Battery cell

Abstract

The invention relates to the technical field of batteries, and provides a battery cell, which comprises: a battery cell shell provided with an opening; the battery cell cover plate comprises a cover plate body and a pole, the cover plate body is arranged at the opening, the cover plate body and the battery cell shell define a containing cavity, a first supporting table, a mounting table and a second supporting table are arranged on the outer side face of the cover plate body, the mounting table is located between the first supporting table and the second supporting table, and the pole penetrates through the cover plate body and protrudes out of the mounting table; a first sinking groove, a third sinking groove and a second sinking groove are formed in the positions, corresponding to the first supporting table, the mounting table and the second supporting table, of the inner side surface of the battery cell cover plate respectively; the pole group is arranged in the containing cavity, the pole lug is connected to the connecting end face of the pole group and connected with the pole column, a first convex hull and a second convex hull which are arranged in the length direction are arranged on the connecting end face, the first convex hull is contained in the first sinking groove, the second convex hull is contained in the third sinking groove, and the pole lug is contained in the second sinking groove. The battery cell can improve the energy density of the battery pack and increase the capacity of the battery cell.

Description

Technical Field

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

[0002] The battery pack includes a casing and battery modules assembled inside the casing. Each battery module consists of multiple cells, with the terminals of these cells electrically connected via busbars. The casing provides physical support for the battery modules, protecting them from external impacts and pressure, while also preventing the intrusion of moisture, dust, and other impurities. As users' demands for longer battery life continue to increase, current battery technology faces a contradiction: battery capacity development lags behind market demand, leading to user range anxiety.

[0003] In traditional battery pack structures, to prevent the busbars and terminals from being squeezed when the casing deforms under external impact, a large space is left between the busbars and the battery pack casing. However, this requires reducing the volume of the cells, resulting in low energy density of the battery pack and low cell capacity. Summary of the Invention

[0004] This invention provides a battery cell to solve the problems of low energy density in existing battery packs and low cell capacity.

[0005] This invention provides a battery cell, comprising: The battery cell casing has an opening; A battery cell cover plate includes a cover plate body and an electrode post. The cover plate body is disposed at the opening and surrounds the battery cell housing to form a receiving cavity. On the side of the cover plate body away from the receiving cavity, a first support platform, a mounting platform, and a second support platform are arranged sequentially along its length. The electrode post passes through the cover plate body and protrudes from the mounting platform. On the side of the battery cell cover plate facing the receiving cavity, a first groove, a third groove, and a second groove are respectively formed at the positions of the first support platform, the mounting platform, and the second support platform. An electrode assembly is disposed within the receiving cavity and has a connecting end face and an electrode tab. The electrode tab is connected to the connecting end face and connected to the electrode post. The connecting end face has a first convex bulge and a second convex bulge arranged along the length direction. The first convex bulge is received in the first recessed groove, the second convex bulge is received in the third recessed groove, and the electrode tab is received in the second recessed groove.

[0006] According to a battery cell provided by the present invention, there are two mounting platforms and two second support platforms, with the first support platform located between the two second support platforms, and the two mounting platforms respectively disposed on both sides of the first support platform, each mounting platform having a terminal post inserted through it; there are two second protrusions, with the two second protrusions respectively disposed on both sides of the first protrusion.

[0007] According to a battery cell provided by the present invention, the cover plate body has a reference surface, the first support platform, the mounting platform and the second support platform protrude from the reference surface, and the protrusion height of the first support platform and the second support platform relative to the reference surface is greater than the protrusion height of the end of the electrode post protruding from the mounting platform relative to the reference surface.

[0008] According to a battery cell provided by the present invention, the first support platform, the mounting platform and the second support platform are connected to form an integral boss, the first sink groove, the third sink groove and the second sink groove are connected to form an integral sink groove, the first convex bud and the second convex bud are connected to form a stepped convex bud, the protrusion height of the first convex bud is greater than the protrusion height of the second convex bud, and the first convex bud is limited and matched with the first sink groove.

[0009] According to a battery cell provided by the present invention, the battery cell cover further includes an insulating member, the insulating member being disposed on the side of the cover body near the electrode assembly, the electrode post passing through the insulating member, a groove being formed on the side of the cover body facing the receiving cavity corresponding to the position of the integral boss, the insulating member engaging with the groove, and an integral recess being formed on the side of the insulating member away from the cover body corresponding to the position of the groove.

[0010] According to a battery cell provided by the present invention, the electrode assembly includes two electrode assembly units, each electrode assembly unit having a first end face and a tab, the tab being connected to the first end face, the first end face having a protrusion, each electrode assembly unit having an inner side and an outer side facing away from each other in the width direction of the cover plate body, the protrusion being flush with the inner side, the protrusion having a gap between it and the outer side in the width direction, the inner sides of the two electrode assembly units being in contact with each other, and the two protrusions facing away from each other in the width direction being combined to form the stepped protrusion.

[0011] According to a battery cell provided by the present invention, the distance between the protrusion and the outer side surface in the width direction is b, where 7mm≤b≤15mm.

