Cover plate assembly, battery and battery pack

Abstract

The invention provides a cover plate assembly, a battery and a battery pack. The cover plate assembly comprises a cover plate body used for being connected with the battery shell to seal the inner cavity, the cover plate body comprises a first cover plate part and a second cover plate part, the first cover plate part is provided with a first hole and an anti-explosion nick, the first hole is used for the pole assembly to penetrate through so as to be electrically connected to the electrode assembly, and the anti-explosion nick is arranged on the outer side of the first hole; the second cover plate part is connected between the outer periphery of the first cover plate part and the battery shell, and the second cover plate part comprises a reinforcing structure. The invention aims to solve the problems that the connection strength of the cover plate assembly and the battery shell in the battery is relatively weak, and when the internal air pressure of the battery is increased, the joint of the cover plate assembly and the battery shell is easy to explode to cause thermal runaway of the battery.

Description

Technical Field

[0001] This invention relates to the field of battery technology, specifically to a cover plate assembly, a battery, and a battery pack. Background Technology

[0002] In related technologies, a battery includes a cover assembly, a battery casing, and a core disposed within the battery casing. The cover assembly covers and seals the battery casing. During operation, the battery generates heat, causing its temperature to rise. As the temperature continues to rise, the electrolyte inside the battery decomposes, producing gases. If there is excessive gas inside the battery that cannot escape smoothly, the internal pressure increases, pressing against the cover assembly and causing it to deform. This reduces the connection strength between the battery assembly and the battery casing. If the pressure continues to increase, the connection between the cover assembly and the battery casing may burst. If the battery is not de-energized, it is prone to explosion, exacerbating thermal runaway. Summary of the Invention

[0003] The embodiments of the present invention provide a cover plate assembly, a battery, and a battery pack, which aim to solve the problem that the connection strength between the cover plate assembly and the battery casing is weak, and the connection between the cover plate assembly and the battery casing is prone to bursting when the internal gas pressure of the battery increases, resulting in thermal runaway of the battery.

[0004] In a first aspect, embodiments of the present invention provide a cover plate assembly applied to a battery, the battery including a battery housing having an inner cavity, a terminal assembly, and an electrode assembly installed within the inner cavity, wherein the cover plate assembly includes a cover plate body for connecting the battery housing to seal the inner cavity, the cover plate body comprising:

[0005] The first cover plate has a first hole and an explosion-proof notch. The first hole allows the electrode post assembly to pass through and be electrically connected to the electrode assembly. The explosion-proof notch is located on the outside of the first hole.

[0006] A second cover plate is connected between the outer periphery of the first cover plate and the battery casing, and the second cover plate includes a reinforcing structure.

[0007] In one embodiment, the diameter of the circle containing the outer contour of the battery casing projected along its axial direction is D1, the diameter of the circle containing the center line of the orthographic projection of the explosion-proof marking on the horizontal plane is D2, and the diameter of the circle containing the center line of the orthographic projection of the reinforcing structure on the horizontal plane is D3, where D2 = aD1, D3 = bD1, a is a first coefficient, 0.4 ≤ a ≤ 0.75, and b is a second coefficient, 0.5 ≤ b ≤ 0.8.

[0008] In one embodiment, the thickness of the cover plate body is H, where D3-D2=2cH, c is a third coefficient, and c>3.

[0009] In one embodiment, the reinforcing structure includes a bending structure.

[0010] In one embodiment, the bending structure includes a recess that is configured to be recessed into the inner cavity on one side of the second cover plate portion.

[0011] In one embodiment, the electrode assembly includes a first electrode and a second electrode, the first electrode and the second electrode having opposite polarities;

[0012] The recessed portion is electrically connected to the first electrode, and the electrode post assembly is electrically connected to the second electrode.

[0013] In one embodiment, the battery includes a first current collector;

[0014] The recessed portion is provided with a welding plate, which is used to weld to the first current collector to electrically connect to the first electrode through the first current collector;

[0015] The thickness of the welding plate is less than the thickness of the area of ​​the second cover plate where the recess is not provided.

[0016] In one embodiment, the thickness of the area of ​​the second cover plate where the recess is not provided is H, the thickness of the welding plate is H31, and the thickness of the first current collector is H41, wherein H31 = fH, H41 = gH31, where f is the sixth coefficient, 0.5 ≤ f ≤ 0.7, and g is the seventh coefficient, 0.5 ≤ g ≤ 1.2.

[0017] In one embodiment, the recess is provided with a welding plate, which is used to electrically connect to the first electrode sheet;

[0018] Wherein, the thickness of the welding plate is less than the thickness of the area of ​​the second cover plate where the recess is not provided;

[0019] The thickness of the welding plate is H31, the thickness of the area of ​​the first cover plate without the explosion-proof marking is H6, and the marking depth of the explosion-proof marking is H32, where (H6-H32)=pH31, p is the eleventh coefficient, 0.14≤p≤0.6.

[0020] In one embodiment, the thickness of the area of ​​the second cover plate without the recess is H, the thickness of the area of ​​the first cover plate without the explosion-proof marking is H6, the marking depth of the explosion-proof marking is H32, (H6-H32)=qH, q is the twelfth coefficient, 0.1≤q≤0.3.

[0021] In one embodiment, the thickness of the area of ​​the second cover plate where the recess is not provided is H, the width of the recess is H1, and the depth of the recess is H2, wherein H1 = dH, H2 = eH, d is the fourth coefficient, 2.5 ≤ d ≤ 5, and e is the fifth coefficient, 1.5 ≤ e ≤ 3.5.

[0022] In one embodiment, the cover plate body has a normal state, and in the normal state, the first cover plate portion is further provided with a groove, the groove having a bottom wall and an inner side wall connected to the bottom wall, and the explosion-proof groove is provided on the bottom wall.

[0023] In one embodiment, the thickness of the area of ​​the first cover plate without the groove is H3, the groove width is H4, the groove depth is H5, and the thickness of the area of ​​the bottom wall without the explosion-proof marking is H6, where H4 = kH3, H5 = mH3, H6 = nH3, k is the eighth coefficient, 2 ≤ k ≤ 5, m is the ninth coefficient, 1 ≤ m ≤ 2, and n is the tenth coefficient, 0.5 ≤ n ≤ 1.

[0024] In one embodiment, the inner sidewall is inclined relative to the bottom wall, and the included angle between the inner sidewall and the bottom wall is α, wherein 55°≤α≤135°.

[0025] In one embodiment, the groove protrudes toward the inner cavity, and the cover plate body also has an abnormal state, wherein the first cover plate portion of the cover plate body in the abnormal state is flatter than the first cover plate portion of the cover plate body in the normal state.

[0026] In one embodiment, the first cover plate includes a first connecting plate and a second connecting plate connected to the outer periphery of the first connecting plate, and the explosion-proof groove is provided on the second connecting plate;

[0027] The cover plate assembly further includes an insulating element disposed between the pole assembly and the first connecting plate, and abutting against the second connecting plate.

[0028] In one embodiment, the insulating member includes a first insulating portion and a second insulating portion, and the first connecting plate is located between the first insulating portion and the second insulating portion;

[0029] The second insulating part is located on the side of the first connecting plate near the inner cavity, the second connecting plate is recessed towards the inner cavity, and the end of the second insulating part opposite to the pole assembly abuts against the side of the second connecting plate.

[0030] In one embodiment, the explosion-proof groove is provided around the first hole.

[0031] Secondly, embodiments of the present invention provide a battery, comprising:

[0032] Battery casing with an inner cavity;

[0033] Electrode assemblies are installed in the inner cavity;

[0034] The electrode assembly is electrically connected to the electrode assembly; and,

[0035] The aforementioned cover assembly connects to the battery housing and seals the inner cavity.

