Battery cell, battery, and device

Abstract

A battery cell (22), a battery (2), and a device. An insulating patch (224) is used to cover an electrode assembly (223). The side of the insulating patch (224) has a heat-melting region (2241) and a non-heat-melting region (2242). The heat-melting region (2241) is used to heat-melt with a lower plastic (2212), and the non-heat-melting region (2242) is lower than the heat-melting region (2241). After the electrode assembly (223) covered with insulating patch (224) is installed onto the housing (222), and the heat-melting area (2241) of the insulating patch (224) is heat-melted onto the lower plastic (2212) of the top cover assembly (221), and then the top cover (2211) and the housing (222) are welded together by laser, since the non-heat-melting area (2242) of the insulating patch (224) is lower than the heat-melting area (2241), the non-heat-melting area (2242) of the insulating patch (224) can be prevented from interfering with the welding position of the top cover (2211) and the housing (222). Thus, the top cover (2211) and the housing (222) will not have a problem of false welding during welding, which helps to improve the sealing performance of the top cover (2211) and the housing (222), avoids leakage of the electrode assembly (223), and further improves the safety of the electrode assembly (223).

Description

Technical Field

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

[0002] Currently, with the trend of vehicle electrification, the volume of electric vehicles in my country is growing rapidly. As electric vehicles develop, batteries have become crucial for the sustainable development of the automotive industry. For electric vehicles, battery production technology is a vital factor in their development. During battery production, when installing bare cells into the space formed by the casing and cover, insulating patches need to be wrapped around the bare cells to achieve insulation between the cells and the casing.

[0003] However, in the existing technology, due to the interference of the insulating patch, the welding of the shell and the top cover by laser can lead to the problem of poor welding, which in turn can cause poor sealing of the shell and the top cover, and even cause leakage of the battery cells inside the shell and the top cover, affecting the safety of the battery cells. Summary of the Invention

[0004] In view of the above problems, this application provides a battery cell, a battery, and a device. The non-melting area of ​​the insulating patch does not interfere with the welding position of the top cover and the housing, so that the top cover and the housing will not have a poor weld during welding, which helps to improve the sealing performance of the top cover and the housing, avoids leakage of the electrode assembly, and improves the safety of the electrode assembly.

[0005] In a first aspect, this application provides an insulating patch for covering an electrode assembly. The side of the insulating patch has a heat-melting region and a non-heat-melting region. The heat-melting region is used to heat-melt with the lower plastic, and the non-heat-melting region is lower than the heat-melting region.

[0006] In the technical solution of this application embodiment, after the electrode assembly covered with insulating patches is installed onto the housing, and the hot-melt area of ​​the insulating patch is hot-melted to the lower plastic of the top cover assembly, the top cover and the housing are then welded together by laser. Because the non-hot-melt area of ​​the insulating patch is lower than the hot-melt area, interference between the non-hot-melt area of ​​the insulating patch and the welding position of the top cover and the housing can be avoided. Therefore, the problem of incomplete welding does not occur when the top cover and the housing are welded, which helps to improve the sealing performance of the top cover and the housing, prevents leakage of the electrode assembly, and further improves the safety of the electrode assembly.

[0007] In some embodiments, the insulating patch forms a rectangular opening when covering the electrode assembly. The sidewall of the insulating patch corresponding to the long side of the rectangle has multiple heat-fused regions. Adjacent heat-fused regions form a groove, such that non-heat-fused regions are lower than the heat-fused regions.

[0008] In this embodiment, a groove is formed between adjacent hot-melt areas so that the non-hot-melt area is lower than the hot-melt area. In addition, multiple hot-melt areas are set on the long side of the opening of the insulating patch, which can better match the hot-melt position of the lower plastic, so that the hot-melt area of ​​the insulating patch and the hot-melt position of the lower plastic are better fused together, thereby increasing the connection strength between the insulating patch and the lower plastic.

[0009] In some embodiments, the groove is square or arc-shaped. Designing the groove to be square or arc-shaped makes it easier to form grooves between adjacent hot-melt areas, facilitating processing.

[0010] In some embodiments, the depth of the groove ranges from 2 mm to 5 mm. This embodiment can further avoid the phenomenon that the non-thermal-melting area of ​​the insulating patch may interfere with the welding position of the top cover and the housing due to the groove depth being too small (e.g., less than 2 mm). This embodiment can also avoid the phenomenon that when the insulating patch covers the electrode assembly, some of the electrode assembly may be exposed and in contact with the housing due to the groove depth being too large (e.g., greater than 5 mm).

