Battery explosion-proof structure, battery and battery pack

Abstract

The utility model provides a battery explosion-proof structure, a battery and a battery pack, the battery explosion-proof structure comprises a cover plate, the cover plate is provided with a first nick and a second nick, the thickness of the cover plate at the first nick is smaller than that of the cover plate at the second nick, the first nick comprises a first section and a second section which are connected, the first section is provided with a first end and a second end, and the second section is provided with a second end. The second section is provided with a third end and a fourth end, and the distance between the first end and the third end is larger than that between the second end and the fourth end. The position of the first nick on the cover plate is firstly opened, and then the position of the second nick is opened, so that secondary pressure relief, combustible gas discharge through first opening and combustion-supporting gas discharge through second opening of the battery are formed, the aim of discharging the combustible gas and the combustion-supporting gas in a time-sharing manner is fulfilled, and the defect that the explosion-proof structure in the related technology cannot discharge the combustible gas and the combustion-supporting gas in a time-sharing manner when the explosion-proof structure is exploded is overcome. The problem of battery explosion caused by intensified thermal runaway degree due to interaction of combustible gas, combustion-supporting gas and substances in the battery is solved, the reliability of the cover plate is improved, and the explosion-proof effect is ensured.

Description

[0001] This application claims priority to the international application filed with the China Patent Office on December 29, 2023, with application number PCT / CN2023 / 143521. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a battery explosion-proof structure, a battery, and a battery pack. Background Art

[0003] The battery cover is typically equipped with an explosion-proof diaphragm, which gradually deforms as internal pressure increases until it explodes. In related technologies, during thermal runaway, when the battery temperature rises to a certain level, the internal electrolyte decomposes into flammable gases such as methane. As the battery temperature continues to rise, combustion-supporting gases such as oxygen are also decomposed inside the battery. When the internal pressure of the battery increases further, the explosion-proof diaphragm explodes. At the moment the explosion-proof diaphragm explodes, the flammable and combustion-supporting gases interact with the substances inside the battery, exacerbating the degree of thermal runaway and easily causing the battery to explode. Utility Model Content

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

[0005] In a first aspect, embodiments of the present application provide a battery explosion-proof structure, comprising a cover plate, wherein a first notch and a second notch are provided on the cover plate, wherein the thickness of the cover plate at the first notch is less than the thickness of the cover plate at the second notch, wherein the first notch includes a first segment and a second segment connected, wherein the first segment has a first end and a second end, and the second segment has a third end and a fourth end, and wherein the distance between the first end and the third end is greater than the distance between the second end and the fourth end.

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

[0007] Roll core;

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

[0009] In a third aspect, an embodiment of the present application provides a battery pack comprising the battery described above.

[0010] The battery explosion-proof structure, battery and battery pack provided in the embodiments of the present application are configured such that a first notch and a second notch are provided on the cover plate, the thickness of the cover plate at the position of the first notch is less than the thickness of the cover plate at the position of the second notch, the first notch includes a first section and a second section connected, the distances between the two ends of the first section and the two ends of the second section are different, which is conducive to the directional opening of the first notch. When the internal pressure of the battery increases, the position of the first notch on the cover plate is opened first, and then the position of the second notch on the cover plate is opened, 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 in the related art that when the explosion-proof structure explodes, the combustible gas, the combustion-supporting gas and the substances in the battery interact to aggravate the degree of thermal runaway and cause the battery to explode, thereby improving the reliability of the cover plate and ensuring the explosion-proof effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] To more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present application. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0012] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings. In the following description, the same reference numerals represent the same parts.

[0013] Figure 1 This is a top view of the first form of the battery explosion-proof structure provided by the embodiments of the present application.

[0014] Figure 2 for Figure 1 Middle AA section view.

[0015] Figure 3 for Figure 1 A partial enlarged view of point A in the middle.

[0016] Figure 4 for Figure 2 A partial enlarged view of point B in the middle.

[0017] Figure 5 A top view of the second form of the battery explosion-proof structure provided in an embodiment of the present application.

[0018] Figure 6 for Figure 5 Middle BB cross-section view.

[0019] Figure 7 This is a labeled diagram of the first notch in the explosion-proof structure of a battery provided in an embodiment of the present application.

[0020] Figure 8 A top view of the third form of the battery explosion-proof structure provided in an embodiment of the present application.

[0021] Figure 9 for Figure 8 Middle LL section view.

[0022] Figure 10 for Figure 8 's labeled diagram.

[0023] Figure 11 A cross-sectional view of a battery provided in an embodiment of the present application.

[0024] Figure 12 for Figure 11 A partial enlarged view of point H in the middle.

[0025] Figure 13 for Figure 11 A partial enlarged view of the M point in the middle.

[0026] Figure 14 A three-dimensional diagram of the battery pack provided in an embodiment of the present application.

[0027] Figure 15 A side view of the battery pack provided in an embodiment of the present application.

[0028] Figure 16 for Figure 15 Middle DD cross-sectional view.

[0029] Description of reference numerals:

[0030] 100, battery; 110, cover; 111, first notch; 1111, first section; 1112, second section; 1113, first end; 1114, second end; 1115, third end; 1116, fourth end; 1117, third section; 1118, second groove wall; 1119, second sub-groove; 112, second notch; 1121, fifth end; 1122, sixth end; 113, first sub-section; 114, second sub-section; 1141, sink; 1142, boss; 115, third sub-section; 116. Fourth sub-section; 117. First side; 118. Second side; 120. Explosion-proof groove; 121. First sub-groove; 1211. First groove wall; 130. Mounting seat; 131. Mounting groove; 132. Baffle; 133. First sub-plate; 134. Second sub-plate; 140. Winding core; 150. Shell; 151. Opening; 152. Positive terminal; 153. Flange; 154. Press plate; 155. Seal; 160. First collecting disc; 170. Second collecting disc; 180. Insulator. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0032] The present invention provides a battery explosion-proof structure, battery, and battery pack to address the problem of battery explosion caused by the interaction between combustible gases, combustion-supporting gases, and materials within the battery when the explosion-proof structure explodes. This will be described below with reference to the accompanying drawings.

