Battery monomer and preparation method thereof, battery device and power utilization device

Abstract

The invention discloses a battery monomer and a preparation method thereof, a battery device and a power utilization device. The battery monomer comprises a shell, an electrode assembly and colloid; the electrode assembly is arranged in the shell and comprises an electrode main body and a tab arranged on one side of the electrode main body; the colloid is arranged on the periphery of the electrode body and located at the position, close to the tab, of the electrode body. The lithium precipitation phenomenon of the electrode assembly when the battery monomer works can be reduced.

Description

Battery cells and their preparation methods, battery devices and electrical devices Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell and its preparation method, a battery device, and an electrical device. Background Technology

[0002] In recent years, with the rapid development of new energy technologies, new energy vehicles have been increasingly widely used and are gradually replacing traditional fuel vehicles, becoming one of the mainstream modes of transportation. As the power source of new energy vehicles, the power battery is one of their core components; therefore, the safety performance of the power battery has become a key focus of attention.

[0003] In the development of battery technology, how to reduce lithium plating in battery cells is a research direction. Summary of the Invention

[0004] This application provides a battery cell and its preparation method, a battery device, and an electrical device, which can reduce lithium plating in the battery cell.

[0005] In a first aspect, embodiments of this application provide a battery cell, which includes a housing, an electrode assembly, and a gel. The electrode assembly is disposed within the housing and includes an electrode body and a tab disposed on one side of the electrode body. The gel is disposed on the outer periphery of the electrode body and is located near the tab of the electrode body.

[0006] In the above scheme, a gel is provided on the outer periphery of the electrode body near the tab. The gel binds the head of the electrode body (i.e., the position near the tab), which can reduce the distance between the electrode heads, thereby reducing lithium plating at the electrode assembly head when the battery cell is working and improving safety.

[0007] In some embodiments, the colloid is continuously disposed around the outer periphery of the electrode body.

[0008] In the above scheme, the colloid can exert a binding force on the electrode body in all directions, which can further reduce the lithium plating phenomenon at the head of the electrode assembly.

[0009] In some embodiments, the battery cell further includes an insulating film disposed on the outer periphery of the electrode body, the insulating film being connected to the colloid, and at least a portion of the insulating film being disposed on the side of the colloid away from the tab.

[0010] In the above scheme, by wrapping the electrode body with an insulating film, a constraint force can be provided on the electrode body. Moreover, at least part of the insulating film is placed on the side of the colloid away from the tab, thus preventing the electrode body from being in the area on the side of the colloid away from the tab. When the battery cell is working, the spacing between the electrodes increases, further reducing the lithium plating phenomenon of the battery cell.

[0011] In some embodiments, the colloid is coated on the surface of the insulating film.

[0012] In the above scheme, by pre-coating the colloid onto the surface of the insulating film to form a whole, and then fitting it onto the outer periphery of the electrode body, the process steps are simplified and the preparation efficiency of the battery cell is improved.

[0013] In some embodiments, the insulating film includes a first surface and a second surface disposed opposite to each other, the first surface facing the electrode assembly and the second surface facing the housing, both the first surface and the second surface being coated with the colloid.

[0014] In the above scheme, by coating the first and second surfaces of the insulating film with colloid, the binding force on the electrode body can be further improved, thereby further reducing the lithium plating phenomenon of the battery cell.

[0015] In some embodiments, the colloid is an adhesive tape wrapped around the outer periphery of the electrode body.

[0016] In the above scheme, by setting the colloid as a tape wrapped around the outer periphery of the electrode body, the area of ​​the electrode body near the tab can be bound more firmly, further reducing lithium plating.

[0017] In some embodiments, the height of the insulating film is H1, and the height of the electrode assembly is H2, wherein H1 and H2 satisfy: 0.6≤H1 / H2≤1.

[0018] In the above scheme, by limiting the height ratio of the insulating film to the electrode assembly, the insulation and binding effects can be guaranteed to a certain extent.

[0019] In some embodiments, H1 and H2 satisfy: 0.6 ≤ H1 / H2 ≤ 0.8.

