Battery cover plate assembly and power battery

Abstract

The application provides a battery cover plate assembly and a power battery, and relates to the technical field of batteries.The battery cover plate assembly comprises a top cover, wherein the top cover is provided with a mounting hole, and the bottom surface edge of the mounting hole is provided with a chamfer structure; an explosion-proof valve is fixedly arranged on the bottom surface of the top cover and corresponds to the mounting hole; the explosion-proof valve comprises a mounting portion, a thinning portion and a breaking portion; the mounting portion is annular; the breaking portion is arranged on the inner side of the mounting portion; the thinning portion is located between the mounting portion and the breaking portion; the thickness of the breaking portion is smaller than that of the thinning portion; the thickness of the thinning portion is smaller than that of the mounting portion; the thinning portion corresponds to the chamfer structure; the bottom surface of the explosion-proof valve is provided with a first annular notch; and at least a part of the first annular notch corresponds to the thinning portion. Through cooperation between the thinning portion and the chamfer structure, sufficient buffer space can be provided for the explosion-proof valve, so that the energy of electrolyte impact can be dissipated and effectively absorbed in the explosion-proof valve, thereby reducing the risk of breakage during falling.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery cover assembly and a power battery. Background Art

[0002] Power batteries are the core components of new energy vehicles. With the rapid development of my country's new energy vehicle industry, the requirements for power batteries are becoming higher and higher. An explosion-proof valve is usually installed on the battery cover so that when a certain amount of heat accumulates inside the battery, the explosion-proof valve will open in time to release the internal pressure of the battery.

[0003] Currently, battery drop tests often involve the risk of explosion-proof valves cracking, leading to electrolyte leakage. This is primarily because the energy from the floating electrolyte during the drop process is converted into energy that impacts the explosion-proof valve. However, explosion-proof valves must crack under a certain pressure, and their design has a certain limit on the residual thickness.

[0004] Possible solutions include reducing the injection volume, changing the explosion-proof valve, top cover, and lower plastic design. However, each of these approaches presents certain challenges. Specifically, reducing the injection volume is less effective and may even affect battery cell performance. Changing the top cover design, such as improving the material and reducing its hardness, can reduce the risk of rupture, but it can significantly reduce the mechanical strength of the top cover, seriously affecting the safe use of the battery cell and increasing design and development time and costs. Changing the explosion-proof valve design, such as increasing its area or adding reinforcing ribs, can also reduce the risk, but this can increase the cost of a single-piece explosion-proof valve and the cost of mass production.

[0005] Therefore, at this stage, how to reduce the impact of the electrolyte on the explosion-proof valve during the falling process and cause cracking has become a difficult problem. Summary of the Invention

[0006] In view of this, the present invention proposes a battery cover assembly and a power battery to solve the problem of how to reduce the cracking caused by the impact of the electrolyte on the explosion-proof valve during the battery falling process.

[0007] The technical solution of the present invention is achieved as follows:

[0008] In a first aspect, the present invention provides a battery cover assembly, comprising:

[0009] A top cover, wherein the top cover is provided with a mounting hole, and the bottom edge of the mounting hole has a chamfered structure;

[0010] An explosion-proof valve is fixedly arranged on the bottom surface of the top cover and corresponds to the mounting hole. The explosion-proof valve includes a mounting portion, a thinning portion and a rupture portion. The mounting portion is annular, and the rupture portion is arranged on the inner side of the mounting portion. The thinning portion is located between the mounting portion and the rupture portion. The thickness of the rupture portion is less than the thickness of the thinning portion, and the thickness of the thinning portion is less than the thickness of the mounting portion. The thinning portion corresponds to the chamfered structure. The bottom surface of the explosion-proof valve has a first annular notch, and at least a portion of the first annular notch corresponds to the thinning portion.

[0011] On the basis of the above technical solution, preferably, the bottom surface of the top cover has a mounting groove, the mounting groove is located on the outer peripheral side of the mounting hole, the chamfered structure is located at the junction of the mounting groove and the mounting hole, the mounting portion is fixedly arranged in the mounting groove, the width of the mounting portion is greater than or equal to the width of the mounting groove, and the width of the mounting portion is less than half of the sum of the width of the mounting groove plus the projection width of the chamfered structure on the horizontal plane.

