A battery cell, a battery device, a power consumption device, and an energy storage device

Abstract

The application provides a battery monomer, a battery device, a power utilization device and an energy storage device. The battery monomer comprises a top cover assembly, a shell, a connecting piece and a battery core assembly. The top cover assembly comprises a pole, an aluminum sheet and a lower plastic. The lower plastic is located on one side of the aluminum sheet along the thickness direction of the top cover assembly. The connecting piece comprises a first connecting section and a second connecting section, and the cross-sectional area of the first connecting section is smaller than that of the second connecting section. The lower plastic is provided with a mounting groove, the mounting groove comprises a first groove section and a second groove section, the cross-sectional area of the first groove section is smaller than that of the second groove section, the second connecting section is located in the second groove section, and at least part of the first connecting section is located in the first groove section. Such a design can improve the stability of the connection between the aluminum sheet and the lower plastic.

Description

Technical Field

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

[0002] With technological advancements, the application of new energy technologies such as batteries is becoming increasingly widespread. A battery includes a top cover assembly, which consists of interconnected aluminum sheets and a lower plastic layer. This seal seals the internal structure, including the battery cells, preventing external impurities from entering the battery and preventing electrolyte leakage. Therefore, the quality of the connection between the aluminum sheet and the lower plastic layer affects the battery's quality and lifespan. Utility Model Content

[0003] This application provides a battery cell, a battery device, an electrical device, and an energy storage device to improve the stability of the connection between the aluminum sheet and the lower plastic sheet.

[0004] This application provides a battery cell, which includes a top cover assembly, a housing, and a cell assembly. The housing has a receiving cavity, and the cell assembly is located in the receiving cavity. The top cover assembly is connected to the housing. The top cover assembly includes a terminal post, an aluminum sheet, and a lower plastic. The terminal post is mounted on the aluminum sheet along the thickness direction of the top cover assembly, and the lower plastic is located on one side of the aluminum sheet. The top cover assembly further includes at least one connector, which connects the aluminum sheet and the lower plastic. The connector includes a first connecting segment and a second connecting segment that are connected to each other. In a cross-section perpendicular to the thickness direction of the top cover assembly, the cross-sectional area of ​​the first connecting segment is smaller than the cross-sectional area of ​​the second connecting segment. The first connecting segment is connected to the aluminum sheet. The lower plastic section is provided with at least one mounting groove, the mounting groove including a first groove segment and a second groove segment that are interconnected. The first groove segment is located on the side of the second groove segment facing the light aluminum sheet. In a cross section perpendicular to the thickness direction of the top cover assembly, the cross-sectional area of ​​the second groove segment is larger than the cross-sectional area of ​​the first groove segment, and the cross-sectional area of ​​the first groove segment is smaller than the cross-sectional area of ​​the second connecting segment. The second connecting segment is located in the second groove segment, and at least a portion of the first connecting segment is located in the first groove segment.

[0005] In one possible implementation, the aluminum sheet has at least one recess on the side facing the lower plastic, and the recess is recessed in a direction away from the lower plastic. At least a portion of the first connecting segment protrudes along the thickness direction of the top cover assembly relative to the side of the lower plastic facing the aluminum sheet, and the protruding portion extends into the recess.

[0006] In one possible implementation, at least one end of the mounting groove extends through the edge of the lower plastic along its length or width.

[0007] In one possible implementation, a protrusion is provided on the side of the lower plastic away from the light aluminum sheet, and a plane perpendicular to the thickness direction of the top cover assembly is defined as a first plane, and the projection of the mounting groove onto the first plane is located within the projection range of the protrusion onto the first plane.

[0008] In one possible implementation, the connector extends along the thickness direction of the top cover assembly, and a direction perpendicular to the thickness direction of the top cover assembly is defined as a first direction. Along the first direction, the dimension a of the first connecting segment satisfies: 3 mm ≤ a ≤ 10 mm, and the dimension b of the second connecting segment satisfies: 3 mm < b ≤ 16 mm.

[0009] In one possible implementation, the connector extends along the thickness direction of the top cover assembly, and a direction perpendicular to the thickness direction of the top cover assembly is defined as a first direction. Along the first direction, the dimensions a of the first connecting segment and b of the second connecting segment satisfy 0 mm < (ba) ≤ 13 mm.

