Battery

Abstract

The invention belongs to the technical field of batteries, and discloses a battery, which comprises at least two pole groups, a cover plate assembly and a shell, the pole groups are electrically connected, the end parts of the pole groups are connected with tabs, the end face of one of the adjacent pole groups facing the other is connected with a first connecting part, and the other one is correspondingly connected with a second connecting part. The first connecting part and the second connecting part are clamped; the cover plate assembly comprises a cover plate body and a pole, the cover plate body is arranged at the end part of the pole group in the first direction, and the pole is arranged on the cover plate body and is connected with the tab; the shell and the cover plate body are connected and enclose to form a space for accommodating a pole group; the first direction is the height direction of the cover plate body. Therefore, by arranging the first connecting parts and the second connecting parts and mutually splicing the first connecting parts and the second connecting parts, a plurality of pole groups can be connected, the battery capacity is improved, the positions of the pole groups in the shell are limited, the space utilization rate is improved, and the battery structure is more compact.

Description

Technical Field

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

[0002] Lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage. As lithium-ion battery technology matures, the performance and safety of lithium-ion batteries are also being improved.

[0003] A lithium-ion battery includes an electrode assembly, a cover plate, and a housing. The electrode assembly is connected to tabs, and the cover plate is provided with a terminal post connected to the tabs. A rivet block is connected to the end of the terminal post away from the electrode assembly, and the rivet block and the terminal post protrude from the cover plate.

[0004] Because the cover plate in related technologies is usually a flat structure, the protruding rivet blocks and terminals occupy the space on the outside of the cover plate, which is not conducive to battery module assembly and affects the assembly rate of the module. Furthermore, the rivet blocks and terminals are prone to bumps and damage during transportation, assembly and other processes, which affects the battery safety performance. In addition, the electrode assembly is usually rectangular, the battery capacity is limited, and the gap between the end of the electrode assembly and the cover plate is large. Connecting pieces are required to connect the tabs and terminals, which increases the number of structural components and cost. The structural strength at the connection between the electrode assembly and the cover plate is low, which increases the risk of excessive movement and deformation damage of the electrode assembly when it is pushed into the casing. Summary of the Invention

[0005] The purpose of this invention is to provide a battery that solves the problems of low battery space utilization, limited capacity, and poor safety.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A battery includes: at least two electrode groups electrically connected to each other, each electrode group having a tab connected to its end, one of adjacent electrode groups having a first connecting portion connected to its end face facing the other, and the other having a corresponding second connecting portion connected, the first connecting portion and the second connecting portion being snapped together; a cover plate assembly including a cover plate body and a terminal post, the cover plate body being disposed at the end of the electrode group in a first direction, the terminal post being disposed on the cover plate body and connected to the tab; and a housing connected to the cover plate body and enclosing a space for accommodating the electrode groups; the first direction being the height direction of the cover plate body.

[0008] Preferably, the electrode assembly is further connected to a first protrusion and a second protrusion. The first protrusion is disposed on the side of the electrode assembly in a second direction, and the second protrusion is disposed at the end of the electrode assembly in the first direction. The cover plate assembly is connected to the second protrusion. In the first direction, the second protrusion protrudes from the surface of the electrode assembly and is disposed on the surface of the electrode post opposite to the surface of the electrode assembly. The second direction is the length direction of the cover plate body.

[0009] Preferably, the cover plate assembly further includes a riveting block connected to the pole post, wherein in the first direction, the second protrusion protrudes from the surface of the pole group opposite to the surface of the riveting block opposite to the pole group.

[0010] Preferably, along the first direction, the area of ​​the second protrusion away from the end of the electrode group is smaller than the area of ​​the second protrusion facing the end of the electrode group.

[0011] Preferably, the length of the pole group is A, and along the first direction, the sum of the length of the first protrusion and the length of the second protrusion is D, satisfying 0.18≤D / A≤0.5.

