Explosion-proof structure, battery and battery pack

Abstract

The invention discloses an explosion-proof structure, a battery and a battery pack, the explosion-proof structure comprises a cover plate and an explosion-proof groove, the explosion-proof groove is arranged on the cover plate, the explosion-proof groove comprises a first sub-groove and a second sub-groove, the thickness of the cover plate at the position where the first sub-groove is located is H1, the thickness of the cover plate at the position where the second sub-groove is located is H2, H1 is smaller than H2, and under first pressure, the thickness of the first sub-groove is smaller than H2; under the first pressure, the cover plate at the first sub-tank is opened, under the second pressure, the cover plate at the second sub-tank is opened, the first pressure is P1, P1 is larger than 0.5 Mpa and smaller than 1.5 Mpa, the second pressure is P2, and P2 is larger than or equal to 1.5 Mpa and smaller than 2.5 Mpa. The explosion-proof structure solves the problems that when an existing explosion-proof structure is exploded, combustible gas, combustion-supporting gas and substances in the battery interact, the thermal runaway degree is increased, and battery explosion is caused, and has the advantages of being simple in structure and good in explosion-proof characteristic.

Description

[0001] This application claims the priority of the international application with the application number PCT / CN2023 / 143529, which was filed on December 29, 2023. The entire content of the above application is incorporated herein by reference. Technical Field

[0002] This application belongs to the technical field of batteries, and in particular, relates to an explosion-proof structure, a battery, and a battery pack. Background Art

[0003] During the use of power batteries, due to short circuits or other reasons, the internal pressure of the battery may increase and exceed the safety value, resulting in potential hazards such as explosions. To minimize such hazards, an explosion-proof diaphragm is generally provided on the battery cover plate. The explosion-proof diaphragm gradually deforms until it explodes and opens as the internal pressure increases.

[0004] During the thermal runaway process of the battery, when the battery temperature rises to a certain stage, the internal electrolyte will decompose into combustible gases such as methane. As the battery temperature continues to rise, the battery will also decompose into combustion-supporting gases such as oxygen. When the internal pressure of the battery further increases, the explosion-proof diaphragm bursts. At the moment when the explosion-proof valve bursts, the combustible gas, the combustion-supporting gas, and the battery internal substances interact with each other, exacerbating the degree of thermal runaway and easily causing the battery to explode. Summary of the Invention

[0005] Embodiments of this application provide an explosion-proof structure, a battery, and a battery pack to solve the problem that when the explosion-proof structure in the related art explodes and opens, the interaction between the combustible gas, the combustion-supporting gas, and the battery internal substances exacerbates the degree of thermal runaway and causes the battery to explode.

[0006] In a first aspect, embodiments of this application provide an explosion-proof structure applied to a battery, including:

[0007] A cover plate;

[0008] An explosion-proof groove provided on the cover plate. The explosion-proof groove includes a first sub-groove and a second sub-groove. The thickness of the cover plate at the position of the first sub-groove is H1, and the thickness of the cover plate at the position of the second sub-groove is H2, where H1 < H2. Among them, under a first pressure, the cover plate at the first sub-groove opens, and under a second pressure, the cover plate at the second sub-groove opens. The first pressure is P1, 0.5 Mpa < P1 < 1.5 Mpa, and the second pressure is P2, 1.5 Mpa ≤ P2 < 2.5 Mpa.

[0009] In a second aspect, embodiments of this application further provide a battery, which includes:

[0010] The explosion-proof structure as described above;

[0011] A wound core;

[0012] A housing, with the core wound installed inside the housing. One end of the housing is provided with an opening, and a cover plate is hermetically connected to the housing to block the opening.

[0013] In a third aspect, an embodiment of the present application further provides a battery pack, including the battery as described above.

[0014] The explosion-proof structure, cover plate assembly, and battery provided by the embodiments of the present application, by providing a first sub-groove and a second sub-groove on the cover plate, where the thickness of the cover plate at the position of the first sub-groove is less than the thickness of the cover plate at the position of the second sub-groove. When the internal pressure of the battery increases, the position of the first sub-groove on the cover plate opens first, and then the position of the second sub-groove on the cover plate opens, forming a secondary pressure relief of the battery. The first opening can discharge combustible gases, and the second opening can discharge combustion-supporting gases, thereby achieving the purpose of discharging combustible gases and combustion-supporting gases at different times. The design that the minimum value of the first pressure P1 is greater than 0.5 Mpa and the maximum value is less than 1.5 Mpa is reasonable, which can enable the combustible gases decomposed from the electrolyte to be discharged first, avoiding the situation of opening during normal battery operation. The minimum value of the second pressure P2 is 1.5 Mpa and the maximum value is less than 2.5 Mpa, avoiding the occurrence of battery explosion. It overcomes the problem that when the existing explosion-proof structure explodes and opens, due to the interaction of combustible gases, combustion-supporting gases, and the substances inside the battery, the degree of thermal runaway is aggravated, causing the battery to explode. It has the advantages of simple structure and good explosion-proof characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a top view of the first form of the explosion-proof structure provided by the embodiment of the present application.

[0016] Figure 2 It is a top view of the first form based on the first form of the explosion-proof structure provided by the embodiment of the present application.

[0017] Figure 3 It is a top view of the second form based on the first form of the explosion-proof structure provided by the embodiment of the present application.

[0018] Figure 4 It is Figure 3 the A-A cross-sectional view in

[0019] Figure 5 It is Figure 3 the partial enlarged view at B in

[0020] Figure 6 It is Figure 5 the C-C cross-sectional view in

[0021] Figure 7 It is Figure 6 the partial enlarged view at D in

[0022] Figure 8 is Figure 5 the E-E cross-sectional view in

[0023] Figure 9 the marked drawing of the explosion-proof structure provided by the embodiment of the present application.

[0024] Figure 10 the perspective view of the explosion-proof structure provided by the embodiment of the present application.

[0025] Figure 11 the top view of the third form based on the first form of the explosion-proof structure provided by the embodiment of the present application.

[0026] Figure 12 the top view of the fourth form based on the first form of the explosion-proof structure provided by the embodiment of the present application.

[0027] Figure 13 the top view of the fifth form based on the first form of the explosion-proof structure provided by the embodiment of the present application.

[0028] Figure 14 the top view of the second form of the explosion-proof structure provided by the embodiment of the present application.

[0029] Figure 15 is Figure 14 the I-I cross-sectional view of

[0030] Figure 16 is Figure 14 the partial enlarged view at F in

[0031] Figure 17 is Figure 15 the partial enlarged view at G in

[0032] Figure 18 the top view of the explosion-proof groove provided on the second sub-part in the embodiment of the present application.

[0033] Figure 19 is Figure 18 the K-K cross-sectional view in

[0034] Figure 20 the marked drawing of the first sub-groove of the explosion-proof structure provided by the embodiment of the present application.

[0035] Figure 21 the top view of the fourth form of the explosion-proof structure provided by the embodiment of the present application.

[0036] Figure 22 is Figure 21 the L-L cross-sectional view in

[0037] Figure 23 is Figure 21 the marked drawing of

[0038] Figure 24 This is a perspective view of the battery provided by the embodiment of the present application.

[0039] Figure 25 It is Figure 24 the top view of

[0040] Figure 26 It is Figure 25 the sectional view taken along line G-G in

[0041] Figure 27 It is Figure 26 the partial enlarged view at position H in

[0042] Figure 28 It is Figure 26 the partial enlarged view at position M in

[0043] Figure 29 This is a partial perspective view of the battery pack provided by the embodiment of the present application.

[0044] Figure 30 It is Figure 29 the side view of

[0045] Figure 31 It is Figure 30 the sectional view taken along line H-H in

[0046] Explanation of reference numerals:

[0047] 100, battery; 110, cover plate; 111, first side; 1111, first section; 1112, second section; 1113, first end; 1114, second end; 1115, third end; 1116, fourth end; 1117, third section; 112, second side; 1121, fifth end; 1122, sixth end; 113, first sub-part; 114, second sub-part; 1141, sunken platform; 1142, convex platform; 115, third sub-part; 116, fourth sub-part; 120, explosion-proof groove; 121, first sub-groove; 1211, first groove wall; 1212, second groove wall; 122, second sub-groove; 130, mounting seat; 131, mounting groove; 132, baffle; 133, first sub-plate; 134, second sub-plate; 140, winding core; 150, housing; 151, opening; 152, positive terminal; 153, flange; 154, pressing plate; 155, seal; 160, first current collector plate; 170, second current collector plate; 180, insulating part. Detailed implementation manners

[0048] The embodiment of the present application provides an explosion-proof structure, a battery and a battery pack to solve the problem that when the explosion-proof structure in the related art explodes, the interaction of combustible gas, combustion-supporting gas and the substances in the battery intensifies the degree of thermal runaway and causes the battery to explode. The following will be described with reference to the drawings.

[0049] See Figure 1 , Figure 2 , Figure 3 , Figure 14 , Figure 18 and Figure 21 As shown, an explosion-proof structure provided by an embodiment of the present application is applied to a battery. The battery can be a cylindrical battery. The explosion-proof structure includes a cover plate 110 and an explosion-proof groove 120. The cover plate 110 has a disc-shaped structure. The material of the cover plate 110 can be steel, such as materials like SPCC material, stainless steel materials SUS410, SUS306, SUS316, SUS430, SUS444, etc. When using SPCC material, nickel can be plated on both surfaces of the cover plate 110, and the thickness of the plating layer is 0.3 μm to 8 μm. The plating layer thickness on both sides of the cover plate 110 can be the same or different. An explosion-proof groove 120 is integrally provided on the cover plate 110. The explosion-proof groove 120 includes a first sub-groove 121 and a second sub-groove 122. The thickness of the cover plate 110 at the position where the first sub-groove 121 is located is H1, and the thickness of the cover plate at the position where the second sub-groove 122 is located is H2, and H1 < H2. Among them, under the first pressure, the cover plate 110 at the first sub-groove 121 opens, and under the second pressure, the cover plate 110 at the second sub-groove 122 opens. The first pressure is P1, 0.5 Mpa < P1 < 1.5 Mpa, and the second pressure is P2, 1.5 Mpa ≤ P2 < 2.5 Mpa. Among them, both the first pressure and the second pressure refer to the pressure inside the battery.

