Explosion-proof structure, and battery

Abstract

The present application discloses an explosion-proof structure, and a battery. The explosion-proof structure comprises a cover plate. An explosion-proof groove is formed on the cover plate. The explosion-proof groove comprises a first sub-groove and a second sub-groove. The projections of the first sub-groove and the second sub-groove on one side face of the cover plate define a closed circular ring. The thickness of the cover plate at the position of the first sub-groove is smaller than the thickness of the cover plate at the position of the second sub-groove. The present application improves the reliability of the cover plate, and ensures the explosion-proof effect.

Description

Explosion-proof structure and battery Technical Field

[0001] The present application belongs to the field of battery technology, and in particular relates to an explosion-proof structure and a battery. Background Art

[0002] During use, power batteries may experience internal pressure buildup due to short circuits or other factors, exceeding safety limits and potentially causing explosions. To minimize these risks, an explosion-proof diaphragm is typically installed on the battery cover. This diaphragm gradually deforms as internal pressure increases until it opens.

[0003] During the thermal runaway 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, combustion-supporting gases such as oxygen will also decompose inside the battery. When the internal pressure of the battery increases further, the explosion-proof diaphragm will burst. At the moment the explosion-proof valve bursts, the combustible gas, combustion-supporting gas and substances in the battery interact with each other, aggravating the degree of thermal runaway and easily causing the battery to explode. Technical issues

[0004] The embodiments of the present application provide an explosion-proof structure and a battery to solve the problem that when the explosion-proof structure of the related art explodes, the combustible gas, the combustion-supporting gas and the substances in the battery interact, aggravating the degree of thermal runaway and causing battery explosion. Technical Solutions

[0005] In the first aspect, an embodiment of the present application provides an explosion-proof structure, which is applied to a battery, including a cover plate, on which an explosion-proof groove is provided, and the explosion-proof groove includes a first sub-groove and a second sub-groove, and the projections of the first sub-groove and the second sub-groove on one side of the cover plate form a closed circular ring, and 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.

[0006] In a second aspect, an embodiment of the present application further provides a battery, comprising: the explosion-proof structure described above;

[0007] A winding core, including a positive terminal and a negative terminal;

[0008] The shell is provided with an opening at one end of the shell, and the cover is sealed with the shell to block the opening. Beneficial effects

[0009] The beneficial effects of the present application are as follows: the explosion-proof structure and battery provided by the embodiment of the present application, by arranging a first sub-groove and a second sub-groove on the cover plate, 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 is opened first, and the position of the second sub-groove on the cover plate is opened again, forming a secondary pressure relief of the battery, the first opening can discharge the combustible gas, and the second opening can discharge the combustion-supporting gas, thereby achieving the purpose of time-sharing discharge of the combustible gas and the combustion-supporting gas, overcoming the problem that when the explosion-proof structure of the related art explodes, the combustible gas, the combustion-supporting gas and the substances in the battery interact, aggravating the degree of thermal runaway and causing battery explosion, the projections of the first sub-groove and the second sub-groove on one side of the cover plate form a closed circle, ensuring the pressure relief area while, after the cover plate at the position of the first sub-groove is opened, the cover plate at the position of the second sub-groove is broken through from the connection between the first sub-groove and the second sub-groove, which is conducive to the opening of the cover plate at the position of the second sub-groove, improving the reliability of the cover plate, and ensuring the explosion-proof effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG1 is a top view of a first form of explosion-proof structure provided in an embodiment of the present application.

[0011] FIG2 is a cross-sectional view taken along line AA in FIG1 .

[0012] FIG3 is a partial enlarged view of point B in FIG1 .

[0013] FIG4 is a CC cross-sectional view in FIG3 .

[0014] FIG5 is a partial enlarged view of point D in FIG4 .

[0015] FIG6 is a cross-sectional view taken along line EE in FIG3 .

[0016] FIG7 is a marked diagram of the explosion-proof structure provided in an embodiment of the present application.

[0017] FIG8 is a three-dimensional diagram of an explosion-proof structure provided in an embodiment of the present application.

[0018] FIG9 is a top view of a second form of explosion-proof structure provided in an embodiment of the present application.

[0019] FIG10 is a top view of a third form of explosion-proof structure provided in an embodiment of the present application.

[0020] FIG11 is a top view of a fourth form of explosion-proof structure provided in an embodiment of the present application.

[0021] FIG12 is a top view of the fifth form of the explosion-proof structure provided in an embodiment of the present application.

[0022] FIG13 is a top view of the sixth form of the explosion-proof structure provided in an embodiment of the present application.

[0023] FIG14 is a three-dimensional diagram of a battery provided in an embodiment of the present application.

[0024] FIG15 is a top view of a battery provided in an embodiment of the present application.

[0025] FIG16 is a cross-sectional view of GG in FIG15 .

[0026] FIG17 is a partial enlarged view of point H in FIG16 .

[0027] FIG18 is a partial enlarged view of point M in FIG16 .

[0028] Explanation of the accompanying drawings: 110, cover plate; 111, first side; 112, second side; 113, first sub-section; 114, second sub-section; 1141, sink; 1142, boss; 115, third sub-section; 116, fourth sub-section; 120, explosion-proof groove; 121, first sub-groove; 122, second sub-groove; 140, winding core; 150, shell; 151, opening; 152, positive terminal; 153, flange; 154, pressure plate; 155, seal; 160, first collecting disc; 170, second collecting disc; 180, insulating member. Modes for Carrying Out the Invention

[0029] The present invention provides an explosion-proof structure and battery to address the problem in related art where, when an explosion-proof structure explodes, the combustible gas, the combustion-supporting gas, and the substances within the battery interact, exacerbating thermal runaway and causing battery explosion. This will be described below with reference to the accompanying drawings.

