Battery cover plate assembly and battery

Abstract

The invention provides a battery cover plate assembly and a battery, the battery cover plate assembly comprises: a cover plate, the cover plate is provided with a first mounting hole and a second mounting hole, the first mounting hole is arranged close to the middle of the cover plate, and the second mounting hole is arranged close to the edge of the length direction of the cover plate; the upper end of the pole protrudes upwards relative to the cover plate, and the lower end of the pole extends into the second mounting hole; the connecting piece is connected to the lower side of the cover plate, one end of the connecting piece corresponds to the second mounting hole and is connected with the pole, and the other end of the connecting piece corresponds to the first mounting hole; the sealing plate covers the first mounting hole, the sealing plate protrudes upwards relative to the cover plate, and the top end face of the sealing plate is higher than the top end face of the pole. According to the invention, the defects of short circuit caused by easy impact of the pole and low overall mechanical strength of the battery pack in the prior art can be solved, the impact resistance of the battery pack is improved, the short-circuit risk of the battery cell is reduced, the overall mechanical strength of the battery pack is enhanced, and the high requirement of a terminal product on the safety performance of the battery pack is met.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of batteries, and provides a battery cover plate assembly and a battery. BACKGROUND

[0002] In the application scenario of new energy batteries, the battery pack, as the core carrier of electric energy storage and output, directly determines the operation reliability of the terminal product (such as new energy vehicles and energy storage equipment) in terms of mechanical safety and structural stability. In the current mainstream battery pack structure, the battery cell, as an energy storage unit, is usually electrically connected to the external circuit through its own pole, that is, the battery cell only relies on the pole to form contact with the outside world, and the pole not only bears the function of electric energy transmission but also is exposed on the upper surface area of the battery pack and becomes the direct object of external impact.

[0003] Specifically, when the upper surface of the battery pack is impacted by the outside world (such as collision, falling, extrusion, etc.), since the pole is the only structure for the battery cell to contact the outside world, the impact load will directly act on the pole. The connection part of the pole and the battery cell body and the structural strength of the pole itself are usually not designed to withstand external impact, and under the action of the impact load, the pole is prone to deformation, displacement or even fracture, which in turn causes the positive and negative materials inside the battery cell to directly contact each other, resulting in short circuit of the battery cell. The short circuit of the battery cell not only causes instantaneous discharge of large current and generates a large amount of heat, but also may further induce thermal runaway, fire and other safety accidents, which seriously threatens the safety of the battery pack and the terminal product, and this problem is particularly prominent in the field of new energy vehicles which have extremely high requirements for mechanical safety. SUMMARY

[0004] The embodiments of the present application provide a battery cover plate assembly and a battery to solve the defects of the related art that the pole is prone to short circuit caused by impact and the overall mechanical strength of the battery pack is low, and to improve the impact resistance of the battery pack, reduce the risk of short circuit of the battery cell, and enhance the overall mechanical strength of the battery pack to meet the high requirements of the terminal product on the safety performance of the battery pack.

[0005] The embodiments of the present application provide a battery cover plate assembly, comprising: a cover plate, wherein a first mounting hole and a second mounting hole are arranged on the cover plate, the first mounting hole is arranged close to the middle part of the cover plate, and the second mounting hole is arranged close to the edge of the cover plate in the length direction; a pole, wherein the upper end of the pole protrudes upward relative to the cover plate, and the lower end of the pole extends into the second mounting hole; a connecting piece, which is connected to the lower side of the cover plate, one end of the connecting piece corresponds to the second mounting hole and is connected with the pole, and the other end of the connecting piece corresponds to the first mounting hole and is arranged; A sealing plate is covered on the first mounting hole, the sealing plate is protruded upward relative to the cover plate, and the top end surface of the sealing plate is higher than the top end surface of the pole column.

[0006] According to an embodiment of the present application, the height of the pole column protruding upward relative to the cover plate is H1, and the height of the sealing plate protruding upward relative to the cover plate is H2, wherein 0.8mm≤H2-H1≤2.5mm.

[0007] According to an embodiment of the present application, the length of the upper surface of the cover plate is L, the width is W, the length of the top end surface of the sealing plate is L1, and the width is W1, wherein L1 / L=0.35-0.85, and W1 / W=0.5-0.9.