[0033] See also Figure 1 、 Figure 5 and Figure 8 A battery explosion-proof structure includes a cover plate 110, which is provided with a first notch 111 and a second notch 112. The thickness of the cover plate 110 at the first notch 111 is less than the thickness of the cover plate 110 at the second notch 112. The first notch 111 includes a first segment 1111 and a second segment 1112 connected to each other. The first segment 1111 has a first end 1113 and a second end 1114. The second segment 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.

[0034] In some embodiments, the cover plate 110 has a disc-shaped structure and can be made of steel, such as SPCC, stainless steels such as SUS410, SUS306, SUS316, SUS430, and SUS444. When SPCC is used, both sides of the cover plate 110 can be nickel-plated with a thickness of 0.3 μm to 8 μm. The thickness of the nickel plating on the two sides can be the same or different.

[0035] It can be understood that since the thickness of the cover plate 110 at the position of the first notch 111 is less than the thickness of the cover plate 110 at the position of the second notch 112, as the air pressure inside the battery increases, the position of the first notch 111 on the cover plate 110 opens first to discharge combustible substances, and then the position of the second notch 112 on the cover plate 110 opens again to discharge combustion-supporting substances. The first notch 111 includes a first section 1111 and a second section 1112 connected together. 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. On one side of the cover plate 110, 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, which is conducive to the opening of the first notch 111.

[0036] In some embodiments, an angle is formed between the first section 1111 and the second section 1112. When the first notch 111 is opened, it is first opened from the second end 1114 and the fourth end 1116, which is conducive to the directional opening of the first notch 111. The cover plate 110 at the first notch 111 opens under the first pressure, and the cover plate 110 at the second notch 112 opens under the second pressure. The first pressure is less than the second pressure. The first pressure and the second pressure both refer to the pressure inside the battery. Thus, a secondary pressure relief of the battery is formed. 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. This overcomes 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 the battery to explode, and has a good explosion-proof effect.

[0037] In some embodiments, see Figure 1 As shown, along the radial direction of the cover plate 110, the first notch 111 and the second notch 112 are spaced apart, and the first notch 111 is closer to the center of the cover plate 110 than the second notch 112. Taking the circular cover plate 110 as an example, the center of the cover plate 110 refers to the position of the center of the circle of the cover plate 110.

[0038] It can be understood that when the air pressure inside the battery increases, the cover 110 deforms and bulges into a hemispherical or hat shape. The first notch 111 is set near the center of the cover 110. The deformation at the position of the first notch 111 is larger, which is conducive to the opening of the first notch 111.

[0039] In some embodiments, see Figure 8 As shown, second score 112 is arc-shaped and has a fifth end 1121 and a sixth end 1122. First score 111 is located between fifth end 1121 and sixth end 1122. In some embodiments, along the circumference of second score 112, the end of first score 111 is spaced apart from the end of second score 112. This provides a sufficiently large pressure relief area to ensure effective pressure relief.

[0040] Based on the above implementation, see Figure 8 As shown, the first notch 111 is connected to the second notch 112 , that is, 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 notch 111 and the second notch 112 form a closed shape.

[0041] It can be understood that the projections of the first notch 111 and the second notch 112 on one side of the cover 110 form a closed shape, which ensures the pressure relief area. When the cover 110 at the position of the first notch 111 is opened, the connection between the first notch 111 and the second notch 112 breaks through the cover 110 at the position of the second notch 112, which is conducive to the opening of the cover 110 at the position of the second notch 112, ensuring that the explosion-proof structure can be opened smoothly, and the part of the cover 110 on the inner side of the first notch 111 and the second notch 112 is completely separated from the part of the cover 110 on the outer side of the first notch 111 and the second notch 112, realizing the complete opening of the explosion-proof structure, and the pressure relief area is large enough to ensure the explosion-proof effect.

[0042] In some embodiments, the second notch 112 is a closed ring, for example, a circular ring or a polygonal ring, and the first notch 111 and the second notch 112 are spaced apart.

[0043] It can be understood that when the cover 110 at the position of the second notch 112 is opened, the cover 110 on both sides of the second notch 112 are completely separated to form a larger pressure relief port, ensuring that the explosion-proof structure can be opened smoothly, achieving full opening of the explosion-proof structure and ensuring the pressure relief effect.

[0044] In some embodiments, see Figure 2 and Figure 3 As shown, the second end 1114 is closer to the center of the cover plate 110 than the first end 1113 , the fourth end 1116 is closer to the center of the cover plate 110 than the third end 1115 , and the first notch 111 protrudes toward the center of the cover plate 110 .

[0045] The distance between the second end 1114 and the center of the cover plate 110 is the same as the distance between the fourth end 1116 and the center of the cover plate 110, and the distance between the first end 1113 and the center of the cover plate 110 is the same as the distance between the third end 1115 and the center of the cover plate 110, that is, the distance between the second end 1114 and the fourth end 1116 and the center of the cover plate 110 is smaller than the distance between the first end 1113 and the third end 1115 and the center of the cover plate 110.

[0046] It can be understood that the first notch 111 is designed to be in an eight-shape, and the tip of the first notch 111 is close to the center of the cover 110. When the cover 110 is deformed by air pressure, the deformation at the second end 1114 and the fourth end 1116 of the first notch 111 is greater than the deformation at the first end 1113 and the third end 1115. The distance between the second end 1114 and the fourth end 1116 is small and the deformation is large, which is conducive to the first notch 111 extending from the second end 1114 and the fourth end 1116 to the first end 1113 and the third end 1115 when it is opened, ensuring that the first notch 111 opens smoothly, which is conducive to one-time pressure relief.

[0047] As a variation, the first end 1113 is closer to the center of the cover plate 110 than the second end 1114 , the third end 1115 is closer to the center of the cover plate 110 than the fourth end 1116 , and the first notch 111 protrudes toward the edge of the cover plate 110 .

[0048] In some embodiments, see Figure 3 As shown, the first notch 111 further includes a third section 1117 , which is disposed between the second end 1114 and the fourth end 1116 . The third section 1117 smoothly transitions between the first section 1111 and the second section 1112 .

