Battery cell assembly, battery structure and electric equipment

Abstract

The utility model discloses a battery cell assembly, a battery structure and electric equipment, and relates to the technical field of batteries, and the battery cell assembly comprises a battery cell part and an electrode structure. The electrode structure is arranged on the battery core part, and the electrode structure comprises a plurality of tabs. The heights of the plurality of tabs are not completely equal, the heights are the distances of the tabs deviating from the battery cell part, and the plurality of tabs are folded and connected with one another. And the distance between the plurality of tab folding positions and the battery cell part is greater than or equal to the total thickness of the plurality of folded tabs. According to the application, the electrode structure can more easily meet the ultrasonic welding requirement, so that the overcurrent capability of the tab and the ultrasonic welding mark can be ensured, and the safety problem caused by thermal runaway is avoided.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell assembly, a battery structure and an electrical device. Background Art

[0002] As an important carrier of modern energy storage, the safety of energy storage batteries has always been the focus of the industry. In the current field of secondary battery technology, there is an important problem: the high consistency of the bare battery cell tabs.

[0003] Since all the tabs have the same height, when they are folded together, in addition to meeting the basic requirements of ultrasonic welding and bending, the staggered areas at the ends of the tabs will be more redundant.

[0004] The existence of this phenomenon not only affects the performance and stability of the battery, but may also make it difficult to meet the ultrasonic welding requirements of the electrode structure. Utility Model Content

[0005] The present application provides a battery cell assembly, a battery structure and an electrical device, which can more easily make the electrode structure meet the requirements of ultrasonic welding, thereby ensuring the current capacity of the tabs and ultrasonic weld marks and avoiding safety problems caused by thermal runaway.

[0006] In a first aspect, the present application provides a battery cell assembly, the battery cell assembly comprising a battery cell portion and an electrode structure. The electrode structure is arranged on the battery cell portion, and the electrode structure comprises a plurality of tabs.

[0007] The heights of the plurality of pole tabs are not completely equal, and the height is the distance of the pole tab away from the battery core portion, and the plurality of pole tabs are gathered together and connected to each other.

[0008] The distance between the folded positions of the plurality of pole tabs and the battery core portion is greater than or equal to the total thickness of the folded pole tabs.

[0009] In this way, the folded height of the tabs can be higher than the height of the diaphragm in the battery core, so that each tab can meet the connection requirements after folding, such as meeting the requirements of ultrasonic welding, so as to ensure the current capacity of the tabs and ultrasonic weld marks and avoid safety problems caused by thermal runaway. The above-mentioned folded position is the position where multiple tabs are completely gathered.

[0010] The battery cell assembly has a battery cell and an electrode structure. The electrode structure is arranged on the battery cell, and the electrode structure includes a plurality of tabs. These tabs can carry the current transfer inside the battery cell, and can realize the charging and discharging of the battery cell. The combination of the battery cell and the electrode structure can also be called a bare battery cell.

[0011] Specifically, the above-mentioned pole ears are not simply arranged on the battery core, but have their own height characteristics. The above-mentioned height may refer to the distance of the pole ear away from the battery core. The heights of multiple pole ears are not completely equal. Such a setting can more easily meet the welding requirements for individual pole ears. These pole ears can be cleverly gathered and connected to each other in the setting to form a stable whole, which not only ensures the stability of current transmission, but also avoids the safety hazards caused by loosening or breaking of the pole ears. Specifically, ultrasonic welding can be used for welding. Through ultrasonic welding, not only can multiple pole ears be welded and ultrasonic weld marks can be formed, but also the entire electrode structure can be stably welded to the adapter.

[0012] In some examples, in the direction in which the tab is away from the battery core portion, the electrode structure includes a converging portion and an overlapping portion in sequence, and the height of the converging portion is greater than or equal to the thickness of the overlapping portion.

[0013] The convergence part is an important part of the electrode structure, and the convergence part has a certain range in height. Generally, the height of the convergence part is set to be greater than or equal to the thickness of the overlapping part. Such a setting helps to ensure that the electrode structure has a certain bending margin, preparing for the bending of the battery cell relative to the electrode structure in the subsequent battery cell assembly. In addition, the convergence part can also ensure the stability and efficiency of the current during the transmission process, enhancing the overall stability of the electrode structure.