[0030] Referring to Figures 1 and 9 to 13, Figure 1 is a top view of the first form of the explosion-proof structure provided in an embodiment of the present application, Figure 9 is a top view of the second form of the explosion-proof structure provided in an embodiment of the present application, Figure 10 is a top view of the third form of the explosion-proof structure provided in an embodiment of the present application, Figure 11 is a top view of the fourth form of the explosion-proof structure provided in an embodiment of the present application, Figure 12 is a top view of the fifth form of the explosion-proof structure provided in an embodiment of the present application, and Figure 13 is a top view of the sixth form of the explosion-proof structure provided in an embodiment of the present application.

[0031] An explosion-proof structure is applied to batteries, such as cylindrical batteries. The explosion-proof structure includes a cover plate 110. The cover plate 110 is a disc-shaped structure. The material of the cover plate 110 can be steel, such as SPCC material, stainless steel materials SUS410, SUS306, SUS316, SUS430, SUS444, etc. When SPCC material is used, nickel can be plated on both sides of the cover plate 110. The thickness of the coating is 0.3μm to 8μm. The coating thickness on both sides can be the same or different. At the same time, an explosion-proof groove 120 is provided on the cover plate 110, and the explosion-proof groove 120 includes a first sub-groove 121 and a second sub-groove 122. The first sub-groove 121 and the second sub-groove 122 are both arc-shaped. The first sub-groove 121 and the second sub-groove 122 are located at different positions of the cover plate 110, and the projections of the first sub-groove 121 and the second sub-groove 122 on one side of the cover plate 110 form a closed circle. 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.

[0032] It can be understood that 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 the first sub-groove 121 is opened to discharge combustible materials. Then, the position of the second sub-groove 122 on the cover plate 110 is opened again, and the second sub-groove 122 is opened to discharge combustion-supporting materials. The cover plate 110 at the first sub-groove 121 is opened under the first pressure, and the cover plate 110 at the second sub-groove 122 is opened under the second pressure. The first pressure is less than the second pressure, thereby forming a secondary pressure relief of the battery. The first opening can discharge combustible gas, and the second opening can discharge combustion-supporting gas, thereby achieving the purpose of time-sharing discharge of combustible gas and combustion-supporting gas, overcoming the related When the explosion-proof structure of the technology explodes, the combustible gas, the combustion-supporting gas and the substances in the battery interact with each other, aggravating the degree of thermal runaway and causing the battery to explode. The projections of the first sub-groove 121 and the second sub-groove 122 on one side of the cover plate 110 form a closed circle center, ensuring the pressure relief area. At the same time, 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 between the first sub-groove 121 and the second sub-groove 122, which is conducive 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 the part of the cover plate 110 on the inner side of the first sub-groove 121 and the second sub-groove 122 and the part of the cover plate 110 on the outer side of the first sub-groove 121 and the second sub-groove 122 are completely detached, realizing the complete opening of the explosion-proof structure and ensuring the explosion-proof effect.

[0033] In some embodiments, along the thickness direction of the cover plate 110 , the cross-sectional shape of the explosion-proof groove 120 is V-shaped, trapezoidal, semicircular, U-shaped, or parabolic.

[0034] In some embodiments, referring to FIG. 4 and FIG. 12 , the cover plate 110 includes a first side surface 111 and a second side surface 112 arranged opposite to each other, 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.

[0035] It can be understood that the first sub-groove 121 and the second sub-groove 122 are provided on the first side surface 111 of the cover plate 110 to facilitate the processing of the first sub-groove 121 and the second sub-groove 122 .

[0036] In some embodiments, as shown in FIG7 , the outer diameter of the ring in which the explosion-proof groove 120 is located, as viewed from above the cover plate 110, is E1, and 24 mm ≤ E1 ≤ 40 mm, such as 30 mm ≤ E1 ≤ 35 mm. The value of E1 can be 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, or other unspecified values. The explosion-proof groove 120 is appropriately positioned on the cover plate 110 to create a sufficiently large pressure relief area to ensure effective pressure relief.

[0037] In some embodiments, as shown in FIG5 and FIG6 , 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, where 20 μm ≤ H1 ≤ 115 μm, and 25 μm ≤ H2 ≤ 135 μm. For example, 45 μm ≤ H1 ≤ 55 μm, and 80 μm ≤ H2 ≤ 100 μm. The value of H1 can be 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 115 μm, or other values ​​not specified. The value of H2 can be 25μm, 35μm, 45μm, 55μm, 65μm, 75μm, 85μm, 95μm, 105μm, 115μm, 125μm, 135μm or other unlisted values.

[0038] It is understandable 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 operating 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 to ensure the normal operation of the battery while achieving secondary pressure relief and preventing battery explosion.

[0039] 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 and secondary pressure relief.

[0040] In some embodiments, as shown in FIG5 , the thickness of the area outside the explosion-proof groove 120 on the cover plate 110 is C, where 0.4 mm ≤ C ≤ 1.0 mm. The value of C can be 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, or other unspecified values. Properly setting the thickness of the cover plate 110 ensures the strength of the cover plate 110 while allowing for the formation of the first sub-groove 121 and the second sub-groove 122 to achieve secondary pressure relief.

[0041] In some embodiments, the arc length of the first sub-groove 121 is smaller than the arc length of the second sub-groove 122, wherein the arc length of the first sub-groove 121 refers to the length of the arc of the outer edge of the explosion-proof groove 120 where the first sub-groove 121 is located, and the arc length of the second sub-groove 122 refers to the length of the arc of the outer edge of the explosion-proof groove 120 where the second sub-groove 122 is located.

[0042] In some embodiments, the ratio of the arc length of the first sub-groove 121 to the arc length of the second sub-groove 122 is G. Among them, the value of G can be The arc lengths of the first sub-groove 121 and the second sub-groove 122 are reasonably arranged, and the opening sizes of the primary pressure relief and the secondary pressure relief are reasonably arranged to ensure explosion-proof effect.