[0012] Preferably, there is one second protrusion and two electrodes, with the two electrodes located on both sides of the second protrusion in the second direction; or, there are two second protrusions and one electrode, with the two second protrusions located on both sides of the electrode in the second direction.

[0013] Preferably, between two adjacent pole groups, there is one first connecting part and two second connecting parts, and a connecting groove is formed between the two second connecting parts so that the first connecting part is engaged in the connecting groove.

[0014] Preferably, the slope of the sidewall of the connecting groove is N, and satisfies 35°≤N≤60°; and / or, the depth of the connecting groove is H, and satisfies 5mm≤H≤10mm.

[0015] Preferably, a conductive layer is provided between adjacent electrode groups, and the conductive layer is provided in a one-to-one correspondence with the second connection portion, so that the adjacent electrode groups are electrically connected.

[0016] Preferably, the area of ​​the conductive layer is equal to the end area of ​​the second connection portion, the area of ​​the conductive layer is S1, the cross-sectional area of ​​the electrode group perpendicular to the first direction is S, and satisfies 0.45≤2S1 / S≤0.8.

[0017] The beneficial effects of this invention are:

[0018] A battery includes at least two electrode groups, a cover assembly, and a housing. The electrode groups are electrically connected to each other, and each electrode group has a tab connected to its end. One end face of an adjacent electrode group facing the other is connected to a first connecting portion, and the other end face is correspondingly connected to a second connecting portion. The first connecting portion and the second connecting portion are snapped together. The cover assembly includes a cover body and a terminal post. The cover body is disposed at the end of the electrode group in a first direction, and the terminal post is disposed on the cover body and connected to the tab. The housing is connected to the cover body and encloses a space for accommodating the electrode groups. The first direction is the height direction of the cover body.

[0019] In this way, the two electrode groups are snapped together through the first connecting part and the second connecting part, which increases the battery capacity and restricts the position of the two electrode groups in the housing, making the connection between the electrode groups more stable, preventing the electrode groups from shifting during assembly and affecting the assembly effect, improving space utilization, effectively utilizing the space at the ends of the electrode groups, and making the battery structure more compact. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the battery structure in Embodiment 1 of the present invention;

[0021] Figure 2 This is a cross-sectional view of the battery in Embodiment 1 of the present invention;

[0022] Figure 3 This is a schematic diagram of the shell structure in Embodiment 1 of the present invention;

[0023] Figure 4 This is a schematic diagram of the first structure of the pole group in Embodiment 1 of the present invention;

[0024] Figure 5 This is a first front view of the pole group in Embodiment 1 of the present invention;

[0025] Figure 6 This is a side view of the pole group in Embodiment 1 of the present invention;

[0026] Figure 7 This is a schematic diagram of the second structure of the pole group in Embodiment 1 of the present invention;

[0027] Figure 8 This is a schematic diagram of the third structure of the pole group in Embodiment 1 of the present invention;

[0028] Figure 9 This is a second front view of the pole group in Embodiment 1 of the present invention;

[0029] Figure 10 This is a first structural schematic diagram of the cover plate assembly in Embodiment 1 of the present invention;

[0030] Figure 11 This is a schematic diagram of the second structure of the cover plate assembly in Embodiment 1 of the present invention;

[0031] Figure 12 This is a cross-sectional view of the cover plate assembly in Embodiment 1 of the present invention;

[0032] Figure 13 This is a first front view of the pole group in Embodiment 2 of the present invention;

[0033] Figure 14 This is the second front view of the pole group in Embodiment 2 of the present invention.