[0020] In the above scheme, by further limiting the height ratio of the insulating film to the electrode assembly, space can be left for the colloid to be set, thus saving the material of the insulating film.

[0021] In some embodiments, the insulating film comprises a heat-shrinkable material.

[0022] In the above scheme, the insulating film shrinks during the hot pressing stage of the battery cell. After shrinkage, the insulating film provides a stronger binding force to the electrode assembly. Therefore, only a thin insulating film is needed to provide a strong binding force, without the need for a thick insulating film, which can increase the energy density of the battery cell.

[0023] In some embodiments, the insulating film is made of polyethylene and polyvinyl chloride.

[0024] In the above scheme, polyethylene and polyvinyl chloride have excellent insulation and heat shrinkage properties, which can improve the insulation and binding effect of the insulating film.

[0025] In some embodiments, the battery cell further includes an end cap, the housing has an opening, and the end cap is disposed at the opening of the housing; the end cap includes a cover body and an insulating member, the insulating member is disposed on the side of the cover body facing the electrode assembly, and the colloid is connected to the insulating member.

[0026] In the above solution, by connecting the colloid with the insulating component, the stability of the battery cell can be enhanced, and the heat of the electrode assembly can be transferred to the outside through the end cap.

[0027] In some embodiments, the colloid material includes a thermally conductive material, which can improve the heat dissipation effect of the battery cell.

[0028] In some embodiments, the thickness of the colloid is greater than the thickness of the insulating film.

[0029] In the above scheme, the colloid can more easily come into contact with the shell along the thickness direction of the shell, thereby making it easier for the heat generated by the tab to be carried away by the shell.

[0030] Secondly, this application also provides a method for preparing a battery cell, which is used to prepare a battery cell according to any of the above embodiments. The preparation method includes the following steps: applying an insulating film to the outer periphery of the electrode body; hot-pressing the electrode assembly; and wrapping a colloid around the outer periphery of the electrode body.

[0031] In the above scheme, the insulating film and the colloid are separate, independent components. The insulating film is first wrapped around the outer periphery of the electrode body, and then the colloid is wrapped around it after hot pressing. By setting the colloid as an adhesive tape wrapped around the outer periphery of the electrode body, the area of ​​the electrode body near the tab can be more firmly bound, reducing lithium plating at the head of the electrode body. The insulating film can also exert a certain binding force on the electrode body, reducing lithium plating in the battery cells.

[0032] In addition, this application also provides a method for preparing a battery cell, which is used to prepare a battery cell according to any of the above embodiments. The preparation method includes the following steps: coating a colloid on the surface of an insulating film; covering the insulating film on the outer periphery of the electrode body; and hot-pressing the electrode assembly.

[0033] In the above-described scheme, the colloid coated on the surface of the insulating film can more firmly bind the area of ​​the electrode body near the tab, reducing lithium plating at the electrode head. Furthermore, the insulating film also exerts a certain binding force on the electrode body, reducing lithium plating in the battery cell. Moreover, in this embodiment, the colloid is pre-coated onto the surface of the insulating film to form a whole, which is then fitted onto the outer periphery of the electrode body. This simplifies the process steps and improves the preparation efficiency of the battery cell.

[0034] Thirdly, embodiments of this application provide a battery device including a battery cell of any of the above embodiments.

[0035] Fourthly, embodiments of this application also provide an electrical device, including a battery device according to any of the above embodiments, the battery device being used to provide electrical energy.

[0036] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 is a schematic diagram of the vehicle structure according to some embodiments of this application;

[0039] Figure 2 is an exploded view of a battery device according to some embodiments of this application;

[0040] Figure 3 is a schematic diagram of the structure of a battery module according to some embodiments of this application;

[0041] Figure 4 is an exploded structural diagram of a battery cell according to some embodiments of this application;

[0042] Figure 5 is an exploded structural diagram of a battery cell according to some embodiments of this application;

[0043] Figure 6 is an exploded structural diagram of a battery cell according to some other embodiments of this application;

[0044] Figure 7 is a schematic diagram of insulating films and colloids according to some embodiments of this application;

[0045] Figure 8 is a partially exploded structural diagram of a battery cell according to some embodiments of this application;

[0046] Figure 9 is a partial cross-sectional schematic diagram of the insulating film and colloid in some embodiments of this application.