[0012] According to a battery cell provided by the present invention, the cover plate body has a reference surface, the integral boss protrudes from the reference surface, the side wall of the integral boss and the reference surface form an angle of 90°+β, the side of the first protrusion and the connecting end face form an angle of 90°+θ, 15°≤β≤25°, 15°≤θ≤25°, -3≤θ-β≤3°; And / or, the assembly gap between the top surface of the stepped convex bulge and the integral recessed groove is c, 0.3mm≤c≤0.8mm, and the assembly gap between the side surface of the first convex bulge and the first recessed groove is d, 1.5mm≤d≤2.5mm. And / or, the distance between the two ends of the stepped convex bulge in the length direction and the edge of the pole group is G1, 35mm≤G1≤50mm.

[0013] According to a battery cell provided by the present invention, the tab has a root section and a closing section. The root section is connected to the connecting end face, and the closing section is connected to the end of the root section away from the connecting end face. The position where the root section and the closing section are connected is the closing position of the tab. The distance between the outer side of the electrode assembly on one side of the cover plate body in the width direction and the closing position is a, where 1mm≤a≤3mm.

[0014] According to a battery cell provided by the present invention, in the thickness direction of the cover plate body, the height of the first convex bulge relative to the connecting end face is H1, and the height of the second convex bulge relative to the connecting end face is H2, where 3.5mm≤H1-H2≤5mm.

[0015] The battery cell provided by this invention utilizes a first and second support platform on the cover plate body. These platforms are connected to the battery pack housing for support, allowing the cell's outer shell to also function as a load-bearing component. This prevents significant deformation of the housing, reduces its thickness, and lightens the battery pack weight. Furthermore, while ensuring the housing does not cause compression damage to the busbars and terminals, the distance between the busbars and the housing is reduced, thereby increasing the cell's volume, fully utilizing the internal space of the housing, improving the battery pack's energy density, and increasing the cell's capacity. Heat from the cell can be transferred to the housing via the first and second support platforms, improving the cell's heat dissipation efficiency. The mounting platform on the cover plate body increases the structural strength of the area corresponding to the terminals, reducing the risk of short circuits caused by deformation of the cover plate body under impact that could compress the terminals.

[0016] The cell cover plate facing the electrode assembly has a first recess, a second recess, and a third recess corresponding to the positions of the first support platform, the second support platform, and the mounting platform, respectively. This helps to expand the internal space of the cell. At the same time, by setting a first convex bud and a second convex bud on the electrode assembly, with the first convex bud housed in the first recess and the second convex bud housed in the third recess, and the electrode tab housed in the second recess, the utilization rate of the internal space of the cell is increased and the capacity of the cell is further increased. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the battery cell provided by the present invention.

[0019] Figure 2 This is an assembly diagram of the cell electrode assembly and cell cover plate provided by the present invention.

[0020] Figure 3 This is a cross-sectional view of the assembly structure of the electrode group and the cell cover plate of the battery cell provided by the present invention.

[0021] Figure 4 yes Figure 3 A magnified view of part A shown in the middle circle.

[0022] Figure 5 This is one of the structural schematic diagrams of the battery cell cover plate provided by the present invention.

[0023] Figure 6 This is one of the structural schematic diagrams of the cover plate body in the battery cell cover plate provided by the present invention.

[0024] Figure 7 This is the second schematic diagram of the structure of the cover plate body in the battery cell cover plate provided by the present invention.

[0025] Figure 8 This is the second schematic diagram of the structure of the battery cell cover plate provided by the present invention.

[0026] Figure 9 This is a partial structural cross-sectional view of the battery cell cover plate provided by the present invention.

[0027] Figure 10 This is one of the structural schematic diagrams of the electrode group unit in the battery cell provided by the present invention.

[0028] Figure 11 This is the second schematic diagram of the structure of the electrode group unit in the battery cell provided by the present invention.

[0029] Figure 12 This is a partial structural schematic diagram of the electrode group unit in the battery cell provided by the present invention.

[0030] Figure 13 This is a schematic diagram of the assembly process of the cell electrode assembly and cell cover plate provided by the present invention.

[0031] Figure label: 1. Cover plate body; 101. First groove; 102. Second groove; 103. Third groove; 10. Base plate; 11. First support platform; 12. Second support platform; 13. Mounting platform; 131. Positioning groove; 132. Through hole; 2. Electrode post; 21. Connecting post; 22. Riveting block; 3. Insulating component; 301. First recessed groove; 302. Second recessed groove; 303. Third recessed groove; 4. Connecting piece; 41. Welding part; 42. Base part; 43. Connecting part; 5. Top plastic; 6. Cell housing; 7. Electrode group; 70. Electrode group unit; 701. First protrusion; 702. Second protrusion; 703. First end face; 704. Inner side; 705. Outer side; 71. First convex bud; 72. Second convex bud; 73. Connecting end face; 74. Electrode lug; 741. Root section; 742. Closing section. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0033] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "first" and "second" are numbered for the purpose of clearly identifying product components and do not represent any substantial difference. The terms "installed," "connected," and "linked" 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 direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances. Furthermore, "multiple" means two or more. In the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0034] The following is combined Figures 1-13 The battery cell of the present invention is described.

