Battery monomer, battery and electric device

Abstract

The utility model discloses a battery monomer, a battery and a power utilization device. The battery cell comprises a top cover (210) with a top cover sheet (211) and a lower plastic part (230), the top cover sheet (211) is provided with at least one hot melting hole (2111), at least one hot melting column (231) is arranged on the lower plastic part (230), and the at least one hot melting column (231) is matched with the at least one hot melting hole (2111) and can be respectively aligned with the matched hot melting hole (2111). At least one hot melting hole (2111) comprises at least one inverted step on the cross section parallel to the depth direction of the hot melting hole (2111). According to the battery monomer provided by the embodiment of the invention, the connection strength between the top cover and the lower plastic part is improved, so that the structural stability and safety of the battery monomer are improved, and the service life of the battery monomer is prolonged.

Description

Technical Field

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

[0002] Power batteries are the core component of new energy vehicles and an important direction for future energy transition. To meet the requirements for battery energy density, batteries typically include one or more battery modules connected in series and / or parallel, and each battery module can include multiple battery cells connected in series and / or parallel. Therefore, batteries usually consist of multiple battery cells.

[0003] The battery cell may include a top cover. The top cover may include a top cover sheet for securing and sealing. The top cover may cooperate with a lower plastic component to achieve sealing and insulation between the top cover and the battery cell. A heat-fused post may be provided between the lower plastic component and the top cover sheet for connecting and securing the top cover and the lower plastic component. However, under high-temperature conditions, the heat-fused post between the lower plastic component and the top cover may soften, causing the lower plastic component to detach from the top cover. This can adversely affect the structural stability, safety, and lifespan of the battery cell. Utility Model Content

[0004] In view of the above problems, this application provides a battery cell, a battery, and an electrical device, wherein the connection strength between the top cover and the lower plastic part is improved, thereby improving the structural stability, safety, and service life of the battery cell.

[0005] In a first aspect, this application provides a battery cell comprising a top cover having a top cover sheet and a lower plastic part, the top cover sheet having at least one hot-melt hole and the lower plastic part having at least one hot-melt post, the at least one hot-melt post being disposed with the at least one hot-melt hole and being respectively alignable with the corresponding hot-melt hole, characterized in that the at least one hot-melt hole includes at least one inverted step on its cross section parallel to its depth direction.

[0006] Therefore, according to the technical solution of this application, the inverted steps of the hot-melt hole can increase the force-bearing area of ​​the hot-melt column in the top cover sheet, thereby improving the connection strength between the lower plastic part and the top cover. This prevents the lower plastic part from detaching from the hot-melt hole on the top cover sheet after softening due to heat, thus preventing the lower plastic part from pressing down on the bare cell's electrode and causing lithium plating and short circuits. Therefore, it can improve the structural stability, safety, and service life of the battery cell.

[0007] In some embodiments, the number of the at least one inverted step is determined by the thickness of the top cover plate. This allows the number of inverted steps to be set as needed, thereby increasing the connection strength as required.

[0008] In some embodiments, half the difference between the wider upper edge and the narrower lower edge of the inverted step constitutes the width of the step, which is in the range of 0.1 mm to 0.6 mm. This ensures that the hot-melt column can completely fill the hot-melt hole of the top cover sheet during hot-melt welding, while increasing the connection strength between the lower plastic part and the top cover.

[0009] In some embodiments, the height of the inverted step is in the range of 0.1 mm to 0.8 mm. This prevents the hot-melt column from breaking during hot melting.

[0010] In some embodiments, the inverted step has a transition fillet with a radius between 0.03 mm and 0.6 mm. This reduces stress concentration, thereby reducing or preventing breakage of the molten column during molten melting.

[0011] In some embodiments, at least one hot-melt hole includes multiple inverted steps on a cross-section parallel to its depth direction, with the cross-sectional dimension of the upper inverted step being smaller than that of the lower inverted step. This facilitates the hot-melt column completely filling each step of the hot-melt hole during hot-melt fusion.

[0012] In some embodiments, the lower plastic part is made of polybutylene terephthalate. This allows for an increase in the softening temperature of the lower plastic part without significantly increasing the cost.

