Battery cells, batteries, and electrical devices

Abstract

Embodiments of the present application provide a battery cell, a battery, and an electrical device. The battery cell includes an electrode assembly, a housing, an electrode terminal, and a current collecting member. The electrode assembly includes a first tab. The housing is used to accommodate the electrode assembly. The electrode terminal is disposed in the housing and includes a first recess and a connecting portion located at the bottom of the first recess. The current collecting member is connected to the first tab and welded to the connecting portion. By providing the first recess in the electrode terminal, the thickness of the connecting portion is reduced, thereby reducing the welding power required for welding the connecting portion to the current collecting member, reducing heat generation, lowering the risk of burns to other components, and improving safety.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to application entitled “Battery Cell and Manufacturing Method and Manufacturing System, Battery and Electrical Device” filed on August 23, 2021, with international application number PCT / CN2021 / 114156. The entire contents of that application are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of battery technology, and more particularly, to a battery cell, a battery, and an electrical device. Background Art

[0004] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric bicycles, electric cars, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes, and power tools. Battery cells can include nickel-cadmium battery cells, nickel-metal hydride battery cells, lithium-ion battery cells, and secondary alkaline zinc-manganese battery cells.

[0005] In the development of battery technology, how to improve the safety of battery cells is a research direction in battery technology. Summary of the Invention

[0006] The present application provides a battery cell, a battery, and an electrical device, which can improve the safety of the battery cell.

[0007] In a first aspect, embodiments of the present application provide a battery cell comprising an electrode assembly, a housing, an electrode terminal, and a current collecting member. The electrode assembly includes a first tab. The housing is configured to accommodate the electrode assembly. The electrode terminal is disposed within the housing and includes a first recess and a connecting portion located at the bottom of the first recess. The current collecting member is connected to the first tab and welded to the connecting portion.

[0008] In the above technical solution, the thickness of the connecting portion is reduced by providing the first recess on the electrode terminal, thereby reducing the welding power required for welding the connecting portion to the current collecting component, reducing heat generation, reducing the risk of burning other components, and improving safety.

[0009] In some embodiments, the current collecting member is welded to the connecting portion to form a first welding portion, and in a thickness direction of the connecting portion, the first welding portion extends from a side of the connecting portion away from the current collecting member to at least the interior of the current collecting member.

[0010] In the above technical solution, the first welding portion extends from the connecting portion to the interior of the current collecting member to connect the current collecting member and the connecting portion, thereby reducing the contact resistance between the current collecting member and the electrode terminal and improving the current carrying capacity.

[0011] In some embodiments, in a thickness direction of the connecting portion, the first welding portion does not extend beyond a surface of the current collecting member facing away from the connecting portion.

[0012] In the above technical solution, the first welding portion is spaced a predetermined distance from the surface of the current collecting component away from the connection portion to prevent the current collecting component from being melted through, reduce the risk of metal particles being generated on the surface of the current collecting component away from the connection portion, and improve safety.

[0013] In some embodiments, the housing includes a cylindrical body and a cover connected to the cylindrical body. The cylindrical body is disposed around the periphery of the electrode assembly. The cover is provided with an electrode lead-out hole, and the electrode terminal is mounted in the electrode lead-out hole. The first weld portion and the cover are both annular. The outer diameter of the cover is D0, and the inner diameter of the first weld portion is D1. D1 and D0 satisfy the following: 0.1 ≤ D1 / D0 ≤ 0.6.

[0014] D0 is positively correlated with the diameter of the electrode assembly. A larger D0 indicates a higher electrode assembly capacity and a higher battery cell's requirement for the flow area of ​​the first weld. A smaller D1 indicates a smaller circumference of the first weld and, consequently, a smaller flow area. If D1 / D0 is too small, the flow area of ​​the first weld will be insufficient due to D0 being too large and D1 being too small. This will generate significant heat during charging and discharging, making it difficult to meet the battery cell's requirements for flow capacity and temperature rise during fast charging.

[0015] The larger D1 is, the larger the size of the electrode lead-out hole is, and the smaller the area of ​​the cover is. Similarly, the smaller D0 is, the smaller the area of ​​the cover is. If D1 / D0 is too large, then because D0 is too small and D1 is too large, the cover will be easily deformed when the battery cell vibrates, posing a safety hazard. The cover can serve as an output pole of the battery cell to connect to the busbar. If D1 / D0 is too large, the connection area between the cover and the busbar will be too small, the flow area between the cover and the busbar will be insufficient, and the heat generation at the connection between the cover and the busbar will be too high, making it difficult to meet the battery cell's requirements for flow capacity and temperature rise during fast charging.

[0016] The above technical solution makes 0.1≤D1 / D0≤0.6, so as to meet the requirements of the battery cell on the overcurrent capacity and temperature rise, and improve the safety of the battery cell.

[0017] In some embodiments, the first welding portion is a non-closed structure, and a central angle α of the first welding portion is 180°-330°.

[0018] α is positively correlated with the flow area of ​​the first weld. The smaller α, the smaller the flow area of ​​the first weld, and the higher the heat generated when current flows through the first weld. The above technical solution limits α to 180°-330°, ensuring that the first weld meets the battery cell's requirements for flow capacity and temperature rise. The first weld is an open structure, and the unwelded area between the two circumferential ends of the first weld releases welding stress, reducing stress concentration.

[0019] In some embodiments, the first welding portion is a closed structure to increase the welding area and improve the welding strength and flow capacity of the first welding portion.

[0020] In some embodiments, 0.2≤D1 / D0≤0.4

[0021] In some embodiments, D1 is 5 mm to 14 mm to meet the requirements of the battery cell for overcurrent capability and temperature rise.

[0022] In some embodiments, the cover and the barrel are formed as an integral structure, which can eliminate the process of connecting the cover and the barrel. When the cover and the barrel are electrically connected to the positive or negative electrode of the electrode assembly, since the connection between the cover and the barrel is an integral structure, the resistance at the connection between the cover and the barrel is small, thereby improving the flow capacity. The cover can be used to connect to an external component (such as a busbar component). When the battery cell is subjected to an external impact, the external component may pull the cover, causing the connection between the cover and the barrel to be subjected to force; the above technical solution integrates the cover and the barrel, thereby improving the strength of the connection between the cover and the barrel and reducing the risk of failure of the connection between the cover and the barrel.

[0023] In some embodiments, in a thickness direction of the connection portion, the first welding portion has a size h, and a thickness of a region of the connection portion for welding with the current collecting member is d0. d0 and h satisfy: 1<h / d0≤1.5.

[0024] If h / d0 ≤ 1, the first weld has a low penetration depth and forms entirely within the connection portion, resulting in a cold weld. This prevents the first weld from effectively connecting the current collecting member to the connection portion. For a given d0, a larger h increases the welding power required and the resulting heat generation. If h is too large, the high temperatures generated by welding can easily damage components surrounding the electrode terminal, posing a safety hazard.

[0025] The above technical solution makes 1<h / d0≤1.5, so as to reduce welding heat generation and reduce welding difficulty under the premise of ensuring the connection between the current collecting component and the connecting part.

[0026] In some embodiments, a thickness of a region of the current collecting member for welding with the connection portion is d1, and d0 and d1 satisfy: 0.5≤d1 / d0≤1.2.

[0027] When d0 is constant, the smaller d1 is, the easier it is for the current collecting component to be melted through during welding, and the easier it is for high-temperature particles generated by welding to fall into the battery cell; the larger d1 is, the more space and weight the current collecting component occupies, and the lower the energy density of the battery cell.

[0028] The above technical solution makes 0.5≤d1 / d0≤1.2, so as to reduce the risk of the current collecting member being melted through and reduce the loss of energy density of the battery cell.

[0029] In some embodiments, d0 is 0.4 mm-1.2 mm to meet the requirements of the battery cell for overcurrent capacity and temperature rise, reduce welding heat generation, and improve safety.

[0030] In some embodiments, at least a portion of the first electrode tab is located on a side of the current collecting member facing away from the electrode terminal and is supported by the current collecting member.

[0031] In the above technical solution, the first tab supports the current collecting member, ensuring that it aligns with the connecting portion. When the battery cell vibrates, the first tab limits the movement of the current collecting member relative to the connecting portion, thereby reducing the force on the first weld and the risk of tearing the first weld. During welding of the connecting portion and the current collecting member, the first tab supports the current collecting member, minimizing relative displacement between the two parts and reducing the risk of a cold weld.

[0032] In some embodiments, the first portion of the first electrode tab is located on a side of the connecting portion facing away from the first recess, and is used to support a portion of the current collecting member opposite to the connecting portion.

[0033] In the above technical solution, the first portion can support the portion of the current collecting component opposite the connecting portion, so that the current collecting component and the connecting portion are tightly fitted, reducing the risk of cold welding. During the welding process, the first portion can also limit the deformation of the current collecting component and improve the morphology of the current collecting component.

[0034] In some embodiments, the first portion is welded to the current collecting member and forms a second weld portion.

[0035] In the above technical solution, the second weld portion can reduce the contact resistance between the current collecting member and the first tab, thereby improving the current carrying capacity. The second weld portion is close to the connecting portion, which can reduce the conductive path between the connecting portion and the second weld portion, thereby reducing the resistance and improving the current carrying capacity.

[0036] In some embodiments, the second portion of the first tab surrounds the outer circumference of the first portion and is used to support a region of the current collecting member that is not opposite to the connecting portion.

[0037] In the above technical solution, by providing the second part, the area of ​​the region of the first electrode tab supporting the current collecting member can be increased, the supporting effect of the first electrode tab can be improved, the pressure between the first electrode tab and the current collecting member can be reduced, and the risk of the first electrode tab being crushed can be reduced.

[0038] In some embodiments, the second portion is welded to the current collecting member to form a third weld portion.

[0039] In the above technical solution, the third welding portion can reduce the contact resistance between the current collecting member and the second portion, thereby improving the current carrying capacity.

[0040] In some embodiments, the current collecting member has a protrusion on a side facing the first electrode tab, and the protrusion is welded to the second portion to form a third welding portion.

[0041] In the above technical solution, the convex portion can better fit with the second portion, reducing the risk of poor welding.

[0042] In some embodiments, the first tab is disposed around the central axis of the electrode assembly, and a cross-section of the first tab perpendicular to the central axis is annular. The outer radius of the first tab is R, and the minimum radial distance between the third weld portion and the central axis of the first tab is D2, both of which satisfy the following: 0.2≤D2 / R≤0.8.

[0043] R is positively correlated with the diameter of the electrode assembly. A larger R value results in a greater current generated by the electrode assembly, and the battery cell's flow area requirements are higher. The portion of the current collecting member near the central axis can be used for welding to the connector. As D2 decreases, the area of ​​the current collecting member that can be welded to the connector decreases, and the flow area between the current collecting member and the connector decreases. If D2 / R is too small, then due to a small D2 and a large R value, the flow area between the current collecting member and the connector will be insufficient. The weld between the current collecting member and the connector will generate significant heat during charging and discharging, making it difficult to meet the battery cell's requirements for flow capacity and temperature rise during fast charging.

[0044] The first tab includes multiple tab layers. The larger D2 is, the further outward the tab layer directly connected to the third weld is. If D2 is too large, the number of tab layers connected to the third weld will be too small, and the distance between the third weld and the innermost tab layer will be too large. This will cause a significant difference in the current path between the outermost tab layer and the electrode terminal and the innermost tab layer, resulting in uneven current density in the first electrode sheet and increased internal resistance.

[0045] The above technical solution limits D2 / R to 0.2-0.8, minimizing differences in the current paths between different portions of the first tab and the electrode terminal. This improves the uniformity of the current density in the first electrode sheet of the electrode assembly, reduces internal resistance, and satisfies the battery cell's requirements for current handling and temperature rise.