[0012] Furthermore, preferably, the total length of the thinning portion and the mounting portion is greater than or equal to the sum of the width of the mounting groove and the projection width of the chamfered structure on the horizontal plane.

[0013] Further, preferably, the intersection of the thinning portion and the mounting portion corresponds to the first annular notch, the width of the first annular notch is l, and the depth of the first annular notch is h, wherein 0.4mm≤l≤0.7mm, 0.2mm≤h≤0.28mm.

[0014] Furthermore, preferably, the depth of the thinned portion is t, 0.2 mm ≤ t ≤ 0.5 mm.

[0015] Based on the above technical solution, preferably, the chamfer structure has a first chamfer and a second chamfer connected to each other, the first chamfer is a chamfered angle or a rounded angle, the second chamfer is a chamfered angle, the second chamfer is located at the bottom edge of the mounting groove and the edge of the mounting hole, and the first chamfer is located at the second chamfer and the edge of the mounting hole.

[0016] Further, preferably, the radius of the first chamfer is 0.1 mm to 0.3 mm, the length of the second chamfer is 0.5 mm to 1 mm, and the angle formed between the second chamfer and the bottom surface of the top cover is 20° to 35°.

[0017] Based on the above technical solution, preferably, the top surface of the rupture portion has a second annular notch, the depth of the second annular notch is 70% to 80% of the thickness of the rupture portion, and the depth and width of the first annular notch are both greater than the depth and width of the second annular notch.

[0018] On the basis of the above technical solution, preferably, it further includes a lower plastic arranged on the bottom surface of the top cover, the lower plastic has a through hole at the position corresponding to the explosion-proof valve, the area of ​​the through hole is larger than the area of ​​the explosion-proof valve, a blocking plate is fixedly provided on the through hole, and a channel is provided between the blocking plate and the through hole, and at least a portion of the first annular notch is opposite to the channel.

[0019] In a second aspect, the present invention provides a power battery, comprising the battery cover assembly described in the first aspect.

[0020] The present invention has the following beneficial effects compared to the prior art:

[0021] (1) The battery cover assembly disclosed in the present invention can provide sufficient buffer space for the explosion-proof valve through the cooperation of the thinning portion and the chamfered structure, so that the energy of the electrolyte impact can be dispersed inside the explosion-proof valve and effectively absorbed, thereby reducing the risk of rupture during the fall. Due to the deformation space of the thinning portion and the chamfered structure, the ruptured part of the explosion-proof valve will not be damaged prematurely due to excessive impact energy, which not only improves the reliability of the explosion-proof valve, but also ensures that the rupture time and method of the ruptured part are more controllable. By guiding the impact energy of the electrolyte to the thinning portion and absorbing it, the problem of explosion-proof valve rupture in accidents such as falling of the battery can be effectively avoided, which significantly improves the overall safety of the battery.

[0022] (2) By setting the chamfered structure at the intersection of the mounting groove and the mounting hole, the width of the mounting portion is greater than or equal to the width of the mounting groove, and the width of the mounting portion is less than half of the sum of the width of the mounting groove and the width of the chamfered structure projected on the horizontal plane. This structural setting makes the minimum width of the mounting portion consistent with the width of the mounting groove, so that the connection between the mounting portion and the thinning portion just corresponds to the connection between the chamfered structure and the mounting groove. At this time, the thinning portion as a whole corresponds to the chamfered structure. In this way, the thinning portion can be concave in the direction of the chamfered structure when it is deformed, and the chamfered structure effectively provides space to absorb and disperse the impact force of the thinning portion. The maximum width of the mounting portion does not exceed half of the sum of the width of the mounting groove and the width of the chamfered structure projected on the horizontal plane. In this way, at least half of the chamfered structure can correspond to the thinning portion. When the battery falls, the kinetic energy of the electrolyte is transmitted to the mounting groove area through the bottom surface of the explosion-proof valve, and the impact force is dispersed and transmitted to the mounting portion and the thinning portion through the chamfered structure, and is finally effectively absorbed at the thinning portion.

