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, the reference surface is provided with a plurality of support bosses arranged along the length direction of the cover plate body, and each support boss is convexly arranged on the reference surface; the pole penetrates through the pole hole; the height of the supporting boss relative to the reference surface is greater than that of the pole protruding out of the reference surface; the projection area of the cover plate body on the plane where the datum plane is located is S1, the sum of the projection areas of all the supporting bosses is S2, the projection area of the pole hole allowing the pole to penetrate through is S3, and the conditions that 0.25 < = S2 / S1 < = 0.35 and 0.015 < = S3 / S1 < = 0.03 are met. According to the battery cell cover plate, the effective heat dissipation area is increased by arranging the multiple supporting platforms, meanwhile, possible deformation, damage or internal connection failure caused by direct stress of the pole columns are effectively avoided, and the short circuit risk caused by damage of the pole columns is fundamentally 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, with their advantages of high energy density and long cycle life, have become the core power source for electric vehicles, energy storage systems, and other fields. As the basic unit of a lithium-ion battery, the structural design of the cell directly affects the overall performance, safety, and energy density of the battery pack.

[0003] Traditional battery cell covers are typically flat metal plates with protruding terminals. Inside the battery pack, these terminals are electrically connected and fixed to the upper casing via busbars. However, a large portion of the cover body has a gap with the upper casing, preventing direct contact. This structure has significant drawbacks. First, it has poor mechanical strength. When the battery pack is impacted, the force is concentrated on the protruding terminals, leaving the cover body without load-bearing capacity, which can easily lead to damage or short circuits in the terminals. Second, it has a single heat dissipation path. Heat is primarily conducted through the terminals, while the cell cover can only dissipate heat through inefficient thermal radiation, which can easily cause abnormal cell temperatures. Summary of the Invention

[0004] This invention provides a cell cover plate and a cell to solve the problems of cell terminals being easily subjected to external forces and poor heat dissipation of cell cover plates.

[0005] This invention provides a battery cell cover plate, comprising: The cover plate body has a reference surface on one side, and a plurality of support protrusions are formed on the reference surface along the length direction of the cover plate body. Each support protrusion protrudes from the reference surface, and a pole hole is formed between at least two adjacent support protrusions. A pole post, passing through the pole post hole, is located between two adjacent support bosses therein, with one end of the pole post 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 post protruding from the reference surface; Wherein, on the projection plane perpendicular to the reference plane, the projected area of ​​the cover plate body on the plane where the reference plane is located is S1, the sum of the projected areas of all the supporting bosses is S2, and the projected area of ​​the pole hole through which the pole passes is S3, satisfying: 0.25≤S2 / S1≤0.35, 0.015≤S3 / S1≤0.03.

[0006] According to the present invention, a battery cell cover plate is provided, wherein three supporting bosses are provided and arranged along the length direction of the cover plate body at both ends and the middle of the reference surface; two pole posts are provided, and the two pole posts respectively penetrate the corresponding pole post holes.

[0007] According to a battery cell cover provided by the present invention, the distance between the electrode post and the adjacent support boss in the length direction of the cover body is A, which satisfies A≥4mm.

[0008] According to the present invention, in the height direction of the cover body, the supporting boss protrudes from the reference surface by a distance H1, the first end of the electrode protrudes from the reference surface by a distance H0, and the supporting boss is higher than the first end of the electrode by a distance H2, satisfying 1.5mm≤H2=(H1-H0)≤3mm.

[0009] According to the present invention, the length of the cover body in the width direction of the cover body is W1, and the length of a single support boss in the width direction of the cover body is W2, satisfying: 6mm≤(W1-W2)≤16mm.

[0010] According to the present invention, the thickness of the cover body is T1, which satisfies 2.0mm≤T1≤2.5mm.

[0011] According to a battery cell cover plate provided by the present invention, the supporting boss is a conical boss, the conical boss includes a top wall and an inclined side wall surrounding the top wall and connected to the reference surface; The thickness of the cover plate body at the edge of the pole hole is T2, the thickness of the inclined sidewall is T3, and the thickness of the top wall is T4, satisfying the following relationships: 0.7≤T2 / T1≤0.8, 0.7≤T3 / T1≤0.85, 0.7≤T4 / T1≤0.9.

[0012] According to a battery cell cover plate provided by the present invention, the supporting boss has a cavity formed on the side opposite to the reference surface; The cell cover plate also includes: An insulating component is disposed on the side of the cover plate body opposite to the reference surface. The insulating component has a groove formed at the position of the cavity. The groove is disposed in the cavity. The gap between the side wall of the groove and the side wall of the cavity is B, which satisfies B≥1mm.

[0013] A battery cell provided by the present invention comprises: The battery cell casing has an opening at the first end and an explosion-proof valve at the second end. The aforementioned cell cover plate has a cover plate body disposed at the opening and forming a receiving cavity with the cell housing; the first end of the electrode post protrudes from the side of the cover plate body away from the cell housing, and the second end of the electrode post extends into the receiving cavity; An electrode assembly is disposed within the receiving cavity, and the electrode tabs of the electrode assembly are connected to the second end of the electrode post.