[0010] In one possible implementation, along the direction perpendicular to the thickness direction of the top cover assembly, the cross-sectional area m of the first connecting segment satisfies: 15 mm² ≤ m ≤ 105 mm², and / or the cross-sectional area n of the second connecting segment satisfies: 15 mm² < m ≤ 560 mm².

[0011] In one possible implementation, the first connecting segment has a size of 0.5 mm to 2.5 mm along the thickness direction of the top cover assembly, and the second connecting segment has a size of 0.5 mm to 2.5 mm.

[0012] In one possible implementation, the first connecting segment is connected to the aluminum sheet by a weld or integrally formed.

[0013] In one possible implementation, the lower plastic is integrally molded, or; The lower plastic part has a larger dimension along the length of the top cover assembly than the same dimension along the width of the top cover assembly. The lower plastic part includes at least a first main body and a second main body, which are connected along the length of the top cover assembly. The first main body and the second main body are respectively provided with the mounting groove.

[0014] In one possible implementation, the mounting slot includes a first mounting slot and a second mounting slot, the first mounting slot being disposed on the first main body portion and the second mounting slot being disposed on the second main body portion. Along the width direction of the battery cell, the first mounting slot penetrates the first main body portion and the second mounting slot penetrates the second main body portion.

[0015] This application also provides a battery device, which includes any of the battery cells described above, and the battery device includes one or more of the following: battery module, battery pack, and energy storage battery.

[0016] This application also provides an electrical device, which includes the battery device described above, and the battery device is used to provide electrical energy.

[0017] This application embodiment also provides an energy storage device, which includes the battery device described above, and the battery device is used to provide electrical energy.

[0018] This application provides a battery cell, a battery device, a power consumption device, and an energy storage device. The battery cell includes a top cover assembly, a housing, a connector, and a cell assembly. The top cover assembly includes terminals, an aluminum sheet, and a lower plastic layer. Along the thickness direction of the top cover assembly, the lower plastic layer is located on one side of the aluminum sheet. The connector includes a first connecting segment and a second connecting segment, with the cross-sectional area of ​​the first connecting segment being smaller than that of the second connecting segment. The lower plastic layer has a mounting groove, which includes a first groove segment and a second groove segment. The cross-sectional area of ​​the first groove segment is smaller than that of the second groove segment. The second connecting segment is located in the second groove segment, and at least a portion of the first connecting segment is located in the first groove segment. This design improves the stability of the connection between the aluminum sheet and the lower plastic layer. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a battery cell provided in an embodiment of this application; Figure 2 This is an exploded view of a single battery cell provided in an embodiment of this application; Figure 3 A schematic diagram of the top cover assembly provided in an embodiment of this application; Figure 4 This is an exploded view of the top cover assembly provided in an embodiment of this application; Figure 5 This is a cross-sectional view of the top cover assembly provided in an embodiment of this application; Figure 6 for Figure 5 A magnified view of the central position (I). Figure 7 This is a cross-sectional view of another embodiment of the top cover assembly provided in this application. Figure 8 for Figure 7 A magnified view of a portion of position II; Figure 9 This is a partial exploded view of the top cover assembly provided in an embodiment of this application; Figure 10 This is a schematic diagram of the lower plastic material provided in an embodiment of this application; Figure 11 A schematic diagram of the connector provided in an embodiment of this application; Figure 12 This is a schematic diagram of another embodiment of the connector provided in the embodiments of this application; Figure 13 This is a schematic diagram of another embodiment of the plastic material provided in this application.

[0020] Figure Labels 1-Shell; 2-Top cover assembly; 21-Pole Column; 22-Bright aluminum sheet; 221 - Depression; 23-Lower plastic; 231 - Mounting slot; 231a - First Slot Section; 231b - Second section; 231c - First mounting slot; 231d - Second mounting slot; 232 - Protrusion; 233-First Main Body Section; 234 - Second Main Body; 24-Connector; 241 - First connecting segment; 242 - Second connecting segment; 25-Top patch; 3-Battery cell assembly. Detailed Implementation