[0049] By providing a third section 1117 with a smooth transition between the first section 1111 and the second section 1112, a continuous first notch 111 is formed, and the stress of the cover plate 110 at the third section 1117 is more concentrated. As the air pressure inside the battery increases, the third section 1117 on the cover plate 110 opens first, and then extends to the first section 1111 and the second section 1112 to rupture respectively, which is conducive to the opening of the first notch 111 and ensures a smooth start of pressure relief.

[0050] Based on the above embodiment, the first segment 1111 , the second segment 1112 and the third segment 1117 are all arc-shaped, and the bending direction of the first segment 1111 and the second segment 1112 is different from the bending direction of the third segment 1117 .

[0051] As a variation, the first segment 1111 , the second segment 1112 and the third segment 1117 may also be linear.

[0052] In the embodiment of the present application, the first section 1111, the second section 1112 and the third section 1117 are designed to be 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, ensuring that the first section 1111 and the second section 1112 are smoothly transitioned and connected through the third section 1117, which is conducive to the first notch 111 opening first in the third section 1117, and the arc design can increase the length of the first notch 111 and the opening area, which is conducive to one-time pressure relief.

[0053] In some embodiments, see Figure 5 and Figure 10 As shown, the outer diameter of the second notch 112 is E1, 24mm≤E1≤40mm. For example, 30mm≤E1≤35mm. 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 second notch 112 is appropriately positioned on the cover plate 110 to create a sufficiently large pressure relief area to ensure effective pressure relief.

[0054] In some embodiments, see Figure 7 As shown, the angle β is formed between the chord corresponding to the arc of the first segment 1111 and the chord corresponding to the arc of the second segment 1112, where 30°≤β≤150°. For example, β is 30°, 40°, 50°, 60°, 70°, 80°, 90°, 100°, 110°, 120°, 130°, 140°, 150°, or other unspecified values. The chord corresponding to the arc of the first segment 1111 refers to the straight line on which the chord corresponding to the inner arc of the first segment 1111 lies, and the chord corresponding to the arc of the second segment 1112 refers to the straight line on which the chord corresponding to the inner arc of the second segment 1112 lies. The angle design between the first section 1111 and the second section 1112 is reasonable. Within the range of the angle β, a smooth transition connection is achieved between the first section 1111 and the second section 1112. The better the smoothness of the first section 1111 and the second section 1112, the smoother the opening of the first notch 111, and the avoidance of jamming during the opening process of the first notch 111.

[0055] In some embodiments, see Figure 7 As 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, L1=L2, 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 unlisted values, 4mm≤L1=L2≤8mm, the values ​​of L1 and L2 can be 4mm, 5mm, 6mm, 7mm, 8mm or other unlisted values, the arc lengths of the first section 1111, the second section 1112 and the third section 1117 are reasonably set, when pressure relief is performed, it breaks through from the third section 1117 and extends to both sides, and the first section 1111 and the second section 1112 are symmetrically arranged, so that the two sides are subjected to the same force and the opening speed is the same, thereby ensuring the reliability of one-time pressure relief.

[0056] In some embodiments, see Figure 4As shown, the thickness of the cover plate 110 corresponding to the first notch 111 is H1, and the thickness of the cover plate corresponding to the second notch 112 is H2, wherein 20μm≤H1≤115μm, and 25μm≤H2≤135μm. For example, 45μm≤H1≤55μm, and 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 unspecified values. It can be understood that H1<H2.

[0057] It is understandable that the thicker the cover plate 110 is at the location of the first notch 111 and the second notch 112, the greater the pressure required to open the first notch 111 and the second notch 112. The thickness of the cover plate 110 at the location of the first notch 111 and the second notch 112 is positively correlated with the pressure required to open the first notch 111 and the second notch 112. If the thickness of the cover plate 110 at the location of the first notch 111 and the second notch 112 is thin, the first notch 111 and the second notch 112 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 first notch 111 and the second notch 112 is thick, the pressure required to open the first notch 111 and the second notch 112 is large, making the battery prone to explosion. In the embodiment of the present application, the thickness range of the cover plate 110 where the first notch 111 and the second notch 112 are located is reasonably designed to ensure the normal operation of the battery and achieve secondary pressure relief while preventing the battery from exploding.

[0058] 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.

[0059] In some embodiments, see Figure 4As shown, the thickness of the area outside the first notch 111 and the second notch 112 on the cover plate 110 is C, and 0.4mm≤C≤1.0mm. The value of C can be 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1.0mm, or other unspecified values. Reasonable thickness setting of the cover plate 110 ensures the structural strength of the cover plate 110 while enabling the processing of the first notch 111 and the second notch 112, thereby achieving two-stage pressure relief.

[0060] In some embodiments, see Figure 4 As shown, the notch width of the first notch 111 and the notch width of the second notch 112 are the same, both a, where 0.6mm≤a≤1.5mm. 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 unspecified values. The notch widths of the first notch 111 and the second notch 112 are reasonably set to avoid the notch widths of the first notch 111 and the second notch 112 being too small, which is not conducive to processing and opening, and to avoid the notch widths of the first notch 111 and the second notch 112 being too large, which results in the area of ​​the first notch 111 and the second notch 112 being too large, affecting the structural strength of the cover 110.

[0061] In some embodiments, see Figure 5 As shown, 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 to each other, the first sub-portion 113 is close to the edge of the cover plate 110, at least part of the surface of the second sub-portion 114 facing the core 140 is higher than the surface of the first sub-portion 113 facing the core 140, at least part of the surface of the second sub-portion 114 away from the core 140 is higher than the surface of the first sub-portion 113 away from the core 140, and the first notch 111 and the second notch 112 are both arranged on the second sub-portion 114.

[0062] Understandably, see Figure 6As shown, the cover plate 110 includes a first side 117 and a second side 118. The first side 117 is the side of the cover plate 110 away from the core 140, and the second side 118 is the side of the cover plate 110 facing the core 140. Along the direction of the second side 118 pointing to the first side 117, the second sub-portion 114 is at least partially higher than the first sub-portion 113, that is, the first side 117 of the second sub-portion 114 is at least higher than the first side 117 of the first sub-portion 113, and the second side 118 of the second sub-portion 114 is at least higher than the second side 118 of the first sub-portion 113. The cover plate 110 is designed to have a concave-convex structure. When the pressure inside the battery increases, the cover plate 110 is deformed into a hemispherical or hat-shaped shape, which increases the space between the cover plate 110 and the end of the core to prevent the air pressure in the battery from increasing sharply, resulting in a battery explosion.