[0043] In some embodiments, as shown in FIG6 , the width of the notch of the explosion-proof groove 120 is a, 0.6 mm ≤ a ≤ 1.5 mm. The value of a can be 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, or other unspecified values. The notch width of the explosion-proof groove 120 is appropriately set, and the notch width of the first sub-groove 121 and the second sub-groove 122 are the same. This avoids the notch width of the explosion-proof groove 120 being too small, which is not conducive to processing and opening, and also avoids the notch width of the explosion-proof groove 120 being too large, which would increase the area of ​​the explosion-proof groove 120 and affect the structural strength of the cover plate 110.

[0044] In some embodiments, referring to Figures 9, 11 and 13, 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 alternately arranged, the plurality of first sub-grooves 121 and the plurality of second sub-grooves 122 are located on the same circle, and 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 form a closed circular ring.

[0045] It can be understood that in order to achieve secondary pressure relief, under the first pressure, all the cover plates 110 at the positions of the first sub-grooves 121 are opened, and under the second pressure, all the cover plates 110 at the positions of the second sub-grooves 122 are opened. The first pressure is lower than the second pressure. By arranging multiple first sub-grooves 121 and multiple second sub-grooves 122 on the cover plate 110, it is beneficial for the cover plate 110 at the position of the explosion-proof groove 120 to be fully opened, thereby ensuring the pressure relief area and guaranteeing the pressure relief effect.

[0046] In some embodiments, the cover 110 includes a first sub-portion 113 and a second sub-portion 114, the first sub-portion 113 is adjacent to the second sub-portion 114, the first sub-portion 113 is close to the edge of the cover 110, the surface of the second sub-portion 114 facing the core 140 is at least partially higher than the surface of the first sub-portion 113 facing the core 140, the surface of the second sub-portion 114 away from the core 140 is at least partially higher than the surface of the first sub-portion 113 away from the core 140, and the explosion-proof groove 120 is arranged on the second sub-portion 114.

[0047] It can be understood that the cover plate 110 is designed to have a concave-convex structure. When the cover plate 110 is deformed into a hemispherical or hat-shaped shape, the space between the cover plate 110 and the end of the winding core is increased to prevent the air pressure in the battery from increasing sharply and causing the battery to explode.

[0048] On the basis of the above embodiment, referring to Figures 2, 8 and 13, the cover 110 includes a third sub-portion 115. Along the radial direction of the cover 110, the first sub-portion 113, the second sub-portion 114 and the third sub-portion 115 are concentrically arranged in sequence. The first sub-portion 113 and the second sub-portion 114 are annular, and the third sub-portion 115 is circular. The first sub-portion 113 is close to the edge of the cover 110 and points from the second side 112 to the direction of the first side 111. The surface of the second sub-portion 114 facing the core 140 is at least partially higher than the surface of the first sub-portion 113 facing the core 140. The surface of the second sub-portion 114 away from the core 140 is at least partially higher than the surface of the first sub-portion 113 away from the core 140. The explosion-proof groove 120 is arranged on the second sub-portion 114, and the first sub-groove 121 and the second sub-groove 122 are concentrically arranged with the second sub-portion 114.

[0049] It can be understood that when the air pressure in the battery increases, the cover 110 bulges and deforms in the direction of the first side surface 111, and the heights of the second sub-section 114 and the third sub-section 115 are designed to be higher than the height of the first sub-section 113. After deformation, the cover 110 becomes hemispherical or hat-shaped, which increases the space between the cover 110 and the end of the core 140, preventing the air pressure in the battery from increasing sharply and causing the battery to explode.

[0050] In some embodiments, as shown in Figures 8 and 13, the cover plate 110 also includes a fourth sub-portion 116. The fourth sub-portion 116 is annular and is located between the second sub-portion 114 and the third sub-portion 115. The fourth sub-portion 116 connects the second sub-portion 114 and the third sub-portion 115.

[0051] It can be understood that the explosion-proof groove 120 is set on the second sub-section 114. During the deformation of the cover 110, the deformation force of the first sub-section 113 and the fourth sub-section 116 acts on the explosion-proof groove 120, which is conducive to the smooth opening of the explosion-proof groove 120 and the reliability of the explosion-proof structure.

[0052] In other embodiments, it is also designed that the height of the third sub-section 115 on the first side 111 is higher than the height of the second sub-section 114, the height of the second sub-section 114 is partially higher than the height of the first sub-section 113, and the first sub-section 113 is higher than the fourth sub-section 116; on the second side 112, the fourth sub-section 116 is lower than the first sub-section 113, the first sub-section 113 is lower than the second sub-section 114 at least in part, and the second sub-section 114 is lower than the third sub-section 115.

[0053] It can be understood that when the cover plate 110 is installed on the battery for use, the fourth sub-portion 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 shell 150 is the same, and there is no potential difference, which reduces the risk of corrosion of the cover plate 110 and improves the reliability of the battery pack.

[0054] Based on the above embodiment, the surface of the first sub-section 113 facing the winding core 140 is higher than the surface of the fourth sub-section 116 facing the winding core 140. The fourth sub-section 116 is used to connect to the battery electrodes. When the cover plate 110 is installed on the battery for use, the fourth sub-section 116 of the cover plate 110 is connected to the battery electrodes, and the cover plate 110 is charged. For the battery, the potential between the cover plate 110 and the battery housing 150 is the same, and there is no potential difference. This reduces the risk of corrosion of the cover plate 110 and improves the reliability of the battery pack. In addition, the surface of the first sub-section 113 away from the winding core 140 is higher than the surface of the fourth sub-section 116 away from the winding core 140.

