, α is limited to 180° to 360°, so that the first weld meets the overcurrent capacity and temperature rise requirements of the battery cell.

[0016] In some embodiments, the first weld is multiple and the multiple first welds are spaced apart circumferentially around the first through hole.

[0017] Assuming that the total area is constant, the method of installing multiple first welds can reduce the welding power per welding and reduce heat generation compared to the method of installing one first weld.

[0018] In some embodiments, the angle β between the first through holes of any two adjacent first welds along the circumferential direction is less than 30°.

[0019] The larger the value of angle β, the sparser the distribution of the first welds and the smaller the total overcurrent area of ​​the first welds, and the smaller the value of angle β, the denser the distribution of the first welds and the larger the total overcurrent area of ​​the first welds. In the embodiment of the present application, β is limited to less than 30° to meet the requirements of the battery cell for overcurrent capacity and temperature rise and reduce the risk of the first welds being torn when the battery cell vibrates.

[0020] In some embodiments, each first weld extends radially along the first through hole.

[0021] In the above technical solution, the first weld extends along the radial direction of the first through hole, and the size of the first weld along the circumferential direction of the first through hole can be reduced, and the electrode terminal can increase the overcurrent capacity and reduce heat generation by arranging more first welds around the outer periphery of the first through hole.

[0022] In some embodiments, the depth of the first weld in the axial direction of the first through hole is h, and the minimum pitch between the first weld and the first through hole in the radial direction of the first through hole is d, where d and h satisfy 0.1≦h / d≦0.6.

[0023] The larger h, the greater the power required for welding, the greater the heat generated during the welding process, the greater the thermal stress acting on the area close to the first through hole, and the greater the deformation of the first through hole. The smaller d, the greater the heat conducted to the area close to the first through hole during the welding process, the greater the thermal stress acting on the area close to the first through hole, and the greater the deformation of the first through hole. If h / d is too large, the first through hole will deform significantly, making it difficult for the injection head to fit into the first through hole, affecting injection efficiency. The above technical solution limits the value of h / d to 0.6 or less, thereby reducing the thermal stress acting on the area close to the first through hole, reducing deformation of the first through hole, and making it easier for the injection head to fit into the first through hole.

[0024] The smaller h is, the lower the overcurrent capacity and strength of the first weld, and the higher the risk of the first weld tearing when the battery cell vibrates. The larger d is, the smaller the area available for welding the electrode terminal, limiting the overcurrent capacity and strength of the first weld. If h / d is too small, the overcurrent capacity and strength of the first weld will be insufficient. The above technical solution limits the value of h / d to 0.1 or greater, so that the overcurrent capacity and strength of the first weld meet the requirements.

[0025] In some embodiments, d and h satisfy 0.2≦h / d≦0.5.

[0026] In some embodiments, 1.6 mm≦d≦5.5 mm.

[0027] If d is too small, too much heat is conducted to the area near the first through hole during the welding process, and the thermal stress acting on the area near the first through hole is too great, causing the first through hole to deform significantly. The injection head is difficult to fit into the first through hole, affecting injection efficiency. If d is too large, the area available for welding the electrode terminal is small, and the overcurrent capacity and strength of the first weld are insufficient. The above technical solution limits the value of d to 1.6 mm to 5.5 mm, thereby minimizing deformation of the first through hole, making it easier for the injection head to fit into the first through hole, and ensuring that the overcurrent capacity and strength of the first weld meet the requirements.

[0028] In some embodiments, the electrode assembly has a wound structure, and the electrode assembly has a second through-hole at a center of the wound structure, and the first through-hole communicates with the second through-hole so that the electrolyte injected through the first through-hole can flow into the second through-hole.

[0029] In the above technical solution, during the injection process, the electrolyte can flow into the second through-hole through the first through-hole, and the electrolyte flowing into the second through-hole can infiltrate into the electrode assembly from the inside, thereby improving the infiltration efficiency of the electrode assembly.

[0030] In some embodiments, a projection of the first through hole at least partially overlaps a projection of the second through hole in the axial direction of the first through hole.

[0031] In the above technical solution, the first through hole and the second through hole are opposite to each other along the axial direction of the first through hole, and a portion of the electrolyte passing through the first through hole enters the second through hole without changing its flow, thereby improving the infiltration efficiency of the electrode assembly.

[0032] In some embodiments, the projection of the second through hole in the axial direction of the first through hole is larger than the projection of the first through hole.

[0033] In the above technical solution, the second through-hole has a relatively larger cross-sectional area than the first through-hole, and thus the second through-hole can accommodate more electrolyte and contribute to improving the efficiency of the electrolyte infiltrating into the electrode assembly from the inside.

[0034] In some embodiments, in the axial direction of the first through hole, a projection of the first through hole lies within a projection of the second through hole.

[0035] According to the above technical solution, the entity part of the electrode assembly can avoid the first through-hole, reducing the electrolyte that directly impacts the electrode assembly, and reducing the risk of deformation of the electrode assembly.

[0036] In some embodiments, the diameter of the first through hole is D1, the diameter of the second through hole is D2, and D1 and D2 satisfy 65%≦D1 / D2≦95%.

[0037] The larger D1 is, the higher the efficiency of electrolyte injection, the shorter the time until the electrolyte is filled, the less electrolyte can infiltrate the electrode assembly during the injection process, and the smaller the total amount of electrolyte injected. The smaller D2 is, the smaller the wall area of ​​the second through-hole is, and the less efficient the electrolyte can infiltrate from the inside of the electrode assembly. If D1 / D2 is too large, the amount of electrolyte injected will be small, which will affect the cycle life of the battery cell. In the above technical solution, the value of D1 / D2 is limited to 95% or less, so that the amount of electrolyte injected meets the requirement.

[0038] The smaller D1, the lower the electrolyte injection efficiency and the longer it takes for the electrolyte to fill. The larger D2, the higher the efficiency of the electrolyte seeping into the electrode assembly. If D1 / D2 is too small, the injection time is long and the production efficiency is low. Furthermore, the larger D2, the smaller the capacity of the electrode assembly, the lower the internal space utilization rate of the battery cell, and the lower the energy density of the battery cell. The above technical solution limits the value of D1 / D2 to 65% or more to increase the injection efficiency and reduce the loss of energy density of the battery cell due to the second through-hole.

[0039] In some embodiments, D2≧D1+0.2 mm.

[0040] When assembling a battery cell, due to assembly errors, the electrode assembly may be misaligned, causing the first through-hole to face the entity part of the electrode assembly, resulting in the electrode assembly being struck by the electrolyte. The above technical solution sets D2≧D1+0.2mm to provide a margin for misalignment for the electrode assembly, reducing the risk of the entity part of the electrode assembly facing the first through-hole, reducing the amount of electrolyte directly striking the electrode assembly, and reducing the risk of the electrode assembly being deformed.

[0041] In some embodiments, the battery cell further includes a current collecting component for electrically connecting the electrode terminal and the first tab, the current collecting component including a third through hole, at least a portion of the third through hole being disposed between the first through hole and the second through hole.

[0042] In the above technical solution, by installing the third through-hole, the current collecting element avoids the electrolyte flowing in through the first through-hole, reducing the current collecting element's resistance to the electrolyte during the injection process, allowing the electrolyte to smoothly pass through the third through-hole and flow into the second through-hole, thereby improving the infiltration efficiency of the electrode assembly.

[0043] In some embodiments, the projection of the third through hole in the axial direction of the first through hole is smaller than the projection of the second through hole.

[0044] In the above technical solution, the second through-hole has a relatively larger cross-sectional area than the third through-hole, and thus the electrolyte that passes through the third through-hole can quickly flow into the second through-hole, which can contribute to improving the efficiency of the electrolyte infiltrating into the electrode assembly from the inside.

[0045] In some embodiments, the projection of the third through hole in the axial direction of the first through hole is larger than the projection of the first through hole.

[0046] In the above technical solution, the third through-hole has a larger cross-sectional area than the first through-hole, which reduces the risk of the current collecting part blocking the first through-hole, and the electrolyte can smoothly pass through the third through-hole and enter the second through-hole, thereby improving the efficiency of the electrolyte infiltrating into the electrode assembly from the inside.

[0047] In some embodiments, in the axial direction of the first through hole, a projection of the first through hole lies within a projection of the third through hole.

[0048] The above technical solution can reduce the risk of the current collecting component blocking the first through hole, allowing the electrolyte to flow smoothly into the case, and also reduces the impact on the current collecting component, reducing the risk of the connection between the current collecting component and the electrode terminal being torn.

[0049] In some embodiments, a projection of the third through hole lies within a projection of the second through hole in the axial direction of the first through hole.

[0050] The above technical solution can reduce the shielding of the third through-hole of the entity part of the electrode assembly, and the electrolyte can smoothly flow into the second through-hole.

[0051] In some embodiments, the first through-hole, the second through-hole, and the third through-hole are coaxially disposed.

[0052] In the above technical solution, the three through holes are arranged coaxially, which can make the electrolyte flow more smoothly and reduce the impact of the electrolyte on the current collecting element and the electrode assembly.

[0053] In some embodiments, the electrode terminal includes a seal plate and a terminal body, the terminal body having a first through hole, and the seal plate is connected to the terminal body and is used to seal the first through hole.

[0054] In the above technical solution, after the process related to the first through hole is completed, a sealing plate is connected to the terminal body to reduce the risk of electrolyte leakage through the first through hole and improve the sealing performance.

[0055] In some embodiments, the terminal body includes a recess and a connecting portion located on a side of the recess facing the electrode assembly, the first through-hole passing through the connecting portion, and the connecting portion achieving electrical connection with the first tab by at least one first weld. At least a portion of the seal plate is received in the recess.

[0056] In the above technical solution, by forming a recess in the terminal body, the thickness of the connection part is reduced, thereby reducing the welding power required for welding, reducing the risk of burning other components, and improving safety.The recess provides an accommodation space for the seal plate, thereby reducing the size of the seal plate protruding from the terminal body, reducing the space occupied by the electrode terminal, and improving the energy density of the battery cell.

[0057] In some embodiments, the case includes a cylindrical body and a lid body connected to the cylindrical body, the cylindrical body being arranged to surround the outer periphery of the electrode assembly, the lid body being provided with an electrode lead-out hole, and the electrode terminal being arranged in the electrode lead-out hole.

[0058] In some embodiments, the lid and the barrel are integrally molded, eliminating the need for a connection process between the lid and the barrel. When the lid and the barrel are electrically connected to the positive or negative electrode of the electrode assembly, the connection between the lid and the barrel has a single-piece structure, which reduces the resistance at the connection, thereby enhancing overcurrent capability. The lid may also be used to connect to an external component (e.g., a busbar member). If the battery cell is subjected to external impact, the external component may pull the lid, exerting force on the connection between the lid and the barrel. By integrating the lid and the barrel, the technical solution improves the strength of the connection between the lid and the barrel and reduces the risk of the lid and the barrel failing.

