Battery cell and battery

Abstract

A battery cell and a battery, relating to the technical field of batteries. The battery cell comprises a casing, an electrode assembly, and a pole; the casing forms an accommodating cavity; the electrode assembly is arranged in the accommodating cavity, and the electrode assembly comprises a core, and a first tab and a second tab which are respectively arranged at two ends of the core; the pole is connected to the casing and insulated from the casing; the first tab comprises a first negative electrode region and a second negative electrode region, the first negative electrode region is electrically connected to the casing, and the second negative electrode region is stacked with a negative electrode end surface of the core; and the second tab comprises a first positive electrode region and a second positive electrode region, the first positive electrode region is electrically connected to the pole, and the second positive electrode region is stacked with a positive electrode end surface of the core.

Description

Battery cells and batteries

[0001] Cross-references to related applications

[0002] This application is based on and claims priority to Chinese Patent Application No. 202520006533.4, filed on January 2, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of batteries, and more specifically, to a battery cell, a battery, and an electrical device. Background Technology

[0004] In related technologies, electrical connections within battery cells are often achieved through-welding. However, due to factors such as the flatness and surface cleanliness of the object being welded, safety issues such as incomplete welding or burn-through can occur, resulting in poor reliability of electrical connections within battery cells. Therefore, improvements are needed. Summary of the Invention

[0005] This application provides a battery cell, a battery, and an electrical device to improve the reliability of electrical connections within the battery cell.

[0006] In a first aspect, embodiments of this application provide a single battery cell, comprising:

[0007] The outer shell forms a receiving cavity;

[0008] An electrode assembly is disposed within the receiving cavity, the electrode assembly comprising a battery cell and a first electrode tab and a second electrode tab disposed at both ends of the battery cell;

[0009] The pole is connected to and insulated from the outer casing;

[0010] The first electrode includes a first negative electrode region and a second negative electrode region. The first negative electrode region is electrically connected to the outer casing, and the second negative electrode region is stacked on the negative terminal face of the battery cell. The second electrode includes a first positive electrode region and a second positive electrode region. The first positive electrode region is electrically connected to the electrode post, and the second positive electrode region is stacked on the positive terminal face of the battery cell.

[0011] In the above technical solution, by setting both the positive and negative electrode tabs to have flattened and non-flattened areas, the non-flattened area of ​​the positive electrode tab is connected to the terminal post, and the non-flattened area of ​​the negative electrode tab is connected to the outer shell. The negative terminal can omit the current collector such as the terminal post and the adapter plate, thereby simplifying multiple welding steps and reducing the risk of adverse effects caused by welding. The positive terminal can reduce the influence of factors such as the flatness and surface cleanliness of the welding object on the welding effect, improve the welding effect, and thus improve the reliability and safety of the battery cell electrical connection.

[0012] Secondly, embodiments of this application provide a battery comprising: a plurality of battery cells as described in any of the embodiments above.

[0013] Thirdly, embodiments of this application provide an electrical device, including: a battery as described in any of the above embodiments, the battery being used to provide electrical energy to the electrical device. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application;

[0016] Figure 2 is an exploded view of the battery structure provided in some embodiments of this application;

[0017] Figure 3 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0018] Figure 4 is a second schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0019] Figure 5 is a third schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0020] Figure 6 is a fourth schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0021] Figure 7 is a fifth schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0022] Figure 8 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0023] Figure 9 is a seventh schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0024] Figure 10 is the eighth of the structural schematic diagrams of a battery cell provided in some embodiments of this application;

[0025] Figure 11 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0026] Figure 12 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0027] Figure 13 is an eleventh schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0028] Figure 14 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application, number 12.

[0029] Figure 15 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application, number thirteen.

[0030] Figure 16 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application, number fourteen.

[0031] Figure 17 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application, number fifteen.

[0032] Figure 18 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0033] Figure 19 is the seventeenth schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0034] Figure 20 is an eighteenth schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0035] Figure 21 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0036] Figure 22 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0037] Figure 23 is one of the structural schematic diagrams of the battery cell provided in some embodiments of this application;

[0038] Figure 24 is a second schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0039] Figure 25 is a third schematic diagram of the structure of a battery cell provided in some embodiments of this application.

[0040] Reference numerals: Vehicle 1, Battery 10, Box 11, First Box Body 111, Second Box Body 112; Battery Cell 12, Shell 121, Receiving Cavity 1211, First Part 1212, Second Part 1213, Negative Electrode Annular Groove 12131, Positive Electrode Annular Groove 12132, Negative Electrode End Wall 1214, Flanged Edge 1215; Electrode Assembly 122, Cell 1221, Negative Electrode Surface 12211, Positive Electrode Surface 12212, First Tab 1222, Negative Electrode First Region 12221, Negative Electrode Second Region 12222, Second Tab 1223, Positive Electrode First Region 12231, Positive Electrode Second Region 12232, Tab Connector 1224; Terminal 123, Terminal Body 1231, Adapter 1232, First Connector 12321, Second Connector 12322, Mounting Ring Groove 12323; Sealed insulation component 124, bent section 1241; negative end cover 125; motor 20, controller 30, welding head 40. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0042] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0043] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0044] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0045] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0046] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0047] The battery cells mentioned in the embodiments of this application 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 this application are not limited to these. Battery cells may be cylindrical, flat, cuboid, or other shapes, and the embodiments of this application are not limited to these shapes either. Battery cells are generally classified into three types according to their packaging method: cylindrical battery cells, square battery cells, and pouch battery cells; the embodiments of this application use cylindrical battery cells.

[0048] The battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in this application may include a battery module or a battery pack. A battery generally includes a housing for encapsulating one or more battery cells or multiple battery modules. The housing can prevent liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0049] A battery cell includes a casing, electrode assembly, and electrolyte. The casing houses the electrode assembly and electrolyte. The electrode assembly consists of a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrodes. The positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector, and the uncoated positive current collector protrudes beyond the coated positive current collector, serving as the second tab. Taking a lithium-ion battery as an example, the positive current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector, and the uncoated negative current collector protrudes beyond the coated negative current collector, serving as the first tab. The negative electrode current collector can be made of copper, and the negative electrode active material can be carbon or silicon, etc. To ensure that a large current can be passed without melting, there are multiple second tabs stacked together, and there are multiple first tabs stacked together.

[0050] The separator can be made of PP (polypropylene) or PE (polyethylene), etc. Furthermore, the electrode assembly can be a wound structure or a stacked structure; the embodiments of this application are not limited to these.

[0051] With the gradual popularization of new energy technologies, lithium battery technology has continued to develop. Lithium batteries are favored by the new energy industry because of their excellent characteristics such as large energy storage capacity, stable power supply capacity, and long service life.

[0052] A battery consists of a casing and multiple individual battery cells housed within it. As a core component of new energy vehicles, the battery faces stringent requirements in terms of both safety and cycle life.

[0053] The inventors discovered that in typical battery cells, the electrical connections between the tabs, adapters, and terminals within the battery cell are mostly achieved through-welding. Due to factors such as the flatness and surface cleanliness of the welded object, safety issues such as incomplete welding or burn-through occur, resulting in poor reliability of the electrical connections within the battery cell. Therefore, improvements are needed.

[0054] Based on the above considerations, in order to solve the problem of poor electrical connection reliability within a single battery cell, the inventors, after in-depth research, designed a battery cell including a casing, an electrode assembly, and terminals; the casing forms a receiving cavity; the electrode assembly is disposed within the receiving cavity, and the electrode assembly includes a cell and a first electrode tab and a second electrode tab disposed at both ends of the cell; the terminals are connected to the casing and insulated from it; wherein, the first electrode tab includes a first negative electrode region and a second negative electrode region, the first negative electrode region is electrically connected to the casing, and the second negative electrode region is stacked with the negative terminal face of the cell; the second electrode tab includes a first positive electrode region and a second positive electrode region, the first positive electrode region is electrically connected to the terminals, and the second positive electrode region is stacked with the positive terminal face of the cell.