[0014] In some examples, the height of the convergent portion is H, 2mm≥H≥0.5mm.

[0015] As for the height of the convergence part, according to some specific examples, its height H is usually in the range of 0.5mm to 2mm, and can be specifically 1.5mm, 1mm, 0.8mm, etc. The selection of this range is based on a large amount of experimental data and engineering practice experience. Too low a height of the convergence part may result in the stability of the electrode structure when the battery cell is folded relative to the top cover as a whole, and it is not easy for the tab to break or twist and deform, and it is not easy to cause the problem of reduced current transmission efficiency after folding.

[0016] In some examples, the overlapping portion includes a first transition portion, a welding portion, and a second transition portion that are connected in sequence, a plurality of the tabs are ultrasonically welded on the welding portion and connected to a transfer sheet on the top cover, and an ultrasonic welding mark is provided on the welding portion.

[0017] The width of the first transition portion is L, the width of the welding portion is W, the width of the second transition portion is B, the width of the top cover is a, and the width of the adapter sheet is b. Wherein, L≥(ab) / 2, 10mm≥W≥4mm, and B≥0.5mm.

[0018] The first transition part is the beginning of the connection, and its width is L. When setting the width of the first transition part, the overall structure of the top cover and the adapter sheet needs to be considered to ensure a smooth transition and withstand stress changes during welding. Specifically, its width L should be greater than or equal to (ab) / 2, that is, the width of the first transition part is greater than or equal to half of the width of the top cover minus the width of the adapter sheet. This allows the ultrasonic welding position to have enough welding margin, making it less likely for the weld mark to exceed the overlapping part, ensuring the welding quality, and effectively dispersing the pressure during welding to prevent cracking or deformation of the welding part.

[0019] The welding part is the core part of the entire overlapping part, and its width is W. Ultrasonic welding is mainly performed in this part, where multiple tabs are precisely welded and connected to the adapter on the top cover. In order to ensure the welding quality, the width W of the welding part should be controlled between 10mm and 4mm. For example, the width of the welding part can be 5mm, 6mm, 7mm, 8mm, 9mm, 9.5mm, etc. The width within this range can not only ensure the firmness of the welding, but also avoid the low welding efficiency or unstable quality caused by excessive width.

[0020] In some examples, L+W+B≤a / 2.

[0021] The above formula corresponds to the height setting of the tab structure. When the tab height setting satisfies the above formula, it can ensure that each tab does not interfere with the tab of the opposite bare cell after being folded.

[0022] The above structure takes into account the relationship between the total width of the entire overlapping part and the width of the top cover. In order to ensure the integrity and stability of the top cover structure, the total width of L+W+B should be less than or equal to half of the top cover width a. This setting principle ensures that there is enough space in the welding area for ultrasonic welding operations, and avoids adverse effects on the overall structure of the top cover due to the overlapping part being too wide.

[0023] In some examples, the first transition portion has a bending margin relative to the adapter sheet, and the thickness of the adapter sheet is c, wherein L>c.

[0024] In this way, the first transition portion can have a sufficient bending margin, so that the battery core portion can be bent appropriately.

[0025] In some actual manufacturing and application examples, the optimization of the transition setting and bending margin of the battery cell is more important. After the width of the first transition portion is limited to a certain extent, the first transition portion can have a certain bending margin relative to the adapter. This setting can ensure that the battery cell has sufficient flexibility and adaptability when facing bending requirements, thereby avoiding unnecessary damage or deformation during the bending process.

[0026] Specifically, the width of the first transition portion is L, and the thickness of the adapter is c. It is worth noting that in order to ensure that the first transition portion can be bent smoothly and meet the bending requirements of the battery cell in practical applications, its width L needs to be greater than the thickness c of the adapter, that is, L>c. This setting fully considers the combination of material mechanics and battery structure, ensuring the overall strength and stability of the battery cell while taking into account the flexibility and adaptability during bending.

[0027] In some examples, the electrode structure further includes a redundant portion, the redundant portion is disposed on a side of the overlapping portion away from the converging portion, and the plurality of electrode tabs do not completely overlap on the redundant portion.

[0028] The setting of the pole ear height can ensure that each pole ear will not overlap with the pole after being folded; the redundant part is usually arranged on the side of the overlapping part away from the converging part, and its existence is the excess part formed after multiple pole ears are converged. After the width of the redundant part is controlled, the electrode structure needs to be reduced and then the secondary cutting or folding process can be reduced, thereby reducing the processing steps of the battery cell components and reducing the processing cost.