[0014] According to a battery cell provided by the present invention, a reinforcing rib is provided on the second end surface of the battery cell housing, and the reinforcing rib is disposed around the explosion-proof valve.

[0015] The cell cover plate provided in this embodiment, when integrating the cell into the battery module or battery pack, ensures that the top surface of the supporting boss contacts the inner wall of the upper casing before the terminal post, thus becoming the main load-bearing and support structure. When the battery pack is subjected to external impact or vibration, the impact force acts directly and over a large area through the upper casing onto multiple supporting bosses, rather than being concentrated on the terminal post alone. This effectively avoids deformation, damage, or internal connection failure that may occur to the terminal post due to direct force, fundamentally reducing the risk of short circuits caused by terminal post damage.

[0016] Meanwhile, the multiple support bosses transform the contact between the cover plate and the upper battery pack housing from a traditional point contact to a multi-point surface contact. The support bosses provide additional heat conduction channels. Heat can be conducted from inside the battery cell through the cover plate to the support bosses, and then rapidly dissipated through the direct contact between the support bosses and the upper housing, significantly increasing the effective heat dissipation area.

[0017] In addition, by adjusting the parameter settings on the cell cover, it is ensured that the support boss has a sufficient overall projected area to provide effective support and heat dissipation, while the limitation of the pole hole area ensures the strength of the pole mounting area. Attached Figure Description

[0018] 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.

[0019] Figure 1 This is a three-dimensional structural diagram of the battery cell cover plate provided by the present invention.

[0020] Figure 2 This is a schematic diagram of the front of the battery cell cover plate provided by the present invention.

[0021] Figure 3 yes Figure 2 A schematic diagram of the cross-section at position AA.

[0022] Figure 4 This is a partial cross-sectional schematic diagram of the battery cell cover plate provided by the present invention.

[0023] Figure 5 This is a schematic diagram of the back side of the battery cell cover provided by the present invention.

[0024] Figure 6 This is a schematic diagram of the battery cell provided by the present invention.

[0025] Figure 7 This is a schematic diagram of the bottom of the battery cell provided by the present invention.

[0026] Figure label: 1. Cell cover plate; 11. Cover plate body; 111. Reference surface; 112. Support boss; 12. Reinforcing rib; 13. Protective component; 14. Explosion-proof valve; 15. Terminal post; 151. Connecting part; 16. Insulating component; 161. Groove; 2. Cell casing; 3. Electrode assembly; 31. Electrode tab. Detailed Implementation

[0027] 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.

[0028] 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.

[0029] The following is combined Figures 1-7 The present invention describes the cell cover plate 1 and the cell provided by the present invention.

[0030] In some embodiments, such as Figure 1 and Figure 2 As shown, the cell cover 1 includes: a cover body 11 and a terminal post 15.

[0031] In this embodiment, the cover plate body 11 is typically made of stamped metal sheet, and a reference surface 111 is formed on its upper surface. For example... Figure 1As shown, the X-axis represents the length of the cover plate body 11, the Y-axis represents the width of the cover plate body 11, and the Z-axis represents the height of the cover plate body 11. Multiple support bosses 112 are integrally formed on the reference surface 111 using a stamping process. These support bosses 112 are spaced apart along the length (X-axis) of the cover plate body 11. In this embodiment, three support bosses 112 are preferably provided. Each support boss 112 protrudes upward from the reference surface 111. In the area between at least two adjacent support bosses 112, pole posts are machined into the cover plate body 11. Poles 15 penetrate the pole post holes and are fixedly connected to the cover plate body 11 and electrically insulated and sealed by riveting, welding, or integral forming. The pole post 15 is located between two adjacent support bosses 112, with one end protruding from the reference surface 111. In the direction perpendicular to the reference plane 111, the protrusion height of the top of each support boss 112 relative to the reference plane 111 is greater than the height of the outer end of the terminal post 15 protruding from the reference plane 111. The top surface of the support boss 112 will contact the upper casing or module end plate of the battery pack before the terminal post 15, thereby making the support boss 112 the main mechanical load-bearing and force transmission component, effectively protecting the terminal post 15 from direct impact.

[0032] like Figure 1 and Figure 2 As shown, projection is defined in a direction perpendicular to the reference plane 111.

[0033] S1 is the projected area of ​​the cover plate body 11 on the plane where the reference plane 111 is located. It can be understood as the area of ​​the contour region obtained by projecting the cover plate structure with the supporting boss 112 and the pole hole vertically back to its original reference plane along the height direction. S1 essentially represents the overall contour area of ​​the cover plate body 11, and is the maximum planar projected size of the cover plate body 11.

[0034] S2 is the sum of the projected areas of all the support bosses 112 on the reference plane 111. That is, the sum of the projected areas of the top contour (or the top main load-bearing surface) of each support boss 112 on the reference plane 111. S2 directly reflects the theoretical maximum contact area between the support boss 112 and the battery pack housing or module structure, and is a parameter that affects the mechanical support force and heat conduction area.