[0036] In one embodiment, when the air pressure inside the cavity is a first air pressure, the pole assembly is disconnected from the electrode assembly;

[0037] When the air pressure inside the inner cavity is the second air pressure, the cover plate assembly ruptures at the explosion-proof notch;

[0038] Wherein, the first air pressure is P1, the second air pressure is P2, 1.2Mpa≤P1≤1.8Mpa, P2>1.8Mpa.

[0039] Thirdly, embodiments of the present invention provide a battery pack including the battery described above.

[0040] The beneficial effects of the embodiments of the present invention are as follows:

[0041] In this invention, a reinforcing structure is provided on the second cover plate to enhance its resistance to deformation and improve the connection strength between the second cover plate and the battery casing. This solves the problem in related technologies where increased internal battery pressure causes the cover plate assembly to deform, reducing the connection strength between the cover plate assembly and the battery casing, and leading to the cover plate assembly exploding at the connection point when the pressure continues to increase. Simultaneously, the first cover plate has explosion-proof grooves. When the internal battery pressure increases, the cover plate breaks at the explosion-proof grooves, releasing the internal gas and achieving pressure relief. This prevents the second cover plate from exploding at the battery casing, thus avoiding battery ignition or thermal runaway. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the structure of an embodiment of the battery provided by the present invention;

[0044] Figure 2 yes Figure 1A schematic diagram of the structure of a battery under the first atmospheric pressure;

[0045] Figure 3 yes Figure 1 A schematic diagram of another embodiment of the battery under the first atmospheric pressure;

[0046] Figure 4 yes Figure 1 A schematic diagram of the structure of a battery under a second atmospheric pressure;

[0047] Figure 5 This is a schematic diagram of a structure of an embodiment of the cover plate assembly provided by the present invention;

[0048] Figure 6 yes Figure 5 Schematic diagram of the structure of the middle cover plate body;

[0049] Figure 7 yes Figure 6 Enlarged diagram of A in the middle;

[0050] Figure 8 yes Figure 6 Enlarged diagram of B in the diagram;

[0051] Figure 9 yes Figure 6 Enlarged diagram of C in the middle;

[0052] Figure 10 yes Figure 5 Full sectional view of the middle cover plate assembly.

[0053] Explanation of icon numbers

[0054] label name label name 100 Cover plate assembly 114 First insulating part 101 Cover plate body 115 Second insulation section 102 First cover plate section 116 Side panel 103 First hole 117 First bend connection part 104 Explosion-proof markings 118 Second bend connection part 105 Second cover plate section 1000 Battery 106 Depression 200 Battery casing 107 Welding plate 201 inner cavity 108 groove 300 Electrode assembly 109 bottom wall 301 First Pole Film 110 inner wall 302 Second pole plate 111 First connecting plate 400 pole piece 112 Second connecting plate 500 First collection device 113 Insulating components 600 Second flow component Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present invention and are not intended to limit the present invention. In the present invention, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0056] In related technologies, a battery includes a cover assembly, a battery casing, and a core disposed within the battery casing. The cover assembly covers and seals the battery casing. During operation, the battery generates heat, causing its temperature to rise. As the temperature continues to rise, the electrolyte inside the battery decomposes, producing gases. If there is excessive gas inside the battery that cannot escape smoothly, the internal pressure increases, pressing against the cover assembly and causing it to deform. This reduces the connection strength between the battery assembly and the battery casing. If the pressure continues to increase, the connection between the cover assembly and the battery casing may burst. If the battery is not de-energized, it is prone to explosion, exacerbating thermal runaway.

[0057] In view of this, the present invention proposes a battery 1000, Figures 1 to 4 This is a schematic diagram of a structure of an embodiment of the battery 1000 provided by the present invention. The battery 1000 provided by the present invention has a simple structure. When the internal gas pressure of the battery 1000 is too high, it will break, thereby avoiding the phenomenon of explosion or thermal runaway. The battery 1000 will be described in detail below with reference to the main drawings.

[0058] Please see Figure 1 This invention proposes a battery 1000, which includes a battery casing 200 having an inner cavity 201, an electrode assembly 300 installed in the inner cavity 201, and a terminal post assembly 400. The cover plate assembly 100 includes a cover plate body 101 for connecting the battery casing 200 to seal the inner cavity 201. The cover plate body 101 includes a first cover plate portion 102 and a second cover plate portion 105. The first cover plate portion 102 is provided with a first hole 103 and an explosion-proof groove 104. The explosion-proof groove 104 can be integrally formed into the first cover plate portion 102, or it can be separately connected to the first cover plate portion 102 through an explosion-proof valve plate. The first hole 103 is used for the terminal post assembly 400 to pass through and be electrically connected to the electrode assembly 300. The explosion-proof groove 104 is provided on the outside of the first hole 103. The second cover plate portion 105 is connected between the outer periphery of the first cover plate portion 102 and the battery casing 200. The second cover plate portion 105 includes a reinforcing structure.

[0059] In this embodiment, the electrode assembly 300 includes a first electrode 301 wound together, a separator, and a second electrode 302, wherein the first electrode 301 and the second electrode 302 have opposite polarities. The battery 1000 also includes two first current collectors 500 and two second current collectors 600. The two first current collectors 500 are located at both ends of the electrode assembly 300 and are electrically connected to the first electrode 301. The two second current collectors 600 are located at both ends of the electrode assembly 300. That is, both ends of the electrode assembly 300 are provided with first current collectors 500 and second current collectors 600, thereby improving the current collection capacity of the battery 1000.

[0060] Furthermore, the first electrode 301 has first tabs of the same polarity at both ends, and two first current collectors 500 are respectively connected to the two first tabs. Specifically, the two first current collectors 500 are respectively welded to their corresponding first tabs. Similarly, the second electrode 302 has second tabs of the same polarity at both ends, and two second current collectors 600 are respectively connected to the two second tabs. Specifically, the two second current collectors 600 are respectively welded to their corresponding second tabs.

[0061] It should be noted that the first cover plate portion 102 and the second cover plate portion 105 are integrally formed. In this embodiment, the second cover plate portion 105 can be welded to the battery casing 200. The cover plate body 101 has a disc-shaped structure. In some embodiments, the cover plate body 101 can be made of steel, such as SPCC material, stainless steel materials SUS410, SUS306, SUS316, SUS430, SUS444, etc. When SPCC material is used, nickel can be plated on both sides of the cover plate body 101, with a plating thickness of 0.3μm to 8μm. The plating thickness on both sides of the cover plate body 101 can be the same or different. In other embodiments, the cover plate body 101 can be made of aluminum or copper. Aluminum and copper have lower resistance, which can reduce the resistance of the battery 1000.

[0062] It should be noted that the first electrode 301 and the second electrode 302 have opposite polarities; that is, one of the first electrode 301 and the second electrode 302 is a positive electrode, and the other is a negative electrode. In this embodiment, the first electrode 301 is a negative electrode, and the second electrode 302 is a positive electrode. Therefore, the cover plate assembly 100 serves as the negative output terminal, and the electrode post assembly 400 serves as the positive output terminal.

[0063] Furthermore, the first electrode 301 and the second electrode 302 include a coated area with active material and an uncoated area without active material. The first tab and the second tab can be integrally formed as at least a portion of the uncoated area. In other embodiments, the first tab can be separately soldered to the first electrode 301, and the second tab can be separately soldered to the second electrode 302. Specifically, the choice can be made according to actual needs.

[0064] In this embodiment, the first current collector 500 is an annular component, and the second current collector 600 is a circular component. The second current collector 600 is disposed within the annulus of the first current collector 500, and the first current collector 500 and the second current collector 600 do not contact each other. It should be noted that the centers of the first current collector 500 and the second current collector 600 may or may not coincide, depending on the actual situation and the actual layout of the structure within the battery 1000. When the centers of the first current collector 500 and the second current collector 600 do not coincide, they cannot contact each other.