[0035] like Figures 1-5As shown, the battery cell provided in this embodiment of the invention includes a battery cell housing 6, a battery cell cover plate, and an electrode assembly 7. The battery cell housing 6 has an opening. The battery cell cover plate includes a cover plate body 1 and an electrode post 2. The cover plate body 1 is disposed at the opening and surrounds the battery cell housing 6 to form a receiving cavity. A first support platform 11, a mounting platform 13, and a second support platform 12 protrude from the side of the cover plate body 1 away from the receiving cavity, with the mounting platform 13 located between the first support platform 11 and the second support platform 12. The electrode post 2 passes through the cover plate body 1 and protrudes from the mounting platform 13. Figure 8 On the side of the cell cover facing the receiving cavity, corresponding to the positions of the first support platform 11, the mounting platform 13, and the second support platform 12, a first recess 301, a third recess 303, and a second recess 302 are respectively formed. Combined with... Figure 10 The electrode assembly 7 is disposed within the receiving cavity and has a connecting end face 73 and an electrode tab 74. The electrode tab 74 is connected to the connecting end face 73 and is connected to the electrode post 2. Figure 4 and Figure 8 The connecting end face 73 is provided with a first protrusion 71 and a second protrusion 72 arranged along the length direction. The first protrusion 71 is received in the first sink 301, the second protrusion 72 is received in the third sink 303, and the electrode tab 74 is received in the second sink 302.

[0036] The cell housing 6 is a cavity structure with an opening on one side. The cover plate body 1 is welded to the cell housing 6 to form the outer shell of the cell, protecting the internal components of the cell and withstanding a certain amount of external impact. The terminal post 2 protrudes from the outer surface of the cover plate body 1 to form a terminal post 2, which is used to connect to the busbar so that multiple cells can be connected through the busbar to form a battery module. The other end of the terminal post 2 is located in the receiving cavity and is connected to the tab 74 of the electrode group 7. The battery module is assembled into the housing to form a battery pack.

[0037] For the length and width directions of the cover plate body 1, see [reference]. Figure 1 The thickness direction of the cover plate body 1 is perpendicular to both its length and width directions. Specifically, the cover plate body 1 has a first side and a second side that are opposite to each other in its thickness direction. The first side faces the outside of the battery cell and is provided with a first support platform 11, a second support platform 12, and a mounting platform 13. See also Figure 6 The mounting platform 13 is provided with a through hole 132 that penetrates the cover plate body 1. The pole post 2 passes through the through hole 132 and protrudes from the mounting platform 13. One end of the pole post protruding from the mounting platform 13 forms a pole post terminal 2, and the second side faces the pole group 7 inside the receiving cavity.

[0038] The first support platform 11 and the second support platform 12 are adapted to be connected to the battery pack housing for support. In the battery pack's operating state, the first support platform 11 and the second support platform 12 can be located on the top or side of the battery cells and abut against the housing to withstand impact forces transmitted from the housing. The portion of the housing that is supported and connected to the first support platform 11 and the second support platform 12 can be the housing shell; alternatively, the housing includes a shell and a cold plate, with the cold plate located between the shell and the battery cells, and the first support platform 11 and the second support platform 12 supported and connected to the cold plate. The top surfaces of the first support platform 11 and the second support platform 12 can be coated with structural adhesive to bond them to the housing, ensuring good contact and thermal conductivity between the first support platform 11 and the second support platform 12 and the housing.

[0039] The cover plate body 1 has a reference surface, and a first support platform 11, a second support platform 12, and a mounting platform 13 protrude from the reference surface. Optionally, the protrusion height of the first support platform 11 and the second support platform relative to the reference surface is greater than the protrusion height of the end of the pole post 2 protruding from the mounting platform 13 relative to the reference surface, so as to reserve a certain space between the pole post 2 and the housing for the installation of the busbar. It is understood that the height of the first support platform 11 and the second support platform 12 relative to the reference surface is greater than the height of the mounting platform 13 relative to the reference surface.

[0040] The first support platform 11, the second support platform 12, and the mounting platform 13 are arranged along the length of the cover plate body 1. Correspondingly, the first protrusion 71, the second protrusion 72, and the electrode ear 74 on the electrode assembly 7 are arranged along the length of the cover plate body 1. In the thickness direction of the cover plate body 1, the first support platform 11 is opposite to the first protrusion 71, the second support platform 12 is opposite to the electrode ear 74, and the mounting platform 13 is opposite to the second protrusion 72.

[0041] The electrode assembly 7 is formed by stacking multiple electrode plates along the width of the cover plate body 1. Each electrode plate has a first protrusion and a second protrusion at one end corresponding to the tab 74. The first protrusions of the multiple electrode plates are stacked to form a first convex 71, and the second protrusions of the multiple electrode plates are stacked to form a second convex 72. The first convex 71 is housed in a first recess 301, and the second convex 72 is housed in a third recess 303, increasing the volume of the electrode assembly 7. The tab 74 is housed in a second recess 302, increasing the space utilization within the cell housing 6, allowing for a larger space inside the cell to accommodate the electrode assembly body, and further increasing the cell capacity.

