Battery cells, batteries, and power consumption devices

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 the priority of an application filed on August 23, 2021, with the invention title "Battery Cell, Its Manufacturing Method and Manufacturing System, Battery and Power Consumption Device" and the international application number PCT / CN2021 / 114156. All the contents of this application are incorporated herein by reference.

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

Background Art

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

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

Summary of the Invention

[0005] This application provides a battery cell, a battery, and a power consumption device, which can simplify the structure of the battery cell.

[0006] According to a first aspect, an embodiment of this application provides a battery cell, which includes an electrode assembly, a case, and an electrode terminal. The electrode assembly includes a first tab. The case is used to accommodate the electrode assembly. The electrode terminal is installed on the case and is electrically connected to the first tab. A first through - hole for injecting electrolyte into the internal space of the case is provided on the electrode terminal.

[0007] In the above proposed technology, by providing a first through-hole for injecting electrolyte into the electrode terminals, deformation of the case during the electrolyte 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 terminals are electrically connected to the first tab by at least one first weld.

[0009] In the above proposed technology, the first weld can reduce the resistance between the electrode terminal and the first tab, thereby improving overcurrent capability.

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

[0011] In the above proposed technology, the first welded portion increases the strength of the area located around the first through-hole of the electrode terminal, thereby reducing deformation of the electrode terminal due to the impact of the electrolyte.

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

[0013] In the above proposed technology, the outer circumference 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. As a result, some of the electrolyte flowing in through the first through-hole passes through this gap, thereby increasing the efficiency of electrolyte injection.

[0014] In some embodiments, the angle at which 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, and the higher the heat generated when current flows through the first weld. The above technical proposal limits α to 180° to 360°, thereby satisfying the battery cell's requirements for overcurrent capacity and temperature rise in the first weld.

[0016] In some embodiments, the first weld is multiple, and the multiple first welds are spaced apart along the circumferential direction of the first through hole.

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

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

[0019] The larger the value of angle β, the more sparsely the distribution of the multiple first welds is, and the smaller the total overcurrent area of ​​the multiple first welds. Conversely, the smaller the value of angle β, the more densely the distribution of the multiple first welds is, and the larger the total overcurrent area of ​​the multiple first welds. The embodiment of this application limits β to less than 30° to satisfy the requirements of the battery cell for overcurrent capacity and temperature rise, and reduces the risk of the first welds being torn apart when the battery cell vibrates.

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

[0021] In the above proposed technology, 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. The electrode terminal can increase its overcurrent capacity and reduce heat generation by arranging more first welds on the outer circumference 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. d and h satisfy the condition 0.1 ≤ h / d ≤ 0.6.

[0023] The larger h is, the greater the power required for welding, the higher the heat generated during the welding process, the greater the thermal stress acting on the region near the first through-hole, and the greater the degree of deformation of the first through-hole. The smaller d is, the greater the amount of heat conducted to the region near the first through-hole during the welding process, the greater the thermal stress acting on the region near the first through-hole, and the greater the degree of deformation of the first through-hole. If h / d is too large, the first through-hole will deform significantly, making it difficult to fit the fluid injection head into the first through-hole and affecting the fluid injection efficiency. The above technical proposal limits the value of h / d to 0.6 or less, thereby reducing the thermal stress acting on the region near the first through-hole, reducing the deformation of the first through-hole, and facilitating the fitting of the fluid injection head 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 during battery cell vibration. The larger d is, the smaller the area that can be used for welding the electrode terminals, and the more limited the overcurrent capacity and strength of the first weld. If h / d is too small, the overcurrent capacity and strength of the first weld are insufficient. The above proposed technology limits the value of h / d to 0.1 or greater, thereby meeting the requirements for the overcurrent capacity and strength of the first weld.

[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, the amount of heat generated conducted to the area near the first through hole in the welding process is too large, the thermal stress acting on the area near the first through hole is too large, the first through hole is greatly deformed, it is difficult for the liquid injection head to fit into the first through hole, and the liquid injection efficiency is affected. If d is too large, the area of the region that can be used for welding the electrode terminals is small, and the overcurrent capacity and strength of the first welding part are insufficient. The above technical solution limits the value of d to 1.6 mm to 5.5 mm, reduces the deformation of the first through hole, facilitates the fitting of the liquid injection head into the first through hole, and the overcurrent capacity and strength of the first welding part meet the requirements.

[0028] In some embodiments, the electrode assembly has a wound structure, and the electrode assembly has a second through hole at the winding center location. The first through hole communicates with the second through hole so that the electrolytic solution injected through the first through hole can flow into the second through hole.

[0029] In the above technical solution, in the liquid injection process, the electrolytic solution can flow into the second through hole through the first through hole, and the electrolytic solution flowing into the second through hole infiltrates the electrode assembly from the inside, which can improve the infiltration efficiency of the electrode assembly.

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

[0031] In the above technical solution, the first through hole and the second through hole are opposed along the axial direction of the first through hole, and some of the electrolytic solution passing through the first through hole can enter the second through hole without changing the flow, thereby improving the infiltration efficiency of the electrode assembly.

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

[0033] In the above proposed technology, the second through-hole has a relatively larger cross-sectional area compared to the first through-hole. Thus, the second through-hole can accommodate more electrolyte, contributing to an improved efficiency of electrolyte infiltration from the inside into the electrode assembly.

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

[0035] According to the above proposed technology, the entity portion of the electrode assembly can avoid the first through-hole, reducing the amount of electrolyte that directly impacts the electrode assembly and thus 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 more efficient the electrolyte injection becomes, the shorter the time it takes to fill with electrolyte, the less the amount of electrolyte that can penetrate the electrode assembly during the injection process, and the smaller the total amount of electrolyte injected. The smaller D2 is, the smaller the surface area of ​​the hole wall of the second through-hole, and the lower the efficiency of electrolyte penetration from inside the electrode assembly. If D1 / D2 is too large, the amount of electrolyte injected is small, affecting the cycle life of the battery cell. The above technical proposal limits the value of D1 / D2 to 95% or less, so that the amount of electrolyte injected meets the requirements.

[0038] The smaller D1 is, the lower the efficiency of electrolyte injection and the longer it takes for the electrolyte to fill. Conversely, the larger D2 is, the higher the efficiency of electrolyte infiltration from inside the electrode assembly. If D1 / D2 is too small, the injection time is long and the product production efficiency is low. Also, the larger D2 is, the smaller the capacity of the electrode assembly, the lower the space utilization rate inside the battery cell, and the lower the energy density of the battery cell. The above proposed technology increases the injection efficiency and reduces the loss of energy density in the battery cell due to the second through-hole by limiting the value of D1 / D2 to 65% or more.

[0039] In some implementations, D2 ≥ D1 + 0.2 mm.

[0040] When assembling battery cells, assembly errors can cause misalignment of the electrode assembly, resulting in the first through-hole facing the entity portion of the electrode assembly, thus leading to the electrode assembly being struck by the electrolyte. The above technical proposal sets D2 ≥ D1 + 0.2 mm to provide a margin of error for the electrode assembly, reducing the risk of the entity portion of the electrode assembly facing the first through-hole, reducing the amount of electrolyte directly striking the electrode assembly, and thus reducing the risk of deformation of the electrode assembly.

[0041] In some embodiments, the battery cell further includes a current collector for electrically connecting the electrode terminals to the first tab. The current collector includes a third through-hole, at least a portion of which is located between the first and second through-holes.