[0034] In the picture:

[0035] 1. Electrode assembly; 11. Electrode tab; 12. First connecting part; 13. Second connecting part; 14. First protrusion; 15. Second protrusion; 16. Connecting groove; 17. Conductive layer; 2. Cover plate assembly; 21. Cover plate body; 22. Electrode post; 23. Riveting block; 24. First plastic; 241. Vent hole; 25. Second plastic; 26. Third plastic; 3. Housing; Z, First direction; X, Second direction; Y, Third direction. Detailed Implementation

[0036] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0037] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0039] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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 present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0040] See Figures 1 to 3 The present invention provides a battery comprising at least two electrode groups 1, a cover plate assembly 2, and a housing 3. The electrode groups 1 are electrically connected to each other, and each electrode group 1 has a tab connected to its end. One of the adjacent electrode groups 1 has a first connecting portion 12 connected to its end face facing the other, and the other has a corresponding second connecting portion 13 connected to it. The first connecting portion 12 and the second connecting portion 13 are snapped together. The cover plate assembly 2 comprises a cover plate body 21 and a terminal post 22. The cover plate body 21 is disposed at the end of the electrode group 1 in a first direction Z, and the terminal post 22 is disposed on the cover plate body 21 and connected to the tab. The housing 3 is connected to the cover plate body 21 and encloses a space for accommodating the electrode groups 1. The first direction Z is the height direction of the cover plate body 21.

[0041] In this embodiment, there are two pole groups 1, which are arranged along the length of the pole group 1 and their end faces abut against each other. There are two cover plate bodies 21, which are respectively located on the end faces of the two pole groups 1 that are far apart from each other. The pole post 22 is fixedly connected to the cover plate. The housing 3 is sleeved on the pole group 1 and fixedly connected to the cover plate body 21 by welding.

[0042] In this way, the two electrode groups 1 are snapped together through the first connecting part 12 and the second connecting part 13, which can restrict the position of the two electrode groups 1 in the housing 3, making the connection between the electrode groups 1 more stable, avoiding the electrode groups 1 from moving around during the assembly process and affecting the assembly effect, and facilitating the improvement of battery capacity and space utilization. The cover plate assembly 2 is set at the end of the electrode group 1 in the first direction Z, which can effectively utilize the end space of the electrode group 1 and make the battery structure more compact.

[0043] It is understandable that the number of pole groups 1 can be adjusted according to actual needs, which will not be elaborated here.

[0044] See Figures 2 to 6In some embodiments, the electrode assembly 1 is further connected to a first protrusion 14 and a second protrusion 15. The first protrusion 14 is disposed on the side of the electrode assembly 1 in the second direction X, and the second protrusion 15 is disposed at the end of the electrode assembly 1 in the first direction Z. The cover plate assembly 2 is connected to the second protrusion 15. In the first direction Z, the second protrusion 15 protrudes from the surface of the electrode assembly 1 and is disposed on the electrode post 22 from the surface of the electrode assembly 1. The second direction X is the length direction of the cover plate body 21.

[0045] In this embodiment, one electrode group 1 is connected to two first protrusions 14, and the two first protrusions 14 are symmetrically arranged on the side of the electrode group 1 in the width direction. The second protrusion 15 is arranged on the end face of the two electrode groups 1 that are far apart from each other. The first protrusions 14 and the second protrusions 15 are integrally formed with the electrode group 1 to improve the battery capacity. The third direction Y is the width direction of the cover body 21, and the first direction Z, the second direction X and the third direction Y are perpendicular to each other.

[0046] Thus, by setting the first protrusion 14 and the second protrusion 15, the battery capacity can be increased, and the space on the side and end of the electrode assembly 1 can be effectively utilized. The first protrusion 14 is symmetrically arranged on both sides of the electrode assembly 1, which can make the electrode assembly 1 bear force evenly, reduce the risk of deformation caused by uneven force during use, and improve battery safety. The second protrusion 15 protrudes from the cover plate body 21, which can protect the terminal post 22, reduce the risk of the terminal post 22 being hit by external impacts, and make full use of the space on both sides of the cover plate body 21, so that the electrode tab can be directly connected to the terminal post 22, reduce the number of structural components, reduce costs, and make the battery structure more compact.

[0047] It is understandable that the positions of the first protrusion 14 and the second protrusion 15 can be adjusted according to actual needs, and will not be listed in detail here.