[0042] In traditional battery pack structures, the battery pack relies solely on the casing to withstand external impacts. However, the casing plate opposite the terminal 2 has a large area, making it prone to deformation if its rigidity is insufficient. To prevent casing deformation from causing compression damage to the busbar and terminal 2, a large space needs to be reserved between the busbar and the casing in the structural design, with supporting foam installed between them. Some designs also incorporate concave and convex structures on the casing plate to enhance rigidity and prevent deformation. However, these measures result in a large gap between the cells and the casing, wasting space. Increasing the casing thickness to increase rigidity would increase the weight of the battery pack, hindering lightweight design. Furthermore, the heat from the cell cover is dissipated only through conduction between the terminal 2 and the busbar, and through its own thermal radiation, resulting in low heat dissipation efficiency and easy heat accumulation.

[0043] The battery cell provided in this embodiment of the invention, by setting a first support platform 11 and a second support platform 12 on the cover body 1 of the battery cell cover, and using the first support platform 11 and the second support platform 12 to support and connect with the battery pack housing, makes the outer shell of the battery cell itself also a supporting load-bearing component. This avoids large deformation of the housing, helps to reduce the thickness of the housing, reduces the weight of the battery pack, and also reduces the distance between the busbar and the housing while ensuring that the housing does not cause crush damage to the busbar and the terminal post 2, thereby increasing the volume of the battery cell, making full use of the internal space of the housing, improving the energy density of the battery pack, and increasing the capacity of the battery cell. The heat of the battery cell can be transferred to the housing through the first support platform 11 and the second support platform 12, improving the heat dissipation efficiency of the battery cell. By setting a mounting platform 13 on the cover body 1, the structural strength of the area of ​​the cover body 1 corresponding to the terminal post 2 is increased, reducing the risk of short circuit caused by the deformation of the cover body 1 under impact force and the crushing of the terminal post 2. The cell cover plate facing the electrode group 7 has a first recessed groove 301, a second recessed groove 302, and a third recessed groove 303 respectively corresponding to the positions of the first support platform 11, the second support platform 12, and the mounting platform 13. This helps to expand the internal space of the cell. At the same time, by setting a first protrusion 71 and a second protrusion 72 on the electrode group 7, with the first protrusion 71 being housed in the first recessed groove 301, the second protrusion 72 being housed in the third recessed groove 303, and the electrode tab 74 being housed in the second recessed groove 302, the utilization rate of the internal space of the cell is increased and the capacity of the cell is further increased.

[0044] It should be noted that the battery cell has two terminals 2, namely a positive terminal and a negative terminal. In this embodiment of the invention, the number of terminals 2 on the battery cell cover can be one or two. The number of mounting platforms 13 can be determined based on the number of terminals 2, with each terminal 2 corresponding to one mounting platform 13.

[0045] The first support platform 11, the mounting platform 13, and the second support platform 12 can be arranged at intervals in the length direction of the cover plate body 1, or can be connected in sequence along the length direction of the cover plate body 1 to form an integral convex platform. The first support platform 11, the second support platform 12, and the mounting platform 13 can be integrally formed on the cover plate body 1, or can be respectively used as independent structural members and welded and fixed to a substrate 10 to form the cover plate body 1, or the integral convex platform formed by connecting the three is used as an independent structural member and welded and fixed to a substrate 10 to form the cover plate body 1.

[0046] Optionally, the first support platform 11, the second support platform 12, and the mounting platform 13 are formed by stamping a plate. For example, the first support platform 11, the second support platform 12, and the mounting platform 13 are respectively formed by individual plates or by stamping the same plate and then welded and fixed to the substrate 10; or, the first support platform 11, the second support platform 12, and the mounting platform 13 are integrally stamped from the cover plate body 1, which simplifies the manufacturing process of the cover plate body 1.

[0047] As Figure 5 shown, in some embodiments, the number of the mounting platforms 13 and the second support platforms 12 is two, the first support platform 11 is located between the two second support platforms 12, the two mounting platforms 13 are respectively arranged on both sides of the first support platform 11, and a pole post 2 penetrates through each mounting platform 13. The number of the second convex hulls 72 is two, and the two second convex hulls 72 are respectively arranged on both sides of the first convex hull 71, forming a "convex"-shaped stepped convex hull.

[0048] It can be understood that the two sides of the cell cover plate corresponding to each pole post 2 are respectively supported and connected to the box body of the battery pack through the first support platform 11 and the second support platform 12, which plays a safer support and protection for the pole post 2 and reduces the risk of the pole post 2 being pressed. Optionally, the heights of the first support platform 11 and the second support platform 12 relative to the reference plane are the same, so that the first support platform 11 and the second support platform 12 are supported and connected to the box body on the same plane.

[0049] As Figure 6 shown, the cover plate body 1 includes a substrate 10, a first support platform 11, a second support platform 12, and a mounting platform 13. The first support platform 11, the second support platform 12, and the mounting platform 13 are connected to the substrate 10 and protrude from the substrate 10 along the thickness direction of the cover plate body 1. The reference plane of the cover plate body 1 is formed on the substrate 10.