[0047] Explanation of reference numerals in the attached figures:

[0048] 1000, Vehicle; 100, Battery unit; 200, Controller; 300, Motor; 10, Top cover; 30, Housing; 400, Battery module; 20, Battery cell; 22, Housing; 21, End cap; 211, Cover; 212, Insulator; 23, Electrode assembly; 231, Tab; 232, Electrode body; 24, Insulating film; 241, First opening; 242, Second opening; 243, First surface; 244, Second surface; 25, Colloid; 26, Adapter component. Detailed Implementation

[0049] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0050] In the description of this application, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationships, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the allowable tolerance range. "Parallel" is not parallel in the strict sense, but within the allowable tolerance range.

[0051] 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.

[0052] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. It should also be noted in the description of this application that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0053] In this application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, etc., and the embodiments of this application are not limited thereto. The battery cell may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited thereto. Battery cells are generally classified into three types according to their packaging method: cylindrical battery cells, cuboid / square battery cells, and pouch battery cells, and the embodiments of this application are not limited thereto.

[0054] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0055] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells into a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0056] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0057] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0058] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[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, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0060] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0061] Please refer to Figure 1, which is a schematic diagram of the vehicle structure provided in some embodiments of this application. The vehicle 1000 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. A battery device 100 is installed inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during startup, navigation, and driving.

[0062] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0063] Please refer to Figure 2, which is an exploded view of the device provided in some embodiments of this application. The battery device 100 includes a battery housing and a battery cell 20. In some embodiments, the battery housing may include a top cover 10 and a housing 30, with the top cover 10 and the housing 30 covering each other, and the top cover 10 and the housing 30 together defining a receiving cavity for accommodating the battery cell 20. The housing 30 may be a hollow structure with one end open, and the top cover 10 may be a plate-like structure, with the top cover 10 covering the open side of the housing 30 so that the top cover 10 and the housing 30 together define the receiving cavity; the top cover 10 and the housing 30 may also be hollow structures with one side open, with the open side of the top cover 10 covering the open side of the housing 30. Of course, the battery housing formed by the top cover 10 and the housing 30 may be of various shapes, such as a cylinder, a cuboid, etc.

[0064] Figure 3 is a schematic diagram of the structure of a battery module according to some embodiments of this application. In the battery device 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 20 are connected in both series and parallel. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the whole formed by the multiple battery cells 20 is housed in a housing. Of course, the battery device 100 can also be in the form of multiple battery cells 20 first connected in series, parallel, or in a mixed manner to form a battery module 400, and then multiple battery modules 400 are connected in series, parallel, or in a mixed manner to form a whole and housed in a housing. The battery device 100 may also include other structures. For example, the battery device 100 may also include a busbar component for realizing the electrical connection between multiple battery cells 20.

[0065] Each battery cell 20 can be a secondary battery cell or a primary battery cell; it can also be a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, but is not limited to these. The battery cell 20 can be cylindrical, flat, cuboid, or other shapes.

[0066] End cap 21 refers to a component that covers the opening of housing 22 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 21 can be adapted to the shape of housing 22 to fit it. Optionally, end cap 21 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 21 is not easily deformed under pressure and impact, allowing battery cell 20 to have higher structural strength and improved safety performance. Functional components such as electrode terminals 26 can be provided on end cap 21. Electrode terminals 26 can be used for electrical connection with electrode assembly 23 to output or input electrical energy to battery cell 20. In some embodiments, end cap 21 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of battery cell 20 reaches a threshold. The material of end cap 21 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 element may be provided on the inner side of the end cap 21. The insulating element can be used to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. For example, the insulating element may be made of plastic, rubber, etc.