[0046] In some embodiments, D2 and R satisfy: 0.2≤D2 / R≤0.5.

[0047] In some embodiments, D2 is 3.5 mm to 10 mm to reduce the internal resistance of the electrode assembly and meet the requirements of the battery cell for overcurrent capacity and temperature rise.

[0048] In some embodiments, the diameter of the current collecting member is D3, the diameter of the first electrode tab is D4, and D3 is smaller than D4.

[0049] In the above technical solution, the current collecting component has a smaller diameter, which can save the space and weight occupied by the current collecting component and improve the energy density of the battery cell.

[0050] In some embodiments, D3 and D4 satisfy: 0.75≤D3 / D4≤0.97.

[0051] When D4 is constant, if D3 is too small, the distance between the outer portion of the first tab and the current collecting member is too large, and the conductive path between the outer portion of the first tab and the current collecting member is too long, resulting in a high internal resistance of the electrode assembly and affecting the performance of the battery cell. The above technical solution ensures that D3 / D4 ≥ 0.75, thereby reducing the internal resistance of the electrode assembly and improving the charge and discharge performance of the battery cell.

[0052] When D4 is constant, if D3 is too large, then due to assembly errors, the coaxiality of the current collecting component and the electrode assembly will fluctuate, causing the current collecting component to protrude from the outer peripheral surface of the electrode assembly, making it difficult for the current collecting component and the electrode assembly to enter the shell, affecting assembly efficiency and product quality rate.

[0053] If D3 is too large while D4 is constant, assembly errors can cause fluctuations in the coaxiality between the current collecting member and the electrode assembly, causing the current collecting member to protrude from the outer circumference of the electrode assembly. This makes it difficult to insert the current collecting member and electrode assembly into the housing, affecting assembly efficiency and product quality. The above technical solution ensures that D3 / D4 ≤ 0.97, reducing the risk of the current collecting member protruding from the outer circumference of the electrode assembly due to errors, thereby improving assembly efficiency and product quality.

[0054] In some embodiments, D3 is 35 mm to 44 mm. Limiting D3 to 35 mm to 44 mm can reduce the internal resistance of the electrode assembly, improve the charge and discharge performance of the battery cell, and reduce the risk of the current collecting member protruding from the outer peripheral surface of the electrode assembly due to error.

[0055] In some embodiments, the connection portion is provided with a groove recessed from a first outer surface of the connection portion in a direction facing the electrode assembly, and the first welding portion extends from a bottom wall of the groove at least to an interior of the current collecting member.

[0056] During the production of battery cells, external devices need to be mated to the connection portion. The surface of the first weld portion is uneven, and if an external device is pressed against the first weld portion, the external device is easily crushed by the first weld portion. The above technical solution provides a groove to form a gap between the first outer surface and the bottom wall of the groove. In this way, the first outer surface can be used to support the external device, separating the external device from the first weld portion and reducing the risk of crushing the external device.

[0057] In some embodiments, the housing includes a cylindrical body and a cover connected to the cylindrical body. The cylindrical body is disposed around the periphery of the electrode assembly. The cover is provided with an electrode lead-out hole, and the electrode terminal is mounted in the electrode lead-out hole. The electrode terminal includes a terminal body, which includes a columnar portion, a first retaining portion, and a second retaining portion. At least a portion of the columnar portion is located within the electrode lead-out hole. The first recess is provided in the columnar portion. The first retaining portion and the second retaining portion are both connected to and protrude from the outer wall of the columnar portion. The first retaining portion and the second retaining portion are respectively provided on the outer side and the inner side of the cover and are used to clamp a portion of the cover.

[0058] In the above technical solution, the first limiting portion and the second limiting portion clamp a portion of the cover body from both sides to fix the terminal body to the cover body.

[0059] In some embodiments, the terminal body has a second outer surface, and the first recess is recessed from the second outer surface in a direction facing the electrode assembly to the first outer surface of the connecting portion.

[0060] In some embodiments, the electrode terminal further includes a sealing plate connected to the terminal body and closing an opening of the first recess.

[0061] In the above technical solution, the sealing plate can protect the connection part from the outside, reduce external impurities entering the first recess, reduce the risk of the connection part being damaged by external impurities, and improve the sealing performance of the battery cell.

[0062] In some embodiments, the electrode assembly further includes a second tab having a polarity opposite to that of the first tab, the second tab being disposed around the central axis of the electrode assembly. The first tab is disposed at an end of the electrode assembly facing the electrode terminal, and the second tab is disposed at an end of the electrode assembly facing away from the electrode terminal, the second tab being electrically connected to the housing.

[0063] In the above technical solution, the housing itself can serve as an output electrode for the battery cell, eliminating a traditional electrode terminal and simplifying the battery cell structure. When multiple battery cells are assembled into a group, the housing can be electrically connected to the current collector, which not only increases the flow area but also makes the collector structure more flexible.

[0064] In some embodiments, the second tab is a negative tab, and the base material of the housing is steel. The steel housing is not easily corroded by the electrolyte under low potential conditions.

[0065] In some embodiments, the housing has an opening at one end facing away from the electrode terminal, and the battery cell further includes a cover plate for closing the opening.

[0066] In a second aspect, an embodiment of the present application provides a battery comprising a plurality of battery cells according to any one of the embodiments of the first aspect.

[0067] In a third aspect, an embodiment of the present application provides an electrical device, comprising the battery of the second aspect, the battery being used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0069] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0070] Figure 2 An exploded schematic diagram of a battery provided in some embodiments of the present application;

[0071] Figure 3 for Figure 2 A schematic structural diagram of the battery module shown;

[0072] Figure 4 An exploded schematic diagram of a battery cell provided in some embodiments of the present application;

[0073] Figure 5 A schematic cross-sectional view of a battery cell provided in some embodiments of the present application;

[0074] Figure 6 for Figure 5 A partial enlarged schematic diagram of a battery cell is shown;

[0075] Figure 7 for Figure 6 An enlarged schematic diagram at box B;

[0076] Figure 8 for Figure 7 An enlarged schematic diagram at circle C;

[0077] Figure 9 A schematic diagram of a terminal body of an electrode terminal of a battery cell provided in some embodiments of the present application;

[0078] Figure 10A schematic diagram of a terminal body of an electrode terminal of a battery cell provided in some embodiments of the present application;

[0079] Figure 11 Schematic diagram of the structure of the electrode assembly and current collecting member of the battery cell of some embodiments of the present application;

[0080] Figure 12 Schematic diagrams of the structures of electrode assemblies and current collecting components of battery cells in other embodiments of the present application;

[0081] Figure 13 A partial cross-sectional schematic diagram of a battery cell provided in some other embodiments of the present application;

[0082] Figure 14 for Figure 13 An enlarged schematic diagram at box E;

[0083] Figure 15 An exploded schematic diagram of an electrode terminal of a battery cell provided in some embodiments of the present application;

[0084] Figure 16 A schematic top view of an electrode terminal of a battery cell provided in some embodiments of the present application;

[0085] Figure 17 A partial cross-sectional schematic diagram of a battery cell provided in some other embodiments of the present application;

[0086] Figure 18 A partial cross-sectional schematic diagram of a battery cell provided in some other embodiments of the present application;

[0087] Figure 19 Schematic cross-sectional views of battery cells provided in some other embodiments of the present application.

[0088] In the drawings, the drawings are not drawn to scale. DETAILED DESCRIPTION

[0089] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0090] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0091] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0092] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0093] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0094] 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 in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0095] The term "plurality" used in this application refers to two or more (including two).

[0096] In this application, the term "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; at the same time, "vertical" also includes not only the absolutely vertical situation, but also the roughly vertical situation conventionally recognized in engineering.

[0097] In the present application, battery cells may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells or magnesium-ion battery cells, etc., and the embodiments of the present application are not limited to this.

[0098] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may include a battery module or a battery pack. A battery generally includes a casing that encloses one or more battery cells. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0099] A battery cell comprises an electrode assembly and an electrolyte. The electrode assembly comprises a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet comprises a positive current collector and a positive active material layer, which is coated on the surface of the positive electrode collector. The positive electrode collector comprises a positive current collector portion and a positive tab, which is coated with the positive active material layer, while the positive tab is not. For lithium-ion batteries, for example, the positive current collector can be made of aluminum, and the positive active material layer comprises a positive active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet comprises a negative current collector and a negative active material layer, which is coated on the surface of the negative electrode collector. The negative electrode collector comprises a negative current collector portion and a negative tab, which is coated with the negative active material layer, while the negative tab is not. The negative electrode current collector may be made of copper, and the negative electrode active material layer includes a negative electrode active material, which may be carbon or silicon, etc. The separator may be made of PP (polypropylene) or PE (polyethylene), etc.

[0100] A battery cell also includes a housing for housing the electrode assembly and electrode terminals mounted on the housing. The electrode terminals are electrically connected to the electrode assembly to enable charging and discharging of the electrode assembly. To facilitate assembly and ensure the battery cell's current handling capacity, the battery cell typically connects the electrode assembly's tabs and electrode terminals via current collecting members.

[0101] To reduce resistance and increase flow, the inventors typically use welding to connect the electrode terminals and current collecting components. The inventors noted that if the current collecting components and electrode terminals are welded first before the electrode terminals are mounted on the housing, metal particles generated by the welding process may adhere to the electrode terminals or current collecting components and fall into the housing during assembly. Metal particles that fall into the housing could puncture the separator of the electrode assembly, causing a short circuit risk.

[0102] In order to reduce the amount of metal particles falling into the shell, the inventors tried to first install the electrode terminal on the shell, and then weld the current collecting component and the electrode terminal from the outside of the electrode terminal. In this way, the shell can block the metal particles and reduce the amount of metal particles entering the shell.

[0103] However, during the welding process, the inventors discovered that when welding the electrode terminal and the current collecting member from the outside of the electrode terminal, the electrode terminal needs to be melted through, and the electrode terminal usually has a large thickness, which results in high power required for welding and high heat generated by welding; the heat is conducted to other components, such as seals, electrode assemblies, etc., which can easily damage these components and cause safety hazards.

[0104] In view of this, an embodiment of the present application provides a technical solution by providing a recess on the electrode terminal to reduce the thickness of the portion of the electrode terminal used for welding with the current collecting component, thereby reducing the welding difficulty, reducing welding heat generation, and improving safety.

[0105] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0106] Electrical devices may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. Vehicles may include fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles may include pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0107] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0108] Figure 1 This is a schematic diagram of the structure of a vehicle provided in some embodiments of the present application. Figure 1 As shown, a battery 2 is provided inside the vehicle 1, and the battery 2 can be provided at the bottom, head, or tail of the vehicle 1. The battery 2 can be used to power the vehicle 1, for example, the battery 2 can be used as an operating power source for the vehicle 1.

[0109] The vehicle 1 may further include a controller 3 and a motor 4 . The controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, to meet the power requirements of the vehicle 1 during startup, navigation, and driving.

[0110] In some embodiments of the present application, the battery 2 can not only serve as the operating power source of the vehicle 1, but also serve as the driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0111] Figure 2 Schematic diagram of the explosion of the battery provided in some embodiments of the present application. Figure 2 As shown, the battery 2 includes a box 5 and a battery cell ( Figure 2 The battery cells are housed in the box body 5 .

[0112] The housing 5 is used to house battery cells and can have various structures. In some embodiments, the housing 5 can 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 and the second housing portion 5b together define a storage space 5c for accommodating the battery cells. The second housing portion 5b can be a hollow structure with one end open. The first housing portion 5a is a plate-like structure, and the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. The first housing portion 5a and the second housing portion 5b can also be hollow structures with one end open. The open side of the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. Of course, the first housing portion 5a and the second housing portion 5b can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0113] In order to improve the sealing performance after the first box body 5a and the second box body 5b are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 5a and the second box body 5b.