[0029] In some examples, the adapter is connected to a pole, a width of the pole is d, a width of the redundant portion is R, and L+W+B+R≤(ad) / 2.

[0030] The above formula corresponds to the height setting of the further ear structure. At this time, when the ear height satisfies the above formula, it can ensure that each ear does not overlap with the pole after being folded. After the width of the redundant part is limited, the redundant part can be kept away from the fuse part on the adapter, and a certain interval is generated to avoid the redundant part overlapping with the pole to form a loop after the fuse part is melted and disconnected by a large current. In this way, it can be avoided that the redundant part will form a large current again, causing high temperature to damage the pole sealing structure, thereby avoiding leakage of the pole or fire and explosion.

[0031] In a second aspect, the present application provides a battery structure, including a shell and a battery cell assembly as described above, wherein the battery cell assembly is arranged in the shell.

[0032] The battery structure can ensure that each tab can meet the connection requirements after being folded, such as meeting the ultrasonic welding requirements, so as to ensure the current capacity of the tab and the ultrasonic weld mark and avoid safety problems caused by thermal runaway. The battery structure can be used in electrical devices such as vehicles, ships or aircraft, but is not limited to it.

[0033] In a third aspect, the present application provides an electrical device, comprising a battery structure and a device body as described above, wherein the battery structure is arranged on the device body.

[0034] The power consumption setting of the battery structure of the present application can make each tab meet the connection requirements after being folded, such as meeting the ultrasonic welding requirements, so as to ensure the current capacity of the tab and the ultrasonic weld mark and avoid safety problems caused by thermal runaway. The power consumption device can be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, and the like. Among them, the electric toy can include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like, and the spacecraft can include an airplane, a rocket, a space shuttle, and a spacecraft, and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings required for use in the examples or prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some examples of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 This is a schematic diagram of the structure of an electrical device in an example of this application;

[0037] Figure 2 It is a schematic diagram of the structure after the two electrode structures interfere with each other during the process of connecting two battery cell assemblies to the top cover in the prior art;

[0038] Figure 3 This is a schematic diagram of the structure of a battery cell assembly in an example of the present application;

[0039] Figure 4 In this application example Figure 3 A partial enlarged schematic diagram of the electrode structure in the battery cell assembly at center A;

[0040] Figure 5 This is a schematic diagram of the structure in which two electrode structures do not interfere with each other during the process of connecting two battery cell assemblies to the top cover in an example of the present application;

[0041] Figure 6 This is another structural schematic diagram of two battery cell assemblies in an example of the present application after the two electrode structures do not interfere with each other during the process of connecting the two battery cell assemblies to the top cover;

[0042] Figure 7 This is a partial enlarged schematic diagram of two electrode structures in an example of the present application without mutual interference;

[0043] Figure 8 This is a schematic diagram of the structure of a battery cell assembly in another example of the present application;

[0044] Fig. 9 In another example of this application Figure 8 A partial enlarged schematic diagram of the electrode structure in the battery cell assembly at B in the middle;

[0045] Fig.10 This is a schematic diagram of the structure in another example of the present application after two electrode structures do not interfere with each other during the process of connecting two battery cell assemblies to the top cover;

[0046] Fig.11 This is another structural schematic diagram of another example of the present application in which two battery cell assemblies are connected to the top cover without the two electrode structures interfering with each other and the redundant part and the pole are spaced apart;

[0047] Fig.12 This is a partial enlarged schematic diagram of another example of the present application in which two electrode structures do not interfere with each other and the redundant part and the pole are spaced apart.

[0048] Reference numerals:

[0049] 1000, electrical equipment; 1100, battery structure; 1200, controller; 1300, motor;

[0050] 100, battery cell assembly; 110, battery cell part; 120, electrode structure; 121, convergence part; 122, first transition part; 123, welding part; 1231, ultrasonic weld; 124, second transition part; 125, redundant part; 200, top cover; 210, adapter; 211, fuse part; 220, pole. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific examples described here are only used to explain the present application and are not used to limit the present application.