[0055] Based on the above embodiment, the surface of the first sub-section 113 facing the winding core 140, the surface of the fourth sub-section 116 facing the winding core 140, and the surface of the sinking platform 1141 facing the winding core 140 are located at the same height. In addition, the surface of the first sub-section 113 away from the winding core 140, the surface of the fourth sub-section 116 away from the winding core 140, and the surface of the sinking platform 1141 facing the winding core 140 are located at the same height, facilitating the processing and molding of the cover plate 110.

[0056] In some embodiments, referring to FIG. 13 and FIG. 6 , the distance between the first side surface 111 of the second sub-section 114 and the first side surface 111 of the first sub-section 113 is B, 0.8C≤B≤1.5C, where C is the thickness of the area outside the explosion-proof groove 120 on the cover plate 110, such as, B is 0.8C, 0.9C, 1.0C, 1.1C, 1.2C, 1.3C, 1.4C, 1.5C or other unspecified values.

[0057] In some embodiments, the outer diameter of the ring where the explosion-proof groove 120 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 110 is E4, wherein 42mm≤E4≤46mm, such as, E4 is 42mm, 43mm, 44mm, 45mm, 46mm or other unspecified values; 0.75E4≤E3≤0.96E4, 0.4E4≤E2≤0.72E4 and 3C≤E3-E2≤27.8C; E2+C≤E1≤E3-C, C is the thickness of the area outside the explosion-proof groove 120 on the cover 110.

[0058] It is understood that in the embodiment of the present application, the diameter E4 of the cover plate 110 is associated with the corresponding battery product specifications, the dimensions of E2 and E3 are associated with E4, and the dimension of E1 is associated with E2 and E3, thus rationally designing the structural dimensions of the cover plate 110. The structures and parameters of the first sub-section 113, the second sub-section 114, the third sub-section 115, and the fourth sub-section 116 are rationally set to achieve primary and secondary pressure relief of the cover plate 110 while ensuring the strength of the cover plate 110 and the space available after deformation, thereby facilitating the processing of the explosion-proof groove 120.

[0059] In some embodiments, referring to Figures 1, 3, and 8, the second sub-section 114 includes a connected sink 1141 and a boss 1142, the sink 1141 and the boss 1142 forming 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 boss 1142 away from the core 140 is higher than the surface of the sink 1141 away from the core 140. From the second side surface 112 to the direction of the first side surface 111, the sink 1141 and the first sub-section 113 are located at the same height, that is, the first side surface 111 of the sink 1141 and the first side surface 111 of the first sub-section 113 are located in the same horizontal plane, the second side surface 112 of the sink 1141 and the second side surface 112 of the first sub-section 113 are located in the same horizontal plane, the boss 1142 is arranged higher than the sink 1141, the first sub-groove 121 is at least partially arranged on the sink 1141, and the second sub-groove 122 is arranged on the boss 1142.

[0060] It is understood that by forming the sink 1141 and the protrusion 1142 on the second sub-portion 114, the first sub-groove 121 is at least partially disposed on the sink 1141, and the second sub-groove 122 is disposed on the protrusion 1142. When the gas pressure in the battery increases and the cover plate 110 deforms, the first sub-groove 121 at the location of the sink 1141 is subjected to the force of the deformation of the cover plate 110, and the explosion-proof groove 120 is first opened from the sink 1141, thereby achieving directional opening at the location of the first sub-groove 121 and ensuring the orderly conduct of the secondary pressure relief. The explosion-proof groove 120 is first opened from the sink 1141, and there are multiple opening methods, such as the first sub-groove 121 on the sink 1141 being instantly and fully opened, or the first sub-groove 121 having an opening point, and the first sub-groove 121 opening from the opening point until it is fully opened. The opening point may be the intersection of the protrusion 1142 and the sink 1141 on the first sub-groove 121 , or any position on the first sub-groove 121 within the area of ​​the sink 1141 .

[0061] Based on the above embodiment, in the direction from the second side surface 112 to the first side surface 111, the third sub-portion 115 is higher than the boss 1142. That is, the surface of the third sub-portion 115 away from the core 140 is higher than the surface of the boss 1142 away from the core 140, and the surface of the third sub-portion 115 facing the core 140 is higher than the surface of the boss 1142 facing the core 140. This can maximize the space left by the cover plate 110 after deformation.

[0062] In some embodiments, as shown in FIG2 , the depth of the recessed platform 1141 is A, 0.8C≤A≤1.5C, where C is the thickness of the cover plate 110, such as 1C≤A≤1.3C, where A can be 0.8C, 0.9C, 1.0C, 1.1C, 1.2C, 1.3C, 1.4C, 1.5C, or other unspecified values. The depth of the recessed platform 1141 refers to the vertical distance between the first side surface 111 of the protrusion 1142 and the first side surface 111 of the recessed platform 1141.

[0063] In some embodiments, as shown in FIG. 7 , the width of the top of the sink 1141 is D1, and the width of the bottom of the sink 1141 is D2, wherein:

[0064] 4mm≤D1≤12mm;

[0065] D2 = D1 - 2C*tan(α-90°), and D2 > 2 mm;

[0066] α is the angle formed between the bottom and the side of the sink 1141, 100°≤α≤170°;

[0067] C is the thickness of the area outside the explosion-proof groove 120 on the cover plate 110.

[0068] The value of D1 is 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, or other unspecified values, and the value of α is 100°, 110°, 120°, 130°, 140°, 150°, 160°, 170°, or other unspecified values. The dimensions of the sink 1141 are appropriately set to ensure the directional opening effect of the explosion-proof structure.

[0069] In some embodiments, as shown in FIG. 10 , the cover plate 110 includes a first side surface 111 and a second side surface 112 that are oppositely disposed. The first sub-groove 121 and the second sub-groove 122 are both disposed on the second side surface 112 , and the first sub-groove 121 is connected to the second sub-groove 122 .