[0114] Assuming that the first box body portion 5a covers the top of the second box body portion 5b, the first box body portion 5a can also be called an upper box cover, and the second box body portion 5b can also be called a lower box body.

[0115] In battery 2, there can be one or more battery cells. If there are multiple battery cells, they can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections. Multiple battery cells can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire battery module can be housed within housing 5. Alternatively, multiple battery cells can be first connected in series, in parallel, or in a hybrid configuration to form a battery module 6, and then multiple battery modules 6 can be connected in series, in parallel, or in a hybrid configuration to form a single unit housed within housing 5.

[0116] Figure 3 for Figure 2 The schematic diagram of the battery module is shown.

[0117] In some embodiments, as Figure 3As shown, there are multiple battery cells 7, which are first connected in series, in parallel, or in mixed series to form a battery module 6. The multiple battery modules 6 are then connected in series, in parallel, or in mixed series to form a whole, which is accommodated in a box.

[0118] Multiple battery cells 7 in the battery module 6 can be electrically connected via a busbar 8 to achieve parallel, series, or mixed connection of multiple battery cells 7 in the battery module 6. There can be one or more busbars, each of which is used to electrically connect at least two battery cells.

[0119] Figure 4 An exploded schematic diagram of a battery cell provided in some embodiments of the present application; Figure 5 A schematic cross-sectional view of a battery cell provided in some embodiments of the present application; Figure 6 for Figure 5 A partial enlarged schematic diagram of a battery cell is shown; Figure 7 for Figure 6 An enlarged schematic diagram at box B; Figure 8 for Figure 7 Enlarged schematic diagram at circle C.

[0120] like Figures 4 to 8 As shown, a battery cell 7 in some embodiments of the present application includes an electrode assembly 10, a housing 20, an electrode terminal 30, and a current collecting member 40. The electrode assembly 10 includes a first electrode tab 11. The housing 20 is used to accommodate the electrode assembly 10. The electrode terminal 30 is disposed in the housing 20 and includes a first recess 31 and a connecting portion 32 located at the bottom of the first recess 31. The current collecting member 40 is connected to the first electrode tab 11 and welded to the connecting portion 32.

[0121] The electrode assembly 10 includes a first electrode sheet and a second electrode sheet of opposite polarity. One of the first electrode sheet and the second electrode sheet is a positive electrode sheet, and the other is a negative electrode sheet. Exemplarily, the electrode assembly 10 generates electrical energy through oxidation and reduction reactions when ions are inserted into and extracted from the positive and negative electrode sheets. Optionally, the electrode assembly 10 also includes a separator for insulating and isolating the first electrode sheet from the second electrode sheet.

[0122] In some examples, the first electrode piece, the second electrode piece, and the separator are all strip-shaped structures, and the first electrode piece, the second electrode piece, and the separator are wound together around the central axis A to form a wound structure. The wound structure can be a cylindrical structure, a flat structure, or a structure of other shapes. In other examples, the electrode assembly 10 can also be a laminated structure formed by stacking the first electrode piece, the separator, and the second electrode piece.

[0123] The first electrode tab 11 may be a portion of the first electrode sheet that is not coated with the active material layer. The first electrode tab 11 may be a positive electrode tab or a negative electrode tab.

[0124] The housing 20 is a hollow structure, and a space is formed inside it for accommodating the electrode assembly 10. The housing 20 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. The shape of the housing 20 can 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 housing can be selected; if the electrode assembly 10 has a rectangular parallelepiped structure, a rectangular parallelepiped housing can be selected. Optionally, both the electrode assembly 10 and the housing 20 are cylindrical.

[0125] The shell 20 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0126] The housing 20 may be positively charged, negatively charged, or uncharged.

[0127] The electrode terminal 30 can serve as an output electrode of the battery cell 7, which can electrically connect the battery cell 7 to an external circuit to realize charging and discharging of the battery cell 7. Optionally, the electrode terminal 30 is used to connect to a busbar component to realize electrical connection between the battery cells 7.

[0128] The electrode terminal 30 can be insulated and disposed on the housing 20 , or can be electrically connected to the housing 20 . This embodiment of the present application does not limit this, as long as the positive electrode sheet and the negative electrode sheet are prevented from being conductive.

[0129] The first recess 31 may be recessed from the side of the electrode terminal 30 facing away from the electrode assembly 10 in a direction facing the electrode assembly 10 , or may be recessed from the side of the electrode terminal 30 facing the electrode assembly 10 in a direction away from the electrode assembly 10 .

[0130] The connection portion 32 is a portion of the electrode terminal 30 corresponding to the bottom surface of the first recess 31 .

[0131] The current collecting member 40 electrically connects the first electrode tab 11 to the electrode terminal 30. The embodiment of the present application does not limit the connection method between the first electrode tab 11 and the current collecting member 40. For example, the current collecting member 40 can be connected to the first electrode tab 11 by welding, abutting or bonding.

[0132] The current collecting member 40 and the connecting portion 32 are connected by welding. For example, the current collecting member 40 and the connecting portion 32 are connected by laser welding.

[0133] In the embodiment of the present application, the first recess 31 is provided on the electrode terminal 30 to reduce the thickness of the connecting portion 32 , thereby reducing the welding power required for welding the connecting portion 32 to the current collecting component 40 , reducing heat generation, reducing the risk of other components being burned, and improving safety.

[0134] In some embodiments, the electrode assembly 10 includes a main body 12, a first electrode tab 11, and a second electrode tab 13. The first electrode tab 11 and the second electrode tab 13 protrude from the main body 12. The first electrode tab 11 is the portion of the first electrode sheet not coated with the active material layer, and the second electrode tab 13 is the portion of the second electrode sheet not coated with the active material layer.

[0135] The first electrode tab 11 and the second electrode tab 13 may extend from the same side of the main body 12 or from opposite sides thereof. For example, the first electrode tab 11 is located at the end of the electrode assembly 10 facing the electrode terminal 30, and the second electrode tab 13 is located at the end of the electrode assembly 10 facing away from the electrode terminal 30.

[0136] In some embodiments, the first electrode tab 11 is wound multiple times around the central axis A of the electrode assembly 10. In other words, the first electrode tab 11 includes multiple turns of electrode tab layers. After winding, the first electrode tab 11 is generally cylindrical, with a gap between two adjacent turns of electrode tab layers. In embodiments of the present application, the first electrode tab 11 can be processed to reduce the gap between the electrode tab layers, thereby facilitating the connection of the first electrode tab 11 to the current collecting member 40. For example, in embodiments of the present application, the first electrode tab 11 can be flattened to gather and bring together the end regions of the first electrode tab 11 away from the main body 12. The flattening process forms a dense end surface at the end of the first electrode tab 11 away from the main body 12, thereby reducing the gap between the electrode tab layers and facilitating the connection of the first electrode tab 11 to the current collecting member 40. Alternatively, in embodiments of the present application, a conductive material can be filled between two adjacent turns of electrode tab layers to reduce the gap between the electrode tab layers.

[0137] In some embodiments, the second electrode tab 13 is wound multiple times around the central axis A of the electrode assembly 10, and the second electrode tab 13 includes multiple electrode tab layers. Exemplarily, the second electrode tab 13 is also flattened to reduce gaps between the electrode tab layers of the second electrode tab 13.

[0138] The central axis A of the electrode assembly 10 is a virtual straight line. The first electrode sheet, the second electrode sheet, and the separator can be wound around the central axis A.

[0139] In some embodiments, the shell 20 includes a barrel 21 and a cover 22 connected to the barrel 21 . The barrel 21 is arranged around the periphery of the electrode assembly 10 . The cover 22 is provided with an electrode lead-out hole 221 . The electrode terminal 30 is installed in the electrode lead-out hole 221 .

[0140] The cover 22 and the barrel 21 can be an integral structure, that is, the housing 20 is an integrally formed component. Of course, the cover 22 and the barrel 21 can also be two components provided separately and then connected together by welding, riveting, bonding, etc.

[0141] The electrode lead-out hole 221 passes through the cover 22 to facilitate the electrical energy in the electrode assembly 10 to be led out of the shell 20 .

[0142] The central axis A is a virtual straight line that passes through the electrode lead-out hole 221. The central axis A of the electrode assembly 10 and the axis of the electrode lead-out hole 221 may or may not coincide with each other.

[0143] The electrode terminal 30 is used to cooperate with the electrode lead-out hole 221 to cover the electrode lead-out hole 221. The electrode terminal 30 can extend into the electrode lead-out hole 221 or not. The electrode terminal 30 is fixed to the cover 22. The electrode terminal 30 can be fixed as a whole to the outside of the cover 22, or it can extend into the interior of the housing 20 through the electrode lead-out hole 221.

[0144] In some embodiments, the cover 22 and the barrel 21 are formed as an integral structure, which can save the connection process of the cover 22 and the barrel 21.

[0145] When the cover 22 and the barrel 21 are electrically connected to the positive or negative electrode of the electrode assembly 10, the connection between the cover 22 and the barrel 21 is an integrated structure, so the resistance at the connection between the cover 22 and the barrel 21 is low, thereby improving the current flow capacity. The cover 22 can be used to connect to external components (such as a busbar). When the battery cell is subjected to an external impact, the external component may pull on the cover 22, causing force to be applied to the connection between the cover 22 and the barrel 21. The above technical solution integrates the cover 22 and the barrel 21, thereby improving the strength of the connection between the cover 22 and the barrel 21 and reducing the risk of failure of the connection between the cover 22 and the barrel 21.

[0146] In some embodiments, the housing 20 may be formed by a stretching process.

[0147] In some embodiments, the housing 20 has an opening 211 at one end facing away from the electrode terminal 30 , and the battery cell 7 further includes a cover plate 50 for closing the opening 211 .

[0148] Specifically, the cylinder 21 has an opening at one end away from the cover 22, and the cover 50 covers the opening of the cylinder 21 to close the opening of the cylinder 21. The cover 50 can be of various structures, for example, the cover 50 is a plate-shaped structure.

[0149] In some embodiments, the cover plate 50 may be a circular cover plate, a rectangular cover plate, a square cover plate, a hexagonal cover plate, or a cover plate of other shapes.

[0150] In some embodiments, the cover plate 50 is welded to the cylinder 21 .

[0151] In some embodiments, the cover 22 is circular and the electrode assembly 10 is cylindrical; the central axis A coincides with the axis of the electrode lead-out hole 221. This embodiment does not require that the central axis A and the axis of the electrode lead-out hole 221 completely coincide; a process-allowed deviation may exist between the two.

[0152] In this embodiment, the electrode lead-out hole 221 is generally opened in the middle of the cover 22. Accordingly, the electrode terminal 30 is also installed in the middle of the cover 22. When multiple battery cells 7 are assembled into a group, the positioning accuracy requirement of the electrode terminal 30 can be reduced, simplifying the assembly process.

[0153] Exemplarily, the axis of the electrode lead-out hole 221 coincides with the axis of the cover 22 , and the cover 22 is an annular structure disposed around the axis of the electrode lead-out hole 221 .

[0154] Exemplarily, the axis of the electrode terminal 30 coincides with the axis of the electrode lead-out hole 221 .

[0155] In other embodiments, the cover 22 may be rectangular and the electrode assembly 10 may be flat. The electrode lead-out hole 221 may be disposed near an end of the cover 22 along its length.

[0156] In some embodiments, the electrode assembly 10 further includes a second electrode tab 13 having a polarity opposite to that of the first electrode tab 11. The second electrode tab 13 is disposed around the central axis A of the electrode assembly 10. The first electrode tab 11 is disposed at an end of the electrode assembly 10 facing the electrode terminal 30, and the second electrode tab 13 is disposed at an end of the electrode assembly 10 facing away from the electrode terminal 30. The second electrode tab 13 is electrically connected to the housing 20.