[0052] As an important carrier of modern energy storage, the safety of energy storage batteries has always been the focus of the industry. In the current field of secondary battery technology, there is an important problem: the high consistency of the bare battery cell tabs.

[0053] Since all the tabs have the same height, when they are folded together, in addition to meeting the basic requirements of ultrasonic welding and bending, the staggered areas at the ends of the tabs will be more redundant.

[0054] The existence of this phenomenon not only affects the performance and stability of the battery, but may also lead to a series of other problems.

[0055] There are too many redundant staggered areas formed after the equal-height tabs are gathered together, which are easy to interfere with the tabs of the opposite bare cell (refer to Figure 2). This interference will directly affect the effect of ultrasonic welding and may cause the tab to rupture. Once the tab ruptures, the battery's current capacity will be seriously affected, causing the battery to heat up quickly during operation, thus causing thermal runaway problems. Thermal runaway not only affects battery performance, but may also threaten battery safety.

[0056] The existence of the staggered redundant area will also affect the internal resistance of the battery. When the pole ear interferes with the pole ear of the opposite bare cell, the conductivity of the battery will be hindered, resulting in a larger internal resistance. The increase in internal resistance will not only reduce the energy utilization efficiency of the cell, but also increase the energy loss of the battery during operation and reduce the battery life.

[0057] During the short-circuit test, if the fuse blows, the redundant misalignment area of ​​the tab will overlap the pole again, which will also cause thermal runaway. Short-circuit testing is an important means of testing battery safety performance, and the existence of redundant misalignment areas of the tab undoubtedly increases the risk of testing.

[0058] Moreover, the above-mentioned problems make it difficult to meet the ultrasonic welding requirements of the electrode structure.

[0059] In view of the above problems, the design of the bare cell tabs of secondary batteries can be optimized. One possible solution is to adopt a tab design with unequal heights, so that the formation of staggered redundant areas can be reduced after folding. This can not only avoid mutual interference between tabs, but also improve the performance and stability of the battery.

[0060] The battery structure disclosed in the embodiment of the present application can make each tab meet the connection requirements after being folded, such as meeting the ultrasonic welding requirements, so as to ensure the current capacity of the tab and the ultrasonic weld mark and avoid safety problems caused by thermal runaway. The battery structure can be used in electrical devices such as vehicles, ships or aircraft, but is not limited to it. The electrical equipment includes the above-mentioned battery structure and the equipment body, and the battery structure is arranged in the equipment body.

[0061] The embodiment of the present application provides an electric device using a battery as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0062] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0063] Please refer to Figure 1 , Figure 1A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery structure 1100 is provided inside the vehicle 1000, and the battery structure 1100 may be provided at the bottom, head or tail of the vehicle 1000. The battery structure 1100 may be used to power the vehicle 1000, for example, the battery structure 1100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 1200 and a motor 1300, and the controller 1200 is used to control the battery structure 1100 to power the motor 1300, for example, for the starting, navigation and working power requirements of the vehicle 1000 during driving.

[0064] In some embodiments of the present application, the battery structure 1100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0065] The present application also provides a battery structure, including a shell and the above-mentioned electrode structure, and the electrode structure is arranged in the shell. By setting the electrode structure of the present application, the battery structure can have higher safety. Specifically, the redundant part in the electrode structure can be at least partially folded toward the position of the main body. Such a setting not only creates a certain gap between the redundant part and the fuse part, but also ensures the compactness of the structure. The gap formed between the folded redundant part and the fuse part can effectively avoid the situation where the redundant part will overlap with the pole structure for a second time to form a loop after the fuse part is melted and disconnected at a large current, thereby making the battery structure safer.

[0066] To solve the above technical problems, please refer to Figure 3-Figure 12 As shown, the first aspect of the present application proposes a battery cell assembly 100, which can make it easier for the electrode structure 120 to meet the ultrasonic welding requirements, thereby ensuring the current capacity of the tabs and ultrasonic weld marks 1231 and avoiding safety problems caused by thermal runaway.

[0067] In some examples, the battery cell assembly 100 includes a battery cell portion 110 and an electrode structure 120. The electrode structure 120 is disposed on the battery cell portion 110, and the electrode structure 120 includes a plurality of tabs.

[0068] The heights of the plurality of tabs are not completely equal. The height is the distance between the tabs and the battery cell portion 110. The plurality of tabs are gathered together and connected to each other.