[0050] As Figure 5 , Figure 6 and Figure 9 shown, the cell cover plate provided by the embodiment of the present invention further includes an upper plastic 5. A positioning groove 131 is provided at the top of the mounting platform 13, the upper plastic 5 is arranged in the positioning groove 131, and the pole post 2 penetrates through the upper plastic 5.

[0051] Specifically, the through hole 132 on the mounting platform 13 for inserting the pole post 2 is located within the positioning groove 131. The pole post 2 includes a connecting post 21 and a rivet block 22. The connecting post 21 passes through the cover plate body 1 and the upper plastic 5. The rivet block 22 is located on the side of the upper plastic 5 away from the cover plate body 1. The connecting post 21 and the rivet block 22 are riveted together to fix the pole post 2, the upper plastic 5, and the cover plate body 1. The upper plastic 5 is positioned within the positioning groove 131, serving as an insulating barrier between the rivet block 22 and the cover plate body 1. An insulating sealing ring is provided between the connecting post 21 and the cover plate body 1, serving as an insulating seal between them. The connecting piece 4 and the connecting post 21 can be an integral structure or a separate structure.

[0052] The first support platform 11, the second support platform 12, and the mounting platform 13 each have a top wall and side walls connected to the top wall. For example... Figure 9 As shown, in some embodiments, the angle between the sidewalls of the first support platform 11, the second support platform 12, and the mounting platform 13 and the substrate 10 is 90°+β, where 15°≤β≤25°. This helps ensure the manufacturability, structural strength, and uniform stress distribution of the first support platform 11, the second support platform 12, and the mounting platform 13, thereby improving production yield. Given the limited size of the cover plate body 1, this also increases the accommodating space of the first recess 301, the second recess 302, and the third recess 303. If the angle is too small, it is not conducive to the stamping process and easily causes significant stress concentration; if the angle is too large, the impact resistance is insufficient, and the first support platform 11, the second support platform 12, and the mounting platform 13 occupy a large area, which is not conducive to structural layout.

[0053] like Figure 5 and Figure 8 and Figure 10 As shown, in some embodiments, the first support platform 11, the mounting platform 13, and the second support platform 12 are connected to form an integral boss. The first sinker 301, the third sinker 303, and the second sinker 302 are connected to form an integral sinker. The first convex 71 and the second convex 72 are connected to form a stepped convex 72, the protrusion height of the first convex 71 is greater than the protrusion height of the second convex 72, and the first convex 71 is in a limiting fit with the first sinker 301.

[0054] Understandably, the first support platform 11 and the mounting platform 13 are connected to form a stepped boss, and correspondingly, the first recess 301 and the third recess 303 are connected to form a stepped recess, in which the stepped protrusion on the electrode assembly 7 is accommodated. The side electrode lug 74 is accommodated in the second recess 302. This fully utilizes the space along the length of the cover plate body 1, which is beneficial for increasing the dimensions of the first protrusion 71 and the second protrusion 72 along the length of the cover plate body 1, thereby increasing the volume of the electrode assembly 7.

[0055] During the cell assembly process, when assembling the assembled cell cover plate with the electrode group 7, the first recess 301 and the first protrusion 71 provide a limiting fit, which serves to position the two components during assembly. When the cell is subjected to external impact, the first recess 301 can also prevent the electrode group 7 from shifting within the casing and damaging the electrode tabs 74.

[0056] like Figure 5 As shown, the battery cell cover provided in this embodiment of the invention also includes an insulating member 3. The insulating member 3 is disposed on the side of the cover body 1 near the electrode group 7, and the electrode post 2 passes through the insulating member 3. When the battery cell cover is installed on the battery cell housing 6, the insulating member 3 is located between the cover body 1 and the electrode group 7, and is used for insulation isolation between the cover body 1 and the electrode group 7. The electrode post 2 passes through both the cover body 1 and the insulating member 3, and one end of the electrode post 2 is located on the side of the insulating member 3 away from the cover body 1, for connection with the electrode tab 74 of the electrode group 7.

[0057] Among them, such as Figures 7-9 As shown, a groove is formed on the side of the cover plate body 1 near the pole group 7, corresponding to the position of the integrated boss. The insulating member 3 is in concave-convex fit with the groove, and the side of the insulating member 3 away from the cover plate body 1 forms the integrated recessed groove corresponding to the position of the groove.

[0058] Specifically, a first groove 101 is formed on the side of the cover plate body 1 near the pole group 7, corresponding to the position of the first support platform 11; a second groove 102 is formed corresponding to the position of the second support platform 12; and a third groove 103 is formed corresponding to the position of the mounting platform 13. The first groove 101, the second groove 102, and the third groove 103 are connected to form an integral groove. A protrusion is formed on the side of the insulating member 3 near the cover plate body 1. The protrusion is located within the integral groove, and the side of the insulating member 3 away from the cover plate body 1 forms the integral recessed groove corresponding to the position of the protrusion. The first recessed groove 301 of the integral recessed groove corresponds to the first groove 101, the second recessed groove 302 corresponds to the second groove 102, and the third recessed groove 303 corresponds to the third groove 103.