[0042] In the above proposed technology, by installing a third through-hole, the current collector component avoids the electrolyte flowing in through the first through-hole, reducing obstruction of the current collector component to the electrolyte during the electrolyte injection process. The electrolyte then smoothly passes through the third through-hole and flows into the second through-hole, improving the immersion 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 proposed technology, the second through-hole has a relatively larger cross-sectional area compared to the third through-hole. Thus, the electrolyte that has passed through the third through-hole flows rapidly into the second through-hole, contributing to an improved efficiency in the electrolyte's infiltration 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 proposed design, the third through-hole has a relatively larger cross-sectional area compared to the first through-hole, thus reducing the risk of the current collector component obstructing the first through-hole. The electrolyte can then smoothly pass through the third through-hole and enter the second through-hole, increasing the efficiency of the electrolyte infiltration into the electrode assembly from the inside.

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

[0048] The above technical proposal can reduce the risk of the current collector component blocking the first through-hole, allowing the electrolyte to flow smoothly into the case, as well as reducing the impact received by the current collector component and lowering the risk of the connection between the current collector component and the electrode terminal being torn.

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

[0050] The above technical proposal can reduce the shielding of the third through-hole in the entity portion of the electrode assembly, allowing the electrolyte to flow smoothly into the second through-hole.

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

[0052] In the above proposed technology, by coaxially arranging three through-holes, the inflow of electrolyte can be made smoother, and the impact of the electrolyte on the current collector components and electrode assembly can be reduced.

[0053] In some embodiments, the electrode terminal includes a sealing plate and a terminal body, the terminal body being provided with a first through-hole, and the sealing plate being connected to the terminal body and used to seal the first through-hole.

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

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

[0056] In the above proposed technology, by creating a recess in the terminal body, the thickness of the connection part can be reduced, thereby reducing the welding power required for welding, lowering the risk of other parts burning out, and improving safety. The recess also provides a accommodating space for the seal plate, 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 connected to the cylindrical body, the cylindrical body being positioned to surround the outer circumference of the electrode assembly, the lid being provided with electrode lead-out holes, and the electrode terminals being placed in the electrode lead-out holes.

[0058] In some embodiments, the lid and cylinder are integrally molded, eliminating the need for a separate connection step between the lid and cylinder. When the lid and cylinder are electrically connected to the positive or negative electrode of the electrode assembly, the integral structure of the connection point between the lid and cylinder results in relatively low resistance, thereby increasing overcurrent capability. The lid may also be used to connect to external components (e.g., busbar members), and if the battery cell is subjected to external impact, the external components may pull on the lid, potentially acting a force on the connection point between the lid and cylinder. The above-mentioned technology improves the strength of the connection point between the lid and cylinder by integrally mounting the lid and cylinder, reducing the risk of failure of the connection between the lid and cylinder.

[0059] In some embodiments, the electrode assembly further includes a second tab, the second tab having the opposite polarity to the first tab, and the second tab is electrically connected to the cover.

[0060] In the above proposed technology, one of the lid and electrode terminals may be the positive output terminal of the battery cell, and the other may be the negative output terminal of the battery cell. In this proposed technology, the positive output terminal and the negative output terminal are placed 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 the end of the electrode assembly facing the electrode terminals, and the second tab is located at the end of the electrode assembly away from the electrode terminals.

[0062] In the above proposed technology, by providing the first tab and the second tab at opposite ends of the electrode assembly, the pitch between the first tab and the second tab can be increased, reducing the risk of electrical contact between the first tab and the second tab and improving safety.

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

[0064] In the above proposed technology, the case is electrically connected to the negative electrode tab, meaning the case is in a low-potential state. A steel case is less susceptible to corrosion by the electrolyte in a low-potential state.

[0065] In some embodiments, the cylindrical body has an opening at the end away 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 which comprises a battery cell of any one embodiment of a plurality of first embodiments.

[0067] According to a third aspect, an embodiment of the present application provides a power consumption device which includes a battery of the second aspect for providing electrical energy. [Brief explanation of the drawing]

[0068] To more clearly illustrate the technical concept of the embodiments of this application, the following is a brief introduction to the drawings that may be used in the embodiments of this application. It is obvious that the drawings described below represent only a few embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without expending any creative effort. [Figure 1] This is a schematic diagram of the structure of a vehicle according to several embodiments of this application. [Figure 2] This is a schematic diagram of a battery exploded according to some embodiments of this application. [Figure 3] Figure 2 is a schematic diagram of the battery module's structure. [Figure 4] This is a schematic diagram of an exploded battery cell according to some embodiments of this application. [Figure 5] This is a schematic cross-sectional view of a battery cell according to several embodiments of this application. [Figure 6] Figure 5 is a schematic diagram showing a localized magnified view of the battery cell. [Figure 7] This is an enlarged schematic view of the corner frame B in Figure 6. [Figure 8] This is a schematic diagram of the electrode terminals of a battery cell according to some embodiments of this application. [Figure 9] This is an enlarged schematic diagram of the area within the circular frame C in Figure 7. [Figure 10] This is a schematic diagram of the terminal body of the electrode terminal of a battery cell according to some embodiments of this application. [Figure 11] This is a schematic diagram of the terminal body of the electrode terminal of a battery cell according to some other embodiments of this application. [Figure 12] This is a schematic diagram of the terminal body of the electrode terminal of a battery cell according to some other embodiments of this application. [Figure 13] This is a schematic local cross-sectional view of a battery cell according to some other embodiments of this application. [Figure 14] This is a schematic local cross-sectional view of a battery cell according to some other embodiments of this application. [Figure 15] This is a schematic cross-sectional view of a battery cell according to some other embodiments of this application.

[0069] In drawings, the drawings are not drawn to actual scale. [Modes for carrying out the invention]

[0070] To clarify the purpose, technical proposal, and advantages of the embodiments of this application, the following clearly describes the technical proposal in the embodiments of this application, linking it with the drawings of the embodiments. Clearly, the embodiments described are only some, not all, embodiments of this application. All other embodiments derived from the embodiments of this application without the creative effort of a person skilled in the art are all within the scope of protection of this application.

[0071] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as that commonly understood by those skilled in the art relating to this application. In this application, terms used in the specification are solely for the purpose of describing specific embodiments and are not intended to limit this application. The terms “includes” and “have,” and any variations thereof, in the description of the specification, claims, and drawings of this application are intended to intentionally cover the non-exclusive “includes.” Terms such as “first,” “second,” etc., in the specification, claims, or drawings of this application are not intended to describe a particular order or hierarchical relationship, but to distinguish different subjects.

[0072] The “Examples” as used in this application mean that certain features, structures, or characteristics described in conjunction with the Examples may be included in at least one Example of this application. The occurrence of this phrase in each location in the specification does not necessarily refer to the same Example, nor does it mean that each Example is mutually exclusive or alternative to the others.

[0073] In the description of this application, unless otherwise specifically defined or limited, the terms “attachment,” “connection,” “connection,” and “installation” should be understood in a broad sense. For example, a fixed connection may be a detachable connection, an integral connection, a direct connection, an indirect connection via an intermediate medium, or internal communication between two elements. A person skilled in the art will be able to understand the specific meaning of these terms in this application depending on the specific circumstances.

[0074] In this application, the terms "and / or" simply describe the relationship between related objects, indicating that three relationships are possible. For example, A and / or B can represent three cases: A alone, a combination of A and B, and B alone. In this application, the character " / " generally indicates that the preceding and succeeding related objects are in an "or" relationship.

[0075] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the dimensions such as thickness, length, and width of various components in the embodiments of this application shown in the drawings, and the overall dimensions such as thickness, length, and width of the integrating apparatus, are for illustrative purposes only and should not constitute any limitation to this application.