[0013] In some embodiments, the lower plastic part and the hot-melt column are integrally molded. This further improves the connection strength between the top cover and the lower plastic part.

[0014] In some embodiments, the number of hot melt holes and hot melt pillars is set to at least four. This further improves the connection strength between the top cover and the lower plastic part.

[0015] Secondly, this application provides a battery that includes the battery cell described in the above embodiments.

[0016] Thirdly, this application provides an electrical device that includes the battery described in the above embodiments, the battery being used to provide electrical energy.

[0017] The battery and power supply device according to this application also have the same advantages as the battery cell according to this application, which will not be repeated here.

[0018] 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

[0019] 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:

[0020] Figure 1 This is a schematic diagram of the structure of a vehicle according to an embodiment of this application;

[0021] Figure 2 This is an exploded structural diagram of a battery according to an embodiment of this application;

[0022] Figure 3 This is a schematic perspective view of a battery cell according to an embodiment of this application;

[0023] Figure 4 for Figure 3 A schematic top view of a single battery cell;

[0024] Figure 5 For along Figure 4 A schematic cross-sectional view of a single battery cell taken by line EE in the diagram;

[0025] Figure 6 for Figure 5 A schematic enlarged view of region F of one embodiment of a battery cell;

[0026] Figure 7 for Figure 5 A schematic enlarged view of region F of another embodiment of the battery cell;

[0027] Figure 8 for Figure 3 A schematic front view of a single battery cell;

[0028] Figure 9 For along Figure 8 A schematic cross-sectional view of a single battery cell taken by line AA in the diagram;

[0029] Figure 10 for Figure 9 A schematic enlarged view of region B of a single battery cell;

[0030] Figure 11 For use Figure 3 A schematic bottom view of the top cover of the battery cell; and

[0031] Figure 12 For use Figure 3 A schematic top view of the lower plastic part of the battery cell.

[0032] The reference numerals in the detailed embodiments are as follows:

[0033] 1000 vehicles, 1100 batteries, 1200 controllers, 1300 motors;

[0034] 100 Battery housing, 110 Part 1, 120 Part 2;

[0035] 200 battery cells,

[0036] 210 Top cover, 211 Top cover sheet, 220 Housing, 230 Lower plastic part, 231 Hot melt column, 240 Bare cell, 241 Tab;

[0037] 2111 Hot melt hole, 2112 First-stage inverted step; 2113 Second-stage inverted step. Detailed Implementation

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0044] 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.

[0045] 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.

[0046] Generally, some types of battery cells (especially prismatic battery cells) may include a top cover, which may be configured to provide functions such as fixing and sealing, current conduction, pressure relief, and fuse protection. The top cover may include, for example: a top cover sheet for fixing and sealing; terminal post assemblies for connecting the positive and negative terminals of the battery; an explosion-proof device for releasing pressure to prevent explosion when the internal pressure of the battery is too high; an injection hole for injecting electrolyte and sealing it with a sealing pin or sealing ball; and a sealing ring for ensuring a tight seal between the top cover and the housing to prevent electrolyte leakage. Furthermore, the top cover may cooperate with upper and lower plastic parts, wherein the upper plastic part may be configured for the terminal post portion of the top cover to achieve insulation and fixing, while the lower plastic part may be configured to achieve sealing and insulation between the top cover and the battery cell.

[0047] A hot-melt post can be provided between the lower plastic part and the top cover plate of the top cover for connecting and fixing the top cover and the lower plastic part. In this case, by mates the hot-melt post with a countersunk hole or hot-melt hole on the top cover plate and melts the hot-melt post to fill the countersunk hole or hot-melt hole using ultrasonic welding or other heating methods, a firm connection can be formed between the top cover and the lower plastic part after the hot-melt post cools. Furthermore, to enhance the reliability of the connection, an undercut structure can be provided in the countersunk hole of the top cover plate, which can interlock with the hot-melt post.

[0048] However, the lower plastic part is usually made of polypropylene (PP), and the softening temperature of PP is about 120°C. Therefore, under high temperature conditions, the hot melt column connecting the lower plastic part to the top cover may soften, causing the lower plastic part to detach from the top cover sheet.