[0023] (3) The total length of the thinning portion and the mounting portion is greater than or equal to the sum of the mounting slot width and the horizontal plane projection width of the chamfer structure, so that when the thinning portion is deformed in a concave shape and completely fits the chamfer structure, the intersection of the thinning portion and the breaking portion continues to be concave in the mounting hole, so that the thinning portion pulls the breaking portion to continue to deform, thereby increasing the deformation area of the thinning portion, thereby further dispersing the impact pressure on the breaking portion and absorbing the impact energy, greatly reducing the risk of premature cracking of the breaking portion caused by the impact of the electrolyte.

[0024] (4) The intersection of the thinning portion 22 and the mounting portion 21 corresponds to the first annular notch 24, which can ensure that part of the impact force will occur in the first annular notch area when the electrolyte impacts, and the impact force acts on the first annular notch 24, thereby driving the mounting portion 21 and the thinning portion 22 to deform towards the chamfer structure 12. Since the mounting portion 21 and the thinning portion 22 both have a portion corresponding to the first annular notch 24, the thickness of the region of the mounting portion 21 and the thinning portion 22 corresponding to the first annular notch 24 will be thinned. In this way, the electrolyte impacting the first annular notch 24 can cause the corresponding mounting portion 21 and thinning portion 22 to deform towards the chamfer structure 12.

[0025] (5) The depth of the thinning portion cooperates with the design of the first annular notch, the chamfer structure, etc. to form a complete impact absorption mechanism. The depth of the thinning portion, the design of the notch, and the cooperation of the chamfer structure can effectively disperse the impact force through these areas, reducing the impact on the breaking portion. By precisely controlling the depth of the thinning portion, the width and depth of the notch, and the synergistic effect of the chamfer structure, the impact resistance of the explosion-proof valve when facing the impact of the electrolyte is significantly improved.

[0026] (6) By setting the first chamfer, the first chamfer provides a transition for the thinning portion when deforming and deforming into the mounting hole, reducing stress concentration and avoiding sharp edges causing cracks. The second chamfer provides sufficient space for the thinning portion to deform and provides sufficient area to disperse the deformation stress of the thinning portion.

[0027] (7) The depth and width of the first annular notch are greater than the depth and width of the second annular notch, so that the impact force of the electrolyte is first applied to the first annular notch, thereby realizing that when the explosion-proof valve deforms, the impact force is applied to the thinning portion through the first annular notch, and the chamfer structure provides space for the deformation of the thinning portion, thereby absorbing and dispersing the deformation force of the thinning portion, reducing the impact of the electrolyte on the second annular notch, and avoiding the electrolyte impacting the breaking portion prematurely.

[0028] (8) A through hole is provided on the lower plastic, and a blocking plate is provided on the through hole, with a channel between the blocking plate and the through hole, and at least a portion of the first annular notch faces the channel. Thus, when the battery falls, the kinetic potential energy of the electrolyte will be weakened by the blocking plate, thereby reducing the impact energy of the electrolyte, thereby reducing the direct effect of the electrolyte on the rupture portion. By corresponding the channel and the first annular notch, the impact force of the electrolyte can be first applied to the first annular notch. In this way, part of the impact force received by the first annular notch acts on the mounting portion, and part acts on the thinning portion, so that the mounting portion and the thinning portion are deformed toward the chamfered structure at the same time, and the impact force is absorbed by the chamfered structure, thereby avoiding the risk of the rupture portion cracking prematurely due to the electrolyte directly impacting the rupture portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 This is a schematic diagram of the three-dimensional structure of the battery cover assembly disclosed in the present invention from a first perspective;

[0031] Figure 2 This is a schematic diagram of the three-dimensional structure of the battery cover assembly disclosed in the present invention from a second perspective;

[0032] Figure 3 This is a schematic diagram of the three-dimensional structure of the top cover disclosed in the present invention;

[0033] Figure 4 It is a schematic diagram of the three-dimensional structure of the explosion-proof valve disclosed in the present invention;

[0034] Figure 5 A top view of the battery cover assembly disclosed in the present invention;

[0035] Figure 6 for Figure 5 Plane section view at AA in the middle;

