Battery device

Abstract

The invention relates to the technical field of batteries, in particular to a battery device which comprises a shell, a battery module and a battery module, the pole column is arranged on the shell; the battery cell is arranged in the shell; the battery core comprises a tab part, the tab part is provided with a plurality of tabs, one end of each tab is connected with the battery core to form a leading-out end, the other end of each tab is directly connected with the pole to form a first area, each tab is provided with a fusing part, and the fusing parts are located between the first areas and the leading-out ends. According to the embodiment of the invention, the time difference of current transmission on each tab and the fusing sensitivity can be effectively balanced, the tabs of the fusing part are ensured to be synchronously fused when the current is abnormal, and the risk of fusing protection failure caused by the fact that part of the tabs are not fused is avoided. And the tab part can be prevented from being fused in a plurality of areas, so that the risk of overlapping with the shell and the battery cell of the battery device is reduced.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more specifically to a battery device. Background Technology

[0002] In traditional batteries, adapter plates are typically welded to the tabs and terminals separately to achieve stable current conduction. Currently, in order to save space occupied by adapter plates and improve the internal space utilization of the battery, some batteries directly weld the tabs and terminals.

[0003] However, in traditional batteries, the fuse is located on the adapter plate, where a narrow structure is designed to achieve overcurrent fusing. In current designs that directly connect the tabs to the terminals, the fuse needs to be moved to the tabs. However, with a large number of tabs, they need to be folded together before welding to the terminals. In the thickness direction of the cell, the tabs are generally folded together in the middle or on one side of the cell. If the tabs are folded together on one side, the length differences between the tabs and the fuse can be significant, leading to inconsistent fusing between shorter and longer tab areas. For example, shorter tab areas may fuse faster, while longer tab areas may fuse slower or not at all, resulting in incomplete fusing.

[0004] This results in some batteries having a situation where all the tabs in the fuse section do not completely melt, thus failing to protect the battery. Summary of the Invention

[0005] In view of this, the present invention provides a battery device to solve the problem that not all the tabs of the fuse part are completely melted, thus failing to protect the battery.

[0006] In a first aspect, the present invention provides a battery device comprising:

[0007] case;

[0008] The pole post is disposed on the housing;

[0009] A battery cell is disposed within the housing; the battery cell includes a tab portion, the tab portion is provided with multiple tabs, one end of the tab is connected to the battery cell to form a lead-out end, the other end of the tab is directly connected to the terminal post to form a first region, the tab is provided with a fuse portion, the fuse portion is located between the first region and the lead-out end.

[0010] Beneficial Effects: When the length difference between the tabs and the fuse section is large, the fusing effect in the fusing area is poor, and adhesion is prone to occur, leading to a short circuit risk. This embodiment, by setting a fuse section, ensures that when the battery current is large and triggers the fuse protection function, fusing occurs in the same area as much as possible. Simultaneously, this embodiment effectively balances the time difference of current transmission on each tab and the fusing sensitivity, ensuring that the tabs in the fuse section fuse synchronously when the current is abnormal, avoiding the risk of fuse protection failure due to some tabs not fusing. Furthermore, it can optimize the overall structural layout of the tabs, improving the space utilization and energy density of the battery device. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the overall structure of the battery device in an embodiment of the present invention;

[0013] Figure 2 for Figure 1 A sectional view;

[0014] Figure 3 for Figure 2 A magnified view of part A in the middle;

[0015] Figure 4 This is a schematic diagram of the electrode structure in an embodiment of the present invention;

[0016] Figure 5 This is a schematic diagram of the structure of the upper electrode tab of the battery cell in an embodiment of the present invention;

[0017] Figure 6 This is a schematic diagram of the tabs after they have been unfolded in an embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures:

[0019] 1. Pole post;

[0020] 2. Battery cell; 21. Electrode tab; 22. Folding position; 221. Fuse section; 222. First zone; 223. Pre-welded section;

[0021] 3. Shell. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used for the convenience of describing the invention and for simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes and should not be construed as indicating or implying relative importance.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0026] The batteries disclosed in this application may be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc., and are not limited thereto.