[0059] In some embodiments, the electrode assembly further includes a second tab, the second tab being opposite in polarity to the first tab, the second tab being electrically connected to the lid.

[0060] In the above technical solution, one of the cover and the electrode terminal may be the positive output terminal of the battery cell, and the other may be the negative output terminal of the battery cell, and the above technical solution allows the positive output terminal and the negative output terminal to be located on the same side of the battery cell, thus simplifying the connection process between multiple battery cells.

[0061] In some embodiments, the first tab is located at an end of the electrode assembly toward the electrode terminal, and the second tab is located at an end of the electrode assembly away from the electrode terminal.

[0062] In the above technical solution, the first tab and the second tab are provided at opposite ends of the electrode assembly, respectively, so that the pitch between the first tab and the second tab can be increased, the risk of the first tab and the second tab becoming conductive can be reduced, and safety can be improved.

[0063] In some embodiments, the second tab is a negative tab and the base material of the case is steel.

[0064] In the above technical solution, the case is electrically connected to the negative electrode tab, i.e., the case is in a low potential state, and the steel case is not easily corroded by the electrolyte in a low potential state.

[0065] In some embodiments, the cylindrical body has an opening at an end remote from the lid, and the battery cell further includes a cover plate for sealing the opening.

[0066] According to a second aspect, an embodiment of the present application provides a battery, the battery including a battery cell according to any one of the embodiments of the first aspect.

[0067] According to a third aspect, an embodiment of the present application provides a power consuming device, the power consuming device including a battery of the second aspect for providing electrical energy. [Brief explanation of the drawings]

[0068] In order to more clearly explain the technical solutions of the embodiments of the present application, the following briefly introduces the drawings that need to be used in the embodiments of the present application. It is obvious that the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on the drawings without exerting any creative efforts. [Figure 1] 1 is a structural schematic diagram of a vehicle according to some embodiments of the present application. [Figure 2] 1 is an exploded schematic view of a battery according to some embodiments of the present application. [Figure 3] FIG. 3 is a structural schematic diagram of the battery module shown in FIG. [Figure 4] FIG. 1 is an exploded schematic view of a battery cell according to some embodiments of the present application. [Figure 5] 1 is a cross-sectional schematic view of a battery cell according to some embodiments of the present application. [Figure 6] FIG. 6 is a schematic enlarged view of a local portion of the battery cell shown in FIG. 5. [Figure 7] FIG. 7 is an enlarged schematic view of the area in the square frame B in FIG. [Figure 8] 1 is a schematic diagram of an electrode terminal of a battery cell according to some embodiments of the present application. [Figure 9] FIG. 8 is an enlarged schematic view of the area surrounded by a circle C in FIG. 7. [Figure 10] 1 is a schematic diagram of a terminal body of an electrode terminal of a battery cell according to some embodiments of the present application. [Figure 11] 10 is a schematic diagram of a terminal body of an electrode terminal of a battery cell according to some other embodiments of the present application. [Figure 12] FIG. 10 is a schematic diagram of a terminal body of an electrode terminal of a battery cell according to still some embodiments of the present application. [Figure 13] 1 is a schematic cross-sectional view of a battery cell according to some other embodiments of the present application. [Figure 14] 1 is a schematic cross-sectional view of a battery cell according to some other embodiments of the present application. [Figure 15] FIG. 2 is a cross-sectional schematic view of a battery cell according to some further embodiments of the present application.

[0069] In the drawings, the drawings are not drawn to scale. DETAILED DESCRIPTION OF THE INVENTION

[0070] In order to clarify the objectives, technical solutions and advantages of the embodiments of the present application, the following will clearly describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without any creative efforts fall within the scope of protection of the present application.

[0071] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the art of this application, and the terms used in the specification of this application are only for describing specific embodiments and are not intended to limit this application, and the terms "comprises," "has," and any variations thereof in the specification and claims of this application and the above drawings are intended to cover a non-exclusive "comprise." The terms "first," "second," etc. in the specification and claims of this application or the above drawings are not intended to describe a specific order or a hierarchical relationship, but are intended to distinguish different objects.

[0072] An "embodiment" referred to in this application means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of this phrase in various places in the specification do not necessarily all refer to the same embodiment, nor are they mutually exclusive, separate, or alternative embodiments of other embodiments.

[0073] In the description of this application, it should be explained that unless otherwise clearly defined or limited, the terms "attached," "connected," "joined," and "attached" should be understood in a broad sense, and may refer to, for example, a fixed connection, a detachable connection, or an integral connection, a direct connection, an indirect connection via an intermediate medium, or internal communication between two elements. Those skilled in the art can understand the specific meanings of the above terms in this application according to specific circumstances.

[0074] The term "and / or" in this application merely describes the relationship between related objects and indicates that three relationships may exist, for example, A and / or B can represent three cases: A alone, a combination of A and B, and B alone. Also, the character " / " in this application generally indicates that the related objects before and after are in an "or" relationship.

[0075] In the embodiments of the present application, the same reference numerals represent the same elements, and for the sake of brevity, detailed descriptions of the same elements will be omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various elements in the embodiments of the present application shown in the drawings, and the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitations on the present application.

[0076] The term "plurality" as used herein refers to two or more (including two).

[0077] The term "parallel" in this application includes not only absolute parallelism but also approximately parallelism according to engineering standards, and the term "perpendicular" includes not only absolute perpendicularity but also approximately perpendicularity according to engineering standards.

[0078] In the present application, the battery cells may include lithium ion secondary battery cells, lithium ion primary battery cells, lithium sulfur battery cells, sodium lithium ion battery cells, sodium ion battery cells, magnesium ion battery cells, etc., and the embodiments of the present application are not limited thereto.

[0079] 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 include a battery module or a battery pack. The battery generally includes a housing for packaging one or more battery cells. The housing can prevent liquids or other foreign objects from affecting the charging or discharging of the battery cells.

[0080] The battery cell includes an electrode assembly and an electrolyte, and the electrode assembly includes a positive electrode plate, a negative electrode plate, and a separator. The battery cell operates primarily through the movement of metal ions between the positive electrode plate and the negative electrode plate. The positive electrode plate includes a positive electrode current collector and a positive electrode active material layer, with the positive electrode active material layer coated on the surface of the positive electrode current collector. The positive electrode current collector includes a positive electrode current collector and a positive electrode tab, with the positive electrode active material layer coated on the positive electrode current collector and the positive electrode tab not coated with the positive electrode active material layer. For example, in a lithium-ion battery, the positive electrode current collector may be made of aluminum, and the positive electrode active material layer includes a positive electrode active material, which may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode plate includes a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer is coated on the surface of the negative electrode current collector. The negative electrode current collector includes a negative electrode current collector and a negative electrode tab, and the negative electrode current collector is coated with the negative electrode active material layer, while the negative electrode tab is not coated with the negative electrode active material layer. The material of the negative electrode current collector may be copper, and the negative electrode active material layer includes a negative electrode active material, which may be carbon or silicon, etc. The material of the separator may be PP (polypropylene), PE (polyethylene), etc.

[0081] The battery cell further includes a case for accommodating the electrode assembly and electrode terminals installed in the case, the electrode terminals being electrically connected to the electrode assembly and used to charge and discharge the electrode assembly.

[0082] During the battery production process, it is necessary to inject electrolyte into the case. To achieve this, the inventors attempted to open a filling hole in the case. When injection is required, the injection head of the injection device is pressed against the case, and the injection head injects electrolyte into the case through the injection hole.

[0083] However, the inventors found that providing a filling hole in the case would complicate the case structure, occupy space in the case, and affect the installation of other components on the case. Compared with the electrode terminals, the case is relatively thin and has relatively low strength, so the filling head may extrude and deform the case during filling, which could result in defects in the battery cell's outer shape.

[0084] In view of this, the embodiments of the present application provide a technical solution in which through holes are opened in the electrode terminals for injecting electrolyte, thereby reducing the deformation of the case during the injection process, simplifying the structure of the battery cell, and reducing the impact of the first through holes on the strength of the case.

[0085] The technical solutions described in the embodiments of the present application are applicable to batteries and power-consuming devices that use batteries.

[0086] The power consuming devices may be vehicles, mobile phones, portable devices, laptops, steamships, spacecraft, electric toys, power tools, etc. The vehicles may be fuel oil vehicles, gas vehicles, or new energy vehicles, and the new energy vehicles may be pure electric vehicles, hybrid vehicles, or range extender vehicles, etc. The spacecraft may include airplanes, rockets, space shuttles, spaceships, etc. The electric toys may include stationary or mobile electric toys, such as game consoles, electric car toys, electric steamship toys, and electric airplane toys, etc. The power tools may include metal cutting power tools, polishing power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, hammer drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not particularly limit the above power consuming devices.

[0087] For convenience of explanation, the following embodiment will be described by taking an example in which the power consuming device is a vehicle.

[0088] 1 is a structural schematic diagram of a vehicle according to some embodiments of the present application. As shown in FIG. 1, a battery 2 is installed inside the vehicle 1, and the battery 2 may be installed at the bottom, head, or rear of the vehicle 1. The battery 2 may be used to power the vehicle 1, for example, the battery 2 may be used as an operating power source for the vehicle 1.

[0089] The vehicle 1 may further include a controller 3 and a motor 4, the controller 3 being used to control the battery 2 to power the motor 4, for example for starting the vehicle 1, navigation and operating power consumption needs during driving.

[0090] In some embodiments of the present application, the battery 2 can provide not only the operating power source for the vehicle 1 but also the driving power source for the vehicle 1, in place of, or in place of, fuel oil or natural gas.

[0091] 2 is an exploded schematic view of a battery according to some embodiments of the present application. As shown in FIG. 2, the battery 2 includes a housing 5 and a battery cell (not shown in FIG. 2), and the battery cell is housed in the housing 5.

[0092] The housing 5 is used to house the battery cells and may have various structures. In some embodiments, the housing 5 may include a first housing portion 5a and a second housing portion 5b, the first housing portion 5a and the second housing portion 5b being fitted together, and the first housing portion 5a, together with the second housing portion 5b, defining a housing space 5c for housing the battery cells. The second housing portion 5b may have a hollow structure with an open end, the first housing portion 5a having a plate-like structure, and the first housing portion 5a is fitted over the open side of the second housing portion 5b to form the housing 5 having the housing space 5c. Alternatively, both the first housing portion 5a and the second housing portion 5b may have a hollow structure with an open end, and the open side of the first housing portion 5a is fitted over the open side of the second housing portion 5b to form the housing 5 having the housing space 5c. Of course, the first housing part 5a and the second housing part 5b may have various shapes, for example, a cylinder, a rectangular parallelepiped, or the like.