[0035] S3 is the projected area of ​​the electrode post hole through which the electrode post 15 passes on the reference plane 111. This typically corresponds to the opening area of ​​the electrode post hole itself. S3 relates to the cross-sectional area of ​​the electrode post 15, thus affecting the current carrying capacity. It also reflects the amount of material removed from the cover plate body 11 due to the opening, directly affecting the local structural strength of this area.

[0036] Through in-depth research and experimental verification, this invention has determined that the above three area parameters must satisfy the following mathematical relationships: 0.25≤S2 / S1≤0.35, 0.015≤S3 / S1≤0.03.

[0037] Regarding the ratio of S2 / S1: This ratio ensures that the total projected area of ​​the supporting boss 112 accounts for the proportion of the projected area of ​​the cover plate body 11.

[0038] If S2 / S1<0.25, the total area of ​​the support boss 112 is too small, which may result in insufficient overall support stiffness, making it unable to effectively distribute the load from the upper housing and thus failing to adequately protect the pole post 15 and ensure uniform force distribution.

[0039] If S2 / S1>0.35, the total area of ​​the bosses is too large. On the one hand, this may cause difficulties in material flow during stamping, increase the risk of cracking, and reduce production yield. On the other hand, an overly dense boss layout may compress the necessary electrical safety distance around the pole post 15 or occupy too much space inside the cell, which is not conducive to the layout of other components.

[0040] Within the range of 0.25≤S2 / S1≤0.35, the supporting boss 112 provides sufficient direct thermal contact area. Heat can be efficiently conducted from the cover body 11 to the upper housing through this part, significantly improving the bottleneck of traditional cover plates that rely solely on the pole post 15 for heat conduction, and enhancing the overall heat dissipation efficiency.

[0041] Regarding the S3 / S1 ratio: The S3 / S1 ratio is directly related to the cross-sectional area of ​​pole 15.

[0042] If S3 / S1 < 0.015, the electrode hole is too small, which may result in insufficient cross-sectional area of ​​electrode 15, affecting the high current carrying capacity and increasing resistance and heat generation.

[0043] If S3 / S1 > 0.03, the pole hole is too large. Although this may be beneficial to electrical performance, it will create an excessively large material defect area on the cover plate body 11, severely weakening the structural integrity at that location. Under external impact or internal pressure, the excessively large hole edge area is prone to become a stress concentration point and failure starting point, leading to cover plate deformation or sealing failure.

[0044] In this embodiment, the cell cover plate 1, when integrating the cell into the battery module or battery pack, ensures that the top surface of the supporting boss 112 contacts the inner wall of the upper casing before the terminal post 15, thus becoming the main load-bearing and support structure. When the battery pack is subjected to external impact or vibration, the impact force acts directly and over a large area through the upper casing onto multiple supporting bosses 112, rather than being concentrated on the terminal post 15 alone. This effectively avoids deformation, damage, or internal connection failure that may occur to the terminal post 15 due to direct force, fundamentally reducing the risk of short circuits caused by damage to the terminal post 15.

[0045] Meanwhile, the arrangement of multiple support bosses 112 transforms the contact between the cover plate body 11 and the upper casing of the battery pack from a traditional point contact to a multi-point surface contact. The support bosses 112 provide additional heat conduction channels. Heat can be conducted from inside the battery cell through the cover plate body 11 to the support bosses 112, and then rapidly dissipated through the direct contact between the support bosses 112 and the upper casing, significantly increasing the effective heat dissipation area.

[0046] In addition, by adjusting the parameter settings on the cell cover plate 1, it is ensured that the support boss 112 has a sufficient overall projected area to provide effective support and heat dissipation, while the limitation of the pole hole area ensures the strength of the pole 15 mounting area.

[0047] In some embodiments, such as Figure 1 and Figure 2 As shown, there are three support bosses 112. These three support bosses 112 are not randomly arranged, but are arranged at both ends and the middle of the reference surface 111 along the length of the cover plate body 11.

[0048] Specifically, one support boss 112 is located at the first end of the cover plate body 11 in the length direction, another is located at the second end opposite it, and a third is located at the center of these two ends. This "two ends plus the middle" layout constitutes a stable three-point or multi-point support.

[0049] When the cell cover 1 is installed inside the battery pack, the three support protrusions 112 contact the inner wall of the battery pack's upper casing, enabling them to uniformly and stably withstand mechanical loads and impacts from all directions. This effectively prevents cover warping or localized stress concentration, significantly improving the rigidity and vibration and impact resistance of the entire battery module. Simultaneously, these three support protrusions 112 also form three main heat conduction paths, efficiently guiding the heat from the cover body 11 to the casing, thus optimizing heat dissipation uniformity.

[0050] Corresponding to the output requirements of the positive and negative tabs 31 inside the battery cell, two terminals 15 are provided. These two terminals 15 are used to connect the positive and negative terminals of the battery cell, respectively. Each terminal 15 independently passes through a corresponding terminal hole. These two terminal holes, and thus the two terminals 15 themselves, are respectively located in the interval area between the support boss 112 located in the middle and the support boss 112 located at one of the ends. In other words, the two terminals 15 are not concentrated in one place, but are spaced apart in the length direction by at least one support boss 112 (usually the middle boss). This arrangement electrically ensures sufficient creepage distance and clearance between the positive and negative terminals 15, improving safety and insulation reliability. Moreover, it functionally separates and coordinates the electrical connection point (terminal 15) and the mechanical load-bearing point (support boss 112) in space. In addition, this arrangement helps to quickly dissipate the heat generated during charging and discharging through the adjacent support boss 112, avoiding local heat accumulation.