[0027] A single battery cell typically includes a casing, a cell 2, an adapter plate, and an electrolyte. The casing is used to house the cell 2 and the electrolyte, and generally includes a housing 3 and a cover. At least one positive electrode post and at least one negative electrode post are disposed on the housing 3 and / or the cover. The cell 2 includes one or more electrode assemblies, which are formed by stacking or winding positive electrode plates, negative electrode plates, and separators. The separator is located between adjacent positive and negative electrode plates to insulate them. At least one end of the electrode assembly has a tab 21. One end of the adapter plate is electrically connected to the tab 21, and the other end is electrically connected to the electrode post 1.

[0028] To prevent the risk of overheating and fire in the battery, a fuse 221 is provided on the tab 21. The fuse 221 is usually formed by cutting through holes or notches in the tab 21 to increase its resistance. When the battery experiences a short circuit or an abnormal increase in current, the fuse 221 will melt quickly due to overheating, thus providing overcurrent protection.

[0029] Taking the wound cell 2 as an example, the specific preparation process is as follows: the positive electrode sheet, negative electrode sheet and separator are wound to form an electrode assembly, and a tab 21 is led out from one end of the electrode assembly. When the tab 21 is fixed with the adapter plate, the electrode assembly and the tab 21 are first placed along the direction of the tab 21. Then the tab 21 of the electrode assembly is welded to the tab 21 welding area of ​​the adapter plate. Then the adapter plate and the pole post 1 on the cover plate are welded to the pole post 1 welding area of ​​the adapter plate. After the welding is completed, the pole post 1 and the tab 21 are located on the same side in the thickness direction of the adapter plate. Then the electrode assembly is folded along the connection position of the tab 21 and the electrode assembly, so that the electrode assembly and the pole post 1 are located on both sides in the thickness direction of the adapter plate. The folded electrode assembly is put into the shell, and the cover plate is welded and sealed to the battery shell 3 body. Liquid is injected, formation is performed, and the liquid injection hole is sealed to obtain a single cell.

[0030] The following is combined with Figures 1 to 6 The following describes embodiments of the present invention.

[0031] According to an embodiment of the present invention, a battery device is provided, the battery device comprising: a housing 3, terminals 1, and a battery cell 2.

[0032] Specifically, in this embodiment, a pole post 1 is provided on the housing 3. For the installation method of the pole post 1, a cover plate can be provided on the housing 3, and the cover plate has mounting holes for installing the pole post 1. The electrode lug 31 passes through the mounting holes and connects to the pole post 1. Then, the pole post 1 is welded to the mounting holes on the cover plate, thereby completing the fixation of the pole post 1, the cover, and the housing 3. Of course, this embodiment is merely an example and is not intended to limit the scope. Those skilled in the art can modify it according to actual circumstances, as long as the same technical effect is achieved.

[0033] Furthermore, in this embodiment, a receiving cavity is provided inside the housing 3, and the battery cell 2 is disposed in the receiving cavity. Multiple battery cells 2 can be disposed within the battery device; of course, those skilled in the art can adjust the number of battery cells 2 according to actual conditions. Further, the battery cell 2 includes a tab portion, which is provided with multiple tabs 21. One end of each tab 21 is connected to the battery cell 2 to form a lead-out end, and the other end of each tab 21 is directly connected to the terminal post 1 to form a first region 222. Each tab 21 is provided with a fusible part 221, which is located between the first region 222 and the lead-out end.