[0063] Based on the above implementation, see Figure 5 As shown, the cover plate 110 also includes a third sub-portion 115. The first sub-portion 113, the second sub-portion 114 and the third sub-portion 115 are integrally formed by a stamping process. Along the radial direction of the cover plate 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 plate 110 and points from the second side surface 118 to the first side surface 117, that is, away from the battery. The second sub-portion 114 is at least partially higher than the first sub-portion 113, and the third sub-portion 115 is higher than the first sub-portion 113. The first notch 111 and the second notch 112 are concentrically arranged with the second sub-portion 114.

[0064] It can be understood that when the air pressure in the battery increases, the cover 110 bulges and deforms, 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, preventing the air pressure in the battery from increasing sharply and causing the battery to explode.

[0065] In some embodiments, see Figure 5 As shown, the cover plate 110 further includes a fourth sub-portion 116 . The fourth sub-portion 116 is annular and 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 .

[0066] The cover plate 110 is configured to have a structure in which the first sub-section 113 , the second sub-section 114 , the fourth sub-section 116 and the third sub-section 115 are sequentially connected, which can be formed by stamping, thereby facilitating the processing and forming of the cover plate 110 .

[0067] Based on the above embodiment, the surface of the first sub-portion 113 facing the core 140 is higher than the surface of the fourth sub-portion 116 facing the core 140, and the surface of the first sub-portion 113 away from the core 140 is higher than the surface of the fourth sub-portion 116 away from the core 140. The fourth sub-portion 116 is used to connect the electrodes of the battery.

[0068] It can be understood that the first notch 111 and the second notch 112 are arranged 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 first notch 111 and the second notch 112, which is conducive to the smooth opening of the first notch 111 and the second notch 112. The fourth sub-section 116 is connected to the electrode of the battery, the cover 110 is charged, and the electric potential between the cover 110 and the shell 150 is the same, and there is no potential difference, which reduces the risk of corrosion of the cover 110 and improves the reliability of the battery.

[0069] In some embodiments, see Figure 6 As shown, the distance between the first side surface 117 of the second sub-section 114 and the first side surface 117 of the first sub-section 113 along the thickness direction of the cover plate 110 is B, 0.8C≤B≤1.5C, wherein C is the thickness of the area outside the first notch 111 and the second notch 112 on the cover plate 110, such as, B takes the value of 0.8C, 0.9C, 1.0C, 1.1C, 1.2C, 1.3C, 1.4C, 1.5C or other unlisted values.

[0070] In some embodiments, see Figure 8 As shown, 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, away from the direction of the winding core 140. The sink 1141 and the first sub-section 113 are located at the same height, the first side surface 117 of the sink 1141 and the first side surface 117 of the first sub-section 113 are located in the same horizontal plane, the second side surface 118 of the sink 1141 and the second side surface 118 of the first sub-section 113 are located in the same horizontal plane, the boss 1142 is higher than the sink 1141 and the first sub-section 113, the first notch 111 is at least partially provided on the sink 1141, and the second notch 112 is provided on the boss 1142.

[0071] It is understandable that by forming a recessed platform 1141 and a protruding platform 1142 on the second sub-section 114, the first notch 111 is set on the recessed platform 1141, and the second notch 112 is set on the protruding platform 1142. When the air pressure in the battery increases and the cover plate 110 deforms, the first notch 111 at the position of the recessed platform 1141 is subjected to the force of the deformation of the cover plate 110, thereby achieving directional opening at the position of the first notch 111, ensuring the orderly conduct of the secondary pressure relief. The directional opening method of the first notch 111 includes the following two situations: the first notch 111 is fully opened instantly; or the first notch 111 has an opening point, and the first notch 111 opens from the opening point until the first notch 111 is fully opened. The opening point is the intersection of the boss 1142 and the sink 1141 on the first notch 111, or the opening point is any position on the third section 1117 of the first notch 111, or the opening point is any position of the first section 1111 and the second section 1112 of the first notch 111 within the sink 1141 area.

[0072] As a variation, the surface of the first sub-section 113 facing the winding core 140, the surface of the sinking platform 1141 facing the winding core 140, and the surface of the fourth sub-section 116 facing the winding core 140 are located at the same height. Furthermore, the surface of the first sub-section 113 away from the winding core 140, the surface of the sinking platform 1141 away from the winding core 140, and the surface of the fourth sub-section 116 away from the winding core 140 are located at the same height, facilitating the processing and molding of the cover plate 110.

[0073] In some embodiments, the surface of the third sub-portion 115 facing the winding core 140, the surface of the boss 1142 facing the winding core 140, and the surface of the fourth sub-portion 116 facing the winding core 140 are located at the same height. Furthermore, the surface of the third sub-portion 115 away from the winding core 140, the surface of the boss 1142 away from the winding core 140, and the surface of the fourth sub-portion 116 facing the winding core 140 are also located at the same height, facilitating the processing and molding of the cover plate 110.

[0074] In some embodiments, see Figure 9 As shown, the depth of the recessed platform 1141 is A, 0.8C≤A≤1.5C, where C is the thickness of the area outside the first notch 111 and the second notch 112 on 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 A of the recessed platform 1141 refers to the vertical distance between the first side surface 117 of the protrusion 1142 and the first side surface 117 of the recessed platform 1141.

[0075] In some embodiments, see Figure 10As shown, the width of the top of the sink 1141 is D1, and the width of the bottom of the sink 1141 is D2, wherein 4mm≤D1≤12mm;

[0076] D2 = D1 - 2C*tan(α-90°), and D2 > 2 mm;

[0077] α is the angle formed between the bottom and the side of the sink 1141, 100°≤α≤170°;

[0078] C is the thickness of the area outside the first notch 111 and the second notch 112 on the cover plate 110 .

[0079] The value of D1 is 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 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 battery explosion-proof structure.

