Battery cover plate assembly and power battery

Abstract

The invention 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, the top cover is provided with a mounting hole, and the edge of the bottom surface of the mounting hole is provided with a chamfer structure; the 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 part, a thinning part and a cracking part, the mounting part is annular, the cracking part is arranged on the inner side of the mounting part, the thinning part is located between the mounting part and the cracking part, the thickness of the cracking part is smaller than that of the thinning part, and the thickness of the thinning part is smaller than that of the mounting part; the thinning part corresponds to the chamfering structure, the bottom surface of the explosion valve is provided with a first annular nick, and at least one part of the first annular nick corresponds to the thinning part. According to the anti-explosion valve, the thinning part and the chamfering structure are matched with each other, so that enough buffer space can be provided for the anti-explosion valve, the energy of electrolyte impact can be dispersed in the anti-explosion valve and can be effectively absorbed, and the risk of fracture in the falling process is reduced.

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 provided on the battery cover so that when a certain amount of heat is accumulated inside the battery, the explosion-proof valve will open in time to release the internal pressure of the battery.

[0003] At present, the explosion-proof valve of the battery drop test has the risk of cracking, resulting in electrolyte leakage. The main reason is that the energy of the floating electrolyte during the drop process is converted into energy that impacts the explosion-proof valve, and the explosion-proof valve must crack under a certain pressure, and its design residual thickness is limited.

[0004] Possible solutions at present include reducing the amount of liquid injected, changing the explosion-proof valve, top cover, and lower plastic design. However, these methods all have certain problems. Specifically, reducing the amount of liquid injected is not very effective and may also affect the performance of the battery cell. Changing the top cover design, such as improving the top cover material and reducing hardness and strength, will reduce the risk of rupture, but will greatly reduce the mechanical strength of the top cover, seriously affecting the safe use of the battery cell, and at the same time, the design and development time cost will also increase. Changing the explosion-proof valve design, such as increasing the area or adding reinforcing ribs, can reduce the risk, but the cost of a single-piece explosion-proof valve may increase, and the cost of mass production will increase.

[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 thorny issue. 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 problem 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 in this way:

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

[0009] A top cover, wherein a mounting hole is provided on the top cover, and a 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. 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. 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] Further, 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] Further, preferably, the depth of the thinned portion is t, 0.2 mm ≤ t ≤ 0.5 mm.

[0015] On the basis of the above technical solution, preferably, the chamfer structure has a first chamfer and a second chamfer that are interconnected, the first chamfer is a chamfer or a rounded angle, the second chamfer is a chamfer, the second chamfer is located at the edge of the bottom surface 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 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 also includes a lower plastic arranged on the bottom surface of the top cover, the lower plastic has a through hole corresponding to the position of 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 arranged on the through hole, a channel is provided between the blocking plate and the through hole, and at least a part 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] Compared with the prior art, the present invention has the following beneficial effects:

[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 part 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 part 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 part and absorbing it, the problem of explosion-proof valve rupture in accidents such as falling can be effectively avoided, which significantly improves the overall safety of the battery.

[0022] (2) By setting the chamfer structure at the junction 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 projection width of the chamfer structure 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 chamfer structure and the mounting groove. At this time, the thinning portion as a whole corresponds to the chamfer structure. In this way, the thinning portion can be recessed in the direction of the chamfer structure when deformation occurs, and the chamfer 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 projection width of the chamfer structure on the horizontal plane. In this way, at least half of the chamfer 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 chamfer structure, and 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 width of the mounting groove and the projection width of the chamfer structure on the horizontal plane. According to this arrangement, when the thinning portion is concavely deformed and completely fits the chamfer structure, the junction between the thinning portion and the rupture portion will continue to be concave toward the mounting hole, so that the thinning portion pulls the rupture portion to continue to deform, thereby increasing the deformation area of ​​the thinning portion, thereby further dispersing the impact pressure on the rupture portion and absorbing the impact energy, greatly reducing the risk of premature cracking of the rupture 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 when the electrolyte impacts, a part of the impact force will occur in the first annular notch area. 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 a part of the mounting portion 21 and the thinning portion 22 corresponds to the first annular notch 24, the thickness of the mounting portion 21 and the thinning portion 22 corresponding to the first annular notch 24 will be thinned. In this way, when the electrolyte impacts the first annular notch 24, the corresponding mounting portion 21 and the thinning portion 22 can be deformed toward the chamfered structure 12 at the same time.

