Battery cell cover plate and battery cell

Abstract

The invention relates to the technical field of batteries, and provides a battery cell cover plate and a battery cell. The battery cell cover plate comprises a cover plate body, one side of the cover plate body is provided with a reference surface, a supporting boss and a mounting boss which are arranged in the length direction of the cover plate body are formed on the reference surface, and the supporting boss and the mounting boss are arranged on the reference surface in a protruding mode; the pole penetrates through the cover plate body, the first end of the pole protrudes out of the reference surface, and in the height direction of the cover plate body, the height of the supporting boss relative to the reference surface is larger than that of the pole protruding out of the reference surface; the insulating layer comprises a first insulating layer and a second insulating layer which are sequentially arranged on the side, away from the reference surface, of the cover plate body in a stacked mode. And after assembly, the tab can be actively pressed and fixed on the connecting part of the pole from one side. And direct clamping and fixing force is provided for the tab, so that the movement of the tab in the battery cell can be effectively limited, and the risk of fatigue fracture or cracking of the tab at the bending part or the welding printing area due to vibration and impact is remarkably reduced.

Description

Technical Field

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

[0002] Lithium-ion batteries have become crucial components in power batteries, energy storage devices, and other fields due to their high energy density and long cycle life. As the smallest unit of a lithium-ion battery, the reliability and safety of its internal structure are of paramount importance.

[0003] Traditional cover plate assemblies typically only have simple internal insulation components for insulation between the electrode post and the cover plate body. The tabs at the top of the electrode assembly are directly bent and welded to the lower end of the electrode post. In this structure, the welded tabs and their solder areas are completely exposed, lacking effective fixation and protection. When the cell is subjected to severe vibration, impact, or other external forces, the internal electrode assembly will shift. This shifting will directly generate tensile stress at the bend of the tabs and the solder area, which can easily lead to fatigue fracture of the tabs or cracking of the solder, thereby causing an internal short circuit and posing a safety threat. Summary of the Invention

[0004] This invention provides a cell cover plate and a cell to solve the problems that occur when the cell is subjected to severe vibration, impact or other external forces, the internal electrode assembly will move around, which can easily lead to fatigue fracture of the electrode tabs or cracking of the solder.

[0005] This invention provides a battery cell cover plate, comprising: The cover plate body has a reference surface on one side, on which a support boss and a mounting boss are formed along the length direction of the cover plate body, and the support boss and the mounting boss protrude from the reference surface; The pole extends through the cover plate body, with its first end protruding from the reference surface. In the height direction of the cover plate body, the height of the support boss relative to the reference surface is greater than the height of the pole protruding from the reference surface. The second end of the pole has a connecting portion for connecting with the electrode tab. The insulating layer includes a first insulating layer and a second insulating layer stacked sequentially on the side of the cover plate body facing away from the reference surface. The second end of the pole passes through the cover plate body and the first insulating layer, and its connecting portion is located between the first insulating layer and the second insulating layer. The side of the second insulating layer facing the first insulating layer abuts against the tab to press the tab tightly against the connecting portion of the pole.

[0006] According to the present invention, one of the first insulating layer and the second insulating layer is provided with a buckle, and the other is provided with a slot; The first insulating layer is connected to the second insulating layer by the buckle and the slot.

[0007] According to a battery cell cover plate provided by the present invention, the first insulating layer is provided with a first boss that is adapted to the shape of the support boss at the position corresponding to the support boss. The first insulating layer is assembled to the support boss through the first boss so as to be assembled to the side of the cover plate body away from the reference surface.

[0008] According to a battery cell cover provided by the present invention, two support bosses and two first insulating layers are provided. The two support bosses are located at both ends of the mounting boss along the length direction of the cover body. The two first insulating layers are assembled to the side of the cover body away from the reference surface through the corresponding first bosses. The two ends of the second insulating layer are respectively connected to the two first insulating layers. The second insulating layer is provided with a second boss corresponding to the mounting boss at the position of the mounting boss. The height of the second boss along the height direction of the cover plate body is flush with the first boss.

[0009] According to a battery cell cover plate provided by the present invention, the first insulating layer is provided with the slot, the second insulating layer is provided with the buckle, the slot width is Ф1, and the buckle width is Ф2, satisfying 1.2≤Ф2 / Ф1≤1.5.

[0010] According to a battery cell cover plate provided by the present invention, the thickness of the second insulating layer along the height direction of the cover plate body is t1, which satisfies 0.7mm≤t1≤1.2mm; The distance between the connecting part and the first insulating layer along the height direction of the cover plate body is a, which satisfies 0.2mm≤a≤0.5mm; The distance between the connecting part and the second insulating layer along the height direction of the cover plate body is b, which satisfies 0.7mm≤b≤1mm.