[0049] For example, see Figures 8 to 10 The diagram shows a battery cell 200, which includes a top cover 210 with a top cover sheet 211, a housing 220, a lower plastic part 230, and a bare cell 240. Once the lower plastic part 230 detaches from the top cover sheet 211, it adversely affects the height space between the bare cell 240 and the lower plastic part 230. Therefore, in this situation, the lower plastic part 230 can press down on the electrodes of the bare cell 240, causing lithium plating in the bare cell 240, leading to a short circuit and a series of thermal runaway events, which is extremely harmful to the battery.

[0050] In view of this, the concept of this application is to provide one or more stepped inverted structures in the hot-melt holes of the top cover sheet of the battery cell to increase the stress area of ​​the hot-melt column of the lower plastic part on the top cover sheet. On the other hand, the material of the lower plastic part can be selected as a material with a high softening temperature and electrolyte resistance to further prevent the lower plastic part from detaching from the top cover sheet after softening, and thus prevent the lower plastic part from causing lithium plating and short circuit due to the pressure electrode sheet.

[0051] This application provides a single battery cell, which can be used, but is not limited to, in battery modules, battery packs, batteries, etc.

[0052] This application also provides a battery having the battery cells described in this application, which can be used, but is not limited to, in electrical devices such as vehicles, ships, or aircraft. The power system of such an electrical device can be composed of batteries having the battery cells described in this application. This is beneficial for improving battery safety, stability, and battery life.

[0053] This application also provides an electrical device incorporating the battery of this application embodiment, which may, but is not limited to, be configured as a mobile phone, tablet, laptop, electric toy, power tool, electric vehicle, electric car, ship, spacecraft, etc. The electric toy may include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., while the spacecraft may include airplanes, rockets, space shuttles, and spacecraft, etc.

[0054] 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.

[0055] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 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 1100 is disposed inside the vehicle 1000, and the battery 1100 can be located at the bottom, front, or rear of the vehicle 1000. The battery 1100 can be used to power the vehicle 1000; for example, the battery 1100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 1200 and a motor 1300. The controller 1200 is used to control the battery 1100 to supply power to the motor 1300, for example, to meet the power needs of the vehicle 1000 during startup, navigation, and driving.

[0056] In some embodiments of this application, the battery 1100 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.

[0057] Please refer to Figure 2 , Figure 2This is an exploded view of a battery 1100 provided in some embodiments of this application. The battery 1100 includes a battery housing 100 and a battery cell 200, with the battery cell 200 housed within the battery housing 100. The battery housing 100 provides a space for the battery cell 200, and can employ various structures. In some embodiments, the battery housing 100 may include a first portion 110 and a second portion 120, which overlap each other, jointly defining a space for accommodating the battery cell 200. The second portion 120 may be a hollow structure open at one end, and the first portion 110 may be a plate-like structure, covering the open side of the second portion 120 so that the first portion 110 and the second portion 120 jointly define the space; alternatively, the first portion 110 and the second portion 120 may both be hollow structures open on one side, with the open side of the first portion 110 covering the open side of the second portion 120. Of course, the battery box 100 formed by the first part 110 and the second part 120 can be of various shapes, such as cylinder, cuboid, etc.

[0058] In battery 1100, there can be multiple battery cells 200, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 200 are connected in both series and parallel configurations. Multiple battery cells 200 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 200 is housed within battery housing 100. Alternatively, battery 1100 can also be composed of multiple battery cells 200 first connected in series, parallel, or in a mixed manner to form a battery module, and then multiple battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within battery housing 100. Battery 1100 may also include other structures; for example, battery 1100 may also include a busbar component for electrical connection between multiple battery cells 200.

[0059] Each battery cell 200 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 200 can be cylindrical, flat, cuboid, or other shapes.