[0065] Under normal operating conditions, battery 1000 also produces some gas, and its internal pressure can reach 1.2 MPa. When the internal pressure of battery 1000 is below 1.2 MPa, battery 1000 can operate normally. Generally, before battery 1000 triggers thermal runaway, the temperature continuously rises. During this time, the electrolyte inside battery 1000 decomposes with the increasing temperature, producing a large amount of gas. This increases the internal pressure of battery 1000, and if not released in time, battery 1000 may explode or experience thermal runaway. In this embodiment, to improve the safety performance of battery 1000, when the internal pressure of battery 1000 changes, the power must be disconnected first, and then the pressure released. For details, please refer to... Figure 2 or Figure 3 When the air pressure inside the inner cavity 201 is the first air pressure, the terminal assembly 400 and the electrode assembly 300 are disconnected. At this first air pressure, the cover assembly 100 will not break. The terminal assembly 400 and the electrode assembly 300 disconnect first, and the battery 1000 is in a power-off state. After the battery 1000 is powered off, it no longer operates, and the temperature of the battery 1000 will not continue to rise, thus reducing the internal pressure of the battery 1000 and improving its safety. Furthermore, the first air pressure is P1, where 1.2 MPa ≤ P1 ≤ 1.8 MPa. More specifically, P1 may be set to 1.2MPa, 1.25MPa, 1.26MPa, 1.28MPa, 1.31MPa, 1.33MPa, 1.4MPa, 1.43MPa, 1.48MPa, 1.5MPa, 1.55MPa, 1.58MPa, 1.62MPa, 1.66MPa, 1.77MPa, 1.79MPa, 1.8MPa, or other unlisted values.

[0066] It should be noted that there are multiple ways in which the pole post assembly 400 and the electrode assembly 300 can be disconnected, and in actual applications, multiple forms may occur.

[0067] Format 1: Please refer to Figure 2 A second current collector 600 is provided between the terminal assembly 400 and the electrode assembly 300. The terminal assembly 400 and the second current collector 600 are welded together, and the second current collector 600 is welded together with the second tab. When the internal pressure of the battery 1000 exceeds 1.2 MPa, the gas inside the battery 1000 pushes the terminal assembly 400 to move away from the electrode assembly 300. As the pressure increases, the terminal assembly 400 and the second current collector 600 are disconnected, and the battery 1000 is de-energized.

[0068] Form 2: Please refer to Figure 3A second current collector 600 is provided between the terminal assembly 400 and the electrode assembly 300. The terminal assembly 400 and the second current collector 600 are welded together, and the second current collector 600 is welded together with the second tab. When the internal pressure of the battery 1000 exceeds 1.2 MPa, the gas inside the battery 1000 pushes the terminal assembly 400 to move away from the electrode assembly 300. As the pressure increases, the second current collector 600 is disconnected from the second tab, and the battery 1000 is de-energized.

[0069] Please see Figure 4 When the battery 1000 reaches the end of its thermal runaway phase, the internal pressure of the battery 1000 rises to a certain level, requiring the explosion-proof valve to open and release the combustible material inside the battery 1000 to prevent the battery 1000 from exploding. In this embodiment, when the internal pressure of the battery 1000 exceeds 1.8 MPa, the cover assembly 100 breaks at the explosion-proof notch 104, allowing the gas inside the battery 1000 to escape. Specifically, when the pressure inside the inner cavity 201 is a second pressure, the cover assembly 100 breaks at the explosion-proof notch 104, where the second pressure is P2, and P2 > 1.8 MPa. More specifically, P2 may be set to 1.82 MPa, 1.85 MPa, 1.91 MPa, 1.98 MPa, 2.1 MPa, 2.21 MPa, 2.24 MPa, 2.28 MPa, 2.4 MPa, 2.45 MPa, 2.55 MPa, or other unlisted values.

[0070] The present invention also proposes a cover plate assembly 100, which is applied to a battery 1000. Figures 5-10 This is a schematic diagram of a structure of an embodiment of the cover plate assembly 100 provided by the present invention.

[0071] Specifically, please refer to Figure 5 and Figure 6 The cover plate assembly 100 includes a cover plate body 101 for connecting the battery housing 200 to seal the inner cavity 201; the cover plate body 101 includes a first cover plate portion 102 and a second cover plate portion 105, the first cover plate portion 102 is provided with a first hole 103 and an explosion-proof groove 104, the first hole 103 is for the electrode post assembly 400 to pass through and be electrically connected to the electrode assembly 300, and the explosion-proof groove 104 is provided on the outside of the first hole 103; the second cover plate portion 105 is connected between the outer periphery of the first cover plate portion 102 and the battery housing 200, and the second cover plate portion 105 includes a reinforcing structure.

[0072] In the technical solution of this invention, a reinforcing structure is provided on the second cover plate portion 105. The reinforcing structure is used to enhance the deformation resistance of the second cover plate portion 105 and improve the connection strength between the second cover plate portion 105 and the battery casing 200. This solves the problem in related technologies where increased internal pressure of the battery 100 causes the cover plate assembly 100 to deform, reducing the connection strength between the cover plate assembly 100 and the battery casing 200, and causing the connection to explode when the pressure continues to increase. Simultaneously, the first cover plate portion 102 is provided with explosion-proof grooves 104. When the internal gas pressure of the battery 1000 increases, the cover plate body 101 breaks at the explosion-proof grooves 104, releasing the internal gas of the battery 1000 and achieving pressure relief. This prevents the second cover plate portion 105 from exploding at the battery casing 200, thus avoiding battery 1000 ignition or thermal runaway.

[0073] It should be noted that in the above embodiments, the explosion-proof groove 104 is integrally disposed on the first cover portion 102 of the cover body 101. In some other embodiments, the battery 1000 also includes an explosion-proof sheet separately disposed from the first cover portion 102, and the explosion-proof groove 104 may also be disposed on the explosion-proof sheet. The specific structure and position of the explosion-proof sheet can be referred to conventional settings in the art, and will not be described in detail here. The specific selection can be made according to the actual situation or actual needs.

[0074] In some embodiments, please refer to 2 and Figure 6The diameter of the circle containing the outer contour of the battery casing 200 projected along its axial direction is D1, and the diameter of the circle containing the center line of the orthographic projection of the explosion-proof notch 104 on the horizontal plane is D2, where D2 = aD1, a is a first coefficient, 0.4 ≤ a ≤ 0.75. Specifically, the explosion-proof notch 104 is provided on the first cover plate portion 102, and the diameter of the explosion-proof notch 104 should not be too large or too small. When a is less than 0.4, the diameter of the explosion-proof notch 104 is too small, causing the explosion-proof notch 104 to shift towards the direction of the first hole 103. A first insulating member 113 is provided between the cover plate assembly 100 and the terminal assembly 400. When the diameter of the explosion-proof notch 104 is too small, the position of the explosion-proof notch 104 will coincide with the position of the first insulating member 113, and the first insulating member 113 will protect the explosion-proof notch 104, preventing the explosion-proof notch 104 from breaking. When 'a' is greater than 0.75, the explosion-proof notch 104 shifts towards the reinforcing structure. The reinforcing structure provides some protection for the explosion-proof notch 104, requiring greater pressure to break it. This makes the battery 1000 prone to thermal runaway. In some embodiments, the diameter of the circle containing the center line of the orthographic projection of the explosion-proof notch 104 on the horizontal plane can be 0.4D1, 0.45D1, 0.5D1, 0.55D1, 0.6D1, 0.65D1, 0.7D1, 0.75D1, or other unlisted values.