[0036] Figure 7 for Figure 6 A partial enlarged view of point B in the middle;

[0037] Figure 8 This is a schematic diagram of the size identification of the top cover and explosion-proof valve disclosed in the present invention;

[0038] Figure 9 This is a simulation diagram of the explosion-proof valve of the battery cover assembly in the prior art being impacted by the electrolyte;

[0039] Figure 10 This is a simulation diagram of the explosion-proof valve of the battery cover assembly of the present invention being impacted by electrolyte;

[0040] Reference numerals:

[0041] 1. Top cover; 11. Mounting hole; 12. Chamfered structure; 13. Mounting groove; 121. First chamfer; 122. Second chamfer; 2. Explosion-proof valve; 21. Mounting portion; 22. Thinning portion; 23. Rupture portion; 24. First annular notch; 25. Second annular notch; 3. Lower plastic; 31. Through hole; 32. Blocking plate; 30. Channel. DETAILED DESCRIPTION

[0042] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0043] like Figure 1 As shown, combined Figure 2-7 An embodiment of the present invention discloses a battery cover assembly, including a top cover 1 and an explosion-proof valve 2.

[0044] The top cover 1 is a plain aluminum sheet, and a through mounting hole 11 is provided on the top cover 1 . The bottom edge of the mounting hole 11 has a chamfered structure 12 , the purpose of which is to provide a deformation accommodating space for the explosion-proof valve 2 .

[0045] The explosion-proof valve 2 is fixedly arranged at the mounting hole 11 on the bottom surface of the top cover 1. The explosion-proof valve 2 includes a mounting portion 21, a thinning portion 22 and a rupture portion 23. The mounting portion 21 is annular, and the rupture portion 23 is arranged on the inner side of the mounting portion 21. The thinning portion 22 is located between the mounting portion 21 and the rupture portion 23. The thickness of the rupture portion 23 is less than the thickness of the thinning portion 22. The thickness of the thinning portion 22 is less than the thickness of the mounting portion 21. The thinning portion 22 corresponds to the chamfered structure 12.

[0046] The mounting portion 21 is welded to the bottom surface of the top cover 1, and the rupture portion 23 is designed to rupture when the internal pressure of the battery is too high, allowing the internal gas or electrolyte to escape. When the battery is dropped, the electrolyte will carry a certain amount of kinetic energy due to inertial motion. When the battery cover assembly is impacted by external force, the kinetic energy of the electrolyte will be transferred to the bottom surface of the explosion-proof valve 2. The electrolyte will first act on the rupture portion 23 of the explosion-proof valve 2, causing the rupture portion 23 to sag toward the mounting hole 11. Because the rupture portion 23 is a weak area, it will first absorb the impact force and deform. When the rupture portion 23 is impacted and begins to sag, the force will spread to the surrounding area and act on the thinned portion 22. The provision of the thinned portion 22 enables this area to more effectively absorb the impact energy and deform. At the same time, the presence of the thinned portion 22 controls the stress transfer path, ensuring that the kinetic energy of the electrolyte does not directly act on the central area of ​​the rupture portion 23, thereby preventing the rupture portion 23 from prematurely cracking due to excessive impact.

[0047] The chamfered structure 12 at the mounting hole 11 on the bottom surface of the top cover 1 provides additional space, allowing the thinned portion 22 more room to deform when impacted by the electrolyte. When the thinned portion 22 deforms, the chamfered structure 12 helps disperse the impact force and prevents this deformation from being restricted by the material of the top cover 1 or other parts. The provision of the chamfered structure 12 enhances the energy absorption capacity of the thinned portion 22, enabling it to more effectively buffer impact energy.

[0048] The bottom surface of explosion-proof valve 2 has a first annular notch 24, at least a portion of which corresponds to the thinned portion 22. This notch 24 further directs the electrolyte's force, ensuring that the impact energy is transferred along the thinned portion 22 rather than directly to the rupture portion 23. Due to the presence of this notch 24, the electrolyte's impact force not only acts on the thinned portion 22 but also causes both the thinned portion 22 and the rupture portion 23 to dent, preventing the rupture portion 23 from prematurely rupturing due to excessive impact.