[0157] The housing 20 itself can serve as an output electrode of the battery cell 7, thereby eliminating a traditional electrode terminal and simplifying the structure of the battery cell 7. When multiple battery cells 7 are assembled into a group, the housing 20 can be electrically connected to the busbar, which can not only increase the flow area but also make the busbar structure more flexible.

[0158] In some embodiments, the second tab 13 is a negative tab, and the base material of the housing 20 is steel. The housing 20 is electrically connected to the negative tab, that is, the housing 20 is in a low potential state. The steel housing 20 is not easily corroded by the electrolyte in the low potential state.

[0159] In some embodiments, the barrel 21 is used to connect the second electrode tab 13 and the cover 22 so that the second electrode tab 13 and the cover 22 are electrically connected.

[0160] The barrel 21 may be directly electrically connected to the second electrode tab 13 or may be electrically connected to the second electrode tab 13 through other components. For example, the second electrode tab 13 may be electrically connected to the barrel 21 through the cover plate 50 .

[0161] The cover 22 and the electrode terminal 30 have different polarities. In this case, one of the cover 22 and the electrode terminal 30 can serve as the positive output terminal of the battery cell 7, while the other can serve as the negative output terminal of the battery cell 7. In this embodiment, the positive and negative output terminals are arranged on the same side of the battery cell 7, which simplifies the connection process between multiple battery cells 7.

[0162] The electrode lead-out hole 221 in the embodiment of the present application is formed after the shell 20 is stretched.

[0163] The inventors have tried to roll the open end of the cylinder so that the open end of the cylinder is folded inward and forms a flange structure. The flange structure presses the cover plate to fix the cover plate. The inventors installed the electrode terminals on the cover plate and used the flange structure and electrode terminals as the two output poles of the battery cell. However, the larger the size of the flange structure, the higher the risk of curling and wrinkling after forming; if the flange structure curls and wrinkles, it will cause the surface of the flange structure to be uneven, and when the flange structure is welded to the external current collecting component, there will be problems with poor welding. Therefore, the size of the flange structure is relatively limited, resulting in insufficient current capacity of the battery cell.

[0164] In this embodiment, a hole-forming process is used to form electrode lead-out holes 221 on the cover 22 for mounting the electrode terminals 30. This allows the positive and negative output electrodes to be positioned at the end of the battery cell 7 facing away from the opening of the barrel 21. The cover 22 is formed during the molding process of the housing 20. Even after the electrode lead-out holes 221 are formed, the flatness of the cover 22 is maintained, ensuring the connection strength between the cover 22 and the current collector. Furthermore, the flatness of the cover 22 is not constrained by its own dimensions, allowing it to be larger, thereby improving the current handling capacity of the battery cell 7.

[0165] In some embodiments, the current collecting member 40 is welded to the connection portion 32 to form a first weld portion W1 . In the thickness direction X of the connection portion 32 , the first weld portion W1 extends from a side of the connection portion 32 away from the current collecting member 40 to at least the interior of the current collecting member 40 .

[0166] During welding, a portion of the connection portion 32 and a portion of the current collecting member 40 melt to form a molten pool, which solidifies to form a first weld portion W1. For example, after the electrode assembly 10 and the current collecting member 40 are installed in the housing 20 and the current collecting member 40 is pressed against the connection portion 32, external welding equipment can weld the connection portion 32 and the current collecting member 40 from the side of the connection portion 32 facing away from the current collecting member 40, forming the first weld portion W1. The first weld portion W1 is exposed on the surface of the connection portion 32 facing away from the current collecting member 40.

[0167] The embodiment of the present application does not impose any particular restrictions on the shape, position, depth, or number of the first welding portion W1. For example, the shape of the first welding portion W1 can be linear, angular, annular, spiral, V-shaped, or other shapes. The first welding portion W1 can be one or more.

[0168] The first welding portion W1 may penetrate the current collecting member 40. For example, the first welding portion W1 penetrates the current collecting member 40 and the connecting portion 32, and the first welding portion W1 is exposed on the surface of the current collecting member 40 facing away from the connecting portion 32. Of course, the first welding portion W1 may not penetrate the current collecting member 40, that is, the first welding portion W1 is not exposed on the surface of the current collecting member 40 facing away from the connecting portion 32.

[0169] The first welding portion W1 extends from the connection portion 32 to the interior of the current collecting member 40 to connect the current collecting member 40 and the connection portion 32 , thereby reducing contact resistance between the current collecting member 40 and the electrode terminal 30 and improving current flow capacity.

[0170] In some embodiments, in the thickness direction X of the connection portion 32 , the first welding portion W1 does not extend beyond the surface of the current collecting member 40 facing away from the connection portion 32 .

[0171] The first welding portion W1 is spaced a predetermined distance from the surface of the current collecting member 40 away from the connection portion 32 to prevent the current collecting member 40 from being melted through, reduce the risk of metal particles being generated on the surface of the current collecting member 40 away from the connection portion 32, and improve safety.

[0172] In some embodiments, the housing 20 includes a cylindrical body 21 and a cover 22 connected to the cylindrical body 21. The cylindrical body 21 is arranged around the outer circumference of the electrode assembly 10. The cover 22 is provided with an electrode lead-out hole 221, and the electrode terminal 30 is mounted in the electrode lead-out hole 221. The first weld portion W1 and the cover 22 are both annular. The outer diameter of the cover 22 is D0, and the inner diameter of the first weld portion W1 is D1. D1 and D0 satisfy the following: 0.1 ≤ D1 / D0 ≤ 0.6.

[0173] The first welding portion W1 can be a closed structure or a non-closed structure. In other words, the first welding portion W1 can be a semicircular ring or a full circular ring.

[0174] D0 is positively correlated with the diameter of the electrode assembly 10. The larger D0 is, the higher the capacity of the electrode assembly 10 is, and the higher the requirement of the battery cell 7 for the flow area of ​​the first welding portion W1 is. The smaller D1 is, the smaller the circumference of the first welding portion W1 is, and the smaller the flow area of ​​the first welding portion W1 is. If D1 / D0 is too small, then because D0 is too large and D1 is too small, the flow area of ​​the first welding portion W1 will be insufficient, and the first welding portion W1 will generate a lot of heat during charging and discharging, making it difficult to meet the flow capacity and temperature rise requirements of the battery cell 7 during fast charging. After in-depth research and a large number of experiments, the inventors found that when D1 / D0 ≥ 0.1, the flow capacity and temperature rise requirements of the battery cell 7 can be met.

[0175] The larger D1 is, the larger the size of the electrode lead-out hole 221 is, and the smaller the area of ​​the cover 22 is. Similarly, the smaller D0 is, the smaller the area of ​​the cover 22 is. If D1 / D0 is too large, then because D0 is too small and D1 is too large, the cover 22 will be easily deformed when the battery cell 7 vibrates, causing a safety hazard. The cover 22 can serve as an output pole of the battery cell 7 to be connected to the busbar. If D1 / D0 is too large, the connection area between the cover 22 and the busbar will be too small, the flow area between the cover 22 and the busbar will be insufficient, and the heat generation at the connection between the cover 22 and the busbar will be too high, making it difficult to meet the requirements of the battery cell 7 for flow capacity and temperature rise during fast charging. After in-depth research and a large number of experiments, the inventors found that when D1 / D0≤0.6, the requirements of the battery cell 7 for flow capacity and temperature rise can be met, thereby improving the safety of the battery cell 7.

[0176] D1 / D0 may be 0.1, 0.2, 0.3, 0.4, 0.5 or 0.6.

[0177] In some embodiments, after in-depth research and extensive experiments, the inventors found that when 0.2≤D1 / D0≤0.4, the requirements of the battery cell 7 for overcurrent capacity and temperature rise can be better met, thereby improving the safety of the battery cell 7.

[0178] In some embodiments, D1 is 5 mm-14 mm.

[0179] If D1 is too small, the flow area of ​​the first weld W1 will be insufficient, generating significant heat during charging and discharging, making it difficult to meet the current handling and temperature rise requirements of the battery cell 7 during fast charging. If D1 is too large, the flow area between the cover 22 and the current collector will be insufficient, resulting in excessive heat generation at the connection between the cover 22 and the current collector. After in-depth research and extensive experimentation, the inventors found that limiting D1 to 5mm-14mm can meet the current handling and temperature rise requirements of the battery cell 7.

[0180] Optionally, D1 is 5 mm, 7 mm, 9 mm, 10 mm, 12 mm or 14 mm.

[0181] In some embodiments, in the thickness direction X of the connection portion 32 , the first welding portion W1 has a size h, and a thickness d0 of a region of the connection portion 32 for welding with the current collecting member 40 . d0 and h satisfy: 1<h / d0≤1.5.

[0182] The first weld W1 is annular, and due to process errors, different regions of the first weld W1 may have different penetration depths in the thickness direction X. h may be the size of the region of the first weld W1 with the smallest penetration depth along the thickness direction X.

[0183] In some examples, the connecting portion 32 is a flat plate structure with uniform thickness, and any portion of the connecting portion 32 can be used for welding to the current collecting member 40, where d0 is the thickness of the connecting portion 32. In other examples, the connecting portion 32 is a structure with uneven thickness, and the region of the connecting portion 32 with smaller thickness can be used for welding to the current collecting member 40, thereby reducing the power required for welding and reducing heat generation. For example, the connecting portion 32 can be locally reduced in thickness by providing a groove, and the region of the connecting portion 32 corresponding to the groove can be used as the region of the connecting portion 32 for welding to the current collecting member 40.

[0184] If h / d0 ≤ 1, the first weld W1 has a low penetration depth and is formed entirely within the connecting portion 32, resulting in a cold weld. This prevents the first weld W1 from effectively connecting the current collecting member 40 to the connecting portion 32. For a given d0, a larger h increases the welding power required and the resulting heat generation. If h is too large, the high temperature generated by welding can easily damage components surrounding the electrode terminal 30, posing a safety hazard.

[0185] After in-depth research and numerous experiments, the inventors found that when 1<h / d0≤1.5, welding heat generation can be reduced and welding difficulty can be lowered while ensuring the connection between the current collecting member 40 and the connecting portion 32 .

[0186] Optionally, h / d0 is 1.05, 1.1, 1.2, 1.3, 1.4 or 1.5.

[0187] In some embodiments, the thickness of the region of the current collecting member 40 for welding with the connection portion 32 is d1, and d0 and d1 satisfy: 0.5≤d1 / d0≤1.2.

[0188] The region of the current collecting member 40 for welding with the connection portion 32 refers to a region of the current collecting member 40 that abuts against the connection portion 32 .

[0189] When d0 is constant, the smaller d1 is, the easier it is for the current collecting member 40 to be melted through during welding, and the easier it is for high-temperature particles generated by welding to fall into the battery cell 7; the larger d1 is, the greater the space and weight occupied by the current collecting member 40, and the lower the energy density of the battery cell 7.

[0190] After in-depth research and numerous experiments, the inventors found that when 0.5≤d1 / d0≤1.2, the risk of the current collecting member 40 being melted through can be reduced, and the loss of energy density of the battery cell 7 can be reduced.

[0191] Optionally, d1 / d0 is 0.5, 0.7, 0.9, 1.0 or 1.2.

[0192] In some embodiments, d0 is 0.4 mm-1.2 mm.

[0193] The smaller d0 is, the lower the current capacity of the connection portion 32 is. If d0 is too small, the connection portion 32 may not meet the current capacity and temperature rise requirements of the battery cell 7 during fast charging. The larger d0 is, the greater the welding power required and the higher the heat generated during welding. If d0 is too large, the high temperature generated by welding can easily damage components around the electrode terminal 30, posing a safety hazard.

[0194] After in-depth research and extensive experiments, the inventors found that limiting d0 to 0.4 mm-1.2 mm can meet the requirements of the battery cell 7 for overcurrent capacity and temperature rise, reduce welding heat generation, and improve safety.