[0067] During recharging of a lithium-ion battery, lithium ions are extracted from the positive electrode and inserted into the negative electrode. However, some abnormal situations may occur, such as insufficient space for lithium insertion in the negative electrode, excessive resistance to lithium ion insertion into the negative electrode, or lithium ions being extracted from the positive electrode too quickly. If the extracted lithium ions cannot be inserted into the negative electrode in equal quantities, they can only gain electrons on the surface of the negative electrode, forming silvery-white metallic lithium—this is lithium plating. In the early stages of a single battery cycle, the electrode spacing increases due to a period of free cycling, thus increasing the risk of lithium plating. At the head of the electrode assembly (near the tabs), the stress generated by the tabs increases the spacing between the electrode heads, leading to a higher risk of lithium plating near the tabs in the later stages of a single battery cycle.

[0068] To address the aforementioned technical problems, this application provides a battery cell comprising a housing, an electrode assembly, and a gel. The electrode assembly is disposed within the housing and includes an electrode body and a tab disposed on one side of the electrode body. The gel is disposed on the outer periphery of the electrode body and is located near the tab on the electrode body.

[0069] In the above scheme, a gel is provided on the outer periphery of the electrode body near the tab. The gel binds the head of the electrode body (i.e., the position near the tab), which can reduce the distance between the electrode heads, thereby reducing lithium plating at the electrode assembly head when the battery cell is working and improving safety.

[0070] Figure 5 is an exploded structural diagram of a battery cell according to some embodiments of this application; Figure 6 is an exploded structural diagram of a battery cell according to other embodiments of this application.

[0071] Referring to Figures 5 and 6, in a first aspect, embodiments of this application provide a battery cell 20, which includes a housing 22, an electrode assembly 23, and a gel 25. The electrode assembly 23 is disposed within the housing 22 and includes an electrode body 232 and a tab 231 disposed on one side of the electrode body 232. The gel 25 is disposed on the outer periphery of the electrode body 232 and is located on the electrode body 232 near the tab 231.

[0072] It should be noted that "colloid 25 is located on the electrode body 232 near the tab 231" means that the colloidal 25 is disposed on the outer periphery of the head (end) of the electrode body 232 corresponding to the tab 231. For example, the tab 231 is disposed at the end of the electrode body 232. The battery body 232 includes a first end and a second end of the battery cell 20 disposed opposite each other in the height direction. The tab 231 can be disposed at either the first end or the second end, or the positive tab can be disposed at the first end and the negative tab at the second end. If both tabs 231 are disposed at the first end, then the colloidal 25 is also disposed on the outer periphery of the first end; if the tab 231 is disposed at the second end, then the colloidal 25 is also disposed on the outer periphery of the second end; if one tab 231 is disposed at the first end and the other tab 231 is disposed at the second end, then the colloidal 25 can be disposed on the outer periphery of both the first and second ends.

[0073] As shown in Figure 5, the colloid 25 can be coated or bonded to the surface of the insulating film 24, forming a single unit with the insulating film 24. Alternatively, as shown in Figure 6, the colloid 25 can be a separate tape wrapped around the head of the electrode body 232 (i.e., near the tab 231). The colloid 25 is arranged around the outer periphery of the upper end of the electrode body 232. The upper surface of the colloid 25 can be flush with or lower than the upper surface of the tab 231. The colloid 25 can also be connected to the insulating part 212 of the end cap 21.

[0074] In the above scheme, a colloid 25 is provided on the outer periphery of the electrode body 232 near the tab 231. The head of the electrode body 232 (i.e., near the tab 231) is bound by the colloid 25, which can reduce the distance between the electrode heads, thereby reducing the lithium plating phenomenon at the head of the electrode assembly 23 when the battery cell 20 is working and improving safety.

[0075] In some embodiments, the colloid 25 is continuously disposed around the outer periphery of the electrode body 232.

[0076] In other words, the colloid 25 wraps around the outer periphery of the electrode body 232 in a 360-degree direction. The colloid 25 can exert a binding force on the electrode body 232 in all directions, which can further reduce the lithium plating phenomenon at the head of the electrode assembly 23.