[0034] When the length difference between the tab 21 and the fuse section 221 is large, the fusing effect in the fusing area is poor, and adhesion is prone to occur, leading to a short circuit risk. This embodiment, by setting the fuse section 221, ensures that when the battery current is large and triggers the fuse protection function, fusing occurs in the same area as much as possible. Simultaneously, this embodiment effectively balances the time difference of current transmission on each tab 21 with the fusing sensitivity, ensuring that the tabs 21 of the fuse section 221 fuse synchronously when the current is abnormal, avoiding the risk of fuse protection failure due to some tabs 21 not fusing. Furthermore, it can optimize the overall structural layout of the tabs 21, improving the space utilization and energy density of the battery device.

[0035] Furthermore, in an optional embodiment, along the extension direction of the tab 21, that is, from the cell 2 to the terminal post 1, the minimum distance between the plurality of tabs 21 and the fuse portion 221 and the cell 2 is a first distance L1, and the maximum distance between the plurality of tabs 21 and the fuse portion 221 and the cell 2 is a second distance L2.

[0036] Since the tabs 21 are all distributed on the top edge of the cell 2 near the terminal post 1, the tabs 21 and the fuse part 221 form a triangular shape. Therefore, the length between the tabs 21 on both sides of the cell 2 and the fuse part 221 is the longest, and the length between the tabs 21 on the center line of the cell 2 and the fuse part 221 is the shortest.

[0037] Furthermore, in this embodiment, along the width direction of the tab 21, that is, in the direction perpendicular to the extension of the tab 21, the width of the fuse portion 221 is the first width X, and the width of the root of the tab 21, that is, the part where the tab 21 is connected to the battery cell 2, near the end of the battery cell 2 is the second width Y.

[0038] Furthermore, in this embodiment, (L2-L1)*X / Y is between 0.2 and 3.5.

[0039] For example, the values ​​could be 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.5, etc. Of course, this embodiment is merely an example illustrating specific values ​​within this range, and does not impose any limitations. Those skilled in the art can modify the values ​​according to actual circumstances, as long as the same technical effect is achieved.

[0040] This embodiment, by setting the fuse section 221, ensures that when the battery current is large and triggers the fuse protection function, the fuse will blow in the same area as much as possible. Simultaneously, this embodiment limits the parameter range of (L2-L1)*X / Y, which effectively balances the time difference of current transmission on each tab 21 and the fuse sensitivity, ensuring that the tabs 21 of the fuse section 221 blow synchronously when the current is abnormal, avoiding the risk of fuse protection failure due to some tabs 21 not blowing. Furthermore, it can also optimize the overall structural layout of the tabs 21, improving the space utilization and energy density of the battery device.

[0041] Furthermore, in an optional embodiment, the difference between the second distance L2 and the first distance L1 is between 3mm and 15mm. Of course, the first distance L1 and the second distance L2 are due to the different retraction positions 22 when the tabs 21 are retracted, resulting in differences in the arrangement positions of the tabs 21, thus forming the longest and shortest tab 21 paths.

[0042] For example, the values ​​could be 3mm, 4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 15mm, etc. Of course, this embodiment is merely an example illustrating specific values ​​within this range, but it does not impose limitations. Those skilled in the art can modify the values ​​according to actual circumstances, as long as the same technical effect is achieved.

[0043] Normally, all tabs 21 have the same unfolded length. When the folded position 22 is located on one side of the cell 2, the distance between the tab 21 on that side of the cell 2 and the folded position 22 is the shortest. Conversely, the distance between the tab 21 on the other side of the cell 2 and the folded position 22 is the longest. In other words, the tab 21 on the cell 2 directly opposite the folded position 22 is the shortest, and the tab 21 furthest from the folded position 22 is the longest.

[0044] Based on this, limiting the difference between the second distance L2 and the first distance L1 to a certain range can ensure that the closing position 22 is in a suitable position, so as to minimize the distance difference between each tab 21 and the fuse part 221, thereby reducing the time difference of current transmission to the fuse part 221.

[0045] With this configuration, this embodiment can reduce the current transmission time difference caused by the difference in length of the tabs 21 by limiting the range of the difference between the second distance L2 and the first distance L1. This reduces the risk that the shorter tab 21 will melt first and the longer tab 21 will not melt completely within the same time period. To a certain extent, this can improve the synchronization rate of melting and ensure that the battery protection function can reliably take effect under abnormal current.

