Battery cell cover plate and battery cell
By designing a rotatable protective structure and supporting boss on the cell cover, the problem of the electrode assembly shifting under vibration or impact is solved, achieving stable fixing of the electrode tabs and improved heat dissipation performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-03
- Publication Date
- 2026-05-19
AI Technical Summary
Under severe vibration or impact, the electrode assembly of traditional battery cell covers is prone to shifting, leading to fatigue fracture of the electrode tabs or cracking of the solder joints, which poses a safety hazard.
Design a cell cover plate comprising a rotatable protective structure and a support boss. The protective structure covers and presses the tabs after welding, and the support boss bears the main force when the pole is under stress, thereby increasing the contact area between the cover plate and the battery pack to improve heat dissipation.
It effectively prevents damage to the tabs and solder joints under harsh working conditions, reduces the risk of internal short circuits, and improves the mechanical stability and heat dissipation performance of the battery cell.
Smart Images
Figure CN122068192A_ABST
Abstract
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 is used to connect with the electrode tab. The protective structure is rotatably connected to the side of the cover plate body opposite to the reference surface, and has an open state and a closed state. In the open state, the protective structure is separated from the tab; in the pressed state, the protective structure covers and presses against the tab to fix the tab and connect to the second end of the pole post.
[0006] According to the present invention, a battery cell cover plate further includes: an insulating layer disposed on the side of the cover plate body opposite to the reference surface; The protective structure includes: a fixing part and a folding part; The fixing part is disposed on the side of the insulating layer opposite to the cover plate body; the folding part is rotatably connected to the fixing part; In the open state, the folded portion is separated from the tab; in the pressed state, the folded portion covers and presses against the tab to fix the tab and connect to the pole post.
[0007] According to a battery cell cover provided by the present invention, the battery cell cover further includes: a connecting piece disposed on the side of the cover body opposite to the reference surface, one end of the connecting piece being connected to the second end of the electrode post, and the other end of the connecting piece extending to be connected to the electrode tab.
[0008] According to the present invention, the distance between the fixing part and the insulating layer along the height direction of the cover body is H1, where 0.5mm≤H1≤1mm; In the pressed state, the distance between the rotating position of the folded part and the pole post along the height direction of the cover plate body is H2, the wall thickness of the folded part is t1, the wall thickness of the connecting piece is t2, and 0.2mm≤H2-t1-t2≤0.5mm.
[0009] According to the present invention, the distance between the fixing part and the connecting piece along the length direction of the cover body is A, where 1mm≤A≤3mm; The connecting piece includes: a first part and a second part that are connected to each other, the first part being connected to the second end of the pole post, and the second part being connected to the pole tab; When the protective structure is in a pressed state, the distance between the folded part and the first part along the length direction of the cover plate body is B, where 2mm≤B≤5mm.
[0010] According to the present invention, a battery cell cover plate is provided, wherein the connecting piece is provided with two electrode welding stations arranged along the width direction of the cover plate body; the distance between the outermost two electrode welding stations along the width direction of the cover plate body is W0, and the width of the folded part along the width direction of the cover plate body is W1, 2mm≤(W1-W0) / 2≤3.5mm.
[0011] 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 at least one venting notch that communicates with the mounting groove.
[0012] 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.
[0013] According to a battery cell cover plate provided by the present invention, two supporting bosses are provided, and the two supporting bosses are located at both ends of the mounting boss along the length direction of the cover plate body; The support boss is provided with an adhesive application area; The cell cover plate further includes: structural adhesive, disposed in the adhesive application area; along the height direction of the cover plate body, the height of the structural adhesive relative to the reference surface is greater than the height of the mounting boss relative to the reference surface, so as to abut against the external structure through the structural adhesive.
[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 provided in this embodiment features a rotatable protective structure that switches from an open to a closed state after the tabs are welded. This protective structure actively covers and presses against the tabs and their connection points with the terminals. This provides effective mechanical fixation and protection for the tabs, preventing them from shifting and pulling under harsh conditions such as vibration and impact, thus avoiding fatigue fracture of the tabs or cracking of the solder joints.
[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 three-dimensional structural diagram of the back of the battery cell cover provided by the present invention.
[0020] Figure 3 This is a schematic diagram of the back side of the battery cell cover provided by the present invention.