[0195] Optionally, d0 is 0.4 mm, 0.5 mm, 0.6 mm, 0.8 mm, 1.0 mm or 1.2 mm.

[0196] Alternatively, after in-depth research and extensive experiments, the inventors found that limiting d0 to 0.6 mm to 1.0 mm can better meet the battery cell 7's requirements for current capacity and temperature rise, reduce welding heat generation, and improve safety.

[0197] In some embodiments, d1 is 0.2 mm to 0.6 mm. Alternatively, d1 is 0.3 mm to 0.5 mm.

[0198] In some embodiments, at least a portion of the first electrode tab 11 is located on a side of the current collecting member 40 facing away from the electrode terminal 30 and is supported by the current collecting member 40 .

[0199] The first electrode tab 11 supports the current collecting member 40 so that the current collecting member 40 is aligned with the connecting portion 32. When the battery cell 7 vibrates, the first electrode tab 11 limits the movement of the current collecting member 40 relative to the connecting portion 32, thereby reducing the force on the first weld portion W1 and the risk of tearing the first weld portion W1.

[0200] During the assembly of the battery cell 7 , the first tab 11 can support the current collecting member 40 so that the current collecting member 40 fits tightly against the connecting portion 32 , thereby reducing the relative displacement between the current collecting member 40 and the connecting portion 32 during welding and lowering the risk of cold welding.

[0201] In some embodiments, the first portion 111 of the first electrode tab 11 is located on a side of the connecting portion 32 away from the first recess 31 and is used to support a portion of the current collecting member 40 opposite to the connecting portion 32 .

[0202] The first portion 111 is disposed opposite to the connecting portion 32 in the thickness direction X of the connecting portion 32 . In other words, the first portion 111 is a portion of the first electrode tab 11 that overlaps with the connecting portion 32 in the thickness direction X.

[0203] The first portion 111 can support the portion of the current collecting member 40 opposite the connecting portion 32, so that the current collecting member 40 and the connecting portion 32 are closely fitted, reducing the risk of cold welding. During the welding process, the first portion 111 can also limit the deformation of the current collecting member 40 and improve the morphology of the current collecting member 40.

[0204] In some embodiments, the second portion 112 of the first electrode tab 11 surrounds the outer circumference of the first portion 111 and is used to support an area of ​​the current collecting member 40 that is not opposite to the connecting portion 32 .

[0205] The second portion 112 is a portion of the first electrode tab 11 that does not overlap with the connecting portion 32 in the thickness direction X. Exemplarily, the second portion 112 is an annular structure.

[0206] The provision of the second portion 112 increases the area of ​​the first electrode tab 11 supporting the current collecting member 40, thereby improving the support effect of the first electrode tab 11, reducing the pressure between the first electrode tab 11 and the current collecting member 40, and lowering the risk of crushing the first electrode tab 11. When welding the connecting portion 32 and the current collecting member 40, the second portion 112 supports the current collecting member 40, thereby reducing the relative displacement between the current collecting member 40 and the connecting portion 32 during the welding process and reducing the risk of a cold weld.

[0207] In some embodiments, in the thickness direction X of the connecting portion 32 , the entire first electrode tab 11 may not be opposite to the connecting portion 32 . In other words, the first electrode tab 11 may only include the second portion 112 .

[0208] In some embodiments, the second portion 112 is welded to the current collecting member 40 and forms a third welding portion W3 .

[0209] When assembling the battery cell 7, the second portion 112 of the first electrode tab 11 of the electrode assembly 10 can be welded to the current collecting member 40 first, and then the electrode assembly 10 and the current collecting member 40 can be placed into the housing 20. Specifically, when welding the second portion 112 to the current collecting member 40, the current collecting member 40 can be pressed against the flattened end surface of the first electrode tab 11. Then, an external welding device can emit a laser on the surface of the current collecting member 40 facing away from the first electrode tab 11, and the laser welds the current collecting member 40 to the second portion 112 of the first electrode tab 11.

[0210] The shape of the third welding portion W3 can be linear, C-shaped, annular, spiral, V-shaped or other shapes, which are not limited in this embodiment. The third welding portion W3 can be one or more.

[0211] The third welding portion W3 can reduce the contact resistance between the current collecting member 40 and the second portion 112 , thereby improving the current flow capacity.

[0212] In some embodiments, the current collecting member 40 has a protrusion 41 on a side facing the first electrode tab 11 , and the protrusion 41 is welded to the second portion 112 to form a third weld portion W3 .

[0213] When assembling the current collecting member 40 and the electrode assembly 10, the convex portion 41 of the current collecting member 40 is first pressed against the second portion 112, and then the convex portion 41 and the second portion 112 are welded. The convex portion 41 can better fit the second portion 112, reducing the risk of poor welding.

[0214] In some embodiments, the protrusion 41 may press against the second portion 112 and be embedded in the second portion 112 .

[0215] In some embodiments, except for the protrusion 41 , the rest of the current collecting member 40 is substantially a flat plate structure.

[0216] In some embodiments, the current collecting member 40 has a second recess 42 formed at a position corresponding to the protrusion 41. The second recess 42 is recessed relative to the surface of the current collecting member 40 facing away from the first electrode tab 11, in a direction facing the first electrode tab 11. A transition portion is formed between the bottom surface of the second recess 42 and the top surface of the protrusion 41. The transition portion is welded to the second portion 112 to form a third weld portion W3. The provision of the second recess 42 can reduce the thickness of the transition portion, thereby reducing the welding power required to weld the transition portion to the second portion 112, reducing heat generation, and lowering the risk of burns to the electrode assembly 10.

[0217] The third weld portion W3 is formed by welding and has an uneven surface. In this embodiment, the second recess 42 is provided to recess the surface of the third weld portion W3 relative to the surface of the current collecting member 40 facing away from the first electrode tab 11, thereby avoiding contact between the third weld portion W3 and other components (e.g., the electrode terminal 30).

[0218] In some embodiments, a fixing sheet (not shown) may be disposed within the second recess 42. The fixing sheet is used to cover the third welding portion W3 to secure metal particles remaining on the third welding portion W3, thereby reducing the risk of metal particles falling into the electrode assembly 10 and causing a short circuit. The fixing sheet may be an insulating patch, an insulating adhesive layer, or other structures.

[0219] Figure 9 Schematic diagram of a terminal body of an electrode terminal of a battery cell provided in some embodiments of the present application.

[0220] like Figure 9 As shown, in some embodiments, the first welding portion W1 is a non-closed structure, and the central angle α of the first welding portion W1 is 180°-330°.

[0221] α is positively correlated with the flow area of ​​the first weld W1. The smaller α, the smaller the flow area of ​​the first weld W1, and the higher the heat generated when current flows through the first weld W1. In this embodiment of the application, α is limited to 180°-330° to ensure that the first weld meets the battery cell's requirements for flow capacity and temperature rise.

[0222] The first welding portion W1 is a non-closed structure, and the unwelded area between the two ends of the first welding portion W1 along the circumferential direction can release welding stress and reduce stress concentration.

[0223] Figure 10 Schematic diagram of a terminal body of an electrode terminal of a battery cell provided in some embodiments of the present application.

[0224] like Figure 10 As shown, in some embodiments, the first weld portion W1 is a closed structure. In other words, the central angle of the first weld portion W1 is 360°. This embodiment of the present application can increase the welding area, improve the welding strength and flow capacity of the first weld portion.

[0225] Figure 11 Schematic diagram of the structure of the electrode assembly and current collecting component of the battery cell of some embodiments of the present application.

[0226] Please refer to Figures 6 to 11 In some embodiments, the first electrode tab 11 is disposed around the central axis A of the electrode assembly 10, and a cross-section of the first electrode tab 11 perpendicular to the central axis A is annular. The outer radius of the first electrode tab 11 is R, and the minimum radial distance between the third weld portion W3 and the central axis A in the first electrode tab 11 is D2, and both satisfy the following relationship: 0.2≤D2 / R≤0.8.

[0227] The cross section of the first electrode tab 11 perpendicular to the central axis A is not required to be an absolute circular ring, and a certain deviation is allowed.

[0228] R is positively correlated with the diameter of the electrode assembly 10. The larger R is, the greater the current generated by the electrode assembly 10, and the higher the flow area requirements of the battery cell 7. The portion of the current collecting member 40 near the central axis A can be used for welding to the connection portion 32. The smaller D2 is, the smaller the area of ​​the current collecting member 40 that can be welded to the connection portion 32, and the smaller the flow area between the current collecting member 40 and the connection portion 32. If D2 / R is too small, then due to the small D2 and large R, the flow area between the current collecting member 40 and the connection portion 32 will be insufficient. The weld between the current collecting member 40 and the connection portion 32 will generate a lot of heat during charging and discharging, making it difficult to meet the flow capacity and temperature rise requirements of the battery cell 7 during fast charging.

[0229] The first tab 11 comprises multiple tab layers, each circumscribing a central axis A. In the radial direction of the first tab 11, the multiple tab layers are stacked radially. Current flowing through tab layers directly connected to the third weld W3 can be conducted directly to the current collecting member 40 via the third weld W3. Current flowing through tab layers not connected to the third weld W3 must first be conducted to tab layers directly connected to the third weld W3 before being conducted to the current collecting member 40 via the third weld W3. This results in differences in the conductive paths between the multiple tab layers and the first wall. Excessive differences can easily lead to polarization issues.

[0230] If D2 / R is too small, the distance between the third welding portion W3 and the outermost tab layer is too large, resulting in a large difference between the current path between the outermost tab layer and the electrode terminal 30 and the current path between the innermost tab layer and the electrode terminal 30, causing uneven current density of the first pole piece of the electrode assembly 10 and increased internal resistance.

[0231] After in-depth research and numerous experiments, the inventors found that when D2 / R≥0.2, the requirements of the battery cell 7 for overcurrent capability and temperature rise can be met.

[0232] The larger D2 is, the further outward the tab layer directly connected to the third weld W3 is. If D2 is too large, the number of tab layers connected to the third weld W3 will be too small, and the distance between the third weld W3 and the innermost tab layer will be too large. This will cause a large difference in the current path between the outermost tab layer and the electrode terminal 30 and the current path between the innermost tab layer and the electrode terminal 30, resulting in uneven current density in the first electrode sheet and increased internal resistance.

[0233] After in-depth research and a large number of experiments, the inventors found that when D2 / R≤0.8, the difference in current paths between parts at different positions of the first electrode tab 11 and the electrode terminal 30 is reduced, the uniformity of the current density of the first electrode sheet of the electrode assembly 10 is improved, the internal resistance is reduced, and the overcurrent capacity is improved.

[0234] Optionally, D2 / R is 0.2, 0.3, 0.5, 0.7 or 0.8.

[0235] In some embodiments, after in-depth research and numerous experiments, the inventors found that when D2 and R satisfy: 0.2≤D2 / R≤0.5, the overcurrent capability of the battery cell 7 can be better improved and the temperature rise of the battery cell can be reduced.

[0236] In some embodiments, D2 is 3.5 mm-10 mm.

[0237] If D2 is too small, the flow area between the current collecting member 40 and the connecting portion 32 will be insufficient. The weld between the current collecting member 40 and the connecting portion 32 will generate significant heat during charging and discharging, making it difficult to meet the current handling capacity and temperature rise requirements of the battery cell 7 during fast charging. After in-depth research and extensive experiments, the inventors found that when D2 ≥ 3.5 mm, the current handling capacity and temperature rise requirements of the battery cell 7 can be met.

[0238] If D2 is too large, the number of tab layers connected to the third weld W3 will be too small, and the distance between the tab layer near the central axis A and the third weld W3 will be too large, resulting in a high internal resistance of the electrode assembly 10, which will affect the performance of the battery cell 7. After in-depth research and extensive experiments, the inventors found that when D2 ≤ 10 mm, the internal resistance of the electrode assembly 10 can be reduced, improving the charge and discharge performance of the battery cell 7.