[0076] The term "multiple" as it appears in this application refers to two or more (including two).

[0077] In this application, the term "parallel" includes not only absolutely parallel cases but also cases that are approximately parallel in an engineering sense, and similarly, the term "perpendicular" includes not only absolutely perpendicular cases but also cases that are approximately perpendicular in an engineering sense.

[0078] In this application, the battery cell 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, or magnesium-ion battery cells, and the embodiments of this application are not limited thereto.

[0079] The batteries referred to in the embodiments of this application refer to a single physical module containing one or more battery cells to provide higher voltage and capacity. For example, the batteries referred to in this application may include a battery module or a battery pack. The batteries generally include a housing for packaging one or more battery cells. The housing can prevent liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0080] A battery cell comprises an electrode assembly and an electrolyte, the electrode assembly comprising 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 and negative electrode plates. The positive electrode plate comprises a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer being coated on the surface of the positive electrode current collector, the positive electrode current collector comprising a positive electrode current collector portion and a positive electrode tab, the positive electrode current collector portion being coated with the positive electrode active material layer, and the positive electrode tab not being coated with the positive electrode active material layer. Taking a lithium-ion battery as an example, the material of the positive electrode current collector may be aluminum, the positive electrode active material layer may contain a positive electrode active material, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode plate includes a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer being coated on the surface of the negative electrode current collector, the negative electrode current collector including a negative electrode current collecting portion and a negative electrode tab, the negative electrode current collecting portion being coated with the negative electrode active material layer and the negative electrode tab not being coated with the negative electrode active material layer. The material of the negative electrode current collector may be copper, the negative electrode active material layer may contain a negative electrode active material, the negative electrode active material may be carbon or silicon, etc. The material of the separator may be PP (polypropylene) or PE (polyethylene), etc.

[0081] The battery cell further includes a case for housing an electrode assembly and electrode terminals mounted on the case, the electrode terminals being electrically connected to the electrode assembly and used to enable charging and discharging of the electrode assembly.

[0082] During the battery production process, it is necessary to inject electrolyte into the case. To achieve this electrolyte injection, the inventor attempted to create an injection 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 the electrolyte into the case through the injection hole.

[0083] However, the inventors found that creating injection holes in the case complicates the case structure, the injection holes occupy space within the case, and affect the mounting of other components on the case. Compared to electrode terminals, the case is relatively thin and has relatively low strength, and during injection, the case may deform due to the extrusion of the injection head, thereby creating a risk of defects in the external shape of the battery cell.

[0084] In view of this, the embodiments of this application provide a technical solution that, by providing through holes for injecting electrolyte into the electrode terminals, reduces deformation of the case during the electrolyte injection process, simplifies the structure of the battery cell, and reduces the impact of the first through holes on the strength of the case.

[0085] The technical invention described in the embodiments of this application applies to batteries and power consumption devices that use batteries.

[0086] Power-consuming devices may include vehicles, mobile phones, portable devices, laptop computers, steamships, aerospace vehicles, electric toys, and power tools. Vehicles may be fuel-oil vehicles, gas vehicles, or new energy vehicles, and new energy vehicles may be pure electric vehicles, hybrid vehicles, or range-extender vehicles. Aerospace vehicles include airplanes, rockets, space shuttles, and spacecraft. Electric toys include stationary or mobile electric toys, such as game consoles, electric vehicle toys, electric steamship toys, and electric airplane toys. Power tools 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. The embodiments of this application do not particularly limit the power-consuming devices described above.

[0087] For the sake of explanation, the following embodiments will be described using a vehicle as the power consumption device.

[0088] Figure 1 is a schematic diagram of the structure of a vehicle according to some embodiments of this application. As shown in Figure 1, a battery 2 is installed inside the vehicle 1, and the battery 2 may be installed at the bottom, front, 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 the operating power source for the vehicle 1.

[0089] Vehicle 1 may further include a controller 3 and a motor 4, the controller 3 being used to control the battery 2 to supply power to the motor 4, for example, to meet the power consumption requirements for starting, navigating, and driving Vehicle 1.

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

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

[0092] The housing 5 is used to house battery cells, and the housing 5 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 overlap each other, and the first housing portion 5a, together with the second housing portion 5b, defines a housing space 5c for housing battery cells. The second housing portion 5b may be a hollow structure with one end open, the first housing portion 5a is a plate-like structure, the first housing portion 5a is placed over the open side of the second housing portion 5b to form a housing 5 having a housing space 5c, and both the first housing portion 5a and the second housing portion 5b may be hollow structures with one side open, the open side of the first housing portion 5a is placed over the open side of the second housing portion 5b to form a housing 5 having a housing space 5c. Of course, the first housing portion 5a and the second housing portion 5b may have various shapes, such as a cylinder or a rectangular parallelepiped.

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

[0094] If the first housing portion 5a is placed over the top of the second housing portion 5b, then the first housing portion 5a may be called the upper housing lid, and the second housing portion 5b may be called the lower housing.

[0095] In battery 2, there may be one battery cell or multiple battery cells. If there are multiple battery cells, they may be connected in series, in parallel, or in series-parallel. Series-parallel connection means that some of the battery cells are connected in series, and others are connected in parallel. Multiple battery cells may be directly connected in series, in parallel, or in series-parallel before the entire assembly composed of multiple battery cells is housed in the housing 5. Of course, multiple battery cells may first be connected in series, in parallel, or in series-parallel to form a battery module 6, and then the multiple battery modules 6 may be connected in series, in parallel, or in series-parallel to form a single whole, which is then housed in the housing 5.

[0096] Figure 3 is a schematic diagram of the battery module structure shown in Figure 2.

[0097] In some embodiments, as shown in Figure 3, there are multiple battery cells 7, which are first connected in series, in parallel, or in series-parallel to form a battery module 6. The multiple battery modules 6 are then connected in series, in parallel, or in series-parallel to form a single unit, which is housed in a casing.

[0098] Multiple battery cells 7 in the battery module 6 are electrically connected by busbar members 8, enabling parallel, series, or series-parallel connection of the multiple battery cells 7 in the battery module 6. There may be one or more busbar members, and each busbar member 8 is used to electrically connect at least two battery cells.

[0099] Figure 4 is an exploded schematic diagram of a battery cell according to some embodiments of this application, Figure 5 is a cross-sectional schematic diagram of a battery cell according to some embodiments of this application, Figure 6 is a localized magnified schematic diagram of the battery cell shown in Figure 5, and Figure 7 is a magnified schematic diagram of the corner frame B in Figure 6.

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

[0101] The electrode assembly 10 includes a first plate and a second plate, which have opposite polarities. One of the first and second plates is the positive electrode plate, and the other is the negative electrode plate. Exemplarily, the electrode assembly 10 generates electrical energy through oxidation and reduction reactions during the intercalation / deintercalation of ions at the positive and negative electrode plates. Optionally, the electrode assembly 10 further includes a separator for insulating the first and second electrode plates.

[0102] In some examples, the first electrode plate, the second electrode plate, and the separator are all strip-shaped structures, 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 cylindrical, flattened, or of other shapes. In some other examples, the electrode assembly 10 may be a laminated 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 covered by the 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 its interior forms a space for housing the electrode assembly 10. The case 20 may have various shapes and sizes, such as a rectangular parallelepiped, cylindrical shape, or 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 can be selected, and if the electrode assembly 10 has a rectangular parallelepiped structure, a rectangular parallelepiped case can be selected. Selectively, both the electrode assembly 10 and the case 20 are cylindrical.