[0021] Figure 4 yes Figure 3 A cross-sectional diagram at position CC.
[0022] Figure 5 This is one of the schematic diagrams showing the connection between the cell cover plate and the electrode assembly provided by the present invention.
[0023] Figure 6 This is the second schematic diagram of the connection between the cell cover plate and the electrode assembly provided by the present invention.
[0024] Figure 7 This is a schematic diagram of the battery cell provided by the present invention.
[0025] Figure label: 1. Cell cover plate; 11. Cover plate body; 111. Reference surface; 112. Support boss; 113. Mounting boss; 12. First reinforcing rib; 121. First venting notch; 13. Second reinforcing rib; 131. Second venting notch; 14. Protective structure; 141. Fixing part; 142. Folding part; 15. Explosion-proof valve; 16. Pole post; 17. Connecting piece; 171. Pole lug welding station; 18. Insulation layer; 2. Cell casing; 3. Electrode assembly; 31. Electrode tab. Detailed Implementation
[0026] 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.
[0027] 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.
[0028] The following is combined Figures 1-7 The present invention describes the cell cover plate 1 and the cell provided by the present invention.
[0029] In some embodiments, such as Figures 1 to 6 As shown, the cell cover 1 includes: a cover body 11, a terminal post 16, and a protective structure 14. One side of the cover 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 body 11. The support bosses 112 and mounting bosses 113 protrude from the reference surface 111. The terminal post 16 penetrates the cover body 11, with its first end protruding from the reference surface 111. In the height direction of the cover 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 is used to connect to the second end of the tab 31.
[0030] 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.
[0031] In this embodiment, the protective structure 14 is rotatably connected to the side of the cover plate body 11 away from the reference surface 111, and has an open state and a pressed state. In the open state, the protective structure 14 rotates to separate from the electrode tab 31, which facilitates the welding of the electrode tab 31 to the electrode post 16. In the pressed state, the protective structure 14 rotates to cover and press against the electrode tab 31 to fix the electrode tab 31 and connect it to the electrode post 16.
[0032] Specifically, during the cell assembly stage, the protective structure 14 is in the open position. At this time, the movable part of the protective structure 14 flips upward, providing ample and unobstructed working space for the welding operation between the tab 31 and the terminal post 16. The operator can easily guide and position the tab 31 to the connection point of the terminal post 16 to complete the welding.
[0033] After welding, the protective structure 14 is rotated to the pressed state. At this time, the movable part of the protective structure 14 covers the tab 31 and its solder joint, and applies appropriate clamping force. This action firstly firmly presses the tab 31 onto the pole post 16, effectively preventing the tab 31 from shifting or loosening due to vibration or impact during the use of the battery cell; secondly, it protects the connection part of the tab 31 from external mechanical interference, reducing the risk of the tab 31 tearing or the solder joint cracking due to the movement of the pole group 3.
[0034] Throughout the entire lifespan of the battery cell, the protective structure 14 remains in a pressed-in state. This ensures that the connection point between the tab 31 and the terminal post 16 is always protected and secured, 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 battery cell cover 1 provided in this embodiment features a rotatable protective structure 14. After the tabs 31 are welded, the protective structure 14 switches from an open state to a closed state. This protective structure 14 actively covers and presses against the tabs 31 and their connection points with the terminal posts 16. This provides effective mechanical fixation and protection for the tabs 31, preventing them from shifting and pulling on the tabs 31 under harsh conditions such as vibration and impact, thus avoiding fatigue fracture of the tabs 31 or cracking of the solder joints.
[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 Figures 2 to 6As shown, the cell cover 1 also includes an insulating layer 18. The insulating layer 18 is disposed on the side of the cover body 11 facing away from the reference surface 111; the protective structure 14 includes a fixing part 141 and a folding part 142; the fixing part 141 is disposed on the side of the insulating layer 18 facing away from the cover body 11; the folding part 142 is rotatably connected to the fixing part 141; in the open state, the folding part 142 rotates to separate from the tab 31; in the pressed state, the folding part 142 rotates to cover and press against the tab 31 to fix the tab 31 and connect to the pole post 16.