[0008] According to an embodiment of the present application, the outer contour projection area of the upper surface of the cover plate is S, and the outer contour projection area of the top end surface of the sealing plate is S1, wherein S1 / S=0.4-0.75.

[0009] According to an embodiment of the present application, the sealing plate is arranged such that the stress borne by the sealing plate satisfies (1.1-1.3)F / S1<R, wherein F is the vertical force acting on the sealing plate, and R is the material yield strength of the sealing plate.

[0010] According to an embodiment of the present application, the sealing plate is arranged centrally relative to the cover plate, and the two pole columns are arranged on the two sides of the sealing plate and symmetrically at the two ends of the cover plate along the length direction.

[0011] According to an embodiment of the present application, the height of the sealing plate protruding upward relative to the cover plate is H2, and the thickness of the original plate used to make the sealing plate is T, wherein H2 / T≤3.0.

[0012] According to an embodiment of the present application, the sealing plate comprises a sealing cover part and a flange part, the flange part extends outward from the bottom end of the sealing cover part and annularly surrounds the sealing cover part, the first mounting hole is provided with a sunken annular step part, and the flange part is welded to the step part.

[0013] According to an embodiment of the present application, the outer surface and / or the inner surface of the sealing plate is provided with a reinforcing rib. The side of the sealing plate facing the connecting sheet is provided with an insulation layer.

[0014] The embodiment of the present application further provides a battery, which comprises a shell, a pole group, and the battery cover plate assembly provided by the embodiment of the present application, the pole group is arranged in the shell, and the battery cover plate assembly is installed at the top opening of the shell.

[0015] The battery cover plate assembly and the battery provided by the embodiment of the present application are characterized in that the sealing plate top surface is higher than the pole post, when the battery pack is impacted by external force, the impact load will act on the sealing plate with higher height, instead of directly acting on the pole post, which fundamentally changes the situation that the pole post is the only exposed force component in the traditional structure, and the impact energy is transferred to the sealing plate, avoiding the deformation, displacement or fracture of the pole post due to the impact, thereby preventing the positive and negative electrodes inside the battery cell from directly contacting due to the failure of the pole post, greatly reducing the risk of short circuit of the battery cell, and ensuring the use safety of the battery pack from the source.

[0016] The pole post is stably connected with the lower side of the cover plate through the connecting sheet, which not only avoids the problem that the pole post is directly exposed to the high-impact area of the cover plate in the traditional structure, but also enhances the connection strength of the pole post and the cover plate through the supporting effect of the connecting sheet, further reducing the risk of loosening of the pole post under non-impact working conditions (such as vibration and temperature change), and ensuring the continuity and reliability of the electrical connection.

[0017] The sealing plate acts as a middle force component, which can disperse the force to the whole cover plate when the impact is borne, instead of concentrating on the local area, and the edge connection of the pole post and the connecting sheet enhances the structural support of the edge of the cover plate, which forms a stable structure of the cover plate assembly with middle protection and edge support, improves the mechanical strength of the assembly itself, and further enhances the impact resistance and structural stability of the battery pack, meeting the high requirements of new energy vehicles, energy storage equipment and the like on the mechanical properties of the battery pack. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort.

[0019] Figure 1 is a structural schematic diagram of the battery provided by the embodiment of the present application.

[0020] Figure 2 is a sectional view schematic diagram of the battery provided by the embodiment of the present application.

[0021] Figure 3 is Figure 2 is an enlarged schematic diagram of the structure at A in FIG. 5.

[0022] Figure 4 is a top view schematic diagram of the cover plate and the sealing plate assembly provided by the embodiment of the present application.

[0023] Figure 5 is an assembly schematic diagram of the tab and the connecting sheet provided by the embodiment of the present application.

[0024] Figure 6 is a structural schematic diagram of a sealing plate provided by an embodiment of the present application.

[0025] Figure 7 is a top side schematic diagram of a cover plate provided by an embodiment of the present application.

[0026] Figure 8 is a bottom side schematic diagram of a cover plate provided by an embodiment of the present application.

[0027] Reference signs: 100, battery cover plate assembly; 10, cover plate; 101, first mounting hole; 102, second mounting hole; 103, stepped portion; 11, pole; 12, connecting piece; 13, sealing plate; 131, sealing cover portion; 132, flange portion; 14, tab; 15, insulation layer; 16, explosion-proof valve; 200, shell. DETAILED DESCRIPTION

[0028] The embodiments of the present application will be further described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are used to illustrate the present application, but cannot be used to limit the scope of the present application.