[0080] In some embodiments, under a first pressure, the cover plate 110 at the first notch 111 opens, and under a second pressure, the cover plate 110 at the second notch 112 opens. The magnitude of the first pressure is P1, 0.5 MPa<P1<1.5 MPa, and the magnitude of the second pressure is P2, 1.5 MPa≤P2<2.5 MPa.

[0081] 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 without affecting the normal operation of the battery, the first pressure P1 is set to (0.5Mpa, 1.5Mpa), such as P1 is set to 0.6Mpa, 0.7Mpa, 0.8Mpa, 0.9Mpa, 1.0Mpa, 1.1Mpa, 1.2Mpa, 1.3Mpa, 1 .4Mpa or other unlisted values. At the end of battery thermal runaway, the battery pressure rises to a certain level and the explosion-proof valve needs to open and release the burning material inside the battery to avoid battery explosion. The second pressure is set in [1.5Mpa, 2.5Mpa), such as P2 is set to 1.5Mpa, 1.6Mpa, 1.7Mpa, 1.8Mpa, 1.9Mpa, 2.0Mpa, 2.1Mpa, 2.2Mpa, 2.3Mpa, 2.4Mpa or other unlisted values.

[0082] In some embodiments, the cross-sectional shape of the first notch 111 and / or the second notch 112 along the thickness direction of the cover plate 110 is V-shaped, semicircular, trapezoidal, U-shaped, or parabolic. The cross-sectional shapes of the first notch 111 and the second notch 112 on the cover plate 110 can be the same or different, and the diversity of the cross-sectional shapes facilitates processing.

[0083] In some embodiments, the thickness H2 of the cover plate 110 at the second notch 112 is calculated according to the following formula (1):

[0084]

[0085] Wherein, Q is the tensile strength of the material of which the cover plate 110 is made;

[0086] E1 is the outer diameter of the ring where the second notch is located;

[0087] P2 is the pressure at the second notch 112 for opening the cover plate 110 .

[0088] The thickness H2 of the cover plate 110 at the second notch 112 is calculated using the above formula (1). The second notch 112 is designed according to different positions and material properties, and the thickness H1 of the cover plate 110 at the first notch 111 is designed based on the second notch 112. This facilitates design, provides accurate calculation results, and ensures the performance of the cover plate 110.

[0089] In some embodiments, see Figure 6 As shown, the cover plate 110 includes a first side surface 117 and a second side surface 118 that are oppositely disposed, and the first notch 111 and the second notch 112 are both disposed on the first side surface 117;

[0090] Alternatively, the cover plate 110 includes a first side surface 117 and a second side surface 118 that are oppositely disposed, and the first notch 111 and the second notch 112 are both disposed on the second side surface 118;

[0091] Alternatively, the cover plate 110 includes a first side surface 117 and a second side surface 118 disposed opposite to each other, the first notch 111 is disposed on the first side surface 117 , and the second notch 112 is disposed on the second side surface 118 ;

[0092] Alternatively, the cover plate 110 includes a first side surface 117 and a second side surface 118 that are oppositely disposed, the first notch 111 is disposed on the second side surface 118 , and the second notch 112 is disposed on the first side surface 117 .

[0093] It is understandable that the first notch 111 and the second notch 112 are positioned in various positions on the cover plate 110 so as to achieve the purpose of primary pressure relief and secondary pressure relief. The diverse design facilitates the processing and forming of the first notch 111 and the second notch 112.

[0094] See also Figure 11 、 Figure 12 and Figure 13 As shown, an embodiment of the present application further provides a battery, comprising the above-mentioned battery explosion-proof structure, a winding core 140, and a housing 150. The winding core 140 is installed in the housing 150. An opening 151 is defined at one end of the housing 150. The cover 110 is sealed to the housing 150 to block the opening 151. The battery explosion-proof structure in this embodiment has the same functions and effects as the battery explosion-proof structure in any of the above-mentioned embodiments, and will not be further described here.

[0095] Based on the above implementation, see Figure 12 and Figure 13 As shown, the battery further includes a first current collecting disc 160, a second current collecting disc 170 and an insulating member 180. 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 118 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 edge of the first current collecting disc 160 is connected to the inner surface of the shell 150 so that the cover plate 110 and the shell 150 are 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 battery. Reliability, a positive terminal 152 is provided at one end of the shell 150 away from the cover plate 110, and the positive terminal 152 is sealed to the shell 150 by an insulating sealing ring. The second collecting disc 170 is welded to the winding core 140 and the positive terminal 152 and is provided 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 collecting disc 170 and the end of the shell 150, and the second collecting disc 170 and the shell 150 are insulated by the insulating member 180.

[0096] In some embodiments, see Figure 12 As shown, the cover plate 110 and the shell 150 are sealed by a seal 155, which facilitates the assembly of the cover plate 110 and the shell 150 and has a simple process. The edge of the first collecting disk 160 is connected to the inner wall of the shell 150 so that the shell 150 is negatively charged. The first collecting disk 160 and the cover plate 110 may be in contact or not. When the first collecting disk 160 is in contact with the cover plate 110, the cover plate 110 is also negatively 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.

[0097] Based on the above implementation, see Figure 12As shown, the sidewall of the housing 150 near the opening 151 is contracted inward to form a flange 153. The sidewall of the opening 151 of the housing 150 is curled to form a pressure plate 154. The pressure plate 154 is spaced apart from the flange 153. The cover 110 is installed between the flange 153 and the pressure plate 154. A seal 155 is provided between the cover 110, the flange 153, and the pressure plate 154 to ensure the sealing of the battery. Specifically, the seal 155 is a sealing ring with a compression rate of 30% to 70% to improve the sealing effect.

[0098] 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 performance. At this time, the first collecting plate 160 is in direct contact with the shell 150 to make the shell 150 negatively charged.

[0099] The present application also provides a battery pack including the above-mentioned battery 100. The battery pack has the same technical effects as the battery explosion-proof structure, and will not be described in detail.

[0100] In some embodiments, see Figure 14 、 Figure 15 and Figure 16 As shown, the battery pack also includes a mounting base 130, which is provided with a plurality of mounting grooves 131 and a plurality of baffles 132. The batteries, the mounting grooves 131 and the baffles 132 correspond one to one. The end of the battery 100 close to the cover 110 is installed in the mounting groove 131, and the baffle 132 is located on the side of the mounting groove 131 away from the battery 100. The first notch 111 has a first groove wall 1118 and a second groove wall 1119. The second groove wall 1119 is closer to the center of the cover 110 than the first groove wall 1118. The projection of the baffle 132 on one side of the cover 110 is located on the side of the first groove wall 1118 away from the second groove wall 1119.