[0055] In this type of battery cell, by setting both the positive and negative electrode tabs to have flattened and non-flattened areas, the non-flattened area of ​​the positive electrode tab is connected to the terminal post, and the non-flattened area of ​​the negative electrode tab is connected to the outer casing. The negative terminal can omit current collectors such as terminals and adapter plates, thereby simplifying multiple welding steps and reducing the risk of adverse effects caused by welding. The positive terminal can reduce the influence of factors such as the flatness and surface cleanliness of the welding object on the welding effect, improve the welding effect, and thus improve the reliability and safety of the battery cell electrical connection.

[0056] The batteries disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power system for such an electrical device can be constructed using battery cells and batteries disclosed in this application, which helps to improve the reliability of the battery cells.

[0057] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, and spacecraft. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft.

[0058] For ease of explanation, the following embodiments will be described using a vehicle as an example of an electrical device according to an embodiment of this application.

[0059] As shown in Figure 1, which is a structural schematic diagram of a vehicle 1 according to an embodiment of this application, the vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. The vehicle 1 can have a motor 20, a controller 30, and a battery 10 installed inside. The controller 30 controls the battery 10 to supply power to the motor 20. For example, the battery 10 can be installed at the bottom, front, or rear of the vehicle 1. The battery 10 can be used to power the vehicle 1; for example, the battery 10 can serve as the operating power source for the vehicle 1's electrical system, such as meeting the power requirements for starting, navigation, and operation of the vehicle 1.

[0060] In another embodiment of this application, the battery 10 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0061] To meet different power needs, the battery 10 may include multiple battery cells 12, which may be connected in series, in parallel, or in a mixed manner. Mixed connection refers to a combination of series and parallel connections.

[0062] Figure 2 shows an exploded view of the structure of a battery 10 according to an embodiment of this application. The battery 10 includes a housing 11 and a plurality of battery cells 12, which are housed within the housing 11. The housing 11 provides assembly space for the battery cells 12, and the housing 11 can adopt various structures. In some embodiments, the housing 11 may include a first housing body 111 and a second housing body 112, which cover each other, and together define an assembly space for accommodating the battery cells 12. The second housing body 112 may be a hollow structure open at one end, and the first housing body 111 may be a plate-like structure, with the first housing body 111 covering the open side of the second housing body 112, so that the first housing body 111 and the second housing body 112 together define the assembly space; the first housing body 111 and the second housing body 112 may also be hollow structures both open on one side, with the open side of the first housing body 111 covering the open side of the second housing body 112. Of course, the box 11 formed by the first box body 111 and the second box body 112 can be of various shapes, such as a cylinder or a cuboid.

[0063] In battery 10, multiple battery cells 12 can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 12 are connected in both series and parallel. Multiple battery cells 12 can be directly connected in series, parallel, or in a mixed manner, and then the whole assembly of multiple battery cells 12 is housed in housing 11. Of course, battery 10 can also be composed of multiple battery cells 12 first connected in series, parallel, or in a mixed manner to form battery 10 modules, and then multiple battery 10 modules are connected in series, parallel, or in a mixed manner to form a whole assembly, which is housed in housing 11.

[0064] A battery cell 12 refers to the smallest unit that makes up a battery 10. A battery cell 12 includes a casing, a cell, and an electrolyte, with the casing used to house the cell and the electrolyte.

[0065] The casing includes a top cover assembly and a housing. The top cover assembly is the component that closes onto the opening of the housing to separate the internal environment of the battery cell from the external environment.

[0066] The top cover assembly includes a top cover and a filter screen. The top cover has an injection hole for injecting electrolyte. The filter screen is installed on the top cover and covers the injection hole. The filter screen is used to filter the injected electrolyte.

[0067] The shape of the top cover can be adapted to the shape of the housing to fit the housing. Optionally, the top cover can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the top cover is not easily deformed when subjected to compression and impact, allowing the battery cell to have higher structural strength and improved reliability. Functional components such as electrode terminals can be provided on the top cover. The electrode terminals can be used to electrically connect with the battery cell for outputting or inputting electrical energy to the battery cell. In some embodiments, the top cover can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the battery cell reaches a threshold. The material of the top cover can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this. In some embodiments, an insulating component can also be provided on the inner side of the top cover. The insulating component can be used to isolate the electrical connection components inside the housing from the top cover to reduce the risk of short circuit. For example, the insulating component can be plastic, rubber, etc.

[0068] The housing is a component used to fit the top cover to form the internal environment of a battery cell, wherein the formed internal environment can be used to house the cell, electrolyte, and other components.

[0069] The casing and top cover can be independent components. An opening can be provided on the casing, and the top cover closes the opening to form the internal environment of the battery cell. Alternatively, the top cover and casing can be integrated. Specifically, the top cover and casing can form a common connecting surface before other components are inserted into the casing. When it is necessary to encapsulate the interior of the casing, the top cover closes the casing. The casing can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the casing can be determined according to the specific shape and size of the battery cell. The casing material can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. This application does not impose any special limitations on this.

[0070] The battery comprises multiple rows of battery cells arranged along a first direction, and each row of battery cells includes multiple battery cells arranged along a second direction. The first direction and the second direction are the length direction and the width direction of the housing, respectively, and are perpendicular to each other.

[0071] Each battery cell can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell can be cylindrical, flat, cuboid, or other shapes. For example, the battery cell is cylindrical.

[0072] According to some embodiments of this application, as shown in Figures 8, 14 and 22, this application provides a battery cell 12, including: a housing 121, an electrode assembly 122 and a terminal post 123.

[0073] The outer casing 121 forms a receiving cavity 1211, which is used to receive the electrode assembly 122.

[0074] The electrode assembly 122 is disposed in the receiving cavity 1211. The electrode assembly 122 includes a battery cell 1221 and a first tab 1222 and a second tab 1223 disposed at both ends of the battery cell 1221.

[0075] One of the first tab 1222 and the second tab 1223 is a negative tab, and the other of the first tab 1222 and the second tab 1223 is a positive tab. The negative tab and the positive tab are respectively located at both ends of the battery cell 1221 to reduce the possibility of short circuit between the first tab 1222 and the second tab 1223.

[0076] The terminal 123 is connected to and insulated from the housing 121. The terminal 123 can be connected to the housing 121 by plugging or soldering. The terminal 123 and the housing 121 are isolated by an insulating material, such as ceramic, plastic, or rubber, to prevent short circuits between the terminal 123 and the housing 121. One of the terminals 123 and the housing 121 is the negative terminal, and the other of the terminals 123 and the housing 121 is also the negative terminal.

[0077] In this embodiment, the first electrode 1222 can be a negative electrode, and the second electrode 1223 is a positive electrode. The positive electrode is electrically connected to the external circuit through the electrode post 123, and the negative electrode is electrically connected to the external circuit through the outer casing 121.

[0078] As shown in Figure 4, the first electrode tab 1222 includes a negative electrode first region 12221 and a negative electrode second region 12222. The negative electrode first region 12221 can be the non-flattened region of the negative electrode tab, and the negative electrode second region 12222 is the flattened region of the negative electrode tab. The negative electrode first region 12221 is electrically connected to the outer shell 121, and the negative electrode second region 12222 is stacked with the negative terminal face 12211 of the battery cell 1221. The negative electrode second region 12222 is electrically connected to the battery cell 1221 by flattening.