[0051] like Figure 2 As shown, in the length direction of the cover plate body 11, the distance between the pole post 15 and the adjacent support boss 112 is A, which satisfies A≥4mm.

[0052] In this embodiment, the terminal post 15 is a live component, while the supporting boss 112 is typically integrated with the cover plate body 11. Maintaining a gap of at least 4 mm is primarily to ensure sufficient air gap and creepage distance between the two. This effectively prevents electrical breakdown or surface leakage between the terminal post 15 and the boss under harsh operating conditions such as high temperature, high humidity, or the presence of contaminants, fundamentally eliminating the risk of short circuits and meeting the extreme electrical safety requirements of high-voltage platform power batteries.

[0053] When the battery pack is subjected to strong impact or vibration, the support boss 112, as the main load-bearing point, will undergo slight deformation or displacement. The design with a spacing A ≥ 4mm effectively creates a buffer zone between the terminal post 15 and the boss. This space can absorb and accommodate the slight deformation that the boss may undergo under stress, preventing the boss from directly colliding with or squeezing the terminal post 15 due to excessive deformation. This protects the terminal post 15 and its sealing structure with the cover from indirect mechanical stress, maintaining the integrity of the terminal post 15 connection and the reliability of the seal.

[0054] Furthermore, this spacing prevents excessive heat concentration in certain areas due to the pole post 15 and the support protrusion 112 being too close, and also prevents reduced heat conduction efficiency due to excessive distance. A distance of 4mm or more, combined with the metal substrate of the cover plate body 11, allows heat to be more rationally and evenly diffused from the pole post 15 area to the entire cover plate and each support protrusion 112 before being discharged, which helps to improve the overall thermal balance.

[0055] In some embodiments, such as Figures 1 to 4 As shown, in the height direction of the cover plate body 11, the support boss 112 protrudes from the reference surface 111 by a distance of H1, the first end of the pole post 15 protrudes from the reference surface 111 by a distance of H0, and the support boss 112 is higher than the first end of the pole post 15 by a distance of H2, satisfying 1.5mm≤H2=(H1-H0)≤3mm.

[0056] Specifically, H2 is limited to 1.5mm or more, meaning the top surface of the support boss 112 protrudes sufficiently relative to the end face of the terminal post 15. When the cell is integrated into the battery module or PACK housing, the inner wall of the housing or related structural components will first and stably contact the top surface of the higher support boss 112, thus making the support boss 112 the part that bears the pressure, vibration, and external impact of the housing. The terminal post 15, because its end face is relatively concave, does not make direct hard contact with the housing under normal assembly conditions, thus being effectively protected. This achieves the design objective of "boss bearing the force, terminal post 15 protected from disaster," greatly reducing the risk of short circuits caused by deformation, sealing failure, or internal connection breakage due to direct force on the terminal post 15.

[0057] Meanwhile, the height H2 of the support boss above the first end of the pole post 15 also provides installation space for the welding and connection of the busbar. After the busbar is welded to the end face of the pole post 15, its thickness will occupy some space. H2 ≥ 1.5mm ensures that even if the busbar is welded on, the support boss 112 can still be higher than or at least flush with the upper surface of the busbar, maintaining its main supporting position. The upper limit of H2 is set to about 3.0mm. An excessively large H2 would require the support boss 112 to be stamped deeper, which would exacerbate the thinning effect of the material during the stamping process and affect the strength of the cover plate body 11.

[0058] In some embodiments, such as Figure 1 and Figure 2 As shown, the length of the cover plate body 11 in its width direction is W1, and the length of a single support boss 112 in the width direction of the cover plate body 11 is W2, satisfying: 6mm≤(W1-W2)≤16mm.

[0059] In this embodiment, the side of the cover plate body 11 needs to be sealed to the metal shell of the battery cell through laser welding. The difference (W1-W2) corresponds to the width between the edge of the support boss 112 and the side of the cover plate body 11. If (W1-W2) < 6mm, the welding flange of the cover plate body 11 is too narrow, which may lead to insufficient absolute width of the weld and a decrease in long-term sealing reliability. Sufficient width on both sides of the cover plate body 11 (at least 3mm on each side) prevents the cover plate edge from curling or becoming unstable, and maintains the structural integrity of the cover plate body 11 and the battery cell shell 2. The edge area of ​​the cover plate body 11 is not only a structural component, but also a heat dissipation surface. This part of the metal area can conduct and radiate the heat generated inside the battery cell laterally. A moderately wide edge width provides additional and effective heat dissipation area, which helps to reduce the temperature gradient in the width direction of the cover plate, prevents excessive heat concentration on the support boss 112, and promotes a more uniform temperature distribution inside the battery cell. At the same time, (W1-W2) ≤ 16mm ensures that the width W2 of the support boss 112 is not too small. The support boss 112 needs to have sufficient width (W2) to provide an effective support plane and heat conduction area. If the support boss 112 is too narrow, its support stability and heat dissipation efficiency will decrease.