[0075] Further, in some embodiments, the diameter of the circle containing the center line of the orthographic projection of the explosion-proof notch 104 on the horizontal plane is 18–24 mm. When D2 is 18 mm, D1 can be 45 mm, 40 mm, 36 mm, 32.73 mm, 30 mm, 27.69 mm, 25.71 mm, or 24 mm. When D2 is 21 mm, D1 can be 52.5 mm, 46.67 mm, 42 mm, 38.18 mm, 35 mm, 32.31 mm, 30 mm, 28 mm, or other unlisted values. When D2 is 24 mm, D1 can be 60 mm, 53.33 mm, 48 mm, 43.64 mm, 40 mm, 36.92 mm, 34.29 mm, 32 mm, or other unlisted values.

[0076] Please continue reading. Figure 2 and Figure 6The diameter of the circle containing the center line of the orthographic projection of the reinforcing structure on the horizontal plane is D3, where D3 = bD1, and b is a second coefficient, 0.5 ≤ b ≤ 0.8. It should be noted that when b is less than 0.5, the reinforcing structure shifts towards the explosion-proof notch 104, meaning the distance between the reinforcing structure and the explosion-proof notch 104 shortens. The reinforcing structure provides some protection for the explosion-proof notch 104. However, when the internal pressure of the battery 1000 is too high, the explosion-proof notch 104 requires a greater force to break, increasing the risk of battery 1000 explosion or thermal runaway. When b is greater than 0.8, the reinforcing structure shifts away from the explosion-proof notch 104, increasing the longitudinal dimension of the second cover plate portion 105 and the longitudinal dimension of the cover plate body 101, thus increasing the space occupied. In some embodiments, the diameter of the circle containing the center line of the orthographic projection of the reinforcing structure onto the horizontal plane is 0.5D1, 0.55D1, 0.58D1, 0.6D1, 0.62D1, 0.65D1, 0.68D1, 0.7D1, 0.75D1, 0.77D1, 0.8D1, or other unlisted values.

[0077] Furthermore, in some embodiments, when D1 is 24mm, D3 can be 12mm, 13.2mm, 13.92mm, 14.4mm, 14.88mm, 15.6mm, 16.32mm, 16.8mm, 18mm, 18.48mm, 19.2mm, or other unlisted values. When D1 is 40mm, D3 can be 20mm, 22mm, 23.2mm, 24mm, 24.8mm, 26mm, 27.2mm, 28mm, 30mm, 30.8mm, 32mm, or other unlisted values. When D1 is 60mm, D3 can be 30mm, 33mm, 34.8mm, 36mm, 37.2mm, 39mm, 40.8mm, 42mm, 45mm, 46.2mm, 48mm or other unlisted values.

[0078] In some embodiments, the thickness of the cover body 101 is 0.4 to 1 mm. More specifically, the thickness of the cover body 101 can be 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1 mm, or other unlisted values. Please refer to [link to relevant documentation]. Figure 1The thickness of the cover plate body 101 is H, where D3-D2=2cH, and c is a third coefficient, c>3. It should be noted that while the diameters of the circles containing the center lines of the orthographic projections of the cover plate body 101, the reinforcing structure, and the explosion-proof notch 104 on the horizontal plane must satisfy their respective proportional relationships, D3-D2=2cH must also be satisfied. This arrangement allows for a reasonable layout of the explosion-proof notch 104 and the reinforcing structure, improving the space utilization of the battery 1000.

[0079] Specifically, the specific type of the reinforcing structure is not limited, as long as it can improve the deformation resistance of the second cover plate 105, causing the cover plate body 101 to break at the indentation when the internal gas pressure of the battery 1000 increases. In some embodiments, the reinforcing structure is a bent structure. In other embodiments, the reinforcing structure is a boss structure.

[0080] Further, please refer to Figure 6 and Figure 8 In this embodiment, the reinforcing structure is a bending structure, which includes a recessed portion 106. The recessed portion 106 is electrically connected to the first electrode 301, making the cover plate body 101 serve as one output electrode. The electrode assembly 400 is electrically connected to the second electrode 302, making the electrode assembly serve as the other output electrode, thereby achieving same-side output. Simultaneously, the recessed portion 106 can disperse the pressure on the cover plate body 101, improving its resistance to deformation. When the internal air pressure of the battery 1000 increases, the recessed portion 106 can prevent the cover plate body 101 from bearing greater forces, thus improving the service life of the battery 1000.

[0081] Furthermore, the direction of the recess 106 is not limited, as long as it can improve the deformation resistance of the cover plate body 101. In some embodiments, the recess 106 is configured to protrude from one side of the second cover plate portion 105 away from the inner cavity 201. In another embodiment, the recess 106 is configured to recess into the inner cavity 201 from one side of the second cover plate portion 105. It should be noted that the recessed configuration is better than the protruding configuration. On the one hand, the recess into the inner cavity 201 can save space, and on the other hand, the recess into the inner cavity 201 facilitates the connection between the second cover plate portion 105 and the electrode assembly 300.

[0082] It should be noted that the connection method between the recess 106 and the first electrode 301 is not limited, nor is the connection method between the electrode assembly 400 and the second electrode 302. For example, in one embodiment, to shorten the current collection path, the recess 106 is directly connected to the first electrode 301, and the electrode assembly 400 is directly connected to the second electrode 302. In another embodiment, please refer to... Figure 1To ensure connection strength and improve the stability of battery 1000, electrode assembly 300 includes a first current collector 500 and a second current collector 600. The first current collector 500 is disposed between the first electrode 301 and the second cover plate portion 105, and the first current collector 500 is electrically connected to the first electrode 301 and the second cover plate portion 105 at the recess 106. At the same time, the second current collector 600 is disposed between the second electrode 302 and the electrode post assembly 400, and the second current collector 600 is electrically connected to both the second electrode 302 and the electrode post assembly 400.

[0083] Furthermore, to ensure connection strength, the first current collector is welded to the first electrode 301 and the second cover plate 105 at the recess 106, and the second current collector 600 is welded to the second electrode 302 and the electrode assembly 400. It should be noted that the first electrode 301 has first tabs at both ends, and the second electrode 302 has second tabs at both ends. Here, "welding to the first electrode 301" means welding to the first tabs on the first electrode 301; "welding to the second electrode 302" means welding to the second tabs on the second electrode 302.

[0084] Please refer to the figure. Figure 6 and Figure 8 The second cover portion 105 includes a welding plate 107 and a side plate 116 forming a recess. In some embodiments, the welding plate 107 is configured to be welded to the first current collector 500. In other embodiments, the side plate 116 is configured to be welded to the first current collector 500.

[0085] It should be noted that the method of forming the recess 106 is not limited. In this embodiment, the recess 106 includes a first groove, which is formed by stamping. Specifically, the cover plate body 101 is placed on a stamping machine, the punch is aligned with the second cover plate portion 105, and the first groove is stamped on the second cover plate portion 105. During the stamping process, due to the stamping force, the thickness of the bottom of the first groove (i.e., the welding plate 107) is less than the thickness of the area of ​​the second cover plate portion 105 where the recess 106 is not provided.

[0086] Furthermore, considering the difficulty of welding, in this embodiment, the welding plate 107 is configured to be welded to the first current collector 500. Specifically, the thickness of the welding plate 107 is less than the thickness of the area of ​​the second cover plate portion 105 where the recess 106 is not provided. This configuration reduces the thickness of the welding plate 107, allowing the welding laser to penetrate the welding plate 107 more easily during the welding process, reducing the difficulty of welding, avoiding situations such as incomplete welds, and improving the connection strength between the recess 106 and the first current collector 500.

