Battery monomer, battery and electric device

Abstract

The embodiment of the utility model provides a battery monomer, a battery and a power utilization device, and belongs to the technical field of batteries. Each battery monomer comprises a shell, an electrode assembly and a pole; the shell forms an accommodating cavity; the electrode assembly is arranged in the accommodating cavity and comprises a battery cell as well as a first tab and a second tab which are respectively arranged at two ends of the battery cell; the pole and the shell are insulated, and the pole is electrically connected with the second tab; wherein the first tab comprises a first negative electrode area and a second negative electrode area, the first negative electrode area is electrically connected with the shell, and the second negative electrode area is overlapped with the negative electrode end surface of the battery cell. According to the invention, multiple welding steps in the battery single body can be simplified, the risk of adverse effects caused by welding is reduced, and the reliability of electric connection in the battery single body is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a battery cell, a battery, and an electrical device. Background Technology

[0002] 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. Utility Model Content

[0003] This application provides a battery cell, a battery, and an electrical device to improve the reliability of electrical connections within the battery cell.

[0004] In a first aspect, embodiments of this application provide a single battery cell, comprising:

[0005] The outer shell forms a receiving cavity;

[0006] 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;

[0007] The electrode post is insulated from the outer casing and is electrically connected to the second electrode tab.

[0008] 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.

[0009] In the above technical solution, the negative electrode tab is divided into a first negative electrode region and a second negative electrode region. The first negative electrode region can be directly electrically connected to the casing by side welding, eliminating the need for current collectors such as terminals and adapters, 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. The second negative electrode region is stacked with the negative end face of the cell after being flattened, optimizing the electrical connection between the second negative electrode region and the cell, as well as between adjacent tabs within the second negative electrode region, thereby further improving the reliability of electrical connections within the battery cell.

[0010] In some embodiments, the second negative electrode region is located in the inner circle relative to the first negative electrode region.

[0011] In some embodiments, the negative electrode first region is continuously arranged around the axis of the battery cell.

[0012] In some embodiments, the negative electrode first region includes a plurality of electrode tabs, which are spaced apart.

[0013] In some embodiments, the plurality of tab connections are arranged in multiple loops, with the plurality of tab connections in the same loop spaced apart circumferentially, and at least a portion of the tab connections in adjacent loops being arranged radially staggered.

[0014] In some embodiments, the negative end wall of the housing, the first negative electrode region, and the second negative electrode region are stacked sequentially along the axis of the battery cell.

[0015] In some embodiments, the battery cell further includes a negative terminal cover, which is installed at the negative terminal opening of the housing and spaced apart from the second negative terminal region.

[0016] In some embodiments, the housing includes a first portion and a second portion at the negative terminal protruding from the battery cell, the second portion being located at the end of the housing, the negative terminal cap being mounted on the second portion, and the negative terminal first region being electrically connected to the first portion.

[0017] In some embodiments, at least a portion of the first portion, the first negative electrode region, and the second negative electrode region are stacked sequentially along the axis of the battery cell.

[0018] In some embodiments, the second part is provided with a negative electrode annular groove, the groove opening of the negative electrode annular groove facing the axis of the battery cell, and the negative electrode cap is installed in the negative electrode annular groove and is sealed with the negative electrode annular groove.

[0019] In some embodiments, the battery cell further includes a sealing insulation element, at least a portion of which is located between the negative terminal cap and the negative terminal annular groove.

[0020] In some embodiments, the sealing insulation includes a bent section located between the negative end cap and the negative second region.

[0021] Secondly, embodiments of this application provide a battery comprising: a plurality of battery cells as described in any of the embodiments above.

[0022] 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

[0023] 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.