[0050] Under normal operating conditions of the battery, the internal pressure of the battery will reach 0.5 Mpa. Generally, during a period of time before the battery touches thermal runaway, the internal pressure increases with the increase of temperature and the decomposition of the electrolyte. In order to let the combustible gas decomposed from the electrolyte be discharged first and not cause the opening under normal battery operation, the first pressure P1 is set between (0.5 Mpa, 1.5 Mpa), such as P1 is set to 0.6 Mpa, 0.7 Mpa, 0.8 Mpa, 0.9 Mpa, 1.0 Mpa, 1.1 Mpa, 1.2 Mpa, 1.3 Mpa, 1.4 Mpa or other unlisted values. At the end stage of battery thermal runaway, when the internal pressure of the battery rises to a certain extent, the explosion-proof valve needs to open and release the combustion substances inside the battery to avoid the occurrence of battery explosion. The second pressure P2 is set between [1.5 Mpa, 2.5 Mpa), such as P2 is set to 1.6 Mpa, 1.7 Mpa, 1.8 Mpa, 1.9 Mpa, 2.0 Mpa, 2.1 Mpa, 2.2 Mpa, 2.3 Mpa, 2.4 Mpa or other unlisted values.

[0051] Since the thickness of the cover plate 110 at the position of the first sub-groove 121 is less than the thickness of the cover plate 110 at the position of the second sub-groove 122, as the air pressure inside the battery increases, the position of the first sub-groove 121 on the cover plate 110 is opened first, and then the position of the second sub-groove 122 on the cover plate 110 is opened. The cover plate 110 at the first sub-groove 121 is opened under the first pressure, and the first sub-groove 121 is opened to discharge combustible substances. The cover plate 110 at the second sub-groove 122 is opened under the second pressure, and the second sub-groove 122 is opened to discharge combustion-supporting substances. The first pressure is less than the second pressure, and the first pressure and the second pressure are set reasonably. Under the condition of ensuring the normal operation of the battery, secondary pressure relief of the battery is realized. The first opening can discharge combustible gas, and the second opening can discharge combustion-supporting gas, so as to achieve the purpose of discharging combustible gas and combustion-supporting gas at different times, and overcome the problem that when the explosion-proof structure in the related technology explodes and opens, due to the interaction of combustible gas, combustion-supporting gas and the substances inside the battery, the degree of thermal runaway is aggravated, resulting in battery explosion.

[0052] The above explosion-proof structure has various forms, which will be described in detail below with reference to the drawings.

[0053] Form 1: Refer to Figure 1 As shown, the cover plate 110 includes a first side surface 111 and a second side surface 112 arranged oppositely. The first sub-groove 121 and the second sub-groove 122 are both arranged on the first side surface 111. Arranging the first sub-groove 121 and the second sub-groove 122 on the first side surface 111 of the cover plate 110 is convenient for the processing of the first sub-groove 121 and the second sub-groove 122. The first sub-groove 121 and the second sub-groove 122 are communicated, and the first sub-groove 121 and the second sub-groove 122 form a closed ring on one side surface of the cover plate 110. The projections of the first sub-groove 121 and the second sub-groove 122 on one side surface of the cover plate 110 form a closed ring. While ensuring the pressure relief area, after the cover plate 110 at the position of the first sub-groove 121 is opened, the cover plate 110 at the position of the second sub-groove 122 is broken through from the connection part of the first sub-groove 121 and the second sub-groove 122, which is beneficial to the opening of the cover plate 110 at the position of the second sub-groove 122, ensuring that the explosion-proof structure can be opened smoothly, and a part of the cover plate 110 inside the first sub-groove 121 and the second sub-groove 122 is completely separated from a part of the cover plate 110 outside the first sub-groove 121 and the second sub-groove 122, realizing the complete opening of the explosion-proof structure and ensuring the explosion-proof effect.

[0054] Form 2: Refer to Figure 14 and Figure 16As shown, along the radial direction of the cover plate 110, the second sub-groove 122 is annular, and the first sub-groove 121 is arranged at an interval from the second sub-groove 122. Among them, the first sub-groove 121 includes a first section 1111 and a second section 1112. The first section 1111 has a first end 1113 and a second end 1114, and the second section 1112 has a third end 1115 and a fourth end 1116. The distance between the first end 1113 and the third end 1115 is greater than the distance between the second end 1114 and the fourth end 1116. Among them, the first sub-groove 121 is closer to the center of the cover plate 110 than the second sub-groove 122. When the second sub-groove 122 is opened under the second pressure P2, the cover plate 110 inside the second sub-groove 122 is completely separated from the cover plate 110 outside the second sub-groove 122, and the opening for secondary pressure relief is large enough to ensure the pressure relief effect and avoid the occurrence of battery explosion.

[0055] Form three: Refer to Figure 21 As shown, the second sub-groove 122 is arc-shaped. The second sub-groove 122 includes a fifth end 1121 and a sixth end 1122. The first sub-groove 121 is located between the fifth end 1121 and the sixth end 1122. The first sub-groove 121 includes a first section 1111 and a second section 1112. The first section 1111 has a first end 1113 and a second end 1114, and the second section 1112 has a third end 1115 and a fourth end 1116. The distance between the first end 1113 and the third end 1115 is greater than the distance between the second end 1114 and the fourth end 1116.

[0056] Form four, on the basis of form three, refer to Figure 21 As shown, the first sub-groove 121 is communicated with the second sub-groove 122. The first end 1113 is connected to the fifth end 1121, and the third end 1115 is connected to the sixth end 1122. The first sub-groove 121 and the second sub-groove 122 are communicated to form a closed shape. When the first sub-groove 121 is opened under the first pressure, the second sub-groove 122 is opened from the first end 1113 and the third end 1115 of the first sub-groove 121 under the second pressure, which is beneficial to the opening of the second sub-groove 122, and the closed shape formed by the first sub-groove 121 and the second sub-groove 122 is relatively large. Under the second pressure, the cover plate 110 inside the first sub-groove 121 and the second sub-groove 122 is completely separated from the cover plate 110 outside, and the pressure relief port is large enough to ensure the pressure relief effect and prevent battery blockage.

[0057] In some embodiments, the first section 1111 and the second section 1112 of the first sub-groove 121 are line segments, and a certain angle is formed between the first section 1111 and the second section 1112. When the first sub-groove 121 is opened, it is first opened from the connection end of the first section 1111 and the second section 1112, and extends along the directions of the first section 1111 and the second section 1112 to realize the complete opening of the first sub-groove 121.

[0058] In some embodiments, refer toFigure 16 As shown, the first section 1111 and the second section 1112 of the first sub-slot 121 are both arcs, which can increase the length of the first sub-slot 121 as much as possible, increase the size of the pressure relief port when the first sub-slot 121 is opened, and ensure the effect of one-time pressure relief.

[0059] In some embodiments, referring to Figure 16 As shown, the first sub-slot 121 further includes a third section 1117, and the third section 1117 is arranged between the second end 1114 and the fourth end 1116. The third section 1117 is smoothly connected to the first section 1111 and the second section 1112 to ensure that the first sub-slot 121 can be opened smoothly.

[0060] In some embodiments, referring to Figure 16 As shown, the first section 1111, the second section 1112 and the third section 1117 are all arcs, and the bending directions of the first section 1111 and the second section 1112 are different from the bending direction of the third section 1117. To achieve a smooth transition connection between the first section 1111 and the second section 1112, and increase the one-time pressure relief port as much as possible to ensure the smooth opening of the one-time pressure relief.

[0061] In some embodiments, referring to Figure 20 As shown, an included angle β is formed between the chord corresponding to the arc of the first section 1111 and the chord corresponding to the arc of the second section 1112, where 30° ≤ β ≤ 150°. Such as β takes values of 30°, 40°, 50°, 60°, 70°, 80°, 90°, 100°, 110°, 120°, 130°, 140°, 150° or other unlisted values. The chord corresponding to the arc of the first section 1111 refers to the straight line where the chord of the inner arc of the first section 1111 is located, and the chord corresponding to the arc of the second section 1112 refers to the straight line where the chord of the inner arc of the second section 1112 is located. The angle between the first section 1111 and the second section 1112 is reasonable. Within the span range, the larger the included angle β, the longer the length of the first sub-slot 121 corresponding to it, and the earlier the cover plate 110 at the first sub-slot 121 is opened. The included angle β can be set as needed.

[0062] In some embodiments, referring to Figure 20As shown, the arc length of the first section 1111 is L1, the arc length of the second section 1112 is L2, and the arc length of the third section 1117 is L3, 4mm≤L1=L2≤8mm, 1mm≤L3≤3mm. The first section 1111 and the second section 1112 are symmetrically arranged, 1mm≤L3≤3mm, wherein the value of L3 can be 1mm, 2mm, 3mm or other unspecified values, 4mm≤L1=L2≤8mm, and the values ​​of L1 and L2 can be 4mm, 5mm, 6mm, 7mm, 8mm or other unspecified values. The arc lengths of the first section 1111, the second section 1112 and the third section 1117 are reasonably arranged. When pressure is released, the arc lengths break through the third section 1117 and extend to both sides. The first section 1111 and the second section 1112 are symmetrically arranged, so that the forces on both sides are the same, the opening speed is the same, and the reliability of one-time pressure release is ensured.

[0063] In some embodiments, see Figure 16 As shown, the second end 1114 is closer to the center of the cover plate 110 than the first end 1113, and the fourth end 1116 is closer to the center of the cover plate 110 than the third end 1115. As a variation, the first end 1113 is closer to the center of the cover plate 110 than the second end 1114, and the third end 1115 is closer to the center of the cover plate 110 than the fourth end 1116. The protruding direction of the first sub-groove 121 can be reasonably arranged according to the actual size of the cover plate 110.

[0064] In some embodiments, the cross-sectional shape of the explosion-proof groove 120 along the thickness direction of the cover plate 110 is V-shaped, trapezoidal, semicircular, "U"-shaped or parabolic. The cross-sectional shape of the first sub-groove 121 can be the same as the cross-sectional shape of the second sub-groove 122, and the cross-sectional shape of the explosion-proof groove 120 can be reasonably set according to the processing technology.

[0065] In some embodiments, see Figure 1 , Figure 2 , Figure 3 , Figure 9 , Figure 18 and Figure 23 As shown, along the top view of the cover plate 110, the outer diameter of the ring where the second sub-groove 122 is located is E1, 24mm≤E1≤40mm, such as, 30mm≤E1≤35mm. Among them, the value of E1 can be 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm, 40mm or other unspecified values. The position of the second sub-groove 122 on the cover plate 110 is reasonably set to form a sufficiently large pressure relief area to ensure the pressure relief effect.