[0011] In some embodiments, the sidewall of the insulating patch corresponding to the shorter side of the rectangle has a heat-melting area. This design allows the insulating patch to better match the heat-melting position of the underlying plastic, enabling the heat-melting area of ​​the insulating patch to fuse more effectively with the heat-melting position of the underlying plastic.

[0012] In some embodiments, the orthographic projection of the insulating patch along its thickness direction when unfolded is I-shaped, including a first portion in the middle and second and third portions at both ends of the first portion. The first portion covers the bottom surface of the electrode assembly. The second and third portions are folded toward the electrode assembly, such that the second and third portions, which do not protrude from the first portion, cover the opposite first and second sides of the electrode assembly, respectively, where the first and second sides correspond to the long sides of a rectangle. The second and third portions, which protrude from the first portion, are folded toward the electrode assembly, covering the opposite third and fourth sides of the electrode assembly, where the third and fourth sides correspond to the short sides of a rectangle.

[0013] In this embodiment, the orthographic projection of the insulating patch along the thickness direction of the insulating patch when it is unfolded is I-shaped, which makes the wrapping method of wrapping the electrode assembly with the insulating patch simpler and can save assembly time.

[0014] In some embodiments, the second and third portions protruding from the first portion have overlapping areas when covering the third and fourth sides, and the overlapping areas form a heat-fused region. By forming a heat-fused region through the aforementioned overlapping areas, the strength of the heat-fused region can be increased.

[0015] In some embodiments, beveled angles are provided at the corners of the second and third parts away from the first part. By providing beveled angles, it is possible to prevent the overlapping areas of the second and third parts from interfering with the welding positions of the top cover and the housing due to warping.

[0016] In some embodiments, the bevel angle ranges from 4 degrees to 20 degrees. This embodiment can further avoid the phenomenon that the non-thermal-melting area of ​​the insulating patch may interfere with the welding position of the top cover and the housing due to an excessively small bevel angle (e.g., less than 4 degrees). This embodiment can also avoid the phenomenon that when the insulating patch covers the electrode assembly, some of the electrode assembly may be exposed and in contact with the housing due to an excessively large bevel angle (e.g., greater than 20 degrees).

[0017] In some embodiments, the beveled corner is triangular or trapezoidal in shape. Designing the beveled corner as triangular or trapezoidal allows the overlapping area formed by the second and third parts after covering the electrode assembly to better match the lower plastic hot-melt position, and makes the processing of the beveled corner more convenient.

[0018] In some embodiments, the battery cell further includes an adapter located between the top cover and the electrode assembly, wherein the terminal on the top cover is connected to the tab of the electrode assembly via the adapter. This embodiment allows the terminal on the top cover and the tab of the electrode assembly to be connected via the adapter.

[0019] Secondly, this application also provides a battery comprising a plurality of battery cells as described in any of the above embodiments.

[0020] Thirdly, this application also provides a device that uses a battery as a power source, wherein the battery in this embodiment is the same as any of the batteries described in the above embodiments. Attached Figure Description

[0021] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 The diagram shows the structural features of a vehicle provided in some embodiments of this application.

[0022] Figure 2 This is an exploded schematic diagram of a battery provided for some embodiments of this application.

[0023] Figure 3 This is an exploded schematic diagram of a battery cell provided in some embodiments of this application.

[0024] Figure 4A front view of a battery cell provided for some embodiments of this application.

[0025] Figure 5 The diagram shows the structure of a single battery cell provided in some embodiments of this application.

[0026] Figure 6 This is a schematic diagram of the structure of the insulating patch when covering the electrode assembly provided in some embodiments of this application.

[0027] Figure 7 This diagram illustrates the positional relationship between the top cover assembly and the insulating patch provided in some embodiments of this application.

[0028] Figure 8 This is an unfolded view of an insulating patch provided in some embodiments of this application.

[0029] Figure 9 This is an unfolded view of another insulating patch provided for some embodiments of this application.