[0046] Furthermore, in one optional embodiment, the ratio between the first width X and the second width Y is between 0.05 and 0.25. If the ratio is too large, it indicates that the width of the fuse part 221 is large, resulting in an excessively strong current-carrying capacity of the fuse part 221, requiring a larger current to fuse, thus causing protection hysteresis. If the ratio is too small, it indicates that the width of the fuse part 221 is small, resulting in an excessively high resistance of the fuse part 221, which is prone to overheating during normal operation and easily leads to abnormal fuse failure.

[0047] For example, the values ​​could be 0.05, 0.06, 0.08, 0.1, 0.12, 0.14, 0.16, 0.18, 0.2, 0.22, 0.24, 0.25, etc. Of course, this embodiment is merely an example illustrating specific values ​​within this range, and does not impose any limitations. Those skilled in the art can modify the values ​​according to actual circumstances, as long as the same technical effect is achieved.

[0048] This configuration, limiting the ratio range of the first width X to the second width Y in this embodiment, effectively balances the overcurrent capability and sensitivity of the fuse section 221. This avoids the problem of excessively large widths leading to excessively high current thresholds and high fuse thresholds, resulting in protection lag, while also preventing excessively small widths from causing abnormal fuse failures during normal operation. Therefore, it ensures stable operation of the battery device under normal conditions and rapid response under abnormal currents, improving the overall safety of the battery device.

[0049] Furthermore, in an alternative embodiment, the tab 21 is folded back along the centerline of the battery cell 2.

[0050] Furthermore, in an optional embodiment, along the thickness direction of the battery cell 2, the tab 21 is gathered to one side of the battery cell 2, and (L2-L1)*X / Y is between 0.2 and 3.

[0051] For example, it could be 0.2, 0.22, 0.24, 0.26, 0.28, 0.3, etc. Of course, this embodiment is merely an example of specific values ​​within this range, but it does not limit the scope. Those skilled in the art can make changes according to actual circumstances, as long as the same technical effect is achieved.

[0052] With this configuration, the tabs 21 are gathered at the center line or side of the cell 2, allowing technicians to flexibly optimize the tab layout according to the internal space requirements of the battery. When the gathering position 22 is set at the center line of the cell 2, the overall length requirement of the tabs 21 can be reduced, avoiding redundancy in the overall structure and excessive space occupation within the battery device due to the tabs 21 being too long. When the gathering position 22 is set at the side of the cell 2, the space occupied in the middle of the cell 2 can be reduced, thereby improving the compactness of the tab arrangement and increasing the space utilization rate in the middle of the cell 2.

[0053] Furthermore, in an optional embodiment, the tab 21 located between the first region 222 and the lead-out end forms at least one bent section. For example, two bent sections, three bent sections, four bent sections, etc., can be provided depending on the internal structure of the battery. Of course, this embodiment is merely an example illustrating the number of bends of the tab 21 when it is folded up, but it is not a limitation. Those skilled in the art can adjust it according to the actual situation, as long as the same technical effect can be achieved.

[0054] With this configuration, the tab 21 is bent at least once in this embodiment, which can adapt to the height and orientation limitations inside the battery. By adjusting the extension path of the tab 21 through bending, interference with other components is avoided, further optimizing space utilization. At the same time, the actual length of the tab 21 can be adjusted according to the actual height inside the battery, so that the tab 21 has sufficient redundant length to avoid tearing during installation and use.

[0055] Furthermore, in an optional embodiment, the tab 21 on each cell 2 located between the first region 222 and the lead-out end forms a bent section, and the bent section forms a C-shaped structure. The bending direction can be either towards one side of the cell 2 or towards the other side of the cell 2, and the direction of the tab 21 can be adjusted with only one bend.