[0239] Optionally, D2 is 3.5 mm, 4 mm, 5 mm, 7 mm, 8.5 mm or 10 mm.

[0240] In some embodiments, R is 20 mm-22.8 mm.

[0241] In some embodiments, the third welding portion W3 is annular in shape and has a large flow area, which can improve the uniformity of the current density of the first electrode, reduce internal resistance, and improve flow capacity.

[0242] In some embodiments, the diameter of the current collecting member 40 is D3 , the diameter of the first electrode tab 11 is D4 , and D3 is smaller than D4 .

[0243] D3 refers to the diameter of the outer edge of the current collecting member 40, ie, the outer diameter of the current collecting member 40. D4 refers to the diameter of the outer edge of the first electrode tab 11, ie, the outer diameter of the first electrode tab 11. Exemplarily, D4=2*R.

[0244] The current collecting member 40 has a smaller diameter, which can save space and weight occupied by the current collecting member 40 and improve the energy density of the battery cell 7 .

[0245] In some embodiments, D3 and D4 satisfy: 0.75≤D3 / D4≤0.97.

[0246] When D4 is constant, if D3 is too small, the distance between the outer portion of the first electrode tab 11 and the current collecting member 40 is too large, and the conductive path between the outer portion of the first electrode tab 11 and the current collecting member 40 is too long, resulting in a relatively high internal resistance of the electrode assembly 10, which affects the performance of the battery cell 7. After in-depth research and extensive experiments, the inventors found that when D3 / D4 ≥ 0.75, the internal resistance of the electrode assembly 10 can be reduced, improving the charge and discharge performance of the battery cell 7.

[0247] When D4 is constant, if D3 is too large, assembly errors can cause fluctuations in the coaxiality of the current collecting member 40 and the electrode assembly 10, causing the current collecting member 40 to protrude from the outer circumference of the electrode assembly 10. This makes it difficult to insert the current collecting member 40 and the electrode assembly 10 into the housing, affecting assembly efficiency and product quality. After in-depth research and extensive experiments, the inventors discovered that when D3 / D4 ≤ 0.97, the risk of the current collecting member 40 protruding from the outer circumference of the electrode assembly 10 due to errors can be reduced, thereby improving assembly efficiency and product quality.

[0248] Alternatively, D3 / D4 may be 0.75, 0.8, 0.85, 0.9, 0.95 or 0.97.

[0249] In some embodiments, D3 is 35 mm to 44 mm. After in-depth research and extensive experiments, the inventors found that limiting D3 to 35 mm to 44 mm can reduce the internal resistance of the electrode assembly 10, improve the charge and discharge performance of the battery cell 7, and reduce the risk of the current collecting member 40 protruding from the outer peripheral surface of the electrode assembly 10 due to errors.

[0250] Alternatively, D3 may be 35 mm, 38 mm, 40 mm, 41 mm, 43 mm or 44 mm.

[0251] In some embodiments, after in-depth research and numerous experiments, the inventors found that limiting D3 to 38 mm-41 mm can better reduce the internal resistance of the electrode assembly 10 and improve the charge and discharge performance of the battery cell 7 .

[0252] In some embodiments, the connection portion 32 is provided with a groove 324 recessed from the first outer surface 322 of the connection portion 32 in a direction facing the electrode assembly 10 , and the first welding portion W1 extends from the bottom wall of the groove 324 at least to the interior of the current collecting member 40 .

[0253] The connecting portion 32 has a first outer surface 322 and a first inner surface 321 disposed opposite to each other along its thickness direction X. The first inner surface 321 faces the current collecting member 40, and the first outer surface 322 faces away from the current collecting member 40. Optionally, both the first outer surface 322 and the first inner surface 321 are planes.

[0254] The groove 324 is recessed relative to the first outer surface 322 in a direction facing the current collecting member 40. In this embodiment, the groove 324 is formed on the connecting portion 32 to form a stepped structure. A gap is formed between the first outer surface 322 and the bottom wall of the groove 324.

[0255] The portion between the bottom wall of the groove 324 and the first inner surface 321 may be an area of ​​the connection portion 32 for welding with the current collecting member 40 . In other words, the portion between the bottom wall of the groove 324 and the first inner surface 321 is used to be welded to the current collecting member 40 to form a first welding portion W1 .

[0256] During the production of battery cells 7, external devices need to be mated to the connection portion 32. The surface of the first welding portion W1 is uneven, and if an external device is pressed against the first welding portion W1, the external device may be easily crushed by the first welding portion W1. In this embodiment, the groove 324 is provided to form a gap between the first outer surface 322 and the bottom wall of the groove 324. In this way, the first outer surface 322 can be used to support the external device, separating the external device from the first welding portion W1 and reducing the risk of crushing the external device.

[0257] For example, the external equipment may be a liquid injection device, a gas extraction device, a welding device, or other equipment used for the battery cell 7 .

[0258] In some embodiments, a first through hole 323 is provided on the connecting portion 32 . The first through hole 323 is used to connect the space on the side of the connecting portion 32 away from the electrode assembly 10 to the internal space of the shell 20 .

[0259] The first through hole 323 passes through the connecting portion 32 along the thickness direction X of the connecting portion 32. There may be one or more first through holes 323.

[0260] When welding the connection portion 32 and the current collecting member 40 , the first through holes 323 can release welding stress and reduce the risk of the connection portion 32 being broken.

[0261] During the molding process of the battery cell 7 , the first through hole 323 may be used in multiple molding steps. For example, the first through hole 323 may be used in a liquid injection step, a formation step, or other steps.

[0262] Specifically, the first through hole 323 is used to inject electrolyte into the interior space of the housing 20 . When injection is required, the injection head of the injection device presses against the connecting portion 32 , and then the injection head injects electrolyte into the housing 20 through the first through hole 323 .

[0263] During the formation process of the battery cell 7 , gas is generated in the housing 20 . The first through hole 323 can also be used to communicate with an external negative pressure device to extract the gas in the housing 20 .

[0264] In some embodiments, the axis of the first through hole 323 coincides with the axis of the electrode lead-out hole 221 .

[0265] In some embodiments, the current collecting member 40 is provided with a second through hole 45 , which is arranged opposite to the first through hole 323 , so that the electrolyte can flow into the inner space of the housing 20 through the second through hole 45 .

[0266] The axial direction of the first through hole 323 is parallel to the axial direction of the second through hole 45. In the axial direction 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 45. This embodiment does not limit the aperture of the second through hole 45, which can be greater than, equal to, or smaller than the aperture of the first through hole 323.

[0267] In this embodiment, a second through hole 45 opposite to the first through hole 323 is provided on the current collecting member 40 to reduce the obstruction of the electrolyte by the current collecting member 40 during the injection process, so that the electrolyte can flow smoothly into the shell 20 and improve the wetting efficiency of the electrode assembly 10.

[0268] In some embodiments, the projection of the first through hole 323 is located within the projection of the second through hole 45 in the axial direction of the first through hole 323. This embodiment can prevent the current collecting member 40 from blocking the first through hole 323, allowing the electrolyte to flow smoothly into the housing 20.

[0269] The first through hole 323 and the second through hole 45 are coaxially arranged, and the aperture of the second through hole 45 may be greater than or equal to the aperture of the first through hole 323 .

[0270] In some embodiments, the electrode assembly 10 is a winding structure, and the electrode assembly 10 has a third through hole 14 at the center of the winding. The third through hole 14 passes through the electrode assembly 10. The third through hole 14 is arranged opposite to the first through hole 323 and the second through hole 45, so that the electrolyte can flow into the interior of the electrode assembly 10 through the third through hole 14.

[0271] The electrode assembly 10 is manufactured by winding the first electrode sheet, the second electrode sheet, and the separator on a winding tool. After the winding is completed, the winding tool is removed from the electrode assembly 10. After the winding tool is removed, a third through hole 14 is formed in the middle of the electrode assembly 10.

[0272] The axial direction of the third through hole 14 may be parallel to the axial direction of the first through hole 323. The axis of the third through hole 14 coincides with the central axis A of the electrode assembly 10. The third through hole 14 passes through the first electrode tab 11, the main body 12 and the second electrode tab 13.

[0273] During the injection process, the electrolyte can flow into the third through hole 14 through the first through hole 323 and the second through hole 45 . The electrolyte flowing into the third through hole 14 can infiltrate the electrode assembly 10 from the inside, thereby improving the infiltration efficiency of the electrode assembly 10 .

[0274] In some embodiments, in the axial direction of the third through hole 14 , the projection of the second through hole 45 is located within the projection of the third through hole 14 . This can reduce the obstruction of the second through hole 45 by the first tab 11 , allowing the electrolyte to flow smoothly into the third through hole 14 .

[0275] In some embodiments, the first through hole 323 , the second through hole 45 , and the third through hole 14 are coaxially arranged. The diameter of the third through hole 14 may be greater than or equal to the diameter of the second through hole 45 .

[0276] In some embodiments, the first through hole 323 extends from the bottom wall of the groove 324 to the first inner surface 321, thereby penetrating the connecting portion 32. During injection, the injection head presses against the first outer surface 322, which supports the injection head and cooperates with the injection head to achieve a seal, reducing the risk of electrolyte leakage outside the battery cell 7.

[0277] Figure 12 Schematic diagrams of the structures of electrode assemblies and current collecting components of battery cells according to other embodiments of the present application.

[0278] like Figure 12 As shown, there are multiple third welding portions W3 , and the multiple third welding portions W3 are arranged at intervals along the circumferential direction Y of the first electrode tab 11 .

[0279] The third welding portion W3 may be a linear structure extending along the radial direction of the electrode assembly 10 , or may be a V-shaped structure, or of course, may be other structures.

[0280] The plurality of third welding portions W3 can increase the flow area, improve the uniformity of the current density of the first electrode, reduce the internal resistance, and improve the flow capacity.

[0281] Figure 13 A partial cross-sectional schematic diagram of a battery cell provided in some other embodiments of the present application is shown. Figure 14 for Figure 13 Enlarged schematic diagram at box E.

[0282] like Figure 13 and Figure 14As shown, in some embodiments, the first portion 111 is welded to the current collecting member 40 and forms a second welding portion W2 .

[0283] The second weld portion W2 can reduce the contact resistance between the current collecting member 40 and the first tab 11, thereby improving the current carrying capacity. The second weld portion W2 is close to the connecting portion 32, which can reduce the conductive path between the connecting portion 32 and the second weld portion W2, thereby reducing resistance and improving the current carrying capacity.

[0284] In some embodiments, the first welding portion W1 and the second welding portion W2 are connected as one body. The current on the first electrode tab 11 can be conducted to the electrode terminal 30 via the second welding portion W2 and the first welding portion W1, thereby shortening the conductive path, reducing resistance, and improving current flow capacity.

[0285] In some embodiments, when welding the connection portion 32 and the current collecting member 40 , the current collecting member 40 may be melted through, and the first welding portion W1 and the second welding portion W2 may be formed simultaneously.

[0286] Figure 15 An exploded schematic diagram of an electrode terminal of a battery cell provided in some embodiments of the present application; Figure 16 Schematic top view of the electrode terminals of a battery cell provided in some embodiments of the present application.