[0087] Please see Figure 8In some embodiments, the thickness of the area of ​​the second cover plate 105 without the recess 106 is H, and the thickness of the welding plate 107 is H31, where H31 = fH, f is a sixth coefficient, and 0.5 ≤ f ≤ 0.7. It should be noted that when f is less than 0.5, the thickness of the welding plate 107 is relatively thin, and the connection strength between the welding plate 107 and the first current collector 500 is low. When the internal gas pressure of the battery 1000 increases, the second cover plate 105 is prone to breakage at the recess 106. When f is greater than 0.7, the thickness of the welding plate 107 is relatively thick, increasing the difficulty of welding. Specifically, the value of H ranges from 0.4 to 1 mm. More specifically, the thickness of the area of ​​the second cover plate portion 105 where the recess 106 is not provided can be 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm or other unlisted values.

[0088] In some embodiments, H31 (i.e., the thickness of the welding plate 107) is 0.5H, 0.52H, 0.54H, 0.55H, 0.56H, 0.58H3, 0.6H, 0.62H, 0.64H, 0.65H, 0.66H, 0.68H, 0.7H, or other unlisted values. Specifically, when H is 0.4mm, H31 can be 0.2mm, 0.208mm, 0.216mm, 0.22mm, 0.224mm, 0.232mm, 0.24mm, 0.248mm, 0.256mm, 0.26mm, 0.264mm, 0.272mm, 0.28mm, or other unlisted values. When H is 0.6 mm, H31 can be 0.3 mm, 0.312 mm, 0.324 mm, 0.33 mm, 0.336 mm, 0.348 mm, 0.36 mm, 0.372 mm, 0.384 mm, 0.39 mm, 0.396 mm, 0.408 mm, 0.42 mm, or other unlisted values. When H is 1 mm, the thickness of H31 is 0.5 mm, 0.52 mm, 0.54 mm, 0.55 mm, 0.56 mm, 0.58 mm, 0.6 mm, 0.62 mm, 0.64 mm, 0.65 mm, 0.66 mm, 0.68 mm, 0.7 mm, or other unlisted values.

[0089] Please continue reading. Figure 8The thickness of the first current collector 500 is H41, where H41 = gH31, and g is the seventh coefficient, 0.5 ≤ g ≤ 1.2. It should be noted that when g is less than 0.5, the thickness of the first current collector 500 is relatively thin, making it prone to ablation during normal operation of the battery 1000. Furthermore, the connection strength between the first current collector 500 and the second cover plate 105 and the electrode assembly 300 is also relatively low, making it prone to detachment. When g is greater than 1.2, the thickness of the second current collector 600 is relatively thick, increasing the space occupied and increasing the resistance. For example, the thickness of the first current collector 500 is 0.5H31, 0.6H31, 0.7H31, 0.8H31, 0.9H31, 1.0H31, or 1.1H31. When H31 is 0.2mm, H41 can be 0.1mm, 0.12mm, 0.14mm, 0.16mm, 0.18mm, 0.2mm, 0.22mm, 0.24mm, or other unlisted values. When H31 is 0.5mm, H41 can be 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, or other unlisted values. When H31 is 0.7mm, H41 can be 0.35mm, 0.42mm, 0.49mm, 0.56mm, 0.63mm, 0.7mm, 0.77mm, 0.84mm, or other unlisted values.

[0090] In some embodiments, please refer to Figure 9 The thickness of side plate 116 is H42, where c1H42 = H31, and c1 is the thirteenth coefficient, 0.3 ≤ c1 ≤ 0.6. It should be noted that when c1 is less than 0.3, the thickness of side plate 116 is relatively thin, making it prone to breakage during use. When c1 is greater than 0.6, the thickness of side plate 116 increases, occupying more space. When H31 is 0.2mm, H42 can be 0.67mm, 0.571mm, 0.5mm, 0.44mm, 0.4mm, 0.364mm, 0.34mm, or other unlisted values. When H31 is 0.5mm, H42 can be 1.67mm, 1.43mm, 1.25mm, 1.11mm, 1mm, 0.91mm, 0.84mm, or other unlisted values. When H31 is 0.7mm, H42 can be 2.34mm, 2mm, 1.75mm, 1.56mm, 1.4mm, 1.273mm, 1.167mm or other unlisted values.

[0091] Please see Figure 9The recess 106 includes a first bent connecting portion 117 and a second bent connecting portion 118. The first bent connecting portion 117 connects the side plate 116 and the welding plate 107, and the second bent connecting portion 118 connects the side plate 116 and the area of ​​the cover plate body 101 where the recess 106 is not provided. It should be noted that in the above embodiment, H31 refers to the dimension of the welding plate 107 where the thickness is uniform, excluding the dimension of the bending point. Similarly, H42 also refers to the dimension of the side plate 116 where the thickness is uniform, excluding the dimension of the bending point. It should be noted that the purpose of providing the first bent connecting portion 117 and the second bent connecting portion 118 is to disperse the force on the recess 106, avoid force concentration, and improve the deformation resistance of the cover plate body 101.

[0092] For further information, please refer to [link / reference]. Figure 9 The radius of curvature of the first bent connecting portion 117 is R1, where R1 = m1H, m1 is the fourteenth coefficient, and 0.8 ≤ m1 ≤ 2. It should be noted that when m1 is less than 0.8, the radius of curvature of the first bent connecting portion 117 is small, failing to achieve the effect of dispersing force. When m1 is greater than 2, the radius of curvature of the first bent connecting portion 117 is large, resulting in an increase in the overall size of the cover plate body 101 and a larger space occupation. For example, R1 can be 0.8H, 0.82H, 0.84H, 0.85H, 0.88H, 0.9H, 0.92H, 0.94H, 0.95H, 0.96H, 1H, 1.2H, 1.4H, 1.5H, 1.6H, 1.8H, 2H, or other unlisted values. When H is 0.4 mm, R1 can be 0.32 mm, 0.328 mm, 0.336 mm, 0.34 mm, 0.352 mm, 0.36 mm, 0.368 mm, 0.376 mm, 0.38 mm, 0.384 mm, 0.4 mm, 0.48 mm, 0.56 mm, 0.6 mm, 0.64 mm, 0.72 mm, 0.8 mm, or other unlisted values. When H is 0.6 mm, R1 is 0.48 mm, 0.492 mm, 0.504 mm, 0.51 mm, 0.528 mm, 0.54 mm, 0.552 mm, 0.564 mm, 0.57 mm, 0.576 mm, 0.588 mm, 0.6 mm, 0.66 mm, 0.72 mm, 0.84 mm, 0.9 mm, 0.96 mm, 1.08 mm, 1.2 mm, or other unlisted values. When H is 1 mm, R1 is 0.8 mm, 0.82 mm, 0.84 mm, 0.85 mm, 0.88 mm, 0.9 mm, 0.92 mm, 0.94 mm, 0.95 mm, 0.96 mm, 1 mm, 1.2 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.8 mm, 2 mm, or other unlisted values.

[0093] Please continue reading. Figure 9 The radius of curvature of the second bent connecting portion 118 is R2, where R2 = n1H3, n1 is the fifteenth coefficient, and 0.1 ≤ n1 ≤ 1. When n1 is less than 0.1, the radius of curvature of the second bent connecting portion 118 is small, and it cannot achieve the effect of dispersing the force. When n1 is greater than 1, the radius of curvature of the second bent connecting portion 118 is large, resulting in an increase in the overall size of the cover plate body 101 and an increase in the space occupied. For example, the radius of curvature of the second bent connecting portion 118 is 0.1H, 0.2H, 0.3H, 0.4H, 0.5H, 0.6H, 0.7H, 0.8H, 0.9H, 1H, or other unlisted values. When H is 0.4 mm, R² is 0.04 mm, 0.08 mm, 0.12 mm, 0.16 mm, 0.2 mm, 0.24 mm, 0.28 mm, 0.32 mm, 0.36 mm, 0.4 mm, or other unlisted values. When H is 0.6 mm, R² is 0.06 mm, 0.12 mm, 0.18 mm, 0.24 mm, 0.3 mm, 0.36 mm, 0.42 mm, 0.48 mm, 0.56 mm, 0.6 mm, or other unlisted values. When H is 1 mm, R² is 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, or other unlisted values.