[0038] In this embodiment, the insulating layer 18 is specifically a lower plastic layer. This lower plastic layer is tightly disposed on the side of the cover plate body 11 facing the inside of the battery cell. Its function is to achieve reliable electrical isolation between the charged components such as the electrode post 16 and connecting piece 17 and the aluminum cover plate body 11, preventing internal short circuits. Furthermore, the lower plastic layer also serves as the basic mounting platform for the entire protective structure 14. The fixing part 141 is specifically a mounting base fixed to the lower plastic layer. This mounting base has two spaced-apart connecting arms, thus forming a receiving space between them. A pivot is provided on the inner side of each connecting arm. The two connecting arms provide stable double-sided support. The folding part 142 is specifically a protective plate. Shaft holes or bearing structures are correspondingly provided on the outer sides of both ends of this protective plate. By fitting the shaft holes at both ends of the protective plate onto the pivots of the two connecting arms, the protective plate can rotate around the pivot axis, thereby switching between the open and closed states.
[0039] During the cell assembly and welding stage, the operator first rotates the folding part 142 upwards to open it. At this time, a wide angle is formed between the folding part 142 and the fixing part 141 (generally, the folding part 142 is perpendicular to the cover plate body 11). The tab 31 at the top of the electrode group 3 is guided to the welding position below the pole post 16. Since the folding part 142 is fully open, welding tools (such as laser welding heads) can approach without obstruction and perform precise welding at the connection between the tab 31 and the pole post 16, ensuring a smooth welding process and reliable weld quality.
[0040] After welding is completed, the operator rotates the folding part 142 downwards, switching it from the open state to the pressed state. In this state, the folding part 142 rotates to a horizontal position, acting like a protective cover over the bent portion of the tab 31 and the weld mark formed between it and the pole post 16. The folding part 142 applies a controllable downward clamping force to the tab 31, which firmly presses the tab 31 onto the end face of the pole post 16.
[0041] In some embodiments, such as Figures 2 to 6As shown, the cell cover plate 1 also includes a connecting piece 17. The connecting piece 17 is disposed on the side of the cover plate body 11 away from the reference surface 111. One end of the connecting piece 17 is connected to the second end of the electrode post 16, and the other end of the connecting piece 17 extends to connect with the electrode tab 31.
[0042] In this embodiment, the connecting piece 17 is made of a highly conductive metal material, such as nickel or a nickel composite material. The function of the connecting piece 17 is to efficiently conduct current from the electrode group 3 inside the cell to the external electrode post 16 via the tab 31.
[0043] During cell assembly, the tab 31 at the top of the electrode assembly 3 is guided and placed on the welding area of the extension end of the connecting piece 17. Subsequently, the tab 31 and the connecting piece 17 are firmly fused together through processes such as laser welding. After welding is completed, the folding part 142 can be rotated downwards to switch it from an open state to a pressed state. In this state, the folding part 142 rotates to a horizontal position, covering the bent portion of the tab 31 and the weld mark formed with the connecting piece 17, thus pressing the tab 31 onto the connecting piece 17.
[0044] In some embodiments, such as Figures 3 to 6 As shown, the distance between the fixing part 141 and the insulating layer 18 along the height direction of the cover plate body 11 is H1, 0.5mm≤H1≤1mm; Specifically, maintaining a certain distance ensures that the fixing part 141 will not directly press or rub against the electrode group 3 under normal cell conditions, thereby avoiding damage that may be caused by contact. When H1 < 0.5mm, the small height of the fixing part 141 is not conducive to the rotation of the flipping part.
[0045] Furthermore, when the folding part 142 rotates to the horizontal pressing position, the clearance distance between its lower surface and the upper surface of the connecting piece 17 determines the degree of compression applied by the folding part 142 to the tab 31 clamped below it.
[0046] If the gap is too large (i.e., H2-t1-t2>0.5mm), the folding part 142 will not be able to apply effective pressure to the tab 31, and the tab 31 may still loosen under vibration, resulting in poor fixation. Conversely, if the gap is too small (i.e., H2-t1-t2<0.2mm), the pressure of the folding part 142 on the tab 31 and solder joint will be too great, posing a risk of damaging the metal foil of the tab 31 or the solder joint, which will also affect the reliability and safety of the battery cell. Therefore, controlling the clamping gap within the range of 0.2 mm to 0.5 mm ensures that the folding part 142 can fully fix the tab 31 without the risk of damage.