[0069] The distance between the multiple tabs folded positions and the battery cell 110 is greater than or equal to the total thickness of the multiple tabs folded together, so that the tab folded height can be higher than the height of the diaphragm in the battery cell 110, and then each tab can meet the connection requirements after folding, such as meeting the ultrasonic welding requirements, so that the current capacity of the tabs and ultrasonic weld marks 1231 can be guaranteed, and safety problems caused by thermal runaway can be avoided. The above-mentioned folded position is the position where the multiple tabs are completely gathered.

[0070] The battery cell assembly 100 includes a battery cell 110 and an electrode structure 120. The electrode structure 120 is disposed on the battery cell 110, and the electrode structure 120 includes a plurality of tabs. These tabs can carry the current transfer inside the battery cell 110, and can realize the charging and discharging of the battery cell 110. The combination of the battery cell 110 and the electrode structure 120 can also be called a bare battery cell.

[0071] Specifically, the above-mentioned pole ears are not simply arranged on the battery cell 110, but have their own height characteristics. The above-mentioned height may refer to the distance of the pole ear away from the battery cell 110. The heights of the multiple pole ears are not completely equal. Such a setting can more easily meet the welding requirements for the individual pole ears. These pole ears can be cleverly gathered and connected to each other in the setting to form a stable whole, which not only ensures the stability of current transmission, but also avoids the safety hazards caused by loosening or breaking of the pole ears. Specifically, ultrasonic welding can be used for welding. Through ultrasonic welding, not only can multiple pole ears be welded and ultrasonic weld marks 1231 can be formed, but also the entire electrode structure 120 can be stably welded to the adapter 210.

[0072] There is a certain limit on the distance between the folded positions of the multiple tabs and the battery cell 110, and the specific distance needs to be greater than or equal to the total thickness of the folded tabs. This arrangement allows the height of the folded tabs to be higher than the diaphragm in the battery cell 110, thereby ensuring that each tab can meet various connection requirements after folding, such as ultrasonic welding. Ultrasonic welding is an efficient and reliable connection method that can firmly connect the tabs together and improve the overall performance of the battery.

[0073] In addition, this setting can also ensure the current capacity of the tabs and ultrasonic weld marks 1231, avoiding thermal runaway problems caused by excessive current. Thermal runaway is a serious problem in the field of battery safety, which may cause the battery to catch fire or even explode. Therefore, by optimizing the tab settings, the safety of the battery can be significantly improved, bringing users a more reassuring experience.

[0074] In practical applications, the battery cell assembly 100 can be installed on the top cover 200, and one top cover 200 can connect two battery cell assemblies 100 at the same time. The two battery cell assemblies 100 are two battery cell assemblies arranged opposite to each other. The two battery cell assemblies 100 correspond to two bare cells, and the two bare cells are arranged on both sides of the top cover 200 before assembly. The electrode structures 120 on the bare cells are ultrasonically welded to the adapter 210 respectively, and the adapter 210 can be welded to the corresponding pole 220 by laser welding. One adapter 210 can connect two electrode structures 120. A fuse 211 can be provided on the positive electrode sheet in the adapter 210, and the adapter 210 can be a "T"-shaped structure as a whole. After the two bare cells are connected, they can be bent oppositely to form an overall structure in which the two bare cells are arranged in parallel. At this time, the top cover 200 is arranged on one side of the two bare cells through the cover.

[0075] In the above structure, the distance between the folded positions of the multiple pole tabs and the battery core 110 is greater than or equal to the total thickness of the folded pole tabs. The folded positions may specifically be positions where the multiple pole tabs are completely gathered for the first time.

[0076] The heights of the plurality of tabs are not completely equal, which means that the heights of each tab are not completely equal when the tabs are die-cut. The specific height rule is adjusted according to actual needs, and the heights of the plurality of tabs can have a step change or a gradual change.

[0077] In some examples, in the direction in which the tab is away from the battery cell portion 110 , the electrode structure 120 includes a convergent portion 121 and an overlapping portion in sequence, and the height of the convergent portion 121 is greater than or equal to the thickness of the overlapping portion.