[0049] The battery cover assembly disclosed in the present invention, through the cooperation between the thinning portion 22 and the chamfered structure 12, can provide sufficient buffer space for the explosion-proof valve 2, so that the energy of the electrolyte impact can be dispersed inside the explosion-proof valve 2 and effectively absorbed, thereby reducing the risk of rupture during the fall. Due to the deformation space of the thinning portion 22 and the presence of the chamfered structure 12, the rupture portion 23 of the explosion-proof valve 2 will not be damaged prematurely due to excessive impact energy, which not only improves the reliability of the explosion-proof valve 2, but also ensures that the rupture time and method of the rupture portion 23 are more controllable. By guiding the impact energy of the electrolyte to the thinning portion 22 and absorbing it, the problem of rupture of the explosion-proof valve 2 in accidents such as falling can be effectively avoided, significantly improving the overall safety of the battery.

[0050] As some preferred embodiments, the top cover 1 of the embodiment is further provided with a mounting groove 13 located at the outer circumferential side of the mounting hole 11, and the mounting portion 21 is fixedly arranged in the mounting groove 13. By arranging the mounting groove 13, the mounting portion 21 can be welded in the mounting groove 13, so as to reliably fix the entire explosion-proof valve 2 on the bottom surface of the mounting hole 11, and avoid displacement or loosening of the explosion-proof valve 2 during use.

[0051] The chamfer structure 12 is located at the joint of the mounting groove 13 and the mounting hole 11, the width of the mounting portion 21 is greater than or equal to the width of the mounting groove 13, and the width of the mounting portion 21 is less than half the sum of the width of the mounting groove 13 and the horizontal projection width of the chamfer structure 12. By arranging the mounting portion 21 with the minimum width and the mounting groove 13 with the same width, the joint of the mounting portion 21 and the thinning portion 22 corresponds to the joint of the chamfer structure 12 and the mounting groove 13, so that the mounting portion 21 is matched and welded with the mounting groove 13, and the mounting portion 21 and the mounting groove 13 have sufficient welding area and improved welding strength. At the same time, the thinning portion 22 corresponds to the chamfer structure 12 as a whole, so that the thinning portion 22 can be concave to the chamfer structure 12 when deformed, and the chamfer structure 12 can effectively provide space to absorb and disperse the impact force of the thinning portion 22.

[0052] In addition, the width of the mounting portion 21 is not more than half the sum of the width of the mounting groove 13 and the horizontal projection width of the chamfer structure 12, so that at least half of the chamfer structure 12 can correspond to the thinning portion 22. When the battery falls, the kinetic energy of the electrolyte is transmitted to the bottom area of the mounting portion 21 and the thinning portion 22 through the bottom surface of the explosion-proof valve 2, the joint of the mounting portion 21 and the thinning portion 22 is deformed to the chamfer structure 12, the chamfer structure 12 provides space for the deformation of the mounting portion 21 and the thinning portion 22, and disperses and absorbs the deformation impact force of the mounting portion 21 and the thinning portion 22, so that the impact force of the electrolyte is effectively absorbed at the chamfer structure through the deformation of the mounting portion 21 and the thinning portion 22, and the electrolyte impact force does not break the rupture portion 23 in advance.

[0053] As some preferred embodiments, the total length of the thinning portion and the mounting portion is greater than or equal to the sum of the width of the mounting groove and the horizontal projection width of the chamfer structure, so that when the thinning portion is deformed and completely fits the chamfer structure, the joint of the thinning portion and the rupture portion will continue to be concave to the mounting hole, so that the thinning portion pulls the rupture portion to continue to be deformed, thereby increasing the deformation area of the thinning portion, further dispersing the impact pressure on the rupture portion and absorbing the impact energy, and greatly reducing the risk of premature cracking of the rupture portion caused by the electrolyte impact.