[0105] The material of case 20 can vary and may be, for example, copper, iron, aluminum, stainless steel, aluminum alloy, etc., and the embodiments of this application are not particularly limited thereto.

[0106] In case 20, the object may be positively charged, negatively charged, or not charged at all.

[0107] The electrode terminals 30 may be insulated from the case 20, or they may be electrically connected to the case 20. The embodiments of this application do not limit this, as long as electrical conductivity 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 achieve an electrical connection between the electrode terminal 30 and the first tab 11. Exemplarily, the electrode terminal 30 may be connected to the first tab 11 by bonding, abutting, locking, welding or other means.

[0109] Alternatively, the electrode terminal 30 can be indirectly connected to the first tab 11 by other conductive components to achieve an electrical connection between the electrode terminal 30 and the first tab 11. For example, a conductive component may be connected to both the first tab 11 and the electrode terminal 30 simultaneously to achieve an electrical connection between the electrode terminal 30 and the first tab 11.

[0110] The electrode terminals 30 may also serve as output electrodes for the battery cell 7, thereby electrically connecting the battery cell 7 to an external circuit and enabling charging and discharging of the battery cell 7. Selectively, the electrode terminals 30 are connected to a busbar member and used to achieve electrical connection between the battery cells 7.

[0111] The first through-hole 323 may be one or multiple.

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

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

[0114] In some embodiments, the first through-hole 323 may be used in other processes, such as chemical conversion processes.

[0115] In 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 vent the gas from 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, the first tab 11 and the second tab 13 protruding from the main body 12. The first tab 11 is the portion of the first electrode plate whose active material layer is not coated, and the second tab 13 is the portion of the second electrode plate whose active material layer is not coated.

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

[0118] In some embodiments, the first tab 11 is wound in multiple turns around the central axis A of the electrode assembly 10, in other words, the first tab 11 comprises multiple layers of tabs. After winding is complete, the first tab 11 is substantially columnar, with gaps remaining between adjacent pairs of tab layers. Embodiments of the present application can process the first tab 11 to reduce the gaps between the tab layers and facilitate connection between the first tab 11 and other members. For example, embodiments of the present application can process the first tab 11 so that the end region away from the body 12 of the first tab 11 is narrowed and converged, and the process of processing the first tab 11 to reduce the gaps between the tab layers and facilitate connection between the first tab 11 and other members. Alternatively, embodiments of the present application can also process the gaps between the tab layers by filling the space between adjacent pairs of tab layers with conductive material.

[0119] In some embodiments, the second tab 13 is wound in multiple turns around the central axis A of the electrode assembly 10, and the second tab 13 includes multiple layers of tabs. Exemplarily, the second tab 13 is also subjected to a kneading and planarizing treatment to reduce the gaps between the tab layers of the second tab 13.

[0120] The central axis A of the electrode assembly 10 is a hypothetical straight line. The first electrode plate, the second electrode plate, and the separator may be wound with respect to the central axis A.

[0121] In some embodiments, the case 20 includes a cylindrical body 21 and a lid 22 connected to the cylindrical body 21, the cylindrical body 21 being positioned to surround the outer circumference of the electrode assembly 10, the lid 22 being provided with electrode lead-out holes 221, and the electrode terminals 30 being positioned in the electrode lead-out holes 221.

[0122] The lid 22 and the cylindrical body 21 may be formed as a single unit; that is, the case 20 is a single molded part. Of course, the lid 22 and the cylindrical body 21 may be two separate parts that are connected by welding, riveting, bonding, or other methods.

[0123] The electrode extraction hole 221 penetrates the lid 22 to facilitate the extraction of electrical energy from the electrode assembly 10 to the outside of the case 20.

[0124] The central axis A is a hypothetical 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 some 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 used to cover the electrode lead-out hole 221. The electrode terminal 30 may or may not enter the electrode lead-out hole 221. The electrode terminal 30 is fixed to the cover 22. The electrode terminal 30 may be fixed entirely to the outside of the cover 22, or it may enter the inside of the case 20 through the electrode lead-out hole 221.

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

[0127] In some embodiments, the lid 22 and the cylindrical body 21 are integrally molded. This eliminates the need for a connecting step between the lid 22 and the cylindrical body 21.

[0128] When the cover 22 and the cylinder 21 are electrically connected to the positive or negative electrode of the electrode assembly 10, the connection point between the cover 22 and the cylinder 21 is a single integrated structure, resulting in relatively low resistance at the connection point between the cover 22 and the cylinder 21, thereby increasing the overcurrent capability. The cover 22 may also be used to connect to external components (e.g., busbar members), and if the battery cell is subjected to external impact, the external components may pull on the cover 22, potentially acting a force on the connection point between the cover 22 and the cylinder 21. The above-mentioned technology improves the strength of the connection point between the cover 22 and the cylinder 21 by integrally mounting the cover 22 and the cylinder 21, thereby reducing the risk of failure of the connection between the cover 22 and the cylinder 21.

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

[0130] In some embodiments, the cylindrical body 21 has an opening 211 at the end away from the lid 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 may have 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 shape.

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

[0134] In some embodiments, the lid 22 is circular, the electrode assembly 10 is cylindrical, and the central axis A and the axis of the electrode extraction hole 221 are aligned. This embodiment does not require that the central axis A and the axis of the electrode extraction hole 221 be perfectly aligned, and there may be process-acceptable variation between the two.

[0135] In this embodiment, the electrode extraction hole 221 is located approximately in the middle of the cover 22, and accordingly, the electrode terminals 30 are also attached to the middle of the cover 22. When assembling multiple battery cells 7 into a set, the requirements for positioning accuracy of the electrode terminals 30 can be reduced, and the assembly process can be simplified.

[0136] For example, the axis of the electrode extraction hole 221 and the axis of the cover 22 are aligned, and the cover 22 is an annular structure installed around the axis of the electrode extraction hole 221.

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

[0138] In some other embodiments, the cover 22 may be rectangular and the electrode assembly 10 may be flattened. The electrode extraction holes 221 may be positioned closer to the ends of the cover 22 along its own longitudinal direction.

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

[0140] In some embodiments, the electrode assembly 10 further includes a second tab 13, the second tab 13 having the opposite polarity to the first tab 11, and the second tab 13 being electrically connected to the cover 22.

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

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

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

[0144] The cover 22 and the electrode terminals 30 have different polarities. In this case, one of the cover 22 and electrode terminals 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 placed on the same side of the battery cell 7, thus simplifying the connection process between multiple battery cells 7.

[0145] The cover 22 may be used to electrically connect to the busbar member. The inventors previously attempted to create a first through-hole in the cover, but the first through-hole reduces the connection area between the cover and the busbar member, reducing the overcurrent area between the cover and the busbar member, making it difficult to meet the battery cell's requirements for overcurrent capacity and temperature rise during rapid charging. Therefore, the inventors created a first through-hole 323 for fluid injection at the electrode terminal 30 to increase the connection area between the cover 22 and the busbar member.

[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 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 electrical contact between the first tab 11 and the second tab 13 and improving safety.

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

[0149] Case 20 is electrically connected to the negative electrode tab, meaning that case 20 is in a low potential state. The steel case 20 is less susceptible to corrosion by the electrolyte in a low potential state.

[0150] The electrode extraction holes 221 in the embodiment of this application are made after the stretch molding of the case 20.