[0066] In some embodiments, seeFigure 6 , Figure 7 and Figure 17 As shown, the thickness of the cover plate 110 at the first sub-groove 121 is H1, and the thickness of the cover plate 110 at the second sub-groove 122 is H2, wherein 20μm≤H1≤115μm, 25μm≤H2≤135μm. For example, 45μm≤H1≤55μm, 80μm≤H2≤100μm. The value of H1 can be 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 115μm or other unspecified values. The value of H2 can be 25μm, 35μm, 45μm, 55μm, 65μm, 75μm, 85μm, 95μm, 105μm, 115μm, 125μm, 135μm or other unlisted values.

[0067] It can be understood that the thicker the cover plate 110 at the location of the explosion-proof groove 120, the greater the pressure required to open the explosion-proof groove 120. The thickness of the cover plate 110 at the location of the explosion-proof groove 120 is positively correlated with the pressure required to open the explosion-proof groove 120. If the thickness of the cover plate 110 at the location of the explosion-proof groove 120 is thin, the explosion-proof groove 120 may be opened within the normal working range of the battery, affecting the performance of the battery. If the thickness of the cover plate 110 at the location of the explosion-proof groove 120 is thick, the pressure required to open the explosion-proof groove 120 is large, and the battery is prone to explosion. In the embodiment of the present application, the thickness range of the cover plate 110 where the explosion-proof groove 120 is located is reasonably designed, while meeting the normal working of the battery, achieving secondary pressure relief, and preventing the battery from exploding.

[0068] In some embodiments, 5 μm ≤ H2-H1 ≤ 20 μm. The value of H2-H1 can be 5 μm, 10 μm, 15 μm, 20 μm or other unspecified values. The difference between H2 and H1 is set within a reasonable range to ensure the reliability of the primary pressure relief and the secondary pressure relief.

[0069] In some embodiments, see Figure 7 , Figure 8 and Figure 17 As shown, the thickness of the area outside the explosion-proof groove 120 on the cover plate 110 is C, 0.4mm≤C≤1.0mm. Among them, the value of C can be 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm or other unspecified values. The thickness of the cover plate 110 is reasonably set, and the first sub-groove 121 and the second sub-groove 122 can be processed while ensuring the strength of the cover plate 110 to achieve secondary pressure relief.

[0070] In some embodiments, based on Form 1, seeFigure 3 As shown, the arc length of the first sub-groove 121 is less than that of the second sub-groove 122. Here, the arc length of the first sub-groove 121 refers to the length of the arc where the outer edge of the explosion-proof groove 120 is located at the position of the first sub-groove 121, and the arc length of the second sub-groove 122 refers to the length of the arc where the outer edge of the explosion-proof groove 120 is located at the position of the second sub-groove 122.

[0071] In some embodiments, on the basis of Form 1, refer to Figure 3 As shown, the ratio of the arc length of the first sub-groove 121 to that of the second sub-groove 122 is G. Here, wherein, the value of G can be or other unlisted values. Reasonably arrange the arc lengths of the first sub-groove 121 and the second sub-groove 122, and reasonably arrange the opening sizes of the primary pressure relief and the secondary pressure relief to ensure the explosion-proof effect.

[0072] In some embodiments, refer to Figure 8 and Figure 17 As shown, the width of the notch of the explosion-proof groove 120 is a, and 0.6mm ≤ a ≤ 1.5mm. Here, the value of a can be 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm or other unlisted values. Reasonably set the width of the notch of the explosion-proof groove 120 to avoid that the width of the notch of the explosion-proof groove 120 is too small and not conducive to processing and opening, and also avoid that the width of the notch of the explosion-proof groove 120 is too large, increasing the area of the explosion-proof groove 120 too much and affecting the structural strength of the cover plate 110.

[0073] In some embodiments, refer to Figure 1 and Figure 14 As shown, in the structures of Form 2 and Form 4, the outer diameter of the ring where the second sub-groove 122 is located is E1, and 24mm ≤ E1 ≤ 40mm, such as, 30mm ≤ E1 ≤ 35mm. Here, the value of E1 can be 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm, 40mm or other unlisted values. Reasonably set the position of the explosion-proof groove 120 on the cover plate 110 to form a sufficiently large pressure relief area and ensure the pressure relief effect.

[0074] In some embodiments, refer to Figure 11 and Figure 13As shown, on the basis of Form 1, the explosion-proof groove 120 includes a plurality of first sub-grooves 121 and a plurality of second sub-grooves 122. The first sub-grooves 121 and the second sub-grooves 122 are arranged alternately. The plurality of first sub-grooves 121 and the plurality of second sub-grooves 122 are located on the same circle. The projections of the plurality of first sub-grooves 121 and the plurality of second sub-grooves 122 on one side of the cover plate 110 enclose a closed ring.

[0075] It can be understood that in order to achieve secondary pressure relief, at the first pressure, the cover plate 110 at all the positions of the first sub-grooves 121 is opened. At the second pressure, the cover plate 110 at all the positions of the second sub-grooves 122 is opened. The first pressure is less than the second pressure. By providing a plurality of first sub-grooves 121 and a plurality of second sub-grooves 122 on the cover plate 110, it is beneficial for the cover plate 110 at the position where the explosion-proof groove 120 is located to be fully opened, ensuring the pressure relief area and guaranteeing the pressure relief effect.

[0076] In some embodiments, referring to Figure 2 and Figure 18 As shown, the cover plate 110 includes a first sub-part 113 and a second sub-part 114. The first sub-part 113 and the second sub-part 114 are adjacent. The first sub-part 113 is close to the edge of the cover plate 110. At least part of the surface of the second sub-part 114 facing the core 140 is higher than the surface of the first sub-part 113 facing the core 140. At least part of the surface of the second sub-part 114 away from the core 140 is higher than the surface of the first sub-part 113 away from the core 140. The explosion-proof groove 120 is arranged on the second sub-part 114.

[0077] It can be understood that the cover plate 110 is designed into a concave-convex structure. When the cover plate 110 is deformed, it is in a hemispherical or hat shape, increasing the space between the cover plate 110 and the end of the core 140, preventing the air pressure inside the battery from increasing sharply and causing the battery to explode.

[0078] On the basis of the above embodiments, referring to Figure 2 and Figure 18 As shown, the cover plate 110 includes a third sub-part 115. Along the radial direction of the cover plate 110, the first sub-part 113, the second sub-part 114 and the third sub-part 115 are concentrically arranged in sequence. The first sub-part 113 and the second sub-part 114 are annular, and the third sub-part 115 is circular. The first sub-part 113 is close to the edge of the cover plate 110. From the direction of the second side 112 pointing to the first side 111, at least part of the surface of the second sub-part 114 facing the core 140 is higher than the surface of the first sub-part 113 facing the core 140. At least part of the surface of the second sub-part 114 away from the core 140 is higher than the surface of the first sub-part 113 away from the core 140. The explosion-proof groove 120 is arranged on the second sub-part 114. The first sub-groove 121 and the second sub-groove 122 are concentric with the second sub-part 114.

[0079] It can be understood that when the air pressure inside the battery increases, the cover plate 110 bulges and deforms in the direction of the first side 111. By designing the heights of the second sub - part 114 and the third sub - part 115 to be higher than that of the first sub - part 113, the cover plate 110 becomes hemispherical or hat - shaped after deformation, increasing the space between the cover plate 110 and the end of the winding core 140, preventing the air pressure inside the battery from increasing sharply and causing the battery to explode.

[0080] In some embodiments, referring to Figure 2 and Figure 18 As shown, the cover plate 110 further includes a fourth sub - part 116. The fourth sub - part 116 is annular and is located between the second sub - part 114 and the third sub - part 115. The fourth sub - part 116 connects the second sub - part 114 and the third sub - part 115.

[0081] It can be understood that by arranging the explosion - proof groove 120 on the second sub - part 114, during the deformation process of the cover plate 110, the deformation forces of the first sub - part 113 and the fourth sub - part 116 act on the explosion - proof groove 120, which is beneficial to the smooth opening of the explosion - proof groove 120 and the reliability of the explosion - proof structure.

[0082] In other embodiments, it is also designed that the height of the third sub - part 115 on the first side 111 is higher than that of the second sub - part 114, the height of part of the second sub - part 114 is higher than that of the first sub - part 113, and the first sub - part 113 is higher than the fourth sub - part 116; on the second side 112, the fourth sub - part 116 is lower than the first sub - part 113, the first sub - part 113 is lower than at least part of the second sub - part 114, and the second sub - part 114 is lower than the third sub - part 115.

[0083] It can be understood that when the cover plate 110 is installed on the battery for use, the fourth sub - part 116 of the cover plate 110 is connected to the electrode of the battery, and the cover plate 110 is charged. For the battery, the electric potential between the cover plate 110 and the battery housing 150 is the same, there is no potential difference, reducing the risk of the cover plate 110 being corroded and improving the reliability of the battery pack.

[0084] In some embodiments, referring to Figure 8 and Figure 19 As shown, the distance between the first side 111 of the second sub - part 114 and the first side 111 of the first sub - part 113 is B, and 0.8C ≤ B ≤ 1.5C, where C is the thickness of the area outside the explosion - proof groove 120 on the cover plate 110. For example, B can take values such as 0.8C, 0.9C, 1.0C, 1.1C, 1.2C, 1.3C, 1.4C, 1.5C or other unlisted values.

[0085] In some embodiments, referring to Figure 9, in the structure of Form 1, the outer diameter of the ring where the second sub-slot 122 is located is E1, the inner diameter of the second sub-portion 114 is E2, the outer diameter of the second sub-portion 114 is E3, and the diameter of the cover plate 110 is E4, where 42 mm ≤ E4 ≤ 46 mm. For example, E4 can take values such as 42 mm, 43 mm, 44 mm, 45 mm, 46 mm or other unlisted values; 0.75E4 ≤ E3 ≤ 0.96E4, 0.4E4 ≤ E2 ≤ 0.72E4 and 3C ≤ E3 - E2 ≤ 27.8C; E2 + C < E1 < E3 - C, where C is the thickness of the area on the cover plate 110 outside the explosion-proof groove 120.

[0086] It can be understood that in the embodiments of the present application, the size of the diameter E4 of the cover plate 110 is related to the corresponding battery product specifications, the sizes of E2 and E3 are related to E4, the size of E1 is related to E2 and E3, and the structural dimensions of the cover plate 110 are reasonably designed. By reasonably setting the structures and parameters of the first sub-portion 113, the second sub-portion 114, the third sub-portion 115, and the fourth sub-portion 116, while ensuring the strength of the cover plate 110 and the space size after the deformation of the cover plate 110, the primary pressure relief and secondary pressure relief of the cover plate 110 are realized, which is convenient for the processing of the explosion-proof groove 120.