[0077] In some embodiments, the battery cell 20 further includes an insulating film 24 disposed on the outer periphery of the electrode body 232, the insulating film 24 being connected to the colloid 25, and at least a portion of the insulating film 24 being disposed on the side of the colloid 25 away from the tab 231.

[0078] The size and shape of the insulating film 24 can be matched with those of the electrode body 232, so that the insulating film 24 can fit and cover the outer periphery of the electrode assembly 23.

[0079] The insulating film 24 may have a first opening 241 and a second opening 242 disposed opposite to each other along the height direction of the battery cell 20, with the first opening 241 facing the tab 231. The second opening 242 may be flush with the lower end of the electrode assembly 23, and the first opening 241 may be flush with or lower than the tab 231. For example, the first opening 241 of the insulating film 24 may be located in the upper half of the electrode body 232, or the height of the insulating film 24 may be the same as the height of the electrode body 232.

[0080] The insulating film 24 can be made of materials such as polyethylene and polyvinyl chloride, and has heat-shrinkable properties. Alternatively, the insulating film 24 can also be made of materials such as polyester film and ceramic-coated film.

[0081] First, the insulating film 24 can be placed around the outer periphery of the electrode body 232, and then the electrode assembly 23 can be hot-pressed. If the insulating film 24 is a heat-shrinkable film, it will shrink during the hot-pressing stage, resulting in a greater binding force on the electrode assembly 23. Then, the battery cell 20 can be softly connected. If the adhesive 25 is a tape, it can be fixed to the edge of the insulating film 24 and wrapped around the end of the electrode body 232 near the tab 231, connecting the adhesive 25 to the insulating part 212 of the end cap 21.

[0082] Alternatively, the colloid 25 can be coated or bonded to the surface of the upper region of the insulating film 24 first, and then the insulating film 24 can be placed around the outer periphery of the electrode body 232 as a whole, and then the electrode assembly 23 can be hot-pressed. If the insulating film 24 is a heat-shrinkable film, the insulating film 24 will shrink during the hot-pressing stage, which will generate a greater binding force on the electrode assembly 23, and then the battery cell 20 can be softly connected.

[0083] It should be noted that hot pressing refers to shaping the electrode assembly 23 to reduce the risk of short circuits or changes in the spacing between electrodes due to misalignment of the electrode sheets and separator during the transfer of the battery cell 20. It also eliminates separator wrinkles, removes air from inside the electrode assembly 23, and ensures a tight fit between the separator and the electrode sheets, shortening the lithium-ion diffusion distance and reducing the internal resistance of the battery cell 20. The main process parameters for hot pressing of the battery cell 20 include the pressurization pressure, pressurization time, and template temperature. Hot pressing can be performed using a manual or automatic hot press. The soft connection refers to current collector welding, used to complete the welding work between the end cap 21 and the tab 231 or the adapter component 26.

[0084] In the above scheme, by wrapping the electrode body 232 with insulating film 24, the electrode assembly 23 can be constrained. Moreover, at least part of the insulating film 24 is disposed on the side of the colloid 25 away from the tab 231. Therefore, to a certain extent, the electrode body 232 is prevented from being in the area of ​​the colloid 25 away from the tab 231. When the battery cell 20 is working, the spacing between the electrodes increases, further reducing the lithium plating phenomenon of the battery cell 20.

[0085] In some embodiments, colloid 25 is coated on the surface of insulating film 24.

[0086] Specifically, the colloid 25 can be coated on the side of the insulating film 24 facing the electrode assembly 23, or on the side of the insulating film 24 facing the housing 22, or the colloid 25 can be coated on both the side of the insulating film 24 facing the electrode assembly 23 and the side facing the housing 22.

[0087] In the above scheme, by coating the colloid 25 on the surface of the insulating film 24 in advance to form a whole, and then wrapping it around the outer periphery of the electrode body 232, the process steps are simplified and the preparation efficiency of the battery cell 20 is improved.

[0088] Figure 7 is a schematic diagram of the insulating film and colloid of some embodiments of this application.