[0024] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0025] Figure 2 Exploded views of the battery structure provided in some embodiments of this application;

[0026] Figure 3 This is one of the structural schematic diagrams of a battery cell provided in some embodiments of this application;

[0027] Figure 4 This is the second schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0028] Figure 5 This is the third schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0029] Figure 6 Fourth of some embodiments of the present application provides a structural schematic diagram of a battery cell;

[0030] Figure 7 Fifth of some embodiments of the present application provides a structural schematic diagram of a battery cell;

[0031] Figure 8 This is the sixth schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0032] Figure 9 This is the seventh schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0033] Figure 10 This is one of the structural schematic diagrams of the battery cell provided in some embodiments of this application;

[0034] Figure 11 This is the second schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0035] Figure 12 This is the third schematic diagram of the structure of a battery cell provided in some embodiments of this application.

[0036] Figure label:

[0037] Vehicle 1, Battery 10, Box 11, First Box Body 111, Second Box Body 112;

[0038] Battery cell 12, casing 121, receiving cavity 1211, first part 1212, second part 1213, negative electrode annular groove 12131, negative electrode end wall 1214, electrode assembly 122, cell 1221, negative electrode end surface 12211, first electrode tab 1222, negative electrode first region 12221, negative electrode second region 12222, second electrode tab 1223, electrode tab connection part 1224;

[0039] pole 123;

[0040] Sealed insulating component 124, bent section 1241;

[0041] Negative end cap 125, positive end cap 126, injection hole 127, sealing pin 128, insulating pad 129;

[0042] Motor 20, controller 30, welding head 40. Detailed Implementation

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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).

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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 single 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 insulated from the casing, and the terminals are electrically connected to the second electrode tab; 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 on the negative terminal face of the cell.

[0057] In this type of battery cell, the negative electrode tab is divided into a first negative electrode region and a second negative electrode region. The first negative electrode region can be directly electrically connected to the casing by side welding, eliminating the need for current collectors such as terminals and adapters. This simplifies the multiple welding steps, reduces the risk of adverse effects caused by welding, and improves the reliability of electrical connections within the battery cell. The second negative electrode region is flattened and stacked with the negative end face of the cell, optimizing the electrical connections between the second negative electrode region and the cell, as well as between adjacent tabs within the second negative electrode region, thereby further improving the reliability of electrical connections within the battery cell.

[0058] 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.

[0059] 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.

[0060] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device according to an embodiment of this application.

[0061] like Figure 1 As shown, Figure 1 This is a schematic diagram of the structure of a vehicle 1 according to an embodiment of this application. Vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A motor 20, a controller 30, and a battery 10 can be installed inside vehicle 1. The controller 30 is used to control 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 vehicle 1. The battery 10 can be used to power vehicle 1; for example, the battery 10 can serve as the operating power source for vehicle 1's electrical system, such as meeting the power requirements for starting, navigation, and operation of vehicle 1.

[0062] 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.

[0063] 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. A mixed connection refers to a combination of series and parallel connections.

[0064] like Figure 2The diagram shown is 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 overlap 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; alternatively, the first housing body 111 and the second housing body 112 may both be hollow structures 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] According to some embodiments of this application, such as Figure 5 and Figure 9As shown, this application provides a battery cell 12, including: a housing 121, an electrode assembly 122, and a terminal post 123.

[0075] The outer casing 121 forms a receiving cavity 1211, which is used to receive the electrode assembly 122.

[0076] 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.

[0077] 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.

[0078] The terminal 123 is insulated from the outer casing 121. The terminal 123 and the outer casing 121 are isolated by an insulating material, such as ceramic, plastic or rubber, to prevent short circuit between the terminal 123 and the outer casing 121.

[0079] The terminal 123 is electrically connected to the second tab 1223, and the terminal 123 is used to connect to an external circuit. One of the terminal 123 and the housing 121 is the negative terminal, and the other of the terminal 123 and the housing 121 is the negative terminal.

[0080] For example, when the second tab 1223 is the positive tab, the post 123 serves as the post 123, and the positive tab is electrically connected to the external circuit through the post 123. The first tab 1222 is the negative tab, and the first tab 1222 is connected to the outer casing 121. The outer casing 121 is the negative terminal, and the negative tab is electrically connected to the external circuit through the outer casing 121.