[0078] The convergence portion 121 is an important component of the electrode structure 120, and the convergence portion 121 has a certain range in height. Generally, the height of the convergence portion 121 is set to be greater than or equal to the thickness of the overlapping portion. Such a setting helps to ensure that the electrode structure 120 has a certain bending margin, and prepares for the bending of the battery cell portion 110 relative to the electrode structure 120 in the subsequent battery cell assembly 100. In addition, the convergence portion 121 can also ensure the stability and efficiency of the current during the transmission process, and enhance the overall stability of the electrode structure 120.

[0079] In some examples, the height of the convergent portion 121 is H, 2 mm ≥ H ≥ 0.5 mm.

[0080] As for the height of the convergence portion 121, according to some specific examples, the height H is usually in the range of 0.5 mm to 2 mm, and can be specifically 1.5 mm, 1 mm, 0.8 mm, etc. The selection of this range is based on a large amount of experimental data and engineering practice experience. A too low height of the convergence portion 121 may result in the stability of the electrode structure 120 when the battery cell 110 is folded relative to the top cover 200 as a whole, and it is not easy for the tab to break or twist and deform, and it is not easy to cause the problem of reduced current transmission efficiency after folding.

[0081] If the height of the convergent portion 121 is too high, the margin will be too large, and part of the electrode structure 120 will bulge out after being bent. The bulging part is easily worn and creates a safety hazard, affecting the structural stability of the entire battery cell assembly 100, and may increase the manufacturing difficulty and cost of the electrode structure 120. Therefore, within this reasonable range, the height of the convergent portion 121 can fully meet the performance requirements of the electrode structure 120.

[0082] In addition to the height of the converging portion 121, the thickness of the overlapping portion is also one of the key factors to be considered in the setting of the electrode structure 120. The thickness of the overlapping portion is crucial to ensure the continuity and stability of current transmission. During the manufacturing process of the electrode structure 120, the thickness of the overlapping portion can be precisely controlled to ensure that it matches the height of the converging portion 121, thereby achieving efficient transmission of current. The thickness of the overlapping portion is based on the thickness of a single pole ear. The thickness of the overlapping portion can specifically be the cumulative thickness after multiple pole ears are stacked. A certain gap will be generated between two adjacent pole ears during the cumulative overlapping process, which increases the thickness of the overlapping portion to a certain extent. The thickness of the overlapping portion is greater than the sum of the thicknesses of multiple pole ears. Multiple pole ears can be welded together by ultrasonic welding, and an ultrasonic weld mark 1231 is formed on the surface.

[0083] In some examples, in order to better meet the welding requirements of ultrasonic welding, the overlapping portion includes a first transition portion 122, a welding portion 123, and a second transition portion 124 connected in sequence, a plurality of tabs are ultrasonically welded on the welding portion 123 and connected to the adapter plate 210 on the top cover 200, and an ultrasonic weld mark 1231 is provided on the welding portion 123.

[0084] The width of the first transition portion 122 is L, the width of the welding portion 123 is W, the width of the second transition portion 124 is B, the width of the top cover 200 is a, and the width of the adapter 210 is b. Among them, L≥(ab) / 2, 10mm≥W≥4mm, B≥0.5mm. The above width refers to the relative width of the corresponding parts of the first transition portion 122, the welding portion 123 and the second transition portion 124 in the direction in which the tab is away from the battery cell 110.

[0085] The first transition portion 122 is the beginning of the connection, and its width is L. When setting the width of the first transition portion 122, it is necessary to consider the overall structure of the top cover 200 and the adapter sheet 210 to ensure a smooth transition and withstand stress changes during the welding process. Specifically, its width L should be greater than or equal to (ab) / 2, that is, the width of the first transition portion 122 is greater than or equal to the width of the top cover 200 minus half of the width of the adapter sheet 210. In this way, sufficient welding margins can be left at the ultrasonic welding position, and it is less likely that the weld mark will exceed the overlapping part, thereby ensuring the welding quality, and effectively dispersing the pressure during the welding process to prevent cracking or deformation at the welding portion 123.

[0086] The welding part 123 is the core part of the entire overlapping part, and has a width of W. Ultrasonic welding is mainly performed in this part, where multiple tabs are precisely welded and connected to the adapter 210 on the top cover 200. In order to ensure the welding quality, the width W of the welding part 123 should be controlled between 10 mm and 4 mm. For example, the width of the welding part 123 can be 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 9.5 mm, etc. The width within this range can not only ensure the firmness of the welding, but also avoid the low welding efficiency or unstable quality caused by excessive width.