[0059] Furthermore, the protrusions and integrated grooves are designed to match the shape of the grooves in the cover plate body 1 and the protrusions in the insulating member 3, thus making greater use of the internal space of the protrusions.

[0060] like Figure 9 As shown, some embodiments of the present invention provide a cell cover plate that further includes a connecting piece 4. The connecting piece 4 is located within an integrated recess. The connecting piece 4 includes a base portion 42, a connecting portion 43, and a welding portion 41 connected in sequence. The base portion 42 is located within a third recess 303 and connected to the electrode post 2, while the welding portion 41 is located within a second recess 302 opposite to and connected to the electrode tab 74. The fact that the connecting piece 4 is located within an integrated recess further improves the space utilization rate inside the cell housing 6, which is beneficial for increasing the cell capacity.

[0061] See Figure 9 and Figure 11 An integral boss protrudes from the reference surface of the cover plate body 1. The angle between the side wall of the integral boss and the reference surface is 90°+β. The angle between the side of the first protrusion 71 and the connecting end face 73 is 90°+θ, 15°≤β≤25°, 15°≤θ≤25°, and -3≤θ-β≤3°.

[0062] The integrated boss has a top wall and multiple side walls connected to the top wall, each side wall having an angle of 90°+β with the reference plane. Multiple sides of the first boss 71 correspond one-to-one with the multiple side walls of the integrated boss, each side having an angle of 90°+θ with the connecting end face 73. Considering manufacturing errors, setting 15°≤θ≤25° and -3≤θ-β≤3° helps ensure interference-free assembly between the first boss 71 and the cell cover plate.

[0063] See Figure 3 and Figure 4 The assembly gap between the top surface of the stepped convex bulge and the integrated sinker is c, 0.3mm≤c≤0.8mm. The assembly gap between the side surface of the first convex bulge 71 and the first sinker 301 is d, 1.5mm≤d≤2.5mm.

[0064] Specifically, the top surface of the stepped convex bulge includes a first top surface corresponding to the first convex bulge 71 and a second top surface corresponding to the second convex bulge 72. The assembly gap between the first top surface and the bottom of the first sink 301, and the assembly gap between the second top surface and the bottom of the third sink 303, are both c. The first convex bulge 71 and the first sink 301 are in a limiting fit, and the side of the first convex bulge 71 is in a fit with the wall of the first sink 301, with a fit gap of d. If c and / or d are too small, it will cause assembly interference between the stepped convex bulge and the integrated sink; if c and / or d are too large, it will cause space waste, which is not conducive to the increase of cell capacity, and if d is too large, it will also affect the limiting effect of the electrode group 7.

[0065] See Figure 11 The distance between the two ends of the stepped protrusion on the cover plate body 1 and the edge of the electrode group 7 along the length direction is G1, where 35mm≤G1≤50mm. The area between the two ends of the stepped protrusion on the cover plate body 1 and the edge of the electrode group 7 is used to install the tabs 74. If the value of G1 is too small, the width of the tabs 74 is limited; if the value of G1 is too large, it affects the dimension of the stepped protrusion on the length direction of the cover plate body 1, which is detrimental to increasing the cell capacity.

[0066] Optionally, the distances between the two ends of the stepped convex hull in the length direction of the cover plate body 1 and the edges of the pole group 7 are equal, that is, the stepped convex platform is centrally arranged on the cover plate body 1 in the length direction of the cover plate body 1. The dimension of the pole group 7 in the length direction of the cover plate body 1 is L1, and the dimension of the stepped convex hull in the length direction of the cover plate body 1 is L2, then G1 = (L1 - L2) / 2.

[0067] As Figure 4 and Figure 10 shown, in some embodiments, the pole group 7 includes two pole group units 70. The pole group unit 70 has a first end face 703 and pole tabs 74. The pole tabs 74 are connected to the first end face 703, and a convex portion protrudes from the first end face 703. As Figure 10 shown, each pole group unit 70 has inner side faces 704 and outer side faces 705 that face away from each other in the width direction of the cover plate body 1. The convex portion is flush with the inner side face 704, and there is a gap between the convex portion and the outer side face 705 in the width direction. The inner side faces 704 of the two pole group units 70 are in contact with each other, and the two convex portions facing each other in the width direction are in contact to form a stepped convex hull.

[0068] It can be understood that both of the two pole group units 70 are formed by stacking a plurality of electrode plates in the width direction of the cover plate body 1. Each electrode plate has a protruding portion at one end corresponding to the pole tab 74, and the protruding portions of the plurality of electrode plates are stacked to form the convex portion. The pole group unit 70 has a first end face 703 and a second end face that are opposite to each other in the thickness direction of the cover plate body 1. The pole tab 74 is connected to the first end face 703, and the convex portion protrudes from the first end face 703.

[0069] Among them, the convex portion on the pole group unit 70 is a stepped convex portion, including a connected first convex portion 701 and a second convex portion 702. The protruding height of the first convex portion 701 is greater than the protruding height of the second convex portion 702. When the number of the mounting table 13 and the second support table 12 is two, the two second convex portions 702 are respectively arranged on both sides of the first convex portion 701, forming a "convex" - shaped stepped convex portion. When the inner side faces 704 of the two pole group units 70 are in contact, the first convex portions 701 of the two pole group units 70 are in contact correspondingly to form a first convex hull 71 of the pole, and the second convex portions 702 of the two pole group units 70 are in contact correspondingly to form a second convex hull 72.