[0093] In order to improve the sealing performance after the first housing part 5a and the second housing part 5b are connected, a sealing member, such as a sealant or a seal ring, may be installed between the first housing part 5a and the second housing part 5b.

[0094] If the first housing part 5a is placed on top of the second housing part 5b, the first housing part 5a may be called the upper housing cover, and the second housing part 5b may be called the lower housing.

[0095] The battery 2 may have one or more battery cells. When there are multiple battery cells, the multiple battery cells may be connected in series, in parallel, or in series-parallel. A series-parallel connection means that some of the multiple battery cells are connected in series and others are connected in parallel. The multiple battery cells may be directly connected in series, in parallel, or in series-parallel before the entire battery cell set is housed in the housing 5. Of course, the multiple battery cells may first be connected in series, in parallel, or in series-parallel to form a battery module 6, and the multiple battery modules 6 may then be connected in series, in parallel, or in series-parallel to form a whole and housed in the housing 5.

[0096] FIG. 3 is a structural schematic diagram of the battery module shown in FIG.

[0097] 3, there are a plurality of battery cells 7, and the plurality of battery cells 7 are first connected in series, in parallel, or in series-parallel to form a battery module 6. The plurality of battery modules 6 are then connected in series, in parallel, or in series-parallel to form a whole, which is housed in a housing.

[0098] The plurality of battery cells 7 in the battery module 6 are electrically connected by bus bar members 8, and can be connected in parallel, in series, or in series-parallel configuration among the plurality of battery cells 7 in the battery module 6. There may be one or more bus bar members, and each bus bar member 8 is used to electrically connect at least two battery cells.

[0099] FIG. 4 is an exploded schematic view of a battery cell according to some embodiments of the present application, FIG. 5 is a cross-sectional schematic view of a battery cell according to some embodiments of the present application, FIG. 6 is a locally enlarged schematic view of the battery cell shown in FIG. 5, and FIG. 7 is an enlarged schematic view of the corner frame B in FIG. 6.

[0100] 4 to 7 , a battery cell 7 according to an embodiment of the present application includes an electrode assembly 10, a case 20, and an electrode terminal 30. The electrode assembly 10 includes a first tab 11. The case 20 is used to house the electrode assembly 10. The electrode terminal 30 is installed in the case 20 and electrically connected to the first tab 11. The electrode terminal 30 is provided with a first through-hole 323 for injecting an electrolyte into the internal space of the case 20.

[0101] The electrode assembly 10 includes a first electrode plate and a second electrode plate having opposite polarities. One of the first electrode plate and the second electrode plate is a positive electrode plate, and the other is a negative electrode plate. Exemplarily, the electrode assembly 10 generates electrical energy through oxidation and reduction reactions that occur when ions are absorbed and released from the positive electrode plate and the negative electrode plate. Optionally, the electrode assembly 10 further includes a separator for insulating and separating the first electrode plate and the second electrode plate.

[0102] In some examples, the first electrode plate, the second electrode plate, and the separator are all strip-shaped, and the first electrode plate, the second electrode plate, and the separator are wound together around a central axis A to form a wound structure. The wound structure may be a cylindrical structure, a flat structure, or a structure with another shape. In other examples, the electrode assembly 10 may be a stacked structure formed by stacking the first electrode plate, the separator, and the second electrode plate.

[0103] The first tab 11 may be a portion of the first electrode plate that is not coated with an active material layer. The first tab 11 may be a positive electrode tab or a negative electrode tab.

[0104] The case 20 has a hollow structure, and the interior thereof forms a space for accommodating the electrode assembly 10. The case 20 may have various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, or a hexagonal prism shape. The shape of the case 20 may be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 has a cylindrical structure, a cylindrical case may be selected, and if the electrode assembly 10 has a rectangular parallelepiped structure, a rectangular parallelepiped case may be selected. Optionally, both the electrode assembly 10 and the case 20 are cylindrical.

[0105] The case 20 may be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and the embodiments of the present application are not particularly limited thereto.

[0106] The case 20 may be positively charged, negatively charged, or uncharged.

[0107] The electrode terminal 30 may be installed in an insulating manner on the case 20 or may be electrically connected to the case 20, but the embodiments of the present application are not limited thereto, as long as electrical conduction between the positive electrode plate and the negative electrode plate is avoided.

[0108] The electrode terminal 30 can be directly connected to the first tab 11 to realize an electrical connection between the electrode terminal 30 and the first tab 11. Illustratively, the electrode terminal 30 may be connected to the first tab 11 by adhesion, abutment, locking, welding, or other methods.

[0109] Instead, the electrode terminal 30 may be indirectly connected to the first tab 11 by another conductive part to realize the electrical connection between the electrode terminal 30 and the first tab 11. For example, the conductive part may be connected to the first tab 11 and the electrode terminal 30 simultaneously to realize the electrical connection between the electrode terminal 30 and the first tab 11.

[0110] The electrode terminals 30 may be output electrodes of the battery cells 7, which can electrically connect the battery cells 7 to an external circuit to realize charging and discharging of the battery cells 7. Optionally, the electrode terminals 30 are connected to bus bar members and used to realize electrical connection between the battery cells 7.

[0111] The number of first through-holes 323 may be one or more.

[0112] During the molding process of the battery cell 7, the first through-hole 323 can connect the space outside the case 20 to the interior space of the case 20. When injection is required, the injection head of the injection device is pressed against the electrode terminal 30, and the injection head injects the electrolyte into the case 20 through the first through-hole 323.

[0113] By opening the first through-hole 323 for injecting the electrolyte into the electrode terminal 30, deformation of the case 20 during the injection process can be reduced, the structure of the battery cell 7 can be simplified, and the impact of the first through-hole 323 on the strength of the case 20 can be reduced.

[0114] In some embodiments, the first through-holes 323 may be used for other processes, such as a conversion process.

[0115] During the chemical conversion process of the battery cell 7, gas is generated inside the case 20, and the first through-hole 323 may be used to release the gas inside the case 20 by communicating with an external negative pressure device.

[0116] In some embodiments, the electrode assembly 10 includes a main body 12, a first tab 11, and a second tab 13, with the first tab 11 and the second tab 13 protruding from the main body 12. The first tab 11 is a portion of the first electrode plate that is not coated with an active material layer, and the second tab 13 is a portion of the second electrode plate that is not coated with an active material layer.

[0117] The first tab 11 and the second tab 13 may extend from the same side of the body portion 12 or from opposite sides. The first tab 13 is located at the end of the electrode assembly 10 facing the electrode terminal 30 , and the second tab 13 is located at the end of the electrode assembly 10 facing away from the electrode terminal 30 .

[0118] In some embodiments, the first tab 11 is wound multiple times around the central axis A of the electrode assembly 10. In other words, the first tab 11 includes multiple turns of tab layers. After winding is complete, the first tab 11 has a generally cylindrical shape, with a gap remaining between two adjacent turns of the tab layer. In some embodiments of the present application, the first tab 11 may be treated to reduce the gap between the tab layers and facilitate connection of the first tab 11 to other components. For example, in some embodiments of the present application, the first tab 11 may be milled and flattened so that the end region of the first tab 11 away from the main body 12 is drawn and converged. This milling and flattening process forms a dense end face at the end of the first tab 11 away from the main body 12, reducing the gap between the tab layers and facilitating connection of the first tab 11 to other components. Alternatively, in some embodiments of the present application, a conductive material may be filled between two adjacent turns of the tab layer to reduce the gap between the tab layers.

[0119] In some embodiments, the second tab 13 is wound multiple times around the central axis A of the electrode assembly 10, and the second tab 13 includes a tab layer of multiple turns. Illustratively, the second tab 13 is also subjected to a milling and flattening process to reduce gaps between the tab layers of the second tab 13.

[0120] The electrode assembly 10 has a central axis A which is an imaginary straight line. The first electrode plate, the second electrode plate, and the separator may be wound around the central axis A.

[0121] In some embodiments, the case 20 includes a cylindrical body 21 and a cover body 22 connected to the cylindrical body 21, the cylindrical body 21 is arranged to surround the outer periphery of the electrode assembly 10, the cover body 22 is provided with an electrode lead-out hole 221, and the electrode terminal 30 is arranged in the electrode lead-out hole 221.

[0122] The cover 22 and the barrel 21 may be an integrally formed structure, i.e., the case 20 is an integrally molded part. Of course, the cover 22 and the barrel 21 may be two separate parts and connected by welding, crimping, adhesive, etc.

[0123] The electrode extraction hole 221 penetrates the cover 22 so as to facilitate extraction of electrical energy in the electrode assembly 10 to the outside of the case 20 .

[0124] The central axis A is an imaginary straight line. In some embodiments, the central axis A may pass through the electrode extraction hole 221. The central axis A of the electrode assembly 10 and the axis of the electrode extraction hole 221 may or may not overlap. In other embodiments, the central axis A may not pass through the electrode extraction hole 221.

[0125] The electrode terminal 30 is fitted into the electrode lead-out hole 221 and is used to cover the electrode lead-out hole 221. The electrode terminal 30 may or may not fit into the electrode lead-out hole 221. The electrode terminal 30 is fixed to the lid 22. The electrode terminal 30 may be fixed entirely to the outside of the lid 22, or may fit into the inside of the case 20 via the electrode lead-out hole 221.

[0126] In some embodiments, the cylinder 21 is a cylinder and the cover 22 is a circular plate-like structure. In other embodiments, the cylinder 21 may be a rectangular cylinder and the cover 22 may be a square plate-like structure.

[0127] In some embodiments, the cover 22 and the cylindrical body 21 are integrally molded, thereby eliminating the need for a process for connecting the cover 22 and the cylindrical body 21.

[0128] When the cover 22 and the cylindrical body 21 are electrically connected to the positive or negative electrode of the electrode assembly 10, the connection between the cover 22 and the cylindrical body 21 has an integral structure, so the resistance at the connection between the cover 22 and the cylindrical body 21 is relatively low, thereby improving the overcurrent capability. The cover 22 may also be used to connect to an external component (e.g., a busbar member). If the battery cell is subjected to an external impact, the external component may pull the cover 22, exerting force on the connection between the cover 22 and the cylindrical body 21. The above technical solution installs the cover 22 and the cylindrical body 21 as a single unit, thereby improving the strength of the connection between the cover 22 and the cylindrical body 21 and reducing the risk of the connection between the cover 22 and the cylindrical body 21 becoming weak.

[0129] In some embodiments, the case 20 may be formed by a drawing process.

[0130] In some embodiments, the cylindrical body 21 has an opening 211 at the end away from the lid body 22 , and the battery cell 7 further includes a cover plate 50 for sealing the opening 211 .