[0048] Further, see Figures 2 to 4 In some embodiments, the cover plate assembly 2 further includes a riveting block 23 connected to the pole post 22. In the first direction Z, the second protrusion 15 protrudes from the surface of the pole group 1 and is disposed on the surface of the riveting block 23 away from the surface of the pole group 1.

[0049] In this embodiment, the riveting block 23 is fixedly disposed at one end of the pole post 22 away from the pole group 1. The riveting block 23 and the pole post 22 are arranged in a one-to-one correspondence and are fixedly connected.

[0050] Thus, the protruding second protrusion 15 can improve the protection of the rivet block 23, prevent the rivet block 23 from colliding with the external structure, and the second protrusion 15 can improve the connection stability between the cover body 21 and the electrode group 1, improve the overall structural strength of the cover assembly 2, make full use of the space on both sides of the cover body 21 in the first direction Z, improve the space utilization rate, and improve the safety and stability of the battery.

[0051] It is understandable that the number and position of the rivet blocks 23 can be adjusted according to actual needs, and will not be listed in detail here.

[0052] See Figure 7 and Figure 8 In some embodiments, along the first direction Z, the area of ​​the second protrusion 15 away from the end of the electrode group 1 is smaller than the area of ​​the second protrusion 15 toward the end of the electrode group 1.

[0053] See Figure 5 In some embodiments, the second protrusion 15 is provided with one, and the electrode tabs are provided with two, with the two electrode tabs provided on both sides of the second protrusion 15 in the second direction X.

[0054] In this embodiment, the second protrusion 15 is an equilateral trapezoidal boss structure, and two electrode ears are symmetrically arranged on both sides of the second protrusion 15. The second protrusion 15 is located in the middle of the end of the electrode group 1, and the position of the cover plate body 21 corresponding to the second protrusion 15 is adapted to the shape of the second protrusion 15.

[0055] Thus, the second protrusion 15 can provide stable support for the cover body 21, improve the structural strength at the connection between the cover assembly 2 and the electrode group 1, and effectively utilize the space between the cover body 21 and the electrode group 1 so that the electrode tab and the electrode post 22 can be directly connected, reducing the number of structural components and cost, and making the overall structure of the battery more compact.

[0056] It is understood that the second protrusion 15 can also be a cuboid or other structure. In this embodiment, the second protrusion 15 is an equilateral trapezoidal boss structure, which is to reserve enough space on both sides of the second protrusion 15 to assemble the rivet block 23 and connect the adjacent battery. The shape of the second protrusion 15 can be adjusted according to actual needs, and will not be listed in detail here.

[0057] See Figure 9 In some embodiments, the first protrusion 14 and the second protrusion 15 are both disposed on the side of the pole group 1 away from the first connecting portion 12 or the second connecting portion 13.

[0058] In this way, the size of one end of the electrode assembly 1 can be avoided from being too large, which would affect the stability of the electrode assembly 1 inside the housing 3. The space at both ends of the combined electrode assembly 1 in the first direction can be effectively utilized, thereby improving the battery space utilization rate, increasing the battery capacity, and improving the battery performance.

[0059] See Figure 9 In some embodiments, the length of pole group 1 is A, along the first direction Z, the sum of the length of the first protrusion 14 and the length of the second protrusion 15 is D, and satisfies 0.18≤D / A≤0.5.

[0060] In this embodiment, the ratio of the sum D of the length of the first protrusion 14 and the length of the second protrusion 15 to the length A of the pole group 1 can be any value between 0.18 and 0.5 or any range between two values, such as 0.18, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, etc.

[0061] In this way, the size of the electrode assembly 1 can be more coordinated while increasing the battery capacity, avoiding excessive local weight or uneven stress, improving the stability of the electrode assembly 1 inside the battery, and facilitating the pushing of the electrode post 22 after the cover plate assembly 2 is assembled into the housing 3, thereby improving the stability and safety of the battery.