[0087] In some embodiments, as shown in Figure 3 , Figure 5 , Figure 10 , Figure 21 and Figure 22 , the second sub-portion 114 includes a connected counterbore 1141 and a boss 1142. The surface of the boss 1142 facing the core 140 is higher than the surface of the counterbore 1141 facing the core 140 and the surface of the first sub-portion 113 facing the core 140. The surface of the boss 1142 facing away from the core 140 is higher than the surface of the counterbore 1141 facing away from the core 140 and the surface of the first sub-portion 113 facing away from the core 140. The first sub-slot 121 is at least partially disposed on the counterbore 1141, and the second sub-slot 122 is at least partially located on the boss 1142. In the direction from the second side 112 to the first side 111, the counterbore 1141 and the first sub-portion 113 are at the same height, that is, the first side 111 of the counterbore 1141 and the first side 111 of the first sub-portion 113 are in the same horizontal plane, the second side 112 of the counterbore 1141 and the second side 112 of the first sub-portion 113 are in the same horizontal plane. The boss 1142 is disposed higher than the counterbore 1141. The first side 111 of the boss 1142 is higher than the first side 111 of the counterbore 1141, and the second side 112 of the boss 1142 is higher than the second side of the counterbore 1141. The first sub-slot 121 is at least partially disposed on the counterbore 1141, and the second sub-slot 122 is at least partially disposed on the boss 1142.

[0088] It can be understood that by forming a sunk platform 1141 and a boss 1142 on the second sub - part 114, the first sub - groove 121 is at least partially disposed on the sunk platform 1141, and the second sub - groove 122 is disposed on the boss 1142. When the air pressure inside the battery increases and the cover plate 110 deforms, the first sub - groove 121 at the position of the sunk platform 1141 is subjected to the acting force of the deformation of the cover plate 110, thereby realizing the directional opening at the position of the first sub - groove 121 and ensuring the orderly progress of secondary pressure relief. Among them, the directional opening at the position of the first sub - groove 121 includes the following two situations: under the first pressure, the first sub - groove 121 is instantaneously and completely opened; or, the first sub - groove 121 has an opening point, and the first sub - groove 121 starts to open from the opening point until it is completely opened. Refer to Figure 3 As shown, the opening point is the junction of the boss 1142 and the sunk platform 1141 on the first sub - groove 121, or can be any position on the first sub - groove 121 within the area of the sunk platform 1141. Refer to Figure 18 and Figure 21 As shown, the opening point is the junction of the boss 1142 and the sunk platform 1141 on the first sub - groove 121, or the opening point is any position on the third section 1117 of the first sub - groove 121, or the opening point is any position on the first section 1111 and the second section 1112 of the first sub - groove 121 within the area of the sunk platform 1141.

[0089] On the basis of the above - mentioned embodiment, the surface of the third sub - part 115 facing the winding core 140 is not lower than the surface of the boss 1142 facing the winding core 140, and the surface of the third sub - part 115 away from the winding core 140 is not lower than the surface of the boss 1142 away from the winding core 140. The space after the deformation of the cover plate 110 can be increased as much as possible.

[0090] On the basis of the above - mentioned embodiment, the surface of the first sub - part 113 facing the winding core 140 is higher than the surface of the fourth sub - part 116 facing the winding core 140, and the fourth sub - part 116 is used to connect with the electrode of the battery. When the cover plate 110 is installed on the battery for use, the fourth sub - part 116 of the cover plate 110 is connected with the electrode of the battery, and the cover plate 110 is charged. For the battery, the electric potential between the cover plate 110 and the battery housing 150 is the same, there is no potential difference, reducing the risk of corrosion of the cover plate 110 and improving the reliability of the battery pack. In addition, the surface of the first sub - part 113 away from the winding core 140 is higher than the surface of the fourth sub - part 116 away from the winding core 140.

[0091] On the basis of the above - mentioned embodiment, the surface of the first sub - part 113 facing the winding core 140, the surface of the fourth sub - part 116 facing the winding core 140, and the surface of the sunk platform 1141 facing the winding core 140 are at the same height. In addition, the surface of the first sub - part 113 away from the winding core 140, the surface of the fourth sub - part 116 away from the winding core 140, and the surface of the sunk platform 1141 facing the winding core 140 are at the same height, which is convenient for the processing and forming of the cover plate 110.

[0092] In some embodiments, referring to Figure 4 and Figure 22 as shown, the depth of the counterbore 1141 is A, where 0.8C ≤ A ≤ 1.5C. Here, C is the thickness of the area on the cover plate 110 outside the explosion-proof groove 120. For example, 1C ≤ A ≤ 1.3C, and A can be 0.8C, 0.9C, 1.0C, 1.1C, 1.2C, 1.3C, 1.4C, 1.5C or other unlisted values. The depth of the counterbore 1141 refers to the vertical distance between the first side 111 of the boss 1142 and the first side 111 of the counterbore 1141.

[0093] In some embodiments, referring to Figure 9 and Figure 23 as shown, the width of the top of the counterbore 1141 is D1, and the width of the bottom of the counterbore 1141 is D2, where

[0094] 4mm ≤ D1 ≤ 12mm;

[0095] D2 = D1 - 2C * tan(α - 90°), and D2 > 2mm;

[0096] α is the angle formed between the bottom and the side of the counterbore 1141, and 100° ≤ α ≤ 170°;

[0097] C is the thickness of the area on the cover plate 110 outside the explosion-proof groove 120.

[0098] Here, D1 can take values of 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm or other unlisted values, and α can take values of 100°, 110°, 120°, 130°, 140°, 150°, 160°, 170° or other unlisted values. Reasonably setting the dimensions of the counterbore 1141 ensures the effect of the directional opening of the explosion-proof structure.

[0099] In some embodiments, referring to Figure 12 as shown, the cover plate 110 includes a first side 111 and a second side 112 arranged opposite to each other. The first sub-groove 121 and the second sub-groove 122 are both arranged on the second side 112, and the first sub-groove 121 communicates with the second sub-groove 122.

[0100] It can be understood that setting the explosion-proof groove 120 on the side of the cover plate 110 close to the core is beneficial to the explosion of the explosion-proof groove 120 and ensures the explosion-proof effect.

[0101] In some embodiments, the cover plate 110 includes a first side 111 and a second side 112 arranged opposite to each other. The first sub-groove 121 is arranged on the first side 111, and the second sub-groove 122 is arranged on the second side 112.

[0102] As a variant, the cover plate 110 includes a first side surface 111 and a second side surface 112 which are oppositely arranged. The second sub-groove 122 is arranged on the first side surface 111, and the first sub-groove 121 is arranged on the second side surface 112.

[0103] It can be understood that the first sub-groove 121 and the second sub-groove 122 can be arranged on both sides of the cover plate 110 in different planes, which is convenient for processing.

[0104] In some embodiments, on the basis of Form 1 and Form 2, the thickness H2 of the cover plate 110 at the second sub-groove 122 is calculated according to the following formula (1):

[0105]

[0106] Wherein, Q is the tensile strength of the material for preparing the cover plate 110;

[0107] E1 is the outer diameter of the ring where the second sub-groove 122 is located;

[0108] P2 is the opening pressure of the cover plate 110 at the second sub-groove 122.

[0109] In some embodiments, on the basis of Form 1, the thickness H1 of the cover plate 110 at the first sub-groove 121 is calculated according to the following formula (2):

[0110]

[0111] Wherein, Q is the tensile strength of the material for preparing the cover plate 110;

[0112] E1 is the outer diameter of the ring where the second sub-groove 122 is located, and the outer diameters of the first sub-groove 121 and the second sub-groove 122 are the same;

[0113] P1 is the opening pressure of the cover plate 110 at the first sub-groove 121.

[0114] The thickness H1 of the cover plate 110 at the first sub-groove 121 and the thickness H2 of the cover plate 110 at the second sub-groove 122 are calculated by using the above formula (1) and formula (2). The first sub-groove 121 and the second sub-groove 122 are designed according to different positions and material properties, which is convenient for design, the calculation result is accurate, and the performance of the cover plate 110 is guaranteed.

[0115] See Figure 24 、 Figure 25 、 Figure 26 、 Figure 27 and Figure 28As shown in the figure, the embodiment of the present application further provides a battery. The battery 100 can be a cylindrical battery. The explosion-proof structure can be applied to the positive electrode side or the negative electrode side of the battery. Taking the application of the explosion-proof structure to the negative electrode side of the battery as an example for illustration. The battery includes the above-mentioned explosion-proof structure, a winding core 140, and a housing 150. The winding core 140 is installed in the housing 150. One end of the housing 150 is provided with an opening 151. A cover plate 110 is hermetically connected to the housing 150 to block the opening 151. The battery has the same technical effect as the battery explosion-proof structure, which will not be elaborated herein.

[0116] Based on the above embodiments, referring to Figure 27 and Figure 28 As shown in the figure, the battery further includes a first current collector plate 160, a second current collector plate 170, and an insulating member 180. The other end of the housing 150 is provided with a positive terminal 152. The winding core 140, the first current collector plate 160, and the second current collector plate 170 are all arranged in the housing 150. The cover plate 110 is hermetically connected to the housing 150 and blocks the opening 151. The second side surface 112 of the cover plate 110 abuts against one side surface of the first current collector plate 160. The other side surface of the first current collector plate 160 is welded to the negative electrode end of the winding core 140. The circumferential side of the first current collector plate 160 is connected to the inner surface of the housing 150, so that the housing 150 is electrified. There is no potential difference between the cover plate 110 and the housing 150, reducing the risk of corrosion of the cover plate 110 and improving the reliability of the battery. The positive terminal 152 is arranged at the end of the housing 150 away from the cover plate 110. The positive terminal 152 is hermetically connected to the housing 150 through an insulating sealing ring. The second current collector plate 170 is welded to the winding core 140 and the positive terminal 152 and is arranged between the positive electrode end of the winding core 140 and the positive terminal 152. In addition, an insulating member 180 is provided between the second current collector plate 170 and the end of the housing 150 to insulate the second current collector plate 170 and the housing 150. The first side surface 111 is the surface of the cover plate 110 facing away from the winding core 140, and the second side surface 112 is the surface of the cover plate 110 facing the winding core 140.