[0079] As shown in Figures 23 and 25, before the cell 1221 is assembled with the outer casing 121, the tab connection 1224 of the negative electrode first region 12221 can be in an upright state; as shown in Figure 3, before the cell 1221 is assembled with the outer casing 121 but the opening of the outer casing 121 is not sealed, the tab connection 1224 of the negative electrode first region 12221 and the outer casing 121 have overlapping areas along the radial direction of the battery cell 12, and the tab connection 1224 of the negative electrode first region 12221 can be connected to the outer casing 121 by side welding along the radial direction.

[0080] For example, as shown in FIG3, the tab connection portion 1224 of the negative electrode first region 12221 can be electrically connected to the outer shell 121 by welding methods such as ultrasonic roll welding or laser side welding.

[0081] Understandably, due to the thin foil thickness at the edge of the tab, the edge of the tab may be uneven, potentially resulting in burrs and flanges. Therefore, during welding of the tab to the current collector, some areas at the edge of the tab may not make proper contact with the end of the cell, leading to unstable welding area. Smoothing or flattening the tab can increase its flatness, improve the welding effect between the flattened area of ​​the tab and the cell, and optimize the electrical connection between the flattened area of ​​the tab and the cell.

[0082] In this embodiment, by stacking the negative electrode second region 12222 with the negative end face 12211 of the battery cell 1221, the negative electrode second region 12222 is electrically connected to the battery cell 1221 by flattening, thus optimizing the electrical connection between the negative electrode second region 12222 and the battery cell 1221, as well as between adjacent coil tab connection portions 1224 within the negative electrode second region 12222.

[0083] For example, the tabs can be flattened by mechanical flattening or smoothing, and the tabs in the negative electrode second region 12222 at the end of the cell 1221 can be flattened into a plane, so that the tabs of adjacent layers are in close contact and the welding effect is improved.

[0084] In this embodiment, by dividing the negative electrode tab into a first negative electrode region 12221 and a second negative electrode region 12222, the first negative electrode region 12221 can be directly electrically connected to the casing by side welding, omitting current collectors such as the terminal post 123 and the adapter piece, thereby simplifying multiple welding steps, reducing the risk of adverse effects caused by welding, and improving the reliability of electrical connections within the battery cell 12; the second negative electrode region 12222 is flattened and stacked with the negative end face 12211 of the cell 1221, optimizing the electrical connection between the second negative electrode region 12222 and the cell 1221, as well as between adjacent tabs within the second negative electrode region 12222, thereby further improving the reliability of electrical connections within the battery cell 12.

[0085] The relative positional relationship between the negative electrode second region 12222 and the negative electrode first region 12221 can be determined based on the arrangement position of the first electrode tab 1222 and the second electrode tab 1223 in the cell 1221 and the shape of the casing.

[0086] For example, as shown in Figures 23 and 25, when the first tab 1222 and the second tab 1223 are respectively disposed at both ends of the cell 1221, the negative electrode second region 12222 can be located in the inner ring relative to the negative electrode first region 12221, so that the negative electrode second region 12222 located in the outer ring can be welded to the outer casing 121; or, the negative electrode second region 12222 and the negative electrode first region 12221 can be distributed relative to each other with the axis of the battery cell 12 as the center of symmetry.

[0087] The second electrode 1223 includes a positive first region 12231 and a positive second region 12232. The positive first region 12231 is electrically connected to the electrode post 123. The relative positional relationship between the positive second region 12232 and the positive first region 12231 can be determined according to the arrangement position of the first electrode 1222 and the second electrode 1223 in the cell 1221 and the shape of the casing.

[0088] The first positive electrode region 12231 can be the non-flattened region of the positive electrode tab, and the second positive electrode region 12232 is the flattened region of the positive electrode tab. The first positive electrode region 12231 is electrically connected to the electrode post 123, and the second positive electrode region 12232 is stacked with the positive terminal face 12212 of the battery cell 1221. The second positive electrode region 12232 is electrically connected to the battery cell 1221 by flattening.

[0089] As shown in Figures 23 and 25, before the cell 1221 is assembled with the casing 121, the tab connection 1224 of the positive electrode first region 12231 can be in an upright state; after the cell 1221 is placed inside the casing 121 and assembled with the terminal post 123, the tab connection 1224 of the positive electrode first region 12231 and the side of the terminal post 123 have overlapping areas along the radial direction of the battery cell 12, and the tab connection 1224 of the positive electrode first region 12231 and the side of the terminal post 123 can be connected by side welding in the radial direction.

[0090] In this embodiment, the positive electrode tab is divided into a first positive electrode region 12231 and a second positive electrode region 12232. The first positive electrode region 12231 can be electrically connected to the electrode post 123 by side welding. During the electrical connection process, the influence of factors such as the flatness and surface cleanliness of the welding object on the welding effect can be reduced, thereby improving the reliability of the electrical connection within the battery cell 12. The second positive electrode region 12232 is stacked with the positive end face 12212 of the cell 1221 after being flattened. This optimizes the electrical connection between the second positive electrode region 12232 and the cell 1221, as well as between adjacent electrode tabs within the second positive electrode region 12232, thereby further improving the reliability of the electrical connection within the battery cell 12.

[0091] For example, as shown in FIG6, when the first tab 1222 and the second tab 1223 are respectively disposed at both ends of the cell 1221, the positive electrode second region 12232 can be located in the inner ring relative to the positive electrode first region 12231, so that the positive electrode second region 12232 located in the outer ring can be welded to the electrode post 123; or, the positive electrode second region 12232 and the positive electrode first region 12231 can be distributed relative to each other with the axis of the battery cell 12 as the center of symmetry.

[0092] The negative electrode first region 12221 can be a multi-turn tab connection part arranged radially along the battery cell. The positive electrode first region 12231 can be a multi-turn tab connection part arranged radially along the battery cell.

[0093] In related technologies, electrical connections within battery cells are mostly achieved through welding. In particular, cylindrical battery cells require the tabs to be flattened to achieve electrical welding connections with the adapter plates. Due to factors such as the flatness and surface cleanliness of the welding object, the welding gap between the adapter plate and the flattened tab layer can easily lead to weld penetration and burning of the separator, resulting in poor safety and welding efficiency.

[0094] The battery cell 12 provided in this application embodiment has a structure with both positive and negative electrode tabs having flattened and non-flattened areas. The non-flattened area of ​​the positive electrode tab is connected to the terminal post 123, and the non-flattened area of ​​the negative electrode tab is connected to the outer casing 121. The negative terminal can omit the terminal post 123 and the current collector such as the adapter plate, thereby simplifying multiple welding steps and reducing the risk of adverse effects caused by welding. The positive terminal can reduce the influence of factors such as the flatness and surface cleanliness of the welding object on the welding effect, improve the welding effect, and thus improve the reliability and safety of the electrical connection of the battery cell 12.

[0095] According to some embodiments of this application, as shown in Figures 4 and 6, the negative electrode second region 12222 is located in the inner circle relative to the negative electrode first region 12221, and the positive electrode second region 12232 is located in the inner circle relative to the positive electrode first region 12231.

[0096] The relative positional relationship between the positive electrode second region 12232 and the positive electrode first region 12231 can be determined based on the arrangement position of the first electrode tab 1222 and the second electrode tab 1223 in the cell 1221 and the shape of the casing; the relative positional relationship between the negative electrode second region 12222 and the negative electrode first region 12221 can be determined based on the arrangement position of the first electrode tab 1222 and the second electrode tab 1223 in the cell 1221 and the shape of the casing.