[0062] Understandably, the ratio of the sum of the lengths of the first protrusion 14 and the second protrusion 15 (D) to the length of the electrode group 1 (A) cannot be too small, as this would affect the battery capacity. Conversely, the ratio of the sum of the lengths of the first protrusion 14 and the second protrusion 15 (D) to the length of the electrode group 1 (A) cannot be too large, as this would result in a larger overall battery volume and require more space. The ratio of the sum of the lengths of the first protrusion 14 and the second protrusion 15 (D) to the length of the electrode group 1 (A) can be adjusted according to actual needs, and will not be listed in detail here.

[0063] See Figure 5 In some embodiments, between two adjacent pole groups 1, there is one first connecting part 12 and two second connecting parts 13, and a connecting groove 16 is formed between the two second connecting parts 13 so that the first connecting part 12 is engaged in the connecting groove 16.

[0064] In this embodiment, the shape of the first connecting part 12 is adapted to the shape of the connecting groove 16, and the first connecting part 12 abuts against the end face of the pole group 1 where the second connecting part 13 is provided. That is, the first connecting part 12 abuts against the side wall of the connecting groove 16. The second connecting part 13 is a right-angled trapezoidal boss structure, and the two second connecting parts 13 are respectively flush with the two side faces in the width direction of the pole group 1. The cross-sectional area of ​​the connecting groove 16 is an equilateral trapezoid.

[0065] In this way, the first connecting part 12 can be stably locked in the connecting groove 16, which improves the structural strength of the connection between the two adjacent electrode groups 1, reduces the risk of deformation and displacement of the electrode group 1 during assembly and use, and improves the safety and stability of the battery. Furthermore, the first connecting part 12 and the second connecting part 13 not only enable the two electrode groups 1 to be set in one housing 3 to increase the battery capacity, but the first connecting part 12 and the second connecting part 13 themselves can also increase the volume of the electrode group 1, thereby achieving the effect of increasing the battery capacity.

[0066] It is understandable that the number, shape and position of the first connecting part 12 and the second connecting part 13 can be adjusted according to actual needs, as long as the position of the adjacent pole group 1 is restricted within the housing 3, and will not be listed in detail here.

[0067] See Figure 9 In some embodiments, the slope of the sidewall of the connecting groove 16 is N, and satisfies 35°≤N≤60°, and the depth of the connecting groove 16 is H, and satisfies 5mm≤H≤10mm.

[0068] In this embodiment, the slope N of the sidewall of the connecting groove 16 can be any value between 35° and 60° or any range between any two values, such as 35°, 40°, 45°, 50°, 55°, 60°, etc., and the depth H of the connecting groove 16 can be any value between 5mm and 10mm or any range between any two values, such as 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc.

[0069] In this way, the first connecting part 12 can be stably locked in the connecting groove 16, and the first connecting part 12 and the second connecting part 13 can limit the relative position of the two adjacent electrode groups 1, prevent the electrode group 1 from shifting, improve the stability of the electrode group 1 in the housing 3, and thus improve the safety of the battery; the side wall of the connecting groove 16 is inclined, which can guide the first connecting part 12 into the connecting groove 16, reducing the assembly difficulty.

[0070] Understandably, the slope N of the sidewall of the connecting groove 16 cannot be too small. If it is too small, it will increase the risk of deformation of the contact surface during the assembly of adjacent electrode groups 1, resulting in poor contact between electrode groups 1. The slope N of the sidewall of the connecting groove 16 cannot be too large either. If it is too large, it will be difficult for the first connecting part 12 to be positioned in the connecting groove 16, causing the electrode group 1 to be skewed, have poor contact, etc., affecting the battery yield. The depth H of the connecting groove 16 cannot be too small. If it is too small, it will result in insufficient structural strength at the connection between the first connecting part 12 and the connecting groove 16, making it difficult to restrict the relative position between adjacent electrode groups 1. The depth H of the connecting groove 16 cannot be too large either. If it is too large, it will occupy too much space, increasing the risk of assembly interference of the first connecting part 12.