[0021] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0022] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0023] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0024] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0025] like Figure 1 and Figure 2 As shown, this application embodiment provides a battery cell, which includes a top cover assembly 2, a housing 1, and a cell assembly 3, etc. The housing 1 has a receiving cavity, and the cell assembly 3 is located in the receiving cavity and in contact with the electrolyte. The top cover assembly 2 is connected to the housing 1 to seal the receiving cavity. Figure 3 As shown, the top cover assembly 2 includes a terminal post 21, a light aluminum sheet 22, and a lower plastic insert 23. The terminal post 21 is mounted on the light aluminum sheet 22 and is electrically connected to the cell assembly 3. The cell assembly 3 has electrodes and tabs, wherein the tabs are electrically connected to the terminal post 21. Current can be transmitted between the cell assembly 3 and the terminal post 21. Along the thickness direction of the top cover assembly 2, the lower plastic insert 23 is located on one side of the light aluminum sheet 22. The lower plastic insert 23 is located on the side of the light aluminum sheet 22 facing the inside of the battery cell, and serves to provide insulation and sealing, preventing dust, moisture, and other foreign matter from entering the battery cell while also preventing electrolyte leakage.

[0026] like Figure 4 , Figure 5 and Figure 6As shown, the top cover assembly 2 includes at least one connector 24, which connects the aluminum sheet 22 and the lower plastic 23. The connector 24 includes a first connecting segment 241 and a second connecting segment 242 that are interconnected. In a cross-section perpendicular to the thickness direction of the top cover assembly 2, the cross-sectional area of ​​the first connecting segment 241 is smaller than the cross-sectional area of ​​the second connecting segment 242. That is, along the length and width directions of the top cover assembly 2, the dimension of the first connecting segment 241 in at least one direction is smaller than the dimension of the second connecting segment 242 in the same direction. The lower plastic 23 has at least one mounting groove 231, which includes a first groove segment 231a and a second groove segment 231b that are interconnected. The first groove segment 231a is located on the side of the second groove segment 231b facing the aluminum sheet 22. In a cross-section perpendicular to the thickness direction of the top cover assembly 2, the cross-sectional area of ​​the second groove segment 231b is larger than the cross-sectional area of ​​the first groove segment 231a, and the cross-sectional area of ​​the first groove segment 231a is smaller than the cross-sectional area of ​​the second connecting segment 242. Along the length and width directions of the top cover assembly 2, the dimension of the first groove segment 231a is smaller than the dimension of the second groove segment 231b along the same direction at least in one of the directions. The second connecting segment 242 is located in the second groove segment 231b, at least a portion of the first connecting segment 241 is located in the first groove segment 231a, and the first connecting segment 241 is connected to the light aluminum sheet 22.

[0027] The connector 24 can be a stepped structure. Since the cross-sectional area of ​​the first groove segment 231a is smaller than the cross-sectional area of ​​the second connecting segment 242, the second connecting segment 242 can be restricted from disengaging from the second groove segment 231b by the first groove segment 231a, thereby improving the stability of the fit between the connector 24 and the mounting groove 231.

[0028] like Figure 7 , Figure 8 and Figure 9 As shown, in one possible embodiment, the aluminum sheet 22 has at least one recess 221 on the side facing the lower plastic 23, the recess 221 being recessed away from the lower plastic 23. At least a portion of the first connecting section 241 protrudes along the thickness direction of the top cover assembly 2 relative to the side of the lower plastic 23 facing the aluminum sheet 22, and a portion of the protrusion 232 can extend into the recess 221 of the aluminum sheet 22.

[0029] This design increases the contact area between the protrusion 232 and the first connecting section 241, thereby improving the stability of the connection between the connector 24 and the aluminum sheet 22. When assembling the aluminum sheet 22 and the lower plastic 23, the first connecting section 241 extending into the recess 221 can also position and limit the aluminum sheet 22 and the lower plastic 23, reducing the possibility of relative displacement between them along the thickness direction perpendicular to the top cover assembly 2, thus improving the relative positional accuracy between the aluminum sheet 22 and the lower plastic 23.

[0030] When assembling the top cover assembly 2, the connector 24 can be set on the lower plastic 23 by injection molding. Then, the light aluminum sheet 22 and the lower plastic 23 are combined, and the light aluminum sheet 22 and the connector 24 are welded or connected by bonding at the corresponding positions, so that the connector 24 and the light aluminum sheet 22 are connected.