[0089] As shown in FIG7, in some embodiments, the insulating film 24 includes a first surface 243 and a second surface 244 disposed opposite to each other, the first surface 243 facing the electrode assembly 23 and the second surface 244 facing the housing 22, and both the first surface 243 and the second surface 244 are coated with the colloid 25.

[0090] In the above scheme, the colloid 25 on the second surface 244 can directly contact the housing 22. By coating both the first surface 243 and the second surface 244 of the insulating film 24 with colloid 25, the binding force on the head of the electrode body 232 can be further enhanced, and the risk of lithium plating at this location can be further reduced. In addition, when the material of colloid 25 is thermally conductive adhesive, coating both the first surface 243 and the second surface 244 of the insulating film 24 with colloid 25 allows a large amount of heat generated by the tab 231 to be transferred from the colloid 25 on the first surface 243 to the colloid 25 on the second surface 244, and then to the housing 22.

[0091] In other embodiments, the colloid 25 is an adhesive tape wrapped around the outer periphery of the electrode body 232.

[0092] In the above scheme, by setting the colloid 25 as a tape wrapped around the outer periphery of the electrode body 232, the area of ​​the electrode body 232 close to the tab 231 can be bound more firmly, further reducing the lithium plating phenomenon.

[0093] Figure 8 is a partially exploded structural diagram of a battery cell according to some embodiments of this application.

[0094] As shown in Figure 8, in some embodiments, the height of the insulating film 24 is H1, and the height of the electrode assembly 23 is H2, where H1 and H2 satisfy: 0.6≤H1 / H2≤1.

[0095] H1 / H2 can be any value between 0.6 and 1. For example, H1 / H2 can be 0.6, 0.7, 0.75, 0.8, 0.9, 1, etc.

[0096] In the above scheme, by limiting the height ratio of the insulating film 24 to the electrode assembly 23, the insulation and binding effects can be guaranteed to a certain extent.

[0097] In some embodiments, H1 and H2 satisfy: 0.6 ≤ H1 / H2 ≤ 0.8.

[0098] H1 / H2 can be any value between 0.6 and 0.8. For example, H1 / H2 can be 0.6, 0.65, 0.71, 0.72, 0.76, 0.8, etc.

[0099] In the above scheme, by further limiting the height ratio of the insulating film 24 to the electrode assembly 23, space can be left for the setting of the colloid 25, saving the material of the insulating film 24.

[0100] In some embodiments, the insulating film 24 comprises a heat-shrinkable material.

[0101] The insulating film 24 is a heat-shrinkable film. For example, the insulating film 24 may include heat-shrinkable materials such as polyethylene, polyvinyl chloride, and polyester, so that the insulating film 24 can shrink when heated at a temperature greater than or equal to 50°C.

[0102] In the above scheme, the insulating film 24 will shrink during the hot pressing stage of the battery cell 20. After shrinkage, the insulating film 24 provides a stronger binding force to the electrode assembly 23. Therefore, only a thin insulating film 24 is needed to provide a strong binding force, without the need to wrap a thick insulating film 24, which can increase the energy density of the battery cell 20.

[0103] In some embodiments, the insulating film 24 is made of polyethylene and polyvinyl chloride.

[0104] Polyethylene has a low dielectric constant and dielectric loss, resulting in good insulation properties. Furthermore, polyethylene exhibits good flexibility and impact resistance, enabling it to withstand mechanical stress without easily cracking or tearing.

[0105] Polyvinyl chloride (PVC) possesses high hardness, strength, and abrasion resistance, providing effective physical protection and reducing wear on electrode assembly 23. Furthermore, PVC exhibits good heat shrinkage properties, easily shrinking upon heating at a relatively rapid rate. Additionally, PVC possesses a degree of self-extinguishing property upon contact with fire, making it difficult for it to continue burning after initial combustion.

[0106] In the above scheme, polyethylene and polyvinyl chloride have excellent insulation and heat shrinkage properties, which can improve the insulation and binding effect of the insulating film 24.