[0054] As some preferred embodiments, the intersection of the thinning portion 22 and the mounting portion 21 corresponds to the first annular notch 24, which can ensure that when the electrolyte impacts, part of the impact force will occur in the first annular notch area, and the impact force acts on the first annular notch 24, thereby driving the mounting portion 21 and the thinning portion 22 to deform toward the chamfered structure 12. Since both the mounting portion 21 and the thinning portion 22 have a part corresponding to the first annular notch 24, the thickness of the area of ​​the mounting portion 21 and the thinning portion 22 corresponding to the first annular notch 24 will be thinned. In this way, the electrolyte impacting the first annular notch 24 can cause the corresponding mounting portion 21 and the thinning portion 22 to deform toward the chamfered structure 12 at the same time.

[0055] It is worth noting that the area of ​​the first annular notch 24 corresponding to the thinning portion 22 of this embodiment is larger than the area corresponding to the mounting portion 21. In this way, the impact force can act on the thinning portion 22 over a larger area, so that the thinning portion 22 can deform over a larger area, thereby improving the absorption and cushioning of the impact force of the electrolyte.

[0056] When the connection between the mounting portion 21 and the thinning portion 22 corresponds to the chamfered structure 12, the impact force of the electrolyte can act on the mounting portion 21 through the first annular notch 24. At this time, the elastic deformation of the thinning portion 22 is greater than the elastic deformation of the mounting portion 21. When the thinning portion 22 undergoes elastic deformation, part of the deformation force is absorbed by the chamfered structure, and the other part is transmitted to the deformed mounting portion 21, thereby avoiding impact force fracture at the connection between the thinning portion 22 and the mounting portion 21.

[0057] In this embodiment, refer to the attached Figure 8 As shown, the width of first annular notch 24 is l, and the depth of first annular notch 24 is h, where 0.4mm≤l≤0.7mm, and 0.2mm≤h≤0.28mm. A width of first annular notch 24 that is too large or too small increases the risk of rupture, which can be counterproductive. If the depth of first annular notch 24 is not deep enough, the pressure required to deform thinned portion 22 will be greater, and the electrolyte will be transferred to the weaker rupture portion 23. If the depth is too deep, this area will become the most at risk of rupture, causing it to rupture prematurely.

[0058] In this embodiment, the depth of the thinning portion 22 is t, where 0.2mm≤t≤0.5mm. The depth of the thinning portion 22 refers to the vertical depth from the top surface of the mounting portion 21 to the top surface of the thinning portion 22. The depth of the thinning portion 22 directly affects its deformation behavior and energy absorption capacity under impact. If the thinning portion 22 is too shallow (less than 0.2mm), its energy absorption effect is limited and it cannot effectively disperse external impact forces. If the thinning portion 22 is too deep (greater than 0.5mm), the battery cover structure itself may be too fragile and easily ruptured under external forces.

[0059] The primary function of the thinned portion 22 is to provide an energy absorption zone. Under external impact, this area can undergo localized deformation or crack propagation, thereby dissipating the impact force and preventing damage to the rupture portion 23. The moderate depth of the thinned portion 22 ensures appropriate deformation during impact, preventing complete structural failure. Under external impact, a thinned portion 22 depth of 0.2mm to 0.5mm effectively absorbs a certain amount of energy from the impact force while preventing excessive thinning that would reduce structural strength, thereby ensuring the safety of the entire assembly.

[0060] The depth of the thinned portion 22, combined with the first annular notch 24 and chamfered structure 12, forms a complete impact absorption mechanism. The depth of the thinned portion 22, the notch design, and the chamfered structure 12 effectively disperse the impact force through these areas, minimizing the impact on key components such as the rupture portion 23. By precisely controlling the depth of the thinned portion 22, the notch width and depth, and the synergistic effect of the chamfered structure 12, the explosion-proof valve 2 significantly improves its impact resistance when subjected to electrolyte shock.

[0061] As some preferred embodiments, the chamfer structure 12 of this embodiment has a first chamfer 121 and a second chamfer 122 connected to each other, the first chamfer 121 is a chamfered angle or a rounded angle, the second chamfer 122 is a chamfered angle, the second chamfer 122 is located at the bottom edge of the mounting groove 13 and the edge of the mounting hole 11, and the first chamfer 121 is located at the second chamfer 122 and the edge of the mounting hole 11.