[0056] With this design, the tab 21 is bent once to form a C-shaped structure, which facilitates operation by technicians and simplifies the overall structure of the tab 21. The redundant length is moderate, allowing for directional convergence of the tab 21 within a limited space, reducing bending stress concentration, lowering the risk of tab 21 breakage, and facilitating subsequent welding operations. Furthermore, it promotes heat dissipation from the tab 21, making the fused portion 221 less prone to abnormal melting.

[0057] Furthermore, in an optional embodiment, the tab 21 on each cell 2, located between the first region 222 and the lead-out end, forms two bent sections. These two bent sections form an S-shaped structure, i.e., two reverse bends are performed. This allows for more complex path adjustments, improves spatial adaptability, and increases the redundancy length of the tab 21. Additionally, it reduces the difference between the second distance L2 and the first distance L1, resulting in better fusing performance and reducing the likelihood of adhesion.

[0058] With this configuration, the tab 21 is bent twice to form an S-shaped structure. The extension direction of the tab 21 can be further adjusted through multiple bends to adapt to the more complex spatial layout inside the battery, improve design flexibility, disperse bending stress, retain sufficient redundant length, reduce the risk of the tab 21 tearing caused by continuous vibration of the battery during use, and thus improve the durability of the tab 21.

[0059] Furthermore, in an optional embodiment, along the extending direction of the tab 21, a first region 222 is provided on the side of the tab 21 near the terminal post 1. The first region 222 is welded to the terminal post 1 by laser welding, thereby connecting the tab 21 and the terminal post 1. The area of ​​the first region 222 directly affects the overcurrent effect of the battery.

[0060] Furthermore, a fuse 221 is provided at the closing position 22, that is, the fuse 221 and the first area 222 are provided separately so that the two do not affect each other as much as possible.

[0061] With this configuration, the first zone 222 is close to the pole post 1 and the fusing part 221 is far away from the pole post 1. This can separate the high-heat first zone 222 from the fusing part 221, preventing heat from being conducted to the fusing part 221 during the welding process and causing abnormal fusing. This ensures that the fusing part 221 will only trigger the fusing function under the preset current threshold.

[0062] Furthermore, in an optional embodiment, the extension distance of the tab 21 between the first region 222 and the fuse portion 221 is a third distance L3, which is between 2 mm and 15 mm.

[0063] For example, the values ​​could be 2mm, 3mm, 4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 15mm, etc. Of course, this embodiment is merely an example illustrating specific values ​​within this range, but it does not impose limitations. Those skilled in the art can modify the values ​​according to actual circumstances, as long as the same technical effect is achieved.

[0064] With this configuration, this embodiment defines a third distance L3 between the first zone 222 and the fusion section 221, which can further isolate the heat effects of the welding area, prevent residual welding heat from interfering with the normal operation of the fusion section 221, and ensure the temperature stability and protection accuracy of the fusion section 221.

[0065] Furthermore, in an optional embodiment, the tab 21 is provided with a pre-welded portion 223. The pre-welded portion 223 pre-fixes the dispersed tabs 21 by ultrasonic welding, which can prevent the tabs 21 from loosening during welding and ensure normal laser welding. At the same time, a portion of the pre-welded portion 223 is used as the first region 222. Therefore, the area of ​​the pre-welded portion 223 is larger than the area of ​​the first region 222, and the pre-welded portion 223 covers the first region 222 on the projection of the plane where the tab 21 is located.

[0066] With this configuration, the area of ​​the pre-welded part 223 is larger than that of the first region 222 and covers the first region 222. The dispersed tabs 21 can be fixed into a whole by ultrasonic pre-welding, thereby avoiding welding deviations caused by the loosening of the tabs 21 during welding. This improves the stability and reliability of laser welding in the first region 222 and reduces the risk of incomplete welding and missing welding to a certain extent.