[0107] In some embodiments, the battery cell 20 further includes an end cap 21, the housing 22 has an opening, and the end cap 21 is disposed at the opening of the housing 22; the end cap 21 includes a cover body 211 and an insulating member 212, the insulating member 212 is disposed on the side of the cover body 211 facing the electrode assembly 23, and the colloid 25 is connected to the insulating member 212.

[0108] Because the colloid 25 has adhesive properties, it can be directly bonded and fixed to the insulating component 212 after the battery cell 20 is softly connected.

[0109] In the above solution, by connecting the colloid 25 to the insulating component 212, the stability of the battery cell 20 can be enhanced, and the heat of the electrode assembly 23 can be transferred to the outside through the end cap 21.

[0110] In some embodiments, the material of colloid 25 includes a thermally conductive material.

[0111] The material of colloid 25 can be silicone, epoxy resin, acrylate, polyurethane, etc.

[0112] Because the electrode body 232 has tabs 231 at its head, it has a high current density and high internal resistance, resulting in significant heat generation over the same period. Conventional water cooling methods cannot directly dissipate the heat generated by the tabs 231. The colloid 25 material in this embodiment includes a thermally conductive material, allowing the heat generated by the tabs 231 to be transferred to the outside.

[0113] In the above scheme, by selecting thermally conductive adhesive as the material for colloid 25, the heat dissipation effect of the battery cell 20 can be improved.

[0114] Figure 9 is a partial cross-sectional schematic diagram of the insulating film and colloid in some embodiments of this application.

[0115] As shown in Figure 9, in some embodiments, the thickness D1 of the colloid 25 is greater than the thickness D2 of the insulating film 24.

[0116] When the colloid 25 is a tape wrapped around the outer periphery of the electrode body 232, setting the thickness D1 of the colloid 25 to be greater than the thickness D2 of the insulating film 24 can, to a certain extent, ensure that the outer periphery of the electrode assembly 23 head is wrapped with a thickness greater than the thickness of the lower area, so that the colloid 25 can come into contact with the casing 22 when the battery cell 20 is working.

[0117] In the above scheme, the colloid 25 can more easily come into contact with the shell 22 along the thickness direction of the shell 22, thereby making it easier for the heat generated by the tab 231 to be carried away by the shell 22.

[0118] Secondly, this application also provides a method for preparing a battery cell 20, which is used to prepare the battery cell 20 of any of the above embodiments. The preparation method includes the following steps: applying an insulating film 24 to the outer periphery of an electrode assembly 23; hot-pressing the electrode assembly 23; and wrapping a colloid 25 around the outer periphery of the electrode assembly 23.

[0119] In the above scheme, the insulating film 24 and the colloid 25 are separate independent components. The insulating film 24 is first wrapped around the outer periphery of the electrode body 232, and then the colloid 25 is wrapped around it after hot pressing. By setting the colloid 25 as an adhesive tape wrapped around the outer periphery of the electrode body 232, the area of ​​the electrode body 232 near the tab 231 can be more firmly bound, reducing the lithium plating phenomenon at the head of the electrode body 232. In addition, the insulating film 24 can also exert a certain binding force on the electrode body 232, reducing the lithium plating phenomenon of the battery cell 20.

[0120] In addition, this application embodiment also provides a method for preparing a battery cell 20, which is used to prepare the battery cell 20 of any of the above embodiments. The preparation method includes the following steps: coating the surface of the insulating film 24 with colloid 25; covering the outer periphery of the electrode assembly 23 with the insulating film 24; and hot-pressing the electrode assembly 23.

[0121] In the above scheme, the colloid 25 coated on the surface of the insulating film 24 can more firmly bind the area of ​​the electrode body 232 near the tab 231, reducing lithium plating at the head of the electrode body 232. The insulating film 24 also exerts a certain binding force on the electrode body 232, reducing lithium plating in the battery cell 20. Furthermore, in this embodiment, the colloid 25 is pre-coated onto the surface of the insulating film 24 to form a whole, and then fitted onto the outer periphery of the electrode body 232. This simplifies the process steps and improves the preparation efficiency of the battery cell 20.