[0287] Please refer to Figures 13 to 16 In some embodiments, the housing 20 includes a cylindrical body 21 and a cover 22 connected to the cylindrical body 21. The cylindrical body 21 is arranged around the outer circumference of the electrode assembly 10. The cover 22 is provided with an electrode lead-out hole 221, and the electrode terminal 30 is installed in the electrode lead-out hole 221. The electrode terminal 30 includes a terminal body 34. The terminal body 34 includes a columnar portion 341, a first limiting portion 342, and a second limiting portion 343. At least a portion of the cylindrical portion 341 is located in the electrode lead-out hole 221. The first recess 31 is provided in the cylindrical portion 341. The first limiting portion 342 and the second limiting portion 343 are both connected to and protrude from the outer wall of the cylindrical portion 341. The first limiting portion 342 and the second limiting portion 343 are respectively provided on the outer side and the inner side of the cover 22 and are used to clamp a portion of the cover 22.

[0288] The first limiting portion 342 is arranged on the outer side of the cover body 22, which means that the first limiting portion 342 is arranged on the side of the cover body 22 away from the electrode assembly 10; the second limiting portion 343 is arranged on the inner side of the cover body 22, which means that the second limiting portion 343 is arranged on the side of the cover body 22 facing the electrode assembly 10.

[0289] In the thickness direction of the cover 22, at least a portion of the first limiting portion 342 overlaps with the cover 22, and at least a portion of the second limiting portion 343 overlaps with the cover 22. The columnar portion 341 passes through the electrode lead-out hole 221 to connect the first limiting portion 342 and the second limiting portion 343 located on both sides of the cover 22.

[0290] The first and second limiting portions 342, 343 clamp a portion of the cover 22 from both sides to fix the terminal body 34 to the cover 22. The first and second limiting portions 342, 343 can clamp the cover 22 directly or indirectly through other components.

[0291] Optionally, the columnar portion 341 is cylindrical. The first limiting portion 342 and the second limiting portion 343 are both annular structures surrounding the columnar portion 341.

[0292] In some embodiments, the battery cell 7 further includes a first insulating member 60 and a second insulating member 70. At least a portion of the first insulating member 60 is disposed between the first limiting portion 342 and the cover 22, and at least a portion of the second insulating member 70 is disposed between the second limiting portion 343 and the cover 22. The first insulating member 60 and the second insulating member 70 are used to insulate and isolate the terminal body 34 from the cover 22.

[0293] The first insulating member 60 and the second insulating member 70 are both annular structures disposed around the columnar portion 341 .

[0294] The first insulating member 60 can insulate and isolate the first limiting portion 342 from the cover 22 , and the second insulating member 70 can insulate and isolate the second limiting portion 343 from the cover 22 .

[0295] In some embodiments, one of the first insulating member 60 and the second insulating member 70 separates the columnar portion 341 from the cover 22. For example, a portion of the first insulating member 60 extends into the electrode lead-out hole 221 to separate the hole wall of the electrode lead-out hole 221 from the columnar portion 341.

[0296] In some embodiments, the first insulating member 60 and the second insulating member 70 are integrally formed. Alternatively, in other embodiments, the first insulating member 60 and the second insulating member 70 are provided separately and abut against each other.

[0297] In some embodiments, one of the first insulating member 60 and the second insulating member 70 is used to seal the electrode lead-out hole 221. In some examples, the first stopper 342 and the cover 22 press the first insulating member 60, compressing and sealing the electrode lead-out hole 221 from the outside. In other examples, the second stopper 343 and the cover 22 press the second insulating member 70, compressing and sealing the electrode lead-out hole 221 from the inside.

[0298] In some embodiments, the battery cell 7 further includes a sealing ring 80, which is sleeved on the columnar portion 341 and is used to seal the electrode lead-out hole 221. Optionally, a portion of the sealing ring 80 extends into the electrode lead-out hole 221 to separate the hole wall of the electrode lead-out hole 221 from the columnar portion 341.

[0299] In some embodiments, a plurality of protrusion structures 342 a are provided on the outer periphery of the first limiting portion 342 , and the plurality of protrusion structures 342 a are arranged at intervals along the circumference of the columnar portion 341 .

[0300] Optionally, the plurality of protruding structures 342 a may be arranged at equal intervals along the circumference of the columnar portion 341 .

[0301] The first limiting portion 342 is a flange structure formed by folding outwardly the end of the terminal body 34 away from the electrode assembly 10 .

[0302] Before the terminal body 34 is assembled into the housing 20, the first stopper 342 of the terminal body 34 is generally cylindrical and located at the upper end of the columnar portion 341. The outer wall of the first stopper 342 is flush with the outer wall of the columnar portion 341. When assembling the terminal body 34 and the housing 20, the first stopper 342 is passed through the electrode lead-out hole 221 and then squeezed to fold outward. The terminal body 34 is then riveted to the cover 22.

[0303] Before the first stopper 342 is folded, a plurality of spaced grooves 342b are formed at its upper end. After the first stopper 342 is folded, a plurality of spaced protrusions 342a are formed along the circumference of the columnar portion 341. The grooves 342b are formed between adjacent protrusions 342a. In this embodiment, the provision of the grooves 342b and protrusions 342a reduces the difficulty of folding the first stopper 342 and reduces stress concentration on the first stopper 342.

[0304] In some embodiments, the second stopper 343 is a stopper structure formed by compressing the end of the terminal body 34 facing the electrode assembly 10 so that the end of the terminal body 34 facing the electrode assembly 10 extends outward. When the cover 22 and the terminal body 34 are assembled, an external device can compress the end of the terminal body 34 facing the electrode assembly 10, and the end of the terminal body 34 facing the electrode assembly 10 extends outward under the action of pressure to form a protruding second stopper 343.

[0305] In some embodiments, the terminal body 34 has a second outer surface 344 , and the first recess 31 is recessed from the second outer surface 344 in a direction facing the electrode assembly 10 to the first outer surface 322 of the connecting portion 32 .

[0306] The terminal body 34 has a second outer surface 344 and a second inner surface 345 that are opposite to each other. The second inner surface 345 faces the electrode assembly 10, and the second outer surface 344 faces away from the electrode assembly 10. The first recess 31 is recessed from the second outer surface 344 in a direction facing the electrode assembly 10 to the first outer surface 322 of the connecting portion 32.

[0307] In some embodiments, the electrode terminal 30 further includes a sealing plate 33 connected to the terminal body 34 and closing the opening of the first recess 31 .

[0308] The sealing plate 33 may be entirely located outside the first recess 31 , or may be partially accommodated in the first recess 31 , as long as the sealing plate 33 can close the opening of the first recess 31 .

[0309] The sealing plate 33 can protect the connecting portion 32 from the outside, reduce external impurities from entering the first recess 31 , reduce the risk of the connecting portion 32 being damaged by external impurities, and improve the sealing performance of the battery cell 7 .

[0310] In addition, the sealing plate 33 can also seal the first through hole 323. After the battery cell 7 is formed, the sealing plate 33 can reduce the risk of electrolyte leakage through the first through hole 323 and the first recess 31, thereby improving the sealing performance.

[0311] In some embodiments, a step surface 311 is provided on the side wall of the first recess 31 . At least a portion of the sealing plate 33 is accommodated in the first recess 31 , and the step surface 311 is used to support the sealing plate 33 .

[0312] The first recess 31 is a stepped recess that is larger on the outside and smaller on the inside.

[0313] When assembling the sealing plate 33, the stepped surface 311 supports and positions the sealing plate 33, thereby simplifying the assembly process. At least a portion of the sealing plate 33 is accommodated within the first recess 31, which reduces the overall size of the electrode terminal 30, reduces the space occupied by the electrode terminal 30, and improves energy density.

[0314] In some embodiments, the sealing plate 33 is welded to the sidewall of the first recess 31 to close the opening of the first recess 31 .

[0315] In some embodiments, a gap is provided between the sealing plate 33 and the connecting portion 32 , and the gap is used to avoid the first welding portion W1 .

[0316] The surface of the first welding portion W1 is uneven. If the sealing plate 33 presses against the first welding portion W1, it will cause the sealing plate 33 to wobble during assembly, affecting the sealing effect. In this embodiment, a gap is provided between the sealing plate 33 and the connecting portion 32 to avoid direct contact between the sealing plate 33 and the first welding portion W1, thereby reducing the shaking of the sealing plate 33 during assembly and ensuring the sealing effect.

[0317] In some examples, the first recess 31 has a stepped structure, so that the sealing plate 33 rests on the stepped surface 311 to form a gap between the sealing plate 33 and the connecting portion 32. In other examples, the connecting portion 32 may also be provided with a stepped structure, so that the sealing plate 33 can rest on the connecting portion 32, and the groove 324 on the connecting portion 32 forms a gap between the sealing plate 33 and the connecting portion 32.

[0318] In some embodiments, the sealing plate 33 can be welded to a busbar of the battery. In the battery, the busbar can connect the sealing plate 33 of one battery cell 7 and the cover 22 of another battery cell 7 to connect the two battery cells 7 in series.

[0319] In some embodiments, at least a portion of the sealing plate 33 protrudes from the second outer surface 344 of the terminal body 34 .

[0320] When the conduit component and the sealing plate 33 need to be welded, the conduit component is first attached to the upper surface of the sealing plate 33 (ie, the outer surface of the sealing plate 33 facing away from the connection portion 32 ), and then the conduit component and the sealing plate 33 are welded.

[0321] At least a portion of the sealing plate 33 protrudes from the second outer surface 344 to prevent the second outer surface 344 from interfering with the fit between the sealing plate 33 and the flow collecting component, thereby ensuring that the flow collecting component and the sealing plate 33 are tightly fitted.

[0322] In some embodiments, the connection portion 32 is disposed at one end of the terminal body 34 facing the electrode assembly 10 , and the first inner surface 321 of the connection portion 32 is flush with the second inner surface 345 .

[0323] The second inner surface 345 is the surface of the terminal body 34 that faces the electrode assembly 10. The first inner surface 321 of the connecting portion 32 constitutes a portion of the second inner surface 345. This allows the terminal body 34 to mate with the flat-plate current collecting member 40. In this embodiment, simply attaching the current collecting member 40 to the second inner surface 345 allows the connecting portion 32 and current collecting member 40 to mate, facilitating welding of the connecting portion 32 and current collecting member 40.

[0324] Figure 17 Schematic partial cross-sectional views of battery cells provided in some other embodiments of the present application.

[0325] like Figure 17 As shown, in some embodiments, the terminal body 34 has a second outer surface 344 and a second inner surface 345 disposed opposite to each other, and the first recess 31 is recessed from the second outer surface 344 in a direction facing the electrode assembly 10 to the first outer surface 322 of the connecting portion 32. The terminal body 34 further includes a third recess 35, which is recessed from the second inner surface 345 in a direction away from the electrode assembly 10 to the first inner surface 321 of the connecting portion 32.

[0326] The embodiment of the present application reduces the thickness of the connecting portion 32 by providing both the first recess 31 and the third recess 35. This reduces the depth requirement for the first recess 31 and simplifies the molding process. Providing the third recess 35 also increases the internal space of the battery cell 7, improving energy density.

[0327] In some embodiments, the current collecting component 40 includes a terminal connecting portion 46 and a tab connecting portion 47 surrounding the outside of the terminal connecting portion 46. The terminal connecting portion 46 is protruded relative to the tab connecting portion 47 and extends into the third recess 35 so that the top of the terminal connecting portion 46 abuts against the first inner surface 321 of the connecting portion 32.

[0328] The tab connection portion 47 is located between the cover 22 and the first tab 11 and is welded to the second portion 112 to form a third weld portion W3. Optionally, the tab connection portion 47 may be a circular flat plate structure.

[0329] In some embodiments, the current collecting member 40 is provided with a fourth recess 48 at a position corresponding to the terminal connecting portion 46. The fourth recess 48 is recessed relative to the surface of the tab connecting portion 47 facing the first tab 11. The fourth recess 48 can reduce the space occupied by the terminal connecting portion 46 and reduce the weight of the current collecting member 40. Exemplarily, the terminal connecting portion 46 and the fourth recess 48 are formed by stamping the current collecting member 40.