[0071] See Figure 8In some embodiments, a conductive layer 17 is provided between adjacent electrode groups 1, and the conductive layer 17 is provided in a one-to-one correspondence with the second connection portion 13 so that adjacent electrode groups 1 are electrically connected.

[0072] In this embodiment, adjacent electrode groups 1 are provided with tabs of opposite polarity at the positions where the second connection portion 13 is provided. The conductive layer 17 is coated on both sides of the tabs, and the conductive layer 17 on both sides of the tabs is connected to the adjacent electrode groups 1, so that the adjacent electrode groups 1 are electrically connected through the conductive layer 17.

[0073] This enables a stable electrical connection between adjacent electrode groups 1, reduces connecting components, lowers costs, saves internal space in the housing 3 to increase battery capacity, and makes the internal structure of the housing 3 more compact, thereby improving battery space utilization.

[0074] It is understandable that the tabs between adjacent electrode groups 1 can also be electrically connected by welding. The electrical connection method between adjacent electrode groups 1 can be adjusted according to actual needs, and will not be listed in detail here.

[0075] See Figure 6 In some embodiments, the area of ​​the conductive layer 17 is equal to the end area of ​​the second connection portion 13, the area of ​​the conductive layer 17 is S1, the cross-sectional area of ​​the electrode group 1 perpendicular to the first direction Z is S, and satisfies 0.45≤2S1 / S≤0.8.

[0076] In this embodiment, the ratio of twice the area S1 of the conductive layer 17 (that is, the total area of ​​the conductive layer 17) to the cross-sectional area S of the electrode group 1 perpendicular to the first direction Z can be any value between 0.45 and 0.8 or any range between two values, such as 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, etc.

[0077] In this way, by limiting the ratio of the area S1 of the conductive layer 17 to the cross-sectional area S of the electrode group 1 perpendicular to the first direction Z, the adjacent electrode groups 1 can have sufficient overcurrent capacity, and the structural stability of the connection between the adjacent electrode groups 1 can be improved, thereby improving the safety and stability of the battery.

[0078] Understandably, the ratio of twice the area S1 of the conductive layer 17 to the cross-sectional area S of the electrode group 1 perpendicular to the first direction Z cannot be too small. If it is too small, the area of ​​the conductive layer 17 will be too small, resulting in poor current carrying capacity. The ratio of twice the area S1 of the conductive layer 17 to the cross-sectional area S of the electrode group 1 perpendicular to the first direction Z cannot be too large either. If it is too large, the size of the connecting groove 16 will be too small, affecting the limiting effect of the first connecting part 12 and the connecting groove 16.

[0079] See Figures 10 to 12In some embodiments, the cover assembly 2 further includes a first plastic 24, a second plastic 25, a third plastic 26, and an explosion-proof valve (not shown in the figure). The first plastic 24 is disposed between the second protrusion 15 and the cover body 21, the second plastic 25 is disposed between the terminal post 22 and the cover body 21, and the third plastic 26 is disposed between the riveting block 23 and the cover body 21 to achieve an insulated connection between the terminal post 22, the riveting block 23, the second protrusion 15, and the cover body 21. The explosion-proof valve is disposed on the cover body 21 at the position corresponding to the first plastic 24. The first plastic 24 has multiple vent holes 241, so that when the battery experiences thermal runaway, a large amount of gas can be concentratedly discharged to the explosion-proof valve through the vent holes 241.

[0080] Example 2

[0081] In Embodiment 2, the same or corresponding components as in Embodiment 1 are referred to using the same reference numerals as in Embodiment 1. For simplicity, only the differences between Embodiment 2 and Embodiment 1 are described.

[0082] See Figure 13 and Figure 14 In some embodiments, two second protrusions 15 are provided, and one electrode tab is provided. The two second protrusions 15 are provided on both sides of the electrode tab in the second direction X.