[0131] The cover plate 50 is placed over the opening of the cylindrical body 21 to seal the opening of the cylindrical body 21. The cover plate 50 may have various structures, for example, the cover plate 50 has a plate-like structure.

[0132] In some embodiments, the cover plate 50 may be a circular cover plate, a rectangular cover plate, a square cover plate, a hexagonal cover plate, or a cover plate of other shapes.

[0133] In some embodiments, the cover plate 50 is welded to the barrel 21 .

[0134] In some embodiments, the cover 22 is circular, the electrode assembly 10 is cylindrical, and the central axis A overlaps with the axis of the electrode lead hole 221. This embodiment does not require that the central axis A and the axis of the electrode lead hole 221 overlap perfectly, and there may be variations between them that are allowable in the process.

[0135] In this embodiment, the electrode extraction holes 221 are opened approximately in the center of the lid 22, and accordingly, the electrode terminals 30 are also attached to the center of the lid 22. When assembling multiple battery cells 7 into sets, the requirements for positioning accuracy of the electrode terminals 30 are reduced, and the assembly process can be simplified.

[0136] For example, the axis of the electrode lead-out hole 221 and the axis of the lid 22 are aligned, and the lid 22 has a ring-shaped structure that is disposed around the axis of the electrode lead-out hole 221 .

[0137] For example, the axis of the electrode terminal 30 and the axis of the electrode lead-out hole 221 are aligned with each other.

[0138] In other embodiments, the lid 22 may be rectangular, and the electrode assembly 10 may be flat. The electrode extraction hole 221 may be located near an end of the lid 22 along its longitudinal direction.

[0139] In some embodiments, the axis of the first through-hole 323 and the axis of the electrode lead-out hole 221 are aligned.

[0140] In some embodiments, the electrode assembly 10 further includes a second tab 13, which is opposite in polarity to the first tab 11, and the second tab 13 is electrically connected to the lid 22.

[0141] The cover 22 itself serves as one output electrode of the battery cell 7, thereby eliminating one conventional electrode terminal 30 and simplifying the structure of the battery cell 7. When assembling multiple battery cells 7 into a set, the cover 22 may be electrically connected to a bus bar member, which not only increases the overcurrent area but also allows for more flexibility in the structural design of the bus bar member.

[0142] In some embodiments, the barrel 21 is used to connect the second tab 13 to the lid 22 such that the second tab 13 is electrically connected to the lid 22 .

[0143] The cylindrical body 21 may be electrically connected to the second tab 13 directly, or may be electrically connected to the second tab 13 by another component. For example, the second tab 13 may be electrically connected to the cylindrical body 21 by a cover plate 50.

[0144] The cover 22 and the electrode terminal 30 have opposite polarities. In this case, one of the cover 22 and the electrode terminal 30 may be the positive output terminal of the battery cell 7, and the other may be the negative output terminal of the battery cell 7. In this embodiment, the positive output terminal and the negative output terminal are installed on the same side of the battery cell 7, which simplifies the connection process between multiple battery cells 7.

[0145] The cover 22 may be used for electrical connection to the busbar members. The inventors previously attempted to create first through holes in the cover, but the first through holes reduced the connection area between the cover and the busbar members, reducing the overcurrent area between the cover and the busbar members, making it difficult to meet the battery cell's requirements for overcurrent capacity and temperature rise during rapid charging. Therefore, the inventors created first through holes 323 for electrolyte injection in the electrode terminals 30 to increase the connection area between the cover 22 and the busbar members.

[0146] In some embodiments, the first tab 11 is located at the end of the electrode assembly 10 facing the electrode terminal 30 , and the second tab 13 is located at the end of the electrode assembly 10 facing away from the electrode terminal 30 .

[0147] By providing the first tab 11 and the second tab 13 at opposite ends of the electrode assembly 10, the pitch between the first tab 11 and the second tab 13 can be increased, reducing the risk of the first tab 11 and the second tab 13 becoming electrically connected, thereby improving safety.

[0148] In some embodiments, the second tab 13 is a negative electrode tab and the substrate material of the case 20 is steel. The substrate material is the primary component in the material composition of the case 20.

[0149] The case 20 is electrically connected to the negative electrode tab, i.e., the case 20 is in a low potential state. The steel case 20 is not easily corroded by the electrolyte in a low potential state.

[0150] The electrode extraction holes 221 in the embodiment of the present application are formed after the case 20 is stretch-molded.

[0151] The inventors previously attempted to roll-press the open end of a cylindrical body, folding it inward to form a burring structure, which then pressed against a cover plate to secure it in place. The inventors then attached electrode terminals to the cover plate, and the burring structure and the electrode terminals formed the two output poles of the battery cell. However, the larger the burring structure, the greater the risk of curling and wrinkling after forming. If the burring structure curls and wrinkles, the surface of the burring structure will become uneven, resulting in welding defects when the burring structure is welded to an external busbar component. Therefore, the size of the burring structure is relatively limited, which can lead to insufficient overcurrent capacity of the battery cell.

[0152] In this embodiment, electrode lead-out holes 221 for attaching electrode terminals 30 are formed in the lid 22 using a hole-punching process, and the positive and negative output electrodes are installed at the ends of the battery cells 7 that are farther from the openings in the cylindrical body 21. The lid 22 is formed during the molding process of the case 20, so that flatness can be ensured even after the electrode lead-out holes 221 are drilled, ensuring the connection strength between the lid 22 and the busbar members. At the same time, because the flatness of the lid 22 is not limited by its own size, the lid 22 can be relatively large, thereby improving the overcurrent capability of the battery cells 7.

[0153] In some embodiments, the electrode terminal 30 achieves electrical connection with the first tab 11 by at least one first weld W1.

[0154] The electrode terminal 30 is welded to another member to form a first weld W1, which conducts current between the electrode terminal 30 and the first tab 11.

[0155] In some examples, the electrode terminal 30 can be directly welded to the first tab 11 to form the first weld W1. For example, a portion of the electrode terminal 30 and a portion of the first tab 11 melt to form a molten pool, and the first weld W1 is formed after the molten pool solidifies.

[0156] In some other alternative examples, the electrode terminal 30 is welded to another member (e.g., a current collecting part described later) connected to the first tab 11 to form a first weld W1. For example, a part of the electrode terminal 30 and a part of the current collecting part melt to form a molten pool, and the first weld W1 is formed after the molten pool solidifies.

[0157] The embodiment of the present application does not particularly limit the shape, position, depth, and number of the first weld W1. For example, the shape of the first weld W1 may be linear, circular, spiral, V-shaped, or other shapes. The first weld W1 may be one or more.

[0158] The first welded portion W1 can reduce the resistance between the electrode terminal 30 and the first tab 11 and improve the overcurrent capability.

[0159] FIG. 8 is a schematic diagram of an electrode terminal of a battery cell according to some embodiments of the present application, FIG. 9 is an enlarged schematic diagram of the circled box C in FIG. 7, and FIG. 10 is a schematic diagram of a terminal body of an electrode terminal of a battery cell according to some embodiments of the present application.

[0160] Referring also to Figures 6 to 10, in some embodiments, the electrode terminal 30 includes a seal plate 33 and a terminal body 34, the terminal body 34 has a first through hole 323, and the seal plate 33 is connected to the terminal body 34 and is used to seal the first through hole 323.

[0161] After the process related to the first through hole 323 is completed, the seal plate 33 is connected to the terminal body 34 to reduce the risk of electrolyte leakage through the first through hole 323 and improve the sealing performance.

[0162] In some embodiments, the terminal body 34 includes a recess 31 and a connecting portion 32 located on the side of the recess 31 facing the electrode assembly 10, the first through-hole 323 passing through the connecting portion 32, and the connecting portion 32 achieving electrical connection with the first tab 11 by at least one first weld W1. At least a portion of the seal plate 33 is received in the recess 31.

[0163] The recess 31 can be recessed in a direction from the side of the terminal body 34 away from the electrode assembly 10 toward the electrode assembly 10. The connection portion 32 is a portion corresponding to the bottom surface of the recess 31 of the terminal body 34.

[0164] The seal plate 33 may be entirely or partially housed within the recess 31 as long as the seal plate 33 can seal the first through-hole 323 .

[0165] The connection portion 32 is welded to another member to form a first weld W1. For example, the welding equipment irradiates a laser onto the surface of the connection portion 32 facing the recess 31, and the laser melts a part of the connection portion 32 and a part of the member located inside the connection portion 32 to form a molten pool, and the first weld W1 can be formed after the molten pool solidifies.

[0166] In the embodiment of the present application, by opening the recess 31 in the terminal body 34, the thickness of the connection portion 32 is reduced, thereby reducing the welding power required for welding, reducing the risk of burning other components, and improving safety. The recess 31 provides a housing space for the seal plate 33, thereby reducing the size of the seal plate 33 protruding from the terminal body 34, reducing the space occupied by the electrode terminal 30, and improving the energy density of the battery cell 7.

[0167] The sealing plate 33 protects the connection portion 32 from the outside, reduces external impurities entering the first recess 31, reduces the risk of the connection portion 32 being damaged by external impurities, and improves the sealing performance of the battery cell 7.

[0168] In some embodiments, the thickness of the connection portion 32 is between 0.5 mm and 10 mm.

[0169] In some embodiments, a gap is provided between the seal plate 33 and the connection portion 32 to avoid the first weld W1.

[0170] If the surface of the first weld W1 is uneven and the seal plate 33 is pressed against the first weld W1, the seal plate 33 will rattle during assembly, affecting the sealing effect. In this embodiment, a gap is provided between the seal plate 33 and the connection part 32, allowing the seal plate 33 to avoid the first weld W1 and preventing direct contact between the seal plate 33 and the first weld W1, thereby reducing rattle of the seal plate 33 during assembly and ensuring the sealing effect.

[0171] In some embodiments, a step surface 311 is provided on the side wall of the recess 31, at least a portion of the seal plate 33 is accommodated in the recess 31, and the step surface 311 is used to support the seal plate 33.

[0172] The recess 31 is a stepped recess that is larger on the outside and smaller on the inside.

[0173] When assembling the seal plate 33, the step surface 311 supports and positions the seal plate 33, thereby simplifying the assembly process and forming a gap between the seal plate 33 and the connecting portion 32.

[0174] In some embodiments, the seal plate 33 is welded to the sidewall of the recess 31 to seal the opening of the recess 31 and the first through-hole 323 .

[0175] In some embodiments, the connecting portion 32 is provided with a recessed groove 324 recessed along a direction from the first outer surface 322 of the connecting portion 32 toward the electrode assembly 10 .