[0070] It can be understood that arranging the explosion-proof groove 120 on the side of the cover plate 110 close to the winding core is conducive to the explosion-proof groove 120 to ensure the explosion-proof effect.

[0071] In some embodiments, the cover plate 110 includes a first side surface 111 and a second side surface 112 that are oppositely disposed. The first sub-groove 121 is disposed on the first side surface 111 , and the second sub-groove 122 is disposed on the second side surface 112 .

[0072] As a variation, the cover plate 110 includes a first side surface 111 and a second side surface 112 that are oppositely disposed. The second sub-groove 122 is disposed on the first side surface 111 , and the first sub-groove 121 is disposed on the second side surface 112 .

[0073] It is understandable that the first sub-groove 121 and the second sub-groove 122 can be disposed on different sides of the cover plate 110 to facilitate processing.

[0074] In some embodiments, 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 magnitude of the first pressure is P1, 0.5Mpa<P1<1.5Mpa, and the magnitude of the second pressure is P2, 1.5Mpa≤P2<2.5Mpa.

[0075] Under normal operating conditions, the internal pressure of the battery will reach 0.5Mpa. Generally, the internal pressure of the battery will increase with the temperature and electrolyte decomposition for a period of time before the battery triggers thermal runaway. In order to allow the combustible gas decomposed by the electrolyte to be discharged first without affecting the normal operation of the battery, the first pressure P1 is set between 0.5Mpa and 1.5Mpa, such as P1 is set to 0.6Mpa, 0.7Mpa, 0.8Mpa, 0.9Mpa, 1.0Mpa, 1.1Mpa, 1.2Mpa, 1.3Mpa. pa, 1.4 MPa or other unlisted values. At the end of thermal runaway, the pressure inside the battery rises to a certain level and the explosion-proof valve needs to open to release the burning material inside the battery to avoid battery explosion. The second pressure P2 is set between 1.5 MPa and 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.

[0076] In some embodiments, 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 according to the following formulas (1) and (2):

[0077] Wherein, Q is the tensile strength of the material of the cover plate 110;

[0078] E1 is the outer diameter of the ring where the explosion-proof groove 120 is located;

[0079] P1 is the pressure at the first sub-groove 121 at which the cover plate 110 opens;

[0080] P2 is the pressure at which the cover plate 110 at the second sub-groove 122 opens.

[0081] The above formulas (1) and (2) are used to calculate 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. The first sub-groove 121 and the second sub-groove 122 are designed according to different positions and material properties, which facilitates design, ensures accurate calculation results, and ensures the performance of the cover plate 110.

[0082] See Figures 14, 15, 16, 17 and 18. The embodiment of the present application also provides a battery, which can be a cylindrical battery, including the explosion-proof structure described in any of the above embodiments. The explosion-proof structure can be applied to the positive side or the negative side of the battery. The application of the explosion-proof structure to the negative side of the battery is used as an example. The battery includes the above-mentioned explosion-proof structure, a winding core 140 and a shell 150. The winding core 140 is installed in the shell 150. An opening 151 is provided at one end of the shell 150. The cover plate 110 is sealed to the shell 150 to block the opening 151. The battery has the same technical effect as the battery explosion-proof structure and will not be repeated.

[0083] On the basis of the above embodiment, referring to FIG17 and FIG18 , the battery further includes a first current collecting disc 160, a second current collecting disc 170 and an insulating member 180. A positive terminal 152 is provided at the other end of the shell 150. The winding core 140, the first current collecting disc 160 and the second current collecting disc 170 are all disposed in the shell 150. The cover plate 110 is sealed and connected to the shell 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 collecting disc 160. The other side surface of the first current collecting disc 160 is welded to the negative terminal of the winding core 140. The peripheral side of the first current collecting disc 160 is connected to the inner surface of the shell 150 so that the shell 150 is charged. There is no potential difference between the cover plate 110 and the shell 150, which reduces the risk of corrosion of the cover plate 110 and improves the reliability of the battery. The shell 150 A positive terminal 152 is provided at the end facing away from the cover plate 110, and the positive terminal 152 is sealed to the shell 150 by an insulating sealing ring. The second current collecting disc 170 is welded to the positive end of the winding core 140 and the positive terminal 152, and the second current collecting disc 170 is located between the positive end of the winding core 140 and the positive terminal 152. In addition, an insulating member 180 is provided between the second current collecting disc 170 and the end of the shell 150, and the second current collecting disc 170 and the shell 150 are insulated by the insulating member 180.

[0084] In some embodiments, the outer circular area of ​​the explosion-proof groove 120 formed on the cover plate 110 is φ1. It 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. In the direction perpendicular to the axis of the shell 150, the cross-sectional area of ​​the shell 150 is in,

[0085] Understandably, The value of can be 0.27, 0.3, 0.4, 0.5, 0.6, 0.7, 7.6 or other unspecified values. and ratio to ensure the pressure relief effect of the explosion-proof structure.

[0086] In some embodiments, the side wall of the shell 150 near the opening 151 is contracted inward to form a flange 153. A pressure plate 154 is provided on the opening 151 of the shell 150. The pressure plate 154 and the flange 153 are spaced relative to each other. 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 to ensure the sealing of the cover 110. The seal 155 is a sealing ring with a compression rate of 30% to 70%, thereby improving the pressure relief effect of the explosion-proof structure.

[0087] 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.

[0088] The technical solutions and technical effects of the present application are described in detail below through specific examples and comparative examples. The following examples are only some examples of the present application and do not specifically limit the present application.

[0089] This example aims to investigate the effect of applying an explosion-proof structure to a battery on battery performance.