[0151] The inventor previously attempted to form a burring structure by rolling the open end of a cylindrical body and folding it inward. This burring structure would then press against the cover plate to secure it. The inventor attached electrode terminals to the cover plate, making the burring structure and electrode terminals the two output electrodes of the battery cell. However, the larger the size of the burring structure, the higher the risk of curling and wrinkling after molding. If curling and wrinkling occur in the burring structure, irregularities will form on its surface, leading to welding defects if the burring structure is welded to an external busbar member. Therefore, the size of the burring structure is relatively limited, which can result in insufficient overcurrent capacity for the battery cell.

[0152] In this embodiment, electrode lead-out holes 221 for attaching electrode terminals 30 are formed in the lid 22 using the hole-opening process, and the positive and negative output electrodes are placed at the ends away from the opening of the cylindrical body 21 of the battery cell 7. The lid 22 is formed during the molding process of the case 20, and flatness can be ensured even after the electrode lead-out holes 221 are opened, ensuring the connection strength between the lid 22 and the busbar member. At the same time, since the flatness of the lid 22 is not constrained by its own size, the lid 22 can have a relatively large size, thereby improving the overcurrent capacity of the battery cell 7.

[0153] In some embodiments, the electrode terminal 30 is electrically connected to 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 welded portion W1. Current is conducted between the electrode terminal 30 and the first tab 11 through the first welded portion W1.

[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 may melt to form a molten pool, and after the molten pool solidifies, the first weld W1 may be formed.

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

[0157] The embodiments of this application do 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, square, ring-shaped, spiral, V-shaped, or other shapes. There may be one first weld W1 or multiple welds.

[0158] The first weld W1 can reduce the resistance between the electrode terminal 30 and the first tab 11, thereby improving overcurrent capability.

[0159] Figure 8 is a schematic diagram of the electrode terminals of a battery cell according to some embodiments of this application, Figure 9 is an enlarged schematic diagram of the circular frame C in Figure 7, and Figure 10 is a schematic diagram of the terminal body of the electrode terminals of a battery cell according to some embodiments of this application.

[0160] Referring together 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 being provided with a first through hole 323, and the seal plate 33 being connected to the terminal body 34 and 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 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, the connecting portion 32 making an electrical connection with the first tab 11 by at least one first weld W1. At least a portion of the seal plate 33 is housed in the recess 31.

[0163] The recess 31 can be recessed along the direction from the side of the terminal body 34 away from the electrode assembly 10 toward the electrode assembly 10. The connecting portion 32 is the portion of the terminal body 34 that corresponds to the bottom surface of the recess 31.

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

[0165] The connecting portion 32 is welded to another member to form a first weld W1. Exemplarily, the welding equipment can irradiate the surface of the connecting portion 32 toward the recess 31 with a laser, and the laser can melt a portion of the connecting portion 32 and a portion of the member located inside the connecting portion 32, forming a molten pool, and after the molten pool solidifies, the first weld W1 can be formed.

[0166] In the embodiments of this application, by providing a recess 31 in the terminal body 34, the thickness of the connection portion 32 can be reduced, thereby reducing the welding power required for welding, lowering the risk of other parts being burned, and improving safety. The recess 31 provides a accommodating space for the seal plate 33, thereby reducing the protrusion size of the seal plate 33 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, lowers 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 connecting portion 32 is 0.5 mm to 10 mm.

[0169] In some embodiments, a gap is provided between the seal plate 33 and the connecting portion 32 to avoid the first weld portion 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 the assembly process, affecting the sealing effect. In this embodiment, by creating a gap between the seal plate 33 and the connecting part 32, the seal plate 33 avoids the first weld W1, preventing direct contact between the seal plate 33 and the first weld W1, thereby reducing rattle of the seal plate 33 during the assembly process and ensuring a sealing effect.

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

[0172] The recess 31 is a stepped recess, with a larger outer surface and a smaller inner surface.

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

[0174] In some embodiments, the sealing plate 33 is welded to the side wall 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 groove 324 that is recessed in a direction toward the electrode assembly 10 from the first outer surface 322 of the connecting portion 32.

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

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

[0178] In this embodiment, a stepped structure is formed in the connecting portion 32 by creating a groove 324 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, it is necessary to fit external equipment into the connection part 32. The surface of the first weld W1 is uneven, and when the external equipment is pressed against the first weld W1, the external equipment is susceptible to being crushed by the first weld W1. In this embodiment, by providing a groove 324, a gap is formed 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 equipment so as to separate the external equipment from the first weld W1 and reduce the risk of the external equipment being crushed.

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

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

[0182] In some embodiments, the terminal body 34 has a second outer surface 344 and a second inner surface 345 that are positioned opposite each other. The second inner surface 345 faces the electrode assembly 10, while the second outer surface 344 is 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 connector 32.

[0183] In some embodiments, the seal plate 33 may be used to weld to the busbar member of the battery. In the battery, the busbar member may connect the seal plate 33 of one battery cell 7 to the cover 22 of another battery cell 7, thereby connecting the two battery cells 7 in series.

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

[0185] If 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 that is separated 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 avoiding interference between the seal plate 33 and the busbar member by the second outer surface 344 and ensuring that the busbar member is in close contact with the seal plate 33.

[0187] In some embodiments, the connector 32 is the end of the terminal body 34 facing the electrode assembly 10. 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 constitutes a part of the second inner surface 345. In this way, the terminal body 34 can be fitted to a current collector having a flat plate structure. In this embodiment, bonding of the connecting portion 32 and the current collector can be achieved simply by bonding the current collector to the second inner surface 345, and welding of the connecting portion 32 and the current collector 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, wherein at least a portion of the columnar portion 341 is located within the electrode lead-out 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, the first stopper portion 342 and the second stopper portion 343 are provided on the outside and inside of the cover 22, respectively, and are used to clamp a portion of the cover 22.

[0190] The provision of the first stopper portion 342 on the outside of the lid 22 means that the first stopper portion 342 is provided on the side of the lid 22 that is away from the electrode assembly 10, and the provision of the second stopper portion 343 on the inside of the lid 22 means that the second stopper portion 343 is provided on the side of the lid 22 that is facing the electrode assembly 10.

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

[0192] The first stopper portion 342 and the second stopper portion 343 clamp a part of the cover 22 from both sides, fixing the terminal body 34 to the cover 22. The first stopper portion 342 and the second stopper portion 343 may directly clamp the cover 22, or they may indirectly clamp the cover 22 with other parts.

[0193] Selectively, the columnar portion 341 is cylindrical. The first stopper portion 342 and the second stopper portion 343 are both annular structures surrounding the columnar portion 341.

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

[0195] The first insulating component 60 and the second insulating component 70 are both ring-shaped structures installed so as to surround the columnar portion 341.

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

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

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

[0199] In some embodiments, one of the first insulating component 60 and the second insulating component 70 is used to seal the electrode lead hole 221. In some examples, the first stopper portion 342 and the cover 22 push out the first insulating component 60, which is compressed and seals the electrode lead hole 221 from the outside. In some other examples, the second stopper portion 343 and the cover 22 push out the second insulating component 70, which is compressed and seals the electrode lead 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 used to seal the electrode lead hole 221. Selectively, a portion of the seal ring 80 extends into the electrode lead hole 221, separating the hole wall of the electrode lead hole 221 from the columnar portion 341.

[0201] In some embodiments, a plurality of protruding structures 342a are provided on the outer circumference of the first stopper portion 342, and the plurality of protruding structures 342a are installed at intervals along the circumferential direction of the columnar portion 341.

[0202] Selectively, the multiple protruding structures 342a may be installed at intervals along the circumferential direction of the columnar portion 341 or the like.