[0030] The reference numerals in the detailed embodiments are as follows: 1-Vehicle; 2-Battery; 3-Controller; 4-Motor; 21-Box; 22-Battery cell; 211-First box assembly; 212-Second box assembly; 213-Accommodation space; 221-Top cover assembly; 222-Shell; 223-Electrode assembly; 224-Insulating patch; 225-Adapter; 2211-Top cover; 2212-Lower plastic; 2241-Hot melt area; 2242-Non-hot melt area; 2243-Arc-shaped groove; 2244-Square groove; H-Depth of groove; 2245-First part; 2246-Second part; 2247-Third part; R-Beveled angle; 5-; 6-; 7-. Detailed Implementation

[0031] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein 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 specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0033] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0034] In this document, the term "embodiment" means that a particular 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 separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0035] In the description of the embodiments 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, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0036] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0037] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0038] Currently, the application of power batteries is becoming increasingly widespread, judging from market trends. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the development of electric vehicles, military equipment, and aerospace, batteries have become crucial for the sustainable development of the automotive industry. For electric vehicles, military equipment, and aerospace devices, battery technology is a vital factor in their development.

[0039] The inventors have noticed that during battery manufacturing, when installing bare cells into the space formed by the casing and top cover, it is necessary to wrap insulating patches around the bare cells to achieve insulation between the bare cells and the casing. However, due to interference from the insulating patches, incomplete soldering can occur when the casing and top cover are welded together using lasers. This can lead to poor sealing between the casing and top cover, and even leakage of the cells inside the casing and top cover, affecting the safety of the cells.

[0040] Based on the above considerations, and in order to solve the aforementioned problems, the applicant, after in-depth research, designed an insulating patch, a battery cell, a battery, and a device. The non-melting area of ​​the insulating patch does not interfere with the welding position of the top cover and the housing, preventing incomplete welding during the welding process. This helps improve the sealing performance of the top cover and the housing, avoids leakage of the electrode assembly, and enhances the safety of the electrode assembly.

[0041] The battery mentioned in this application is composed of individual battery cells. These batteries may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application are not limited to these. Such batteries can be applied to various electrical devices.

[0042] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical devices.

[0043] According to some embodiments of this application, this embodiment provides a device that uses a battery as a power source. This device can be, for example, but not limited to, vehicles, ships, or aircraft. Figure 1 As shown, Figure 1 This is a schematic diagram of the structure of a vehicle provided in some embodiments of this application. A battery 2 is disposed inside the vehicle 1, and the battery 2 may be located at the bottom, front, or rear of the vehicle 1. The battery 2 can be used to power the vehicle 1; for example, the battery 2 can serve as the operating power source for the vehicle 1.

[0044] Vehicle 1 may also include controller 3 and motor 4. Controller 3 is used to control battery 2 to supply power to motor 4, for example, for the power needs of vehicle 1 during start-up, navigation and driving.

[0045] In some embodiments of this application, the battery 2 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.

[0046] According to some embodiments of this application, this embodiment provides a battery. Figure 2 This is an exploded schematic diagram of battery 2 provided in some embodiments of this application. For example... Figure 2 As shown, the battery 2 includes a housing 21 and battery cells 22, with the battery cells 22 housed within the housing 21. The battery cells 22 can be formed from multiple battery modules. The housing 21 houses the battery cells 22 and can have various structures. In some embodiments, the housing 21 may include a first housing assembly 211 and a second housing assembly 212, which overlap each other, and together define a housing space 213 for accommodating the battery cells 22. The second housing assembly 212 can be a hollow structure with one open end, and the first housing assembly 211 is a plate-like structure. The first housing assembly 211 covers the open side of the second housing assembly 212 to form a housing 21 with a receiving space 213. Alternatively, both the first housing assembly 211 and the second housing assembly 212 can be hollow structures with one open side, with the open side of the first housing assembly 211 covering the open side of the second housing assembly 212 to form a housing 21 with a receiving space 213. Of course, the first housing assembly 211 and the second housing assembly 212 can be of various shapes, such as cylinders, cuboids, etc.

[0047] According to some embodiments of this application, this embodiment provides a battery cell, such as Figures 3 to 5 As shown, Figure 3 This is an exploded view of a single battery cell provided in some embodiments of this application. Figure 4 This is a front view of a battery cell provided in some embodiments of this application. Figure 5The diagram shows the structure of a single battery cell provided in some embodiments of this application.

[0048] like Figures 3 to 5 As shown, the battery cell includes: a top cover assembly 221, a housing 222, an electrode assembly 223, and an insulating patch 224. The top cover assembly 221 includes a top cover 2211 and a lower plastic piece 2212 bonded to the top cover 2211. The housing 222 and the top cover assembly 221 form a closed space. The electrode assembly 223 is located within this closed space. The insulating patch 224 covers the electrode assembly 223 within the closed space and is heat-fused to the lower plastic piece 2212 via a heat-fusion area. The terminals on the top cover 2211 are connected to the tabs of the electrode assembly 223.