[0060] In some embodiments, such as Figure 3 As shown, the thickness of the cover plate body 11 is T1, satisfying 2.0mm ≤ T1 ≤ 2.5mm. T1 ≥ 2.0mm ensures that the cover plate body 11 has sufficient basic rigidity and strength. This thickness can effectively resist overall bending deformation when the battery pack is subjected to vibration, impact, or internal pressure. Simultaneously, the value of T1 directly determines the feasibility of the stamping process and the forming quality. A thickness T1 within the range of 2.0mm to 2.5mm gives the cover plate body 11 good stamping formability. T1 ≥ 2.0mm ensures that the cover plate body 11 has sufficient material in the height direction to establish an efficient heat conduction path, allowing heat to be quickly transferred from the inside of the cell to the surface. Furthermore, while an excessively thick cover plate body 11 can reduce thermal resistance, the resulting increase in weight and material cost is no longer economical compared to the improved heat dissipation benefits, and it would also reduce the mass energy density of the battery system. Therefore, the thickness generally needs to be less than 2.5mm.

[0061] like Figures 1 to 4 As shown, the support boss 112 is a conical boss, which includes a top wall and an inclined side wall surrounding the top wall and connected to the reference surface 111; the thickness of the cover plate body 11 at the edge of the pole hole is T2, the thickness of the inclined side wall is T3, and the thickness of the top wall is T4, satisfying the following relationships: 0.7≤T2 / T1≤0.8, 0.7≤T3 / T1≤0.85, 0.7≤T4 / T1≤0.9.

[0062] In this embodiment, T2 refers to the thickness of the cover plate body 11 at the edge of the electrode hole. This is the location where the electrode 15 passes through and is sealed. T3 refers to the thickness of the inclined sidewall of the conical boss. Due to material stretching during the stamping process, the thickness here is usually reduced from the original material thickness, and its uniformity and final value directly affect the boss's crush resistance and fatigue resistance. T4 refers to the thickness of the top wall of the conical boss. This is the main load-bearing surface supporting the contact between the boss 112 and the battery pack housing, and its thickness determines the stiffness and load-bearing capacity of this contact point.

[0063] The ratio of T2 to T1 is set between 0.7 and 0.8, which means that even after processing, the edge of the pole hole must retain 70% to 80% of the original substrate thickness. This ensures sufficient strength to withstand the installation stress of the pole 15, the clamping force of the sealing ring, and the load that may be generated by internal air pressure, preventing the periphery of the pole hole from cracking or deforming due to insufficient strength.

[0064] The T3 / T1 ratio should be limited to 0.7 to 0.85, which means the sidewall thickness reduction rate should be controlled within 15% to 30%. If the ratio is too low (T3 / T1<0.7), it is equivalent to excessive thinning of the conical boss, making the sidewall of the conical boss prone to cracking or severely weakening its strength; if the ratio is too high (T3 / T1>0.85), it will lead to insufficient material flow, affecting the boss height or shape accuracy.

[0065] As the direct load-bearing surface, the top wall has its thickness T4 to T1 ratio set to be no less than 0.7. This ensures that even after stamping, the top wall still maintains a considerable absolute thickness, thereby providing extremely high local bending stiffness and compressive strength. This avoids excessive elastic deformation or plastic indentation under the pressure of the box, ensuring the stability of the support.

[0066] In some embodiments, such as Figures 3 to 5 The supporting boss 112 has a cavity formed on the side away from the reference surface 111; the cell cover plate 1 also includes an insulating component 16, which is made of plastic and is injection molded from engineering plastics such as PP and PPS. It is disposed on the side of the cover plate body 11 away from the reference surface 111 and is fixedly connected to it. Its main function is to isolate the cover plate body 11 from the electrode group 3 to prevent short circuit.

[0067] To perfectly fit the new structure of the cover plate body 11, a groove 161 is integrally formed on the insulating member 16 at a position corresponding to the cavity of the supporting boss 112. In the assembled state, the groove 161 of the insulating member 16 is embedded (or accommodated) in the cavity of the cover plate, forming a nested fit, which can significantly reduce the overall base height of the insulating member 16, thereby compressing the space between the cell cover plate 1 and the electrode group 3.

[0068] The gap B between the sidewall of the groove 161 and the sidewall of the cavity satisfies B≥1mm. This 1mm gap ensures that even under the worst tolerance conditions, the groove 161 of the insulating component 16 will never experience hard interference or compression with the sidewall of the metal cavity, guaranteeing smooth assembly and high yield. Secondly, abnormal external forces (such as severe vibration) may cause micro-deformation of the cell cover plate 1 or its internal structure. This gap prevents abnormal stress between the insulating component 16 and the cover plate body 11 caused by minute deformation, preventing the insulating component 16 from being crushed and maintaining its insulation integrity.