[0081] For example, when the second tab 1223 is the negative tab, the post 123 serves as the negative post 123, and the negative tab is electrically connected to the external circuit through the post 123. The first tab 1222 is the positive tab, and the first tab 1222 is connected to the outer casing 121. The outer casing 121 is the positive terminal, and the positive tab is electrically connected to the external circuit through the outer casing 121.

[0082] Among them, such as Figure 3As shown, 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.

[0083] Among them, the negative electrode first region 12221 can be a multi-turn tab connection part arranged radially along the battery cell.

[0084] Before the cell 1221 is assembled with the casing 121, the tab connection 1224 of the negative electrode first region 12221 can be in an upright state; before the cell 1221 is assembled with the casing 121 but the opening of the casing 121 is not sealed, the tab connection 1224 of the negative electrode first region 12221 and the 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 casing 121 by a side welding method along the radial direction.

[0085] For example, such as Figure 3 As shown, the tab connection 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.

[0086] Understandably, due to the thin foil thickness at the edge of the tab, the edge of the tab may be uneven, potentially resulting in flaking and numerous burrs. 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 battery cell 1221, 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 battery cell 1221, and optimize the electrical connection between the flattened area of ​​the tab and the battery cell 1221.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] For example, when the first tab 1222 and the second tab 1223 are respectively located 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.

[0091] In related technologies, electrical connections within the battery cell 12 are mostly achieved through welding. In particular, cylindrical battery cells 12 require the tabs to be flattened to achieve electrical welding connections with the adapter plate. 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.

[0092] The battery cell 12 provided in this application embodiment divides 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, eliminating the need for 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 stacked with the negative end face 12211 of the cell 1221 by flattening treatment, optimizing the electrical connection between the second negative electrode region 12222 and the cell 1221, as well as between adjacent loops within the second negative electrode region 12222, thereby further improving the reliability of electrical connections within the battery cell 12.

[0093] 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 better contact the end of the cell 1221.

[0094] The negative electrode first region 12221 includes a tab connection portion 1224, which may have at least the following structures.

[0095] Firstly, such as Figure 10 and Figure 11 As shown, the negative electrode first region 12221 is continuously arranged around the axis of the battery cell 12.

[0096] Among them, the battery cell 1221 can be a wound type, the tab connection part 1224 of the negative electrode first region 12221 can be a continuous structure without die cutting, and the tab connection part 1224 can be provided with one or more turns along the winding direction.

[0097] In this embodiment, by setting a continuous negative electrode first region 12221 and electrically connecting it to the inner wall of the outer shell 121 by welding or pressing, the uniformity and reliability of the electrical connection between the negative electrode first region 12221 and the outer shell 121 can be improved, and the processing difficulty of connecting the negative electrode first region 12221 and the outer shell 121 can also be reduced.

[0098] Secondly, such as Figure 12 As shown, the negative electrode first region 12221 includes multiple electrode tabs 1224, which are spaced apart.

[0099] In this embodiment, a notch is provided between two adjacent tabs 1224 in the plurality of tabs connected in the same circle. When the negative electrode first region 12221 and the outer shell 121 are stacked, the thickness of the stacked negative electrode first region 12221 can be reduced, thereby reducing the height of the cell 1221 along the axial direction and reducing the weight of the battery cell 12.

[0100] According to some embodiments of this application, such as Figure 12 As shown, multiple electrode connectors 1224 are arranged in multiple rings, and the multiple electrode connectors 1224 in the same ring are spaced apart circumferentially. For example, the multiple electrode connectors 1224 in the same ring can be evenly spaced apart circumferentially.