[0047] In some embodiments, such as Figures 3 to 6As shown, the distance between the fixing part 141 and the connecting piece 17 along the length of the cover plate body 11 is A, where 1mm ≤ A ≤ 3mm. This distance defines the horizontal safety distance between the inner edge of the fixing part 141 and the edge of the connecting piece 17.
[0048] When the value of A is not less than 1 mm, it can effectively prevent the fixing part 141 from contacting or interfering with the connecting piece 17 due to manufacturing or assembly tolerances, ensuring smooth assembly. At the same time, when the value of A is not greater than 3 mm, it can ensure that the fixing part 141 is sufficiently close to the connecting piece 17 and the edge of the electrode group 3 below it in the horizontal direction. This design allows the fixing part 141 to effectively block and limit the horizontal movement of the electrode group 3 when the cell is subjected to severe lateral impact. Together with the vertical gap H1, it forms a three-dimensional constraint on the movement of the electrode group 3, preventing the electrode group 3 from excessively displacing and pulling the electrode tab 31.
[0049] The connecting piece 17 includes a first part and a second part that are interconnected. The first part and the second part are generally positioned at different heights. The first part is connected to the second end of the pole post 16, and the second part is connected to the pole lug 31. When the protective structure 14 is in a pressed state, the distance B between the folded part 142 and the first part along the length of the cover plate body 11 is 2mm ≤ B ≤ 5mm. This distance determines the amount of coverage extension of the inner edge of the folded part 142 relative to the edge of the connecting piece 17 in the pressed state. When the value of B is within the range of 2mm to 5mm, it can be ensured that after the folded part 142 is pressed, its inner edge is sufficient to completely cover the welding area (i.e., weld mark) between the pole lug 31 and the connecting piece 17, preventing any part of the weld mark from being exposed, thereby providing reliable physical isolation and protection. Sufficient coverage (B≥2mm) is the lower limit to ensure the protective effect, while a reasonable upper limit (B≤5mm) avoids the folded part 142 from extending too far inward, which may interfere with other structures on the top of the pole group 3 or unnecessarily increase the size and weight of the protective structure 14.
[0050] In some embodiments, such as Figures 5 to 6 As shown, the connecting piece 17 is provided with two electrode welding stations 171 arranged along the width direction of the cover plate body 11. The distance between the outermost two electrode welding stations 171 along the width direction of the cover plate body 11 is W0, and the width of the folded part 142 along the width direction of the cover plate body 11 is W1, 2mm≤(W1-W0) / 2≤3.5mm.
[0051] In this embodiment, the actual physical meaning of (W1-W0) / 2 is the amount by which each edge of the folded portion 142 extends beyond the outermost edge of the tab welding station 171 in the width direction, i.e., the single-sided coverage allowance.
[0052] When the single-sided coverage allowance is not less than 2 mm, it can be fully guaranteed that the folded part 142 can completely cover the entire welding area of the tab 31 in the width direction. This provides sufficient design margin for possible minor alignment errors during the welding process and for the certain width tolerance of the tab 31 itself, effectively avoiding the problem of exposed welding edge due to dimensional fluctuations.
[0053] Setting the upper limit of the single-sided coverage margin to 3.5 mm prevents the fold section 142 from being designed too wide. An excessively wide fold section 142 would not only occupy space inside the cell and affect energy density, but more importantly, it could become a new stress concentration point under long-term vibration, which would be detrimental to the long-term stability of the overall structure.
[0054] In some embodiments, the mounting boss 113 is provided with a mounting groove, and the battery cell cover plate 1 further includes: an explosion-proof valve 15, which is disposed in the mounting groove; the mounting boss 113 is provided with at least one venting notch communicating with the mounting groove.
[0055] In this embodiment, when thermal runaway occurs in the battery cell, the high-temperature gas inside can be discharged through the explosion-proof valve 15. The high-temperature and high-pressure gas flow can quickly escape from the area of the mounting boss 113 through the exhaust port. This provides an efficient and smooth discharge channel for the high-temperature expanding gas, effectively avoiding the problem of gas accumulating around the explosion-proof valve 15 or disorderly impacting other components.
[0056] like Figure 1 As shown, 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; In this embodiment, 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 respectively and continuously disposed on the two outer edges of the aforementioned boss array along the width direction of the cover plate body 11.
[0057] 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.