[0025] (5) The depth of the thinned portion is coordinated with the first annular notch, chamfer structure and other designs to form a complete impact absorption mechanism. The depth of the thinned portion, the notch design, and the chamfer structure can effectively disperse the impact force through these areas and reduce the impact on the ruptured part. By precisely controlling the depth of the thinned 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 electrolyte impact has been significantly improved.

[0026] (6) By providing the first chamfer, when the thinned portion is deformed and recessed into the mounting hole, the first chamfer provides a transition for the thinned portion to deform into the mounting hole at the second chamfer, thereby reducing stress concentration and avoiding cracks caused by sharp edges. The second chamfer provides sufficient space for the thinned portion to deform and provides sufficient area to disperse the deformation stress of the thinned portion.

[0027] (7) The depth and width of the first annular notch are greater than the depth and width of the second annular notch. With this arrangement, the impact force of the electrolyte can first act on the first annular notch, so that when the explosion-proof valve is deformed, the impact force acts on the thinned portion through the first annular notch, and the chamfered structure is used to provide an accommodation space when the thinned portion is deformed, thereby absorbing and dispersing the deformation force of the thinned portion, reducing the excessive impact of the electrolyte on the second annular notch, and preventing the electrolyte impact from breaking the ruptured portion in advance.

[0028] (8) A through hole is provided on the lower plastic, and a blocking plate is provided on the through hole, a channel is provided between the blocking plate and the through hole, and at least a portion of the first annular notch is directly opposite to 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 ruptured 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 of the impact force 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 ruptured portion cracking prematurely due to the direct impact of the electrolyte on the ruptured 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0030] Figure 1 It 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 It is a schematic diagram of the three-dimensional structure of the battery cover assembly disclosed in the present invention from a second viewing angle;

[0032] Figure 3 It 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 It is a schematic diagram of the size identification of the top cover and explosion-proof valve disclosed in the present invention;

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

[0039] Fig.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 described embodiments 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 creative work 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 is provided with a through mounting hole 11 . The bottom edge of the mounting hole 11 has a chamfered structure 12 , which is used 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. 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 chamfer structure 12.

[0046] Among them, the mounting portion 21 is used to weld with the bottom surface of the top cover 1, and the rupture portion 23 is used to rupture when the internal pressure of the battery is too high, so as to realize the leakage of internal gas or electrolyte. During the battery falling process, 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 be concave in the direction of the mounting hole 11. Since 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 be concave, the force will spread to the surroundings and act on the thinning portion 22. The setting of the thinning portion 22 enables this area to absorb the impact energy more effectively and deform. At the same time, the existence of the thinning portion 22 controls the stress transfer path, ensuring that the kinetic energy of the electrolyte will not directly act on the central area of ​​the rupture portion 23, thereby avoiding the premature cracking of the rupture portion 23 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 to have more deformation space when impacted by the electrolyte. When the thinned portion 22 is deformed, the chamfered structure 12 helps to disperse the impact force and prevents such deformation from being restricted by the material or other parts of the top cover 1. The provision of the chamfered structure 12 enhances the energy absorption capacity of the thinned portion 22, enabling it to more effectively buffer the impact energy.

[0048] The bottom surface of the explosion-proof valve 2 has a first annular notch 24, at least a portion of which corresponds to the thinned portion 22. The first annular notch 24 is used to further guide the force of the electrolyte, ensuring that the impact energy is transmitted along the direction of the thinned portion 22, rather than directly transmitted to the rupture portion 23. Due to the setting of the first annular notch 24, the impact force of the electrolyte not only acts on the thinned portion 22, but also causes the thinned portion 22 and the rupture portion 23 to be concave at the same time, thereby preventing the rupture portion 23 from rupturing prematurely due to excessive impact.

[0049] The battery cover assembly disclosed in the present invention can provide sufficient buffer space for the explosion-proof valve 2 through the cooperation between the thinning portion 22 and the chamfered structure 12, 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 existence 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, which significantly improves the overall safety of the battery.

[0050] As some preferred implementations, the bottom surface of the top cover 1 of this embodiment is further provided with a mounting groove 13, the mounting groove 13 is located on the outer peripheral side of the mounting hole 11, and the mounting portion 21 is fixedly disposed in the mounting groove 13. By providing the mounting groove 13, the mounting portion 21 can be welded in the mounting groove 13 to achieve reliable fixation of the entire explosion-proof valve 2 on the bottom surface of the mounting hole 11, thereby preventing the explosion-proof valve 2 from being displaced or loosened during use.