[0067] Furthermore, in an optional embodiment, the fusible portion 221 is disposed within the pre-welded portion 223. The pre-welded portion 223 has fixed the electrode tab 21 by ultrasonic welding. The fusible portion 221 is located within the pre-welded portion 223, and the fixing effect of the pre-welding can be used to ensure the structural stability of the fusible portion 221, avoid the deformation caused by the loosening of the electrode tab 21, and thus facilitate the cutting and processing of the fusible portion 221.

[0068] With this configuration, the fusible link 221 is placed within the pre-welded portion 223 in this embodiment, and the structural stability of the fusible link 221 can be ensured by the fixing effect of the pre-welded portion 223. Furthermore, the pre-welded tab 21 is less prone to loosening, facilitating the cutting and processing of the fusible link 221 by technicians. Simultaneously, the better structural stability of the pre-welded portion 223 also reduces the risk of tearing of the fusible link 221 under stress.

[0069] Furthermore, in an optional embodiment, the fusing portion 221 is at least partially not provided within the pre-welded portion 223. The fusing portion 221 provided in the pre-welded portion 223 is the inner fusing portion 221, and the fusing portion 221 not provided in the pre-welded portion 223 is the outer fusing portion 221. Along the extending direction of the tab 21, the ratio of the length of the inner fusing portion 221 to the total length of the fusing portion 221 is between 0.5 and 1.

[0070] For example, it could be 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc. Of course, this embodiment is merely an example of specific values ​​within this range, but it does not limit the scope. Those skilled in the art can make changes according to actual circumstances, as long as the same technical effect is achieved.

[0071] In this embodiment, the inner fusion section 221 is pre-welded and fixed, making the structure relatively stable, and the outer fusion section 221 can flexibly adapt to the internal space requirements of the battery according to the actual situation.

[0072] With this configuration, the length ratio of the inner and outer fusible portions 221 is limited to a certain range in this embodiment. Since the portion of the fusible portion 221 within the pre-welded portion 223 is fixed by pre-welding, the structural stability of the fusible portion 221 can be guaranteed. Furthermore, it can also avoid structural loosening caused by excessive length of the outer fusible portion 221, and reduce the risk of the tab 21 falling off after melting and having to re-attach to the battery housing 3 and cell 2.

[0073] Furthermore, in an optional embodiment, along the extending direction of the tab 21, both sides of the fuse portion 221 converge inward to form an inner rounded corner structure.

[0074] With this configuration, the edges of the fuse section 221 on both sides are rounded, which reduces stress concentration caused by the traditional right angle structure compared to the traditional right angle structure. This reduces the risk of tearing of the tab 21 during bending, vibration or fuse breaking, and extends the service life of the fuse section 221, thereby ensuring the structural integrity of the tab 21 during long-term use.

[0075] Furthermore, in an optional embodiment, insulating tape is adhered to the surface of the tab 21. The insulating tape wraps around the fused portion 221, completely covering the entire surface of the fused portion 221. The insulating tape extends towards the battery cell 2 and towards the first region 222.

[0076] Of course, the insulating tape can also be extended only to one side. This embodiment is merely illustrative, and those skilled in the art can adjust it according to actual circumstances.

[0077] With this configuration, insulating tape is attached to the surface of the tab 21 in this embodiment, which can further enhance the insulation effect of the tab 21. This can prevent the tab 21 from accidentally contacting other components before melting, and can also prevent the broken part after melting from contacting the surrounding structure, such as the cell 2 and the casing 3, to form a short circuit, thereby improving the overall insulation reliability of the battery.

[0078] Furthermore, in an optional embodiment, when multiple battery cells 2 are provided, the terminal post 1 is typically positioned at the center line of the stacked battery cells 2, with the tabs 21 of each battery cell 2 converging towards the terminal post 1. For example, when two battery cells 2 are provided, the terminal post 1 is located on the extension line between the two battery cells 2; when three battery cells 2 are provided, the terminal post 1 is located on the extension line of the middle battery cell 2. In this way, the tabs 21 of each battery cell 2 will not be too long when converging, which can shorten the connection path between the tabs 21 of each battery cell 2 and the terminal post 1. At the same time, it can also avoid mutual interference caused by the tabs 21 of different battery cells 2 extending in different directions.