[0176] The connecting portion 32 has a first outer surface 322 and a first inner surface 321 arranged opposite to each other along the thickness direction of the connecting portion 32, with the first inner surface 321 facing the electrode assembly 10 and the first outer surface 322 facing away from the electrode assembly 10. Optionally, both the first outer surface 322 and the first inner surface 321 are flat. The groove 324 is recessed in the first outer surface 322 in the direction toward the electrode assembly 10.

[0177] The portion between the bottom wall of the recessed groove 324 and the first inner surface 321 is welded to another member and is used to form a first welded portion W1.

[0178] In this embodiment, a groove 324 is formed in the connecting portion 32, thereby forming a stepped structure in the connecting portion 32. A gap is formed between the first outer surface 322 and the bottom wall of the groove 324.

[0179] During the production process of the battery cell 7, an external device needs to be fitted to the connection portion 32. The surface of the first weld W1 is uneven, and if the external device is pressed against the first weld W1, the external device is likely to be crushed by the first weld W1. In this embodiment, the groove 324 is provided to form a gap between the first outer surface 322 and the bottom wall of the groove 324. In this way, the first outer surface 322 can be used to support the external device, separating the external device from the first weld W1 and reducing the risk of the external device being crushed.

[0180] For example, the external equipment may be a liquid injection equipment, an air extraction equipment, a welding equipment, or other equipment used for the battery cell 7.

[0181] For example, during injection, the injection head is pressed against the first outer surface 322, which supports the injection head and fits into the injection head to achieve a seal, thereby reducing the risk of electrolyte leaking outside the battery cell 7.

[0182] In some embodiments, the terminal body 34 has an opposing second outer surface 344 and a second inner surface 345. The second inner surface 345 faces toward the electrode assembly 10, and the second outer surface 344 faces away from the electrode assembly 10. The recess 31 is recessed from the second outer surface 344 toward the electrode assembly 10 to the first outer surface 322 of the connecting portion 32.

[0183] In some embodiments, the seal plate 33 may be used to be welded to a bus bar member of a battery, which may connect the seal plate 33 of one battery cell 7 to the lid 22 of another battery cell 7, connecting the two battery cells 7 in series.

[0184] In some embodiments, at least a portion of seal plate 33 protrudes from second outer surface 344 of terminal body 34 .

[0185] When it is necessary to weld the busbar member and the seal plate 33, first, the busbar member is attached to the upper surface of the seal plate 33 (i.e., the outer surface of the seal plate 33 facing away from the connection portion 32), and then the busbar member and the seal plate 33 are welded together.

[0186] At least a portion of the seal plate 33 protrudes from the second outer surface 344, thereby preventing the second outer surface 344 from interfering with the bonding of the seal plate 33 and the bus bar member, and ensuring that the bus bar member is tightly attached to the seal plate 33.

[0187] In some embodiments, the connection portion 32 is located at the end of the terminal body 34 that faces the electrode assembly 10. , and the first inner surface 321 of the connecting portion 32 is set flush with the second inner surface 345 .

[0188] The second inner surface 345 is the surface of the terminal body 34 facing the electrode assembly 10. The first inner surface 321 of the connecting portion 32 forms part of the second inner surface 345. In this manner, the terminal body 34 can be fitted to a current collecting component having a flat structure. In this embodiment, simply by attaching the current collecting component to the second inner surface 345, the connecting portion 32 and the current collecting component can be attached to each other, and welding of the connecting portion 32 and the current collecting component can be easily achieved.

[0189] In some embodiments, the terminal body 34 includes a columnar portion 341, a first stopper portion 342, and a second stopper portion 343, at least a portion of the columnar portion 341 is located within the electrode extraction hole 221, the recess 31 is provided in the columnar portion 341, the first stopper portion 342 and the second stopper portion 343 are both connected to the outer wall of the columnar portion 341 and protrude from the outer wall of the columnar portion 341, and the first stopper portion 342 and the second stopper portion 343 are provided on the outside and inside of the lid body 22, respectively, and are used to clamp a portion of the lid body 22.

[0190] Providing the first stopper portion 342 on the outside of the lid body 22 means that the first stopper portion 342 is provided on the side of the lid body 22 that faces away from the electrode assembly 10, and providing the second stopper portion 343 on the inside of the lid body 22 means that the second stopper portion 343 is provided on the side of the lid body 22 that faces toward the electrode assembly 10.

[0191] In the thickness direction of the lid body 22, at least a portion of the first stopper portion 342 overlaps with the lid body 22, and at least a portion of the second stopper portion 343 overlaps with the lid body 22. The columnar portion 341 passes through the electrode lead-out hole 221 and connects the first stopper portion 342 and the second stopper portion 343, which are located on both sides of the lid body 22, respectively.

[0192] The first stopper portion 342 and the second stopper portion 343 sandwich a portion of the lid body 22 from both sides to fix the terminal body 34 to the lid body 22. The first stopper portion 342 and the second stopper portion 343 may directly sandwich the lid body 22, or may indirectly sandwich the lid body 22 by another component.

[0193] Optionally, the columnar portion 341 is cylindrical. The first stopper portion 342 and the second stopper portion 343 are both ring-shaped structures that surround the columnar portion 341.

[0194] In some embodiments, the battery cell 7 further includes a first insulating part 60 and a second insulating part 70, where at least a portion of the first insulating part 60 is provided between the first stopper part 342 and the lid body 22, and at least a portion of the second insulating part 70 is provided between the second stopper part 343 and the lid body 22. The first insulating part 60 and the second insulating part 70 are used to insulate and separate the terminal body 34 and the lid body 22.

[0195] The first insulating component 60 and the second insulating component 70 each have a ring-shaped structure that is disposed so as to surround the columnar portion 341 .

[0196] The first insulating part 60 can insulate and separate the first stopper part 342 and the lid body 22 , and the second insulating part 70 can insulate and separate the second stopper part 343 and the lid body 22 .

[0197] In some embodiments, one of the first insulating part 60 and the second insulating part 70 separates the columnar part 341 from the cover 22. For example, a part of the first insulating part 60 extends into the electrode lead-out hole 221 and separates the wall of the electrode lead-out hole 221 from the columnar part 341.

[0198] In some embodiments, the first insulating component 60 and the second insulating component 70 are integrally formed structures. Alternatively, in other embodiments, the first insulating component 60 and the second insulating component 70 are provided separately and abut each other.

[0199] In some embodiments, one of the first insulating part 60 and the second insulating part 70 is used to seal the electrode drawing hole 221. In some examples, the first stopper part 342 and the cover 22 push out the first insulating part 60, and the first insulating part 60 is compressed to seal the electrode drawing hole 221 from the outside. In other examples, the second stopper part 343 and the cover 22 push out the second insulating part 70, and the second insulating part 70 is compressed to seal the electrode drawing hole 221 from the inside.

[0200] In some embodiments, the battery cell 7 further includes a seal ring 80, which is fitted onto the columnar portion 341 and is used to seal the electrode lead-out hole 221. Optionally, a portion of the seal ring 80 extends into the electrode lead-out hole 221 and separates the wall of the electrode lead-out hole 221 from the columnar portion 341.

[0201] In some embodiments, the first stopper portion 342 has a plurality of protruding structures 342a on its outer periphery, and the protruding structures 342a are spaced apart along the circumferential direction of the columnar portion 341.

[0202] Alternatively, the plurality of protruding structures 342a may be arranged at intervals along the circumferential direction of the columnar portion 341, for example.

[0203] The first stopper portion 342 has a burring structure formed by folding back the end portion of the terminal body 34 that is away from the electrode assembly 10 outward.

[0204] Before assembling the terminal body 34 to the case 20, the first stopper portion 342 of the terminal body 34 has a substantially cylindrical structure and is located at the upper end of the columnar portion 341, and the outer wall of the first stopper portion 342 is flush with the outer wall of the columnar portion 341. When assembling the terminal body 34 to the case 20, after the first stopper portion 342 passes through the electrode pull-out hole 221, the first stopper portion 342 is pushed out, whereby the first stopper portion 342 is folded back outward and the terminal body 34 is crimped to the lid 22.

[0205] Before folding back the first stopper portion 342, a plurality of spaced apart groove structures 342b are formed on the upper end of the first stopper portion 342, and after folding back the first stopper portion 342, a plurality of spaced apart protrusion structures 342a are formed around the columnar portion 341, with groove structures 342b between adjacent protrusion structures 342a. In this embodiment, the provision of the groove structures 342b and the protrusion structures 342a makes it easier to fold back the first stopper portion 342 and reduces stress concentration on the first stopper portion 342.

[0206] In some embodiments, the second stopper portion 343 is a stopper structure formed by pushing out the end of the terminal body 34 facing the electrode assembly 10, causing the end of the terminal body 34 facing the electrode assembly 10 to extend outward. When assembling the cover 22 and the terminal body 34, an external device can push out the end of the terminal body 34 facing the electrode assembly 10, and the end of the terminal body 34 facing the electrode assembly 10 extends outward due to the action of pressure, forming the protruding second stopper portion 343.

[0207] In some embodiments, the battery cell 7 further includes a current collecting component 40 for electrically connecting the electrode terminal 30 and the first tab 11 .

[0208] The current collecting element 40 electrically connects the first tab 11 to the electrode terminal 30. The embodiments of the present application do not limit the manner of connection between the first tab 11 and the current collecting element 40, and for example, the current collecting element 40 may be connected to the first tab 11 by welding, abutting, adhesive, or the like.

[0209] The current collecting member 40 is welded to the electrode terminal 30 to form at least one first weld W1.

[0210] For example, the current collecting part 40 is welded to the connection part 32 to form at least one first weld part W1. When the connection part 32 and the current collecting part 40 are welded, the first through hole 323 serves to release welding stress, thereby reducing the risk of the connection part 32 bursting.

[0211] In some embodiments, the first weld W1 extends in the thickness direction of the connection portion 32 from the side of the connection portion 32 facing away from the current collecting element 40 to at least the interior of the current collecting element 40 .

[0212] During welding, for example, after the electrode assembly 10 and the current collecting member 40 are mounted in the case 20 and the current collecting member 40 is pressed against the connecting portion 32, an external welding device can weld the connecting portion 32 and the current collecting member 40 from the side of the connecting portion 32 that faces away from the current collecting member 40 to form a first weld W1. The first weld W1 is exposed on the surface of the connecting portion 32 that faces away from the current collecting member 40.

[0213] The first weld W1 can penetrate the current collecting element 40, for example, the first weld W1 penetrates between the current collecting element 40 and the connection portion 32, and the first weld W1 is exposed on a surface of the current collecting element 40 that is away from the connection portion 32. Of course, the first weld W1 does not have to penetrate the current collecting element 40, that is, the first weld W1 is not exposed on a surface of the current collecting element 40 that is away from the connection portion 32.