[0101] At least some of the tab connection portions 1224 in two adjacent rings are arranged radially staggered. Some of the tab connection portions 1224 in the previous ring are located above or below the gap between adjacent tab connection portions 1224 in the next ring. In other words, the radial projection of the multiple tab connection portions 1224 in the negative electrode first region 12221 is a continuous structure. The radial projection of the negative electrode first region 12221 does not have any gaps, which can facilitate the continuity of welding between the negative electrode first region 12221 and the outer shell 121, reduce the welding difficulty, and improve the uniformity and reliability of the electrical connection between the negative electrode first region 12221 and the outer shell 121.

[0102] Among them, the battery cell 12 includes at least the following two structures:

[0103] Firstly, such as Figure 5 As shown, 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.

[0104] 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.

[0105] In actual processing, such as Figure 3 and Figure 4 As shown, the first negative electrode region 12221 is ultrasonically welded to the outer shell 121 through the welding head 40 to form an electrical connection as the negative electrode. The excess part of the outer shell 121 is sealed by heating and spinning to complete the sealing of the battery cell 1221.

[0106] Secondly, such as Figure 9 As shown, the battery cell 12 also includes a negative terminal cover 125, which is installed at the negative terminal opening of the housing 121.

[0107] The negative terminal cap 125 is used to close the negative terminal opening of the housing 121, such as... Figures 7-9 As shown, the negative terminal cover 125 can seal the negative terminal opening of the outer casing 121 by means of sealing, welding or pressing.

[0108] 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.

[0109] In some embodiments, an explosion-proof valve is provided on the negative end cap 125. When the pressure inside the housing 121 exceeds 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.

[0110] According to some embodiments of this application, such as Figure 10 As shown, 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.

[0111] The first part 1212 and the second part 1213 can be integrally formed or welded structures.

[0112] 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.

[0113] like Figure 6 As shown, 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 ultrasonic welding, laser side welding or other reliable connection methods performed by the welding head 40.

[0114] 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.

[0115] 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.

[0116] According to some embodiments of this application, such as Figure 7 As shown, 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, with the first negative electrode region 12221 and the second negative electrode region 12222 being close to or in contact with each other.

[0117] 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.

[0118] 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.

[0119] According to some embodiments of this application, such as Figure 9As shown, the second part 1213 is provided with a negative electrode annular groove 12131. The groove of the negative electrode annular groove 12131 faces the axis of the battery cell 12. The negative electrode cap 125 is installed in the negative electrode annular groove 12131 and is sealed with the negative electrode annular groove 12131.

[0120] At least a portion of the outer edge of the negative electrode cap 125 is located within the negative electrode annular groove 12131.

[0121] 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 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 located on the negative electrode cap 125 facing the cell 1221 can limit the movement of the negative electrode cap 125 towards the cell 1221.

[0122] 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 located on the negative electrode cap 125 facing the cell 1221 can limit the movement of the negative electrode cap 125 towards the cell 1221.

[0123] The negative electrode annular groove 12131 can be formed by roller groove upsetting, so that the size of the sealing surface can be more easily controlled within the specifications.

[0124] In actual processing, such as Figure 7 As shown, the first roller groove 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.

[0125] like Figure 8 and Figure 9 As shown, the negative terminal cap 125 is then installed on the stepped surface. The outer shell 121 is bent at the part that extends beyond the negative terminal cap 125 to seal it. The bending angle of this part is increased to seal it a second time. The shell is then pressed down 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 terminal cap 125.

[0126] 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.

[0127] 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).

[0128] According to some embodiments of this application, such as Figure 9 As shown, the battery cell 12 also includes a sealing insulation member 124, at least a portion of which is located between the negative terminal cap 125 and the negative terminal annular groove 12131.

[0129] The sealing and insulating component 124 has both insulating and sealing functions. It is used to fill the gap between the negative terminal cover 125 and the negative terminal annular groove 12131, so that a seal is formed between the negative terminal cover 125 and the negative terminal annular groove 12131, 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.

[0130] For example, the sealing insulation component 124 can be a rubber component, a ceramic component, or a polytetrafluoroethylene component, etc.

[0131] According to some embodiments of this application, such as Figure 9 As shown, the sealing insulation member 124 includes a bent section 1241 located between the negative terminal cover 125 and the negative terminal second region 12222.