[0011] According to the present invention, the width of the cover body is W, which satisfies 25mm≤W≤75mm; The length of the first insulating layer along the width direction of the cover plate body is W1, which satisfies 22mm≤W1≤70mm; The length of the two ends of the second insulating layer along the width direction of the cover plate body is W2, and the length of the second boss along the width direction of the cover plate body is W3, satisfying: W2≤W1, 5mm≤(W1-W3) / 2≤10mm.

[0012] According to a battery cell cover provided by the present invention, the mounting boss is provided with a mounting groove, and the battery cell cover further includes: an explosion-proof valve disposed in the mounting groove; The mounting boss is provided with an exhaust notch communicating with the mounting groove; the second insulating layer is provided with a vent hole communicating with the mounting groove.

[0013] According to the present invention, a battery cell cover plate further includes: The first reinforcing rib is disposed on at least one side edge of the supporting boss and the mounting boss along the width direction of the cover plate body; The second reinforcing rib is disposed around the mounting boss corresponding to the explosion-proof valve.

[0014] The present invention also provides a battery cell, comprising: The battery cell casing has an opening; The aforementioned cell cover plate is disposed at the opening and surrounds the cell housing to form a receiving cavity; An electrode assembly is disposed within the receiving cavity, and the electrode tabs of the electrode assembly are connected to the electrode post.

[0015] The cell cover plate provided in this embodiment, by setting a first insulating layer and a second insulating layer, can actively press and fix the tab to the connection part of the terminal post from one side after assembly. This provides a direct clamping and fixing force to the tab, effectively limiting its movement within the cell and significantly reducing the risk of fatigue fracture or cracking of the tab at bending points or solder areas due to vibration or impact. This fundamentally improves the reliability of the internal connections of the cell and avoids safety hazards such as internal short circuits.

[0016] Furthermore, because the height of the support boss relative to the reference plane is greater than the height of the terminal post protruding from the reference plane, in the battery module or battery pack, when the upper casing is subjected to external impact or compression, the support boss will contact the upper casing before the terminal post, becoming the main force-bearing and support component. This effectively avoids the terminal post directly bearing excessive external force, greatly reducing the risk of internal short circuits caused by deformation or damage to the terminal post. Moreover, the support boss and the mounting boss together form the raised structure on the outer side of the cover plate body, significantly increasing the effective contact area between the cover plate and the upper casing of the battery pack. This allows the heat generated by the cell during operation to be directly conducted to the upper casing for heat dissipation through the large-area boss structure, transforming some of the original heat radiation heat dissipation into more efficient heat conduction heat dissipation, significantly improving the heat dissipation performance of the cell. 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 three-dimensional structural diagram of the battery cell cover plate provided by the present invention.

[0019] Figure 2 This is a schematic diagram of the first insulating layer and the second insulating layer provided by the present invention.

[0020] Figure 3 This is a schematic diagram of the pole installation provided by the present invention.

[0021] Figure 4 This is a disassembly diagram of the battery cell cover plate provided by the present invention.

[0022] Figure 5 This is a schematic diagram of the connection between the cell cover plate and the electrode assembly provided by the present invention.

[0023] Figure 6 This is a schematic diagram of the battery cell provided by the present invention.

[0024] Figure label: 1. Cell cover plate; 11. Cover plate body; 111. Reference surface; 112. Support boss; 113. Mounting boss; 114. Venting notch; 12. First reinforcing rib; 13. Second reinforcing rib; 14. First insulating layer; 141. Slot; 142. First boss; 15. Second insulating layer; 151. Buckle; 152. Second boss; 153. Vent hole; 16. Terminal post; 161. Connecting part; 17. Explosion-proof valve; 18. Riveting block; 19. Top plastic; 2. Battery cell casing; 3. Electrode group; 31. Electrode ear. Detailed Implementation

[0025] 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.

[0026] 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.

[0027] In some embodiments, such as Figures 1 to 5 As shown, the cell cover plate 1 includes: a cover plate body 11, a terminal post 16, and an insulating layer. One side of the cover plate body 11 has a reference surface 111. Support bosses 112 and mounting bosses 113 are formed on the reference surface 111, arranged along the length of the cover plate body 11. The support bosses 112 and mounting bosses 113 protrude from the reference surface 111. The terminal post 16 penetrates the cover plate body 11. The first end of the terminal post 16 protrudes from the reference surface 111. In the height direction of the cover plate body 11, the height of the support bosses 112 relative to the reference surface 111 is greater than the height of the terminal post 16 protruding from the reference surface 111. The second end of the terminal post 16 has a connecting portion 161 for connection with a tab 31.

[0028] See Figure 1 The cover plate body 11 has a length direction (x-axis) and a width direction (y-axis), and its height direction (z-axis) is perpendicular to the length and width directions and perpendicular to the reference surface 111. One side (generally the upper side) of the cover plate body 11 is defined as a flat reference surface 111. On this reference surface 111, support bosses 112 and mounting bosses 113 are integrally formed along the length direction of the cover plate body 11 through processes such as stamping.