[0101] In some embodiments, the width of the baffle 132 is greater than or equal to the length of the first notch 111. The baffle 132 may be a flat plate or a curved plate.

[0102] It can be understood that as the pressure inside the battery 100 increases, the first notch 111 in the sink 1141 opens, and the gas and substances in the battery 100 are ejected from the side of the first notch 111. 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 110 is located is aligned with the first notch 111. 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.

[0103] See also Figure 16It can be seen that the baffle 132 is an arc-shaped plate, and the width d1 of the baffle 132 is greater than the width d2 of the area where the first notch 111 is located, so that the baffle 132 has a larger blocking area and a better blocking effect.

[0104] Based on the above implementation, see Figure 15 As shown, the mounting base 130 includes a first sub-plate 133 and a second sub-plate 134. The first sub-plate 133 and the second sub-plate 134 are spaced apart from each other and connected to each other. A mounting groove 131 is defined on the first sub-plate 133, and a baffle 132 is located between the first sub-plate 133 and the second sub-plate 134 and connected to the first sub-plate 133. When the cover 110 is opened, the material flowing out flows between the first sub-plate 133 and the second sub-plate 134 to avoid affecting other batteries.

[0105] 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.

[0106] First test group

[0107] The structure of the battery explosion-proof structure in this test group is: Figure 1 As shown, a first notch 111 and a second notch 112 are provided on the first side surface 117 of the cover plate 110. The first notch 111 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 notch 112 is annular. Along the radial direction of the cover plate 110, the first notch 111 is closer to the center of the cover plate 110 than the second notch 112.

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

[0109] Evaluation criteria: The opening time of the first notch 111 is T1, the opening time of the second notch 112 is T2, and the opening time difference between the first notch 111 and the second notch 112 is ΔT, wherein T1 and T2 meet the following conditions: 50s≤T1≤100s, 60s≤T2≤150s, and time 5s≤ΔT≤50s.

[0110] The parameters involved in the cover plate 110 include: H1, H2, H2-H1, a, C, E1, L1, L2, L3, β, L1 and L2 are the same, and the parameters of the basic group 1 are shown in the following Table 1.1.

[0111] Table 11: Parameters and verification results of basic group 1

[0112]

[0113] According to the verification results in Table 1.1, the opening time of the first notch 111 and the opening time of the second notch 112 both meet the evaluation criteria, meeting the performance of the explosion-proof structure while achieving secondary pressure relief.

[0114] 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 1.8.

[0115] Table 1.2: Verification results of comparative examples and examples based on basic group 1, with changes in H1 and H2

[0116] H1 / μm H2 / μm Verify the results Example 1 20.0 25.0 T1=50s, T2=60s, ΔT=10s Example 2 67.0 72.0 T1=76s, T2=87s, ΔT=11s Comparative Example 1 15.0 20.0 T1=43s, T2=48s, ΔT=5s Comparative Example 2 120.0 125.0 T1=126s, T2=130s, ΔT=4s

[0117] 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 lower than the set range, the opening time of the first and 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 pressure relief effect of the explosion-proof structure is not good.

[0118] Table 1.3: Verification results of comparative examples and examples using basic group 1 as parameters and changing H2 to achieve the change of H2-H1

[0119]

[0120]

[0121] According to Table 1.3, when H2-H1 is within the set range, the performance of the explosion-proof structure is met while achieving secondary pressure relief. When H2-H1 is lower than the set range, the time interval between the two pressure reliefs is short. When H2-H1 exceeds the set range, the time interval between the two pressure reliefs is long, resulting in an increased probability of battery explosion and a reduced secondary pressure relief effect of the explosion-proof structure.

[0122] Table 1.4: Verification results of comparative examples and examples with different L3 settings using basic group 1 as parameters

[0123] L3 / mm Verify the results Example 1 1.0 T1=90s, T2=123s, ΔT=33s Example 2 3.0 T1=86s, T2=126s, ΔT=40s Comparative Example 1 0.5 T1=119s, T2=123s, ΔT=4s Comparative Example 2 4.0 T1=70s, T2=125s, ΔT=55s

[0124] According to Table 1.4, when L3 is within the set range, it meets the performance of the explosion-proof structure and realizes secondary pressure relief. When L3 exceeds the set range, the time interval between the two pressure reliefs is longer. When L3 is lower than 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 reduced.

[0125] Table 1.5: Verification results of comparative examples and examples with basic group 1 as parameters and changing the settings of L1 and L2

[0126] L1 and L2 / mm Verify the results Example 1 4.0 T1=93s, T2=124s, ΔT=31s Example 2 8.0 T1=97s, T2=126s, ΔT=29s Comparative Example 1 1.0 T1=84s, T2=136s, ΔT=52s Comparative Example 2 15.0 T1=100s, T2=104s, ΔT=4s

[0127] According to Table 1.5, when L1 and L2 are within the set range, they meet the performance of the explosion-proof structure and achieve secondary pressure relief. When L1 and L2 are lower than the set range, the time interval between the two pressure reliefs is longer. When L1 and L2 exceed 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 reduced.

[0128] Table 1.6: Verification results of comparative examples and examples with different β settings using basic group 1 as parameters

[0129] β Verify the 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

[0130] According to Table 1.6, when β is within the set range, the performance of the explosion-proof structure is met while achieving secondary pressure relief. When β is lower than the set range, the time interval between the two pressure reliefs is shorter. When β exceeds 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.

[0131] Second test group

[0132] The explosion-proof structure of the battery in this test group is: Figure 5 As shown, a first notch 111 and a second notch 112 are provided on a first side surface 117 of the cover plate 110. The first notch 111 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 notch 112 is annular. Along the radial direction of the cover plate 110, the first notch 111 is closer to the center of the cover plate 110 than the second notch 112. The cover plate 110 includes a first subsection 113 and a second subsection 114. The first notch 111 and the second notch 112 are both provided on the second subsection 114.