[0060] Please refer to Figures 3 to 12 , Figure 3 This is a schematic perspective view of a battery cell 200 according to an embodiment of this application; Figure 4 for Figure 3 A schematic top view of a single battery cell 200; Figure 5 For along Figure 4 A schematic cross-sectional view of the battery cell 200 taken by line EE in the diagram; Figure 6 for Figure 5A schematic enlarged view of region F of one embodiment of the battery cell 200; Figure 7 for Figure 5 A schematic enlarged view of region F of another embodiment of the battery cell 200; Figure 8 for Figure 3 A schematic front view of a single battery cell; Figure 9 For along Figure 8 A schematic cross-sectional view of a single battery cell taken by line AA in the diagram; Figure 10 for Figure 9 A schematic enlarged view of region B of a single battery cell; Figure 11 For use Figure 3 A schematic bottom view of the top cover of the battery cell; and Figure 12 For use Figure 3 A schematic top view of the lower plastic component of a battery cell. The battery cell 200 can be the smallest unit comprising a battery. Here, the battery cell 200 is advantageously constructed as a square battery cell. The battery cell 200 may include a top cover 210, a housing 220, a lower plastic component 230, and a bare cell 240.

[0061] As previously described, the top cover 210 may be configured to perform functions such as fixing and sealing, current conduction, pressure relief, and fusible protection. The top cover 210 may include a top cover plate 211, an electrode assembly, an explosion-proof device, a liquid injection hole, and a sealing ring. The top cover plate 211 of the top cover 210 may have at least one heat-fusion hole 2111, which can mate with the heat-fusion post 231.

[0062] The housing 220 is a component used to cooperate with the top cover 210 to form the internal environment of the battery cell 200, wherein the formed internal environment can accommodate the bare cell 240, electrolyte, and other components. The housing 220 and the top cover 210 can be independent components. An opening can be provided on the housing 220, and the top cover 210 can close the opening to form the internal environment of the battery cell 200. Alternatively, the top cover 210 and the housing 220 can be integrated. Specifically, the top cover 210 and the housing 220 can form a common connecting surface before other components are inserted into the housing. The housing 220 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 220 can be determined according to the specific shape and size of the bare cell 240. The material of the housing 220 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment does not impose any special limitations on this.

[0063] The lower plastic component 230 can be configured to achieve sealing and insulation between the top cover 210 and the bare battery cell 240. At least one hot-melt post 231 can be disposed between the lower plastic component 230 and the top cover plate 211 of the top cover 210 for connecting and securing the top cover 210 and the lower plastic component 230. Here, by engaging the hot-melt post 231 with a hot-melt hole 2111 on the top cover plate 211 and melting the hot-melt post 231 using ultrasonic welding or other heating methods to fill the hot-melt hole 2111, a strong connection can be formed between the top cover 210 and the lower plastic component 230 after the hot-melt post 231 cools.

[0064] A bare cell 240 is the component in a single battery cell 200 where an electrochemical reaction occurs. The casing 220 may contain one or more bare cells 240. A bare cell 240 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of the cell assembly, while the portions of the positive and negative electrode sheets without active material each constitute a tab 241. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte, and the tabs 241 connect to the electrode terminals to form a current loop.

[0065] According to some embodiments of this application, refer to Figures 3 to 7 A battery cell 200 is provided, which may include a top cover 210 having a top cover sheet 211 and a lower plastic part 230. The top cover sheet 211 may have at least one hot-melt hole 2111, and at least one hot-melt post 231 may be provided on the lower plastic part 230, wherein the at least one hot-melt post 231 is disposed with the at least one hot-melt hole 2111 and is respectively alignable with the disposed hot-melt hole 2111. The at least one hot-melt hole 2111 may include at least one inverted step on its cross-section parallel to its depth direction. For example, in Figure 6 In one embodiment, the hot-melt hole 2111 includes a first-stage inverted step 2112; while Figure 7 In one embodiment, the hot-melt hole 2111 includes a first-stage inverted step 2112 and a second-stage inverted step 2113.

[0066] Therefore, the inverted step of the hot-melt hole 2111 increases the stress-bearing area of ​​the hot-melt pillar 231 in the top cover sheet 211, thereby improving the connection strength between the lower plastic part 230 and the top cover 210. This prevents the lower plastic part 230 from detaching from the hot-melt hole 2111 on the top cover sheet 211 after softening, thus preventing lithium plating and short circuits caused by the lower plastic part 230 pressing against the electrode. Therefore, it improves the structural stability, safety, and service life of the battery cell.