[0094] Furthermore, in some embodiments, R1 = p1R2, where p1 is the sixteenth coefficient, and 0.15 ≤ p1 ≤ 0.5. Specifically, for example, when H is 0.4 mm, R1 is 0.32 mm, and R2 is 0.16 mm, then p is 0.5, which meets the requirements of the above formula.

[0095] In some embodiments, the thickness of the first bent connection portion 117 gradually decreases along the direction from the side plate 116 to the welding plate 107. This arrangement makes the connection between the side plate 116 and the area of ​​the second cover plate portion 105 where the recess 106 is not provided smoother.

[0096] Please continue reading. Figure 8The width of the recess 106 is H1, where H1 = dH, d is a fourth coefficient, and 2.5 ≤ d ≤ 5. It should be noted that the width of the recess 106 here refers to the distance between the two side plates 116 in the cross-section of the recess 106 (i.e., excluding the bending area). When d is less than 2.5, the overall width of the recess 106 is relatively small, the width of the welding plate 107 is correspondingly reduced, the welding area between the welding plate 107 and the first current collector 500 is reduced, and the welding strength is decreased. When d is greater than 5, the overall width of the recess 106 increases, and the space occupied increases. For example, H1 can be 2.5H, 2.6H, 2.8H, 3H, 3.2H, 3.5H, 3.8H, 4H, 4.2H, 4.5H, 4.8H, 5H, or other unlisted values. When H is 0.4 mm, H1 can be 1 mm, 1.04 mm, 1.12 mm, 1.2 mm, 1.28 mm, 1.4 mm, 1.52 mm, 1.6 mm, 1.68 mm, 1.8 mm, 1.92 mm, 2 mm, or other unlisted values. When H is 0.6 mm, H1 can be 1.5 mm, 1.56 mm, 1.68 mm, 1.8 mm, 1.92 mm, 2.1 mm, 2.28 mm, 2.4 mm, 2.52 mm, 2.7 mm, 2.88 mm, 3 mm, or other unlisted values. When H is 1 mm, H1 can be 2.5 mm, 2.6 mm, 2.8 mm, 3 mm, 3.2 mm, 3.5 mm, 3.8 mm, 4 mm, 4.2 mm, 4.5 mm, 4.8 mm, 5 mm, or other unlisted values.

[0097] In some embodiments, the depth of the recess 106 is H2, where H2 = eH, e is a fifth coefficient, and 1.5 ≤ e ≤ 3.5. Exemplarily, H2 can be 1.5H, 1.8H, 2H, 2.2H, 2.5H, 2.8H, 3H, 3.1H, 3.2H, 3.5H, or other unlisted values. When H is 0.4mm, H2 can be 0.6mm, 0.72mm, 0.8mm, 0.88mm, 1mm, 1.12mm, 1.2mm, 1.24mm, 1.28mm, 1.4mm, or other unlisted values. When H is 0.6mm, H2 can be 0.9mm, 1.08mm, 1.2mm, 1.32mm, 1.5mm, 1.68mm, 1.8mm, 1.86mm, 1.92mm, 2.1mm, or other unlisted values. When H is 1 mm, H2 can be 1.5 mm, 1.8 mm, 2 mm, 2.2 mm, 2.5 mm, 2.8 mm, 3 mm, 3.1 mm, 3.2 mm, 3.5 mm or other unlisted values.

[0098] Please see Figure 6 and Figure 7 The thickness of the area of ​​the first cover plate 102 without the explosion-proof notch 104 is H6, and the notch depth of the explosion-proof notch 104 is H32, where (H6-H32) = pH31, and p is the eleventh coefficient, 0.14≤p≤0.6. H6-H32 refers to the thickness of the first cover plate 102 at the explosion-proof notch 104. For ease of description, the thickness of the first cover plate 102 at the explosion-proof notch 104 is H60 (i.e., H60 = H6-H32), that is, H60 = pH32. It should be noted that when p is less than 0.14, the thickness of the first cover plate 102 at the explosion-proof notch 104 is small, and the structural strength of the first cover plate 102 at the explosion-proof notch 104 is weak. During normal battery use, the first cover plate 102 will break at the explosion-proof notch 104, affecting the normal use of the battery 1000. When p is greater than 0.6, the structural strength of the first 102 at the explosion-proof notch 104 is relatively weak, which will cause the welding plate 107 to disconnect from the first current collector 500 first, resulting in the battery 1000 breaking without being powered off, increasing the risk factor. For example, H60 can be 0.14H31, 0.15H31, 0.2H31, 0.22H31, 0.24H31, 0.29H31, 0.3H31, 0.35H31, 0.4H31, 0.42H31, 0.48H31, 0.5H31, 0.55H31, 0.6H31, or other unlisted values. When H31 is 0.5mm, H60 can be 0.07mm, 0.075mm, 0.1mm, 0.11mm, 0.12mm, 0.145mm, 0.15mm, 0.175mm, 0.2mm, 0.21mm, 0.24mm, 0.25mm, 0.275mm, 0.3mm, or other unlisted values. It should be noted that the depth of the explosion-proof notch 104 should not be too shallow; otherwise, when the internal air pressure of the battery 1000 increases, the explosion-proof notch 104 may fail to break, and the welding plate 107 will disconnect from the first current collector 500 first, leading to a battery explosion or even thermal runaway. The depth of the explosion-proof notch 104 should also not be too deep; otherwise, the first cover plate 102 may break during normal use.

[0099] In another embodiment, the thickness of the area of ​​the second cover plate portion 105 without the recessed portion 106 is H, the thickness of the area of ​​the first cover plate portion 102 without the explosion-proof notch 104 is H6, and the notch depth of the explosion-proof notch 104 is H32, (H6-H32)=qH, where q is the twelfth coefficient, 0.1≤q≤0.3. Here, H6-H32 refers to the thickness of the first cover plate portion 102 at the explosion-proof notch 104. For ease of description, the thickness of the first cover plate portion 102 at the explosion-proof notch 104 is H60 (i.e., H60=H6-H32). The thickness of the area of ​​the first cover plate portion 102 where the explosion-proof notch 104 is provided is the same as the thickness of the area of ​​the second cover plate portion 105 without the recessed portion 106, i.e., H6=H, thus H60=qH6. Specifically, when q is less than 0.1, the thickness of the first cover portion 102 at the explosion-proof notch 104 is small, and the structural strength of the first cover portion 102 at the explosion-proof notch 104 is weak. During normal battery use, the first cover portion 102 will break at the explosion-proof notch 104, affecting the normal use of the battery 1000. When q is greater than 0.3, the thickness of the first cover portion 102 at the explosion-proof notch 104 is large. When the gas pressure inside the battery 1000 reaches the second gas pressure, the first cover portion 102 cannot break at the explosion-proof notch 104, increasing the risk factor. For example, H60 can be 0.1H, 0.14H, 0.15H, 0.18H, 0.2H, 0.21H, 0.25H, 0.256H, 0.272H, 0.28H, 0.295H, 0.3H, or other unlisted values. Specifically, when H6 is 1 mm, H60 can be 0.1 mm, 0.14 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.21 mm, 0.25 mm, 0.256 mm, 0.272 mm, 0.28 mm, 0.295 mm, 0.3 mm, or other unlisted values.