[0029] In this embodiment, the insulating layer is a lower plastic, and the battery cell cover plate 1 is provided with an upper plastic 19 on one side of the reference surface 111. The reference surface 111 is generally provided with a positioning groove, and the upper plastic 19 is provided in the positioning groove. The two ends of the pole post 16 are provided with the upper plastic 19, the cover plate body 11 and the lower plastic. A riveting block 18 connected to the pole post 16 can be provided in the upper plastic 19.

[0030] The lower plastic includes a first insulating layer 14 and a second insulating layer 15 that are stacked and detachably disposed on the side of the cover plate body 11 away from the reference surface 111. The second end of the pole post 16 passes through the cover plate body 11 and the first insulating layer 14, and its connecting portion 161 is located between the first insulating layer 14 and the second insulating layer 15. The side of the second insulating layer 15 facing the first insulating layer 14 abuts against the tab 31 to press the tab 31 tightly against the connecting portion 161 of the pole post 16.

[0031] Specifically, during the cell assembly and welding stage, the first insulating layer 14 is aligned and installed onto the inner side of the cover plate body 11. At this time, the second end of the electrode post 16 passes through the corresponding through hole on the first insulating layer 14, so that its connection part 161 is completely exposed outside the first insulating layer 14. The first insulating layer 14 can be detachably and initially fixed to the cover plate body 11 by means of a snap-fit ​​151, bolts, or other preset positioning features.

[0032] Then, the tabs 31 of the electrode assembly 3 (usually a laminate of aluminum or copper foil) are guided to the second end of the pole post 16. The ends of the tabs 31 are bent and shaped to make them flat and fixed to the connecting part 161 of the pole post 16. The fixing method usually adopts processes such as laser welding and ultrasonic welding to form a strong electrical and mechanical connection.

[0033] Finally, the second insulating layer 15 is aligned and covered over the area where the tab 31 has been soldered. During assembly, the inner surface of the second insulating layer 15 directly contacts and presses against the tab 31 and the solder area. By pressing the second insulating layer 15 and utilizing its detachable connection structure with the first insulating layer 14 or the cover plate body 11, the tab 31 is tightly pressed between the connection portion 161 of the pole post 16 and the second insulating layer 15. After locking, the continuous clamping force provided by the second insulating layer 15 effectively restrains the tab 31, preventing it from shifting or fatigued due to vibration during subsequent use. At the same time, the side of the second insulating layer 15 facing the first insulating layer 14 abuts against the second end of the pole post 16, which also secures the pole post 16.

[0034] Throughout the entire lifespan of the battery cell, the first insulating layer 14 and the second insulating layer 15 remain in a pressed state. This ensures that the tab 31 and the terminal post 16 are always in a protected and fixed environment, which not only improves the mechanical stability of the welding point but also enhances the long-term reliability of the battery cell under harsh operating conditions.

[0035] The cell cover 1 provided in this embodiment, by providing a detachable first insulating layer 14 and a second insulating layer 15, can actively press and fix the tab 31 to the connection part 161 of the pole post 16 from one side after assembly. This provides a direct clamping force for the tab 31, effectively limiting its movement within the cell and significantly reducing the risk of fatigue fracture or cracking of the tab 31 at bending points or solder areas due to vibration or impact. This fundamentally improves the reliability of the internal connections of the cell and avoids potential safety hazards such as internal short circuits.

[0036] Furthermore, since the height of the support boss 112 relative to the reference surface 111 is greater than the height of the terminal post 16 protruding from the reference surface 111, in the battery module or battery pack, when the upper casing is subjected to external impact or compression, the support boss 112 will contact the upper casing before the terminal post 16, becoming the main force-bearing and support component. This effectively avoids the terminal post 16 directly bearing excessive external force, greatly reducing the risk of internal short circuits caused by deformation or damage to the terminal post 16 under stress. Moreover, the support boss 112 and the mounting boss 113 together constitute the raised structure on the outer side of the cover plate body 11, significantly increasing the effective contact area between the cover plate and the upper casing of the battery pack. This allows the heat generated by the cell during operation to be directly conducted to the upper casing for heat dissipation through the large-area boss structure, transforming some of the original heat radiation heat dissipation into more efficient heat conduction heat dissipation, significantly improving the heat dissipation performance of the cell.

[0037] In some embodiments, such as Figure 2 As shown, one of the first insulating layer 14 and the second insulating layer 15 is provided with a buckle 151, and the other is provided with a slot 141; the first insulating layer 14 is detachably connected to the second insulating layer 15 through the buckle 151 and the slot 141.

[0038] As a preferred embodiment, a slot 141 can be formed on the first insulating layer 14, and a buckle 151 that cooperates with the slot 141 can be integrally formed or assembled on the second insulating layer 15.