[0117] In some embodiments, the area of the outer circle formed by the explosion-proof groove 120 on the cover plate 110 is φ1. φ1 refers to the area calculated based on the outer diameter of the ring formed by the explosion-proof groove 120 on the cover plate 110. Along the direction perpendicular to the axis of the housing 150, the cross-sectional area of the housing 150 is φ2. Among them,

[0118]

[0119] It can be understood that The value of can be 0.27, 0.3, 0.4, 0.5, 0.6, 0.6, 0.6, 7.6 or other unlisted values. Reasonably setting the ratio of φ1 to φ2 ensures the pressure relief effect of the explosion-proof structure.

[0120] In some embodiments, a portion of the side wall of the shell 150 near the opening 151 shrinks inward to form a flange 153, and a pressure plate 154 is provided on the opening 151 of the shell 150. The pressure plate 154 and the flange 153 are relatively spaced apart. The cover 110 is installed between the flange 153 and the pressure plate 154. A seal 155 is provided between the cover 110 and the flange 153 and the pressure plate 154. The seal 155 is a sealing ring, and the compression rate of the sealing ring is 30% to 70%, which ensures the sealing of the cover 110 and improves the pressure relief effect of the explosion-proof structure.

[0121] In other embodiments, the cover plate 110 and the shell 150 are connected by laser welding. The laser welding process is simple and has good sealing. At this time, the first collecting plate 160 is in direct contact with the shell 150 and can also be in direct contact with the cover plate 110 to make the shell 150 negatively charged.

[0122] The present application also provides a battery pack, including the above-mentioned battery 100. The battery pack has the same technical effect as the battery explosion-proof structure, which will not be described in detail.

[0123] In some embodiments, see Figure 29 , Figure 30 and Figure 31 As shown, the battery pack further includes a mounting seat 130, the mounting seat 130 is provided with a plurality of mounting grooves 131 and a plurality of baffles 132, the battery, the mounting grooves 131 and the baffles 132 correspond one to one, the end of the battery 100 close to the cover plate 110 is mounted in the mounting groove 131, the baffle 132 is located on the side of the mounting groove 131 away from the battery 100, the first sub-groove 121 has a first groove wall 1211 and a second groove wall 1212, the second groove wall 1212 is closer to the center of the cover plate 110 than the first groove wall 1211, and the projection of the baffle 132 on one side of the cover plate 110 is located on the side of the first groove wall 1211 away from the second groove wall 1212. Among them, the baffle 132 can be a flat plate or an arc-shaped plate.

[0124] It can be understood that as the pressure in the battery 100 increases, the first sub-groove 121 in the sink 1141 opens, and the gas and substances in the battery 100 are ejected from the side of the first sub-groove 121. By setting a baffle 132 on the mounting base 130, the baffle 132 is located below the sink 1141, and the projection of the baffle 132 on the plane where the cover plate 110 is located is aligned with the first sub-groove 121. The baffle 132 has a large blocking area, and the baffle 132 blocks the substances ejected from the battery 100, thereby preventing the ejected substances from entering the adjacent battery 100 and contaminating the adjacent battery 100.

[0125] See also Figure 31It can be seen that the baffle 132 is an arc-shaped plate. The arc length of the baffle 132 is L4, and the arc length of the region where the first sub-slot 121 is located is L5. L4≥L5, so that the baffle 132 has a larger blocking area and better blocking effect.

[0126] Based on the above embodiments, refer to Figure 15 As shown, the mounting seat 130 includes a first sub-plate 133 and a second sub-plate 134. Along the thickness direction of the mounting seat 130, the first sub-plate 133 and the second sub-plate 134 are relatively spaced apart. The first sub-plate 133 is connected to the second sub-plate 134. The mounting groove 131 is opened on the first sub-plate 133. The baffle 132 is located between the first sub-plate 133 and the second sub-plate 134, and the baffle 132 is connected to the first sub-plate 133. The material flowing out after the cover plate 110 is opened flows between the first sub-plate 133 and the second sub-plate 134, avoiding affecting other batteries.

[0127] The technical solutions and technical effects of the present application will be described in detail below through specific embodiments and comparative examples. The following embodiments are only partial embodiments of the present application and do not specifically limit the present application.

[0128] This embodiment aims to investigate the influence of the explosion-proof structure applied to the battery on the battery performance.

[0129] The first test group

[0130] In this test group, the explosion-proof structure is: refer to Figure 1 As shown, the cover plate 110 includes a first side surface 111 and a second side surface 112 arranged opposite to each other. The first sub-slot 121 and the second sub-slot 122 are both arranged on the first side surface 111. The first sub-slot 121 and the second sub-slot 122 are both arc-shaped rings. The first sub-slot 121 and the second sub-slot 122 are connected end to end. The first sub-slot 121 and the second sub-slot 122 are communicated. The projections of the first sub-slot 121 and the second sub-slot 122 on one side surface of the cover plate 110 are arc-shaped. The parameters of the cover plate 110 involve H1, H2, H2 - H1, a, C, G, E1.

[0131] Test method: Adopt Article 6.2.4 of the standard GB / T31485-2015.

[0132] Evaluation criteria: The opening time of the first sub-slot 121 is T1, the opening time of the second sub-slot 122 is T2, and the opening time difference between the first sub-slot 121 and the second sub-slot 122 is ΔT. Among them, T1 and T2 meet the following conditions: 50s≤T1≤100s, 60s≤T2≤150s, 5s≤ΔT≤50s.

[0133] Set the basic group 1. The parameters and verification results of the basic group 1 are shown in Table 1.1 below.

[0134] Table 1.1: Parameters and verification results of basic group 1

[0135]

[0136]

[0137] According to the verification results in Table 1.1, the opening times of the first sub-slot 121 and the second sub-slot 122 both meet the evaluation criteria. While meeting the performance of the explosion-proof structure, secondary pressure relief is achieved.

[0138] Based on the parameters of basic group 1, by controlling the parameter changes of the cover plate 110 through the single-variable method, comparative examples and examples are set. The variable parameter tables and verification results of the comparative examples and examples are shown in Tables 1.2 to 1.5.

[0139] Table 1.2: Verification results of comparative examples and examples set by changing H1 and H2 accordingly with the parameters of basic group 1

[0140] H1 / μm H2 / μm Verification result Example 1 20.0 25.0 T1 = 60 s, T2 = 65 s, ΔT = 5 s Example 2 67.0 72.0 T1 = 75 s, T2 = 90 s, ΔT = 15 s Comparative example 1 15.0 20.0 T1 = 55 s, T2 = 59 s, ΔT = 4 s Comparative example 2 120.0 125.0 T1 = 118 s, T2 = 122 s, ΔT = 4 s

[0141] According to Table 1.2, when H1 is within the set range, while meeting the performance of the explosion-proof structure, secondary pressure relief is achieved. When H1 is not within the set range, the time interval between the two pressure relieves is short, resulting in a reduction in the secondary pressure relief effect of the explosion-proof structure.

[0142] Table 1.3: Verification results of comparative examples and examples set by changing H2 to achieve a change in H2 - H1 with the parameters of basic group 1

[0143] H2 / μm H2 - H1 / μm Verification result Example 1 125.0 10.0 T1 = 95 s, T2 = 125 s, ΔT = 30 s Example 2 135.0 20.0 T1 = 95 s, T2 = 143 s, ΔT = 48 s Comparative example 1 117.0 2.0 T1 = 95 s, T2 = 98 s, ΔT = 3 s Comparative example 2 140.0 25.0 T1 = 95 s, T2 > 150 s, ΔT > 45 s

[0144] According to Table 1.3, when H2 and H2 - H1 are within the set range, while meeting the performance of the explosion-proof structure, secondary pressure relief is achieved. When H2 - H1 is below the set range, the time interval between the two pressure relieves is short. When H2 - H1 is above the set range, the time interval between the two pressure relieves is long, or the opening time of the second sub-slot 122 is late, resulting in a reduction in the secondary pressure relief effect of the explosion-proof structure.

[0145] Table 1.4: Verification results of comparative examples and examples set by changing G with the parameters of basic group 1

[0146] G Verification result Example 1 1 / 10 T1 = 95 s, T2 = 127 s, ΔT = 32 s Example 2 1 / 7 T1 = 95 s, T2 = 136 s, ΔT = 41 s Comparative example 1 1 / 5 T1 = 96 s, T2 = 150 s, ΔT = 54 s Comparative example 2 1 / 22 T1 = 95 s, T2 = 98 s, ΔT = 3 s

[0147] According to Table 1.4, when G is within the set range, while meeting the performance of the explosion-proof structure, secondary pressure relief is achieved. When G is below the set range, the time interval between the two pressure relieves is long. When G is above the set range, the time interval between the two pressure relieves is short, resulting in a reduction in the secondary pressure relief effect of the explosion-proof structure.

[0148] Table 1.5: Verification Results of Comparative Examples and Examples with Basic Group 1 as Parameter and E1 Setting Changed

[0149]

[0150]

[0151] As can be seen from Table 1.5, when E1 is within the set range, while meeting the explosion-proof structure performance, secondary pressure relief is achieved. When E1 is lower or higher than the set range, the time interval between the two pressure reliefs is longer, and the secondary pressure relief effect of the explosion-proof structure is reduced.

[0152] Second Test Group

[0153] In this test group, the explosion-proof structure is as follows: Refer to Figure 2 As shown, the cover plate 110 includes a first side surface 111 and a second side surface 112 which are oppositely arranged. The first sub-groove 121 and the second sub-groove 122 are both arranged on the first side surface 111. The first sub-groove 121 and the second sub-groove 122 are both arc-shaped rings. The first sub-groove 121 and the second sub-groove 122 are connected end to end, and the first sub-groove 121 and the second sub-groove 122 are communicated. The cover plate 110 includes a first sub-part 113 and a second sub-part 114. The first sub-part 113 and the second sub-part 114 are adjacent. The first sub-part is close to the edge of the cover plate 110. In the direction from the second side surface 112 to the first side surface 111, the second sub-part 114 is higher than the first sub-part 113, and the explosion-proof groove 120 is arranged on the second sub-part 114. The parameters of the cover plate 110 involve H1, H2, H2 - H1, a, C, G, B, E1, E2, E3, E4, E3 - E2.

[0154] Test method: Adopt Article 6.2.4 of the standard GB / T31485 - 2015.

[0155] Evaluation criteria: The opening time of the first sub-groove 121 is T1, and the opening time of the second sub-groove 122 is T2. Among them, T1 and T2 meet the following conditions: 50s ≤ T1 ≤ 100s, 60 ≤ T2 ≤ 150s, 5s ≤ ΔT ≤ 50s.