[0049] The housing 222 and the top cover assembly 221 form an outer shell, which can be of various shapes, such as a cylinder or a cuboid. The shape of the outer shell can be determined according to the specific shape of the electrode assembly 223. For example, if the electrode assembly 223 is a cylindrical structure, a cylindrical outer shell can be selected; if the electrode assembly 223 is a cuboid structure, a cuboid outer shell can be selected.

[0050] The aforementioned battery cell also includes an electrolyte. The housing 222 is capable of containing the electrolyte to provide a sealed space for the electrode assembly and the electrolyte.

[0051] The housing 224 may have an opening on one side, and the top cover assembly 221 may be configured as one opening that covers the housing 224. Alternatively, the housing 224 may also have an opening on both sides, and two top cover assemblies 221 may be configured, with the two top cover assemblies 221 respectively covering the two openings of the housing 224.

[0052] For example, the top cover assembly 221 is connected to the housing 224 by welding, bonding, snap-fitting or other means.

[0053] In some embodiments, reference Figure 3 The battery cell may also include a positive electrode terminal 5, a negative electrode terminal 6, and a pressure relief mechanism 7, all of which are mounted on the top cover assembly 221. The positive electrode terminal 5 and the negative electrode terminal 6 are respectively used for electrical connection to the positive and negative electrode plates to extract the electrical energy generated by the electrode assembly 223. The pressure relief mechanism 7 is used to release the internal pressure of the battery cell when the internal pressure reaches a predetermined value.

[0054] For example, the pressure relief mechanism 7 is located between the positive electrode terminal 5 and the negative electrode terminal 6. The pressure relief mechanism 7 can be a component such as an explosion-proof valve, an explosion-proof disc, a gas valve, a pressure relief valve, or a safety valve.

[0055] The electrode assembly 223 can be one or more. For example, such as... Figure 3 As shown, there are two electrode assemblies 223.

[0056] The electrode assembly includes a positive electrode, a negative electrode, and a separator. A single 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 latter coated on the surface of the current collector. The current collector includes a current-collecting section and a tab; the current-collecting section is coated with the positive active material layer, while the tab is not. Taking a lithium-ion battery as an example, the positive current collector can be made of aluminum, and the positive active material layer includes the positive active material, which 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 latter coated on the surface of the current collector. The current-collecting section includes a current-collecting section and a tab; the current-collecting section is coated with the negative active material layer, while the tab is not. The negative electrode current collector can be made of copper, and the negative electrode active material layer includes the negative electrode active material, which can be carbon or silicon, etc. The separator can be made of PP (polypropylene) or PE (polyethylene), etc.

[0057] According to some embodiments of this application, the battery cell further includes an adapter 225, which is located between the top cover 2211 and the electrode assembly 223. The terminal post on the top cover 2211 is connected to the tab of the electrode assembly 223 via the adapter 225. In this embodiment, the terminal post on the top cover 2211 and the tab of the electrode assembly 223 can be connected via the adapter 225.

[0058] According to some embodiments of this application, an insulating patch is provided; please refer to [link to relevant documentation]. Figure 6 , Figure 6 This is a schematic diagram of the structure of the insulating patch when covering the electrode assembly provided in some embodiments of this application. Figure 7 This is a schematic diagram showing the positional relationship between the top cover assembly 221 and the insulating patch 224.

[0059] Combination Figure 3 Insulating patch 224 is used to cover electrode assembly 223. For example... Figure 6 and Figure 7 As shown, the side of the insulating patch 224 has a heat-melting region 2241 and a non-heat-melting region 2242. The heat-melting region 2241 is used to heat-melt with the lower plastic 2212, and the non-heat-melting region 2242 is lower than the heat-melting region 2241.