[0100] It should be noted that, in the event of thermal runaway, the battery 1000 provided by this invention first disconnects the power and then depressurizes, thereby improving the safety performance of the battery 1000. Specifically, the cover plate body 101 has a normal state. In the normal state, the first cover plate portion 102 is also provided with a groove 108. The groove 108 has a bottom wall 109 and an inner side wall 110 connected to the bottom wall 109. An explosion-proof groove 104 is provided on the bottom wall 109. The groove 108 is located above the explosion-proof groove 104. When the internal air pressure of the battery 1000 increases, the air pressure acts on the cover plate assembly 100, pushing the cover plate assembly 100 to move away from the electrode assembly 300. Under the action of the first air pressure, the groove 108 is flattened (i.e., the inner side wall 110 of the groove 108 is flush with the upper end surface of the first cover plate portion 102, such as...). Figure 2 or Figure 3As shown in the figure, at this time, the first cover plate 102 has not yet broken, but the pole post assembly 400 is separated from the electrode assembly 300, thereby achieving power cut-off.

[0101] In some embodiments, please refer to Figure 6 and Figure 7 The thickness of the area of ​​the first cover plate portion 102 without the groove 108 is H3 (i.e., H3 = H6 = H), and the groove width of the groove 108 is H4, where H4 = kH3, k is the eighth coefficient, and 2 ≤ k ≤ 5. For example, H4 can be 2H3, 2.1H3, 2.4H3, 2.5H3, 2.8H3, 3H3, 3.5H3, 3.7H3, 3.8H3, 4.2H3, 4.5H3, 5H3, or other unlisted values. Specifically, when H3 is 1mm, H4 can be 2mm, 2.1mm, 2.4mm, 2.5mm, 2.8mm, 3mm, 3.5mm, 3.7mm, 3.8mm, 4.2mm, 4.5mm, 5mm, or other unlisted values.

[0102] In some embodiments, the depth of the groove 108 is H5, where H5 = mH3, and m is a ninth coefficient, 1 ≤ m ≤ 2. It should be noted that when m is less than 1, the groove 108 is too shallow. When the air pressure inside the battery 100 reaches the first air pressure, the explosion-proof notch 104 may break preferentially, causing the battery 1000 to fail to disconnect power normally. When m is greater than 2, the groove 108 is too deep. When the air pressure inside the battery 1000 reaches the first air pressure, the terminal assembly 400 and the electrode assembly 300 may not have broken, causing the battery 1000 to fail to disconnect power, increasing the risk. For example, H5 can be 1H3, 1.1H3, 1.18H3, 1.2H3, 1.22H3, 1.25H3, 1.3H3, 1.44H3, 1.5H3, 1.62H3, 1.72H3, 1.8H3, 1.85H3, 1.9H3, 1.92H3, 1.96H3, 2H3, or other unlisted values. Specifically, when H3 is 1mm, H5 can be 1mm, 1.1mm, 1.18mm, 1.2mm, 1.22mm, 1.25mm, 1.3mm, 1.44mm, 1.5mm, 1.62mm, 1.72mm, 1.8mm, 1.85mm, 1.9mm, 1.92mm, 1.96mm, 2mm, or other unlisted values.

[0103] In some embodiments, the thickness of the area of ​​the bottom wall 109 without the explosion-proof notch 104 is H6, where H6 = nH3, n is a coefficient, and 0.5 ≤ n ≤ 1. It should be noted that when n is less than 0.5, the thickness of the bottom wall 109 is small, the structural strength of the first cover portion 102 is weak, and the battery 1000 will break during normal use. When n is greater than 1, the thickness of the bottom wall 109 is large, the space occupied by the cover assembly 100 increases, and since the explosion-proof notch 104 is provided on the bottom wall 109, the force required for the explosion-proof notch 104 to break increases when the thickness of the bottom wall 109 increases, increasing the risk factor. Exemplarily, H6 can be 0.5H3, 0.52H3, 0.55H3, 0.6H3, 0.62H3, 0.7H3, 0.8H3, 0.9H3, 0.96H3, 1H3, or other unlisted values. Specifically, when H3 is 1 mm, H6 can be 0.5 mm, 0.52 mm, 0.55 mm, 0.6 mm, 0.62 mm, 0.7 mm, 0.8 mm, 0.9 mm, 0.96 mm, 1 mm, or other unlisted values.

[0104] To facilitate the disconnection of the terminal assembly 400 and the electrode assembly 300, the inner wall 110 is inclined relative to the bottom wall 109, with an angle α between them, where 55°≤α≤135°. Specifically, when α is less than 55°, the inner wall 110 surrounds the explosion-proof notch 104, providing some protection and preventing the notch 104 from breaking under the second atmospheric pressure. Simultaneously, the electrode assembly 300 and the terminal assembly 400 require greater force to disconnect, increasing the risk. When α is greater than 135°, the inner wall 110 and the bottom wall are nearly straight, increasing the distance between the terminal assembly 400 and the electrode assembly 300, thus increasing the overall space occupied by the battery 1000. In this embodiment, α can be 55°, 60°, 62°, 75°, 78°, 80°, 84°, 90°, 92°, 99°, 100°, 110°, 115°, 120°, 125°, 130°, 132°, 135° or other unlisted values.

[0105] It should be noted that the groove 108 protrudes into the inner cavity 201, and the cover plate body 101 also has an abnormal state. The first cover plate portion 102 of the cover plate body 101 in the abnormal state is flatter than the first cover plate portion 102 of the cover plate body 101 in the normal state.

[0106] Please see Figure 10In this embodiment, the terminal assembly 400 serves as one output terminal, and the cover plate body 101 serves as the other output terminal. The cover plate body 101 and the terminal assembly 400 are located on the same side. To prevent short circuits, the cover plate assembly 100 also includes an insulating member 113. The insulating member 113 is disposed between the terminal assembly 400 and the first connecting plate 111, serving as an insulator to prevent the terminal assembly 400 from contacting the cover plate body 101 and causing a short circuit. Furthermore, the first cover plate portion 102 includes a first connecting plate 111 and a second connecting plate 112 connected to the outer periphery of the first connecting plate 111. Explosion-proof grooves 104 are provided on the second connecting plate 112, and the insulating member 113 abuts against the second connecting plate 112. This arrangement allows the second connecting plate 112 to limit and fix the insulating member 113, preventing the insulating member 113 from slipping and causing a short circuit inside the battery 1000.

[0107] Furthermore, the insulating component 113 includes a first insulating portion 114 and a second insulating portion 115. The first connecting plate 111 is located between the first insulating portion 114 and the second insulating portion 115. The first insulating portion 114 and the second insulating portion 115 enclose the first connecting plate 111. The purpose of this arrangement is to enable the insulating component 113 to provide a certain degree of protection for the first connecting plate 111. When the internal air pressure of the battery 1000 increases, the first connecting plate 111 will not break first, so that the breakage location is at the explosion-proof notch 104 of the second connecting plate 112. The second insulating portion 115 is located on the side of the first connecting plate 111 near the inner cavity 201. The second connecting plate 112 is recessed towards the inner cavity 201, and the end of the second insulating portion 115 facing away from the terminal assembly 400 abuts against the side of the second connecting plate 112.

[0108] In some embodiments, explosion-proof grooves 104 are provided around the first hole 103, which allows the terminal assembly 400 and the electrode assembly 300 to be completely disconnected, so that the battery 1000 is in a power-off state, thereby reducing the probability of thermal runaway.

[0109] The present invention also proposes a battery pack, which includes a plurality of batteries 1000, each battery 1000 including a cover assembly 100. The specific structures of the batteries 1000 and the cover assembly 100 are as described in the above embodiments. Since this battery pack adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0110] Furthermore, the battery pack also includes a housing with a receiving cavity formed inside. Multiple batteries 1000 are spaced apart within the receiving cavity. The multiple batteries 1000 can be connected in parallel or in series, depending on the actual situation. It should be noted that by using the aforementioned batteries 1000, the battery pack described herein offers higher safety performance and more stable operation.

[0111] Furthermore, the present invention also proposes an electrical device comprising the aforementioned battery pack. The specific structure of the battery pack is described in the above embodiments. Since this electrical device employs all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here.