[0039] The arrangement of the snap fasteners 151 and slots 141 can be designed and adjusted according to the shape, size, and stress requirements of the insulation layer. Typically, they are spaced apart along the joint edges of the first insulation layer 14 and the second insulation layer 15 to ensure uniform and stable connection force. For example, slots 141 can be provided at the two corners of the first insulation layer 14. The snap fastener 151 can be a cantilevered hook with elastic recovery capability, a spherical locking point, or a boss-like structure. Its root is connected to the body of the second insulation layer 15, and its head has a guide ramp and a locking step, facilitating insertion and locking within the slot 141 during assembly. The corresponding slot 141 has a cavity matching the shape of the snap fastener 151's head. After the snap fastener 151 is fully engaged, its locking step hooks with the limiting surface within the slot 141, thereby restraining their separation in the height direction.

[0040] During assembly, the operator roughly aligns the latch 151 on the second insulating layer 15 with the slot 141 on the first insulating layer 14, applies pressure to cause the head of the latch 151 to elastically deform along the guide ramp and slide into the slot 141 until the latch 151 is fully in place, at which point the locking step engages with the slot 141. During disassembly, a reverse force is applied to disengage the latch 151 from the slot 141, thus separating the first insulating layer 14 and the second insulating layer 15 without damage.

[0041] The detachable connection scheme of the buckle 151-slot 141 not only realizes the quick assembly and disassembly between the two insulating parts, which facilitates the inspection and maintenance of the electrode 31 after welding, but also provides a stable downward pressure for the second insulating layer 15 after locking, ensuring that it can continuously press the electrode 31 onto the electrode post 16 connection part 161.

[0042] In this embodiment, the first insulating layer 14 has a first boss 142 that matches the shape of the support boss 112 at the position corresponding to the support boss 112. The first insulating layer 14 is assembled to the support boss 112 via the first boss 142, so as to be detachably assembled to the side of the cover plate body 11 away from the reference surface 111. During assembly, by directly fitting or embedding the first boss 142 on the first insulating layer 14 into the corresponding support boss 112 on the cover plate body 11, the first insulating layer 14 can be positioned in the vertical direction and limited in the horizontal direction. This not only allows the first insulating layer 14 to be quickly and accurately aligned and installed to the side of the cover plate body 11 away from the reference surface 111, but also achieves preliminary fixation of the two in the direction perpendicular to the plane of the cover plate through structural interference, forming a detachable assembly relationship.

[0043] In some embodiments, such as Figures 1 to 4As shown, two support bosses 112 and two first insulating layers 14 are provided. The two support bosses 112 are distributed along the length direction of the cover plate body 11 and are located at both ends of the mounting boss 113 along the length direction of the cover plate body 11. Correspondingly, the two first insulating layers 14 are aligned and assembled onto the corresponding support bosses 112 through their respective first bosses 142, thereby fixing them to the side of the cover plate body 11 away from the reference surface 111. This split design allows each first insulating layer 14 to be installed and positioned independently, which is convenient for adapting to pole posts 16 or other components at different positions on the cover plate body 11. The second insulating layer 15 is a connecting and covering member. Its two ends along its length are respectively connected to the two first insulating layers 14 by a detachable means (such as the aforementioned buckle 151-slot 141), thereby spanning and covering the area between the two first insulating layers 14. To further enhance the stability and positioning accuracy of the overall structure, a second protrusion 152 is provided on the side of the second insulating layer 15 facing the cover plate body 11, corresponding to the mounting protrusion 113. The height of the second protrusion 152 along the height direction of the cover plate body 11 is flush with that of the first protrusion 142. When the first insulating layer 14 is assembled to the supporting protrusion 112 through its first protrusion 142, and the second insulating layer 15 is simultaneously assembled on the first insulating layer 14, the first protrusion 142 and the second protrusion 152 are flush in height, and the first insulating layer 14 and the second insulating layer 15 can form a continuous and flat support on the side facing the cover plate body 11.

[0044] In some embodiments, such as Figure 1 and Figure 2 As shown, the first insulating layer 14 is provided with a slot 141, and the second insulating layer 15 is provided with a buckle 151. Generally, the slot 141 is designed as a circular slot, and correspondingly, the buckle 151 adopts a cylindrical structure. This circular fit allows the buckle 151 to be subjected to uniform circumferential force during insertion into the slot 141, making it easy to guide and assemble, while also providing reliable circumferential constraint.

[0045] To ensure the connection is secure and the assembly is feasible, the diameter of the slot 141 is denoted as Ф1 and the diameter of the buckle 151 is denoted as Ф2. The two must satisfy the following ratio: 1.2≤Ф2 / Ф1≤1.5.

[0046] This proportion of interference ensures that the latch 151 generates sufficient elastic deformation and radial clamping force after being pressed into the latch groove 141. This clamping force is transmitted through the second insulating layer 15 and ultimately acts on the tab 31 below it.

[0047] If the ratio is too low (Ф2 / Ф1<1.2), the interference fit will be insufficient, which may lead to loose engagement, reduced clamping force, and abnormal noise or failure under vibration. If the ratio is too high (Ф2 / Ф1>1.5), the assembly resistance will be too high, which may not only cause assembly difficulties, but may even cause irreversible plastic deformation or cracking of the plastic parts around the snap 151 or the slot 141, affecting the connection life and sealing insulation performance.