[0097] In this embodiment, with the first tab 1222 and the second tab 1223 respectively located at both ends of the battery cell 1221, the positive electrode second region 12232 can be located in the inner ring relative to the positive electrode first region 12231, so that the positive electrode second region 12232 located in the outer ring can be welded to the electrode post 123; the negative electrode second region 12222 can be located in the inner ring relative to the negative electrode first region 12221, so that the negative electrode second region 12222 located in the outer ring can be welded to the outer casing 121.

[0098] According to some embodiments of this application, the negative electrode second region 12222 is located in the inner ring relative to the negative electrode first region 12221, so that the negative electrode second region 12222 located in the outer ring is welded to the outer casing 121.

[0099] According to some embodiments of this application, the positive electrode second region 12232 is located in the inner ring relative to the positive electrode first region 12231, so that the positive electrode second region 12232 located in the outer ring is welded to the electrode post 123.

[0100] In this embodiment, the negative electrode second region 12222 can be a tab structure with a portion of its height removed or not removed. The negative electrode second region 12222 is flattened or smoothed to ensure better contact with the end of the battery cell 1221. The positive electrode second region 12232 can be a tab structure with a portion of its height removed or not removed. The positive electrode second region 12232 is flattened or smoothed to ensure better contact with the end of the battery cell 1221.

[0101] According to some embodiments of this application, as shown in Figures 23 and 24, the negative electrode first region 12221 is continuously arranged around the axis of the battery cell 12, and the positive electrode first region 12231 is continuously arranged around the axis of the battery cell 12.

[0102] In this embodiment, the battery cell 1221 can be a wound type, and the tab connection portion 1224 of the negative electrode first region 12221 and the positive electrode first region 12231 can both be continuous structures without die cutting. The tab connection portion 1224 of the negative electrode first region 12221 and the positive electrode first region 12231 can be provided with one or more turns along the winding direction.

[0103] In this embodiment, by setting continuous negative electrode first region 12221 and positive electrode first region 12231, the negative electrode first region 12221 is connected to the inner wall of the outer casing 121 by side welding or pressing, and the positive electrode first region 12231 is electrically connected to the side wall of the electrode post 123 by side welding or pressing. This can improve the uniformity and reliability of the electrical connection between the negative electrode first region 12221 and the outer casing 121, and between the positive electrode first region 12231 and the side wall of the electrode post 123, thereby improving the reliability of the battery cell 12.

[0104] According to some embodiments of this application, the negative electrode first region 12221 is continuously arranged around the axis of the battery cell 12. The negative electrode first region 12221 is electrically connected to the inner wall of the outer casing 121 by side welding or pressing. This can improve the uniformity and reliability of the electrical connection between the negative electrode first region 12221 and the outer casing 121, thereby improving the reliability of the battery cell 12.

[0105] According to some embodiments of this application, the positive electrode first region 12231 is continuously arranged around the axis of the battery cell 12. The positive electrode first region 12231 is electrically connected to the side wall of the electrode post 123 by side welding or pressing. This can improve the uniformity and reliability of the electrical connection between the positive electrode first region 12231 and the side wall of the electrode post 123, thereby improving the reliability of the battery cell 12.

[0106] According to some embodiments of this application, both the positive electrode first region 12231 and the negative electrode first region 12221 include a plurality of electrode tabs 1224, which are spaced apart.

[0107] In this embodiment, a notch is provided between two adjacent tabs 1224 in the same loop of the multiple tabs 1224 in the positive electrode first region 12231 and the negative electrode first region 12221. When the multiple loops of tabs 1224 in the negative electrode first region 12221 are stacked, the thickness of the stacked negative electrode first region 12221 can be reduced. When the multiple loops of tabs 1224 in the positive electrode first region 12231 are stacked, the thickness of the stacked positive electrode first region 12231 can be reduced. When the positive electrode first region 12231 and the negative electrode first region 12221 are stacked in their respective positions, the axial height of the cell 1221 can be reduced, and the weight of the battery cell 12 can be reduced.

[0108] According to some embodiments of this application, as shown in FIG25, the positive electrode first region 12231 includes a plurality of tab connection portions 1224, which are spaced apart. When multiple loops of tab connection portions 1224 are stacked in the negative electrode first region 12221, the thickness of the stacked negative electrode first region 12221 can be reduced. When the negative electrode first region 12221 is stacked relative to the negative electrode second region 12222, the axial height of the cell 1221 can be reduced, and the weight of the battery cell 12 can be reduced.

[0109] According to some embodiments of this application, the negative electrode first region 12221 includes a plurality of tab connection portions 1224, which are spaced apart. When multiple loops of tab connection portions 1224 are stacked in the positive electrode first region 12231, the thickness of the stacked positive electrode first region 12231 can be reduced. When the positive electrode first region 12231 is stacked relative to the positive electrode second region 12232, the axial height of the cell 1221 can be reduced, and the weight of the battery cell 12 can be reduced.

[0110] According to some embodiments of this application, a plurality of electrode connectors 1224 are arranged in multiple rings, and the plurality of electrode connectors 1224 in the same ring are spaced apart circumferentially. For example, the plurality of electrode connectors 1224 in the same ring can be evenly spaced apart circumferentially.

[0111] At least some of the tab connections 1224 in two adjacent rings are arranged radially staggered, and some of the tab connections 1224 in the previous ring are located above or below the gap between adjacent tab connections 1224 in the next ring.

[0112] In other words, the radial projection of the multiple tab connection portions 1224 in the negative electrode first region 12221 is a continuous structure, and the radial projection of the negative electrode first region 12221 does not have any gaps. This facilitates the continuity of welding between the negative electrode first region 12221 and the outer shell 121, reduces the welding difficulty, and improves the uniformity and reliability of the electrical connection between the negative electrode first region 12221 and the outer shell 121.

[0113] The radial projection of the multiple tab connection portions 1224 in the positive electrode first region 12231 is a continuous structure. The radial projection of the positive electrode first region 12231 does not have any gaps, which facilitates the continuity of welding between the positive electrode first region 12231 and the side wall of the electrode post 123, reduces the welding difficulty, and improves the uniformity and reliability of the electrical connection between the positive electrode first region 12231 and the side wall of the electrode post 123.

[0114] According to some embodiments of this application, as shown in FIG8, the electrode post 123 includes an electrode post body 1231 and an adapter 1232. The adapter 1232 is installed on the housing 121, and the electrode post body 1231 is electrically connected to the positive electrode first region 12231 through the adapter 1232.

[0115] Both the adapter 1232 and the electrode body 1231 are insulated from the outer casing 121. The positive electrode first zone 12231 and the adapter 1232 can be electrically connected by welding to achieve effective current transfer. The adapter 1232 and the electrode body 1231 can be electrically connected by welding, snap-fitting or threaded connection.

[0116] The terminal body 1231 is located at the end of the adapter 1232 away from the cell 1221. The terminal body 1231 can act as a positive terminal cap to close the positive terminal opening of the outer casing 121. That is, the terminal body 1231 is spaced apart from the cell 1221 to reserve an explosion-proof gap inside the battery cell 12, thereby improving the reliability and safety of the battery cell 12.

[0117] In some embodiments, after the battery cell 12 is filled with electrolyte, the terminal body 1231 is placed on the adapter 1232 to close the opening of the adapter ring.

[0118] The adapter 1232 can be a ring-shaped hollow structure. The outer wall of the adapter 1232 is sealed and insulated from the outer shell 121. The battery cell 12 can be injected with liquid through the hollow structure of the adapter 1232. After the liquid injection is completed, the electrode body 1231 can be placed on the hollow structure of the adapter 1232 to seal the adapter 1232.

[0119] The electrode body 1231 can be used as the positive electrode of the battery cell 12. The adapter 1232 acts as an electrical connection bridge, allowing the current in the first region 12231 of the positive electrode to be smoothly transmitted to the electrode body 1231 through the adapter 1232. The adapter 1232 can be made of conductive material and needs to have good conductivity and mechanical strength.