[0051] The chamfered structure 12 is located at the junction 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 of the sum of the width of the mounting groove 13 and the projection width of the chamfered structure 12 on the horizontal plane. This structural setting makes the minimum width of the mounting portion 21 consistent with the width of the mounting groove 13, so the connection between the mounting portion 21 and the thinning portion 22 just corresponds to the connection between the chamfered structure 12 and the mounting groove 13. At this time, the mounting portion 21 just matches the mounting groove 13 for welding, ensuring that the mounting portion 21 and the mounting groove 13 have sufficient welding area and improve the welding strength. At the same time, the thinning portion 22 corresponds to the chamfered structure 12 as a whole, so that the thinning portion 22 can be recessed toward the chamfered structure 12 when deformation occurs, and the chamfered structure 12 effectively provides space to absorb and disperse the impact force of the thinning portion 22.

[0052] In addition, the maximum width of the mounting portion 21 does not exceed half of the sum of the width of the mounting groove 13 plus the projection width of the chamfered structure 12 on the horizontal plane. In this way, at least half of the area of ​​the chamfered 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, and the connection between the mounting portion 21 and the thinning portion 22 is deformed toward the chamfered structure 12. The chamfered structure 12 provides space for the mounting portion 21 and the thinning portion 22 to deform, 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 chamfered structure through the deformation of the mounting portion 21 and the thinning portion 22, thereby preventing the impact force of the electrolyte from opening 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 plus the width of the projection of the chamfer structure on the horizontal plane. According to this arrangement, when the thinning portion is concavely deformed and completely fits the chamfer structure, the junction between the thinning portion and the ruptured portion will continue to be concave toward the mounting hole, so that the thinning portion pulls the ruptured portion to continue to deform, thereby increasing the deformation area of ​​the thinning portion, thereby further dispersing the impact pressure on the ruptured portion and absorbing the impact energy, greatly reducing the risk of premature cracking of the ruptured portion caused by the impact of the electrolyte.

[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, a 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 a part of the mounting portion 21 and the thinning portion 22 corresponds to the first annular notch 24, the thickness 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 of ​​the corresponding mounting portion 21. In this way, the impact force can act on the thinning portion 22 with a larger area, so that the thinning portion 22 can be deformed 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 the first annular notch 24 is l, and the depth of the first annular notch 24 is h, wherein 0.4mm≤l≤0.7mm, 0.2mm≤h≤0.28mm. If the width of the first annular notch 24 is too large or too small, it will increase the risk of rupture and have a counterproductive effect. If the depth of the first annular notch 24 is not deep enough, the pressure required for the thinning portion 22 to deform is greater, and the electrolyte will be transferred to the weaker rupture portion 23. If it is too deep, this area will become the place with the greatest risk of rupture, causing the area to rupture prematurely.

[0058] In this embodiment, the depth of the thinning portion 22 is t, 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 the external impact force; if the thinning portion 22 is too deep (greater than 0.5mm), it may cause the battery cover structure itself to be too fragile and easy to break under the action of external force.

[0059] The main function of the thinning portion 22 is to provide an energy absorption area. Under external impact, this area can undergo local deformation or crack expansion, thereby dispersing the impact force and avoiding damage to the rupture portion 23. The design of the thinning portion 22 with a moderate depth can ensure that this area undergoes appropriate deformation during impact and avoids complete failure of the structure. Under external impact, the design of the thinning portion 22 with a depth of 0.2mm to 0.5mm can effectively absorb a certain amount of energy under the impact force, while preventing excessive thinning from causing a decrease in structural strength, thereby ensuring the safety of the overall component.

[0060] The depth of the thinning portion 22 cooperates with the first annular notch 24, the chamfer structure 12 and other designs to form a complete impact absorption mechanism. The depth of the thinning portion 22, the notch design, and the chamfer structure 12 can effectively disperse the impact force through these areas, reducing the impact on key components such as the rupture portion 23. By precisely controlling the depth of the thinning portion 22, the width and depth of the notch, and the synergistic effect of the chamfer structure 12, the impact resistance of the explosion-proof valve 2 when facing the impact of the electrolyte is significantly improved.