[0079] With this configuration, the tabs 21 of multiple battery cells 2 are brought closer to the terminal post 1. Since the terminal post 1 is usually located at the center line of the stacked battery cells 2, the connection path between the tabs 21 and the terminal post 1 in each battery cell 2 can be shortened, reducing the occupation of unused space. At the same time, it can avoid mutual interference between the tabs 21 of different battery cells 2, facilitate centralized welding, and improve production efficiency and structural stability.

[0080] The test procedure for electrode 21 fuse failure is as follows:

[0081] For each embodiment and comparative example, 100 sets of batteries were taken. The difference between the maximum distance L2 and the minimum distance L1 between the free end of the tab 21 and the fuse part 221 was set as L2-L1 according to the table below. In the width direction of the tab 21, the ratio between the width X of the fuse part 221 and the width Y at the free end of the tab 21 was X / Y. All other features were the same.

[0082] The electrode 21 with a fuse part 221 has its lead end welded to one side of the electrode post 1 on the cover plate. The second end of the electrode 21 is a free end, which is the root of the electrode 21 connected to the battery cell 2. The other side of the electrode post 1 is welded to the busbar. One of the two electrical connection interfaces of the test equipment is connected to the busbar and the other is connected to the free end of the electrode 21. After the circuit is turned on, the fuse requirement is checked under the preset current.

[0083] The testing equipment uses a current source testing device. After connecting the conductive busbar and the end of the tab 21 of the test object, power is applied and the magnitude of the applied current is adjusted until the preset fusing current is reached. It is then observed whether the fusing part 221 of the tab 21 fuses normally when the preset fusing current is applied.

[0084] If the current applied is less than the preset fusing current, the fuse 221 will fuse abnormally and be deemed unqualified.

[0085] If the current applied is equal to the preset fusing current, the fuse 221 will melt, but if the fuse 221 is stuck together, it will be deemed unqualified.

[0086] If the applied current is equal to the preset fusing current, the fuse 221 melts and there is no adhesion of the fuse 221, then it meets the product safety standards and is deemed qualified.

[0087] The pass rate is calculated as (number of qualified batteries / total number of batteries) * 100%. A pass rate of 98% or higher is considered qualified; otherwise, it is considered unqualified.

[0088]

[0089] Comparing the 7 comparative examples and 14 embodiments in the table above, it can be seen that different values ​​of (L2-L1)*X / Y can be used to determine different adhesion pass rates and abnormal melting pass rates of tab 21.

[0090] When the range of (L2-L1)*X / Y is between 0.2mm and 3.5mm, the pass rate for tab 21 adhesion is above 98%, and the pass rate for tab 21 abnormal melting is also above 98%. Therefore, when the range of (L2-L1)*X / Y is between 0.2mm and 3.5mm, the battery meets the product safety standards and is deemed qualified.

[0091] However, when the range of (L2-L1)*X / Y is less than 0.2mm, although the pass rate of tab 21 adhesion is above 98%, the pass rate of tab 21 abnormal melting is significantly lower than 98%. This shows that when (L2-L1)*X / Y is too small, it is easy to cause tab 21 abnormal melting, but it has almost no effect on the problem of tab 21 adhesion.

[0092] Furthermore, when the range of (L2-L1)*X / Y is higher than 3.5mm, although the pass rate of abnormal melting of tab 21 is above 98%, the pass rate of adhesion of tab 21 is significantly lower than 98%. This shows that when (L2-L1)*X / Y is too large, it is easy to cause tab 21 adhesion, but it has almost no impact on the problem of abnormal melting of tab 21.

[0093] In summary, when the range of (L2-L1)*X / Y is between 0.2mm and 3.5mm, the battery meets the product safety standards and has a good pass rate.