[0090] First test group

[0091] The explosion-proof structure in this test group is as follows: as shown in Figure 12, the cover plate 110 includes a first side surface 111 and a second side surface 112 arranged opposite to each other, 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 is connected to the second sub-groove 122. The parameters of the cover plate 110 involve H1, H2, H2-H1, a, C, G, and E1.

[0092] Test method: Adopt Article 6.2.4 of GB / T31485-2015 standard.

[0093] 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, wherein T1 and T2 meet the following conditions: 50s≤T1≤100s, 60s≤T2≤150s, 5s≤ΔT≤50s.

[0094] Set basic group 1. The parameters and verification results of basic group 1 are shown in Table 1.1 below.

[0095] Table 1.1: Parameters and verification results of basic group 1

[0096] According to the verification results in Table 1.1, the opening time of the first sub-slot 121 and the opening time of the second sub-slot 122 both meet the evaluation standards, meeting the performance of the explosion-proof structure while achieving secondary pressure relief.

[0097] Based on the parameters of basic group 1, the parameter changes of the cover plate 110 are controlled by the single variable method to set the comparative example and the embodiment. The parameter change table and verification results of the comparative example and the embodiment are shown in Tables 1.2 to 1.5.

[0098] Table 1.2: Verification results of comparative examples and examples with basic group 1 as parameters and changes in H1 and H2

[0099] According to Table 1.2, when H1 is within the set range, it meets the performance of the explosion-proof structure and realizes secondary pressure relief. When H1 is not within 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.

[0100] Table 1.3: Verification results of comparative examples and examples with basic group 1 as parameters, achieving H2-H1 change by changing H2

[0101] According to Table 1.3, when H2 and H2-H1 are within the set range, the performance of the explosion-proof structure is met and secondary pressure relief is achieved. When H2-H1 is lower than the set range, the time interval between the two pressure reliefs is short. When H2-H1 is higher than the set range, the time interval between the two pressure reliefs is long, or the second sub-slot 122 is opened late, the effect of the secondary pressure relief of the explosion-proof structure is reduced.

[0102] Table 1.4: Verification results of comparative examples and examples with different G settings using basic group 1 as parameters

[0103] According to Table 1.4, when G is within the set range, it meets the performance of the explosion-proof structure and realizes secondary pressure relief. When G is lower or higher than the set range, the time interval between the two pressure reliefs is shorter or longer, and the secondary pressure relief effect of the explosion-proof structure is reduced.

[0104] Table 1.5: Verification results of comparative examples and examples with basic group 1 as parameters and E1 settings changed

[0105] According to Table 1.5, when E1 is within the set range, the performance of the explosion-proof structure is met and secondary pressure relief is achieved. When E1 is lower or higher than the set range, the time interval between the two pressure reliefs is short and the secondary pressure relief effect of the explosion-proof structure is reduced.

[0106] Second test group

[0107] The explosion-proof structure in this test group is as follows: as shown in Figure 13, the cover plate 110 includes a first side surface 111 and a second side surface 112 arranged opposite to each other, 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. Cover plate 110 includes a first sub-section 113 and a second sub-section 114. First sub-section 113 and second sub-section 114 are adjacent to each other. The first sub-section is located near the edge of cover plate 110 and points from second side 112 toward first side 111. Second sub-section 114 is at least partially higher than first sub-section 113. That is, the surface of second sub-section 114 facing core 140 is at least partially higher than the surface of first sub-section 113 facing core 140. The surface of second sub-section 114 facing away from core 140 is at least partially higher than the surface of first sub-section 113 facing away from core 140. Explosion-proof groove 120 is provided in second sub-section 114. Parameters of cover plate 110 include H1, H2, H2-H1, a, C, G, B, E1, E2, E3, E4, and E3-E2.

[0108] Test method: Adopt Article 6.2.4 of GB / T31485-2015 standard.

[0109] Evaluation criteria: The opening time of the first sub-slot 121 is T1, and the opening time of the second sub-slot 122 is T2, wherein T1 and T2 meet the following conditions: 50s≤T1≤100s, 60≤T2≤150s, 5s≤ΔT≤50s.

[0110] Set basic group 2. The parameters and verification results of basic group 2 are shown in Table 2.1 below.

[0111] Table 2.1: Parameters and verification results of basic group 2

[0112] According to the verification results in Table 2.1, the opening time of the first sub-slot 121 and the opening time of the second sub-slot 122 both meet the evaluation standards, meeting the performance of the explosion-proof structure while achieving secondary pressure relief.

[0113] According to the comparison of the verification results of basic group 1 and basic group 2, it can be seen that setting the explosion-proof groove 120 on the second sub-section 114 will increase the interval difference between the two pressure reliefs while ensuring the safety performance of the battery, thereby improving the secondary pressure relief effect of the explosion-proof structure.

[0114] Based on the parameters of basic group 2, the parameter changes of the cover plate 110 are controlled by the single variable method to set the comparative example and the embodiment. The variable parameters and verification results of the comparative example and the embodiment are shown in Table 2.2 and Table 2.3.

[0115] Table 2.2: Verification results of comparative examples and examples with different B settings using the parameters of basic group 2

[0116] According to Table 2.2, when B is within the set range, the performance of the explosion-proof structure is met and secondary pressure relief is achieved. When B is lower than or exceeds the set range, the time interval between the two pressure reliefs is short and the secondary pressure relief effect of the explosion-proof structure is reduced.

[0117] Table 2.3: Verification results of comparative examples and examples with parameters of basic group 2 and changes in E1, E2, and E3 settings

[0118] According to Table 2.3, E1, E2, E3 and (E3-E2) are all within the set range, meeting the performance of the explosion-proof structure while achieving secondary pressure relief. When E2 is not within the set range, the time interval between the two pressure reliefs is short, and the secondary pressure relief effect of the explosion-proof structure is reduced.