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

[0204] Before assembling the terminal body 34 into the case 20, the first stopper portion 342 of the terminal body 34 is substantially cylindrical and located at the upper end of the columnar portion 341, with the outer wall of the first stopper portion 342 being flush with the outer wall of the columnar portion 341. When assembling the terminal body 34 and the case 20, after the first stopper portion 342 passes through the electrode lead-out hole 221, the first stopper portion 342 is pushed out, causing the first stopper portion 342 to fold outward and crimp the terminal body 34 to the cover 22.

[0205] Before folding back the first stopper portion 342, a plurality of spaced groove structures 342b are provided at the upper end of the first stopper portion 342. After folding back the first stopper portion 342, a plurality of spaced projection structures 342a are formed along the circumferential direction of the columnar portion 341, with spaced groove structures 342b between adjacent projection structures 342a. This embodiment reduces the difficulty of folding back the first stopper portion 342 and minimizes stress concentration on the first stopper portion 342 by providing the groove structures 342b and projection structures 342a.

[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, causing the end of the terminal body 34 facing the electrode assembly 10 to extend outward due to the action of pressure, forming a protruding second stopper portion 343.

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

[0208] The current collector component 40 electrically connects the first tab 11 to the electrode terminal 30. The embodiments of this application do not limit the method of connection between the first tab 11 and the current collector component 40, and for example, the current collector component 40 may be connected to the first tab 11 by welding, abutment, or adhesive.

[0209] The current collector component 40 is welded to the electrode terminal 30, forming at least one first welded portion W1.

[0210] For example, the current collector component 40 is welded to the connector 32 to form at least one first weld W1. When welding the connector 32 and the current collector component 40, the first through-hole 323 plays a role in releasing welding stress, thereby reducing the risk of the connector 32 rupturing.

[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 away from the current collector 40 to at least the interior of the current collector 40.

[0212] During welding, for example, after the electrode assembly 10 and the current collector component 40 are mounted inside the case 20 and the current collector component 40 is pressed against the connector 32, an external welding device can weld the connector 32 and the current collector component 40 from the side of the connector 32 away from the current collector component 40 to form a first weld W1. The first weld W1 is exposed on the surface of the connector 32 away from the current collector component 40.

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

[0214] The first welded joint W1 extends from the connection part 32 into the interior of the current collector component 40, connecting the current collector component 40 and the connection part 32, reducing the contact resistance between the current collector component 40 and the electrode terminal 30, and improving the overcurrent capability.

[0215] In some embodiments, the first weld W1 does not protrude beyond the surface of the current collector component 40 that is separated from the connection portion 32 in the thickness direction of the connection portion 32.

[0216] A predetermined distance is maintained between the first welded joint W1 and the surface separating from the connection portion 32 of the current collector component 40 to prevent the current collector component 40 from melting off, reduce the risk of metal particles being generated on the surface separating from the connection portion 32 of the current collector component 40, and improve safety.

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

[0218] When assembling the battery cell 7, first the first tab 11 of the electrode assembly 10 is welded to the current collector 40, and then the electrode assembly 10 and the current collector 40 can be placed inside the case 20. Specifically, when welding the first tab 11 to the current collector 40, first the current collector 40 is pressed against the flattened end face of the first tab 11, and then an external welding device emits a laser onto the surface of the current collector 40 that is separated from the first tab 11, and the current collector 40 and the first tab 11 can be welded together by the laser.

[0219] The shape of the second weld W2 is straight, C-shaped, ring-shaped, spiral, V-shaped, or other shape. This embodiment is not limited to this, and the second weld W2 may be one or multiple.

[0220] The second weld W2 can reduce the contact resistance between the current collector 40 and the first tab 11, thereby improving the overcurrent capability.

[0221] In some embodiments, the current collector component 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 collector component 40 and the electrode assembly 10, first, the protrusion 41 of the current collector component 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 more firmly bonded to the first tab 11, and the risk of welding defects can be reduced.

[0223] In some embodiments, the protrusion 41 can extrude the first tab 11 and be incorporated into the first tab 11.

[0224] In some embodiments, other than the protrusion 41, the other parts of the current collector component 40 are substantially flat.

[0225] In some embodiments, a recessed structure 44 is formed at a position corresponding to a protrusion 41 of the current collector component 40, and the recessed structure 44 is recessed along the direction toward the first tab 11 relative to the surface of the current collector component 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 weld portion W2. By installing the recessed structure 44, the thickness of the adapter portion can be reduced, thereby reducing the welding power required to weld the adapter portion to the first tab 11, reducing heat generation, and lowering the risk of burnout of the electrode assembly 10.

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

[0227] In some embodiments, the number of 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 be an annular or semi-annular structure. The size of the first weld W1 extending along the circumferential direction Y may be determined according to the requirements of the battery cell 7 for overcurrent capacity, and this embodiment does not particularly limit this.

[0229] The first welded joint W1 increases the strength of the area located around the first through-hole 323 of the electrode terminal 30, thereby reducing deformation of the electrode terminal 30 due to the impact of 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 circumference 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., current collector component 40) is not blocked by the first weld W1. As a result, some of the electrolyte flowing in through the first through-hole 323 passes through this gap, thereby increasing the efficiency of electrolyte injection.

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

[0234] Selectively, 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 is, the smaller the overcurrent area of ​​the first weld W1, and the higher the heat generated when current flows through the first weld W1. In the embodiment of this application, by satisfying α to be 180° ≤ α ≤ 360°, the first weld W1 satisfies the requirements of the battery cell 7 for overcurrent capacity and temperature rise.

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

[0237] As shown in Figure 11, in some embodiments, the first weld W1 surrounds the first through hole 323, i.e., α is 360°.

[0238] The embodiment of this 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, thereby 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] Figure 12 is a schematic diagram of the terminal body of the electrode terminal of a battery cell according to some other embodiments of this application.

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

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

[0242] In this embodiment, the spacing angle in the circumferential direction Y of the first through holes 323 of two adjacent first welds W1 is not particularly limited. The multiple first welds W1 may be arranged at equal intervals along the circumferential direction Y of the first through holes 323, or they may be installed at unequal intervals.

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

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

[0245] The larger the value of angle β, the more sparsely the distribution of the multiple first welds W1, and the smaller the total overcurrent area of ​​the multiple first welds W1. Conversely, the smaller the value of angle β, the more densely the distribution of the multiple first welds W1, and the larger the total overcurrent area of ​​the multiple first welds W1. The embodiment of this application limits β to less than 30° to satisfy the requirements of the battery cell 7 for overcurrent capacity and temperature rise, and reduces the risk of the first welds W1 being torn apart 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 along the radial direction 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 along 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 on the outer circumference 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. d and h satisfy the condition 0.1 ≤ h / d ≤ 0.6.

[0250] Due to process errors, different areas of the first weld W1 may have different penetrations in the axial X direction of the first through-hole 323. h may be the size along the axial X direction of the first through-hole 323 in the area of ​​the first weld W1 with the least penetration.

[0251] The larger h is, the greater the power required for welding, the higher the heat generated during the welding process, the greater the thermal stress acting on the region near 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 region near the first through-hole 323 during the welding process, the greater the thermal stress acting on the region near 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 deforms significantly, making it difficult to fit the fluid injection head into the first through-hole 323 and affecting the fluid injection efficiency. As a result of diligent research and numerous experiments, the inventors have found that by limiting the value of h / d to 0.6 or less, the thermal stress acting on the region near the first through-hole 323 is reduced, the deformation of the first through-hole 323 is reduced, and it becomes easier to fit the fluid injection head 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 being torn when the battery cell 7 vibrates. The larger d is, the smaller the area that can be used for welding the electrode terminal 30, and the more limited 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 are insufficient. As a result of diligent research and numerous experiments, the inventors found that by limiting the value of h / d to 0.1 or greater, the overcurrent capacity and strength of the first weld W1 meet the requirements.