[0132] The sealing insulation component 124 includes a sealing section and a bending section. The sealing section is installed between the negative terminal cover 125 and the outer shell 121 and is used for sealing between the negative terminal cover 125 and the outer shell 121. The bending section is located outside the negative terminal annular groove 12131. One end of the bending section can be connected to the sealing section, and the end of the bending section away from the sealing section extends toward the cell 1221.

[0133] Understandably, the bending section can serve as an auxiliary positioning and limiting function. Since the negative electrode annular groove 12131 is not a perfect circle, setting the bending section can reduce the risk of the sealing insulation component 124 warping and becoming eccentric. The bending section 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.

[0134] By incorporating a bending section, 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, enabling the sealing insulation component 124 to be effectively installed and positioned. Simultaneously, 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.

[0135] For example, the sealing insulation member 124 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 end cap 125. The second segment is located between the bottom wall of the negative annular groove 12131 and the negative end cap 125. The third segment is located between the groove wall of the negative annular groove 12131 near the first portion 1212 and the negative end cap 125. The fourth segment is located outside the negative annular groove 12131 and extends toward the cell 1221 to form a bent segment 1241.

[0136] The first to fourth sections can be designed as a single piece.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] According to some embodiments of this application, such as Figure 9As shown, the positive terminal of the battery cell 12 includes a positive electrode flattening layer formed by flattening the second electrode tab 1223, a positive electrode adapter piece, a terminal post 123, and a positive terminal cover 126. The positive electrode flattening layer and the positive terminal of the cell 1221 are stacked. The positive electrode flattening layer, the positive electrode flattening layer, and the positive electrode adapter piece are welded to form an electrical connection. The terminal post 123 is electrically connected to the positive electrode adapter piece. The terminal post 123 extends to the outside of the positive terminal cover 126, and both the terminal post 123 and the positive electrode adapter piece are insulated from the outer casing 121.

[0146] An insulating pad 129 may be provided between the positive electrode adapter and the outer casing 121.

[0147] According to some embodiments of this application, the terminal post 123 is provided with a liquid injection hole 127, and the battery cell 12 also includes a sealing pin 128. The liquid injection hole 127 is used for liquid injection, and the sealing pin 128 is used for sealing the liquid injection hole 127. After the liquid injection of the battery cell 12 is completed, the sealing pin 128 is assembled with the liquid injection hole 127 to seal the liquid injection hole 127.

[0148] The following describes the battery cell 12 provided in this application using two complete embodiments.

[0149] Firstly, such as Figure 5 As shown, the battery cell 12 includes: a housing 121, an electrode assembly 122, and a terminal post 123. The electrode assembly 122 is disposed in the receiving cavity 1211. The electrode assembly 122 includes a cell 1221 and a first tab 1222 and a second tab 1223 disposed at both ends of the cell 1221. The first tab 1222 is the negative tab, and the second tab 1223 is the positive tab.

[0150] The positive electrode tab can employ an electrical connection scheme from related technologies. The positive electrode tab is flattened and then welded to the positive electrode adapter piece. The positive electrode adapter piece is welded to the electrode post 123 to form the positive electrode. The negative electrode tab includes a second negative electrode region 12222 located in the inner ring and a first negative electrode region 12221 located in the outer ring. The second negative electrode region 12222 is flattened and electrically connected to the battery cell 1221. The first negative electrode region 12221 is electrically connected to the outer casing 121 via ultrasonic roll welding to form the negative electrode. See [link to relevant documentation]. Figure 3 .

[0151] like Figure 4 and Figure 5 As shown, the excess portion of the outer casing 121 along the axis that extends beyond the height of the battery cell 1221 is sealed by heating and spinning to achieve the sealing of the battery cell 1221.