[0048] In some embodiments, such as Figure 2 and Figure 3 As shown, key dimensions were optimized to ensure the mechanical strength of the insulation layer, the reliable crimping of the tabs 31, and the feasibility of assembly.

[0049] Specifically, the thickness of the second insulating layer 15 along the height direction (i.e., the height direction) of the cover plate body 11 is defined as t1, and its value range satisfies 0.7mm≤t1≤1.2mm. This thickness range ensures that the second insulating layer 15 has sufficient structural rigidity and resistance to deformation, so that the required clamping force can be applied to the tab 31 stably and uniformly after locking, without excessively increasing the overall weight and space occupation.

[0050] Furthermore, in the assembled state, there is a gap, defined as a, between the upper surface of the connecting part 161 of the pole post 16 (i.e. the welding or connection area with the pole tab 31) and the surface of the first insulating layer 14 facing the connecting part 161, along the height direction of the cover plate body 11, and its value range satisfies 0.2mm≤a≤0.5mm.

[0051] Similarly, after assembly is completed and the second insulating layer 15 is locked, there is also a designed gap, defined as b, between the lower surface of the connecting part 161 of the pole post 16 and the second insulating layer 15 along the height direction of the cover plate body 11. The value of b is within the range of 0.7mm≤b≤1mm. Since there is a tab 31 between the connecting part 161 and the second insulating layer 15, this space is mainly used to accommodate the pressed tab 31 and its solder mark. When the value of b is within this optimized range, it can be ensured that the second insulating layer 15 can generate sufficient and uniform pre-pressure on the tab 31 after locking, thereby effectively limiting its movement; at the same time, this space also provides a buffer for component deformation, preventing damage to the tab 31 or stress cracking of the insulating layer due to excessive pressure.

[0052] In some embodiments, such as Figures 1 to 5 The cover plate body 11 shown has a width of W and a length of L, satisfying 25mm≤W≤75mm and 150mm≤L≤300mm. This size range defines the common specifications of battery cells to which the cover plate is applicable, enabling it to adapt to different batteries from small to large.

[0053] The length of the first insulating layer 14 along the width direction of the cover plate body 11 is W1, which satisfies 22mm≤W1≤70mm; W1 is usually slightly smaller than the width W of the cover plate body 11, in order to ensure that when the first insulating layer 14 is installed in the center inside the cover plate, the necessary safety distance can be reserved between its two side edges and the inner sidewall of the cover plate body 11.

[0054] The lengths of the two ends of the second insulating layer 15 along the width direction of the cover plate body 11 are W2, the length of the second boss 152 along the width direction of the cover plate body 11 is W3, and the distance between the bosses of the two pole groups 3 is W4, satisfying: W2≤W1, 5mm≤(W1-W3) / 2≤10mm, 2mm≤(W4-W3) / 2≤3mm.

[0055] Satisfying W2≤W1 ensures that both ends of the second insulating layer 15 can be fully supported and carried by the first insulating layer 14 in the width direction, ensuring the stability of the connection interface and uniform stress.

[0056] The requirement is that 5mm ≤ (W1-W3) / 2 ≤ 10mm, where (W1-W3) / 2 is the length of the non-protrusion portion at each end of the second insulating layer 15 overhanging relative to its own second protrusion 152 after the second insulating layer 15 is assembled with the first insulating layer 14. Controlling the overhang on one side to between 5mm and 10mm ensures that the two ends of the second insulating layer 15 have sufficient length to effectively cover and press the connection area of ​​the tab 31 below, providing a stable pressing force distribution. If the overhang is too small, the pressing may be insufficient, affecting the fixing effect; if the overhang is too large, it is prone to deformation or vibration under vibration.

[0057] The requirement of 2mm ≤ (W4-W3) / 2 ≤ 3mm is met. The physical meaning of (W4-W3) / 2 is the single-sided assembly gap reserved between each side of the second boss 152 and its corresponding side of the pole group 3 boss when the second boss 152 is assembled between the two pole group 3 bosses. This gap ensures that the second boss 152 can still be smoothly inserted, avoiding assembly difficulties; it also prevents excessive movement or misalignment of the second insulating layer 15 in the width direction due to an excessively large gap, thus ensuring structural stability.

[0058] In some embodiments, such as Figures 1 to 4 As shown, the mounting boss 113 has a mounting groove, and the cell cover plate 1 also includes an explosion-proof valve 17. The explosion-proof valve 17 is disposed in the mounting groove. The mounting boss 113 has an exhaust notch 114 communicating with the mounting groove, and the first insulating layer 14 has a vent hole 153 communicating with the mounting groove.