[0062] By providing the first chamfer 121, when the thinned portion 22 deforms and sinks into the mounting hole 11, the first chamfer 121 provides a transition for the thinned portion 22 to deform into the mounting hole 11, reducing stress concentration and preventing cracks caused by sharp edges. The second chamfer 122 provides sufficient space for the thinned portion 22 to deform and provides sufficient area to disperse the deformation stress of the thinned portion 22.

[0063] Preferably, the first chamfer 121 is a rounded corner, so that when the thinning portion 22 is recessed into the mounting hole 11 , the thinning portion 22 can smoothly transition into the mounting hole 11 .

[0064] Preferably, the radius of first chamfer 121 is 0.1mm to 0.3mm, the length of second chamfer 122 is 0.5mm to 1mm, and the angle between second chamfer 122 and the bottom surface of top cover 1 is 20° to 35°. The small, circular shape of first chamfer 121 effectively alleviates localized stress concentration; the greater length of second chamfer 122 further optimizes force distribution and avoids localized cracks or breakage. This design effectively reduces the risk of damage caused by concentrated impact forces.

[0065] In this embodiment, the top surface of the rupture portion 23 has a second annular notch 25, and the depth of the second annular notch 25 is 70% to 80% of the thickness of the rupture portion 23. By setting the depth of the second annular notch 25, when the internal pressure of the battery meets a certain value, the pressure can break through the rupture portion 23 from the second annular notch 25, thereby releasing the battery pressure.

[0066] The depth and width of the first annular notch 24 are both greater than those of the second annular notch 25. With this arrangement, the impact force of the electrolyte can first act on the first annular notch 24, so that when the explosion-proof valve 2 is deformed, the impact force acts on the thinning portion 22 through the first annular notch 24. The chamfered structure 12 is used to provide an accommodating space for the thinning portion 22 when it is deformed, thereby absorbing and dispersing the deformation force of the thinning portion 22, reducing the excessive impact of the electrolyte on the second annular notch 25, and preventing the electrolyte impact from breaking through the rupture portion 23 in advance.

[0067] Some preferred embodiments further include a lower plastic member 3 disposed on the bottom surface of the top cover 1. The lower plastic member 3 has a through-hole 31 at a position corresponding to the explosion-proof valve 2. The area of ​​the through-hole 31 is larger than that of the explosion-proof valve 2. A blocking plate 32 is fixedly mounted on the through-hole 31. A channel 30 is defined between the blocking plate 32 and the through-hole 31. At least a portion of the first annular notch 24 faces the channel 30. With this structural arrangement, when the battery is dropped, the kinetic potential energy of the electrolyte is weakened by the blocking plate 32, thereby reducing the impact energy of the electrolyte and thereby preventing the electrolyte from directly impacting the rupture portion 23.

[0068] By corresponding the channel 30 and the first annular notch 24, the impact force of the electrolyte can be applied to the first annular notch 24 first. In this way, part of the impact force applied to the first annular notch 24 acts on the mounting portion 21, and part acts on the thinning portion 22, so that the mounting portion 21 and the thinning portion 22 are deformed toward the chamfered structure 12 at the same time, and the impact force is absorbed by the chamfered structure 12, thereby avoiding the risk of the rupture portion 23 cracking prematurely due to the electrolyte directly impacting the rupture portion 23.

[0069] Refer to the attached Figure 9 and 10 As shown, attached Figure 9 The traditional battery cover assembly structure is shown, that is, the explosion-proof valve structure without the chamfer structure and the first annular notch. It can be clearly seen that when the electrolyte is impacted, the second annular notch in the rupture part will be subjected to a large impact force, and the second annular notch will be severely deformed by pulling, posing a risk of rupture. Figure 10The battery cover plate assembly structure of the present application is shown. It can be clearly seen that the second annular notch in the rupture portion is slightly deformed and there is no cracking. At the first annular notch and the thinning portion, the thinning portion fits toward the chamfered structure, playing a buffering and energy-absorbing role.