[0214] The first weld W1 extends from the connection portion 32 to the inside of the current collecting element 40, connecting the current collecting element 40 and the connection portion 32, reducing the contact resistance between the current collecting element 40 and the electrode terminal 30 and improving the overcurrent capability.

[0215] In some embodiments, the first weld W1 does not extend beyond the surface of the current collecting element 40 that faces away from the connection portion 32 in the thickness direction of the connection portion 32 .

[0216] A predetermined distance is maintained between the first weld W1 and the surface of the current collecting element 40 that faces away from the connection portion 32 to prevent the current collecting element 40 from melting, reduce the risk of metal particles being generated on the surface of the current collecting element 40 that faces away from the connection portion 32, and improve safety.

[0217] In some embodiments, the current collecting piece 40 is welded to the first tab 11 to form a second weld W2.

[0218] When assembling the battery cell 7, the first tab 11 of the electrode assembly 10 is first welded to the current collecting element 40, and then the electrode assembly 10 and the current collecting element 40 are placed inside the case 20. Specifically, when welding the first tab 11 to the current collecting element 40, the current collecting element 40 is first pressed against the end surface of the first tab 11 that has been flattened after being rolled, and then an external welding device emits a laser onto the surface of the current collecting element 40 that faces away from the first tab 11, and the laser welds the current collecting element 40 to the first tab 11.

[0219] The shape of the second weld W2 may be linear, C-shaped, annular, spiral, V-shaped, or other shapes. The second welded portion W2 may be one or more, and this embodiment does not limit this.

[0220] The second weld W2 can reduce the contact resistance between the current collecting part 40 and the first tab 11 and improve the overcurrent capability.

[0221] In some embodiments, the current collecting piece 40 has a protrusion 41 on the side facing the first tab 11, and the protrusion 41 is welded to the first tab 11 to form a second weld W2.

[0222] When assembling the current collecting part 40 and the electrode assembly 10, first, the protrusion 41 of the current collecting part 40 is pressed onto the first tab 11, and then the protrusion 41 and the first tab 11 are welded together. The protrusion 41 is better attached to the first tab 11, which reduces the risk of welding defects.

[0223] In some embodiments, the protrusion 41 can be extruded from and integrated into the first tab 11 .

[0224] In some embodiments, other than the protrusions 41, the remainder of the current collecting element 40 is of a generally flat structure.

[0225] In some embodiments, a recessed structure 44 is formed at a position corresponding to the protrusion 41 of the current collecting element 40, and the recessed structure 44 is recessed in a direction toward the first tab 11 with respect to a surface of the current collecting element 40 away from the first tab 11. An adapter portion is formed between the bottom surface of the recessed structure 44 and the top surface of the protrusion 41, and the adapter portion is welded to the first tab 11 to form a second welded portion W2. By providing the recessed structure 44, the thickness of the adapter portion can be reduced, which reduces the welding power required to weld the adapter portion and the first tab 11, reduces heat generation, and reduces the risk of the electrode assembly 10 being burned.

[0226] The second welded portion W2 is formed by welding and has an uneven surface. In this embodiment, by providing a recessed structure 44, the surface of the second welded portion W2 is recessed relative to the surface of the current collecting element 40 that faces away from the first tab 11, so that the second welded portion W2 can avoid contact with other components (e.g., the electrode terminal 30).

[0227] In some embodiments, the number of the first welds W1 is one, and the first welds W1 extend along the circumferential direction Y of the first through hole 323 and surround at least a portion of the first through hole 323.

[0228] The first weld W1 may have a ring-shaped or semi-ring-shaped structure. The size of the first weld W1 extending along the circumferential direction Y may be determined according to the overcurrent capability requirements of the battery cell 7, and is not particularly limited in this embodiment.

[0229] The first welded portion W1 increases the strength of the region of the electrode terminal 30 located around the first through-hole 323, and can reduce deformation of the electrode terminal 30 due to impact from the electrolyte.

[0230] In some embodiments, the first weld W1 surrounds only a portion of the first through hole 323 along the circumferential direction Y of the first through hole 323.

[0231] A portion of the first through hole 323 is surrounded by the first weld W1 along the circumferential direction Y of the first through hole 323, and another portion of the first through hole 323 is surrounded by the first weld W1 along the circumferential direction Y of the first through hole 323.

[0232] The outer periphery of the first through hole 323 is not sealed by the first weld W1, and the gap between the electrode terminal 30 and the member welded to the electrode terminal 30 (e.g., the current collecting part 40) is not blocked by the first weld W1, so that some of the electrolyte flowing in through the first through hole 323 passes through this gap, thereby increasing the efficiency of injecting the electrolyte.

[0233] In some embodiments, the angle that the first weld W1 surrounds the first through hole 323 is α, where 180°≦α≦360°.

[0234] Alternatively, α may be 180°, 225°, 270°, 315° or 360°.

[0235] α has a positive correlation with the overcurrent area of ​​the first weld W1. The smaller α, the smaller the overcurrent area of ​​the first weld W1, and the greater the heat generated when current flows through the first weld W1. In the embodiment of the present application, α satisfies 180°≦α≦360°, so that the first weld W1 meets the overcurrent capacity and temperature rise requirements of the battery cell 7.

[0236] FIG. 11 is a schematic diagram of a terminal body of an electrode terminal of a battery cell according to some other embodiments of the present application.

[0237] As shown in FIG. 11, in some embodiments, the first weld W1 surrounds the entire circumference of the first through hole 323, ie, α is 360°.

[0238] The embodiment of the present application increases the overcurrent area of ​​the first weld W1, allowing the first weld W1 to meet the requirements of the battery cell 7 for overcurrent capacity and temperature rise, increasing the strength of the first weld W1, and reducing the risk of the first weld W1 being torn when the battery cell 7 vibrates.

[0239] FIG. 12 is a schematic diagram of a terminal body of an electrode terminal of a battery cell according to still some embodiments of the present application.

[0240] Referring to Figures 6 to 9 and Figure 12 together, in some embodiments, the first welds W1 are multiple, and the multiple first welds W1 are spaced apart along the circumferential direction Y of the first through hole 323.

[0241] The first welded portion W1 may extend along the circumferential direction Y of the first through hole 323, or may extend along the radial direction of the first through hole 323.

[0242] In this embodiment, there are no particular limitations on the angular spacing between two adjacent first welds W1 in the circumferential direction Y of the first through hole 323. The multiple first welds W1 may be arranged at equal intervals or at unequal intervals along the circumferential direction Y of the first through hole 323.

[0243] Assuming that the total area is constant, compared with the method of installing one first weld W1, the method of installing multiple first welds W1 can reduce the welding power per welding and reduce heat generation.

[0244] In some embodiments, the interval angle β between the first through holes 323 of any two adjacent first welds W1 along the circumferential direction Y is less than 30°.

[0245] The larger the value of angle β, the sparser the distribution of the multiple first welds W1 and the smaller the total overcurrent area of ​​the multiple first welds W1, and the smaller the value of angle β, the denser the distribution of the multiple first welds W1 and the larger the total overcurrent area of ​​the multiple first welds W1. In the embodiment of the present application, β is limited to less than 30° to meet the requirements of the battery cell 7 for overcurrent capacity and temperature rise and reduce the risk of the first welds W1 being torn when the battery cell 7 vibrates.

[0246] In some embodiments, each first weld W1 extends along the radial direction of the first through hole 323.

[0247] The first weld W1 extending radially of the first through hole 323 means that the size of the first weld W1 along the radial direction of the first through hole 323 is larger than the size of the first weld W1 along the circumferential direction Y of the first through hole 323.

[0248] The first weld W1 extends radially of the first through hole 323, and the size of the first weld W1 along the circumferential direction Y of the first through hole 323 can be reduced. By arranging more first welds W1 around the outer periphery of the first through hole 323, the electrode terminal 30 can increase its overcurrent capacity and reduce heat generation.

[0249] In some embodiments, the depth of the first weld W1 in the axial direction X of the first through hole 323 is h, and the minimum pitch between the first weld W1 and the first through hole 323 in the radial direction of the first through hole 323 is d, where d and h satisfy 0.1≦h / d≦0.6.

[0250] Due to process tolerances, different regions of the first weld W1 may have different penetrations in the axial direction X of the first through hole 323. h may be the size along the axial direction X of the first through hole 323 of the region with the least penetration of the first weld W1.

[0251] The larger h is, the greater the power required for welding, the greater the heat generated during the welding process, the greater the thermal stress acting on the area close to the first through hole 323, and the greater the degree of deformation of the first through hole 323. The smaller d is, the greater the amount of heat conducted to the area close to the first through hole 323 during the welding process, the greater the thermal stress acting on the area close to the first through hole 323, and the greater the degree of deformation of the first through hole 323. If h / d is too large, the first through hole 323 will deform significantly, making it difficult for the injection head to fit into the first through hole 323 and affecting injection efficiency. After extensive research and experimentation, the inventors found that by limiting the value of h / d to 0.6 or less, the thermal stress acting on the area close to the first through hole 323 will be reduced, reducing the deformation of the first through hole 323 and making it easier for the injection head to fit into the first through hole 323.

[0252] The smaller h is, the lower the overcurrent capacity and strength of the first weld W1, and the higher the risk of the first weld W1 tearing when the battery cell 7 vibrates. The larger d is, the smaller the area available for welding the electrode terminal 30, limiting the overcurrent capacity and strength of the first weld W1. If h / d is too small, the overcurrent capacity and strength of the first weld W1 will be insufficient. After extensive research and experimentation, the inventors have found that the overcurrent capacity and strength of the first weld W1 can be met by limiting the value of h / d to 0.1 or greater.

[0253] Alternatively, the value of h / d may be 0.1, 0.2, 0.3, 0.4, 0.5 or 0.6.

[0254] In some embodiments, d and h satisfy the relationship 0.2≦h / d≦0.5. After extensive research and experimentation, the inventors have found that when 0.2≦h / d≦0.5, the deformation of the first through hole 323 can be effectively reduced, and the overcurrent capacity and strength of the first weld W1 can meet the requirements.

[0255] In some embodiments, 1.6 mm≦d≦5.5 mm.

[0256] If d is too small, too much heat is conducted to the area near the first through hole 323 during the welding process, the thermal stress acting on the area near the first through hole 323 is too large, the first through hole 323 is significantly deformed, and the injection head is difficult to fit into the first through hole 323, affecting the injection efficiency. If d is too large, the area available for welding the electrode terminal 30 is small, and the overcurrent capacity and strength of the first weld W1 are insufficient.

[0257] After extensive research and experimentation, the inventors have found that by limiting the value of d to 1.6 mm to 5.5 mm, the deformation of the first through hole 323 can be reduced, the injection head can be easily fitted into the first through hole 323, and the overcurrent capacity and strength of the first weld W1 can meet the requirements.