[0152] Secondly, the battery cell 12 includes: a casing 121, an electrode assembly 122 and a terminal post 123. The electrode assembly 122 is disposed in the receiving cavity 1211. The electrode assembly 122 includes a cell 1221 and a first tab 1222 and a second tab 1223 disposed at both ends of the cell 1221. The first tab 1222 is the negative tab and the second tab 1223 is the positive tab.

[0153] The positive electrode tab can employ an electrical connection scheme from related technologies. The positive electrode tab is flattened and then welded to the positive electrode adapter piece. The positive electrode adapter piece is welded to the electrode post 123 to form the positive electrode. The negative electrode tab includes a second negative electrode region 12222 located in the inner ring and a first negative electrode region 12221 located in the outer ring. The second negative electrode region 12222 is flattened and electrically connected to the battery cell 1221. The first negative electrode region 12221 is electrically connected to the outer casing 121 via ultrasonic roll welding to form the negative electrode. See [link to relevant documentation]. Figure 6 .

[0154] The excess portion of the outer casing 121 extending beyond the height of the battery cell 1221 along the axis is sealed using a roller groove for upsetting, thus completing the sealing of the battery cell 1221. See [link to documentation]. Figures 7-9 .

[0155] In the two specific embodiments described above, the sealing methods of the outer casing 121 are different. The opening of the outer casing 121 can be sealed 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.

[0156] 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.

[0157] 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.

[0158] 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.

[0159] The electrical device can be any of the aforementioned battery-powered devices or systems.

[0160] 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.

[0161] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0162] 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 by, The battery cell comprises: a housing forming a receiving cavity; an electrode assembly disposed in the receiving cavity, the electrode assembly comprising an electrode core and a first tab and a second tab disposed at two ends of the electrode core; a post disposed in an insulated manner with respect to the housing, the post being electrically connected with the second tab; wherein the first tab comprises a negative first region and a negative second region, the negative first region being electrically connected with the housing, and the negative second region being superposed with a negative end surface of the electrode core.

2. The battery cell of claim 1, wherein, The negative second region is located in an inner circle with respect to the negative first region.

3. The battery cell according to claim 1 or 2, characterized in that, The negative first region is continuously disposed around an axis of the battery cell.

4. The battery cell according to any one of claims 1 or 2, characterized in that, The negative first region comprises a plurality of tab connecting portions, the plurality of tab connecting portions being disposed in a spaced apart manner.

5. The battery cell of claim 4, wherein, The plurality of tab connecting portions are arranged in a plurality of circles, the plurality of tab connecting portions in a same circle being disposed in a spaced apart manner in a circumferential direction, and at least part of the tab connecting portions of adjacent two circles being disposed in a staggered manner in a radial direction.

6. The battery cell of any one of claims 1-5, wherein, A negative end wall of the housing, the negative first region, and the negative second region are sequentially superposed along the axis of the battery cell.

7. The battery cell of any one of claims 1-5, wherein, The battery cell further comprises a negative end cover, the negative end cover being mounted to a negative opening of the housing and being spaced apart from the negative second region.

8. The battery cell according to claim 7, wherein: the housing comprises a first portion and a second portion at a portion protruding from the electrode core in a negative end direction, the second portion being located at an end portion of the housing, the negative end cover being mounted to the second portion, and the negative first region being electrically connected with the first portion.

9. The battery cell of claim 8, wherein, At least part of the first portion, the negative first region, and the negative second region are sequentially superposed along the axis of the battery cell.

10. The battery cell according to claim 8 or 9, characterized in that, The second portion is provided with a negative annular groove, an opening of the negative annular groove facing the axis of the battery cell, the negative end cover being mounted to the negative annular groove and being disposed in a sealed manner with respect to the negative annular groove.

11. The battery cell of claim 10, wherein, The battery cell further comprises a sealing insulation member, at least part of the sealing insulation member being located between the negative end cover and the negative annular groove.

12. A battery, characterized by The battery cell comprises: a plurality of battery cells according to any one of claims 1-11.

13. An electrical device, comprising: The battery comprises: the battery according to claim 12, the battery being used to provide electric energy for the electric device.

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