[0059] In this embodiment, the mounting boss 113 has a recessed mounting groove machined on its top platform (i.e., the surface protruding from the reference surface 111). This mounting groove is used to accommodate and fix the explosion-proof valve 17. The explosion-proof valve 17 is typically a thin sheet-like metal valve body, the edges of which are sealed and fixed to the bottom or side wall of the mounting groove by processes such as laser welding, riveting, or bonding. The connecting part 161 is a connecting piece. The connecting piece is located on the side of the cover plate body 11 facing away from the reference surface 111. One end of the connecting piece is connected to the second end of the pole post 16, and the other end of the connecting piece extends to connect with the tab 31.

[0060] To achieve directional pressure release, one or more venting notches 114 are provided on the side wall of the mounting boss 113. Each venting notch 114 is an opening or groove penetrating the side wall of the mounting boss 113, with its lower end communicating with the internal space of the mounting groove. When the explosion-proof valve 17 ruptures or opens due to excessive internal pressure in the battery cell, the resulting high-temperature, high-pressure gas will first rush into the mounting groove where it is located.

[0061] To effectively guide the internal pressure of the battery cell to the explosion-proof valve 17, a vent hole 153 is correspondingly provided on the first insulating layer 14 located on the inner side of the cover plate. The vent hole 153 is a hole that penetrates the first insulating layer 14. The vent hole 153 ensures that the gas passage between the internal space of the battery cell and the cavity where the explosion-proof valve 17 is located is unobstructed.

[0062] When a battery cell experiences thermal runaway or other abnormal conditions, internal gas production causes a rapid increase in pressure. The high-pressure gas passes through the vent 153 on the first insulation layer 14 and rapidly acts on the back of the explosion-proof valve 17. When the pressure exceeds the preset burst pressure threshold of the explosion-proof valve 17, the valve body ruptures or deforms at the mounting groove, opening the valve. The high-pressure gas instantly bursts through the explosion-proof valve 17, enters the mounting groove space, and is then discharged laterally rather than directly upwards into the external environment of the battery cell through the vent 114 on the side wall of the mounting boss 113. Typically, multiple vents 153 are provided; these holes are not evenly distributed but are concentrated in the area below the mounting groove of the corresponding explosion-proof valve 17 to create a pressure relief channel.

[0063] In this embodiment, the cell cover plate 1 further includes: a first reinforcing rib 12 and a second reinforcing rib 13. The first reinforcing rib 12 is disposed on at least one side edge of the supporting boss 112 and the mounting boss 113 along the width direction of the cover plate body 11; the second reinforcing rib 13 is disposed around the mounting boss 113 corresponding to the explosion-proof valve 17.

[0064] There are two supporting bosses 112, and a mounting boss 113 is located between these two supporting bosses 112, thereby forming a continuous boss array of "supporting boss 112, mounting boss 113, supporting boss 112" along the length of the cover plate body 11. The reinforcing ribs include two first reinforcing ribs 12, which are continuously disposed on the two outer edges of the aforementioned boss array along the width direction of the cover plate body 11.

[0065] Each first reinforcing rib 12 starts from the side edge of the supporting boss 112 at one end, extends continuously through the corresponding side edge of the mounting boss 113, and finally reaches the side edge of the supporting boss 112 at the other end, thus forming a continuous reinforcing frame between the two bosses. The continuously extending first reinforcing ribs 12 structurally connect the originally independent supporting bosses 112 and mounting bosses 113 into a whole, greatly enhancing the overall rigidity and bending resistance of the cover plate in the length direction. When the cell cover plate 1 is subjected to external loads, the reinforcing rib can effectively transfer and disperse the stress smoothly along its length direction, avoiding stress concentration at the boss connection, and improving the impact resistance and fatigue resistance of the cell cover plate 1.

[0066] The second reinforcing rib 13 is disposed around the periphery of the mounting boss 113 corresponding to the explosion-proof valve 17. This second reinforcing rib 13 can be a closed annular frame structure, or it can be composed of several discrete rib segments distributed on both sides or around the explosion-proof valve 17. Its function is to provide localized reinforcement to the mounting area of ​​the explosion-proof valve 17 from the side. The second reinforcing rib 13 can provide effective support and protection for the explosion-proof valve 17 and the local area of ​​the mounting boss 113. When subjected to external compression or internal pressure impact, the second reinforcing rib 13 can significantly enhance the deformation resistance of the mounting boss 113, preventing the collapse or warping of the mounting boss 113 from adversely affecting the weld sealing of the explosion-proof valve 17, thereby ensuring that the explosion-proof valve 17 is reliably triggered under predetermined operating conditions.

[0067] In some embodiments, such as Figures 1 to 6 As shown, there are two support bosses 112. These two support bosses 112 are not isolated but are located at opposite ends of the mounting boss 113 along the length of the cover plate body 11. Each support boss 112 has a top surface with an adhesive application area. The cell cover plate 1 also includes structural adhesive, which is applied to the adhesive application area. After curing, the final height of the structural adhesive relative to the reference surface 111 is controlled to be greater than the height of the top surface of the mounting boss 113 relative to the reference surface 111, so that it can abut against the external structure through the structural adhesive and reinforcing ribs.