[0133] Test method: Adopt Article 6.2.4 of GB / T31485-2015 standard.

[0134] Evaluation criteria: The opening time of the first notch 111 is T1, the opening time of the second notch 112 is T2, and the time interval between the opening of the first notch 111 and the second notch 112 is ΔT, wherein T1 and T2 meet the following conditions: 50s≤T1≤100s, 60s≤T2≤150s, 5s≤ΔT≤50s.

[0135] The parameters involved in the cover plate 110 include: H1, H2, H2-H1, a, C, L1, L2, L3, β, B, and E1. Set basic group 2. The parameters and verification results of basic group 2 are shown in Table 2.1.

[0136] Table 2.1: Parameters and verification results of basic group 2

[0137]

[0138] According to the verification results in Table 2.1, the opening time of the first notch 111 and the opening time of the second notch 112 both meet the evaluation criteria, meeting the performance of the explosion-proof structure while achieving secondary pressure relief.

[0139] 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.

[0140] Table 2.2: Verification results of comparative examples and examples with different B settings using the parameters of basic group 2

[0141] B / mm Verify the 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

[0142] According to Table 2.2, 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 reliefs is shorter. When B exceeds the set range, the time interval between the two pressure reliefs is longer, and the effect of the secondary pressure relief of the explosion-proof structure is reduced.

[0143] The third test group

[0144] The explosion-proof structure of the battery in this test group is: Figure 8As shown, cover plate 110 includes a first side surface 117 and a second side surface 118 disposed opposite each other. A first notch 111 and a second notch 112 are both disposed on first side surface 117. The projections of first notch 111 and second notch 112 on one side surface of cover plate 110 form a closed shape, i.e., first notch 111 and second notch 112 are connected end to end, and first notch 111 and second notch 112 are in communication. Cover plate 110 includes a first sub-portion 113 and a second sub-portion 114. First sub-portion 113 and second sub-portion 114 are adjacent to each other. The first sub-portion is close to the edge of cover plate 110 and points from second side surface 118 toward first side surface 117. Second sub-portion 114 is at least partially higher than first sub-portion 113. First notch 111 and second notch 112 are disposed on second sub-portion 114. The second sub-section 114 is provided with a connected sink 1141 and a boss 1142, and the sink 1141 and the boss 1142 form a closed ring. The first side surface 117 of the sink 1141 and the first side surface 117 of the first sub-section 113 are located in the same horizontal plane, and the second side surface 118 of the sink 1141 and the second side surface 118 of the first sub-section 113 are located in the same horizontal plane. The surface of the boss 1142 facing the core 140 is higher than the surface of the first sub-section 113 facing the core 140 and the surface of the sink 1141 facing the core 140. The surface of the boss 1142 away from the core 140 is higher than the surface of the first sub-section 113 away from the core 140 and the surface of the sink 1141 away from the core 140. The first notch 111 is at least partially provided on the sink 1141, and the second notch 112 is provided on the boss 1142.

[0145] Test method: Adopt Article 6.2.4 of GB / T31485-2015 standard.

[0146] Evaluation criteria: The opening time of the first notch 111 is T1, the opening time of the second notch 112 is T2, and the time interval between the opening of the first notch 111 and the second notch 112 is ΔT, wherein T1 and T2 meet the following conditions: 50s≤T1≤100s, 60s≤T2≤150s, 5s≤ΔT≤50s.

[0147] The parameters of the cover plate 110 involve H1, H2, H2-H1, a, C, E1, L1, L2, L3, β, A, D1, D2 and α.

[0148] Set basic group 3. The parameters and verification results of basic group 3 are shown in 3.1 below.

[0149] Table 3.1: Parameters and verification results of basic group 3

[0150]

[0151] According to the verification results in Table 3.1, the opening time of the first notch 111 and the opening time of the second notch 112 both meet the evaluation criteria, meeting the performance of the explosion-proof structure while achieving secondary pressure relief.

[0152] 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.

[0153] Table 3.2: Verification results of comparative examples and examples based on basic group 3, where D1 is changed and D2 is set according to the change of D1

[0154] D1 / mm D2 / mm Verify the results Example 1 4.00 3.20 T1=85s, T2=120s, ΔT=35s Example 2 12.00 11.20 T1=86s, T2=110s, ΔT=24s 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

[0155] According to Table 3.2: When D1 is within the set range, the purpose of secondary pressure relief can be achieved. When D1 is lower than the set range, the time interval between the two pressure reliefs is longer. When D1 exceeds the set range, the time interval between the two pressure reliefs is shorter, and the effect of the secondary pressure relief of the explosion-proof structure is reduced.

[0156] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0157] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more features.

[0158] The above describes in detail the explosion-proof structure and battery provided in the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only intended to help understand the method and core concept of the present application. At the same time, those skilled in the art may vary the specific implementation methods and application scopes based on the concepts of the present application. In summary, the contents of this specification should not be construed as limiting the present application.

Claims

1. A battery explosion-proof structure, characterized in that: The invention comprises a cover plate (110), wherein the cover plate (110) is provided with a first notch (111) and a second notch (112), wherein the thickness of the cover plate (110) at the first notch (111) is smaller than the thickness of the cover plate (110) at the second notch (112), wherein the first notch (111) comprises a first segment (1111) and a second segment (1112) connected to each other, wherein the first segment (1111) has a first end (1113) and a second end (1114), wherein the second segment (1112) has a third end (1115) and a fourth end (1116), and wherein 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); The first section (1111) and the second section (1112) form an angle so that the first notch (111) opens at the second end (1114) and / or the fourth end (1116).

2. The battery explosion-proof structure according to claim 1, characterized in that: The first notch (111) and the second notch (112) are spaced apart, and the first notch (111) is closer to the center of the cover plate (110) than the second notch (112).

3. The battery explosion-proof structure according to claim 1, characterized in that: The second notch (112) is arc-shaped, and the second notch (112) has a fifth end (1121) and a sixth end (1122), and the first notch (111) is located between the fifth end (1121) and the sixth end (1122).

4. The battery explosion-proof structure according to claim 3, 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 notch (111) and the second notch (112) are connected to form a closed shape.