[0094] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery device, characterized by, The application relates to a battery cell, comprising: a shell (3); a pole column (1) arranged on the shell (3); a battery cell (2) arranged in the shell (3); the battery cell (2) comprises a tab part provided with a plurality of tabs (21), one end of the tab (21) is connected with the battery cell (2) to form a leading end, the other end of the tab (21) is directly connected with the pole column (1) to form a first area (222), and the tab (21) is provided with a fuse part (221) located between the first area (222) and the leading end.

2. The battery device according to claim 1, characterized by Along the extension direction of the tab (21), the minimum distance between the plurality of tabs (21) and the battery cell (2) is a first distance L1, and the maximum distance between the plurality of tabs (21) and the battery cell (2) is a second distance L2. Along the width direction of the tab (21), the width of the fuse part (221) is a first width X, and the width of the root of the tab (21) is a second width Y. And (L2-L1)*X / Y is between 0.2 and 3.

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3. The battery device of claim 2, wherein The difference between the second distance L2 and the first distance L1 is between 3 mm and 15 mm.

4. The battery device of claim 3, wherein The ratio of the first width X to the second width Y is X / Y, and the range of X / Y is between 0.05 and 0.

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5. The battery device according to any one of claims 2 to 4, characterized by, The tab (21) is gathered on the center line of the battery cell (2).

6. The battery device according to any one of claims 2 to 4, wherein Along the thickness direction of the battery cell (2), the tab (21) is gathered on one side of the battery cell (2), and (L2-L1)*X / Y is between 0.2 and 3.

7. The battery device according to any one of claims 1 to 4, characterized by The tab (21) located between the first area (222) and the leading end forms at least one bending section.

8. The battery device of claim 7, wherein, Each tab (21) located between the first area (222) and the leading end on each battery cell (2) forms one bending section, and one bending section forms a C-shaped structure; each tab (21) located between the first area (222) and the leading end on each battery cell (2) forms two bending sections, and two bending sections form an S-shaped structure.

9. The battery device according to any one of claims 1 to 4, characterized by Along the extension direction of the tab (21), the first area (222) and the pole column (1) are welded; the fuse part (221) is arranged at the gathering position (22).

10. The battery device of claim 9, wherein, The extension distance of the tab (21) between the first area (222) and the fuse part (221) is a third distance L3, and the third distance L3 is between 2 mm and 15 mm.

11. The battery device of claim 10, wherein, The tab (21) is provided with a pre-welding part (223), the area of the pre-welding part (223) is greater than the area of the first area (222), and in the projection on the plane where the tab (21) is located, the pre-welding part (223) covers the first area (222).

12. The battery device of claim 11, wherein, The fuse part (221) is arranged in the pre-welding part (223).

13. The battery device of claim 11, wherein, The fuse part (221) is at least partially not arranged in the pre-welding part (223), the fuse part (221) arranged in the pre-welding part (223) is an inner fuse part (221), and the fuse part (221) not arranged in the pre-welding part (223) is an outer fuse part (221). The ratio of the length of the inner fusing portion (221) to the total length of the fusing portion (221) is between 0.5 and 1 along the extension direction of the tab (21).

14. The battery device according to any one of claims 10 to 13, wherein Both sides of the fusing portion (221) converge inwardly to form an inner fillet structure along the extension direction of the tab (21).

15. The battery device according to any one of claims 10 to 13, wherein An insulating tape is attached to the surface of the tab (21).

16. The battery device of claim 15, wherein, The insulating tape is wrapped around the fusing portion (221) so that the insulating tape completely covers the entire surface of the fusing portion (221).

17. The battery device of claim 16, wherein, The insulating tape extends towards the direction of the battery cell (2), or / and, the insulating tape extends towards the direction of the first area (222).

18. The battery device according to any one of claims 10 to 13, wherein When multiple battery cells (2) are provided, the tabs (21) of each battery cell (2) are gathered towards the position of the pole (1).

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