[0070] The present invention also discloses a power battery including the battery cover assembly disclosed in the above embodiment. By chamfering the top cover 1 on which the explosion-proof valve 2 is mounted and providing a thinned portion 22 on the explosion-proof valve 2, the battery can be opened while simultaneously ensuring the safety risk of leakage from a drop, rupture, or cracking, thereby avoiding the unfavorable factors of significant structural design modifications and high costs.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A battery cover assembly, characterized in that: include: A top cover (1), wherein a mounting hole (11) is provided on the top cover (1), and a chamfered structure (12) is provided at the bottom edge of the mounting hole (11); the chamfered structure (12) is a tapered inclined surface extending outward around the bottom edge of the mounting hole (11); An explosion-proof valve (2) is fixedly arranged on the bottom surface of the top cover (1) and corresponds to the mounting hole (11). The explosion-proof valve (2) includes a mounting portion (21), a thinning portion (22) and a rupture portion (23). The mounting portion (21) is annular. The rupture portion (23) is arranged on the inner side of the mounting portion (21). The thinning portion (22) is located between the mounting portion (21) and the rupture portion (23). The thickness of the rupture portion (23) is less than the thickness of the thinning portion (22). The thickness of the thinning portion (22) is less than the thickness of the mounting portion (21). The thinning portion (22) corresponds to the chamfered structure (12). The bottom surface of the explosion-proof valve (2) has a first annular notch (24). At least a portion of the first annular notch (24) is arranged on the bottom surface of the thinning portion (22). The bottom surface of the top cover (1) is provided with a mounting groove (13), the mounting groove (13) is located on the outer peripheral side of the mounting hole (11), the chamfered structure (12) is located at the intersection of the mounting groove (13) and the mounting hole (11), the mounting portion (21) is fixedly arranged in the mounting groove (13), the width of the mounting portion (21) is greater than or equal to the width of the mounting groove (13), and the width of the mounting portion (21) is less than half of the sum of the width of the mounting groove (13) and the projection width of the chamfered structure (12) on the horizontal plane.

2. The battery cover assembly according to claim 1, wherein: The total length of the thinning portion (22) and the mounting portion (21) is greater than or equal to the sum of the width of the mounting groove (13) and the projection width of the chamfered structure (12) on a horizontal plane.

3. The battery cover assembly according to claim 1 or 2, wherein: The intersection of the thinning portion (22) and the mounting portion (21) corresponds to the first annular notch (24), and the width of the first annular notch (24) is l , the depth of the first annular notch (24) is h , where 0.4mm≤ l ≤0.7mm, 0.2mm≤ h ≤0.28mm.

4. The battery cover assembly according to claim 3, wherein: The depth of the thinned portion (22) is t , 0.2mm≤ t ≤0.5mm.

5. The battery cover assembly according to claim 2, wherein: The chamfered structure (12) has a first chamfer (121) and a second chamfer (122) connected to each other, the first chamfer (121) is a chamfered angle or a rounded angle, the second chamfer (122) is a chamfered angle, the second chamfer (122) is located at the bottom edge of the mounting groove (13) and the edge of the mounting hole (11), and the first chamfer (121) is located at the second chamfer (122) and the edge of the mounting hole (11).

6. The battery cover assembly according to claim 5, wherein: The radius of the first chamfer (121) is 0.1 mm to 0.3 mm, the length of the second chamfer (122) is 0.5 mm to 1 mm, and the angle between the second chamfer (122) and the bottom surface of the top cover (1) is 20° to 35°.

7. The battery cover assembly according to claim 3, wherein: The top surface of the rupture portion (23) has a second annular notch (25), the depth of the second annular notch (25) is 70% to 80% of the thickness of the rupture portion (23), and the depth and width of the first annular notch (24) are both greater than the depth and width of the second annular notch (25).

8. The battery cover assembly according to claim 1, wherein: The invention also includes a lower plastic (3) arranged on the bottom surface of the top cover (1), wherein the lower plastic (3) has a through hole (31) at a position corresponding to the explosion-proof valve (2), the area of ​​the through hole (31) is larger than the area of ​​the explosion-proof valve (2), a blocking plate (32) is fixedly arranged on the through hole (31), a channel (30) is provided between the blocking plate (32) and the through hole (31), and at least a portion of the first annular notch (24) is directly opposite to the channel (30).

9. A power battery, characterized in that: Comprising the battery cover assembly according to any one of claims 1 to 8.

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