[0067] According to some embodiments of this application, optionally, the number of steps of the at least one inverted step can be determined by the thickness of the top cover plate 211. This allows the number of inverted steps to be set as needed, thereby increasing the connection strength as required. In currently conventional battery cells, such... Figure 7 The two-stage inverted steps shown are the first inverted step 2112 and the second inverted step 2113.

[0068] According to some embodiments of this application, optionally, and particularly referring to... Figure 7 The width d of the step is formed by half the difference between the wider upper edge and the narrower lower edge of the inverted step, which can be in the range of 0.1 mm to 0.6 mm, particularly in the range of 0.2 mm to 0.4 mm. It is conceivable that the force-bearing area of ​​the hot-melt column 231 in the top cover plate 211 can depend on the difference between the wider upper edge and the narrower lower edge of the inverted step, and thus on the width d. It is also conceivable that if the width d is too large, the hot-melt column 231 will have difficulty completely filling the hot-melt hole 2111 of the top cover plate 211 during hot melting, while if the width d is too small, the required connection strength between the plastic part 230 and the top cover 210 may not be met.

[0069] According to some embodiments of this application, optionally, and particularly referring to... Figure 7 The height h of the inverted step can be in the range of 0.1mm to 0.8mm, especially in the range of 0.3mm to 0.5mm. It is conceivable that if the height h of the inverted step is too small, the hot melt column 231 is prone to breakage when hot melted, for example, by ultrasonic welding, while if the height h of the inverted step is too large, the lower plastic part 230 will no longer have space for inverted fastening.

[0070] According to some embodiments of this application, optionally, and particularly referring to... Figure 6 and Figure 7 The inverted step may have a transition fillet with a radius R that can be in the range of 0.03 mm to 0.6 mm, particularly in the range of 0.05 mm to 0.15 mm. The transition fillet reduces stress concentration, thereby reducing or preventing fracture of the hot-melt column 231, for example, during ultrasonic welding. It is conceivable that if the transition fillet is too large, the width d will be reduced; if the transition fillet is too small, stress concentration is likely to occur.

[0071] According to some embodiments of this application, optionally, and particularly referring to... Figure 7 At least one hot-melt hole 2111 may include multiple inverted steps on its cross-section parallel to its depth direction, and the upper inverted step (e.g.) Figure 7The cross-sectional dimensions of the first inverted step (2112) can be smaller than those of the inverted step below (e.g., Figure 7 The cross-sectional dimensions of the second-level inverted step 2113 in the middle. This facilitates the complete filling of the hot melt hole 2111 by the hot melt column 231 during hot melting.

[0072] According to some embodiments of this application, optionally, the lower plastic part 230 may be made of polybutylene terephthalate (PBT). PBT is a material with a high softening temperature and resistance to electrolytes, and the softening temperature of PBT can be about 180°C, thereby preventing the lower plastic part 230 from detaching from the hot melt hole 2111 of the top cover sheet 211 after softening. Moreover, PBT is similar in price to PP, so the problem of short-circuit thermal runaway can be solved with virtually no increase in cost.

[0073] Furthermore, it is conceivable that the lower plastic part 230 could be constructed from a mixed alloy comprising polybutylene terephthalate (PBT) and polyethylene terephthalate (PET). Since the softening temperature of PBT is approximately 180°C and that of PET is approximately 140°C, the softening temperature of the mixed alloy could reach approximately 170°C, thereby increasing the softening temperature of the lower plastic part. Moreover, the prices of PET and PBT are similar to those of PP, thus reducing cost increases in the event of short-circuit thermal runaway.

[0074] According to some embodiments of this application, optionally, and particularly referring to... Figure 6 The lower plastic part 230 and the hot-melt column 231 can be integrally molded. This can further improve the connection strength between the top cover and the lower plastic part.

[0075] According to some embodiments of this application, optionally, and particularly referring to... Figure 11 and Figure 12 The number of hot melt holes 2111 and hot melt pillars 231 can both be set to at least four. This can further improve the connection strength between the top cover and the lower plastic part.