[0069] like Figure 4 As shown, the taper of the cavity of the supporting boss 112 is β, and the taper of the groove 161 of the insulating member 16 is γ. The two are equal and satisfy 65 ≤ β = γ ≤ 75 degrees. 65° to 75° is a relatively large tilt angle. This angle is used for the bending and placement of the top tab 31 of the pole group 3. The near-vertical space formed by the large angle can provide a cavity for the stacked tabs 31 with considerable thickness extending from the pole group 3 or the protruding part after multiple tabs 31 converge.

[0070] During assembly, the concave cavity of the supporting boss 112 has the same taper as the groove 161 of the insulating component 16. Even with slight initial alignment deviations, this ensures that the insulating component 16 slides into the correct position, significantly improving assembly efficiency and consistency. After assembly, this structure effectively restricts any slight radial movement or rotation of the insulating component 16 relative to the cover plate, preventing it from loosening or shifting due to long-term vibration. Furthermore, the vertical inner wall of the groove 161 and the cavity (corresponding to a large angle β / γ) provides direct mechanical restraint and protection for the protruding portion at the apex of the electrode group 3 or the root of the tab 31 located below. When the cell is subjected to severe vibration or impact, this structure limits the lateral sway of the top of the electrode group 3, preventing fatigue fracture at the root of the tab 31 due to excessive bending.

[0071] like Figure 5As shown, in some embodiments, the cell cover 1 further includes a protective member 13, which is disposed on the side of the insulating member 16 away from the cover body 11, to press and fix the tabs 31 of the electrode group 3 onto the connecting portion 151 of the pole post 15. The pole post 15 and its connecting portion 151 are an integral structure to simplify the installation process and improve production efficiency. The protective member 13 generally covers the tabs 31 and their solder marks and applies appropriate clamping force. Firmly pressing the tabs 31 onto the pole post 15 effectively prevents the tabs 31 from shifting or loosening due to vibration or impact during the use of the cell; and protects the connecting portion 151 of the tabs 31 from external mechanical interference, reducing the risk of tearing of the tabs 31 or cracking of solder joints due to the movement of the electrode group 3. The protective member 13 can be kept pressed throughout the entire life cycle of the cell. This ensures that the connection point between tab 31 and post 15 is 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 cell under harsh working conditions.

[0072] This invention also provides a battery cell, such as... Figure 6 and Figure 7 As shown, the battery cell includes: a battery cell housing 2, a battery cell cover plate 1, and an electrode assembly 3. The battery cell housing 2 has an opening at its first end and an explosion-proof valve 14 at its second end; the cover plate body 11 is disposed at the opening and forms a receiving cavity with the battery cell housing 2.

[0073] Specifically, the cell housing 2 is a hollow cylinder with an opening at the first end for inserting the electrode assembly 3 and sealing the cell cover plate 1. An explosion-proof valve 14 is located at its second end (the end opposite the opening). This explosion-proof valve 14 can rupture and release pressure in a timely manner when the internal pressure of the cell abnormally rises to a safety threshold, preventing the housing from bursting and providing crucial safety protection. Positioning the explosion-proof valve 14 at the bottom of the housing avoids openings in the cover plate, simplifies the cover plate structure, and keeps it away from the electrical connection area, improving reliability. The periphery of the cover plate body 11 and the edge of the opening in the cell housing 2 are permanently sealed together by laser welding or other methods, forming a sealed cavity for containing the electrolyte and electrode assembly 3. The electrode post 15 on the cover plate has its first end protruding upwards from the reference surface 111 of the cover plate body 11, serving as an external electrical connection interface; its second end extends downwards, passing through the cover plate body 11 and entering the cavity. Inside the cell, the tabs 31 (positive tab 31 and negative tab 31) of the electrode group 3 are firmly connected to the second end of the corresponding pole post 15 through processes such as welding, thereby drawing out the current of the electrode group 3.

[0074] The battery cell provided in this embodiment, due to the aforementioned cell cover plate 1, ensures that when the cell is integrated into a battery module or battery pack, the top surface of the support boss 112 contacts the inner wall of the upper casing before the terminal post 15, thus becoming the main load-bearing and support structure. When the battery pack is subjected to external impact or vibration, the impact force acts directly and over a large area through the upper casing onto multiple support bosses 112, rather than being concentrated and borne solely by the terminal post 15. This effectively avoids deformation, damage, or internal connection failure that may occur to the terminal post 15 due to direct force, fundamentally reducing the risk of short circuits caused by damage to the terminal post 15.

[0075] Meanwhile, by incorporating multiple support protrusions 112, the contact between the cover plate body 11 and the upper casing of the battery pack is transformed from a traditional point contact to a multi-point surface contact. The support protrusions 112 provide additional heat conduction channels. Heat can be conducted from inside the battery cell through the cover plate body 11 to the support protrusions 112, and then rapidly dissipated through the direct contact between the support protrusions 112 and the upper casing, significantly increasing the effective heat dissipation area.

[0076] In addition, by adjusting the parameter settings on the cell cover plate 1, it is ensured that the support boss 112 has a sufficient overall projected area to provide effective support and heat dissipation, while the limitation of the pole hole area ensures the strength of the pole 15 mounting area.