[0156] Set Basic Group 2. The parameters and verification results of Basic Group 2 are shown in Table 2.1 below.

[0157] Table 2.1: Parameters and Verification Results of Basic Group 2

[0158]

[0159] According to the verification results in Table 2.1, it can be seen that the opening time of the first sub-groove 121 and the opening time of the second sub-groove 122 both meet the evaluation criteria, and while meeting the performance of the explosion-proof structure, secondary pressure relief is achieved.

[0160] According to the comparison of the verification results of the basic group 1 and the basic group 2, it can be seen that by setting the explosion-proof groove 120 on the second sub-part 114, on the premise of ensuring the battery safety performance, the interval difference between the two pressure relieves will be increased, and the secondary pressure relief effect of the explosion-proof structure will be improved.

[0161] Based on the parameters of the basic group 2, the parameters of the cover plate 110 are controlled to change by the single variable method to set the comparative example and the embodiment. The changed parameters and verification results of the comparative example and the embodiment are shown in Tables 2.2 to 2.3.

[0162] Table 2.2: Verification results of the comparative example and the embodiment with the parameters of the basic group 2 and the change of B

[0163]

[0164]

[0165] It can be seen from Table 2.2 that when B is within the set range, while meeting the performance of the explosion-proof structure, secondary pressure relief is achieved. When B is lower than or exceeds the set range, the time interval between the two pressure relieves is shorter, and the secondary pressure relief effect of the explosion-proof structure is reduced.

[0166] Table 2.3: Verification results of the comparative example and the embodiment with the parameters of the basic group 2 and the change of E1, E2, and E3

[0167]

[0168] It can be seen from Table 2.2 that when E1, E2, E3, and (E3 - E2) are all within the set range, while meeting the performance of the explosion-proof structure, secondary pressure relief is achieved. When E2 is not within the set range, the time interval between the two pressure relieves is shorter, and the secondary pressure relief effect of the explosion-proof structure is reduced.

[0169] The third test group

[0170] The explosion-proof structure in this test group is: See Figure 3As shown in the figure, the cover plate 110 includes a first side surface 111 and a second side surface 112 that are oppositely arranged. The first sub-groove 121 and the second sub-groove 122 are both arranged on the first side surface 111. The first sub-groove 121 and the second sub-groove 122 are both arc-shaped rings. The first sub-groove 121 is connected end to end with the second sub-groove 122, and the first sub-groove 121 communicates with the second sub-groove 122. The cover plate 110 includes a first sub-part 113 and a second sub-part 114. The first sub-part 113 is adjacent to the second sub-part 114. The first sub-part is close to the edge of the cover plate 110. In the direction from the second side surface 112 to the first side surface 111, at least part of the surface of the second sub-part 114 facing the core 140 is higher than the surface of the first sub-part 113 facing the core 140, and at least part of the surface of the second sub-part 114 away from the core 140 is higher than the surface of the first sub-part 113 away from the core 140. The explosion-proof groove 120 is arranged on the second sub-part 114. The second sub-part 114 includes a connected sink 1141 and a boss 1142. The sink 1141 and the boss 1142 enclose a closed ring. The surface of the boss 1142 facing the core 140 is higher than the surface of the sink 1141 facing the core 140 and the surface of the first sub-part 113 facing the core 140. The surface of the boss 1142 facing away from the core 140 is higher than the surface of the sink 1141 facing away from the core 140 and the surface of the first sub-part 113 facing away from the core 140. At least part of the first sub-groove 121 is arranged on the sink 1141, and at least part of the second sub-groove 122 is located on the boss 1142. The parameters of the cover plate 110 involve H1, H2, H2 - H1, a, C, G, A, E1, E2, E3, E4, E3 - E2, D1, D2, and α.

[0171] Test method: Adopt Article 6.2.4 of the GB / T31485 - 2015 standard.

[0172] Evaluation criteria: The opening time of the first sub-groove 121 is T1, and the opening time of the second sub-groove 122 is T2. Among them, T1 and T2 meet the following conditions: 50s ≤ T1 ≤ 100s, 60s ≤ T2 ≤ 150s, 15s ≤ ΔT ≤ 50s.

[0173] Set the basic group 3. The parameters and verification results of the basic group 3 are shown in Table 3.1 below.

[0174] Table 3.1: Parameters of the basic group 3

[0175]

[0176]

[0177] According to the verification results in Table 3.1, the opening time of the first sub-groove 121 and the opening time of the second sub-groove 122 both meet the evaluation criteria. While meeting the performance of the explosion-proof structure, secondary pressure relief is achieved.

[0178] According to the comparison of the verification results of basic group 1, basic group 2, and basic group 3, it can be seen that a sinking platform 1141 and a convex platform 1142 are provided on the second sub-portion 114. On the premise of ensuring the battery safety performance, the time interval between the first pressure relief and the second pressure relief is longer, the secondary pressure relief effect is good, and the reliability of the explosion-proof structure is further improved.

[0179] Based on the parameters of basic group 3, the parameters of the cover plate 110 are controlled to change by the single-variable method to set the comparative example and the embodiment. The changed parameters and verification results of the comparative example and the embodiment are shown in Table 3.2.

[0180] Table 3.2: Verification results of the comparative example and the embodiment set by changing D1 and D2 changing with D1 based on basic group 3

[0181] D1 / mm D2 / mm Verification result Example 1 4.00 3.20 T1 = 74 s, T2 = 122 s, ΔT = 48 s Example 2 12.00 11.20 T1 = 97 s, T2 = 126 s, ΔT = 29 s Comparative example 1 1.00 0.20 T1 = 60 s, T2 = 124 s, ΔT = 64 s Comparative example 2 18.00 17.20 T1 = 100 s, T2 = 104 s, ΔT = 4 s

[0182] According to Table 3.1: When D1 is within the set range, while meeting the performance of the explosion-proof structure, secondary pressure relief is achieved. When D1 is lower than the set range, the time interval between the two pressure relieves is longer. When D1 exceeds the set range, the time interval between the two pressure relieves is shorter, and the secondary pressure relief effect of the explosion-proof structure is reduced.

[0183] Fourth test group

[0184] The structure of the battery explosion-proof structure in this test group is as follows: Refer to Figure 14 As shown, a first sub-groove 121 and a second sub-groove 122 are provided on the first side surface 111 of the cover plate 110. The first sub-groove 121 includes a first section 1111, a second section 1112, and a third section 1117. The first section 1111, the second section 1112, and the third section 1117 are all arc-shaped. The second sub-groove 122 is circular. Along the radial direction of the cover plate 110, the first sub-groove 121 is closer to the center of the cover plate 110 than the second sub-groove 122.

[0185] Test method: Adopt Article 6.2.4 of the standard GB / T31485-2015.

[0186] Evaluation criteria: The opening time of the first sub-groove 121 is T1, the opening time of the second sub-groove 122 is T2, and the time difference between the opening of the first sub-groove 121 and the second sub-groove 122 is ΔT. Among them, T1 and T2 meet the following conditions: 50s ≤ T1 ≤ 100s, 60s ≤ T2 ≤ 150s, and the time 5s ≤ ΔT ≤ 50s.

[0187] The parameters related to the cover plate 110 include: H1, H2, H2 - H1, a, C, E1, L1, L2, L3, β. L1 and L2 are the same. The parameters of basic group 4 are shown in Table 4.1 below.

[0188] Table 4.1: Parameters of Basic Group 4 and Verification Results

[0189]

[0190] According to the verification results in Table 4.1, the opening times of the first sub-slot 121 and the second sub-slot 122 both meet the evaluation criteria. While meeting the performance of the explosion-proof structure, secondary pressure relief is achieved.

[0191] Based on the parameters of Basic Group 4, by controlling the parameter changes of the cover plate 110 through the single-variable method, the comparative examples and embodiments are set. The variable parameter tables and verification results of the comparative examples and embodiments are shown in Tables 4.2 to 4.7.

[0192] Table 4.2: Verification Results of Comparative Examples and Embodiments Set by Changing H1 and Subsequently Changing H2 Based on Basic Group 4

[0193] H1 / μm H2 / μm Verification result Example 1 20.00 25.00 T1 = 50 s, T2 = 60 s, ΔT = 10 s Example 2 67.00 72.00 T1 = 76 s, T2 = 87 s, ΔT = 11 s Comparative example 1 15.00 20.00 T1 = 43 s, T2 = 48 s, ΔT = 5 s Comparative example 2 120.00 125.00 T1 = 126 s, T2 = 130 s, ΔT = 4 s

[0194] According to Table 4.2, when H1 is within the set range, while meeting the performance of the explosion-proof structure, secondary pressure relief is achieved. When H1 is lower than the set range, the opening times of the first-stage pressure relief and the second-stage pressure relief are both earlier. When H1 exceeds the set range, the time interval between the two pressure reliefs is shorter, and the secondary pressure relief effect of the explosion-proof structure is not good.

[0195] Table 4.3: Verification Results of Comparative Examples and Embodiments Set by Changing H2 to Achieve a Change in H2 - H1 with Basic Group 4 as Parameters

[0196] H2 / μm H2 - H1 / μm Verification result Example 1 125.00 10.00 T1 = 96 s, T2 = 132 s, ΔT = 36 s Example 2 135.00 20.00 T1 = 96 s, T2 = 139 s, ΔT = 43 s Comparative example 1 117.00 2.00 T1 = 97 s, T2 = 101 s, ΔT = 4 s Comparative example 2 140.00 25.00 T1 = 95 s, T2 = 153 s, ΔT = 58 s

[0197] According to Table 4.3, when H2 - H1 is within the set range, while meeting the performance of the explosion-proof structure, secondary pressure relief is achieved. When H2 - H1 is lower than or within the set range, the time interval between the two pressure reliefs is shorter. When H2 - H1 exceeds the set range, the time interval between the two pressure reliefs is too long, resulting in an increased probability of battery explosion and a reduction in the secondary pressure relief effect of the explosion-proof structure.

[0198] Table 4.4: Verification Results of Comparative Examples and Embodiments Set by Changing L3 with Basic Group 4 as Parameters

[0199] L3 / mm Verification results Example 1 1.00 T1 = 90s, T2 = 123s, ΔT = 33s Example 2 3.00 T1 = 86s, T2 = 126s, ΔT = 40s Comparative Example 1 0.50 T1 = 119s, T2 = 123s, ΔT = 4s Comparative Example 2 4.00 T1 = 70s, T2 = 125s, ΔT = 55s

[0200] According to Table 4.4, when L3 is within the set range, while meeting the performance of the explosion-proof structure, secondary pressure relief is achieved. When L3 is lower than the set range, the time interval between the two pressure reliefs is shorter. When L3 exceeds the set range, the time interval between the two pressure reliefs is longer, resulting in a reduction in the secondary pressure relief effect of the explosion-proof structure.