[0076] According to some embodiments of this application, this application also provides a battery 1100, including the battery cell 200 described in any of the above embodiments.

[0077] According to some embodiments of this application, this application also provides an electrical device including the battery 1100 described in any of the above embodiments, and the battery 1100 can be used to provide electrical energy to the electrical device.

[0078] The electrical device can be any of the aforementioned battery-powered devices or systems.

[0079] According to some embodiments of this application, particularly referring to Figures 3 to 12This application provides a battery cell 200, which includes a top cover 210 with a top cover sheet 211 and a lower plastic part 230. The top cover sheet 211 has at least one hot-melt hole 2111 and the lower plastic part 230 is provided with at least one hot-melt post 231. The at least one hot-melt post 231 is disposed with the at least one hot-melt hole 2111 and can be aligned with the corresponding hot-melt hole 2111. The at least one hot-melt hole 2111 includes a first-level inverted step, i.e., a first-level inverted step 2112, or two-level inverted steps, i.e., a first-level inverted step 2112 and a second-level inverted step 2113, on its cross-section parallel to its depth direction. The width d of the inverted step is in the range of 0.1 mm to 0.6 mm, the height h of the inverted step is in the range of 0.1 mm to 0.8 mm, and the radius R of the transition fillet of the inverted step is in the range of 0.03 mm to 0.6 mm. The lower plastic part 230 is made of polybutylene terephthalate, and the lower plastic part 230 and the hot melt column 231 are integrally molded structures.

[0080] Therefore, in the battery cell according to the embodiments of this application, on the one hand, by adding one or more stepped inverted structures in the hot-melt holes of the top cover sheet, the stress-bearing area of ​​the hot-melt column of the lower plastic part in the top cover sheet is increased. On the other hand, by making the lower plastic part from PBT, a material with a high softening temperature and high electrolyte resistance, the softening temperature of the lower plastic part can be greater than 170°C. Therefore, it is possible to prevent the lower plastic part from detaching from the inverted holes of the top cover sheet after softening, thus preventing it from pressing down on the electrode of the bare cell and causing lithium plating leading to a short circuit. Therefore, the connection strength between the top cover and the lower plastic part is improved, thereby improving the structural stability, safety, and service life of the battery cell.

[0081] 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 comprising a top cover (210) having a top cover sheet (211) with at least one hot melt hole (2111) and a lower plastic part (230) provided with at least one hot melt post (231) on the lower plastic part (230), the at least one hot melt post (231) being assigned to the at least one hot melt hole (2111) and being respectively alignable with the assigned hot melt hole (2111), characterized in that, The at least one hot-melt hole (2111) comprises at least one inverted step in a cross section thereof parallel to a depth direction thereof.

2. The battery cell of claim 1, wherein, The number of the at least one inverted step is determined by a thickness of the top cover sheet (211).

3. The battery cell of claim 1, wherein, A half of a difference between a wider upper edge and a narrower lower edge of the inverted step constitutes a width of the inverted step, which is in a range between 0.1 mm and 0.6 mm.

4. The battery cell of claim 1, wherein, A height of the inverted step is in a range between 0.1 mm and 0.8 mm.

5. The battery cell as described in claim 1, characterized in that, The inverted step has a transition round corner with a radius in a range between 0.03 mm and 0.6 mm.

6. The battery cell of claim 1, wherein, The at least one hot-melt hole (2111) comprises a plurality of inverted steps in a cross section thereof parallel to a depth direction thereof, and a cross section size of an upper inverted step is smaller than a cross section size of a lower inverted step.

7. The battery cell of any one of claims 1 to 6, wherein, The lower plastic part (230) is made of polybutylene terephthalate.

8. The battery cell of any one of claims 1 to 6, wherein, The lower plastic part (230) and the hot-melt column (231) are integrally formed.

9. The battery cell of any one of claims 1 to 6, wherein, The number of the hot-melt holes (2111) and the number of the hot-melt columns (231) are both set to at least four.

10. A battery, characterized by Comprising: The battery cell of any one of claims 1 to 9.

11. An electrical device, characterized by The electrical device comprises the battery of claim 10, which is used to provide electrical energy.

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