[0087] The second transition portion 124, whose width is B, plays a role of connection and buffering. This part is not directly involved in welding, but its existence is crucial to the stability and reliability of the overall structure. Therefore, the width B of the second transition portion 124 should be greater than or equal to 0.5 mm to ensure sufficient welding allowance and reduce the product yield of ultrasonic welding.

[0088] In some examples, L+W+B≤a / 2. The above formula corresponds to the height setting of the tab structure. When the tab height setting satisfies the above formula, it can be ensured that each tab does not interfere with the tab of the opposite bare cell after being folded.

[0089] The above structure takes into account the relationship between the total width of the entire overlapping portion and the width of the top cover 200. In order to ensure the integrity and stability of the top cover 200 structure, it is required that the total width of L+W+B should be less than or equal to half of the width a of the top cover 200. This setting principle ensures that there is enough space in the welding area for ultrasonic welding operations, and avoids adverse effects on the overall structure of the top cover 200 due to the overlapping portion being too wide.

[0090] Through the above settings, an overlapping part that can meet the requirements of ultrasonic welding and has good stability and reliability is successfully constructed. The overlapping part can provide strong support for the further development and application of ultrasonic welding technology.

[0091] As a precision welding technology, the welding quality of ultrasonic welding is not only affected by the overlapping structure, but also closely related to many factors such as welding equipment, welding parameters, welding environment, etc. Therefore, in practical applications, it is necessary to fine-tune and optimize the welding process according to specific conditions to ensure the best welding quality.

[0092] By rationally setting the structure of the overlapping part and strictly controlling various factors in the welding process, we can achieve efficient, stable and reliable ultrasonic welding operations and provide high-quality welding solutions for various application scenarios.

[0093] In some examples, the first transition portion 122 has a bending margin relative to the adapter sheet 210, the width of the first transition portion 122 is L, the thickness of the adapter sheet 210 is c, where L>c. This allows the first transition portion 122 to have sufficient bending margin, allowing the battery cell 110 to be properly bent.

[0094] In some actual manufacturing and application examples, the optimization of the transition setting and bending margin of the battery cell is more important. After the width of the first transition portion 122 is limited to a certain extent, the first transition portion 122 can have a certain bending margin relative to the adapter 210. This setting can ensure that the battery cell has sufficient flexibility and adaptability when facing bending requirements, thereby avoiding unnecessary damage or deformation during the bending process.

[0095] Specifically, the width of the first transition portion 122 is L, and the thickness of the adapter sheet 210 is c. It is worth noting that in order to ensure that the first transition portion 122 can be bent smoothly and meet the bending requirements of the battery cell 110 in practical applications, its width L needs to be greater than the thickness c of the adapter sheet 210, that is, L>c. This setting fully considers the combination of material mechanics and battery structure, which not only ensures the overall strength and stability of the battery cell, but also takes into account the flexibility and adaptability when bending.

[0096] In practical applications, this arrangement can effectively improve the bending performance of the battery cell assembly 100. When the battery cell portion 110 in the battery cell assembly 100 needs to be bent, the first transition portion 122 can use its sufficient bending margin to allow the battery cell to be bent smoothly without causing structural damage or performance degradation due to excessive bending.

[0097] In addition, this setting can also be flexibly adjusted according to actual needs. For example, in different application scenarios, the bending angle and bending times of the battery cell may be different. Therefore, the width L of the first transition portion 122 and the thickness c of the adapter sheet 210 can be adjusted to adapt to different bending requirements. In this way, the structural setting of the battery cell can be optimized according to actual needs to improve its performance.

[0098] In summary, by reasonably setting the bending margin of the first transition portion 122 and fully considering the relationship between it and the adapter sheet 210, the bending performance and service life of the battery cell can be effectively improved. In addition, by setting the bending margin on the first transition portion 122, the wall welding portion 123 can be bent to ensure the stability and reliability of ultrasonic welding.

[0099] In some examples, the electrode structure 120 further includes a redundant portion 125 , which is disposed on a side of the overlapping portion away from the converging portion 121 , and the plurality of electrode tabs do not completely overlap on the redundant portion 125 .