[0060] For example, after the insulating patch 224 covers the electrode assembly 223, it is installed into the housing 222 together with the electrode assembly 223. When the insulating patch 224 and the electrode assembly 223 are installed into the housing 222, the contact between the housing 222 and the insulating patch 224 will cause friction on the insulating patch 224, causing the upper edge of the insulating patch 224 to be pulled upward by the frictional force. If the non-heat-melting area 2242 is higher than or flush with the heat-melting area 2241, it may cause the non-heat-melting area 2242 to be higher than the lower plastic 2212 when the lower plastic 2212 is heat-melted with the heat-melting area 2241. Furthermore, since the lower plastic 2212 is very thin, the non-heat-melting area 2242 may even extend beyond the upper surface of the lower plastic 2212 and contact part of the side edge of the top cover 2211, which may lead to a poor weld when the top cover 2211 is welded to the housing 222 using a laser.

[0061] In this application, the non-melting area 2242 is designed to be lower than the melting area 2241. This provides space for the insulating patch 224 to be pulled upward by friction when the insulating patch 224 and the electrode assembly 223 are installed into the housing 222. This avoids the non-melting area 2242 being higher than the lower plastic 2212 when the lower plastic 2212 is melted with the melting area 2241. This also avoids the occurrence of poor welding when the top cover 2211 is welded to the housing 222 using a laser.

[0062] In summary, after installing the electrode assembly 223 covered with insulating patch 224 onto the housing 222, and hot-melt area 2241 of insulating patch 225 is hot-melted to the lower plastic 2212 of top cover assembly 221, and then welding the top cover 2211 and housing 222 together using laser, the non-hot-melt area 2242 of insulating patch 224 is lower than the hot-melt area 2241. Therefore, interference between the non-hot-melt area 2242 of insulating patch 224 and the welding position of the top cover 2211 and housing 222 can be avoided. This prevents incomplete welding of the top cover 2211 and housing 222, improves the sealing performance of the top cover 2211 and housing 222, prevents leakage of the electrode assembly 223, and further enhances the safety of the electrode assembly 223.

[0063] According to some embodiments of this application, reference is made to Figure 6 The insulating patch 224 forms a rectangular opening when covering the electrode assembly. The sidewall of the insulating patch 224 corresponding to the long side of the rectangle has multiple heat-melting regions 2241. Adjacent heat-melting regions 2241 form a groove, so that the non-heat-melting region 2242 is lower than the heat-melting region 2241.

[0064] In this embodiment, a groove is formed between adjacent heat-melting areas 2241 so that the non-heat-melting area 2242 is lower than the heat-melting area 2241. Furthermore, multiple heat-melting areas 2241 are provided along the long side of the opening of the insulating patch 224. This better matches the heat-melting position of the lower plastic, allowing the heat-melting areas 2241 of the insulating patch 224 to fuse better with the heat-melting position of the lower plastic, increasing the connection strength between the insulating patch 224 and the lower plastic. It should be noted that this embodiment and the accompanying drawings illustrate this with an example of three heat-melting areas 2241 along the long side of the opening of the insulating patch 224, and do not limit the number of heat-melting areas 2241 along the long side of the opening of the insulating patch 224. In practical applications, the number of heat-melting areas 2241 along the long side of the opening of the insulating patch 224 is determined based on the heat-melting position of the lower plastic.

[0065] According to some embodiments of this application, the groove is square or arc-shaped. For example... Figure 8 As shown, Figure 8 This is an unfolded view of the insulating patch 224 according to an embodiment of this application, wherein the groove is an arc-shaped groove 2243. Designing the groove as an arc-shaped groove 2243 makes it easier to form grooves in adjacent heat-fused areas 2241, and facilitates processing.

[0066] Alternatively, in another embodiment, such as Figure 9 As shown, Figure 9 This is an unfolded view of another insulating patch 224 according to an embodiment of this application, wherein the groove is a square groove 2244. Designing the groove as a square groove 2244 makes it easier to form grooves in adjacent heat-fused areas 2241, and facilitates processing.

[0067] According to some embodiments of this application, in conjunction with Figure 6 The depth H of the groove ranges from 2mm to 5mm. For example, the depth H of the groove is 2mm, 3mm, or 5mm, etc., which will not be listed here. This embodiment can further avoid the phenomenon that the non-heat-melting area 2242 of the insulating patch 224 may interfere with the welding position of the top cover assembly and the housing due to the groove depth H being too small (e.g., less than 2mm). This embodiment can also avoid the phenomenon that when the insulating patch 224 covers the electrode assembly, part of the electrode assembly may be exposed and in contact with the housing due to the groove depth H being too large (e.g., greater than 5mm).