[0083] In this embodiment, the second protrusion 15 is a right-angled trapezoidal boss structure. The sidewall of the second protrusion 15 in the second direction X is flush with the sidewall of the first protrusion 14 in the second direction X. The two second protrusions 15 are symmetrically arranged at both ends of the end face of the pole group 1 in the second direction X. The pole ear is arranged in the middle of the end face of the pole group 1. The position of the cover plate body 21 corresponding to the second protrusion 15 is adapted to the shape of the second protrusion 15 so that the cover plate body 21 abuts against the second protrusion 15 and the end of the pole group 1.

[0084] Thus, the two symmetrically arranged second protrusions 15 can increase the battery capacity, improve the structural strength of the connection between the second protrusions 15 and the cover body 21, and make the end of the electrode assembly 1 uniformly stressed, reducing the risk of deformation when the electrode assembly 1 is inserted into the casing, so that the electrode assembly 1 can be stably set inside the casing 3, and improving the safety of the battery.

[0085] It is understood that the second protrusion 15 can also be a cuboid structure. In this embodiment, the second protrusion 15 is a right-angled trapezoidal boss structure, which can provide sufficient assembly space between the two second protrusions 15 to assemble the pole post 22 and the rivet block 23, and facilitate the series and parallel connection between adjacent batteries through the rivet block 23. The shape of the second protrusion 15 can be adjusted according to actual needs, and will not be listed in detail here.

[0086] To verify the rationality of the following parameters: depth H of connecting groove 16, the sum of the lengths of the first protrusion 14 and the second protrusion 15 being D, length A of electrode group 1, slope N of the sidewall of connecting groove 16, width L1 of electrode group 1, sum of the width of electrode group 1 and the maximum width of the first protrusion 14 being L2, thickness T of electrode group 1, area S1 of conductive layer 17, and range of cross-sectional area S of electrode group 1 perpendicular to the first direction Z, as shown in Table 1, this embodiment provides six sets of embodiments and six sets of comparative examples for illustration.

[0087] Table 1

[0088]

[0089] As shown in Examples 1 to 9 in the table, after meeting the range limitations, the cell yield meets the requirements, and no imbalance in the end support of counter electrode group 1 or damage to counter electrode group 1 or the electrode tabs occurs during the process. The overcurrent capacity of the electrode tabs and the cell capacity both meet the requirements.

[0090] As shown in Comparative Example 1 in the table, when the slope N of the sidewall of the connecting groove 16 is too small, the yield of the battery cell does not meet the requirements, and the slope of the mating position of the two electrode groups 1 is too small. During the assembly of the two electrode groups 1, extrusion deformation will occur, resulting in misalignment and poor contact on both sides.

[0091] As shown in Comparative Example 2 in the table, when the slope N of the sidewall of the connecting groove 16 is too large, the yield of the battery cells does not meet the requirements, and the slope of the mating position of the two electrode groups 1 is too large. During the assembly of the two electrode groups 1, poor positioning will occur, leading to misalignment and poor contact on both sides.

[0092] As shown in Comparative Example 3 in the table, when the depth H of the connecting groove 16 is too small, the yield of the battery cell does not meet the requirements, and the dimensions of the first connecting part 12 and the connecting groove 16 are insufficient. Effective positioning cannot be achieved, resulting in misalignment and poor contact on both sides of the electrode group 1.

[0093] As shown in Comparative Example 4 in the table, when the depth H of the connecting groove 16 is too large, the yield of the battery cells does not meet the requirements, and the dimensions of the first connecting part 12 and the connecting groove 16 are too large. The first connecting part 12 is too large, which requires high assembly process, and the electrode group 1 where the first connecting part 12 is set has been damaged.

[0094] As shown in Comparative Example 5 in the table, when the ratio of twice the area S1 of the conductive layer 17 to the cross-sectional area S of the electrode group 1 perpendicular to the first direction Z is too small, the cell yield does not meet the requirements, and the area of ​​the conductive layer 17 on both sides of the electrode group 1 is insufficient. This leads to overcurrent at the contact position of adjacent electrode groups 1, which does not meet the cell requirements.