[0058] The second reinforcing rib 13 is disposed around the periphery of the mounting boss 113 corresponding to the explosion-proof valve 15. 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 15. Its function is to provide localized reinforcement to the mounting area of the explosion-proof valve 15 from the side. The second reinforcing rib 13 can provide effective support and protection for the explosion-proof valve 15 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 welding sealing and operational accuracy of the explosion-proof valve 15, thereby ensuring that the explosion-proof valve 15 is reliably triggered under predetermined operating conditions.
[0059] To further optimize the pressure relief function, a dedicated exhaust channel is designed into the structure. Specifically, a first exhaust notch 121 is stamped or machined on the first reinforcing rib 12, and correspondingly, there is no second exhaust notch 131 on the second reinforcing rib 13 at the position corresponding to the first exhaust notch 121. The first exhaust notch 121 and the second exhaust notch 131 are aligned in the horizontal direction, forming a gas venting channel. When thermal runaway occurs in the battery cell, the high-temperature gas inside can be discharged from the explosion-proof valve 15. The high-temperature and high-pressure gas flow can first escape rapidly from the mounting boss 113 area through the second exhaust notch 131, and then be guided to the edge through the first exhaust notch 121.
[0060] In some embodiments, such as Figures 1 to 4 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 along the height direction of the cover plate body 11 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.
[0061] 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 15, as well as the reference surface 111 area where the pole post 16 is welded, thus protecting critical safety components.
[0062] 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.
[0063] like Figure 7 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.
[0064] 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 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.
[0065] In one specific embodiment, as shown in Table 1 below, the distance between the fixing part and the insulating layer along the height direction of the cover plate body is H1, and the distance between the rotation position of the folding part and the pole along the height direction of the cover plate body is H2. The total wall thickness of the folding part is t, the wall thickness of the folding part is t1, and the wall thickness of the connecting piece is t2.
[0066] The distance between the fixing part and the connecting piece along the length of the cover plate body is A. The distance between the folding part and the connecting piece along the length of the cover plate body is B. The distance between the outermost edges of the two electrode lug welding stations is W0, and the width of the folding part along the width of the cover plate body is W1.
[0067] The key parameters of all embodiments fall within the preferred range claimed by this invention (0.5mm≤H1≤1mm, 0.2mm≤H2-t1-t2≤0.5mm, 2mm≤(W1-W0) / 2≤3.5mm). The test results show a high degree of consistency. CT scans confirmed that, under various parameter combinations, the folded portion of the protective plate could completely cover the electrode tab solder marks without any exposed parts, thus meeting the basic requirements for physical protection.
[0068] After rigorous testing, disassembly of the battery cells revealed no obvious signs of axial or lateral movement in the internal electrode groups. This indicates that the fixing part achieves effective non-contact limiting through distance H1, while the folding part provides stable clamping force through precise clamping gaps (H2-t1-t2) and coverage width ((W1-W0) / 2), jointly ensuring the positional stability of the electrode groups and electrode tabs under harsh operating conditions.
[0069] In summary, the above two points demonstrate that within the parameter range of this invention, the internal connection reliability of the battery cell is high and the safety performance is significantly improved.
[0070] The comparative test results, from the opposite perspective, verified the criticality and necessity of the parameter range of the present invention.
[0071] Comparative Example 1 shows that when the clamping gap (H2-t1-t2) is below the lower limit (0.2mm), the protection mechanism will turn into a damage mechanism.
[0072] Comparative Example 2 shows that the protective function fails when the clamping gap (H2-t1-t2) exceeds the upper limit (0.5mm).
[0073] Comparative Example 3 shows that when the coverage width ((W1-W0) / 2) is below the lower limit (2mm), the tolerance for manufacturing and assembly tolerances cannot be guaranteed, and the protection is unreliable.
[0074] Through comparative tests of the embodiments and comparative examples, it can be clearly concluded that the parameter range regarding the critical dimensions between the protective structure and the electrode assembly and tabs claimed in this invention is the optimal choice after thorough verification. Within this range, the protective structure can provide optimal fixation and protection without damaging the electrode assembly and tabs, significantly improving the mechanical safety and reliability of the battery cell. Any design exceeding this range may result in insufficient protection or introduce new risks of damage.