[0070] The integral convex platform has a gap from the edge of the cover plate body 1 in the width direction of the cover plate body 1. After the two pole group units 70 are in contact, their first end faces 703 are combined to form the connection end face 73 of the pole group 7. In the width direction of the cover plate body 1, the convex portions of the two pole group units 70 that face each other are in contact correspondingly to form the stepped convex hull of the pole group 7. The convex hull formed in this way has a gap from the edge of the pole group 7 in the width direction of the cover plate body 1 so as to match the convex platform.

[0071] Since the protrusion height of the first support platform 11 is greater than the protrusion height of the mounting platform 13, the protrusion height of the first protrusion 71 can be set to be greater than the protrusion height of the second protrusion 72, so as to make full use of the internal space of the first support platform 11. For example... Figure 11 As shown, in the thickness direction of the cover plate body 1, the height of the first protrusion 71 relative to the connecting end face 73 is H1, and the height of the second protrusion 72 relative to the connecting end face 73 is H2. Optionally, 3.5mm ≤ H1 - H2 ≤ 5mm.

[0072] The portion of the first protrusion 71 that extends above the second protrusion 72 extends into the first recess 301 and engages with it. If the protrusion heights of the first support platform 11 and the mounting platform 13 meet the requirements, but the H1-H2 value is too small, the engagement height between the first protrusion 71 and the first recess 301 will be insufficient, resulting in poor positioning of the electrode assembly 7. If the H1-H2 value is too large, the first protrusion 71 may easily interfere with the cell cover, causing compression of the electrode assembly 7. Simultaneously, the height difference between the first support platform 11 and the mounting platform 13 determines the upper limit of the height difference between the first protrusion 71 and the second protrusion 72. If the H1-H2 value is too large, such as a large H1 affecting the stamping yield of the first support platform 11, or a small H2 affecting the structural reinforcement effect of the mounting platform 13 on the electrode post 2 position.

[0073] like Figure 12 As shown in the figure, as a specific example, the distance between the protrusion and the outer side 705 in the width direction of the cover plate body 1 is b, where 7mm ≤ b ≤ 15mm. The distance between the protrusion and the outer side 705 is related to the distance between the integral boss and the edge of the cover plate body 1. If the value of b is too small, the distance between the integral boss and the edge of the cover plate body 1 will be too small, affecting the stamping yield, or the integral protrusion may easily interfere with the integral recess. If the value of b is too large, it will reduce the load-bearing area of ​​the first support platform 11 and the second support platform 12, affecting the structural strength of the integral boss, or causing a waste of recess space and affecting the positioning effect of the pole assembly 7.

[0074] like Figure 12 As shown, in this embodiment of the invention, the electrode tab 74 has a root section 741 and a closing section 742. The root section 741 is connected to the connecting end face 73, and the closing section 742 is connected to the end of the root section 741 away from the connecting end face 73. The position where the root section 741 and the closing section 742 are connected is the closing position of the electrode tab 74. The distance between the outer surface 705 of the electrode assembly 7 on one side of the cover plate body 1 in the width direction and the closing position is a, where 1mm ≤ a ≤ 3mm.

[0075] In this assembly, the conductive portions extending from each electrode sheet of the electrode group 7 are stacked to form tabs 74. The outer edge of the electrode group 7 corresponds to the outer surface 705 of the electrode group unit 70. After the cell cover and the electrode group 7 are assembled, the tabs 74 bend and close between the cell cover and the electrode group body from the closed position. If the value of a is too small, the tabs 74 may extend beyond the edge of the electrode group 7 after bending and closing, and may be easily scratched by the cell housing 6 when the electrode group 7 is inserted into the housing. If the value of a is too large, the closed section 742 may easily spread out, making it difficult for the tabs 74 to bend and close.

[0076] In some embodiments, the electrode tabs 74 of the two electrode units 70 are arranged opposite to each other in the width direction of the cover plate body 1, and the two opposite electrode tabs 74 can be connected to the welding portion 41 of the same connecting piece 4. See [reference needed] Figure 2 and Figure 13 This allows the tabs 74 of the two electrode units 70 to be welded to different areas of the same welding part 41, reducing the thickness of the tabs 74 of a single electrode unit 70, which can reduce the heat of welding in a single area and improve the welding yield of the electrode group 7 and the pole 2.

[0077] Optionally, the cell cover has two pole posts 2 spaced apart along the length of the cover body 1, and each pole group unit 70 has two tabs 74 spaced apart along the length of the cover body 1. The two tabs 74 of each pole group unit 70 are arranged in a one-to-one correspondence with the two pole posts 2, and the two tabs 74 corresponding to the same pole post 2 are respectively welded to different areas of the corresponding connecting piece 4.