[0100] The setting of the pole ear height can ensure that each pole ear will not overlap with the pole column 220 after being folded; the redundant part 125 is usually arranged on the side of the overlapping part away from the converging part 121, and its existence is the redundant part formed after multiple pole ears are converged. After the width of the redundant part 125 is controlled, the process of secondary cutting or folding of the electrode structure 120 can be reduced, thereby reducing the processing steps of the battery cell assembly 100 and reducing the processing cost.

[0101] In some examples, the adapter 210 is connected to the pole 220 , the width of the pole 220 is d, the width of the redundant portion 125 is R, and L+W+B+R≤(ad) / 2.

[0102] The above formula corresponds to the height setting of the further tab structure. At this time, when the tab height satisfies the above formula, it can be ensured that each tab does not overlap with the pole 220 after being folded. After the width of the redundant part 125 is limited, the redundant part 125 can be kept away from the fuse part 211 on the adapter 210, and a certain interval is generated to avoid the redundant part 125 from overlapping with the pole 220 to form a loop after the fuse part 211 is melted and disconnected by a large current. In this way, it can be avoided that the redundant part 125 forms a large current again, causing high temperature to damage the sealing structure of the pole 220, thereby avoiding leakage or fire and explosion of the pole 220.

[0103] By setting the electrode structure 120 of the present application, the following effects can be achieved:

[0104] It can avoid the interference welding fracture of the opposite tabs, ensure the current capacity of the tabs and weld marks, and avoid safety problems caused by thermal runaway;

[0105] It can avoid the interference welding fracture of the opposite pole ears, effectively reduce the internal resistance of the battery cell, and improve the energy utilization efficiency of the battery cell;

[0106] This can prevent the terminal ear from overlapping with the pole 220 after the fuse (fusing part 211) burns out when the battery cell is short-circuited, causing thermal runaway of the battery cell.

[0107] The same or similar numbers in the drawings of this application correspond to the same or similar parts; in the description of this application, it should be understood that if the terms "upper", "lower", "left", "right", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings. This is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0108] The above are only preferred examples of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A battery cell assembly, characterized in that: The battery core assembly comprises: Battery cell department; An electrode structure, disposed on the battery core, the electrode structure comprising a plurality of tabs; The heights of the plurality of tabs are not completely equal, the height being the distance between the tab and the battery core, and the plurality of tabs are gathered and connected to each other; The distance between the folded positions of the plurality of pole tabs and the battery core portion is greater than or equal to the total thickness of the folded pole tabs.

2. The battery cell assembly according to claim 1, characterized in that: In the direction in which the electrode tab is away from the battery core portion, the electrode structure includes a convergent portion and an overlapping portion in sequence, and the height of the convergent portion is greater than or equal to the thickness of the overlapping portion.

3. The battery cell assembly according to claim 2, characterized in that: The height of the convergent portion is H, 2mm≥H≥0.5mm.

4. The battery cell assembly according to claim 2, characterized in that: The overlapping portion includes a first transition portion, a welding portion, and a second transition portion connected in sequence, a plurality of the tabs are ultrasonically welded on the welding portion and connected to the adapter sheet on the top cover, and an ultrasonic welding mark is provided on the welding portion; The width of the first transition portion is L, the width of the welding portion is W, the width of the second transition portion is B, the width of the top cover is a, and the width of the adapter plate is b; wherein, L≥(ab) / 2, 10mm≥W≥4mm, and B≥0.5mm.

5. The battery cell assembly according to claim 4, characterized in that: L+W+B≤a / 2.

6. The battery cell assembly according to claim 5, characterized in that: The first transition portion has a bending margin relative to the adapter sheet, and the thickness of the adapter sheet is c, wherein L>c.

7. The battery cell assembly according to claim 4, characterized in that: The electrode structure further includes a redundant portion, which is disposed on a side of the overlapping portion away from the converging portion, and the plurality of electrode tabs do not completely overlap on the redundant portion.

8. The battery cell assembly according to claim 7, characterized in that: The adapter is connected to a pole, the width of the pole is d, the width of the redundant portion is R, and L+W+B+R≤(ad) / 2.

9. A battery structure, characterized in that: include: case; The battery cell assembly according to any one of claims 1 to 8, wherein the battery cell assembly is arranged in the shell.

10. An electrical device, characterized in that: include: The battery structure as claimed in claim 9; and, The device body is provided with the battery structure.

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