[0077] In some embodiments, such as Figure 7 As shown, the second end surface of the battery cell housing 2 is provided with reinforcing ribs 12, which are arranged around the explosion-proof valve 14.

[0078] Specifically, the reinforcing rib 12, based on the geometric center of the explosion-proof valve 14, forms a closed or semi-closed reinforcing band around the mounting groove of the explosion-proof valve 14 or the outer periphery of the explosion-proof valve 14 body. For example, when the explosion-proof valve 14 has a circular structure, the reinforcing rib 12 can be designed as a concentric annular rib, with its inner edge maintaining a certain safe distance from the outer edge of the mounting groove of the explosion-proof valve 14 (to avoid interfering with the pressure relief path of the explosion-proof valve 14), and its outer edge extending to the flat area at the bottom of the housing where no mounting groove is provided, forming a surrounding protective ring; if the explosion-proof valve 14 has a rectangular or other irregular structure, the reinforcing rib 12 can be adapted to its contour design as a rectangular frame or a chamfered border rib, ensuring coverage of all potential stress concentration areas around the explosion-proof valve 14. Structurally, the reinforcing rib 12 is integrally formed on the metal sheet of the battery cell housing 2 by stamping or cold extrusion, presenting as a strip-shaped rib protruding along the surface of the housing. Its cross-sectional shape is preferably trapezoidal.

[0079] In one specific embodiment, as shown in Table 1 below, the length of the cover plate body 11 in its width direction is W1, the length of a single support boss 112 in the width direction of the cover plate body 11 is W2, the thickness of the cover plate body 11 is T1, the thickness of the cover plate body 11 at the edge of the pole hole is T2, the thickness of the inclined sidewall is T3, the thickness of the top wall is T4, the height of the support boss 112 protruding from the reference surface 111 is H1, the height of the first end of the pole 15 protruding from the reference surface 111 is H0, and the height of the support boss 112 above the first end of the pole 15 is H2. On the projection plane perpendicular to the reference surface 111, the projected area of ​​the cover plate body 11 on the plane where the reference surface 111 is located is S1, the sum of the projected areas of all support bosses 112 is S2, and the projected area of ​​the pole hole through which the pole 15 passes is S3.

[0080] Table 1 W1 (mm) W2 (mm) (W1-W2) / 2 (mm) T1 (mm) T2 (mm) T3 (mm) T4 (mm) H1 (mm) H2 (mm) <![CDATA[S1(mm 2 )]]> <![CDATA[S2(mm 2 )]]> <![CDATA[S3(mm 2 )]]> T2 / T1 T3 / T1 T4 / T1 S2 / S1 S3 / S1 Example 1 25 19 3 2 1.6 1.4 1.7 3.5 1.5 13245 3542 204 0.80 0.70 0.85 0.27 0.015 Example 2 28 18.5 4.75 2 1.5 1.45 1.65 3.5 1.5 13245 3650 254 0.75 0.73 0.83 0.28 0.019 Example 3 28 18 5 2 1.4 1.5 1.8 3.8 1.6 13245 3876 276 0.70 0.75 0.90 0.29 0.021 Example 4 40 27.8 6.1 2.2 1.6 1.8 1.8 3.8 1.8 14690 4135 276 0.73 0.82 0.82 0.28 0.019 Example 5 40 27 6.5 2.2 1.55 1.7 1.9 4.2 2 14690 4435 290 0.70 0.77 0.86 0.30 0.020 Example 6 55 39.2 7.9 2.3 1.7 1.6 2 4.2 2.2 14690 3712 316 0.74 0.70 0.87 0.25 0.022 Example 7 55 39 8 2.5 2 1.8 2.1 4.5 2.4 15769 4567 475 0.80 0.72 0.84 0.29 0.030 Example 8 68 55 6.5 2.5 1.8 2 1.9 4.5 2.6 15769 4489 414 0.72 0.80 0.76 0.28 0.026 Example 9 68 52 8 2.5 1.75 2.1 1.8 4 2.8 15769 5092 449 0.70 0.84 0.72 0.32 0.028 Example 10 75 60 7.5 2.5 1.9 1.9 1.75 4 3 15769 5576 408 0.76 0.76 0.70 0.35 0.026 Comparative Example 1 55 39.2 7.9 2.3 1.7 1.5 2 4.2 2.2 14690 3712 316 0.74 0.65 0.87 0.25 0.022 Comparative Example 2 75 60 7.5 2.5 1.9 1.9 1.7 4 3 15769 5576 408 0.76 0.76 0.68 0.35 0.026 Comparative Example 3 55 39 8 2.5 2 1.8 2.1 4.5 2.4 15769 4567 499 0.80 0.72 0.84 0.29 0.032 In Comparative Example 1, the ratio of the inclined sidewall thickness T3 to the substrate thickness T1, T3 / T1, is 0.65, which is lower than the lower limit of 0.7. The assembly of the cell cover plate is normal, but simulation analysis shows that when subjected to Z-axis (vertical) impact, the top of the support boss undergoes slight deformation, and the structural strength does not meet the design requirements.