[0031] like Figure 10 As shown, in one possible implementation, at least one end of the mounting groove 231 extends through the edge of the lower plastic 23 along the length or width direction of the lower plastic 23.

[0032] The mounting groove 231 can form an opening through one end of the lower plastic 23, making the installation process simpler and more convenient when the connector 24 is inserted into the mounting groove 231 along the opening.

[0033] This design allows the connector 24 to be connected to the aluminum sheet 22 first, and then the aluminum sheet 22 to be assembled with the lower plastic 23. This helps to reduce the interference of the lower plastic 23 with the welding of the connector 24 and the aluminum sheet 22, reducing the welding difficulty. At the same time, it can also reduce the impact of the high temperature of welding on the lower plastic 23, which is beneficial to improving the quality of the battery cell.

[0034] like Figure 10 As shown, in one possible implementation, a protrusion 232 is provided on the side of the lower plastic 23 away from the light aluminum sheet 22, and the protrusion 232 protrudes in a direction away from the light aluminum sheet 22. A plane perpendicular to the thickness direction of the top cover assembly 2 is defined as the first plane, and the projection of the mounting groove 231 onto the first plane is located within the projection range of the protrusion 232 onto the first plane.

[0035] This design allows for the thickening of certain areas of the lower plastic 23, thus meeting the depth requirements of the mounting groove 231. Other areas of the lower plastic 23 can be thinned to a depth less than the mounting groove 231, thereby reducing the overall thickness and volume of the lower plastic 23. The reduced space occupied by the lower plastic 23 allows for more space in the battery cell to house the cell assembly 3 and electrolyte, which is beneficial for increasing the capacity of the battery cell and better meeting practical application needs.

[0036] like Figure 11As shown, in one possible implementation, the connector 24 extends along the thickness direction of the top cover assembly 2. The direction perpendicular to the thickness of the top cover assembly 2 is defined as a first direction. Along this first direction, the dimension of the first connecting segment 241 is 3 mm ≤ a ≤ 10 mm, and the dimension b of the second connecting segment 242 satisfies: 3 mm < b ≤ 16 mm. The dimension of the first connecting segment 241 can be 3 mm, 4 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, etc. The dimension of the second connecting segment 242 can be 3.5 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, etc.

[0037] When the dimensions of the first connecting segment 241 and the second connecting segment 242 are too small, the connection stability between the connector 24 and the aluminum sheet 22 and the lower plastic 23 is poor. When the dimensions of the connector 24 are too large, the connector 24 has a large volume, which can easily lead to the top cover assembly 2 occupying a large space, which in turn will occupy the space of the cell assembly 3, affecting the volume of the cell assembly 3 and the capacity of the electrolyte, thus leading to a reduction in the capacity of the battery cell.

[0038] In one possible implementation, a and b satisfy 0 mm < (ba) ≤ 13 mm. The value of ba can be 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, etc.

[0039] This design allows the connector 24 to form a stepped structure, thereby reducing the possibility of the second connecting segment 242 detaching from the second groove segment 231b along the first groove segment 231a, which helps improve the stability of the fit between the connector 24 and the lower plastic 23. When the value of ba is too large, the size of the second connecting segment 242 is too large, which may easily interfere with the internal structure of the battery cell, such as the tabs and the connecting pieces welded to the tabs.

[0040] In one possible implementation, in the cross-section along the thickness direction perpendicular to the top cover assembly 2, the cross-sectional area *m* of the first connecting segment 241 satisfies 15 mm² ≤ *m* ≤ 105 mm², and the cross-sectional area *n* of the second connecting segment 242 satisfies 15 mm² < *m* ≤ 560 mm². The cross-sectional area of ​​the first connecting segment 241 can be 15 mm², 25 mm², 35 mm², 45 mm², 55 mm², 65 mm², 75 mm², 85 mm², 95 mm², 105 mm², etc. The cross-sectional area of ​​the second connecting segment 242 can be 16 mm², 50 mm², 100 mm², 150 mm², 200 mm², 250 mm², 300 mm², 350 mm², 400 mm², 450 mm², 500 mm², 550 mm², 560 mm², etc.