[0029] As shown in Figures 1 to 8 , an embodiment of the present application provides a battery cover plate assembly 100, comprising: a cover plate 10, the cover plate 10 is provided with a first mounting hole 101 and a second mounting hole 102, the first mounting hole 101 is arranged close to the middle of the cover plate 10, and the second mounting hole 102 is arranged close to the edge of the cover plate 10 in the length direction; a pole 11, the upper end of the pole 11 is protruded upward relative to the cover plate 10, and the lower end of the pole 11 extends into the second mounting hole 102; a connecting piece 12 connected to the lower side of the cover plate 10, one end of the connecting piece 12 corresponds to the second mounting hole 102 and is connected with the pole 11, and the other end of the connecting piece 12 is arranged corresponding to the first mounting hole 101; a sealing plate 13, which is covered on the first mounting hole 101, the sealing plate 13 is protruded upward relative to the cover plate 10, and the top end surface of the sealing plate 13 is arranged higher than the top end surface of the pole 11.

[0030] Specifically, the first mounting hole 101 provides a passage for the connection of the tab 14 and the connecting piece 12, and the sealing plate 13 seals the first mounting hole 101, thereby preventing external dust, water vapor and other impurities from entering the welding area, avoiding the increase of contact resistance or the failure of electrical connection due to corrosion and pollution of the welding point, and also providing physical protection for the welding area to prevent external impact from indirectly damaging the welding point, ensuring the stability of the electrical connection of the tab 14 and the connecting piece 12 after welding, and reducing the risk of power transmission loss or power failure caused by welding failure. The sealing cooperation of the pole post 11 and the second mounting hole 102 can prevent the leakage of electrolyte in the battery cell, and also prevent external water vapor from entering the battery cell to affect the electrochemical performance. The double-sealing design greatly improves the overall sealing level of the cover plate assembly, which is beneficial to prolong the service life of the battery cell and reduce the risk of safety accidents caused by sealing failure.

[0031] As shown in Figure 5 , Figure 7 and Figure 8 , an avoidance passage is provided between the connecting piece 12 and the first mounting hole 101, the tab 14 of the battery pole group is first vertically arranged through the avoidance passage, then is bent to be connected to the upper side of the connecting piece 12 and is welded to achieve electrical connection, and finally is sealed and protected by the sealing cooperation of the sealing plate 13 and the first mounting hole 101.

[0032] The sealing plate 13, as a force receiving component, can be made of light aluminum plate (such as manganese-aluminum alloy material), which is not easy to be brittle broken when subjected to external impact, and can absorb impact energy through plastic deformation, so that even if subjected to a large impact, it is not easy to be broken or fall off, ensuring the continuous and effective protection of the barrier, and further reducing the risk of impact failure of the pole post 11. The light surface design of the light aluminum plate can make the impact load more evenly distributed on the top surface of the sealing plate 13, and in combination with the toughness of the manganese-aluminum alloy, further improve the impact resistance limit of the sealing plate 13 and prolong its protection life in long-term use. Preferably, the sealing plate 13 and the cover plate 10 can be made of the same material, and the thermal expansion coefficients of the two are consistent, so that when the battery is subjected to charge and discharge cycles or environmental temperature changes, the assembly will not generate internal stress due to the difference in thermal expansion and contraction of the two materials, avoiding the increase of the gap between the sealing plate 13 and the first mounting hole 101 (leading to sealing failure) or the deformation of the sealing plate 13 (affecting the impact protection height), and also reducing the warping and cracking of the cover plate 10 due to local stress concentration, thereby ensuring the stability of the overall structure of the assembly under temperature fluctuations.