[0120] According to some embodiments of this application, as shown in FIG8, the positive electrode first region 12231 is connected to at least two walls of the adapter 1232, thereby improving the uniformity and stability of current transmission between the positive electrode first region 12231 and the adapter 1232, thereby improving the overall performance of the battery assembly, while reducing the axial height of the battery cell 12.

[0121] For example, during assembly, the bottom surface of the adapter 1232 along the axial direction of the battery cell 12 can be pressed onto the positive electrode first region 12231. After the adapter 1232 is installed and fixed, a portion of the tab connection portion 1224 of the positive electrode first region 12231 can be bent so that the bent portion of the tab connection portion 1224 overlaps with the side wall of the adapter 1232 in the radial direction, so that the bent portion of the tab connection portion 1224 can be side-welded to the side wall of the adapter 1232. In other words, the positive electrode first region 12231 can be connected to the bottom surface of the adapter 1232 along the axial direction of the battery cell 12 and the side wall of the adapter 1232.

[0122] For example, the bent portion of the tab connection portion 1224 of the positive electrode first region 12231 can be electrically connected to the side wall of the adapter 1232 by welding methods such as ultrasonic roll welding or laser side welding.

[0123] The positive terminal of the battery cell 12 has at least the following two structures.

[0124] Firstly, as shown in Figure 8, the outer casing 121 has a positive electrode annular groove 12132 on the part of the positive electrode protruding from the cell 1221; the adapter 1232 includes a first connecting part 12321 and a second connecting part 12322 connected together. The first connecting part 12321 can extend radially along the battery cell 12 and be assembled with the positive electrode annular groove 12132.

[0125] The first connecting part 12321 and the second connecting part 12322 can be integrally formed or welded together.

[0126] For example, the first connecting portion 12321 and the second connecting portion 12322 can be bent relative to each other, and the second connecting portion 12322 can extend along the axial direction of the battery cell 12 and be electrically connected to the tab connecting portion 1224 of the positive electrode first region 12231.

[0127] The first connecting part 12321 is installed in the positive electrode annular groove 12132, and the first connecting part 12321 and the positive electrode annular groove 12132 are sealed together.

[0128] For example, the positive electrode annular groove 12132 can form a snap-fit ​​structure with the first connecting part 12321 consisting of a first wall, a second wall, and a third wall connected in sequence. The first wall and the third wall are disposed opposite each other on opposite sides of the first connecting part 12321, and the second wall is located on the side of the adapter 1232. In other words, the positive electrode annular groove 12132 forms a three-sided seal for the first connecting part 12321, improving the sealing performance of the battery cell 12. Furthermore, the groove wall of the positive electrode annular groove 12132 located in the first connecting part 12321 facing the cell 1221 can limit the movement of the first connecting part 12321 towards the cell 1221.

[0129] Alternatively, the positive electrode annular groove 12132 can form a first wall and a second wall connected sequentially to the outer edge of the first connecting portion 12321. The first wall can be located on the side of the first connecting portion 12321, and the second wall can be located on the bottom surface of the first connecting portion 12321 facing the cell 1221. The positive electrode annular groove 12132 forms a double-sided seal for the first connecting portion 12321, increasing the sealing performance of the battery cell 12. Furthermore, the groove wall of the positive electrode annular groove 12132 located in the first connecting portion 12321 facing the cell 1221 can limit the movement of the first connecting portion 12321 towards the cell 1221.

[0130] As shown in Figures 6-8, the positive electrode annular groove 12132 can be formed by roller groove upsetting, so that the size of the sealing surface can be more easily controlled within the specifications.

[0131] In actual processing, as shown in Figure 6, the first roller groove forms a stepped surface, that is, the outer shell 121 forms a boss that is concave inward around the axis of the battery cell 12 in the part that extends beyond the cell 1221. The boss can be used to support the first connecting part 12321, thereby restricting the first connecting part 12321 from moving toward the cell 1221, and improving the structural stability and reliability of the battery cell 12.

[0132] Next, the first connecting part 12321 is installed on the step surface, as shown in Figure 7. The outer shell 121 is bent beyond the first connecting part 12321 to form a seal, the bending angle of this part is increased to form a second seal, and then pressed down to form a third seal, thereby forming a positive annular groove 12132 on the outer shell 121, realizing the installation of the outer shell 121 and the first connecting part 12321.

[0133] The first connecting part 12321 is connected to the positive electrode annular groove 12132 in a concave-convex fit, which can effectively reduce the leakage of electrolyte and other substances inside the battery cell 12 to the external environment and improve the sealing performance of the battery. At the same time, the design of the positive electrode annular groove 12132 makes the internal structure of the battery cell 12 more compact and reasonable, which helps to optimize the overall performance and reliability of the battery.

[0134] The first connecting part 12321 and the positive electrode annular groove 12132 can be sealed using various methods. For example, sealing materials such as sealant, sealing rings or sealing gaskets can be used to fill the gap between the first connecting part 12321 and the positive electrode annular groove 12132; in addition, a sealing effect can also be achieved through specific mechanical structures (such as threads or snaps).

[0135] The second connection part 12322 extends from the end opposite to the first connection part 12321 toward the cell 1221 and is electrically connected to the positive electrode first region 12231. This design allows current to be transmitted from the positive electrode first region 12231 to the electrode body 1231 through the adapter 1232, thereby completing the charging and discharging process of the battery.

[0136] The positive electrode first region 12231 is connected to at least two end faces of the second connecting portion 12322, thereby increasing the radial overlap area between the positive electrode first region 12231 and the second connecting portion 12322, thereby increasing the effective flow area during side welding.

[0137] In this embodiment, by configuring the adapter 1232 as a connected first connection portion 12321 and a connected second connection portion 12322, the adapter 1232 is used to achieve effective current transmission and mechanical support in the positive electrode portion of the battery assembly.

[0138] Secondly, as shown in Figures 21 and 22, the portion of the outer casing 121 that protrudes from the positive end of the cell 1221 includes a flange 1215 that folds inward toward the axis of the battery cell 12; the adapter 1232 is provided with a mounting ring groove 12323 extending around the axis of the battery cell 12, the opening of the mounting ring groove 12323 facing outward from the receiving cavity 1211, and at least a portion of the flange 1215 is located within the mounting ring groove 12323 and is sealed to the mounting ring groove 12323.

[0139] The design of the flange 1215 not only enhances the structural strength of the housing 121, but also provides a reliable sealing interface for the installation of the adapter 1232. The flange 1215 may be formed by bending, stamping or other manufacturing processes to ensure that it can fit tightly with the adapter 1232.

[0140] Mounting groove 12323 is used to receive flange 1215 on housing 121. Mounting groove 12323 may have a profile that matches flange 1215 so that the two can fit tightly together and achieve a seal.

[0141] At least a portion of the flange 1215 is located within the mounting ring groove 12323, and the flange 1215 and the mounting ring groove 12323 achieve a sealed connection. This sealed connection can be achieved by welding, sealant, compression sealing, or other sealing techniques. The seal between the flange 1215 and the mounting ring groove 12323 reduces the ingress of external moisture, dust, or other contaminants into the battery cell 12, thereby protecting the cell 1221 and other internal components.

[0142] In this embodiment, the assembly of the flange 1215 on the outer casing 121 and the mounting ring groove 12323 on the adapter 1232 can provide a reliable sealing and mounting structure for the battery cell 12, which helps to improve the sealing performance, structural strength and safety of the battery cell 12.