5. The battery explosion-proof structure according to claim 1, 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).

6. The battery explosion-proof structure according to claim 1, characterized in that: The first notch (111) further includes a third section (1117), which is disposed 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).

7. The battery explosion-proof structure according to claim 6, 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.

8. The battery explosion-proof structure according to claim 7, 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°.

9. The battery explosion-proof structure according to claim 7, 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.

10. The battery explosion-proof structure according to claim 1, characterized in that: The second notch (112) is annular.

11. The battery explosion-proof structure according to claim 10, characterized in that: The outer diameter of the second notch (112) is E1, 24 mm ≤ E1 ≤ 40 mm.

12. The battery explosion-proof structure according to claim 10, characterized in that: The thickness H2 of the cover plate (110) at the second notch (112) is calculated according to the following formula (1): Wherein, Q is the tensile strength of the material of which the cover plate (110) is made; E1 is the outer diameter of the ring where the second notch is located; P2 is the pressure at which the cover plate (110) is opened at the second notch (112).

13. The battery explosion-proof structure according to claim 1, characterized in that: The thickness of the cover plate corresponding to the first notch (111) is H1, and the thickness of the cover plate corresponding to the second notch (112) is H2, wherein 20 μm≤H1≤115 μm, and 25 μm≤H2≤135 μm.

14. The battery explosion-proof structure according to claim 13, characterized in that: 5μm≤H2-H1≤20μm.

15. The battery explosion-proof structure according to any one of claims 1 to 14, characterized in that: The notch width of the first notch (111) and the notch width of the second notch (112) are both the same as a, wherein 0.6 mm ≤ a ≤ 1.5 mm.

16. The battery explosion-proof structure according to any one of claims 1 to 14, characterized in that: The thickness of the area outside the first notch (111) and the second notch (112) on the cover plate (110) is C, and 0.4 mm ≤ C ≤ 1.0 mm.

17. The battery explosion-proof structure according to any one of claims 1 to 14, characterized in that: The cover plate (110) includes a first sub-portion (113) and a second sub-portion (114), wherein 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 the 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 the surface of the first sub-portion (113) away from the winding core (140), and the first notch (111) and the second notch (112) are both arranged on the second sub-portion (114).

18. The battery explosion-proof structure according to claim 17, characterized in that: The second sub-section (114) includes a boss (1142) and a sink (1141), the surface of the boss (1142) facing the core (140) is higher than the surface of the first sub-section (113) facing the core (140) and the surface of the sink (1141) facing the core (140), the surface of the boss (1142) away from the core (140) is higher than the surface of the first sub-section (113) away from the core (140) and the surface of the sink (1141) away from the core (140), and the first notch (111) is at least partially arranged on the sink (1141).

19. The battery explosion-proof structure according to claim 18, characterized in that: The cover plate (110) further includes a third sub-section (115), the second sub-section (114) is located between the first sub-section (113) and the third sub-section (115), the third sub-section (115) is circular, the third sub-section (115) and the second sub-section (114) are concentrically arranged, and the sink (1141) and the boss (1142) form a closed ring.

20. The battery explosion-proof structure according to claim 19, characterized in that: The cover plate (110) further includes a fourth sub-portion (116), which is annular and 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).

21. The battery 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 the electrodes of the battery; Alternatively, the surface of the first sub-portion (113) facing the winding core (140), the surface of the sinking platform (1141) facing the winding core (140), and the surface of the fourth sub-portion (116) facing the winding core (140) are located at the same height; And / or, the surface of the third sub-portion (115) facing the winding core (140) is at the same height as 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 at the same height as the surface of the boss (1142) away from the winding core (140).

22. The battery explosion-proof structure according to claim 18, 19, 20 or 21, 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 first notch (111) and the second notch (112) on the cover plate (110).

23. The battery explosion-proof structure according to claim 18, 19, 20 or 21, 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 > 2 mm; 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 first notch (111) and the second notch (112) on the cover plate (110).

24. The battery explosion-proof structure according to any one of claims 1 to 14, characterized in that: Along the thickness direction of the cover plate (110), the cross-sectional shape of the first notch (111) and / or the second notch (112) is V-shaped, semicircular, trapezoidal, U-shaped or parabolic.

25. The battery explosion-proof structure according to any one of claims 1 to 14, characterized in that: The cover plate (110) comprises a first side surface (117) and a second side surface (118) that are arranged opposite to each other, and the first notch and the second notch are both arranged on the first side surface (117); Alternatively, the cover plate (110) includes a first side surface (117) and a second side surface (118) that are arranged opposite to each other, and the first notch and the second notch are both arranged on the second side surface (118); Alternatively, the cover plate (110) includes a first side surface (117) and a second side surface (118) that are arranged opposite to each other, the first notch is arranged on the first side surface (117), and the second notch is arranged on the second side surface (118); Alternatively, the cover plate (110) includes a first side surface (117) and a second side surface (118) that are arranged opposite to each other, the first notch is arranged on the second side surface (118), and the second notch is arranged on the first side surface (117).

26. A battery, characterized in that: include: The battery explosion-proof structure according to any one of claims 1 to 25; Roll core (140); The shell (150) is provided with the winding core (140) and an opening (151) is provided at one end of the shell (150). The cover plate (110) is sealedly connected to the shell (150) to block the opening (151).

27. The battery according to claim 26, characterized in that The battery further comprises: a positive terminal (152), a first current collecting disc (160), a second current collecting disc (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 disc (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 edge of the first current collecting disc (160) is connected to the shell (150); the second current collecting disc (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 disc (170) and the shell (150).

28. The battery according to claim 26, characterized in that The cover plate (110) and the housing (150) are laser welded; Alternatively, the cover plate (110) and the housing (150) are sealed and connected via a sealing member (155).

29. A battery pack, characterized in that: Comprising a battery as claimed in any one of claims 26 to 28.

30. The battery pack according to claim 29, wherein: 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) facing away from the battery; the first notch (111) has a first groove wall (1118) and a second groove wall (1119); the second groove wall (1119) is closer to the center of the cover plate (110) than the first groove wall (1118); 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 (1118) facing away from the second groove wall (1119).

31. The battery pack according to claim 30, 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 relative to each other at intervals, 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).

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