[0122] Thirdly, embodiments of this application provide a battery device 100, including a battery cell 20 of any of the above embodiments.

[0123] Fourthly, embodiments of this application also provide an electrical device, including a battery device 100 according to any of the above embodiments, the battery device 100 being used to provide electrical energy.

[0124] According to some embodiments of this application, a battery cell 20 is provided. The battery cell 20 includes a housing 22, an electrode assembly 23, and a gel 25. The electrode assembly 23 is disposed within the housing 22 and includes an electrode body 232 and a tab 231 disposed on one side of the electrode body 232. The gel 25 is disposed on the outer periphery of the electrode body 232, and the gel 25 is located on the electrode body 232 near the tab 231. The battery cell 20 also includes an insulating film 24, which is disposed on the outer periphery of the electrode body 232 and connected to the gel 25. At least a portion of the insulating film 24 is disposed on the side of the gel 25 away from the tab 231. The insulating film 24 is configured to shrink upon heating at a temperature greater than or equal to 50°C. Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: case; An electrode assembly is disposed within the housing, the electrode assembly comprising an electrode body and a tab disposed on one side of the electrode body; A colloid is disposed on the outer periphery of the electrode body, and the colloid is located on the electrode body near the tab.

2. The battery cell according to claim 1, characterized in that, The colloid is continuously arranged around the outer periphery of the electrode body.

3. The battery cell according to claim 1, characterized in that, The battery cell also includes an insulating film disposed on the outer periphery of the electrode body, the insulating film being connected to the colloid, and at least a portion of the insulating film being disposed on the side of the colloid away from the tab.

4. The battery cell according to claim 3, characterized in that, The colloid is coated on the surface of the insulating film.

5. The battery cell according to claim 4, characterized in that, The insulating film includes a first surface and a second surface disposed opposite to each other, the first surface facing the electrode assembly and the second surface facing the housing, and both the first surface and the second surface are coated with the colloid.

6. The battery cell according to claim 3, characterized in that, The colloid is a tape wrapped around the outer periphery of the electrode body.

7. The battery cell according to claim 6, characterized in that, The height of the insulating film is H1, and the height of the electrode assembly is H2. H1 and H2 satisfy: 0.6≤H1 / H2≤1.

8. The battery cell according to claim 7, characterized in that, H1 and H2 satisfy: 0.6≤H1 / H2≤0.

8.

9. The battery cell according to any one of claims 2-8, characterized in that, The insulating film includes a heat-shrinkable material.

10. The battery cell according to claim 9, characterized in that, The insulating film is made of materials including polyethylene and polyvinyl chloride.

11. The battery cell according to any one of claims 1-10, characterized in that, The battery cell also includes an end cap, the housing has an opening, and the end cap is disposed at the opening of the housing; the end cap includes a cover body and an insulating member, the insulating member is disposed on the side of the cover body facing the electrode assembly, and the colloid is connected to the insulating member.

12. The battery cell according to any one of claims 1-11, characterized in that, The colloid is made of thermally conductive materials.

13. The battery cell according to claim 12, characterized in that, The thickness of the colloid is greater than the thickness of the insulating film.

14. A method for preparing a single battery cell, characterized in that, The method for preparing a battery cell according to any one of claims 1-13 includes the following steps: applying an insulating film to the outer periphery of the electrode body; hot-pressing the electrode assembly; and wrapping the colloid around the outer periphery of the electrode body.

15. A method for preparing a single battery cell, characterized in that, The method for preparing a battery cell according to any one of claims 1-13 includes the following steps: coating the colloid on the surface of an insulating film; covering the insulating film on the outer periphery of the electrode body; and hot-pressing the electrode assembly.

16. A battery device, characterized in that, It includes the battery cell according to any one of claims 1-13, or the battery cell prepared by the preparation method according to claim 14 or 15.

17. An electrical device, characterized in that, Includes the battery device according to claim 16, the battery device being used to provide electrical energy.

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