[0143] In the above two mounting structures of the positive end of the battery cell 12, the shell of the outer casing 121 and the adapter 1232 can form a concave-convex fit connection, which helps to improve the sealing performance, structural strength and safety of the battery cell 12.

[0144] Among them, the negative terminal of the battery cell 12 has at least the following two structures.

[0145] Firstly, as shown in Figures 7 and 23, the negative terminal wall 1214, the first negative electrode region 12221, and the second negative electrode region 12222 of the outer casing 121 are stacked sequentially along the axis of the battery cell 12, which can shorten the axial length of the battery cell 12.

[0146] The negative end wall 1214 of the outer shell 121 can be a flat wall structure. The negative first region 12221 is welded to the negative end wall 1214 of the outer shell 121 to achieve effective current flow. The negative first region 12221 and the negative second region 12222 can be connected by pressing and stacking.

[0147] In actual processing, as shown in Figures 3 and 16, the negative electrode first zone 12221 is first ultrasonically welded to the outer shell 121 through the welding head 40 to form an electrical connection as the negative electrode. As shown in Figures 4 and 17, the excess part of the outer shell 121 is sealed by heating and spinning to complete the sealing of the battery cell 1221.

[0148] Secondly, as shown in Figure 15, the battery cell 12 also includes a negative terminal cover 125, which is installed on the negative terminal opening of the housing 121.

[0149] The negative terminal cap 125 is used to seal the negative terminal opening of the outer casing 121, as shown in Figures 9-11. The negative terminal cap 125 can seal the negative terminal opening of the outer casing 121 by means of pressing, welding or crimping.

[0150] The negative terminal cover 125 is separated from the negative terminal second region 12222 to reserve an explosion-proof gap inside the battery cell 12, thereby improving the reliability and safety of the battery cell 12.

[0151] According to some embodiments of this application, an explosion-proof valve may be provided on the negative end cap 125. When the pressure inside the housing 121 is greater than a certain threshold, the explosion-proof valve opens, thereby releasing the pressure inside the housing 121, reducing the possibility of the battery cell 12 exploding, and improving the safety of the battery cell 12.

[0152] According to some embodiments of this application, as shown in FIG15, the portion of the housing 121 that protrudes from the cell 1221 at the negative terminal includes a first portion 1212 and a second portion 1213. The second portion 1213 is located at the end of the housing 121, and the negative terminal cover 125 is installed on the second portion 1213. The negative terminal first region 12221 is electrically connected to the first portion 1212.

[0153] The first part 1212 and the second part 1213 can be integrally formed or welded structures.

[0154] The first part 1212 and the second part 1213 are arranged along the height direction of the battery cell 12. The second part 1213 is kept at a certain distance from the cell 1221, which can form a certain space. This space can be used to accommodate some components of the battery cell 12 or as part of the explosion-proof gap. The second part 1213 is located at the end of the housing 121 and can be used to install the negative terminal cover 125.

[0155] As shown in Figure 12, the tab connection 1224 of the negative electrode first region 12221 can be electrically connected to the first part 1212 of the outer casing 121 by side welding. This electrical connection can be achieved by ultrasonic roll welding, laser side welding or other reliable connection methods performed by the roll welding head 40.

[0156] At least one of the first part 1212 and the second part 1213 may be provided with a bending structure. The bending structure can shorten the height of the battery cell 12 along the axis and at the same time reserve a certain deformation margin for the outer casing 121 so that the outer casing 121 can undergo axial tensile deformation when the cell 1221 is heated and expands or when the gas pressure inside the outer casing 121 is large, thereby reducing the pressure inside the outer casing 121 and improving the safety of the battery cell 12.

[0157] Alternatively, the first part 1212 and the second part 1213 can be bent relative to each other to form a stacked structure, thereby increasing the deformation allowance of the outer shell 121 at the negative end.

[0158] According to some embodiments of this application, as shown in FIG15, at least a portion of the first part 1212, the first negative electrode region 12221 and the second negative electrode region 12222 are stacked sequentially along the axis of the battery cell 12, and the first negative electrode region 12221 and the second negative electrode region 12222 are close to or in contact with each other.

[0159] It should be noted that after at least a portion of the first part 1212 and the negative electrode first region 12221 are electrically connected by side welding or other means, the portion of the outer casing 121 that protrudes from the cell 1221 at the negative end needs to be sealed by heating, spinning or pressing. During the sealing process, the portion of the outer casing 121 that protrudes from the cell 1221 at the negative end will deform toward the axis of the battery cell 12, and the first part 1212 and the negative electrode first region 12221 will be bent and deformed to be close to or in contact with the negative electrode second region 12222.

[0160] In this embodiment, at least a portion of the first part 1212, the first negative electrode region 12221, and the second negative electrode region 12222 are stacked sequentially along the axis of the battery cell 12. This layout makes the internal structure of the battery cell 12 more compact, improves space utilization, and also helps to improve the safety and reliability of the battery cell 12.

[0161] According to some embodiments of this application, as shown in FIG15, the second part 1213 is provided with a negative electrode annular groove 12131, the groove opening of the negative electrode annular groove 12131 faces the axis of the battery cell 12, and the negative electrode end cap 125 is installed in the negative electrode annular groove 12131 and is sealed with the negative electrode annular groove 12131.

[0162] At least a portion of the outer edge of the negative electrode cap 125 is located within the negative electrode annular groove 12131.

[0163] For example, the negative electrode annular groove 12131 can form a snap-fit ​​structure with the negative electrode cap 125 consisting of a first wall, a second wall, and a third wall connected in sequence. The first wall and the third wall are disposed opposite to each other on opposite sides of the negative electrode cap 125, and the second wall is located on the side of the negative electrode cap 125. In other words, the negative electrode annular groove 12131 forms a three-sided seal for the negative electrode cap 125, improving the sealing performance of the battery cell 12. Furthermore, the groove wall of the negative electrode annular groove 12131 facing the cell 1221 can limit the negative electrode cap 125, restricting the movement of the negative electrode cap 125 toward the cell 1221.

[0164] Alternatively, the negative electrode annular groove 12131 can form a first wall and a second wall connected sequentially to the outer edge of the negative electrode cap 125. The first wall can be located on the side of the negative electrode cap 125, and the second wall can be located on the bottom surface of the negative electrode cap 125 facing the cell 1221. The negative electrode annular groove 12131 forms a double-sided seal for the negative electrode cap 125, increasing the sealing performance of the battery cell 12. Furthermore, the groove wall of the negative electrode annular groove 12131 facing the cell 1221 can limit the movement of the negative electrode cap 125 towards the cell 1221.

[0165] The negative electrode annular groove 12131 can be formed by roller groove upsetting.

[0166] In actual processing, as shown in Figure 9, the roller groove first forms a stepped surface, that is, the outer shell 121 forms an inwardly recessed boss around the axis of the battery cell 12 in the part that extends beyond the cell 1221. The boss can be used to support the negative terminal cover 125, thereby restricting the movement of the negative terminal cover 125 toward the cell 1221 and improving the structural stability and reliability of the battery cell 12.

[0167] As shown in Figure 10, the negative end cap 125 is then installed on the stepped surface. The outer shell 121 is bent at the part that extends beyond the negative end cap 125 to seal it. The bending angle of this part is increased to seal it a second time. The pressure is then continued to seal it a third time, thereby forming a negative annular groove 12131 on the outer shell 121, thus achieving a seal between the outer shell 121 and the negative end cap 125.

[0168] As shown in Figure 11, the negative terminal cap 125 is connected to the negative terminal annular groove 12131 with a concave-convex fit, which can effectively reduce the leakage of electrolyte and other substances inside the battery cell 12 to the external environment and improve the sealing performance of the battery. At the same time, the design of the negative terminal annular groove 12131 makes the internal structure of the battery cell 12 more compact and reasonable, which helps to optimize the overall performance and reliability of the battery.