[0258] Optionally, d is 1.6 mm, 2 mm, 3 mm, 4 mm, 5 mm or 5.5 mm.

[0259] In some embodiments, h is between 0.8 mm and 1.0 mm.

[0260] In some embodiments, the electrode assembly 10 has a wound structure, and the electrode assembly 10 has a second through-hole 14 at the center of the winding. The first through-hole 323 communicates with the second through-hole 14 so that the electrolyte injected through the first through-hole 323 can flow into the second through-hole 14.

[0261] For example, the electrode assembly 10 is produced by winding a first electrode plate, a second electrode plate, and a separator around a winding tool, and after winding, the winding tool is removed from the electrode assembly 10. After the winding tool is removed, a second through-hole 14 is formed in the center of the electrode assembly 10. The second through-hole 14 passes through the first tab 11, the main body 12, and the second tab 13.

[0262] In the axial direction X of the first through hole 323, the first through hole 323 and the second through hole 14 may or may not overlap.

[0263] In the embodiment of the present application, the size relationship between the diameter of the first through-hole 323 and the diameter of the second through-hole 14 is not particularly limited.

[0264] In the liquid injection process, the electrolyte can flow into the second through hole 14 through the first through hole 323, and the electrolyte flowing into the second through hole 14 can infiltrate the electrode assembly 10 from the inside, thereby improving the infiltration efficiency of the electrode assembly 10.

[0265] In some embodiments, the axial direction X of the first through-hole 323 is parallel to the axial direction of the second through-hole 14 .

[0266] In some embodiments, the projection of the first through hole 323 at least partially overlaps with the projection of the second through hole 14 in the axial direction X of the first through hole 323 .

[0267] The first through hole 323 and the second through hole 14 face each other along the axial direction X of the first through hole 323, and a portion of the electrolyte passing through the first through hole 323 enters the second through hole 14 without changing its flow, thereby improving the infiltration efficiency of the electrode assembly 10.

[0268] Alternatively, when the first through hole 323 is a diameter-changing hole, the projection of the first through hole 323 along its own axial direction X is a projection of an opening at an inner end of the first through hole 323 along its own axial direction X. When the second through hole 14 is a diameter-changing hole, the projection of the second through hole 14 along the axial direction X of the first through hole 323 is a projection of an opening at an end of the second through hole 14 closer to the first through hole 323 along the axial direction X of the first through hole 323.

[0269] In some embodiments, the projection of the second through hole 14 in the axial direction X of the first through hole 323 is larger than the projection of the first through hole 323 .

[0270] The area of ​​the first through hole 323 projected along its own axial direction X is S1, and the area of ​​the second through hole 14 projected along the axial direction X of the first through hole 323 is S2, and S2 is greater than S1.

[0271] Compared with the first through hole 323, the second through hole 14 has a relatively larger cross-sectional area, and thus the second through hole 14 can accommodate more electrolyte and contribute to improving the efficiency with which the electrolyte infiltrates the electrode assembly 10 from the inside.

[0272] In some embodiments, in the axial direction X of the first through-hole 323, the projection of the first through-hole 323 lies within the projection of the second through-hole 14.

[0273] According to this embodiment, the entity portion of the electrode assembly 10 can avoid the first through-hole 323, reducing the amount of electrolyte that directly impacts the electrode assembly 10 and reducing the risk of deformation of the electrode assembly 10. For example, the embodiment of the present application can reduce the impact received by the first tab 11 and the separator, and reduce deformation of the first tab 11 and the separator.

[0274] In some embodiments, the diameter of the first through-holes 323 is D1, the diameter of the second through-holes 14 is D2, and D1 and D2 satisfy 65%≦D1 / D2≦95%.

[0275] Illustratively, D1 is the minimum diameter of the first through-hole 323, and D2 is the minimum diameter of the second through-hole 14.

[0276] The larger D1 is, the higher the efficiency of electrolyte injection, the shorter the time until the electrolyte is filled, the less electrolyte can infiltrate the electrode assembly 10 during the injection process, and the smaller the total amount of electrolyte injected. The smaller D2 is, the smaller the wall area of ​​the second through-hole 14 is, and the less efficiently the electrolyte infiltrates from the inside of the electrode assembly 10. If D1 / D2 is too large, the amount of electrolyte injected will be small, which will affect the cycle life of the battery cell 7. After extensive research and extensive experiments, the inventors have found that the required amount of electrolyte injection can be met by limiting the value of D1 / D2 to 95% or less.

[0277] The smaller D1, the lower the efficiency of electrolyte injection and the longer it takes for the electrolyte to fill the electrode assembly 10. The larger D2, the higher the efficiency of electrolyte infiltration from the inside of the electrode assembly 10. If D1 / D2 is too small, the injection time is long and product production efficiency is low. Furthermore, the larger D2, the smaller the capacity of the electrode assembly 10, the lower the internal space utilization rate of the battery cell 7, and the lower the energy density of the battery cell 7. After extensive research and extensive experiments, the inventors have found that limiting the value of D1 / D2 to 65% or more increases the injection efficiency and reduces the loss of energy density of the battery cell 7 due to the second through-holes 14.

[0278] Alternatively, the value of D1 / D2 may be 65%, 75%, 85% or 95%.

[0279] In some embodiments, D2≧D1+0.2 mm.

[0280] When assembling the battery cell 7, an assembly error may cause the electrode assembly 10 to become misaligned, causing the first through-hole 323 to face the entity portion of the electrode assembly 10, thereby causing the electrode assembly 10 to be impacted by the electrolyte.

[0281] After extensive research and experimentation, the inventors have found that setting D2≧D1+0.2 mm provides a margin of error for the electrode assembly 10, reduces the risk of the entity portion of the electrode assembly 10 facing the first through-hole 323, reduces the amount of electrolyte directly impacting the electrode assembly 10, and reduces the risk of deformation of the electrode assembly 10.

[0282] In some embodiments, the central axis of the first through hole 323 is parallel to the central axis of the second through hole 14. Optionally, the central axis of the first through hole 323 and the central axis of the second through hole 14 overlap. Illustratively, the central axis of the second through hole 14 may be the central axis A of the electrode assembly 10.

[0283] In some embodiments, the battery cell 7 further includes a current collecting member 40 for electrically connecting the electrode terminal 30 and the first tab 11. The current collecting member 40 includes a third through hole 45, and at least a portion of the third through hole 45 is provided between the first through hole 323 and the second through hole 14.

[0284] This embodiment does not particularly limit the diameter of the third through-hole 45, and the diameter may be larger, smaller, or equal to the space of the first through-hole 323.

[0285] In the axial direction X of the first through hole 323, the third through hole 45 faces the first through hole 323, i.e., a projection of the third through hole 45 along the axial direction X of the first through hole 323 at least partially overlaps with a projection of the first through hole 323 along the axial direction X of the first through hole 323. In the axial direction X of the first through hole 323, the third through hole 45 faces the second through hole 14, i.e., a projection of the third through hole 45 along the axial direction X of the first through hole 323 at least partially overlaps with a projection of the second through hole 14 along the axial direction X of the first through hole 323.

[0286] By providing the third through hole 45, the current collecting element 40 avoids the electrolyte flowing in through the first through hole 323, reducing the resistance of the current collecting element 40 to the electrolyte during the injection process, and the electrolyte can smoothly flow into the second through hole 14 through the third through hole 45, thereby improving the infiltration efficiency of the electrode assembly 10.

[0287] In some embodiments, the axial direction of the third through-hole 45 is parallel to the axial direction X of the first through-hole 323 .

[0288] In some embodiments, the diameter of the third through holes 45 is equal to or larger than the diameter of the first through holes 323. The diameter of the third through holes 45 is equal to or smaller than the diameter of the second through holes 14.

[0289] In some embodiments, the projection of the third through hole 45 in the axial direction X of the first through hole 323 is smaller than the projection of the second through hole 14 .

[0290] The area of ​​the third through hole 45 projected along the axial direction X of the first through hole 323 is S3, and S2 is greater than S3. Illustratively, the diameter of the third through hole 45 is smaller than the diameter of the second through hole 14.

[0291] Compared with the third through hole 45, the second through hole 14 has a relatively large cross-sectional area, and thus the electrolyte through the third through hole 45 can quickly flow into the second through hole 14, which can contribute to improving the efficiency of the electrolyte infiltrating into the electrode assembly 10 from the inside.

[0292] In some embodiments, the projection of the third through hole 45 in the axial direction X of the first through hole 323 is larger than the projection of the first through hole 323. Illustratively, the diameter of the third through hole 45 is larger than the diameter of the first through hole 323.

[0293] Compared with the first through hole 323, the third through hole 45 has a relatively larger cross-sectional area, thus reducing the risk of the current collecting element 40 blocking the first through hole 323, and allowing the electrolyte to smoothly enter the second through hole 14 through the third through hole 45, thereby increasing the efficiency with which the electrolyte infiltrates the electrode assembly 10 from the inside.

[0294] In some embodiments, in the axial direction X of the first through-hole 323, the projection of the first through-hole 323 lies within the projection of the third through-hole 45.

[0295] This embodiment can reduce the risk of the current collecting element 40 blocking the first through hole 323, and not only can the electrolyte flow smoothly into the case 20, but also reduce the impact received by the current collecting element 40 and the risk of the connection point between the current collecting element 40 and the electrode terminal 30 being torn.

[0296] In some embodiments, the projection of the third through hole 45 is located within the projection of the second through hole 14 in the axial direction X of the first through hole 323. This embodiment can reduce the shielding of the entity portion of the electrode assembly 10 from the third through hole 45, and the electrolyte can smoothly flow into the second through hole 14.

[0297] In some embodiments, the first through hole 323, the second through hole 14, and the third through hole 45 are arranged coaxially. Arranging them coaxially means that the central axes of the first through hole 323, the second through hole 14, and the third through hole 45 are overlapped. Of course, the overlapping in this embodiment does not require absolute overlapping, and common sense engineering errors are allowed.

[0298] By arranging the three through holes coaxially, the electrolyte can flow in more smoothly and the shock from the electrolyte to the current collecting member 40 and the electrode assembly 10 can be reduced.

[0299] In some embodiments, the diameter of the third through hole 45 is smaller than the diameter of the second through hole 14, and the current collecting element 40 protrudes radially inward of the second through hole 14 beyond the wall of the second through hole 14. The current collecting element 40 shields the first tab 11 and can reduce the impact of the electrolyte on the first tab 11.

[0300] FIG. 13 is a schematic cross-sectional view of a battery cell according to some other embodiments of the present application.

[0301] As shown in FIG. 13, in some embodiments, the electrode terminal 30 is welded to the first tab 11 to form a first weld W1.