[0033] The sealing plate 13 is made of metal material, in order to realize electrical insulation protection, as shown in Figure 2 and Figure 3As shown, according to one embodiment of the present application, the sealing plate 13 is provided with an insulating layer 15 on the side facing the connecting piece 12, which can block the electrical connection path and eliminate the risk of short circuit. At the same time, the insulating layer 15 has a certain elasticity and can be used as a buffer medium to absorb vibration energy, further improving the effect of the sealing plate 13 to withstand external impact. Since the sealing plate 13 adopts an upper convex structure, a certain height of hollow space can be formed between the sealing plate 13 and the connecting piece 12 or between the insulating layer 15 and the connecting piece 12. When the upper surface of the battery pack is impacted by external force, the upper convex sealing plate 13 will preferentially bear the impact and have a certain downward deformation trend. At this time, the hollow space can be used as a buffer space to provide accommodation space for the deformation of the sealing plate 13, avoiding the direct extrusion of the sealing plate 13 (or the insulating layer 15) on the connecting piece 12 / tab 14. During the charging and discharging process of the battery cell, due to the change in temperature and the expansion and contraction of the electrode material, a slight deformation will be generated, which will indirectly cause the connecting piece 12 to slightly displace or bend. The hollow space can accommodate such deformation of the connecting piece 12, avoiding the extrusion and deformation of the connecting piece 12 due to limited space. In addition, the hollow space can effectively improve the heat dissipation efficiency, reduce the working temperature of the connecting piece 12, and ensure the stability of its electrical connection performance, avoiding the safety hazards caused by overheating.

[0034] According to one embodiment of the present application, as shown in the drawings, Figure 1 The height of the pole 11 protruding upward relative to the cover plate 10 is H1, and the height of the sealing plate 13 protruding upward relative to the cover plate 10 is H2, wherein 0.8mm≤H2-H1≤2.5mm.

[0035] Specifically, the minimum difference of 0.8mm can ensure that the sealing plate 13 always contacts the impact source before the pole 11 when the upper surface of the battery pack is impacted, forming a reliable protective barrier. If the difference is less than 0.8mm, due to the processing error of the assembly or the impact angle, the pole 11 and the sealing plate 13 may be forced at the same time or the pole 11 may be forced first, resulting in deformation of the pole 11 and an increase in the risk of short circuit. The maximum difference of 2.5mm can prevent the sealing plate 13 from deforming too much downward when it is impacted by a large impact due to being protruded too high, thereby losing its protective effect. However, the difference of 2.5mm can control the deformation of the sealing plate 13 within a safe range, which can absorb impact energy through deformation and avoid damage due to excessive deformation, ensuring that the impact protection function is stable and effective during long-term use. By limiting H2-H1≤2.5mm, the sealing plate 13 can be prevented from interfering with other components on the upper side of the battery pack due to being protruded too high.

[0036] The cover plate 10 usually adopts a rectangular shape, and the shape of the sealing plate 13 is not limited, for example, it can adopt a rectangular, circular, oval, racetrack shape, etc., which can be set according to actual needs. In the following, the sealing plate 13 is taken as an example of a rectangular shape to describe the parameter relationship between the sealing plate 13 and the cover plate 10.

[0037] According to one embodiment of the present application, as shown in Figure 4 The length of the upper surface of the cover plate 10 is L, the width is W, the length of the top end surface of the sealing plate 13 is L1, and the width is W1, wherein L1 / L = 0.35-0.85, and W1 / W = 0.5-0.9.

[0038] By limiting the range of L1 / L and W1 / W, it can be ensured that the sealing plate 13 covers the core impact area of the cover plate 10, avoids the blind area of protection, prevents the impact load from falling outside the sealing plate 13 and directly acting on the weak part of the pole 11 or the cover plate 10, and ensures that the impact risk on the upper surface of the cover plate 10 is fully controllable. The size of the sealing plate 13 under the above ratio can uniformly disperse the impact energy to a larger area, rather than concentrating on a local area, thereby reducing the probability of local damage. The cover plate 10 is a bearing base, and its strength design needs to be matched with the size and weight of the component above (the sealing plate 13). The sealing plate 13 is made of manganese-aluminum alloy aluminum plate, and the size ratio is limited in the above range, which can ensure that its weight is matched with the bearing capacity of the cover plate 10: if the ratio is too high (such as L1 / L>0.85, W1 / W>0.9), the area of the sealing plate 13 is too large, and the weight increases, which will cause the cover plate 10 to bear additional load for a long time, and the middle part is prone to sink and the edge is prone to warp, thereby affecting the overall structural stability; if the ratio is too low (such as L1 / L<0.35, W1 / W<0.5), the weight of the sealing plate 13 is too light, although it does not put pressure on the bearing of the cover plate 10, but the protection function is insufficient.

[0039] Further, the outer contour projection area of the upper surface of the cover plate 10 is S, and the outer contour projection area of the top end surface of the sealing plate 13 is S1, wherein S1 / S = 0.4-0.75.