[0169] The negative end cap 125 and the negative annular groove 12131 can be sealed using various methods. For example, sealing materials such as sealant, sealing rings, or sealing gaskets can be used to fill the gap between the negative end cap 125 and the negative annular groove 12131; in addition, a sealing effect can also be achieved through specific mechanical structures (such as threads or snaps).

[0170] According to some embodiments of this application, as shown in FIG15, the battery cell 12 further includes a sealing insulation member 124.

[0171] At least a portion of the sealing and insulating member 124 located at the negative terminal is situated between the negative terminal cover 125 and the negative terminal annular groove 12131. The sealing and insulating member 124 has both insulating and sealing functions, filling the gap between the negative terminal cover 125 and the negative terminal annular groove 12131 to form a seal between the negative terminal cover 125 and the negative terminal annular groove 12131, thereby reducing the leakage of liquid inside the battery cell 12 from the gap between the negative terminal cover 125 and the negative terminal annular groove 12131. At the same time, it insulates the negative terminal cover 125 and the negative terminal annular groove 12131, reducing short circuits and improving the reliability and safety of the battery cell 12.

[0172] At least a portion of the sealing and insulating member 124 located at the positive terminal is located between the adapter 1232 and the positive annular groove 12132, and at least a portion is located between the positive first region 12231 and the outer casing 121. The sealing and insulating member 124 has both insulating and sealing functions. It is used to fill the gap between the adapter 1232 and the positive annular groove 12132 to form a seal between the adapter 1232 and the positive annular groove 12132, reducing the leakage of liquid inside the battery cell 12 from the gap between the adapter 1232 and the positive annular groove 12132. At the same time, it insulates the adapter 1232 from the positive annular groove 12132 and the positive first region 12231 from the outer casing 121, reducing short circuits and improving the reliability and safety of the battery cell 12.

[0173] For example, the sealing insulation component 124 can be a rubber component, a ceramic component, or a polytetrafluoroethylene component, etc.

[0174] According to some embodiments of this application, as shown in FIG15, the sealing insulation member 124 located at the negative electrode includes a bent section 1241 located between the negative end cap 125 and the negative electrode second region 12222.

[0175] The sealing insulation component 124 located at the negative end includes a sealing section and a bending section 1241. The sealing section is installed between the negative end cover 125 and the outer shell 121 and is used for sealing between the negative end cover 125 and the outer shell 121. The bending section 1241 is located outside the negative end annular groove 12131. One end of the bending section 1241 can be connected to the sealing section, and the end of the bending section 1241 away from the sealing section extends toward the cell 1221.

[0176] Understandably, the bending section 1241 can serve as an auxiliary positioning and limiting function. Since the positive annular groove 12132 and the negative annular groove 12131 at the positive end of the outer shell 121 are not perfectly round, the bending section 1241 can reduce the risk of warping and eccentricity of the sealing insulation component 124. The bending section 1241 can increase the structural strength of the sealing insulation component 124, increase the sealing performance, and reduce the risk of frictional damage between the inner ring of the sealing insulation component 124 and the outer shell 121, as well as between the inner ring of the sealing insulation component 124 and the negative end cap 125.

[0177] In this embodiment, by providing the bending section 1241, the length of the sealing insulation component 124 can be extended. The connection area between different components within the battery cell 12 may have irregular shapes or spatial limitations. The bending section 1241 can flexibly conform to these complex shapes, so that the sealing insulation component 124 can be effectively installed and positioned. At the same time, during the operation of the battery cell 12, due to changes in factors such as temperature and pressure, the components within the battery cell 12 may undergo slight movements or deformations. The design of the bending section 1241 can absorb these changes, reduce stress concentration, and thus extend the service life of the sealing insulation component 124.

[0178] In some embodiments, the sealing insulation member 124 of the negative terminal includes a first segment to a fourth segment connected in sequence. At least a portion of the first segment is located between the groove wall of the negative annular groove 12131 away from the first portion 1212 and the negative terminal cover 125. The second segment is located between the bottom wall of the negative annular groove 12131 and the negative terminal cover 125. The third segment is located between the groove wall of the negative annular groove 12131 near the first portion 1212 and the negative terminal cover 125. The fourth segment is located outside the negative annular groove 12131 and extends toward the cell 1221 to form a bent segment 1241.

[0179] The first to fourth sections can be designed as a single piece.

[0180] The first to third sections are installed between the negative electrode annular groove 12131 and the negative electrode end cap 125, serving as a seal and insulation between them. The fourth section is located between the negative electrode annular groove 12131 and the negative electrode second zone 12222, and can be used to compensate for the length of the sealing insulation component 124 and limit the displacement of the negative electrode end cap 125, thereby improving the structural stability and positioning effect of the sealing insulation component 124.

[0181] For example, the bending shape of the first to fourth segments of the sealing insulation member 124 can be manufactured during production; or, the sealing insulation member 124 can be deformed to form the bending shape of the first to fourth segments according to the shape change of the mating surface between the housing 121 and the negative end cap 125.

[0182] According to some embodiments of this application, the end of the first segment that is away from the second segment is located outside the negative electrode annular groove 12131, and the end of the third segment that is away from the second segment is located outside the negative electrode annular groove 12131.

[0183] The first and third segments have a length allowance. Each segment includes a portion between the negative electrode annular groove 12131 and the negative electrode cap 125, and a portion outside the negative electrode annular groove 12131. This enhances the stability of the sealing insulation component 124 and helps reduce the risk of seal failure caused by deformation of the sealing insulation component 124 due to vibration or temperature changes during the operation of the battery cell 12. Simultaneously, it simplifies the installation and removal process of the sealing insulation component 124, making it easier for operators to insert the sealing insulation component 124 between the negative electrode annular groove 12131 and the negative electrode cap 125 to form an effective seal. Furthermore, due to the length allowance, it can be adjusted according to the specific shape and size of the negative electrode annular groove 12131 to suit different types of batteries, helping to reduce production costs and meet the customized needs of different customers.

[0184] According to some embodiments of this application, the end of the first segment that is away from the second segment is located outside the negative electrode annular groove 12131.

[0185] The first section has a length margin and includes the portion located between the negative electrode annular groove 12131 and the negative electrode end cap 125 and the portion located outside the negative electrode annular groove 12131. This can enhance the stability of the sealing insulation component 124 and help reduce the risk of sealing failure caused by deformation of the sealing insulation component 124 due to vibration or temperature changes generated during the operation of the battery cell 12.

[0186] According to some embodiments of this application, the end of the third segment that is away from the second segment is located outside the negative electrode annular groove 12131.

[0187] The third section has a length margin and includes the portion located between the negative electrode annular groove 12131 and the negative electrode end cap 125 and the portion located outside the negative electrode annular groove 12131. This can enhance the stability of the sealing insulation component 124 and help reduce the risk of sealing failure caused by deformation of the sealing insulation component 124 due to vibration or temperature changes generated during the operation of the battery cell 12.

[0188] According to some embodiments of this application, the sealing insulation 124 located at the positive end includes an extension located between the adapter 1232 and the positive second region 12232.

[0189] The sealing and insulating component 124 located at the positive end includes a sealing section and an extension section. The sealing section is installed between the adapter 1232 and the outer shell 121 and is used for sealing and insulation between the adapter 1232 and the outer shell 121. The extension section is located outside the positive annular groove 12132 and between the positive first region 12231 and the outer shell 121. The extension section can be used for insulation between the positive first region 12231 and the outer shell 121, and one end of the extension section can be connected to the sealing section.