[0081] In Comparative Example 2, the ratio of the top wall thickness T4 to the substrate thickness T1, T4 / T1, is 0.68, which is lower than the lower limit of 0.7. The assembly of the cell cover plate is normal, but simulation analysis shows that under Z-axis impact, the top of the support boss undergoes slight deformation, and the structural strength does not meet the design requirements.

[0082] In Comparative Example 3, the ratio of the electrode hole area S3 to the projected area S1 of the cover plate, S3 / S1≈0.032, is higher than the upper limit of 0.03. The cell cover plate assembly is normal, but simulation analysis shows that when subjected to Z-axis impact, the aluminum sheet (cover plate body) undergoes slight deformation, and the structural strength does not meet the design requirements.

[0083] As can be seen from Examples 1-10, when the cell cover adopts the multiple supporting boss structure with a specific area ratio (0.25≤S2 / S1≤0.35, 0.015≤S3 / S1≤0.03) proposed in this invention, and simultaneously meets the design requirements for a series of parameters such as the cover substrate thickness T1, the wall thickness ratio of each part (T2 / T1, T3 / T1, T4 / T1), the height difference H2, and the width difference (W1-W2), the cover not only has no interference and high yield in production assembly, but more importantly, it exhibits good structural strength in the simulated test at the battery pack level, effectively resisting external forces such as vibration and impact, and ensuring the safety of the cell.

[0084] The results of Comparative Examples 1-3 strongly demonstrate that the parameter range defined in this embodiment is necessary and not obvious. Once the key parameters, especially those involving local strength (such as T3 / T1, T4 / T1) or global strength (such as S3 / S1), deviate from the scope protected by this invention, even if other parameters meet the requirements, the cover plate will deform first at the corresponding weak point (top of the boss or the aluminum sheet) when under stress, failing to meet the safety design standards for high-reliability power batteries.

[0085] 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, and a plurality of support protrusions are formed on the reference surface along the length direction of the cover plate body. Each support protrusion protrudes from the reference surface, and a pole hole is formed between at least two adjacent support protrusions. A pole post, passing through the pole post hole, is located between two adjacent support bosses therein, with one end of the pole post 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 post protruding from the reference surface; Wherein, on the projection plane perpendicular to the reference plane, the projected area of ​​the cover plate body on the plane where the reference plane is located is S1, the sum of the projected areas of all the supporting bosses is S2, and the projected area of ​​the pole hole through which the pole passes is S3, satisfying: 0.25≤S2 / S1≤0.35, 0.015≤S3 / S1≤0.

03.

2. The cell cover plate according to claim 1, characterized in that, The support boss is provided in three parts and is arranged at both ends and the middle of the reference surface along the length of the cover plate body; the pole post is provided in two parts and the two pole posts pass through the corresponding pole post holes respectively.

3. The cell cover plate according to claim 2, characterized in that, Along the length of the cover plate body, the distance between the pole post and the adjacent support boss is A, which satisfies A≥4mm.

4. The cell cover plate according to claim 1, characterized in that, In the height direction of the cover plate body, the distance by which the support boss protrudes from the reference surface is H1, the distance by which the first end of the pole protrudes from the reference surface is H0, and the distance by which the support boss is higher than the first end of the pole is H2, satisfying 1.5mm≤H2=(H1-H0)≤3mm.

5. The cell cover plate according to claim 4, characterized in that, The length of the cover plate body in the width direction is W1, and the length of a single support boss in the width direction is W2, satisfying: 6mm≤(W1-W2)≤16mm.

6. The cell cover plate according to claim 5, characterized in that, The thickness of the cover plate body is T1, which satisfies 2.0mm≤T1≤2.5mm.

7. The cell cover plate according to claim 6, characterized in that, The supporting boss is a conical boss, which includes a top wall and an inclined side wall surrounding the top wall and connected to the reference surface; The thickness of the cover plate body at the edge of the pole hole is T2, the thickness of the inclined sidewall is T3, and the thickness of the top wall is T4, satisfying the following relationships: 0.7≤T2 / T1≤0.8, 0.7≤T3 / T1≤0.85, 0.7≤T4 / T1≤0.

9.

8. The cell cover plate according to claim 1, characterized in that, The support boss has a cavity formed on the side opposite to the reference plane; The cell cover plate also includes: An insulating component is disposed on the side of the cover plate body opposite to the reference surface. The insulating component has a groove formed at the position of the cavity. The groove is disposed in the cavity. The gap between the side wall of the groove and the side wall of the cavity is B, which satisfies B≥1mm.

9. A battery cell, characterized in that, include: The battery cell casing has an opening at the first end and an explosion-proof valve at the second end. The cell cover plate as described in any one of claims 1-8, wherein the cover plate body is disposed at the opening and surrounds the cell housing to form a receiving cavity; the first end of the electrode post protrudes from the side of the cover plate body away from the cell housing, and the second end of the electrode post extends into the receiving cavity; An electrode assembly is disposed within the receiving cavity, and the electrode tabs of the electrode assembly are connected to the second end of the electrode post.

10. The battery cell according to claim 9, characterized in that, The second end surface of the battery cell housing is provided with reinforcing ribs, which are arranged around the explosion-proof valve.

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