[0040] When the upper surface of the battery pack is impacted by external force, the impact load is not uniformly distributed, but is concentrated in the middle and near-middle area of the cover plate 10. Under the above area ratio, the sealing plate 13 can accurately cover the high-risk impact area, the minimum ratio of 0.4 can cover the core impact area in the middle, avoiding the impact falling outside the sealing plate 13 and directly acting on the weak part of the pole 11 or the cover plate 10; and the maximum ratio of 0.75 can extend to the near-edge secondary high-risk area, further expand the protection range, while avoiding covering the edge pole 11 installation area and sealing structure area, to ensure that the protection has no loopholes and does not interfere with the function of other components. The ratio of S1 / S = 0.4-0.75 can meet the protection performance while controlling the cost, and for mass-produced battery components, the ratio can significantly reduce the material cost per unit product, thereby improving the market competitiveness.

[0041] According to one embodiment of the present application, the sealing plate 13 is arranged such that the stress borne by the sealing plate 13 satisfies (1.1-1.3) * F / S1 < R, wherein F is the vertical force acting on the sealing plate 13, R is the yield strength of the material of the sealing plate 13, and * represents multiplication.

[0042] Specifically, according to (1.1-1.3) * F / S1 < R, the safety factor design of (1.1-1.3) in the formula can reserve a safety margin for impact load and can cover the fluctuation of impact force in actual use. When (1.1-1.3) * F / S1 is still less than the material yield strength R, it means that the actual stress borne by the sealing plate 13 is always lower than the yield strength, which can ensure that the sealing plate 13 only undergoes elastic deformation (fully restores to its original state after the external force is removed) after being impacted and does not appear yield deformation, avoiding the subsequent impact directly acting on the pole 11 due to the deformation failure of the sealing plate 13, and ensuring the long-term integrity of the protection structure. If the sealing plate 13 bears stress close to or exceeding the yield strength for a long time, material fatigue is easy to be caused, which leads to gradual decrease of strength and shortens the service life. However, the stress condition strictly controls the gap between the actual stress and the yield strength, so that the sealing plate 13 always works in a low stress range, which can greatly reduce the risk of material fatigue and ensure that it maintains stable protection performance during the entire service cycle of the battery pack, without the need for frequent replacement and maintenance. The stress condition can be adapted to sealing plate 13 materials with different yield strengths (such as low-strength pure aluminum, medium-strength manganese-aluminum alloy, and high-strength hard aluminum), improving the design flexibility. In addition, the stress condition provides an evaluation index for the design of the sealing plate 13, which can verify the performance of the sealing plate 13 according to the formula and judge whether it is qualified, without the need for complex fatigue tests and impact life tests, greatly simplifying the performance verification process.

[0043] According to one embodiment of the present application, the sealing plate 13 is arranged centrally relative to the cover plate 10, and two poles 11 are arranged on both sides of the sealing plate 13 and symmetrically at both ends of the cover plate 10 in the length direction.

[0044] Among them, the sealing plate 13 is arranged centrally relative to the cover plate 10, that is, the centers of the two coincide, and the pole 11 is provided with two, which are distributed on the left and right sides of the sealing plate 13, as shown in Figure 1 , Figure 3 or Figure 4 , wherein one of the poles 11 is a positive pole and the other is a negative pole, and the two poles 11 are respectively arranged corresponding to the two connecting pieces 12. Of course, the number of poles 11 is not limited to this, and the number of poles 11 can also be one, that is, only one pole 11 is arranged on the cover plate 10, and this pole 11 can be a positive pole or a negative pole.

[0045] The sealing plate 13 is centrally arranged, so that the impact load on the upper surface of the battery pack is evenly applied to the middle area of the sealing plate 13, and then transmitted to the whole cover plate 10 through the sealing plate 13, thereby avoiding the impact energy from being concentrated on one side of the cover plate 10 due to the deviation of the sealing plate 13, and causing the cover plate 10 to be warped and cracked. Meanwhile, the pole posts 11 symmetrically arranged on both sides can balance the stress on the edge of the cover plate 10. When the sealing plate 13 receives the impact, the pole posts 11 on the edge of the cover plate 10 can provide symmetrical support for the cover plate 10 through the connection with the connecting pieces 12, thereby further dispersing the impact stress, preventing the cover plate 10 from being structurally deformed due to excessive stress on one side, and ensuring the overall impact resistance of the assembly. The centrally arranged sealing plate 13 and the symmetrically arranged pole posts 11 can evenly distribute the weight of the assembly on the cover plate 10, thereby avoiding the cover plate 10 from being subjected to asymmetric load for a long time due to the deviation of the weight, and causing permanent deformation such as sinking in the middle and tilting on the edge. The balanced weight distribution can ensure that the sealing cooperation between the cover plate 10 and the battery cell shell 200 is stable for a long time, avoid the sealing failure and electrolyte leakage caused by deformation, and improve the long-term structural reliability of the assembly.