[0302] Compared with the battery cell shown in FIG. 6, the battery cell 7 shown in FIG. 13 omits the current collecting components, thereby simplifying the internal structure of the battery cell 7, shortening the conductive path between the electrode terminal 30 and the first tab 11, and increasing the energy density of the battery cell 7.

[0303] According to some embodiments of the present application, there is further provided a battery, the battery including a plurality of the battery cells of any one of the above embodiments.

[0304] FIG. 14 is a schematic local cross-sectional view of a battery cell according to some other embodiments of the present application.

[0305] As shown in Fig. 14, in some embodiments, the recess in the electrode terminal 30 can be omitted. Illustratively, the first through-hole 323 penetrates the terminal body 34, and the terminal body 34 does not need to have the recess 31 shown in Fig. 6. The seal plate 33 may be placed directly on the terminal body 34 to seal the first through-hole 323.

[0306] FIG. 15 is a cross-sectional schematic view of a battery cell according to some further embodiments of the present application.

[0307] As shown in FIG. 15, in some embodiments, the battery cells 7 may be rectangular battery cells.

[0308] In some embodiments, the case 20 includes a cylindrical body 21 and a cover body 22 that are integrally formed, and the cylindrical body 21 is disposed so as to surround the outer periphery of the electrode assembly 10. For example, the cylindrical body 21 may be a rectangular cylinder.

[0309] The cylindrical body 21 has an opening at the end away from the lid body 22, and the cover plate 50 is placed over the opening of the cylindrical body 21 to seal the opening of the cylindrical body 21. For example, the cover plate 50 is welded to the cylindrical body 21.

[0310] In some embodiments, the battery cell further includes a first electrode terminal 30 and a second electrode terminal 90 of opposite polarity, where the first electrode terminal 30 is used to electrically connect to a first tab of the electrode assembly 10 and the second electrode terminal 90 is used to electrically connect to a second tab of the electrode assembly 10.

[0311] In some embodiments, the first electrode terminal 30 and the second electrode terminal 90 are both attached to the lid 22 .

[0312] In a battery, the busbar members are connected to the electrode terminals of multiple battery cells to connect the multiple battery cells in series, parallel, or series-parallel. Both the first electrode terminal 30 and the second electrode terminal 90 may be used to connect to the busbar members.

[0313] When the battery receives an external impact, the busbar member pulls the lid body 22 via the first electrode terminal 30 and the second electrode terminal 90, and a force acts on the connection between the lid body 22 and the cylindrical body 21. If the lid body 22 and the cylindrical body 21 are separate structures, for example, if the lid body 22 and the cylindrical body 21 are connected by welding, the connection between the lid body 22 and the cylindrical body 21 may become loose due to the action of the force. In the embodiment of the present application, the lid body 22 and the cylindrical body 21 are integrally installed, thereby improving the strength of the connection between the lid body 22 and the cylindrical body 21 and reducing the risk of the connection between the lid body 22 and the cylindrical body 21 becoming loose.

[0314] In some embodiments, the case 20 is not electrically connected to the positive terminal of the electrode assembly, nor is it electrically connected to the negative terminal of the electrode assembly. In other words, the case 20 does not become electrically charged.

[0315] In some embodiments, the first tab and the second tab of the electrode assembly 10 are located on the same side of the electrode assembly toward the lid 22 .

[0316] In some embodiments, the first through-hole 323 may be opened in the first electrode terminal 30 .

[0317] According to some embodiments of the present application, there is further provided a power consuming device, the power consuming device including the battery of any one of the above embodiments, the battery being used to provide electrical energy to the power consuming device, and the power consuming device may be any one of the above appliances or systems that use a battery cell.

[0318] Referring to FIGS. 4 to 7 , according to some embodiments of the present application, a cylindrical battery cell 7 is provided, which includes an electrode assembly 10, a case 20, an electrode terminal 30, a current collecting component 40, and a cover plate 50.

[0319] The case 20 includes a cylindrical body 21 and a lid body 22 that are formed integrally. The cylindrical body 21 is disposed so as to surround the outer periphery of the electrode assembly 10, and the lid body 22 is provided with an electrode extraction hole 221. The cylindrical body 21 has an opening 211 at the end that is remote from the lid body 22, and the cover plate 50 is placed over the opening of the cylindrical body 21 to seal the opening of the cylindrical body 21.

[0320] The electrode assembly 10 is housed in a case 20 and includes a main body 12, a first tab 11, and a second tab 13, with the first tab 11 and the second tab 13 protruding from the main body 12. The first tab 11 is located at the end of the electrode assembly 10 facing the electrode terminal 30, and the second tab 13 is located at the end of the electrode assembly 10 facing away from the electrode terminal 30.

[0321] The electrode terminal 30 includes a seal plate 33 and a terminal body 34, the terminal body 34 is attached to the electrode extraction hole 221, the terminal body 34 includes a recess 31 and a connection portion 32 located on the side of the recess 31 facing the electrode assembly 10, and a first through-hole 323 passes through the connection portion 32 and is used to inject an electrolyte into the internal space of the case 20. At least a portion of the seal plate 33 is housed in the recess 31, the seal plate 33 is connected to the terminal body 34, and is used to seal the first through-hole 323.

[0322] The current collecting element 40 is welded to the connection portion 32 to form at least one first weld W1, and the current collecting element 40 is welded to the first tab 11 to form at least one second weld W2, thereby electrically connecting the connection portion 32 and the first tab 11.

[0323] It should be noted that, unless contradictory, the embodiments and features in the embodiments in the present application can be combined with each other.

[0324] Finally, it should be noted that the above examples are only for illustrating the technical solutions of the present application, and are not intended to limit the same. Although the present application has been described in detail with reference to the above examples, those skilled in the art may still modify the technical solutions described in the above examples or make equivalent substitutions for some of the technical features therein, and it should be understood that such modifications or substitutions do not deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell, an electrode assembly including a first tab; a case for housing the electrode assembly; an electrode terminal that is installed in the case, electrically connected to the first tab, and has a first through hole for injecting an electrolyte into the internal space of the case; The electrode assembly has a wound structure, and the electrode assembly has a second through-hole at a wound center portion; the first through-hole communicates with the second through-hole so that an electrolyte solution injected through the first through-hole can flow into the second through-hole; a current collecting part for electrically connecting the electrode terminal and the first tab; The current collecting component includes a third through hole, and at least a portion of the third through hole is provided between the first through hole and the second through hole.

2. The battery cell according to claim 1 , wherein the electrode terminal is electrically connected to the first tab by at least one first welded portion.

3. 3. The battery cell according to claim 2, wherein the number of the first welded portions is one, the first welded portion extends along a circumferential direction of the first through hole, and surrounds at least a portion of the first through hole.

4. The battery cell according to claim 3 , wherein the first welded portion surrounds only a portion of the first through hole along a circumferential direction of the first through hole.

5. The battery cell according to claim 3 , wherein the angle at which the first welded portion surrounds the first through hole is α, and 180°≦α≦360°.

6. The battery cell according to claim 2 , wherein the first welded portion is a plurality of portions, and the plurality of first welded portions are disposed at intervals along the circumferential direction of the first through hole.

7. The battery cell according to claim 6 , wherein an angular interval between any two adjacent first welded portions in the circumferential direction of the first through hole is smaller than 30°.

8. The battery cell according to claim 6 , wherein each of the first welds extends along a radial direction of the first through hole.

9. a depth of the first weld in the axial direction of the first through hole is h, and a minimum pitch between the first weld and the first through hole in the radial direction of the first through hole is d; The battery cell according to claim 2 , wherein d and h satisfy 0.1≦h / d≦0.

6.

10. The battery cell according to claim 9 , wherein d and h satisfy the relationship 0.2≦h / d≦0.

5.

11. The battery cell of claim 9 , wherein 1.6 mm≦d≦5.5 mm.

12. The battery cell according to claim 1 , wherein a projection of the first through hole at least partially overlaps a projection of the second through hole in an axial direction of the first through hole.

13. The battery cell according to claim 1 , wherein a projection of the second through hole in the axial direction of the first through hole is larger than a projection of the first through hole.

14. The battery cell according to claim 12 , wherein a projection of the first through hole is located within a projection of the second through hole in an axial direction of the first through hole.

15. The diameter of the first through hole is D 1 and the diameter of the second through hole is D 2 and D 1 and D 2 65%≦D 1 / D 2 The battery cell of claim 13 , wherein the cell satisfies ≦95%.

16. D 2 ≧D 1 The battery cell of claim 15 , wherein the offset is +0.2 mm.

17. The battery cell according to claim 1 , wherein a projection of the third through hole in the axial direction of the first through hole is smaller than a projection of the second through hole.

18. The battery cell according to claim 1 , wherein a projection of the third through hole in the axial direction of the first through hole is larger than a projection of the first through hole.

19. 2. The battery cell of claim 1, wherein, in an axial direction of the first through hole, a projection of the first through hole is located within a projection of the third through hole, and a projection of the third through hole is located within a projection of the second through hole.

20. The battery cell according to claim 1 , wherein the first through-hole, the second through-hole, and the third through-hole are arranged coaxially.

21. 2. The battery cell according to claim 1, wherein the electrode terminal includes a seal plate and a terminal body, the terminal body is provided with the first through hole, and the seal plate is connected to the terminal body and is used to seal the first through hole.

22. the terminal body includes a recess and a connection portion located on a side of the recess facing the electrode assembly, the first through-hole passes through the connection portion, and the connection portion realizes an electrical connection with the first tab by at least one first weld portion; 22. The battery cell of claim 21, wherein at least a portion of the seal plate is received in the recess.

23. 2. The battery cell according to claim 1, wherein the case includes a cylindrical body and a lid body connected to the cylindrical body, the cylindrical body is installed so as to surround an outer periphery of the electrode assembly, the lid body is provided with electrode lead-out holes, and the electrode terminals are installed in the electrode lead-out holes.

24. The battery cell according to claim 23 , wherein the lid and the cylindrical body are integrally molded.

25. 24. The battery cell of claim 23, wherein the electrode assembly further includes a second tab, the second tab having a polarity opposite to that of the first tab, and the second tab being electrically connected to the lid.

26. 26. The battery cell according to claim 25, wherein the first tab is located at an end of the electrode assembly facing the electrode terminal, and the second tab is located at an end of the electrode assembly facing away from the electrode terminal.

27. 26. The battery cell of claim 25, wherein the second tab is a negative tab and the base material of the case is steel.

28. 24. The battery cell of claim 23, wherein the cylindrical body has an opening at an end remote from the lid, and the battery cell further includes a cover plate for sealing the opening.

29. A battery comprising a plurality of battery cells according to any one of claims 1 to 28.

30. 30. A power consuming device comprising the battery of claim 29, said battery being adapted to provide electrical energy.

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