[0201] Table 4.5: Verification results of comparative examples and examples with the basic group 4 as the parameter and the settings of L1 and L2 changed

[0202] L1 and L2 / mm Verification results Example 1 4.00 T1 = 93s, T2 = 124s, ΔT = 31s Example 2 8.00 T1 = 97s, T2 = 126s, ΔT = 29s Comparative Example 1 1.00 T1 = 84s, T2 = 136s, ΔT = 52s Comparative Example 2 15.00 T1 = 100s, T2 = 104s, ΔT = 4s

[0203] As can be seen from Table 4.5, when L1 and L2 are within the set range, while meeting the performance of the explosion-proof structure, secondary pressure relief is achieved. When L1 and L2 are lower than the set range, the time interval between the two pressure reliefs is too long. When L1 and L2 exceed the set range, the time interval between the two pressure reliefs is short, resulting in a reduction in the secondary pressure relief effect of the explosion-proof structure.

[0204] Table 4.6: Verification results of comparative examples and examples with the basic group 4 as the parameter and the setting of β changed

[0205] β Verification results Example 1 30° T1 = 100s, T2 = 127s, ΔT = 27s Example 2 150° T1 = 93s, T2 = 122s, ΔT = 29s Comparative Example 1 20° T1 = 111s, T2 = 114s, ΔT = 3s Comparative Example 2 170° T1 = 76s, T2 = 132s, ΔT = 56s

[0206] As can be seen from Table 4.6, when β is within the set range, while meeting the performance of the explosion-proof structure, secondary pressure relief is achieved. When β is lower than the set range, the time interval between the two pressure reliefs is short. When β exceeds the set range, the time interval between the two pressure reliefs is long, resulting in a reduction in the secondary pressure relief effect of the explosion-proof structure.

[0207] The fifth test group

[0208] In this test group, the structure of the battery explosion-proof structure is as follows: Refer to Figure 18 As shown, a first sub-groove 121 and a second sub-groove 122 are provided on the first side surface 111 of the cover plate 110. The first sub-groove 121 includes a first section 1111, a second section 1112, and a third section 1117. The first section 1111, the second section 1112, and the third section 1117 are all arc-shaped. The second sub-groove 122 is circular. Along the radial direction of the cover plate 110, the first sub-groove 121 is closer to the center of the cover plate 110 than the second sub-groove 122. The cover plate 110 includes a first sub-part 113 and a second sub-part 114. The surface of the second sub-part 114 away from the winding core 140 is higher than the surface of the first sub-part 113 away from the winding core 140. The surface of the second sub-part 114 facing the winding core 140 is higher than the surface of the first sub-part 113 facing the winding core 140. The first sub-groove 121 and the second sub-groove 122 are both provided on the second sub-part 114.

[0209] Test method: Adopt Article 6.2.4 of the standard GB / T31485-2015.

[0210] Evaluation criteria: The opening time of the first sub-groove 121 is T1, the opening time of the second sub-groove 122 is T2, and the time interval between the openings of the first sub-groove 121 and the second sub-groove 122 is ΔT. Among them, T1 and T2 meet the following conditions: 50s ≤ T1 ≤ 100s, 60s ≤ T2 ≤ 150s, 5s ≤ ΔT ≤ 50s.

[0211] The parameters related to the cover plate 110 include: H1, H2, H2 - H1, a, C, L1, L2, L3, β, and E1. The basic group 5 is set, and the parameters and verification results of the basic group 5 are shown in Table 5.1.

[0212] Table 5.1: Parameters and verification results of basic group 5

[0213]

[0214]

[0215] According to the verification results in Table 5.1, the opening time of the first sub - slot 121 and the opening time of the second sub - slot 122 both meet the evaluation criteria. While meeting the performance of the explosion - proof structure, secondary pressure relief is achieved.

[0216] Based on the parameters of the basic group 5, by controlling the parameter changes of the cover plate 110 through the single - variable method, the comparative examples and examples are set. The changed parameters and verification results of the comparative examples and examples are shown in Table 5.2.

[0217] Table 5.2: Verification results of comparative examples and examples with the parameters of basic group 5 and B changed

[0218] B / mm Verification results Example 1 0.48 T1 = 89s, T2 = 119s, ΔT = 30s Example 2 0.60 T1 = 87s, T2 = 121s, ΔT = 34s Comparative Example 1 0.20 T1 = 95s, T2 = 98s, ΔT = 3s Comparative Example 2 1.00 T1 = 68s, T2 = 125s, ΔT = 57s

[0219] According to Table 5.2, when B is within the set range, the purpose of secondary pressure relief can be achieved. When B is lower than the set range, the time interval between the two pressure relieves is shorter. When B exceeds the set range, the time interval between the two pressure relieves is longer, resulting in a reduction in the secondary pressure - relief effect of the explosion - proof structure.

[0220] The sixth test group

[0221] The explosion - proof structure in this test group is: Refer to Figure 12As shown, the cover plate 110 includes a first side surface 111 and a second side surface 112 that are oppositely arranged, a first sub-groove 121 and a second sub-groove 122 that are both arranged on the first side surface 111, and both the first sub-groove 121 and the second sub-groove 122 are arc-shaped circular rings, the first sub-groove 121 and the second sub-groove 122 are connected end to end, and the first sub-groove 121 and the second sub-groove 122 are in communication. The cover plate 110 includes a first sub-portion 113 and a second sub-portion 114, the first sub-portion 113 and the second sub-portion 114 are adjacent, the first sub-portion is close to the edge of the cover plate 110, and points from the second side surface 112 to the direction of the first side surface 111, the surface of the second sub-portion 114 away from the winding core 140 is at least partially higher than the surface of the first sub-portion 113 away from the winding core 140, and the surface of the second sub-portion 114 facing the winding core 140 is at least partially higher than the surface of the first sub-portion 113 facing the winding core 140, and the explosion-proof groove 120 is arranged on the second sub-portion 114. The second sub-section 114 is connected to a sink 1141 and a boss 1142, and the sink 1141 and the boss 1142 form a closed ring. The second sub-section 114 includes a connected sink 1141 and a boss 1142. The surface of the boss 1142 facing the winding core 140 is higher than the surface of the sink 1141 facing the winding core 140 and the surface of the first sub-section 113 facing the winding core 140. The surface of the boss 1142 facing away from the winding core 140 is higher than the surface of the sink 1141 facing away from the winding core 140 and the surface of the first sub-section 113 facing away from the winding core 140. The first sub-groove 121 is at least partially arranged on the sink 1141, and the second sub-groove 122 is at least partially located on the boss 1142.

[0222] The parameters of the cover plate 110 involve H1, H2, E1, H2-H1, a, C, L1, L2, L3, β, A, D1, D2 and α.

[0223] Set basic group 6. The parameters of basic group 6 are shown in 6.1 below.

[0224] Table 6.1: Parameters and verification results of basic group 6

[0225]

[0226]

[0227] According to the verification results in Table 6.1, the opening time of the first sub-groove 121 and the opening time of the second sub-groove 122 both meet the evaluation criteria, meeting the performance of the explosion-proof structure while achieving secondary pressure relief.

[0228] According to the verification structure of basic group 5 and basic group 6, it can be known that a sink 1141 and a boss 1142 are set on the second sub-section 114. Under the premise of ensuring the safety performance of the battery, the time interval between the primary pressure relief and the secondary pressure relief is longer, the secondary pressure relief effect is good, and the reliability of the explosion-proof structure is further improved.

[0229] Based on the parameters of the basic group 6, the parameter changes of the cover plate 110 are controlled by the single variable method to set the comparative examples and the examples. The changed parameters and verification results of the comparative examples and the examples are shown in Table 6.2.

[0230] Table 6.2: Verification results of comparative examples and examples with D1 and D2 changed based on the basic group 6 and D1 changed

[0231] D1 D2 / mm Verification results Example 1 4.00 3.20 T1 = 86s, T2 = 120s, ΔT = 34s Example 2 12.00 11.20 T1 = 90s, T2 = 110s, ΔT = 20s Comparative Example 1 1.00 0.20 T1 = 72s, T2 = 136s, ΔT = 64s Comparative Example 2 18.00 17.20 T1 = 103s, T2 = 106s, ΔT = 3s

[0232] According to Table 6.2: When D1 is within the set range, the purpose of secondary pressure relief can be achieved and the secondary pressure relief effect is good. When D1 is lower than the set range, the interval time between two pressure relieves is longer. When D1 exceeds the set range, the interval time between two pressure relieves is also longer, resulting in a reduction in the secondary pressure relief effect of the explosion-proof structure.

Claims

1. An explosion-proof structure, applied to a battery, characterized in that: include: A cover plate (110); An explosion-proof groove (120) is arranged on the cover plate (110), and the explosion-proof groove (120) comprises a first sub-groove (121) and a second sub-groove (122). The thickness of the cover plate (110) at the position where the first sub-groove (121) is located is H1, and the thickness of the cover plate at the position where the second sub-groove (122) is located is H2, H1<H2, wherein, under a first pressure, the cover plate (110) at the first sub-groove (121) is opened, and under a second pressure, the cover plate (110) at the second sub-groove (122) is opened, the first pressure is P1, 0.5Mpa<P1<1.5Mpa, and the second pressure is P2, 1.5Mpa≤P2<2.5Mpa.

2. The explosion-proof structure according to claim 1, characterized in that: The projections of the first sub-groove (121) and the second sub-groove (122) on a side surface of the cover plate (110) form a closed circular ring.

3. The explosion-proof structure according to claim 1, characterized in that: The first sub-groove (121) comprises a first section (1111) and a second section (1112), the first section (1111) having a first end (1113) and a second end (1114), the second section (1112) having a third end (1115) and a fourth end (1116), and the distance between the first end (1113) and the third end (1115) is greater than the distance between the second end (1114) and the fourth end (1116).

4. The explosion-proof structure according to claim 3, characterized in that: The first sub-groove (121) and the second sub-groove (122) are arranged at an interval, and the first sub-groove (121) is closer to the center of the cover plate (110) than the second sub-groove (122).

5. The explosion-proof structure according to claim 3, characterized in that: The second sub-groove (122) is arc-shaped, and the second sub-groove (122) comprises a fifth end (1121) and a sixth end (1122), and the second sub-groove (122) is located between the fifth end (1121) and the sixth end (1122).