[0046] According to one embodiment of the present application, the height of the sealing plate 13 protruding upward relative to the cover plate 10 is H2, and the thickness of the original plate used to manufacture the sealing plate 13 is T, wherein H2 / T≤3.0.

[0047] It should be noted that T is the thickness of the original plate used to manufacture the sealing plate 13, and the original plate is a flat plate with a thickness T, which can be processed into the required form as needed, such as the sealing plate 13 of the present application having a protruding height H2 after forming. If H2 / T>3.0, i.e., the protruding height is much greater than the thickness of the original plate, the amount of tensile deformation will exceed the reasonable range, resulting in a significant reduction in the wall thickness of the side wall, top, and other areas of the protruding structure, forming a weak strength area. The limitation of H2 / T≤3.0 can control the tensile deformation within the reasonable tensile coefficient range of the metal plate (such as manganese-aluminum alloy aluminum plate), ensuring that the wall thickness of the protruding structure of the sealing plate 13 after forming is uniform, without the risk of cracking and depression caused by local thinning, and ensuring the structural integrity. By ensuring that the protruding structure of the sealing plate 13 retains sufficient wall thickness, the load-bearing capacity thereof can be matched with the impact load demand, thereby ensuring the stable performance of the impact protection function.

[0048] According to one embodiment of the present application, the sealing plate 13 comprises a sealing cover portion 131 and a flange portion 132, the flange portion 132 extends outward from the bottom end of the sealing cover portion 131 and is arranged in a circumferential ring along the sealing cover portion 131, and the first mounting hole 101 is provided with a sunken annular step portion 103, and the flange portion 132 is welded to the step portion 103.

[0049] As Figure 5 and Figure 6As shown, the recessed annular step 103 of the first mounting hole 101 allows the flange 132 of the sealing plate 13 to be fully embedded within the step, forming an embedded fit structure. This fit eliminates the height difference between the flange 132 and the upper surface of the cover plate 10, avoiding poor sealing due to surface protrusions. Simultaneously, the step 103 provides radial positioning for the flange 132, preventing the sealing plate 13 from shifting during installation or impact, thus improving sealing reliability. Connecting the flange 132 to the step 103 increases the welding contact area, enhances the connection strength between the sealing plate 13 and the cover plate 10, and prevents the sealing plate 13 from detaching due to impact.

[0050] The upward-protruding three-dimensional structure of the sealing cover 131 naturally forms a space on its inner side to accommodate the insulating layer 15 and the connecting piece 12. The height of the sealing cover 131 can be designed according to actual needs to ensure that sufficient hollow space is reserved on the lower side. At the same time, the insulating layer 15 can be installed against the inner wall of the sealing cover 131 without occupying other space of the cover plate 10. This structural layout enables the sealing plate 13 to simultaneously provide external impact protection, internal insulation isolation, and hollow space reservation, achieving multi-functional synergy without the need for additional components, thus simplifying the component structure.

[0051] Based on the above embodiments, in order to further improve the structural strength of the sealing plate 13 and optimize its impact resistance and structural stability, reinforcing ribs can be provided on the sealing plate 13. By optimizing the stress distribution of the sealing plate 13 and improving its bending and deformation resistance, the structural strength of the sealing plate 13 is fundamentally enhanced, enabling it to maintain morphological stability even when subjected to greater impact loads, thereby further optimizing the component's impact resistance and long-term structural reliability. The form of the reinforcing ribs can be flexibly set, such as being formed by protrusions from the inner surface of the sealing plate 13 to the outer surface (recessed from the inside and raised from the outside), or being formed by protrusions from the outer surface of the sealing plate 13 to the inner surface (recessed from the outside and raised from the inside), or being raised directly from the outer / upper surface of the sealing plate 13, or being raised directly from the inner / lower surface of the sealing plate 13, depending on actual needs.