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

[0254] In some embodiments, d and h satisfy 0.2 ≤ h / d ≤ 0.5. As a result of diligent research and numerous experiments, the inventors 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 region near the first through-hole 323 during the welding process, the thermal stress acting on the region near the first through-hole 323 is too large, the first through-hole 323 deforms significantly, the fluid injection head is difficult to fit into the first through-hole 323, and the fluid injection efficiency is affected. If d is too large, the area of ​​the electrode terminal 30 that can be used for welding is small, and the overcurrent capacity and strength of the first weld W1 are insufficient.

[0257] As a result of diligent research and numerous experiments, the inventors found that by limiting the value of d to 1.6 mm to 5.5 mm, the deformation of the first through-hole 323 is reduced, the fitting of the liquid injection head into the first through-hole 323 is facilitated, and the overcurrent capacity and strength of the first weld W1 can meet the requirements.

[0258] Selectively, 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 wound. The first through-hole 323 communicates with the second through-hole 14 so that the electrolyte injected through the first through-hole 323 flows into the second through-hole 14.

[0261] Exemplary, the electrode assembly 10 is made by winding a first electrode plate, a second electrode plate, and a separator onto a winding tool, and after winding, the winding tool is withdrawn from the electrode assembly 10. After the winding tool is withdrawn, a second through hole 14 is formed in the middle 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] The embodiments of this application do not particularly limit the size relationship between the diameter of the first through hole 323 and the diameter of the second through hole 14.

[0264] In the electrolyte 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 permeate the electrode assembly 10 from the inside, improving the permeation 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, in the axial direction X of the first through-hole 323, the projection of the first through-hole 323 at least partially overlaps with the projection of the second through-hole 14.

[0267] The first through-hole 323 and the second through-hole 14 are positioned opposite each other along the axial direction X of the first through-hole 323, and some of the electrolyte passing through the first through-hole 323 enters the second through-hole 14 without changing its flow, thereby improving the immersion efficiency of the electrode assembly 10.

[0268] Selectively, if the first through-hole 323 is a diameter-changing hole, the projection of the first through-hole 323 along its own axial X is the projection of the opening at the inner end of the first through-hole 323 along its own axial X. If the second through-hole 14 is a diameter-changing hole, the projection of the second through-hole 14 along the axial X of the first through-hole 323 is the projection of the opening at the end of the second through-hole 14 closest to the first through-hole 323 along the axial 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 projection of the first through-hole 323 along its own axial direction X is S1, and the area of ​​the projection of the second through-hole 14 along the axial direction X of the first through-hole 323 is S2, where S2 is greater than S1.

[0271] Compared to 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, contributing to an improved efficiency of electrolyte infiltration from the inside into the electrode assembly 10.

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

[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. Exemplarily, the embodiment of this application can reduce the impact received by the first tab 11 and separator and reduce deformation of the first tab 11 and separator.

[0274] In some embodiments, the diameter of the first through hole 323 is D1, and the diameter of the second through hole 14 is D2, such that D1 and D2 satisfy 65% ​​≤ D1 / D2 ≤ 95%.

[0275] For example, 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 more efficient the electrolyte injection becomes, the shorter the time it takes to fill with electrolyte, the less the amount of electrolyte that can penetrate the electrode assembly 10 during the injection process, and the smaller the total amount of electrolyte injected. The smaller D2 is, the smaller the surface area of ​​the hole wall of the second through hole 14, and the lower the efficiency of electrolyte penetration from inside the electrode assembly 10. If D1 / D2 is too large, the amount of electrolyte injected is small, affecting the cycle life of the battery cell 7. As a result of diligent research and numerous experiments, the inventors found that by limiting the value of D1 / D2 to 95% or less, the amount of electrolyte injected meets the requirements.

[0277] The smaller D1 is, the lower the efficiency of electrolyte injection and the longer it takes for the electrolyte to fill. Conversely, the larger D2 is, the higher the efficiency of electrolyte infiltration from inside the electrode assembly 10. If D1 / D2 is too small, the injection time is long and the product production efficiency is low. Also, the larger D2 is, the smaller the capacity of the electrode assembly 10, the lower the space utilization rate inside the battery cell 7, and the lower the energy density of the battery cell 7. As a result of diligent research and numerous experiments, the inventors found that limiting the value of D1 / D2 to 65% or more improves the injection efficiency and reduces the loss of energy density in the battery cell 7 due to the second through-hole 14.

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

[0279] In some implementations, D2 ≥ D1 + 0.2 mm.

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

[0281] As a result of intensive research and a large number of experiments, the inventor has found that by setting D2≧D1 + 0.2 mm, a margin for displacement is provided for the electrode assembly 10, reducing the risk that the entity part of the electrode assembly 10 faces the first through-hole 323, reducing the electrolyte directly impacting the electrode assembly 10, and reducing the risk that the electrode assembly 10 is deformed.

[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 are overlapped. Exemplarily, 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 component 40 for electrically connecting the electrode terminal 30 and the first tab 11. The current collecting component 40 includes a third through-hole 45, and at least a part of the third through-hole 45 is provided between the first through-hole 323 and the second through-hole 14.

[0284] In this embodiment, the aperture diameter of the third through-hole 45 is not particularly limited, and the aperture diameter may be larger than, smaller than, 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, that is, the projection of the third through-hole 45 along the axial direction X of the first through-hole 323 at least partially overlaps with the 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, that is, the projection of the third through-hole 45 along the axial direction X of the first through-hole 323 at least partially overlaps with the projection of the second through-hole 14 along the axial direction X of the first through-hole 323.

[0286] By installing the third through-hole 45, the current collecting component 40 avoids the electrolyte flowing in through the first through-hole 323, reduces the blockage of the current collecting component 40 against the electrolyte in the liquid injection process, and the electrolyte can smoothly flow into the second through-hole 14 through the third through-hole 45, 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 aperture diameter of the third through-hole 45 is greater than or equal to the aperture diameter of the first through-hole 323. The aperture diameter of the third through-hole 45 is less than or equal to the aperture diameter of the second through-hole 14.

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

[0290] The area of the projection of the third through-hole 45 along the axial direction X of the first through-hole 323 is S3, and S2 is greater than S3. Exemplarily, the aperture diameter of the third through-hole 45 is smaller than the aperture 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. Thus, the electrolyte passing through the third through-hole 45 can quickly flow into the second through-hole 14, contributing to the improvement of the efficiency of the electrolyte infiltrating the electrode assembly 10 from the inside.

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

[0293] Compared to the first through-hole 323, the third through-hole 45 has a relatively larger cross-sectional area, thus reducing the risk of the current collector component 40 obstructing the first through-hole 323. This allows the electrolyte to enter the second through-hole 14 smoothly through the third through-hole 45, increasing the efficiency of electrolyte infiltration into the electrode assembly 10 from the inside.

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

[0295] This embodiment can reduce the risk of the current collector component 40 obstructing the first through-hole 323, allowing the electrolyte to flow smoothly into the case 20, as well as reducing the impact on the current collector component 40 and lowering the risk of the connection between the current collector component 40 and the electrode terminal 30 tearing.

[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 X direction 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 flow smoothly 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 coaxially positioned. Coaxial positioning means that the central axes of the first through-hole 323, the second through-hole 14, and the third through-hole 45 are aligned. Of course, the alignment in these embodiments does not require absolute alignment, and an engineeringly reasonable error is permitted.