[0068] According to some embodiments of this application, in conjunction with Figure 6The insulating patch 224 forms a rectangular opening when covering the electrode assembly. The sidewall of the insulating patch 224 corresponding to the short side of the rectangle has a heat-fusion region 2241. Since there is typically one heat-fusion position on the lower plastic corresponding to the short side of the insulating patch 224, this design allows the insulating patch 224 to better match the heat-fusion position of the lower plastic, resulting in better heat fusion of the heat-fusion region 2241 of the insulating patch 224 with the heat-fusion position of the lower plastic.

[0069] According to some embodiments of this application, such as Figure 8 and Figure 9 As shown, when the insulating patch 224 is unfolded, its orthographic projection along the thickness direction of the insulating patch 224 is H-shaped, including a first part 2245 located in the middle and second parts 2246 and third parts 2247 located at both ends of the first part 2245. The first part 2245 is used to cover the bottom surface of the electrode assembly. The second parts 2246 and third parts 2247 are folded toward the electrode assembly, so that the second parts 2246 and third parts 2247 that do not protrude from the first part 2245 cover the opposite first side and second side of the electrode assembly, respectively, wherein the first side and the second side correspond to the long side of the aforementioned rectangle. The second parts 2246 and third parts 2247 that protrude from the first part 2245 are folded toward the electrode assembly, respectively, covering the opposite third side and fourth side of the electrode assembly, wherein the third side and the fourth side correspond to the short side of the aforementioned rectangle.

[0070] In this embodiment, the orthographic projection of the insulating patch 224 along the thickness direction of the insulating patch 224 when it is unfolded is I-shaped, which makes the wrapping method of the insulating patch 224 covering the electrode assembly simpler and can save assembly time.

[0071] According to some embodiments of this application, in conjunction with Figure 6 The second part 2246 and the third part 2247, which protrude from the first part 2245, have an overlapping area when covering the third and fourth sides, and this overlapping area forms a heat-fused region 2241. By forming the heat-fused region 2241 through the aforementioned overlapping area, the strength of the heat-fused region 2241 can be increased.

[0072] According to some embodiments of this application, reference is made to Figure 8 and Figure 9 Both the second part 2246 and the third part 2247 have beveled angles R at the corners away from the first part 2245. By setting beveled angles R, the overlapping areas of the second part 2246 and the third part 2247 can be prevented from interfering with the welding position of the top cover assembly and the housing due to warping.

[0073] According to some embodiments of this application, reference is made to Figure 8 and Figure 9The bevel angle R ranges from 4 degrees to 20 degrees. For example, 4 degrees, 8 degrees, or 20 degrees, etc., are not listed here. This embodiment can further avoid the phenomenon that the non-thermal-melting area 2242 of the insulating patch 224 might interfere with the welding position of the top cover assembly and the housing due to an excessively small bevel angle R (e.g., less than 4 degrees). This embodiment can also avoid the phenomenon that when the insulating patch 224 covers the electrode assembly, some of the electrode assembly might be exposed and in contact with the housing due to an excessively large bevel angle R (e.g., greater than 20 degrees).

[0074] According to some embodiments of this application, reference is made to Figure 8 and Figure 9 The beveled angle R is triangular or trapezoidal. Designing the beveled angle R as triangular or trapezoidal allows the overlapping area formed by the second part 2246 and the third part 2247 after covering the electrode assembly to better match the lower plastic hot melt position, and makes the processing of the beveled angle R more convenient.

[0075] According to some embodiments of this application, this application provides an insulating patch for covering electrode assemblies. For example... Figure 6 As shown, the insulating patch 224 has a heat-melting region 2241 and a non-heat-melting region 2242 on its side. The heat-melting region 2241 is used to heat-melt with the lower plastic, and the non-heat-melting region 2242 is lower than the heat-melting region 2241.

[0076] The insulating patch 224 forms a rectangular opening when covering the electrode assembly. The sidewall of the insulating patch 224 corresponding to the long side of the rectangle has multiple heat-melting regions. The sidewall of the insulating patch 224 corresponding to the short side of the rectangle has one heat-melting region. A groove is formed between adjacent heat-melting regions 224 on the sidewall of the insulating patch 224 corresponding to the long side of the rectangle, so that the non-heat-melting region 2242 is lower than the heat-melting region 2241.