[0041] When the cross-sectional areas of the first connecting segment 241 and the second connecting segment 242 are too small, the connection stability between the connector 24 and the aluminum sheet 22 and the lower plastic 23 is poor. When the cross-sectional areas of the first connecting segment 241 and the second connecting segment 242 are too large, the connector 24 is prone to interference with components such as the terminal post 21, the electrode tab, and the connecting piece, and occupies a large amount of space, affecting the capacity of the battery cell. Therefore, by adopting the cross-sectional area provided in the embodiments of this application, the space occupied by the connector 24 can be reduced while satisfying the connection stability.

[0042] In one possible implementation, along the thickness direction of the top cover assembly 2, the first connecting segment 241 has a dimension of 0.5 mm to 2.5 mm, and the second connecting segment 242 has a dimension of 0.5 mm to 2.5 mm. The dimension of the first connecting segment 241 can be 0.5 mm, 0.7 mm, 0.9 mm, 1.1 mm, 1.3 mm, 1.5 mm, 1.7 mm, 1.9 mm, 2.1 mm, 2.3 mm, 2.5 mm, etc. The dimension of the second connecting segment 242 can be 0.5 mm, 0.7 mm, 0.9 mm, 1.1 mm, 1.3 mm, 1.5 mm, 1.7 mm, 1.9 mm, 2.1 mm, 2.3 mm, 2.5 mm, etc.

[0043] When the dimensions of the first connecting segment 241 and the second connecting segment 242 are too large, it increases the thickness of the top cover assembly 2, thereby occupying space in the cell assembly 3 and reducing the capacity of the individual battery cells. When the dimensions of the first connecting segment 241 and the second connecting segment 242 are too small, it reduces the stability of the fit between the connector 24 and the lower plastic 23. Therefore, a dimension of 0.5 mm to 2.5 mm for the first connecting segment 241 and a dimension of 0.5 mm to 2.5 mm for the second connecting segment 242 can reduce the volume of the connector 24 while meeting the connection strength requirements, which is more in line with actual usage needs.

[0044] like Figure 11 and Figure 12 As shown, the connector 24 can be a rectangular step structure or a cylindrical step structure, etc.

[0045] In one possible implementation, the first connecting segment 241 is connected to the aluminum sheet 22 by a weld, or the first connecting segment 241 and the aluminum sheet 22 are integrally formed.

[0046] When the first connecting segment 241 is connected to the aluminum sheet 22 by welding, the connector 24 can be set inside the lower plastic 23 by injection molding during the production of the lower plastic 23. This design can reduce the fit tolerance between the connector 24 and the mounting groove 231, and the contact between the connector 24 and the inner wall of the mounting groove 231 is more stable, which is conducive to improving the stability of the connection between the connector 24 and the lower plastic 23.

[0047] When the first connecting segment 241 and the aluminum sheet 22 are integrally formed, the connection stability between the connector 24 and the aluminum sheet 22 is high, and the overall structural strength is high.

[0048] In one possible implementation, the lower plastic 23 is a one-piece molded structure, or, as... Figure 13 As shown, the dimension of the lower plastic component 23 along the length direction of the top cover assembly 2 is larger than the dimension of the lower plastic component 23 along the width direction of the top cover assembly 2. The lower plastic component 23 includes at least a first main body portion 233 and a second main body portion 234, which are disposed and connected along the length direction of the top cover assembly 2. The first main body portion 233 and the second main body portion 234 are each provided with a mounting groove 231.

[0049] The lower plastic component 23 can be a split structure, which improves its flexibility. By splicing, the structure of the lower plastic component 23 can be adjusted to adapt to different battery cell models. During processing, the mold manufacturing difficulty is relatively lower, resulting in better overall precision and better meeting actual production needs.

[0050] like Figure 13 As shown, in one possible embodiment, the mounting groove 231 extends along the width direction of the battery cell. The mounting groove 231 includes a first mounting groove 231c and a second mounting groove 231d. The first mounting groove 231c is disposed in the first main body portion 233, and the second mounting groove 231d is disposed in the second main body portion 234. Along the width direction of the top cover assembly 2, at least one end of the first mounting groove 231c and the second mounting groove 231d penetrates the lower plastic 23.