[0068] When the cell cover 1 is assembled with the upper casing and other external structures, the upper casing will first contact and press against the upper surface of the structural adhesive due to the maximum height of the structural adhesive. This allows external loads (such as compression and vibration impact) to be preferentially transferred through the buffering structural adhesive to the mechanically strong support boss 112 and its continuous reinforcing rib network, and finally distributed throughout the entire cover body 11. This bypasses the relatively fragile mounting boss 113 and its explosion-proof valve 17, as well as the reference surface 111 area where the pole post 16 is welded, thus protecting critical safety components.

[0069] Meanwhile, the top surface of the supporting boss 112, the top surface of the reinforcing ribs thereon, and the structural adhesive filling them together constitute an effective heat transfer interface. The heat generated by the battery cell can be efficiently conducted to the upper casing with extremely low thermal resistance through this interface, where the upper casing acts as a heat sink to dissipate the heat. This significantly improves the heat dissipation capacity of the battery pack.

[0070] like Figure 6 As shown, this embodiment of the invention also provides a battery cell, including: a battery cell housing 2, a battery cell cover plate 1, and the battery cell cover plate 1 of any of the above embodiments.

[0071] In this embodiment, the cell housing 2 is typically a hollow structure made of metal materials such as aluminum, aluminum alloy, or stainless steel, with an opening at one end to accommodate the electrode assembly 3 and the electrolyte. The cell cover plate 1 is sealed by welding (e.g., laser welding) to the edge of the opening in the cell housing 2, thereby closing the opening and forming a sealed cavity together with the cell housing 2. The tabs 31 on the electrode assembly 3 are electrically connected to the corresponding terminals 16 within the cavity.

[0072] In one specific embodiment, as shown in Table 1 below, the slot width is Ф1, the buckle width is Ф2, the thickness of the second insulating layer along the height direction of the cover plate body is t1, the distance between the connecting part and the first insulating layer along the height direction of the cover plate body is a, the distance between the connecting part and the second insulating layer along the height direction of the cover plate body is b, the width of the cover plate body is W, the length of the first insulating layer along the width direction of the cover plate body is W1, the length of both ends of the second insulating layer along the width direction of the cover plate body is W2, the length of the second boss along the width direction of the cover plate body is W3, and the distance between the bosses of the two pole groups is W4.

[0073] Table 1 Example 1 Ф1 (mm) Ф2 (mm) t1 (mm) t2 (mm) a (mm) b (mm) W1 (mm) W2 (mm) W3 (mm) W4 (mm) Ф2 / Ф1 (W1-W3) / 2 (mm) (W4-W3) / 2 (mm) Example 2 3.6 4.5 0.8 0.7 0.2 0.7 22 20 12.0 16.0 1.25 5.0 2.0 Example 3 3.2 4.5 0.85 0.75 0.25 0.75 25 24 12.0 17.0 1.41 6.5 2.5 Example 4 3.6 4.8 0.9 0.8 0.3 0.8 28 26 12.0 18.0 1.33 8.0 3.0 Example 5 4.5 5.5 0.95 0.85 0.35 0.85 35 32 15.0 20.0 1.22 10.0 2.5 Example 6 4.2 5.5 1 0.9 0.4 0.8 40 38 22.0 26.0 1.31 9.0 2.0 Example 7 3.8 5.5 1.05 0.95 0.45 0.9 48 45 34.0 39.0 1.45 7.0 2.5 Example 8 3.6 5 1.1 1 0.5 0.95 54 50 38.0 44.0 1.39 8.0 3.0 Example 9 4 5 1.2 1.2 0.4 1 68 65 55.0 60.0 1.25 6.5 2.5 Comparative Example 1 3.6 4.5 0.8 0.65 0.2 0.7 22 20 12.0 16.0 1.25 5.0 2.0 Comparative Example 2 4.2 5.5 1 0.9 0.4 0.65 40 38 22.0 26.0 1.31 9.0 2.0 Comparative Example 3 4.2 5.5 1 0.9 0.4 0.8 40 38 23.0 26.0 1.31 8.5 1.5 The core parameters of all embodiments (1-8), including Ф2 / Ф1 (1.22~1.45), (W1-W3) / 2 (5.0~10.0 mm), (W4-W3) / 2 (2.0~3.0 mm), b (0.7~1.0 mm), and t1 (0.8~1.2 mm), strictly meet or are within the optimal range of the aforementioned design requirements. The corresponding verification results all show that the structural strength meets the standards, the assembly is smooth, the fixing effect is excellent, and the vibration test is passed. There is no displacement of the pole group and no damage to the pole tabs, which fully verifies the achievement of the design goals.

[0074] Comparative Example 1: Although the main dimensional ratios are the same as in Example 1, the thickness of the underlying plastic is below the safety threshold. The thickness of the first and second insulating layers is also a key factor in ensuring the overall rigidity of the structure, preventing production deformation and assembly problems, and its thickness must match the overall dimensions.