[0052] Furthermore, such as Figure 1 As shown, the battery cover assembly 100 also includes an explosion-proof valve 16. The sealing plate 13 is provided with an installation through hole for installing the explosion-proof valve 16, ensuring the safety and reliability of battery use.

[0053] This invention also provides a battery, such as... Figure 1As shown, the battery pack includes a housing 200, an electrode assembly, and a battery cover assembly 100 provided in this embodiment. The electrode assembly is disposed within the housing 200, and the battery cover assembly 100 is installed at the top opening of the housing 200. The electrode tabs 14 of the electrode assembly can be connected to the connecting piece 12 by first vertically inserting them and then bending them. The electrode tabs 14 are sealed by a sealing plate 13 covering the first mounting hole 101. The housing 200 and the cover 10 are connected around their peripheries, for example, by welding for encapsulation. Using the battery cover assembly 100 of the above embodiment can effectively improve the impact resistance of the battery pack, reduce the risk of cell short circuits, and enhance the overall mechanical strength of the pack, meeting the high safety performance requirements of end products for battery packs. The battery also possesses all the beneficial effects of the above embodiment, which will not be elaborated further here.

[0054] The battery cover assembly 100 and battery provided in this embodiment of the invention, by setting the top surface of the sealing plate 13 higher than the terminal post 11, when the battery pack is subjected to external impact, the impact load will preferentially act on the higher sealing plate 13 instead of directly acting on the terminal post 11. This design fundamentally changes the situation in the traditional structure where the terminal post 11 is the only exposed force-bearing component, transferring the impact energy to the sealing plate 13, avoiding deformation, displacement or breakage of the terminal post 11 due to impact, thereby preventing the positive and negative electrodes inside the cell from directly contacting each other due to the failure of the terminal post 11, greatly reducing the risk of short circuit in the cell, and ensuring the safety of the battery pack from the source.

[0055] The pole 11 is stably connected to the lower side of the cover plate 10 through the connecting piece 12. This avoids the problem of the pole 11 being directly exposed to the high impact area of ​​the cover plate 10 in the traditional structure. Furthermore, the supporting effect of the connecting piece 12 enhances the connection strength between the pole 11 and the cover plate 10, further reducing the risk of loosening of the pole 11 under non-impact conditions (such as vibration and temperature changes), and ensuring the continuity and reliability of the electrical connection.

[0056] As a central load-bearing component, the sealing plate 13 can distribute the force to the entire cover plate 10 when subjected to impact, rather than concentrating it in a local area. The edge connection between the pole post 11 and the connecting piece 12 enhances the structural support of the edge of the cover plate 10. This layout enables the cover plate 10 assembly to form a stable structure with central protection and edge support, improving the mechanical strength of the assembly itself, thereby enhancing the impact resistance and structural stability of the entire battery pack, and meeting the high requirements of new energy vehicles, energy storage equipment and other applications for the mechanical performance of battery packs.

[0057] The effects of the battery cover assembly 100 of the present invention are described below with reference to specific embodiments. Through multiple embodiments and comparative examples using different parameters and combined with simulation analysis, the structural performance of the battery cover assembly 100 with different size designs is evaluated.