[0075] Table 1 H1 (mm) H2 (mm) t (mm) t1 (mm) t2 (mm) A (mm) B (mm) W1 (mm) W0 (mm) H2-t1-t2 (mm) (W1-W0) / 2 (mm) Example 1 0.5 1 0.7 0.3 0.5 1 2 9 4.5 0.2 2.25 Example 2 0.55 1.1 0.75 0.35 0.45 1.2 2.5 9 4.8 0.3 2.10 Example 3 0.6 1.3 0.8 0.4 0.42 1.5 3 9 5 0.5 2.00 Example 4 0.63 1.1 0.65 0.25 0.38 1.8 3.6 10 5.3 0.5 2.35 Example 5 0.65 1.15 0.7 0.28 0.52 2 4 11 5.5 0.4 2.75 Example 6 0.7 1 0.7 0.32 0.48 2.2 4.3 10.5 5.8 0.2 2.35 Example 7 0.75 1.2 0.8 0.38 0.45 2.5 5 10.8 6 0.4 2.40 Example 8 0.85 1.1 0.75 0.35 0.47 2.7 4.6 12 6.2 0.3 2.90 Example 9 0.9 1.1 0.7 0.3 0.43 3 3.8 12.5 5.9 0.4 3.30 Comparative Example 1 0.5 0.9 0.7 0.3 0.5 1 2 9 4.5 0.1 2.25 Comparative Example 2 0.6 1.4 0.8 0.4 0.42 1.5 3 9 5 0.6 2.00 Comparative Example 3 0.6 1.3 0.8 0.4 0.42 1.5 3 8.7 5 0.5 1.85 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 is used to connect with the electrode tab. The protective structure is rotatably connected to the side of the cover plate body opposite to the reference surface, and has an open state and a closed state. In the open state, the protective structure is separated from the tab; in the pressed state, the protective structure covers and presses against the tab to fix the tab and connect to the second end of the pole post.
2. The cell cover plate according to claim 1, characterized in that, The cell cover plate further includes: an insulating layer disposed on the side of the cover plate body opposite to the reference surface; The protective structure includes: a fixing part and a folding part; The fixing part is disposed on the side of the insulating layer opposite to the cover plate body; the folding part is rotatably connected to the fixing part; In the open state, the folded portion is separated from the tab; in the pressed state, the folded portion covers and presses against the tab to fix the tab and connect to the pole post.
3. The cell cover plate according to claim 2, characterized in that, The cell cover plate further includes a connecting piece disposed on the side of the cover plate body away from the reference surface, one end of the connecting piece being connected to the second end of the electrode post, and the other end of the connecting piece extending to be connected to the electrode tab.
4. The cell cover plate according to claim 3, characterized in that, The distance between the fixing part and the insulating layer along the height direction of the cover plate body is H1, where 0.5mm≤H1≤1mm; In the pressed state, the distance between the rotating position of the folded part and the pole post along the height direction of the cover plate body is H2, the wall thickness of the folded part is t1, the wall thickness of the connecting piece is t2, and 0.2mm≤H2-t1-t2≤0.5mm.
5. The cell cover plate according to claim 3, characterized in that, The distance between the fixing part and the connecting piece along the length of the cover plate body is A, where 1mm≤A≤3mm; The connecting piece includes: a first part and a second part that are connected to each other, the first part being connected to the second end of the pole post, and the second part being connected to the pole tab; When the protective structure is in a pressed state, the distance between the folded part and the first part along the length direction of the cover plate body is B, where 2mm≤B≤5mm.
6. The cell cover plate according to claim 3, characterized in that, The connecting piece is provided with two electrode welding stations arranged along the width direction of the cover plate body; the distance between the outermost two electrode welding stations along the width direction of the cover plate body is W0, and the width of the folded part along the width direction of the cover plate body is W1, 2mm≤(W1-W0) / 2≤3.5mm.
7. 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 at least one venting notch that communicates with the mounting groove.
8. The cell cover plate according to claim 7, 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.
9. The cell cover plate according to any one of claims 1-8, characterized in that, The support boss is provided in two parts, and the two support bosses are located at both ends of the mounting boss along the length direction of the cover plate body; The support boss is provided with an adhesive application area; The cell cover plate further includes: structural adhesive, disposed in the adhesive application area; along the height direction of the cover plate body, the height of the structural adhesive relative to the reference surface is greater than the height of the mounting boss relative to the reference surface, so as to abut against the external structure through the structural adhesive.
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.