6. The explosion-proof structure according to claim 5, characterized in that: The first end (1113) is connected to the fifth end (1121), the third end (1115) is connected to the sixth end (1122), and the first sub-groove (121) is connected to the second sub-groove (122) to form a closed shape.

7. The explosion-proof structure according to claim 3, characterized in that: The second end (1114) is closer to the center of the cover plate (110) than the first end (1113), and the fourth end (1116) is closer to the center of the cover plate (110) than the third end (1115); Alternatively, the first end (1113) is closer to the center of the cover plate (110) than the second end (1114), and the third end (1115) is closer to the center of the cover plate (110) than the fourth end (1116).

8. The explosion-proof structure according to claim 3, characterized in that: The first sub-groove (121) further comprises a third section (1117), wherein the third section (1117) is arranged between the second end (1114) and the fourth end (1116), and the third section (1117) smoothly transitions and connects the first section (1111) and the second section (1112).

9. The explosion-proof structure according to claim 8, characterized in that: The first section (1111), the second section (1112) and the third section (1117) are all arc-shaped, and the bending direction of the first section (1111) and the second section (1112) is different from the bending direction of the third section (1117).

10. The explosion-proof structure according to claim 9, characterized in that: An angle β is formed between the chord corresponding to the arc of the first section (1111) and the chord corresponding to the arc of the second section (1112), wherein 30°≤β≤150°.

11. The explosion-proof structure according to claim 9, characterized in that: The arc length of the first section (1111) is L1, the arc length of the second section (1112) is L2, and the arc length of the third section (1117) is L3, 4mm≤L1=L2≤8mm, 1mm≤L3≤3mm.

12. The explosion-proof structure according to any one of claims 1 to 11, characterized in that: 20μm≤H1≤115μm, 25μm≤H2≤135μm.

13. The explosion-proof structure according to any one of claims 1 to 11, characterized in that: 5μm≤H2-H1≤20μm.

14. The explosion-proof structure according to any one of claims 1 to 11, characterized in that: The thickness H2 of the cover plate (110) at the second sub-groove (122) is calculated according to the following formula (1): Wherein, Q is the tensile strength of the material used to make the cover plate (110); E1 is the outer diameter of the ring where the second sub-groove (122) is located; P2 is the pressure at which the cover plate (110) at the second sub-groove (122) opens.

15. The explosion-proof structure according to claim 2, characterized in that: The thickness H1 of the cover plate (110) at the first sub-groove (121) is calculated according to the following formula (2): Wherein, Q is the tensile strength of the material used to make the cover plate (110); E1 is the outer diameter of the circular ring where the second sub-groove (122) is located, and the outer diameters of the first sub-groove (121) and the second sub-groove (122) are the same; P1 is the pressure at which the cover plate (110) at the first sub-groove (121) opens.

16. The explosion-proof structure according to claim 2, characterized in that: The ratio of the arc length of the first sub-groove (121) to the arc length of the second sub-groove (122) is G, 17. The explosion-proof structure according to any one of claims 1 to 11, characterized in that: The cover plate (110) comprises a first sub-portion (113) and a second sub-portion (114); the first sub-portion (113) and the second sub-portion (114) are adjacent to each other; the first sub-portion (113) is close to the edge of the cover plate (110); at least a portion of the surface of the second sub-portion (114) facing the winding core (140) is higher than a surface of the first sub-portion (113) facing the winding core (140); at least a portion of the surface of the second sub-portion (114) away from the winding core (140) is higher than a surface of the first sub-portion (113) away from the winding core (140); and the explosion-proof groove (120) is arranged on the second sub-portion (114).

18. The explosion-proof structure according to claim 17, characterized in that: The second sub-portion (114) includes a connected sink (1141) and a boss (1142); the surface of the boss (1142) facing the core (140) is higher than the surface of the sink (1141) facing the core (140) and the surface of the first sub-portion (113) facing the core (140); the surface of the boss (1142) facing away from the core (140) is higher than the surface of the sink (1141) facing away from the core (140) and the surface of the first sub-portion (113) facing away from the core (140); the first sub-groove (121) is at least partially arranged on the sink (1141), and the second sub-groove (122) is at least partially located on the boss (1142).

19. The explosion-proof structure according to claim 18, characterized in that: The cover plate (110) further comprises a third sub-portion (115), the third sub-portion (115) is circular, the third sub-portion (115) is arranged concentrically with the second sub-portion (114), and the sink (1141) and the convex platform (1142) form a closed ring.

20. The explosion-proof structure according to claim 19, characterized in that: The cover plate (110) further comprises a fourth sub-portion (116), the fourth sub-portion (116) being annular and located between the second sub-portion (114) and the third sub-portion (115), and the fourth sub-portion (116) connecting the second sub-portion (114) and the third sub-portion (115).

21. The explosion-proof structure according to claim 20, characterized in that: The surface of the first sub-portion (113) facing the winding core (140) is higher than the surface of the fourth sub-portion (116) facing the winding core (140), and the fourth sub-portion (116) is used to connect to the electrode of the battery; Alternatively, the surface of the first sub-portion (113) facing the winding core (140), the surface of the fourth sub-portion (116) facing the winding core (140), and the surface of the sink (1141) facing the winding core (140) are located at the same height.

22. The explosion-proof structure according to claim 19, characterized in that: The surface of the third sub-portion (115) facing the winding core (140) is not lower than the surface of the boss (1142) facing the winding core (140), and the surface of the third sub-portion (115) away from the winding core (140) is not lower than the surface of the boss (1142) away from the winding core (140).

23. The explosion-proof structure according to claim 18, characterized in that: The width of the top of the sink (1141) is D1, and the width of the bottom of the sink (1141) is D2, wherein 4 mm ≤ D1 ≤ 12 mm; D2=D1-2C*tan(α-90°), and D2>2mm; α is the angle formed between the bottom and the side of the sink (1141), 100°≤α≤170°; C is the thickness of the area outside the explosion-proof groove (120) on the cover plate (110).

24. The explosion-proof structure according to claim 18, characterized in that: The depth of the sink (1141) is A, 0.8C≤A≤1.5C, wherein C is the thickness of the area outside the explosion-proof groove (120) on the cover plate (110).

25. The explosion-proof structure according to claim 18, characterized in that: The inner diameter of the second sub-section (114) is E2, the outer diameter of the second sub-section (114) is E3, the diameter of the cover plate (110) is E4, and the thickness of the area outside the explosion-proof groove (120) on the cover plate (110) is C, wherein: 42mm≤E4≤46mm; 0.75E4≤E3≤0.96E4, 0.4E4≤E2≤0.72E4 and 3C≤E3-E2≤27.8C.

26. The explosion-proof structure according to claim 18, characterized in that: The outer diameter of the circular ring where the second sub-groove (122) is located is E1, and E2+C≤E1≤E3-C.

27. The explosion-proof structure according to any one of claims 1 to 11, characterized in that: The thickness of the area outside the explosion-proof groove (120) on the cover plate (110) is C, 0.4 mm≤C≤1.0 mm.

28. The explosion-proof structure according to any one of claims 1 to 11, characterized in that: The slot width of the first sub-slot (121) and the slot width of the second sub-slot (122) are the same as a, wherein 0.6 mm ≤ a ≤ 1.5 mm.

29. The explosion-proof structure according to any one of claims 1 to 11, characterized in that: Along the thickness direction of the cover plate (110), the cross-sectional shape of the first sub-groove (121) and / or the second sub-groove (122) is V-shaped, semicircular, trapezoidal, "U"-shaped or parabolic.

30. The explosion-proof structure according to any one of claims 1 to 11, characterized in that: The cover plate (110) comprises a first side surface (111) and a second side surface (112) which are arranged opposite to each other, and the first sub-groove (121) and the second sub-groove (122) are both arranged on the first side surface (111); Alternatively, the cover plate (110) comprises a first side surface (111) and a second side surface (112) that are arranged opposite to each other, and the first sub-groove (121) and the second sub-groove (122) are both arranged on the second side surface (112); Alternatively, the cover plate (110) comprises a first side surface (111) and a second side surface (112) that are arranged opposite to each other, the first sub-groove (121) is arranged on the first side surface (111), and the second sub-groove (122) is arranged on the second side surface (112); Alternatively, the cover plate (110) comprises a first side surface (111) and a second side surface (112) which are arranged opposite to each other, the first sub-groove (121) is arranged on the second side surface (112), and the second sub-groove (122) is arranged on the first side surface (111).

31. A battery, characterized in that: include: The explosion-proof structure according to any one of claims 1 to 30; Roll core (140); A shell (150), the winding core (140) is installed in the shell (150), one end of the shell (150) is provided with an opening (151), and the cover plate (110) is sealedly connected to the shell (150) to block the opening (151).

32. The battery according to claim 31, characterized in that The invention also includes a positive terminal (152), a first current collecting disk (160), a second current collecting disk (170) and an insulating member (180); the positive terminal (152) is arranged at one end of the shell (150) away from the cover plate (110); the first current collecting disk (160) is welded to the winding core (140) and is arranged between the cover plate (110) and one end of the winding core (140); the second current collecting disk (170) is welded to the winding core (140) and the positive terminal (152) and is arranged between the winding core (140) and the positive terminal (152); and the insulating member (180) is arranged between the second current collecting disk (170) and the shell (150).

33. A battery pack, characterized in that: Comprising a battery as claimed in claim 31 or 32.

34. The battery pack according to claim 33, characterized in that: Also includes: The mounting seat (130) is provided with a plurality of mounting grooves (131) and a plurality of baffles (132); one end of the battery close to the cover plate (110) is mounted in the mounting groove (131); the baffle (132) is located on a side of the mounting groove (131) away from the battery; the first sub-groove (121) has a first groove wall (1211) and a second groove wall (1212); the second groove wall (1212) is closer to the center of the cover plate (110) than the first groove wall (1211); and the projection of the baffle (132) on a side of the cover plate (110) is located on a side of the first groove wall (1211) away from the second groove wall (1212).

35. The battery pack according to claim 34, characterized in that: The mounting seat (130) comprises a first sub-plate (133) and a second sub-plate (134), wherein the first sub-plate (133) and the second sub-plate (134) are arranged relatively spaced apart, the mounting groove (131) is provided on the first sub-plate (133), the baffle plate (132) is located between the first sub-plate (133) and the second sub-plate (134), and the baffle plate (132) is connected to the first sub-plate (133).

Images