[0051] This design allows the aluminum sheet 22 to be connected to both the first main body 233 and the second main body 234 simultaneously. During installation, the connector 24 extends into the corresponding mounting groove 231 through its opening. The mounting groove 231, extending through the lower plastic 23 in its width direction, reduces its size, resulting in a shorter relative displacement distance between the lower plastic 23 and the aluminum sheet 22 during installation, thus increasing installation efficiency. The mounting groove 231 and the connector 24 can form a sliding groove structure, guiding the relative movement of the aluminum sheet 22 and the lower plastic 23, improving the stability of their relative movement and thus enhancing the relative positional accuracy and connection stability.

[0052] Typically, the connection between the lower plastic 23 and the aluminum sheet 22 relies on the electrode post 21. A portion of the lower plastic 23 extends between the electrode post 21 and the aluminum sheet 22, and the compression between the electrode post 21 and the aluminum sheet 22 fixes the lower plastic 23 and the aluminum sheet 22 relatively. Alternatively, the aluminum sheet 22 is cold-forged into a recessed area. Excess material accumulates at the recess opening and protrudes relative to the lower surface of the aluminum sheet 22. The accumulated material area is then flattened, causing the material to backfill the recess and form an inverted shape. A corresponding boss is provided on the lower plastic 23. By heating and pressurizing the boss area of ​​the lower plastic 23, the boss of the lower plastic 23 melts and enters the inverted area. Alternatively, the connection can be achieved using double-sided adhesive.

[0053] This design results in poor relative positional accuracy between the lower plastic sheet 23 and the aluminum sheet 22, making them prone to warping and affecting the welding of the Mylar film, thus impacting the quality of the battery cells. Using double-sided adhesive for bonding carries the risk of electrolyte contamination, and during processing, the adhesive easily attracts dust and other foreign matter. Furthermore, the adhesive is susceptible to failure, reducing the lifespan of the battery cells. The countersunk hole method is prone to metal shavings residue, affecting the flatness of the area near the countersunk hole. Moreover, this method requires a hot-melt process and corresponding equipment, making the process complex and costly.

[0054] By adopting the method provided in this application embodiment, the connector 24 can be fitted with the lower plastic 23 through injection molding or plug-in connection. The connector 24 and the aluminum sheet 22 can be integrally molded or welded. The connection stability between the lower plastic 23 and the aluminum sheet 22 is high, reducing the possibility of warping of the lower plastic 23. Actual testing shows that the warping of the lower plastic 23 can be reduced from 3 mm to 1 mm. Simultaneously, the connection process between the aluminum sheet 22 and the lower plastic 23 can be simplified, reducing processing difficulty and improving production efficiency. Furthermore, the solution provided in this application embodiment has minimal impact on the flatness of the aluminum sheet 22, and the possibility of metal shavings residue is relatively small.

[0055] In the battery cell provided in this embodiment, no additional connection structure or connection process is required between the aluminum sheet 22 and the lower plastic 23. During assembly, the first protrusion 232 simply extends into the first recess 221. To improve the stability of the fit between the first protrusion 232 and the first recess 221, the first protrusion 232 can be tilted, with the first recess 221 corresponding to it. This design increases the contact area between the first protrusion 232 and the first recess 221, reducing the possibility of the aluminum sheet 22 and the lower plastic 23 detaching. The positions of the first protrusion 232 and the first recess 221 are designed to avoid interfering with other components within the battery cell, such as connecting pieces. Adjusting the tilt angle of the first protrusion 232 and the first recess 221 reduces the assembly difficulty of the aluminum sheet 22 and the lower plastic 23. The inclination direction of the first protrusion 232 can be different. For example, along the length of the top cover assembly 2, the first protrusions 232 at both ends of the aluminum sheet 22 are inclined in directions that are far apart from each other. During assembly, the first protrusion 232 on one side can be inserted into the corresponding first recess 221 firstly, and then the other side can be gently pushed and pressed to make the first protrusion 232 on the other side insert into the first recess 221. According to actual measurements, using the method provided in this embodiment, the warpage of the lower plastic 23 can be reduced from 3mm to 1mm. During processing, a stamping method can be used, which can reduce the residue of metal shavings and reduce the impact on the flatness of the aluminum sheet 22. The assembly method is simple and more in line with actual use requirements.