[0330] Figure 18 A partial cross-sectional schematic diagram of a battery cell provided in some other embodiments of the present application.

[0331] like Figure 18 As shown, in some embodiments, the terminal body 34 has a second outer surface 344 and a second inner surface 345 oppositely disposed, and the first recess 31 is recessed from the second inner surface 345 in a direction away from the electrode assembly 10 to the first inner surface 321 of the connecting portion 32 .

[0332] In this embodiment, the first recess 31 is positioned inside the terminal body 34 to ensure the flatness and area of ​​the second outer surface 344, facilitating connection between the terminal body 34 and an external current collector. Providing the first recess 31 inside the terminal body 34 also increases the internal space of the battery cell 7, thereby improving energy density.

[0333] In some embodiments, the current collecting component 40 includes a terminal connecting portion 46 and a tab connecting portion 47 surrounding the outside of the terminal connecting portion 46. The terminal connecting portion 46 is protruded relative to the tab connecting portion 47 and extends into the first recess 31 so that the top of the terminal connecting portion 46 abuts against the first inner surface 321 of the connecting portion 32.

[0334] The tab connection portion 47 is located between the cover 22 and the first tab 11 and is welded to the second portion 112 to form a third weld portion W3. Optionally, the tab connection portion 47 may be a circular flat plate structure.

[0335] In some embodiments, the current collecting member 40 is provided with a fourth recess 48 at a position corresponding to the terminal connecting portion 46. The fourth recess 48 is recessed relative to the surface of the tab connecting portion 47 facing the first tab 11. The fourth recess 48 can reduce the space occupied by the terminal connecting portion 46 and reduce the weight of the current collecting member 40. Exemplarily, the terminal connecting portion 46 and the fourth recess 48 are formed by stamping the current collecting member 40.

[0336] Figure 19 Schematic cross-sectional views of battery cells provided in some other embodiments of the present application.

[0337] like Figure 19 As shown, in some embodiments, the battery cell 7 may be a square battery cell.

[0338] In some embodiments, the housing 20 includes an integrally formed cylinder 21 and a cover 22, wherein the cylinder 21 is disposed around the periphery of the electrode assembly 10. For example, the cylinder 21 may be a square cylinder.

[0339] The cylinder 21 has an opening at one end facing away from the cover 22 , and the cover 50 covers the opening of the cylinder 21 to close the opening of the cylinder 21 . Exemplarily, the cover 50 is welded to the cylinder 21 .

[0340] 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 electrically connect to the first tab of the electrode assembly 10 , and the second electrode terminal 90 is used to electrically connect to the second tab of the electrode assembly 10 .

[0341] In some embodiments, the first electrode terminal 30 and the second electrode terminal 90 are both mounted on the cover 22 .

[0342] In a battery, a busbar connects the electrode terminals of multiple battery cells to connect the multiple battery cells in series, parallel, or in series. Both the first electrode terminal 30 and the second electrode terminal 90 can be used to connect to the busbar.

[0343] When the battery is subjected to an external impact, the current collector pulls on the cover 22 through the first electrode terminal 30 and the second electrode terminal 90, causing a force to act on the connection between the cover 22 and the barrel 21. If the cover 22 and the barrel 21 are separate structures, for example, the cover 22 and the barrel 21 are connected by welding, the connection between the cover 22 and the barrel 21 may fail under the action of force. In the embodiment of the present application, the cover 22 and the barrel 21 are integrally arranged, thereby improving the strength of the connection between the cover 22 and the barrel 21 and reducing the risk of connection failure between the cover 22 and the barrel 21.

[0344] In some embodiments, the housing 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, the housing 20 is not charged.

[0345] In some embodiments, the first tab and the second tab of the electrode assembly 10 are located on the same side of the electrode assembly facing the cover 22 .

[0346] According to some embodiments of the present application, a battery is further provided, comprising a plurality of battery cells according to any of the above embodiments.

[0347] According to some embodiments of the present application, there is also provided an electrical device comprising a battery according to any of the above embodiments, the battery being used to provide electrical energy to the electrical device. The electrical device may be any of the aforementioned devices or systems using battery cells.

[0348] Reference Figures 4 to 6 According to some embodiments of the present application, a cylindrical battery cell 7 is provided, including an electrode assembly 10 , a housing 20 , an electrode terminal 30 , a current collecting member 40 , and a cap plate 50 .

[0349] The housing 20 includes an integrally formed cylindrical body 21 and a cover 22. The cylindrical body 21 is disposed around the periphery of the electrode assembly 10. The cover 22 is provided with an electrode lead-out hole 221, into which the electrode terminal 30 is mounted. The cylindrical body 21 has an opening at one end facing away from the cover 22. The cover plate 50 covers the opening of the cylindrical body 21 to seal the opening.

[0350] The electrode assembly 10 includes a main body 12, a first electrode tab 11, and a second electrode tab 13. The first electrode tab 11 and the second electrode tab 13 protrude from the main body 12. The first electrode tab 11 is located at the end of the electrode assembly 10 facing the electrode terminal 30, and the second electrode tab 13 is located at the end of the electrode assembly 10 facing away from the electrode terminal 30.

[0351] The electrode terminal 30 includes a terminal body 34 and a sealing plate 33 . The terminal body 34 includes a first recess 31 and a connecting portion 32 located at the bottom of the first recess 31 . The sealing plate 33 is connected to the terminal body 34 and closes the opening of the first recess 31 .

[0352] The current collecting member 40 is welded to the first electrode tab 11 and the connecting portion 32 to electrically connect the first electrode tab 11 and the connecting portion 32 .

[0353] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0354] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell, characterized in that: include: An electrode assembly, comprising a first electrode tab, wherein the electrode assembly is a wound structure; a housing for accommodating the electrode assembly; an electrode terminal disposed in the housing, the electrode terminal comprising a first recess and a connecting portion located at a bottom of the first recess; and A current collecting component is connected to the first electrode tab and welded to the connecting portion, wherein the current collecting component is welded to the connecting portion and forms a first welding portion, and in the thickness direction of the connecting portion, the first welding portion extends from the side of the connecting portion away from the current collecting component to at least the interior of the current collecting component, in the thickness direction of the connecting portion, the first welding portion does not exceed the surface of the current collecting component away from the connecting portion, and the first welding portion is spaced a predetermined distance from the surface of the current collecting component away from the connecting portion, in the thickness direction of the connecting portion, the size of the first welding portion is h, and the thickness of the area of ​​the connecting portion for welding to the current collecting component is d0, and d0 and h satisfy: 1<h / d0≤1.

5.

2. The battery cell according to claim 1, wherein: The housing includes a cylinder and a cover connected to the cylinder, the cylinder is arranged around the outer circumference of the electrode assembly, the cover is provided with an electrode lead-out hole, and the electrode terminal is installed in the electrode lead-out hole; The first welding portion and the cover are both annular, the outer diameter of the cover is D0, and the inner diameter of the first welding portion is D1; D1 and D0 satisfy: 0.1≤D1 / D0≤0.

6.

3. The battery cell according to claim 2, characterized in that: The first welding portion is a non-closed structure, and the central angle of the first welding portion is 180°-330°.

4. The battery cell according to claim 2, characterized in that: The first welding portion is a closed structure.

5. The battery cell according to claim 2, characterized in that: 0.2≤D1 / D0≤0.

4.

6. The battery cell according to claim 2, characterized in that D1 is 5mm-14mm.

7. The battery cell according to claim 2, characterized in that: The cover body and the cylinder body are formed as an integral structure.

8. The battery cell according to any one of claims 1 to 7, characterized in that: A thickness of a region of the current collecting member for welding to the connecting portion is d1, and d0 and d1 satisfy the following: 0.5≤d1 / d0≤1.

2.

9. The battery cell according to claim 8, characterized in that d0 is 0.4mm-1.2mm.

10. The battery cell according to any one of claims 1 to 7, characterized in that: At least a portion of the first electrode tab is located on a side of the current collecting member facing away from the electrode terminal and is supported by the current collecting member.

11. The battery cell according to claim 10, characterized in that The first portion of the first electrode tab is located on a side of the connecting portion away from the first recess and is used to support a portion of the current collecting member opposite to the connecting portion.

12. The battery cell according to claim 11, characterized in that The first portion is welded to the current collecting member to form a second weld portion.

13. The battery cell according to claim 11, characterized in that The second portion of the first electrode tab surrounds the outer circumference of the first portion and is used to support the area of ​​the current collecting member that is not opposite to the connecting portion.

14. The battery cell according to claim 13, characterized in that The second portion is welded to the current collecting member to form a third welding portion.

15. The battery cell according to claim 14, characterized in that The current collecting member has a protrusion on a side facing the first electrode tab, and the protrusion is welded to the second portion to form the third weld portion.

16. The battery cell according to claim 14, characterized in that The first electrode tab is arranged around the central axis of the electrode assembly, and a cross section of the first electrode tab perpendicular to the central axis is annular; The outer radius of the first tab is R, and the minimum distance between the third welding portion and the central axis in the radial direction of the first tab is D2, and both satisfy: 0.2≤D2 / R≤0.

8.

17. The battery cell according to claim 16, characterized in that D2 and R satisfy: 0.2≤D2 / R≤0.

5.

18. The battery cell according to claim 16, characterized in that D2 is 3.5mm-10mm.

19. The battery cell according to claim 10, characterized in that The diameter of the current collecting component is D3, the diameter of the first electrode tab is D4, and D3 is smaller than D4.

20. The battery cell according to claim 19, characterized in that D3 and D4 satisfy: 0.75≤D3 / D4≤0.

97.

21. The battery cell according to claim 19, characterized in that D3 is 35mm-44mm.

22. The battery cell according to any one of claims 1 to 7, characterized in that: The connecting portion is provided with a groove recessed from a first outer surface of the connecting portion in a direction facing the electrode assembly, and the first welding portion extends from a bottom wall of the groove at least to an interior of the current collecting member.

23. The battery cell according to any one of claims 1 to 7, characterized in that: The housing includes a cylinder and a cover connected to the cylinder, the cylinder is arranged around the outer circumference of the electrode assembly, the cover is provided with an electrode lead-out hole, and the electrode terminal is installed in the electrode lead-out hole; The electrode terminal includes a terminal body, which includes a columnar portion, a first limiting portion and a second limiting portion. At least a portion of the columnar portion is located in the electrode lead-out hole. The first recess is provided in the columnar portion. The first limiting portion and the second limiting portion are both connected to and protrude from the outer side wall of the columnar portion. The first limiting portion and the second limiting portion are respectively provided on the outer side and the inner side of the cover body and are used to clamp a portion of the cover body.

24. The battery cell according to claim 23, characterized in that The terminal body has a second outer surface, and the first recess is recessed from the second outer surface in a direction facing the electrode assembly to the first outer surface of the connecting portion.

25. The battery cell according to claim 23, characterized in that The electrode terminal further includes a sealing plate connected to the terminal body and closing an opening of the first recess.

26. The battery cell according to any one of claims 1 to 7, characterized in that: The electrode assembly further includes a second electrode tab having a polarity opposite to that of the first electrode tab, the second electrode tab being arranged around the central axis of the electrode assembly; The first electrode tab is provided at one end of the electrode assembly facing the electrode terminal, the second electrode tab is provided at one end of the electrode assembly facing away from the electrode terminal, and the second electrode tab is electrically connected to the shell.

27. The battery cell according to claim 26, characterized in that The second electrode tab is a negative electrode tab, and the base material of the shell is steel.

28. The battery cell according to any one of claims 1 to 7, characterized in that: The housing has an opening at one end away from the electrode terminal, and the battery cell further includes a cover plate for closing the opening.

29. A battery, characterized in that: The invention comprises a plurality of battery cells according to any one of claims 1 to 28.

30. An electrical device, characterized in that: The battery of claim 29 is included for providing electrical energy.

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