[0119] The third test group

[0120] The explosion-proof structure of this test group is as follows: Referring to FIG1 , the cover plate 110 includes a first side surface 111 and a second side surface 112 disposed opposite each other, a first sub-groove 121 and a second sub-groove 122 both disposed on the first side surface 111, and both the first sub-groove 121 and the second sub-groove 122 are arc-shaped rings, the first sub-groove 121 and the second sub-groove 122 being connected end to end, and the first sub-groove 121 and the second sub-groove 122 being 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 being adjacent, the first sub-portion being close to the edge of the cover plate 110 and pointing from the second side surface 112 to the first side surface 111, the second sub-portion 114 being higher than the first sub-portion 113, and the explosion-proof groove 120 being disposed on the second sub-portion 114. The second sub-section 114 includes a connected sink 1141 and a boss 1142. The sink 1141 and the boss 1142 form a closed ring. From the second side surface 112 to the first side surface 111, the surface of the sink 1141 facing the winding core 140 is at the same height as the surface of the first sub-section 113 facing the winding core 140. The surface of the sink 1141 away from the winding core 140 is at the same height as the surface of the first sub-section 113 away from the winding core 140. It can be understood that the first side surface 111 of the sink 1141 is aligned with the second side surface 111. The first side 111 of a sub-portion 113 lies in the same horizontal plane, the second side 112 of the sink 1141 lies in the same horizontal plane as the second side 112 of the first sub-portion 113, 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, the surface of the boss 1142 away from the winding core 140 is higher than the surface of the sink 1141 away from the winding core 140, the first sub-groove 121 is at least partially disposed on the sink 1141, and the second sub-groove 122 is disposed on the boss 1142. The parameters of the cover plate 110 include H1, H2, H2-H1, a, C, G, A, E1, E2, E3, E4, E3-E2, D1 / D2, and α.

[0121] Test method: Adopt Article 6.2.4 of GB / T31485-2015 standard.

[0122] Evaluation criteria: The opening time of the first sub-slot 121 is T1, and the opening time of the second sub-slot 122 is T2, wherein T1 and T2 meet the following conditions: 50s≤T1≤100s, 60s≤T2≤150s, 15s≤ΔT≤50s.

[0123] Set basic group 3. The parameters and verification results of basic group 3 are shown in Table 3.1 below.

[0124] Table 3.1: Parameters of basic group 3

[0125] According to the verification results in Table 3.1, the opening time of the first sub-slot 121 and the opening time of the second sub-slot 122 both meet the evaluation standards, meeting the performance of the explosion-proof structure while achieving secondary pressure relief.

[0126] According to the comparison of the verification results of basic group 1, basic group 2 and basic group 3, it can be seen that the second sub-section 114 is provided with a sink 1141 and a boss 1142. 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, which is conducive to the secondary pressure relief and further improves the reliability of the explosion-proof structure.

[0127] Based on the parameters of basic group 3, the parameter changes of the cover plate 110 are controlled by the single variable method to set the comparative example and the embodiment. The variable parameters and verification results of the comparative example and the embodiment are shown in Table 3.2.

[0128] Table 3.1: Verification results of comparative examples and examples based on basic group 3, where D1 and D2 are changed as D1 is changed

[0129] According to Table 3.1: When D1 is within the set range, the performance of the explosion-proof structure is met and secondary pressure relief is achieved. When D1 is lower than or exceeds the set range, the time interval between the two pressure reliefs is shorter or longer, and the secondary pressure relief effect of the explosion-proof structure is reduced.

Claims

1. An explosion-proof structure is applied to a battery and includes: A cover plate (110) is provided with an explosion-proof groove (120). The explosion-proof groove (120) includes a first sub-groove (121) and a second sub-groove (122). The projections of the first sub-groove (121) and the second sub-groove (122) on one side of the cover plate (110) form a closed ring. 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).

2. The explosion-proof structure according to claim 1, wherein, 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), and the first sub-groove (121) communicates with the second sub-groove (122).

3. The explosion-proof structure according to claim 1, wherein, The outer diameter of the ring where the explosion-proof groove (120) is located is E1, and 24 mm ≤ E1 ≤ 40 mm.

4. The explosion-proof structure according to any one of claims 1 to 3, wherein, 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, 20 μm ≤ H1 ≤ 115 μm, 25 μm ≤ H2 ≤ 135 μm.

5. The explosion-proof structure according to any one of claims 1 to 3, wherein, 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, and 5 μm ≤ H2 - H1 ≤ 20 μm.

6. The explosion-proof structure according to any one of claims 1 to 3, wherein, The arc length of the first sub-groove (121) is less than the arc length of the second sub-groove (122).

7. The explosion-proof structure according to any one of claims 1 to 3, wherein, The ratio of the arc length of the first sub-groove (121) to the arc length of the second sub-groove (122) is G, 8. The explosion-proof structure according to any one of claims 1 to 3, wherein The thickness of the area outside the explosion-proof groove (120) on the cover plate (110) is C, and 0.4 mm ≤ C ≤ 1.0 mm.

9. The explosion-proof structure according to any one of claims 1 to 3, wherein, The width of the notch of the explosion-proof groove (120) is a, and 0.6 mm ≤ a ≤ 1.5 mm.

10. The explosion-proof structure according to any one of claims 1 to 3, wherein, The explosion-proof groove (120) includes a plurality of the first sub-grooves (121) and a plurality of the second sub-grooves (122), and the first sub-grooves (121) and the second sub-grooves (122) are arranged alternately.

11. The explosion-proof structure according to any one of claims 1 to 3, wherein, 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). In the direction from the second side surface (112) to the first side surface (111), at least part of the second sub-part (114) is arranged higher than the first sub-part (113), and the explosion-proof groove (120) is arranged on the second sub-part (114).