[0298] By coaxially arranging the three through-holes, the electrolyte inflow is smoother, and the impact of the electrolyte on the current collector component 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 collector 40 protrudes radially inward from the wall of the second through-hole 14. The current collector 40 shields the first tab 11, reducing the impact on the first tab 11 from the electrolyte.

[0300] Figure 13 is a schematic local cross-sectional view of a battery cell according to some other embodiments of this application.

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

[0302] Compared to the battery cell shown in Figure 6, the battery cell 7 shown in Figure 13 simplifies the internal structure of the battery cell 7 by omitting the current collection component, shortens the conductive path between the electrode terminal 30 and the first tab 11, and increases the energy density of the battery cell 7.

[0303] According to some embodiments of this application, a battery is further provided, which comprises a battery cell of any one of the multiple embodiments.

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

[0305] As shown in Figure 14, in some embodiments, the recess of the electrode terminal 30 can be omitted. For example, the first through-hole 323 may pass through the terminal body 34, and the terminal body 34 may not have the recess 31 shown in Figure 6. The sealing plate 33 may be placed directly over the terminal body 34 to seal the first through-hole 323.

[0306] Figure 15 is a schematic cross-sectional view of a battery cell according to some other embodiments of this application.

[0307] As shown in Figure 15, in some embodiments, the battery cell 7 may be a rectangular battery cell.

[0308] In some embodiments, the case 20 includes a cylindrical body 21 and a lid 22 formed integrally, and the cylindrical body 21 is installed to surround the outer periphery of the electrode assembly 10. Exemplarily, the cylindrical body 21 may be a rectangular cylinder.

[0309] At an end of the cylindrical body 21 that is separated from the lid 22, there is an opening, and the cover plate 50 is placed over the opening of the cylindrical body 21 to seal the opening of the cylindrical body 21. Exemplarily, 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 with opposite polarities. The first electrode terminal 30 is used to be electrically connected to the first tab of the electrode assembly 10, and the second electrode terminal 90 is used to be electrically connected to the second tab of the electrode assembly 10.

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

[0312] In a battery, the bus bar member is connected to the electrode terminals of a plurality of battery cells to connect the plurality of battery cells in series, in parallel, or in series-parallel. Both the first electrode terminal 30 and the second electrode terminal 90 may be used to be connected to the bus bar member.

[0313] When the battery is subjected to an external impact, the bus bar member pulls the lid 22 by the first electrode terminal 30 and the second electrode terminal 90, and a force acts on the connection portion between the lid 22 and the cylindrical body 21. When the lid 22 and the cylindrical body 21 are of a separate structure, for example, when the lid 22 and the cylindrical body 21 are connected by welding, the connection portion between the lid 22 and the cylindrical body 21 may fail due to the action of the force. The embodiments of the present application improve the strength of the connection portion between the lid 22 and the cylindrical body 21 by installing the lid 22 and the cylindrical body 21 integrally, and reduce the risk of the connection between the lid 22 and the cylindrical body 21 failing.

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

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

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

[0317] According to some embodiments of this application, a power consumption device is further provided, which includes a battery of any one of the above embodiments, and the battery is used to provide electrical energy to the power consumption device. The power consumption device may be any one of the above devices or systems that utilize a battery cell.

[0318] Referring to Figures 4 to 7, some embodiments of this application provide a cylindrical battery cell 7 which includes an electrode assembly 10, a case 20, electrode terminals 30, a current collector 40, and a cover plate 50.

[0319] The case 20 includes a cylindrical body 21 and a lid 22, which are integrally formed. The cylindrical body 21 is positioned to surround the outer circumference of the electrode assembly 10, and the lid 22 is provided with an electrode extraction hole 221. The end of the cylindrical body 21 that is separated from the lid 22 has an opening 211, 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, 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 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 being mounted in the electrode lead-out hole 221, the terminal body 34 including 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 first through hole 323 being used to inject 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 collector component 40 is welded to the connection portion 32 to form at least one first weld W1, and the current collector component 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, as long as they do not contradict each other, the embodiments and features in this application can be combined with each other.

[0324] Finally, it should be noted that the above embodiments are merely for illustrative purposes and not limiting purposes. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art can still modify the inventions described in the above embodiments or make equivalent substitutions for some of their technical features, and such modifications or substitutions should be understood not to cause the invention to deviate from the spirit and scope of the inventions described in the embodiments of this application.

Claims

1. It is a battery cell, The electrode assembly includes the first tab, A case for housing the electrode assembly, The case includes an electrode terminal that is installed in the case, electrically connected to the first tab, and having 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 the center of the winding. The first through-hole communicates with the second through-hole so that the electrolyte injected through the first through-hole flows into the second through-hole. The present invention further includes a current collector for electrically connecting the electrode terminal and the first tab, The current collector 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. The case comprises a cylindrical body and a lid connected to the cylindrical body, the cylindrical body being positioned to surround the outer circumference of the electrode assembly, the lid being provided with electrode lead-out holes, and the electrode terminals being installed in the electrode lead-out holes, wherein the battery cell.

2. The battery cell according to claim 1, wherein the electrode terminals are electrically connected to the first tab by at least one first weld.

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

7. The battery cell according to claim 6, wherein the circumferential spacing angle of any two adjacent first welds between the first through holes is less than 30°.

8. Each of the first welded portions extends along the radial direction of the first through-hole, as described in claim 6.

9. In the axial direction of the first through hole, the depth of the first weld is h, and in the radial direction of the first through hole, the minimum pitch between the first weld and 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 0.2 ≤ h / d ≤ 0.

5.

11. The battery cell according to claim 9, wherein 1.6 mm ≤ d ≤ 5.5 mm.

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

13. The battery cell according to claim 1, wherein 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.

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

15. The diameter of the first through hole is D １ The diameter of the second through hole is D ２ And D １ and D ２ 65% ≤ D １ / D ２ A battery cell according to claim 13, satisfying ≤95%.

16. D ２ ≥ D １ The battery cell according to claim 15, wherein the diameter is +0.2 mm.

17. The battery cell according to claim 1, wherein 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.

18. The battery cell according to claim 1, wherein 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.

19. The battery cell according to claim 1, wherein, in the axial direction of the first through-hole, the projection of the first through-hole is located within the projection of the third through-hole, and the projection of the third through-hole is located within the 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 installed coaxially.

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

22. The terminal body includes a recess and a connecting portion located on the side of the recess facing the electrode assembly, the first through hole passing through the connecting portion, and the connecting portion making an electrical connection with the first tab by at least one first welded portion. The battery cell according to claim 21, wherein at least a portion of the seal plate is housed in the recess.

23. The battery cell according to claim 1, wherein the lid and the cylindrical body are integrally molded.

24. The battery cell according to claim 1, wherein the electrode assembly further includes a second tab, the second tab having the opposite polarity to the first tab, and the second tab is electrically connected to the cover.

25. The battery cell according to claim 24, wherein the first tab is located at the end of the electrode assembly toward the electrode terminals, and the second tab is located at the end of the electrode assembly away from the electrode terminals.

26. The battery cell according to claim 24, wherein the second tab is a negative electrode tab, and the base material of the case is steel.

27. The battery cell according to claim 1, wherein the cylindrical body has an opening at the end away from the lid, and the battery cell further includes a cover plate for sealing the opening.

28. A battery comprising a battery cell according to any one of claims 1 to 27.

29. A power consumption device comprising the battery described in claim 28, wherein the battery is used to provide electrical energy.

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