[0112] It is understood that the electrical equipment mentioned includes, but is not limited to, electric toys, power tools, electric vehicles, automobiles, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc. Automobiles can be gasoline-powered vehicles, natural gas-powered vehicles, and new energy vehicles.

[0113] The embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A cover assembly applied to a battery (1000), the battery (1000) comprising a battery casing (200) having an inner cavity (201), a terminal assembly (400), and an electrode assembly (300) mounted within the inner cavity (201), characterized in that, The cover assembly (100) includes a cover body (101) for connecting the battery housing (200) to seal the inner cavity (201), the cover body (101) comprising: The first cover plate (102) has a first hole (103) and an explosion-proof notch (104). The first hole (103) is for the electrode post assembly (400) to pass through and be electrically connected to the electrode assembly (300). The explosion-proof notch (104) is located outside the first hole (103). A second cover plate portion (105) is connected between the outer periphery of the first cover plate portion (102) and the battery casing (200), and the second cover plate portion (105) includes a reinforcing structure.

2. The cover plate assembly according to claim 1, characterized in that, The diameter of the circle containing the outer contour of the battery casing (200) projected along its axial direction is D1, the diameter of the circle containing the center line of the orthographic projection of the explosion-proof groove (104) on the horizontal plane is D2, and the diameter of the circle containing the center line of the orthographic projection of the reinforcing structure on the horizontal plane is D3, where D2 = aD1, D3 = bD1, a is a first coefficient, 0.4 ≤ a ≤ 0.75, and b is a second coefficient, 0.5 ≤ b ≤ 0.

8.

3. The cover plate assembly according to claim 2, characterized in that, The thickness of the cover plate body (101) is H, where D3-D2=2cH, c is the third coefficient, and c>3.

4. The cover plate assembly according to claim 1, characterized in that, The reinforcing structure includes a bending structure.

5. The cover plate assembly according to claim 4, characterized in that, The bending structure includes a recess (106) which is configured to be recessed into the inner cavity (201) from one side of the second cover plate portion (105).

6. The cover plate assembly according to claim 5, characterized in that, The electrode assembly (300) includes a first electrode (301) and a second electrode (302), wherein the first electrode (301) and the second electrode (302) have opposite polarities; The recess (106) is electrically connected to the first electrode (301), and the pole assembly (400) is electrically connected to the second electrode (302).

7. The cover plate assembly according to claim 6, characterized in that, The battery includes a first current collector (500); The recess (106) is provided with a welding plate (107), which is used to weld to the first current collector (500) to be electrically connected to the first electrode (301) through the first current collector (500). The thickness of the welding plate (107) is less than the thickness of the area of ​​the second cover plate (105) where the recess (106) is not provided.

8. The cover plate assembly according to claim 7, characterized in that, The thickness of the area of ​​the second cover plate (105) where the recess (106) is not provided is H, the thickness of the welding plate (107) is H31, and the thickness of the first collector (500) is H41, wherein H31 = fH, H41 = gH31, where f is the sixth coefficient, 0.5 ≤ f ≤ 0.7, and g is the seventh coefficient, 0.5 ≤ g ≤ 1.

2.

9. The cover plate assembly according to claim 6, characterized in that, The recess (106) is provided with a welding plate (107), which is used to electrically connect to the first electrode (301); The thickness of the welding plate (107) is less than the thickness of the area of ​​the second cover plate (105) where the recess (106) is not provided; The thickness of the welding plate (107) is H31, the thickness of the area of ​​the first cover plate (102) without the explosion-proof groove (104) is H6, and the groove depth of the explosion-proof groove is H32, where (H6-H32)=pH31, p is the eleventh coefficient, 0.14≤p≤0.

6.

10. The cover plate assembly according to claim 5, characterized in that, The thickness of the area of ​​the second cover plate (105) where the recess (106) is not provided is H, the thickness of the area of ​​the first cover plate (102) where the explosion-proof groove (104) is not provided is H6, the groove depth of the explosion-proof groove is H32, (H6-H32)=qH, q is the twelfth coefficient, 0.1≤q≤0.

3.

11. The cover plate assembly according to any one of claims 5-10, characterized in that, The thickness of the area of ​​the second cover plate portion (105) where the recessed portion (106) is not provided is H, the width of the recessed portion (106) is H1, and the depth of the recessed portion (106) is H2, wherein H1 = dH, H2 = eH, d is the fourth coefficient, 2.5 ≤ d ≤ 5, and e is the fifth coefficient, 1.5 ≤ e ≤ 3.

5.

12. The cover plate assembly according to any one of claims 1-10, characterized in that, The cover plate body (101) is in a normal state. In the normal state, the first cover plate part (102) is also provided with a groove (108). The groove (108) has a bottom wall (109) and an inner side wall (110) connected to the bottom wall (109). The explosion-proof groove (104) is provided on the bottom wall (109).

13. The cover plate assembly according to claim 12, characterized in that, The thickness of the area of ​​the first cover plate (102) without the groove (108) is H3, the groove width of the groove (108) is H4, the depth of the groove (108) is H5, and the thickness of the area of ​​the bottom wall (109) without the explosion-proof groove (104) is H6, where H4 = kH3, H5 = mH3, H6 = nH3, k is the eighth coefficient, 2 ≤ k ≤ 5, m is the ninth coefficient, 1 ≤ m ≤ 2, and n is the tenth coefficient, 0.5 ≤ n ≤ 1.

14. The cover plate assembly according to claim 12, characterized in that, The inner sidewall (110) is inclined relative to the bottom wall (109), and the included angle between the inner sidewall (110) and the bottom wall (109) is α, where 55°≤α≤135°.

15. The cover plate assembly according to claim 12, characterized in that, The groove (108) protrudes toward the inner cavity (201), and the cover plate body (101) also has an abnormal state, wherein the first cover plate portion (102) of the cover plate body (101) in the abnormal state is flatter than the first cover plate portion (102) of the cover plate body (101) in the normal state.

16. The cover plate assembly according to any one of claims 1-10, characterized in that, The first cover plate (102) includes a first connecting plate (111) and a second connecting plate (112) connected to the outer periphery of the first connecting plate (111), and the explosion-proof groove (104) is provided on the second connecting plate (112); The cover plate assembly (100) further includes an insulating member (113), which is disposed between the pole post assembly (400) and the first connecting plate (111) and abuts against the second connecting plate (112).

17. The cover plate assembly according to claim 16, characterized in that, The insulating component (113) includes a first insulating part (114) and a second insulating part (115), and the first connecting plate (111) is located between the first insulating part (114) and the second insulating part (115); The second insulating part (115) is located on the side of the first connecting plate (111) near the inner cavity (201), the second connecting plate (112) is recessed towards the inner cavity (201), and the end of the second insulating part (115) facing away from the pole assembly (400) abuts against the side of the second connecting plate (112).

18. The cover plate assembly according to any one of claims 1-10, characterized in that, The explosion-proof groove (104) is provided around the first hole (103).

19. A battery, characterized in that, include: The battery casing (200) has an inner cavity (201); An electrode assembly (300) is installed in the inner cavity (201); The electrode assembly (400) is electrically connected to the electrode assembly (300); and, The cover assembly (100) as claimed in any one of claims 1-18, the cover assembly (100) is connected to the battery housing (200) and seals the inner cavity (201).

20. The battery according to claim 19, characterized in that, When the air pressure in the inner cavity (201) is the first air pressure, the pole assembly (400) is disconnected from the electrode assembly (300); When the air pressure inside the inner cavity (201) is the second air pressure, the cover plate assembly (100) breaks at the explosion-proof notch (104); Wherein, the first air pressure is P1, the second air pressure is P2, 1.2Mpa≤P1≤1.8Mpa, P2>1.8Mpa.

21. A battery pack, characterized in that, Includes multiple batteries (1000) as described in claim 19 or 20.

Images