12. The explosion-proof structure according to claim 11, wherein, The second sub - part (114) includes a connected counterbore (1141) and a boss (1142). The counterbore (1141) and the boss (1142) are located on the same circumference. 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 - part (113) facing the core (140). The surface of the boss (1142) away from the core (140) is higher than the surface of the counterbore (1141) away from the core (140) and the surface of the first sub - part (113) away from the core (140). The first sub - groove (121) is at least partially disposed on the counterbore (1141), and the second sub - groove (122) is disposed on the boss (1142).

13. The explosion-proof structure according to claim 12, wherein, The cover plate (110) further includes a third sub - part (115). The third sub - part (115) is circular and is concentrically arranged with the second sub - part (114). The counterbore (1141) and the boss (1142) enclose a closed ring shape.

14. The explosion-proof structure according to claim 13, wherein, 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).

15. The explosion-proof structure according to claim 14, wherein, The surface of the first sub - part (113) facing the core (140) is higher than the surface of the fourth sub - part (116) facing the core (140), and the fourth sub - part (116) is used for connecting with the electrode of the battery; Or, the surface of the first sub - part (113) facing the core (140) is higher than the surface of the fourth sub - part (116) facing the core (140), and the surface of the first sub - part (113) facing the core (140), the surface of the fourth sub - part (116) facing the core (140), and the surface of the counterbore (1141) facing the core (140) are at the same height.

16. The explosion-proof structure according to claim 13, wherein, The height of the surface of the third sub - part (115) facing the core (140) is not lower than the height of the surface of the boss (1142) facing the core (140), and the height of the surface of the third sub - part (115) away from the core (140) is not lower than the height of the surface of the boss (1142) away from the core (140).

17. The explosion-proof structure according to any one of claims 12 to 16, wherein, The depth of the counterbore (1141) is A, and 0.8C ≤ A ≤ 1.5C, where C is the thickness of the area outside the explosion - proof groove (120) on the cover plate (110).

18. The explosion - proof structure according to any one of claims 12 to 16, wherein, The width of the top of the counterbore (1141) is D1, and the width of the bottom of the counterbore (1141) is D2, where 4mm ≤ D1 ≤ 12mm; D2 = D1 - 2C * tan(α - 90°), and D2 > 2mm; α is the included angle formed between the bottom and the side of the sunk platform (1141), where 100° ≤ α ≤ 170°; C is the thickness of the area on the cover plate (110) outside the explosion-proof groove (120).

19. The explosion-proof structure according to any one of claims 12 to 16, wherein, The outer diameter of the ring where the explosion-proof groove (120) is located is E1, the inner diameter of the second sub-part (114) is E2, the outer diameter of the second sub-part (114) is E3, the diameter of the cover plate (110) is E4, and the thickness of the area on the cover plate (110) outside the explosion-proof groove (120) is C. Among them, 42mm ≤ E4 ≤ 46mm; 0.75E4 ≤ E3 ≤ 0.96E4, 0.4E4 ≤ E2 ≤ 0.72E4 and 3C ≤ E3 - E2 ≤ 27.8C; E2 + C ≤ E1 ≤ E3 - C.

20. The explosion-proof structure according to claim 11, wherein, The distance between the first side surface (111) of the second sub-part (114) and the first side surface (111) of the first sub-part (113) is B, where 0.8C ≤ B ≤ 1.5C, and C is the thickness of the area on the cover plate (110) outside the explosion-proof groove (120).

21. The explosion-proof structure according to claim 1, wherein, 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 second side surface (112), and the first sub-groove (121) communicates with the second sub-groove (122); Or, the cover plate (110) includes a first side surface (111) and a second side surface (112) arranged oppositely. 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); Or, the cover plate (110) includes a first side surface (111) and a second side surface (112) arranged oppositely. 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).

22. The explosion-proof structure according to any one of claims 1 to 3, wherein, Calculate 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) according to the following formulas (1) and (2). Among them, Q is the tensile strength of the material for preparing the cover plate (110); E1 is the outer diameter of the ring where the explosion-proof groove (120) is located; P1 is the opening pressure of the cover plate (110) at the first sub-groove (121); P2 is the opening pressure of the cover plate (110) at the second sub-groove (122).

23. The explosion-proof structure according to any one of claims 1 to 3, wherein, 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, semi-circular, trapezoidal, "U"-shaped or parabolic.

24. A battery, comprising: The explosion-proof structure according to any one of claims 1 to 23; The core (140) includes a positive extreme and a negative extreme; The housing (150), the core (140) is installed inside the housing (150), one end of the housing (150) is provided with an opening (151), and the cover plate (110) is hermetically connected to the housing (150) to block the opening (151).

25. The battery according to claim 24 further includes a positive terminal (152), a first current collector plate (160), a second current collector plate (170), and an insulating member (180). The positive terminal (152) is disposed at an end of the housing (150) facing away from the cover plate (110). The first current collector plate (160) is welded to the wound core (140) and disposed between one end of the cover plate (110) and the wound core (140). The second current collector plate (170) is welded to the wound core (140) and the positive terminal (152) and disposed between the wound core (140) and the positive terminal (152). The insulating member (180) is disposed between the second current collector plate (170) and the housing (150).

26. The battery according to claim 24, wherein, The area of the outer circle formed by the explosion-proof groove (120) on the cover plate (110) is In the direction perpendicular to the axis of the housing (150), the cross-sectional area of the housing (150) is 27. The battery according to claim 26, wherein, A flange (153) is formed by inward contraction of a portion of the side wall of the housing (150) near the opening (151). A pressing plate (154) is provided on the opening (151) of the housing (150). The pressing plate (154) is disposed at a relative interval with respect to the flange (153). The cover plate (110) is mounted between the flange (153) and the pressing plate (154).

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