[0190] The following describes the battery cell 12 provided in this application using three complete embodiments.

[0191] Firstly, as shown in Figure 3, the second negative electrode region 12222 of the inner ring on the negative electrode side is flattened and electrically connected to the battery cell 1221. The first negative electrode region 12221 of the outer ring is electrically connected to the outer shell 121 by ultrasonic roll welding. As shown in Figures 4 and 5, the excess portion of the outer shell 121 extending axially beyond the battery cell 1221 on the negative electrode side is sealed by heating and spinning. As shown in Figure 6, the second positive electrode region 12232 of the inner ring on the positive electrode side is flattened and electrically connected to the battery cell 1221. The first positive electrode region 12231 of the outer ring is welded to the adapter 1232 to form an electrical connection. As shown in Figure 7, the excess portion of the outer shell 121 extending axially beyond the battery cell 1221 on the positive electrode side is rolled and grooved for sealing. As shown in Figure 8, after liquid injection, the electrode body 1231 is sealed by welding sealing nails.

[0192] Secondly, as shown in Figure 3, the negative electrode second region 12222 on the inner ring of the negative electrode side is flattened and electrically connected to the battery cell 1221. The negative electrode first region 12221 on the outer ring is electrically connected to the outer shell 121 by ultrasonic roll welding. As shown in Figures 9 and 10, the excess portion of the outer shell 121 extending axially beyond the battery cell 1221 on the negative electrode side is sealed by roller groove upset sealing. As shown in Figure 11, the negative electrode cap is located in the negative electrode annular groove. The positive electrode second region 12232 on the inner ring of the positive electrode side is flattened and electrically connected to the battery cell 1221. As shown in Figure 12, the positive electrode first region 12231 on the outer ring is welded to the adapter 1232 to form an electrical connection. As shown in Figures 13 and 14, the excess portion of the outer shell 121 extending axially beyond the battery cell 1221 on the positive electrode side is roller groove upset sealing. As shown in Figure 15, after liquid injection, the electrode body 1231 is sealed by welding sealing nails.

[0193] Third, the inner ring negative electrode second region 12222 on the negative electrode side is flattened and electrically connected to the battery cell 1221, as shown in Figure 16. The outer ring negative electrode first region 12221 is electrically connected to the outer shell 121 by ultrasonic roll welding, as shown in Figures 17 and 18. The excess part of the outer shell 121 extending axially beyond the battery cell 1221 on the negative electrode side is sealed by heating and spinning. The inner ring positive electrode second region 12232 on the positive electrode side is flattened and electrically connected to the battery cell 1221, as shown in Figure 19. The outer ring positive electrode first region 12231 is welded to the adapter 1232 to form an electrical connection, as shown in Figure 20. The excess part of the outer shell 121 extending axially beyond the battery cell 1221 on the positive electrode side is spun, as shown in Figure 21. The adapter 1232 is riveted with a flange 1215, as shown in Figure 22. After liquid injection, the electrode body 1231 is sealed by welding with sealing nails.

[0194] In the three specific embodiments described above, the sealing methods of the negative electrode side of the outer casing 121 are different. The negative electrode opening of the outer casing 121 can be sealed inward by heating and spinning to shorten the axial height of the battery cell 12. Alternatively, it can be sealed by roller groove upset sealing, which can leave an explosion-proof space for the battery cell 12, reduce the explosion-proof risk of the battery cell 12, and improve safety. The structure of the adapter 1232 at the positive electrode of the outer casing 121 is different, but all of them can achieve a concave-convex fit and sealed insulation connection between the adapter 1232 and the outer casing 121.

[0195] According to some embodiments of this application, this application also provides a battery, including: a plurality of battery cells 12 as described in any of the embodiments above.

[0196] The battery provided in this application embodiment can achieve the effects of the battery cell 12 described above by using the battery cell 12 in any of the above embodiments, thereby improving the reliability and safety of the battery.

[0197] According to some embodiments of this application, this application also provides an electrical device, including: a battery as described in the above embodiments, the battery being used to provide electrical energy to the electrical device.

[0198] The electrical device can be any of the aforementioned battery-powered devices or systems.

[0199] The electrical device provided in this application embodiment can achieve the effects of the battery described above by using the battery in any of the above embodiments, thereby improving the reliability and safety of the electrical device.

[0200] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0201] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: The outer shell forms a receiving cavity; An electrode assembly is disposed within the receiving cavity, the electrode assembly comprising a battery cell and a first electrode tab and a second electrode tab disposed at both ends of the battery cell; The pole is connected to and insulated from the outer casing; The first electrode includes a first negative electrode region and a second negative electrode region. The first negative electrode region is electrically connected to the outer casing, and the second negative electrode region is stacked on the negative terminal face of the battery cell. The second electrode includes a first positive electrode region and a second positive electrode region. The first positive electrode region is electrically connected to the electrode post, and the second positive electrode region is stacked on the positive terminal face of the battery cell.

2. The battery cell according to claim 1, characterized in that, The second negative electrode region is located in the inner circle relative to the first negative electrode region; and / or, the second positive electrode region is located in the inner circle relative to the first positive electrode region.

3. The battery cell according to claim 1 or 2, characterized in that, The negative electrode first region is continuously arranged around the axis of the battery cell; and / or, the positive electrode first region is continuously arranged around the axis of the battery cell.

4. The battery cell according to claim 1 or 2, characterized in that, At least one of the positive electrode first region and the negative electrode first region includes a plurality of electrode tabs, which are spaced apart.

5. The battery cell according to claim 4, characterized in that, The plurality of electrode connectors are arranged in multiple rings, with multiple electrode connectors in the same ring spaced apart circumferentially, and at least a portion of the electrode connectors in adjacent rings are arranged radially staggered.

6. The battery cell according to any one of claims 1-5, characterized in that, The electrode post includes an electrode post body and an adapter. The adapter is installed on the outer casing. The electrode post body is electrically connected to the positive electrode first region through the adapter. The electrode post body is located at the end of the adapter that is away from the battery cell.

7. The battery cell according to claim 6, characterized in that, The positive electrode first region is connected to at least two walls of the adapter.

8. The battery cell according to claim 6 or 7, characterized in that, The outer casing has a positive annular groove on the portion of the positive terminal that protrudes from the battery cell. The adapter includes a first connecting part and a second connecting part connected together. The first connecting part is installed in the positive electrode annular groove, and the end of the second connecting part opposite to the first connecting part extends toward the battery cell and is electrically connected to the positive electrode first region.

9. The battery cell according to any one of claims 6 or 7, characterized in that, The portion of the outer casing that protrudes from the cell at the positive end includes a flange that folds inward toward the axis of the battery cell; The adapter is provided with a mounting ring groove extending around the axis of the battery cell, the opening of the mounting ring groove facing outward from the receiving cavity, and at least a portion of the flange is located within the mounting ring groove and is sealed to the mounting ring groove.

10. The battery cell according to any one of claims 6-9, characterized in that, The negative end wall of the outer casing, the first negative electrode region, and the second negative electrode region are stacked sequentially along the axis of the battery cell.

11. The battery cell according to any one of claims 6-10, characterized in that, The battery cell also includes a negative terminal cover, which is installed at the negative terminal opening of the housing and is spaced apart from the second negative terminal area.

12. The battery cell according to claim 11, characterized in that, The outer casing, at the negative terminal protruding from the battery cell, comprises a first part and a second part. The second part is located at the end of the outer casing, the negative terminal cap is mounted on the second part, and the negative terminal first region is electrically connected to the first part.

13. A battery, characterized in that, include: Multiple battery cells as described in any one of claims 1-12.

14. An electrical appliance, characterized in that, include: The battery of claim 13 is used to provide electrical energy to the electrical device.

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