[0078] Taking a cell cover plate with a first support platform 11 and two second support platforms 12, and the first support platform 11, the second support platforms 12, and the mounting platform 13 connected to form an integrated boss as an example, DOE experimental design is performed for some parameter value ranges defined in the embodiments of the present invention. During cell assembly, structural interference is detected. After the cells are assembled, simulation analysis is performed according to national standards, and a Z-axis (thickness direction of the cover plate body) stamping test is conducted on the battery pack to detect the deformation of the cover plate body. The experimental results are shown in Table 1, where L1, L2, H1, H2, and G1 are in mm.

[0079] Table 1: Experimental Data 1

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A battery cell, characterized in that, include: The battery cell casing has an opening; A battery cell cover plate includes a cover plate body and a terminal post. The cover plate body is disposed in the opening and surrounds the battery cell housing to form a receiving cavity. A first support platform, a mounting platform, and a second support platform are protruding from the side of the cover plate body away from the receiving cavity and arranged along its length direction. The mounting platform is located between the first support platform and the second support platform. The terminal post passes through the cover plate body and protrudes from the mounting platform. A first groove, a third groove, and a second groove are formed on the side of the battery cell cover plate facing the receiving cavity, corresponding to the positions of the first support platform, the mounting platform, and the second support platform, respectively. An electrode assembly is disposed within the receiving cavity and has a connecting end face and an electrode tab. The electrode tab is connected to the connecting end face and connected to the electrode post. The connecting end face has a first convex bulge and a second convex bulge arranged along the length direction. The first convex bulge is received in the first recessed groove, the second convex bulge is received in the third recessed groove, and the electrode tab is received in the second recessed groove.

2. The battery cell according to claim 1, characterized in that, The number of mounting platforms and second support platforms is two, the first support platform is located between the two second support platforms, the two mounting platforms are respectively located on both sides of the first support platform, and each mounting platform is provided with the pole post; the number of second protrusions is two, the two second protrusions are respectively located on both sides of the first protrusion.

3. The battery cell according to claim 1, characterized in that, The cover plate body has a reference surface, and the first support platform, the mounting platform and the second support platform protrude from the reference surface. The protrusion height of the first support platform and the second support platform relative to the reference surface is greater than the protrusion height of the end of the pole protruding from the mounting platform relative to the reference surface.

4. The battery cell according to any one of claims 1 to 3, characterized in that, The first support platform, the mounting platform, and the second support platform are connected to form an integral boss. The first sinker, the third sinker, and the second sinker are connected to form an integral sinker. The first convex hump and the second convex hump are connected to form a stepped convex hump. The protrusion height of the first convex hump is greater than the protrusion height of the second convex hump. The first convex hump is in a limiting fit with the first sinker.

5. The battery cell according to claim 4, characterized in that, The cell cover also includes an insulating component, which is disposed on the side of the cover body near the electrode assembly. The electrode post passes through the insulating component. A groove is formed on the side of the cover body near the electrode assembly corresponding to the position of the integrated boss. The insulating component and the groove are in concave-convex fit. The side of the insulating component away from the cover body corresponds to the position of the groove to form the integrated recessed groove.

6. The battery cell according to claim 4, characterized in that, The electrode assembly includes two electrode units, each electrode unit having a first end face and an electrode tab. The electrode tab is connected to the first end face, and the first end face has a protrusion. Each electrode unit has an inner side and an outer side facing away from each other in the width direction of the cover plate body. The protrusion is flush with the inner side and there is a gap between the protrusion and the outer side in the width direction. The inner sides of the two electrode units are in contact with each other, and the two protrusions facing away from each other in the width direction are in contact to form the stepped protrusion.

7. The battery cell according to claim 6, characterized in that, The distance between the protrusion and the outer side surface in the width direction is b, where 7mm ≤ b ≤ 15mm.

8. The battery cell according to claim 4, characterized in that, The cover plate body has a reference surface, the integral boss protrudes from the reference surface, the side wall of the integral boss and the reference surface form an angle of 90°+β, the side of the first protrusion and the connecting end face form an angle of 90°+θ, 15°≤β≤25°, 15°≤θ≤25°, -3≤θ-β≤3°; And / or, the assembly gap between the top surface of the stepped convex bulge and the integral recessed groove is c, 0.3mm≤c≤0.8mm, and the assembly gap between the side surface of the first convex bulge and the first recessed groove is d, 1.5mm≤d≤2.5mm. And / or, the distance between the two ends of the stepped convex bulge in the length direction and the edge of the pole group is G1, 35mm≤G1≤50mm.

9. The battery cell according to claim 1, characterized in that, The electrode lug has a root section and a closing section. The root section is connected to the connecting end face, and the closing section is connected to the end of the root section away from the connecting end face. The position where the root section and the closing section are connected is the closing position of the electrode lug. The distance between the outer side of the electrode assembly on one side of the cover plate body in the width direction and the closing position is a, where 1mm≤a≤3mm.

10. The battery cell according to claim 1, characterized in that, In the thickness direction of the cover plate body, the height of the first convex bulge relative to the connecting end face is H1, and the height of the second convex bulge relative to the connecting end face is H2, where 3.5mm≤H1-H2≤5mm.

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