[0058] Table 1 Comparison of parameters used in each embodiment and comparative example 120-350 mm 22-85 mm 42-297.5 mm 11-76.5 mm 0.4-0.75 1.5-3.5 mm 2.3-6.0 mm 1.5-3 mm 100000N R = 125 Mpa L W L1 W1 S1 / S H1 H2 T F 1.2 F / S1 Example 1 160 35 80 30 0.43 2.0 2.9 1.8 100000 50.0 Example 2 200 40 100 40 0.50 2.3 3.2 2.0 100000 30.0 Example 3 240 45 120 50 0.56 2.5 4.6 2.2 100000 20.0 Example 4 260 50 160 55 0.68 2.8 5.0 2.4 100000 13.6 Example 5 280 55 180 60 0.70 3.0 5.0 2.5 100000 11.1 Example 6 350 85 290 75 0.73 3.5 6.0 3.0 100000 5.5 Comparative Example 1 122 22 45 15 0.25 1.5 2.3 1.5 100000 177.8 Comparative Example 2 135 30 66 13 0.21 1.8 2.5 1.6 100000 139.9 Comparative Example 3 300 60 220 65 0.79 3.2 5.5 2.6 100000 8.4 Comparative Example 4 320 70 255 70 0.80 3.2 6.0 2.8 100000 6.7 As shown in Table 1, according to the design of the sealing plate 13 according to the embodiments of the present invention, referring to Embodiments 1 to 6, by reasonably setting the relevant parameters of the sealing plate 13 and the cover plate 10, the S1 / S is controlled within the range of 0.4-0.75, and the design requirement of 1.2F / S1 < R (R=125Mpa) is met, according to the simulation analysis, when the battery pack is subjected to a Z-direction mechanical impact of magnitude F, the upper surface of the sealing plate 13 and the upper surface of the cover plate 10 (both of which are made of light aluminum plates, for example) do not undergo significant deformation, and the structural strength of the sealing plate 13 and the cover plate 10 meets the stress requirements. Referring to Comparative Examples 1 to 4, when the area of ​​the sealing plate 13 is insufficient, resulting in 1.2F / S1 > R, simulation analysis shows that when the battery pack is subjected to a Z-axis mechanical impact of magnitude F, the stress value of the material on the upper surface of the sealing plate 13 increases, indicating that the force on the sealing plate 13 exceeds its yield strength and no longer meets the stress requirements. When 1.2F / S1 is much smaller than R, it indicates that the area of ​​the sealing plate 13 is relatively high, causing compression of the space of the terminal post 11, resulting in a reduction in the current carrying capacity of the product and a serious design imbalance.

[0059] 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 cover assembly, characterized in that, include: A cover plate, wherein the cover plate is provided with a first mounting hole and a second mounting hole, the first mounting hole being disposed near the middle of the cover plate and the second mounting hole being disposed near the edge of the cover plate along its length; The electrode post has its upper end protruding upward relative to the cover plate, and its lower end extending into the second mounting hole. A connecting piece is attached to the lower side of the cover plate. One end of the connecting piece corresponds to the second mounting hole and is connected to the pole post. The other end of the connecting piece corresponds to the first mounting hole. A sealing plate is installed in the first mounting hole. The sealing plate protrudes upward relative to the cover plate, and the top end face of the sealing plate is higher than the top end face of the pole post.

2. The battery cover assembly according to claim 1, characterized in that, The height at which the pole protrudes upward relative to the cover plate is H1, and the height at which the sealing plate protrudes upward relative to the cover plate is H2, wherein 0.8mm≤H2-H1≤2.5mm.

3. The battery cover assembly according to claim 1, characterized in that, The upper surface of the cover plate has a length of L and a width of W, and the top end face of the sealing plate has a length of L1 and a width of W1, wherein L1 / L = 0.35-0.85 and W1 / W = 0.5-0.

9.

4. The battery cover assembly according to claim 3, characterized in that, The outer contour projection area of ​​the upper surface of the cover plate is S, and the outer contour projection area of ​​the top end face of the sealing plate is S1, where S1 / S = 0.4-0.

75.

5. The battery cover assembly according to claim 4, characterized in that, The sealing plate is configured such that the stress on the sealing plate satisfies: (1.1-1.3) F / S1 < R, where F is the vertical force acting on the sealing plate and R is the yield strength of the material of the sealing plate.

6. The battery cover assembly according to claim 1, characterized in that, The sealing plate is centrally located relative to the cover plate, and the two poles are respectively located on both sides of the sealing plate and symmetrically arranged at both ends of the cover plate along its length.

7. The battery cover assembly according to claim 1, characterized in that, The height by which the sealing plate protrudes upward relative to the cover plate is H2, and the thickness of the original sheet material used to make the sealing plate is T, wherein H2 / T≤3.

0.

8. The battery cover assembly according to any one of claims 1 to 7, characterized in that, The sealing plate includes a sealing cover and a flange. The flange extends outward from the bottom end of the sealing cover and is arranged circumferentially around the sealing cover. The first mounting hole has a recessed and annular step. The flange is welded to the step.

9. The battery cover assembly according to claim 8, characterized in that, The outer and / or inner surfaces of the sealing plate are provided with reinforcing ribs; The sealing plate has an insulating layer on the side facing the connecting piece.

10. A battery, characterized in that, The device includes a housing, an electrode assembly, and a battery cover assembly as described in any one of claims 1 to 9, wherein the electrode assembly is disposed within the housing and the battery cover assembly is mounted at the top opening of the housing.

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