[0077] like Figure 8 and Figure 9As shown, when the insulating patch 224 is unfolded, its orthographic projection along the thickness direction is I-shaped, including a first part 2245 located in the middle and second parts 2246 and third parts 2247 located at both ends of the first part 2245. The first part 2245 covers the bottom surface of the electrode assembly. The second parts 2246 and third parts 2247 are folded toward the electrode assembly, so that the second parts 2246 and third parts 2247 that do not protrude from the first part 2245 cover the opposite first and second sides of the electrode assembly, respectively, wherein the first and second sides correspond to the long sides of the aforementioned rectangle. The second parts 2246 and third parts 2247 that protrude from the first part 2245 are folded toward the electrode assembly, respectively, covering the opposite third and fourth sides of the electrode assembly, wherein the third and fourth sides correspond to the short sides of the aforementioned rectangle. The second parts 2246 and third parts 2247 that protrude from the first part 2245 have an overlapping area when covering the third and fourth sides, and this overlapping area forms a heat-fused area 2241.

[0078] In the technical solution of this application embodiment, after the electrode assembly 223 covered with insulating patch 224 is installed onto the housing 222, and the hot-melt area 2241 of the insulating patch 224 is hot-melted to the lower plastic of the top cover assembly, and then the top cover assembly and the housing are welded together by laser, since the non-hot-melt area 2242 of the insulating patch 224 is lower than the hot-melt area 2241, the non-hot-melt area 2242 of the insulating patch 224 can avoid interfering with the welding position of the top cover assembly and the housing. Therefore, the problem of incomplete welding will not occur when the top cover assembly and the housing are welded, which helps to improve the sealing performance of the top cover assembly and the housing, avoids leakage of the electrode assembly, and further improves the safety of the electrode assembly.

[0079] 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: A top cover assembly, including a top cover and a lower plastic piece fitted together with the top cover; The housing, together with the top cover assembly, forms an enclosed space; An electrode assembly is located within the enclosed space, and the electrode post on the top cover is connected to the electrode tab of the electrode assembly; An insulating patch covers the electrode assembly and is located within the enclosed space. The insulating patch has a heat-melting area and a non-heat-melting area on the side near the top cover. The heat-melting area is used to heat-melt with the lower plastic. Along the direction from the top cover to the electrode assembly, the non-heat-melting area is lower than the heat-melting area.

2. The battery cell as described in claim 1, characterized in that, The insulating patch forms a rectangular opening when it covers the electrode assembly; The sidewall of the insulating patch corresponding to the long side of the rectangle has multiple heat-melting areas; The adjacent hot-melt regions form a groove, so that the non-hot-melt regions are lower than the hot-melt regions.

3. The battery cell as described in claim 2, characterized in that, The groove is square or arc-shaped.

4. The battery cell as described in claim 2 or 3, characterized in that, The depth of the groove ranges from 2 mm to 5 mm.

5. The battery cell as described in claim 2, characterized in that, The short side of the rectangle corresponds to a heat-melting area on the sidewall of the insulating patch.

6. The battery cell as described in claim 5, characterized in that, When the insulating patch is unfolded, its orthographic projection along the thickness direction of the insulating patch is I-shaped, including a first part located in the middle and a second and a third part located at both ends of the first part; The first part is used to cover the bottom surface of the electrode assembly, and the second part and the third part are folded toward the electrode assembly respectively, so that the second part and the third part, which do not protrude from the first part, respectively cover the opposite first side and second side of the electrode assembly, wherein the first side and the second side correspond to the long side of the rectangle; The second and third portions, which protrude from the first portion, fold toward the electrode assembly, respectively, covering the opposing third and fourth sides of the electrode assembly, wherein the third and fourth sides correspond to the short sides of the rectangle.

7. The battery cell as described in claim 6, characterized in that, The second and third portions protruding from the first portion have overlapping areas when covering the third and fourth sides, and the overlapping areas form the hot-melt area.

8. The battery cell as described in claim 7, characterized in that, Both the second part and the third part have beveled corners at the corners away from the first part.

9. The battery cell as described in claim 8, characterized in that, The angle of the bevel is between 4 degrees and 20 degrees.

10. The battery cell as described in claim 8, characterized in that, The shape of the oblique angle is a triangle or a trapezoid.

11. The battery cell as described in claim 1, characterized in that, The battery cell also includes: An adapter is located between the top cover and the electrode assembly, wherein the electrode post on the top cover is connected to the tab of the electrode assembly via the adapter.

12. A battery, characterized in that, The battery comprises a plurality of battery cells as described in any one of claims 1-11.

13. A device that uses a battery as a power source, characterized in that, The battery is the battery as described in claim 12.

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