[0095] As can be seen from Comparative Example 6 in the table, when the ratio of twice the area S1 of the conductive layer 17 to the cross-sectional area S of the electrode group 1 perpendicular to the first direction Z is too large, the yield of the battery cell does not meet the requirements. The area ratio of the conductive layer 17 of the two electrode groups 1 is too large, which increases the cost. The size of the first connection part 12 is insufficient and cannot be effectively positioned.

[0096] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A battery, characterized in that, include: At least two pole groups (1) are electrically connected to each other. Each pole group (1) has a tab connected to its end. One of the adjacent pole groups (1) is connected to the end face of the other with a first connecting part (12) and the other is connected to a second connecting part (13). The first connecting part (12) and the second connecting part (13) are snapped together. Cover plate assembly (2), the cover plate assembly (2) includes a cover plate body (21) and a pole post (22), the cover plate body (21) is disposed at the end of the pole group (1) in the first direction (Z), and the pole post (22) is disposed on the cover plate body (21) and connected to the pole tab; The housing (3) is connected to the cover plate body (21) and encloses a space for accommodating the pole group (1); The first direction (Z) is the height direction of the cover plate body (21).

2. The battery according to claim 1, characterized in that, The pole assembly (1) is also connected to a first protrusion (14) and a second protrusion (15). The first protrusion (14) is disposed on the side of the pole assembly (1) in the second direction (X), and the second protrusion (15) is disposed at the end of the pole assembly (1) in the first direction (Z). The cover plate assembly (2) is connected to the second protrusion (15). In the first direction (Z), the second protrusion (15) protrudes from the surface of the pole assembly (1) and is disposed on the surface of the pole post (22) from the surface of the pole assembly (1). The second direction (X) is the length direction of the cover plate body (21).

3. The battery according to claim 2, characterized in that, The cover plate assembly (2) further includes a riveting block (23) connected to the pole post (22). In the first direction (Z), the second protrusion (15) protrudes from the surface of the pole group (1) and is disposed on the surface of the riveting block (23) away from the pole group (1).

4. The battery according to claim 2, characterized in that, Along the first direction (Z), the area of ​​the second protrusion (15) away from the end of the pole group (1) is smaller than the area of ​​the second protrusion (15) facing the end of the pole group (1).

5. The battery according to claim 2, characterized in that, The length of the pole group (1) is A. Along the first direction (Z), the sum of the length of the first protrusion (14) and the length of the second protrusion (15) is D, and satisfies 0.18≤D / A≤0.

5.

6. The battery according to claim 2, characterized in that, There is one second protrusion (15) and two electrodes. The two electrodes are located on both sides of the second protrusion (15) in the second direction (X). Alternatively, there are two second protrusions (15) and one electrode. The two second protrusions (15) are located on both sides of the electrode in the second direction (X).

7. The battery according to any one of claims 1-6, characterized in that, Between two adjacent pole groups (1), there is one first connecting part (12) and two second connecting parts (13), and a connecting groove (16) is formed between the two second connecting parts (13) so that the first connecting part (12) is engaged in the connecting groove (16).

8. The battery according to claim 7, characterized in that, The slope of the sidewall of the connecting groove (16) is N, and satisfies 35°≤N≤60°; and / or, the depth of the connecting groove (16) is H, and satisfies 5mm≤H≤10mm.

9. The battery according to claim 7, characterized in that, A conductive layer (17) is provided between adjacent electrode groups (1), and the conductive layer (17) is provided in a one-to-one correspondence with the second connection part (13) so that the adjacent electrode groups (1) are electrically connected.

10. The battery according to claim 9, characterized in that, The area of ​​the conductive layer (17) is equal to the end area of ​​the second connection part (13), the area of ​​the conductive layer (17) is S1, the cross-sectional area of ​​the pole group (1) perpendicular to the first direction (Z) is S, and satisfies 0.45≤2S1 / S≤0.8.

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