[0056] In one possible implementation, the top cover assembly 2 may further include a top patch 25, with the top patch 25 and the lower plastic 23 located on opposite sides of the aluminum sheet 22 along the thickness direction of the top cover assembly 2. The top patch 25 serves to provide insulation and protection.

[0057] The battery cell provided in this embodiment can improve the connection strength between the aluminum sheet 22 and the lower plastic 23, preventing displacement of internal components due to the expansion and contraction of the cell assembly 3 during charge and discharge cycles, which could affect the normal operation of the battery cell. It also prevents the aluminum sheet 22 from contacting other components, thereby reducing the possibility of insulation failure and short circuits.

[0058] Because the connection strength between the aluminum sheet 22 and the lower plastic 23 is increased in the solution provided in this application embodiment, the battery cell provided in this application embodiment can better meet the needs of long-term energy storage systems. Long-term energy storage refers to energy storage technology where the battery cell can store electrical energy and continuously release it for more than 4 hours or 8 hours. The battery cell has the technical characteristics of large capacity, long lifespan, and high safety. Compared with short-term energy storage systems, long-term energy storage systems have high-capacity batteries, longer storage times, and can cope with the instability of energy functions, providing stable battery support. With the rapid development of renewable resources and the increasing instability of energy supply, long-term energy storage technology will become the main means of energy storage. Long-term energy storage systems can realize energy storage systems that span days, months, and even seasons of charge-discharge cycles, and can meet the long-term stable operation of the power system. Long-term energy storage requires stable operation over extended periods. Improving the connection stability between the aluminum sheet 22 and the lower plastic 23 of the battery cell makes the battery cell structure more stable, reducing the possibility of battery cell failure due to component loosening. This extends the battery cell's lifespan and stability, better meeting the needs of long-term energy storage and reducing operation and maintenance costs. Improving the connection stability between the aluminum sheet 22 and the lower plastic 23 also reduces the possibility of system downtime due to leakage or short circuits caused by structural issues in the battery cell. Therefore, it improves overall performance, safety, and lifespan.

[0059] Based on the battery cells involved in the above embodiments, this application also provides a battery device that can be applied in a vehicle, such as a gasoline-powered vehicle, a natural gas-powered vehicle, an electric vehicle, or a hybrid vehicle, and can be used to supply power to the vehicle. The battery device includes the battery cells involved in any of the above embodiments. Since the battery cells have the above-mentioned technical effects, the battery device including the battery cells also has corresponding technical effects, which will not be elaborated here. The battery device includes one or more of the following: a battery module, a battery pack, and an energy storage battery.

[0060] This application also provides an electrical device, which may be a vehicle or the like. The electrical device may include the battery device involved in any of the above embodiments, and the battery device is used to provide electrical energy.

[0061] This application also provides an energy storage device, which includes the battery device involved in any of the above embodiments, and the battery device is used to provide electrical energy.

Claims

1. A battery cell, characterized in that, The battery cell includes a top cover assembly (2), a housing (1), and a cell assembly (3). The housing (1) has a receiving cavity, and the cell assembly (3) is located in the receiving cavity. The top cover assembly (2) is connected to the housing (1). The top cover assembly (2) includes a terminal post (21), a light aluminum sheet (22), and a lower plastic sheet (23). The terminal post (21) is mounted on the light aluminum sheet (22). Along the thickness direction of the top cover assembly (2), the lower plastic sheet (23) is located on one side of the light aluminum sheet (22). The top cover assembly (2) further includes at least one connector (24), which connects the aluminum sheet (22) and the lower plastic (23). The connector (24) includes a first connecting segment (241) and a second connecting segment (242) that are connected to each other. In a cross section perpendicular to the thickness direction of the top cover assembly (2), the cross-sectional area of ​​the first connecting segment (241) is smaller than the cross-sectional area of ​​the second connecting segment (242). The first connecting segment (241) is connected to the aluminum sheet (22). The lower plastic (23) is provided with at least one mounting groove (231), the mounting groove (231) includes a first groove segment (231a) and a second groove segment (231b) that are interconnected. The first groove segment (231a) is located on the side of the second groove segment (231b) facing the light aluminum sheet (22). In a cross section perpendicular to the thickness direction of the top cover assembly (2), the cross-sectional area of ​​the second groove segment (231b) is larger than the cross-sectional area of ​​the first groove segment (231a), and the cross-sectional area of ​​the first groove segment (231a) is smaller than the cross-sectional area of ​​the second connecting segment (242). The second connecting segment (242) is located in the second groove segment (231b), and at least a portion of the first connecting segment (241) is located in the first groove segment (231a).