[0061] As some preferred embodiments, the chamfer structure 12 of this embodiment has a first chamfer 121 and a second chamfer 122 that are interconnected, the first chamfer 121 is a chamfer or a rounded corner, the second chamfer 122 is a chamfer, 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 thinning portion 22 is deformed and recessed into the mounting hole 11, the first chamfer 121 provides a transition for the thinning portion 22 to deform into the mounting hole 11, reduces stress concentration, and avoids cracks caused by sharp edges. The second chamfer 122 provides enough space for the thinning portion 22 to deform, and provides enough area to disperse the deformation stress of the thinning portion 22.

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

[0064] Preferably, the radius of the first chamfer 121 is 0.1mm-0.3mm, the length of the second chamfer 122 is 0.5mm-1mm, and the angle between the second chamfer 122 and the bottom surface of the top cover 1 is 20°-35°. The first chamfer 121 is an arc-shaped chamfer with a small size, which can effectively alleviate local stress concentration; the larger length of the second chamfer 122 further optimizes the distribution of force and avoids local cracks or ruptures. This design effectively reduces the risk of damage caused by concentrated impact force.

[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 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, and the chamfered structure 12 is used to provide an accommodation 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 the rupture portion 23 in advance.

[0067] As some preferred embodiments, the top cover 1 further includes a lower plastic 3 disposed on the bottom surface thereof, wherein the lower plastic 3 has a through hole 31 at a position corresponding to the explosion-proof valve 2, wherein the area of ​​the through hole 31 is larger than the area of ​​the explosion-proof valve 2, and a blocking plate 32 is fixedly disposed on the through hole 31, wherein 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. By sampling the above structural arrangement, when the battery falls, the kinetic potential energy of the electrolyte will be weakened by the blocking plate 32, thereby reducing the impact energy of the electrolyte, thereby reducing the direct effect of the electrolyte on the rupture portion 23.

[0068] By corresponding the channel 30 and the first annular notch 24, the impact force of the electrolyte can be first applied to the first annular notch 24. In this way, part of the impact force received by the first annular notch 24 acts on the mounting portion 21, and part of it 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] See attached Fig. 9 and 10 As shown, attached Fig. 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 ruptured part will be subjected to a large impact force, and the second annular notch will be severely deformed and there is a risk of rupture. Fig.10The battery cover plate assembly structure of the present application is demonstrated, and it can be clearly seen that the deformation of the second annular notch in the rupture portion is small and there is no cracking. At the first annular notch and the thinned portion, the thinned portion fits toward the chamfered structure, playing a role in buffering and absorbing energy.

[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 installed and providing a thinning portion 22 on the explosion-proof valve 2, the safety risk of falling, rupture and leakage can be fundamentally solved while taking into account the valve opening function of thermal runaway, thereby avoiding the disadvantageous factors of large-scale structural design modification and high cost.

[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 protection scope 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 bottom edge of the mounting hole (11) has a chamfered structure (12); 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) comprises 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 smaller than the thickness of the thinning portion (22). The thickness of the thinning portion (22) is smaller 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) corresponds to the thinning portion (22).

2. The battery cover assembly according to claim 1, characterized in that: The top cover (1) has a mounting groove (13) on its bottom surface, the mounting groove (13) being located on the outer peripheral side of the mounting hole (11), the chamfered structure (12) being located at the junction of the mounting groove (13) and the mounting hole (11), the mounting portion (21) being fixedly arranged in the mounting groove (13), the width of the mounting portion (21) being greater than or equal to the width of the mounting groove (13), and the width of the mounting portion (21) being less than half of 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 2, characterized in that: 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.

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

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

6. The battery cover assembly according to claim 3, characterized in that: The chamfer structure (12) comprises a first chamfer (121) and a second chamfer (122) which are connected to each other, the first chamfer (121) being a chamfered angle or a rounded angle, the second chamfer (122) being a chamfered angle, the second chamfer (122) being located at the bottom edge of the mounting groove (13) and the edge of the mounting hole (11), and the first chamfer (121) being located at the second chamfer (122) and the edge of the mounting hole (11).

7. The battery cover assembly according to claim 6, characterized in that: 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°.

8. The battery cover assembly according to claim 4, characterized in that: 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 greater than the depth and width of the second annular notch (25).

9. The battery cover assembly according to claim 1, characterized in that: The invention also comprises 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 part of the first annular notch (24) is directly opposite to the channel (30).

10. A power battery, characterized in that: Comprising a battery cover assembly as described in any one of claims 1 to 9.

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