[0075] Comparative Example 2: Parameter b (the distance between the connector and the second insulating layer) is only 0.65 mm, lower than the lower limit of 0.7 mm. This results in insufficient vertical space for accommodating the tab and its solder mark, causing excessive pressure on the tab after the second insulating layer is assembled. Although the fixing effect may be enhanced, excessive clamping force can easily damage the extremely thin tab or cause stress concentration in the solder mark area, posing a safety hazard.

[0076] Comparative Example 3: The parameter (W4-W3) / 2 (the single-sided gap between the electrode group boss and the second insulation layer boss) is only 1.5mm, less than the lower limit of 2mm. This results in an excessively small assembly tolerance. In actual assembly, even equipment positioning deviations may cause interference between the second boss of the second insulation layer and the electrode group boss. Forced assembly will damage or scratch the electrode group, harming the cell components.

[0077] 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 cover plate, characterized in that, include: The cover plate body has a reference surface on one side, on which a support boss and a mounting boss are formed along the length direction of the cover plate body, and the support boss and the mounting boss protrude from the reference surface; The pole extends through the cover plate body, with its first end protruding from the reference surface. In the height direction of the cover plate body, the height of the support boss relative to the reference surface is greater than the height of the pole protruding from the reference surface. The second end of the pole has a connecting portion for connecting with the electrode tab. The insulating layer includes a first insulating layer and a second insulating layer stacked sequentially on the side of the cover plate body facing away from the reference surface. The second end of the pole passes through the cover plate body and the first insulating layer, and its connecting portion is located between the first insulating layer and the second insulating layer. The side of the second insulating layer facing the first insulating layer abuts against the tab to press the tab tightly against the connecting portion of the pole.

2. The cell cover plate according to claim 1, characterized in that, One of the first insulating layer and the second insulating layer is provided with a buckle, and the other is provided with a slot; The first insulating layer is connected to the second insulating layer by the buckle and the slot.

3. The cell cover plate according to claim 2, characterized in that, The first insulating layer has a first boss that matches the shape of the support boss at the position corresponding to the support boss. The first insulating layer is assembled to the support boss through the first boss so as to be assembled to the side of the cover plate body away from the reference surface.

4. The cell cover plate according to claim 3, characterized in that, Both the support boss and the first insulating layer are provided in twos. The two support bosses are located at both ends of the mounting boss along the length direction of the cover plate body. The two first insulating layers are assembled to the side of the cover plate body away from the reference surface through the corresponding first bosses. The two ends of the second insulating layer are respectively connected to the two first insulating layers. The second insulating layer is provided with a second boss corresponding to the mounting boss at the position of the mounting boss. The height of the second boss along the height direction of the cover plate body is flush with the first boss.

5. The cell cover plate according to claim 2, characterized in that, The first insulating layer is provided with the slot, and the second insulating layer is provided with the buckle. The slot width is Ф1, and the buckle width is Ф2, satisfying 1.2≤Ф2 / Ф1≤1.

5.

6. The cell cover plate according to claim 1, characterized in that, The thickness of the second insulating layer along the height direction of the cover plate body is t1, which satisfies 0.7mm≤t1≤1.2mm; The distance between the connecting part and the first insulating layer along the height direction of the cover plate body is a, which satisfies 0.2mm≤a≤0.5mm; The distance between the connecting part and the second insulating layer along the height direction of the cover plate body is b, which satisfies 0.7mm≤b≤1mm.

7. The cell cover plate according to claim 4, characterized in that, The width of the cover plate body is W, which satisfies 25mm≤W≤75mm; The length of the first insulating layer along the width direction of the cover plate body is W1, which satisfies 22mm≤W1≤70mm; The length of the two ends of the second insulating layer along the width direction of the cover plate body is W2, and the length of the second boss along the width direction of the cover plate body is W3, satisfying: W2≤W1, 5mm≤(W1-W3) / 2≤10mm.

8. The cell cover plate according to claim 1, characterized in that, The mounting boss is provided with a mounting groove, and the battery cell cover plate further includes an explosion-proof valve, which is disposed in the mounting groove; The mounting boss is provided with an exhaust notch communicating with the mounting groove; the second insulating layer is provided with a vent hole communicating with the mounting groove.

9. The cell cover plate according to claim 8, characterized in that, The cell cover plate also includes: The first reinforcing rib is disposed on at least one side edge of the supporting boss and the mounting boss along the width direction of the cover plate body; The second reinforcing rib is disposed around the mounting boss corresponding to the explosion-proof valve.

10. A battery cell, characterized in that, include: The battery cell casing has an opening; The cell cover plate as described in any one of claims 1 to 9, wherein the cell cover plate is disposed at the opening and surrounds the cell housing to form a receiving cavity; An electrode assembly is disposed within the receiving cavity, and the electrode tabs of the electrode assembly are connected to the electrode post.

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