2. The battery cell according to claim 1, characterized in that, The aluminum sheet (22) has at least one recess (221) on the side facing the lower plastic (23), and the recess (221) is recessed in a direction away from the lower plastic (23); At least a portion of the first connecting segment (241) protrudes along the thickness direction of the top cover assembly (2) relative to the lower plastic (23) toward the side of the light aluminum sheet (22), and the protruding portion extends into the recess (221).

3. The battery cell according to claim 1, characterized in that, Along the length or width of the lower plastic (23), at least one end of the mounting groove (231) extends through the edge of the lower plastic (23).

4. The battery cell according to claim 1, characterized in that, The lower plastic (23) has a protrusion (232) on the side away from the light aluminum sheet (22). The plane perpendicular to the thickness direction of the top cover assembly (2) is defined as the first plane. The projection of the mounting groove (231) on the first plane is located within the projection range of the protrusion (232) on the first plane.

5. The battery cell according to claim 1, characterized in that, The connector (24) extends along the thickness direction of the top cover assembly (2). The direction perpendicular to the thickness direction of the top cover assembly (2) is defined as the first direction. Along the first direction, the dimension a of the first connecting segment (241) satisfies: 3 mm ≤ a ≤ 10 mm, and the dimension b of the second connecting segment (242) satisfies: 3 mm < b ≤ 16 mm.

6. The battery cell according to claim 1, characterized in that, The connector (24) extends along the thickness direction of the top cover assembly (2), and the direction perpendicular to the thickness direction of the top cover assembly (2) is defined as the first direction. Along the first direction, the dimension a of the first connecting segment (241) and the dimension b of the second connecting segment (242) satisfy 0 mm < (ba) ≤ 13 mm.

7. The battery cell according to claim 1, characterized in that, Along the direction perpendicular to the thickness direction of the top cover assembly (2), the cross-sectional area m of the first connecting segment (241) satisfies: 15 mm² ≤ m ≤ 105 mm², and / or the cross-sectional area n of the second connecting segment (242) satisfies: 15 mm² < m ≤ 560 mm².

8. The battery cell according to claim 1, characterized in that, Along the thickness direction of the top cover assembly (2), the first connecting segment (241) has a size of 0.5 mm to 2.5 mm, and the second connecting segment (242) has a size of 0.5 mm to 2.5 mm.

9. The battery cell according to any one of claims 1 to 8, characterized in that, The first connecting segment (241) is connected to the light aluminum sheet (22) by a weld or integrally formed.

10. The battery cell according to any one of claims 1 to 8, characterized in that, The lower plastic (23) is integrally molded, or; The lower plastic (23) has a dimension along the length of the top cover assembly (2) that is greater than the dimension along the width of the top cover assembly (2). The lower plastic (23) includes at least a first main body (233) and a second main body (234). The first main body (233) and the second main body (234) are connected along the length of the top cover assembly (2). The first main body (233) and the second main body (234) are respectively provided with the mounting groove (231).

11. The battery cell according to claim 10, characterized in that, The mounting slot (231) includes a first mounting slot (231c) and a second mounting slot (231d). The first mounting slot (231c) is disposed on the first main body portion (233), and the second mounting slot (231d) is disposed on the second main body portion (234). Along the width direction of the battery cell, the first mounting slot (231c) penetrates the first main body portion (233), and the second mounting slot (231d) penetrates the second main body portion (234).

12. A battery device, characterized in that, The battery device includes a battery cell as described in any one of claims 1 to 11, and the battery device includes one or more of a battery module, a battery pack, and an energy storage battery.

13. An electrical appliance, characterized in that, The electrical device includes the battery device of claim 12, the battery device being used to provide electrical energy.

14. An energy storage device, characterized in that, The energy storage device includes the battery device of claim 12, the battery device being used to provide electrical energy.

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